diff --git a/translated/tech/20171027 Share And Upload Files To Compatible Hosting Sites Automatically.md b/published/20171027 Share And Upload Files To Compatible Hosting Sites Automatically.md
similarity index 61%
rename from translated/tech/20171027 Share And Upload Files To Compatible Hosting Sites Automatically.md
rename to published/20171027 Share And Upload Files To Compatible Hosting Sites Automatically.md
index 55abfd75ff..fd24ef3c36 100644
--- a/translated/tech/20171027 Share And Upload Files To Compatible Hosting Sites Automatically.md
+++ b/published/20171027 Share And Upload Files To Compatible Hosting Sites Automatically.md
@@ -1,26 +1,28 @@
自动共享和上传文件到兼容的托管站点
======
-
-前阵子我们写了一个关于[**Transfer.sh**][1]的指南，它允许你使用命令行通过互联网来分享文件。今天，我们来看看另一种文件分享实用工具**Anypaste**。这是一个基于文件类型自动共享和上传文件到兼容托管站点的简单脚本。你不需要去手动登录到托管站点来上传或分享你的文件。Anypaste将会根据你想上传的文件的类型来**自动挑选合适的托管站点**。简单地说，照片将被上传到图像托管站点，视频被传到视频站点，代码被传到pastebins。难道不是很酷的吗？Anypaste是一个完全开源、免费、轻量的脚本，你可以通过命令行完成所有操作。因此，你不需要依靠那些臃肿的，需要消耗大量内存的GUI应用来上传和共享文件。
-### Anypaste-自动共享和上传文件到兼容的托管站点
-#### 安装
-正如我所说，这仅仅是一个脚本。所以不存在任何复杂的安装步骤。只需要将脚本下载后放置在你想要运行的位置(例如/usr/bin/anypaste)，并将其设置为可执行文件后就可以直接使用了。此外，你也可以通过下面的这两条命令来快速安装Anypaste。
+
+
+前阵子我们写了一个关于 [Transfer.sh][1]的指南，它允许你使用命令行通过互联网来分享文件。今天，我们来看看另一种文件分享实用工具 Anypaste。这是一个基于文件类型自动共享和上传文件到兼容托管站点的简单脚本。你不需要去手动登录到托管站点来上传或分享你的文件。Anypaste 将会根据你想上传的文件的类型来**自动挑选合适的托管站点**。简单地说，照片将被上传到图像托管站点，视频被传到视频站点，代码被传到 pastebin。难道不是很酷的吗？Anypaste 是一个完全开源、免费、轻量的脚本，你可以通过命令行完成所有操作。因此，你不需要依靠那些臃肿的、需要消耗大量内存的 GUI 应用来上传和共享文件。
+
+### 安装
+
+正如我所说，这仅仅是一个脚本。所以不存在任何复杂的安装步骤。只需要将脚本下载后放置在你想要运行的位置（例如 `/usr/bin/`），并将其设置为可执行文件后就可以直接使用了。此外，你也可以通过下面的这两条命令来快速安装 Anypaste。
+
```
sudo curl -o /usr/bin/anypaste https://anypaste.xyz/sh
-```
-```
sudo chmod +x /usr/bin/anypaste
```
-就是这样简单。如果需要更新老的Anypaste版本，只需要用新的可执行文件覆写旧的即可。
+就是这样简单。如果需要更新老的 Anypaste 版本，只需要用新的可执行文件覆写旧的即可。
现在，让我们看看一些实例。
-#### 配置
-Anypaste开箱即用，并不需要特别的配置。默认的配置文件是 **~/.config/anypaste.conf** ，这个文件在你第一次运行Anypaste时会自动创建。
+### 配置
-需要配置的选项只有**ap_plugins**。Anypaste使用插件系统去上传文件。每个站点(上传)都由一个特定的插件表示。你可以在anypaste.conf文件中的**ap-plugins directive**位置浏览可用的插件列表。
+Anypaste 开箱即用，并不需要特别的配置。默认的配置文件是 `~/.config/anypaste.conf`，这个文件在你第一次运行 Anypaste 时会自动创建。
+
+需要配置的选项只有 `ap_plugins`。Anypaste 使用插件系统上传文件。每个站点（的上传）都由一个特定的插件表示。你可以在 `anypaste.conf` 文件中的 `ap-plugins directive` 位置浏览可用的插件列表。
```
# List of plugins
@@ -42,13 +44,19 @@ ap_plugins=(
)
[...]
```
-如果你要安装一个新的插件，将它添加进这个列表中就可以了。如果你想禁用一个默认插件，只需要将它从列表中移除即可。如果多个插件是相互依存的关系，排列中的第一个会被选择，因此**顺序很重要**。
-#### 用法
-上传一个简单的文件，例如test.png，可以运行以下命令：
+
+如果你要安装一个新的插件，将它添加进这个列表中就可以了。如果你想禁用一个默认插件，只需要将它从列表中移除即可。如果有多个兼容的插件，排列中的第一个会被选择，因此**顺序很重要**。
+
+### 用法
+
+上传一个简单的文件，例如 `test.png`，可以运行以下命令：
+
```
anypaste test.png
```
-**输出示例：**
+
+输出示例：
+
```
Current file: test.png
Attempting to upload with plugin 'tinyimg'
@@ -59,9 +67,10 @@ Direct Link: https://tinyimg.io/i/Sa1zsjj.png
Upload complete.
All files processed. Have a nice day!
```
-正如输出结果中所看到的，Anypaste通过自动匹配图像文件**test.png**发现了兼容的托管站点(https://tinyimg.io)，并将文件上传到了该站点。此外，Anypaste也为我们提供了用于直接浏览/下载该文件的链接。
-不仅png格式文件，你还可以上传任何其他图片格式的文件。例如，下面的命令将会上传gif格式文件：
+正如输出结果中所看到的，Anypaste 通过自动匹配图像文件 `test.png` 发现了兼容的托管站点（https://tinyimg.io），并将文件上传到了该站点。此外，Anypaste 也为我们提供了用于直接浏览/下载该文件的链接。
+
+不仅是 png 格式文件，你还可以上传任何其他图片格式的文件。例如，下面的命令将会上传 gif 格式文件：
```
$ anypaste file.gif
@@ -78,17 +87,21 @@ Direct(ish) Link: https://thumbs.gfycat.com/MisguidedQuaintBergerpicard-size_res
Upload complete.
All files processed. Have a nice day!
```
-你可以将链接分享给你的家庭，朋友和同事们。下图是我刚刚将图片上传到**gfycat**网站的截图。
-[![][2]][3]
+你可以将链接分享给你的家庭、朋友和同事们。下图是我刚刚将图片上传到 gfycat 网站的截图。
+
+![][3]
也可以一次同时上传多个（相同格式或不同格式）文件。
下面的例子提供参考，这里我会上传两个不同的文件，包含一个图片文件和一个视频文件：
+
```
anypaste image.png video.mp4
```
-**输出示例：**
+
+输出示例：
+
```
Current file: image.png
Attempting to upload with plugin 'tinyimg'
@@ -109,13 +122,16 @@ Delete/Edit: http://sendvid.com/wwy7w96h?secret=39c0af2d-d8bf-4d3d-bad3-ad37432a
Upload complete.
All files processed. Have a nice day!
```
-Anypaste针对两个文件自动发现了与之相兼容的托管站点并成功上传。
-正如你在上述用法介绍部分的例子中注意到的，Anypaste会自动挑选最佳的插件。此外，你可以指定插件进行文件上传，这里提供一个上传**gfycat**类型文件的案例，运行以下命令：
+Anypaste 针对两个文件自动发现了与之相兼容的托管站点并成功上传。
+
+正如你在上述用法介绍部分的例子中注意到的，Anypaste 会自动挑选最佳的插件。此外，你可以指定插件进行文件上传，这里提供一个上传到 gfycat 的案例，运行以下命令：
+
```
anypaste -p gfycat file.gif
```
-**输出示例：**
+
+输出示例：
```
Current file: file.gif
@@ -131,15 +147,21 @@ Direct(ish) Link: https://thumbs.gfycat.com/GrayDifferentCollie-size_restricted.
Upload complete.
All files processed. Have a nice day!
```
+
如果要使用特定插件进行文件上传，可以通过以下命令绕过兼容性检查：
+
```
anypaste -fp gfycat file.gif
```
-如果你发现在配置文件中忽略了特定的插件，你仍然可以强制Anypaste去使用特定的插件，只不过需要加上'-xp'参数。
+
+如果你发现在配置文件中忽略了特定的插件，你仍然可以强制 Anypaste 去使用特定的插件，只不过需要加上 `-xp` 参数。
+
```
anypaste -xp gfycat file.gif
```
-如果想要以交互模式上传文件，可以在命令后加上'-i'标签：
+
+如果想要以交互模式上传文件，可以在命令后加上 `-i` 标签：
+
```
$ anypaste -i file.gif
Current file: file.gif
@@ -159,15 +181,16 @@ Direct(ish) Link: https://thumbs.gfycat.com/WaryAshamedBlackbear-size_restricted
Upload complete.
All files processed. Have a nice day!
```
-正如你所见，Anypaste首先询问了我是否需要自动确定插件。因为我不想自动寻找插件，所以我回复了'No'。之后，Anypaste列出了所有可选择的插件，并要求我从列表中选择一个。同样的，你可以上传和共享不同类型的文件，相关文件会被上传到相兼容的站点。
-无论你何时上传一个视频文件，Anypaste都会将其上传到以下站点中的一个：
+正如你所见，Anypaste 首先询问了我是否需要自动确定插件。因为我不想自动寻找插件，所以我回复了 “No”。之后，Anypaste 列出了所有可选择的插件，并要求我从列表中选择一个。同样的，你可以上传和共享不同类型的文件，相关文件会被上传到相兼容的站点。
+
+无论你何时上传一个视频文件，Anypaste 都会将其上传到以下站点中的一个：
1. sendvid
2. streamable
3. gfycat
-这里注意列表顺序，Anypaste将首先将文件上传到sendvid站点，如果没有sendvid的插件可供使用，Anypaste将会尝试顺序中的另外两个站点。当然你也可以通过更改配置文件来修改顺序。
+这里注意列表顺序，Anypaste 将首先将文件上传到 sendvid 站点，如果没有 sendvid 的插件可供使用，Anypaste 将会尝试顺序中的另外两个站点。当然你也可以通过更改配置文件来修改顺序。
图像文件上传站点：
@@ -195,8 +218,9 @@ All files processed. Have a nice day!
上面列出来的部分站点一段特定的时间后会删除上传的内容，所以在上传和分享内容时应先明确这些站点的条款和条件。
-#### 结论
-在我看来，识别文件并决定将其上传到何处的想法非常棒，而且开发者也以恰当的方式完美地实现了它。毫无疑问，Anypaste对那些在互联网上需要频繁分享文件的人们非常有用，我希望你也能这么觉得。
+### 结论
+
+在我看来，识别文件并决定将其上传到何处的想法非常棒，而且开发者也以恰当的方式完美地实现了它。毫无疑问，Anypaste 对那些在互联网上需要频繁分享文件的人们非常有用，我希望你也能这么觉得。
这就是今天的全部内容，后面会有越来越多的好东西分享给大家。再见啦！
@@ -206,7 +230,7 @@ via: https://www.ostechnix.com/anypaste-share-upload-files-compatible-hosting-si
作者：[SK][a]
译者：[lixin555](https://github.com/lixin555)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/published/20181018 Think global- How to overcome cultural communication challenges.md b/published/20181018 Think global- How to overcome cultural communication challenges.md
new file mode 100644
index 0000000000..5b214ec331
--- /dev/null
+++ b/published/20181018 Think global- How to overcome cultural communication challenges.md
@@ -0,0 +1,95 @@
+全球化思考:怎样克服交流中的文化差异
+======
+
+> 这有一些建议帮助你的全球化开发团队能够更好地理解你们的讨论并能参与其中。
+
+
+
+几周前，我见证了两位同事之间一次有趣的互动，他们分别是 Jason，我们的一位美国员工，和 Raj，一位来自印度的访问工作人员。
+
+Raj 在印度时，他一般会通过电话参加美国中部时间上午 9 点的每日立会，现在他到美国工作了，就可以和组员们坐在同一间会议室里开会了。Jason 拦下了 Raj，说：“Raj 你要去哪？你不是一直和我们开电话会议吗？你突然出现在会议室里我还不太适应。” Raj 听了说，“是这样吗？没问题。”就回到自己工位前准备和以前一样参加电话会议了。
+
+我去找 Raj，问他为什么不去参加每日立会，Raj 说 Jason 让自己给组员们打电话参会，而与此同时，Jason 也在会议室等着 Raj 来参加立会。
+
+到底是哪里出的问题？Jason 明显只是调侃 Raj 终于能来一起开会了，为什么 Raj 没能听懂呢？
+
+Jason 明显是在开玩笑，但 Raj 把它当真了。这就是在两人互相不了解对方文化语境时发生的一个典型误会。
+
+我经常会遇到有人在电子邮件的末尾写“请复原”，最开始我很迷惑，“这有什么需要我复原的内容？”后来我才搞懂，“请复原”其实是“请回复”的意思。
+
+在 Ricardo Fernandez 的TED 演讲“[如何管理跨文化团队][1]” 中，他提到了自己与一位南非同事发生的小故事。那位同事用一句“我一会给你打电话。”结束了两人的 IM 会话，Ricardo 回到办公室后就开始等这位同事的电话，十五分钟后他忍不住主动给这位同事打了电话，问他:“你不是说要给我打电话吗？”，这位同事答到:“是啊，我是说以后有机会给你打电话。”这时 Ricardo 才理解那位同事说的“一会”是“以后”的意思。
+
+现在是全球化时代，我们的同事很可能不跟我们面对面接触，甚至不在同一座城市，来自不同的国家。越来越多的技术公司拥有全球化的工作场所，和来自世界各地的员工，他们有着不同的背景和经历。这种多样性使得技术公司能够在这个快速发展的科技大环境下拥有更强的竞争力。
+
+但是这种地域的多样性也会给团队带来挑战。管理和维持高性能的团队发展对于同地协作的团队来说就有着很大难度，对于有着多样背景成员的全球化团队来说，无疑更加困难。成员之间的交流会发生延迟，误解时有发生，成员之间甚至会互相怀疑，这些都会影响着公司的成功。
+
+到底是什么因素让全球化交流间发生误解呢？我们可以参照 Erin Meyer 的书《[文化地图][2]》，她在书中将全球文化分为八个类型，其中美国文化被分为低语境文化，与之相对的，日本为高语境文化。
+
+看到这里你可能会问，高、低语境文化到底是什么意思？美国人从小就教育孩子们简洁表达，“直言不讳”是他们的表达准则；另一边，日本人从小学习在高效处理社交线索的同时进行交流，“察言观色”是他们的交流习惯。
+
+大部分亚洲国家的文化都属于高语境文化。作为一个年轻的移民国家，美国毫不意外地拥有着低语境文化。移民来自于世界各地，拥有着不同的文化背景，他们不得不选择简洁而直接的交流方式，这或许就是其拥有低语境文化的原因。
+
+### 从文化语境的角度与异国同事交流的三个步骤：
+
+怎样面临跨文化交流中遇到的挑战？比如说一位美国人与他的日本同事交流，他更应该注重日本同事的非语言线索，同样的日本同事应当更关注美国人直接表达出的信息。如果你也面临类似的挑战，按照下面这三个步骤做，可以帮助你更有效地和异国同事交流，增进与他们的感情。
+
+#### 认识到文化语境的差异
+
+跨文化交流的第一步是认识到文化差异，跨文化交流从认识其他文化开始。
+
+#### 尊重文化语境的差异
+
+一旦你意识到了文化语境的差异会影响跨文化交流，你要做的就是尊重这些差异。在你遇到一种不同的交流方式时，学会接受差异，学会积极听取他人意见。
+
+#### 调和文化语境的差异
+
+只是认识和尊重差异还远远不够，你还需要学会如何调和这些差异。互相理解和换位思考可以增进差异的调和，你还要学着用它们去提高同事间的交流效率，推动生产力。
+
+### 五种促进不同文化语境间交流的方法
+
+为了加强组员们之间关系，这么多年来我一直在收集各种各样的方法和建议。这些方法帮助我解决了与外国组员间产生的很多交流问题，下面有其中一些例子：
+
+#### 与外国组员交流时尽量使用视频会议的形式
+
+研究表明，交流中约 55% 的内容不是靠语言传递的。肢体语言传达着一种十分微妙的信息，你可以根据它们理解对方的意思，而视频会议中处于异地的组员们能够看到对方的肢体语言。因此，组织远程会议时我一般都会采用视频会议的形式。
+
+#### 确保每位成员都有机会分享他们的想法
+
+我虽然喜欢开视频会议，但不是每次都能开的成。如果视频会议对你的团队来说并不常用，大家可能要一些时间去适应，你需要积极鼓励大家参与到其中，先从进行语音会议开始。
+
+我们有一个外地的组员，每次都和我们进行语音会议，和我们提到她经常会有些想法想要分享，或者想做些贡献，但是我们互相看不到，她不知道该怎样开口。如果你一直在进行语音会议，注意要给组员们足够的时间和机会分享他们的想法。
+
+#### 互相学习
+
+通过你身边一两名外国朋友来学习他们的文化，你可以把从一位同事身上学到的应用于所有来自这个国家的同事。我有几位南亚和南美的同事，他们帮助我理解他们的文化，而这些也使得我更加专业。
+
+对编程人员来说，我建议请你全世界的同行们检查你的代码，这个过程能让你观察到其他文化中人们怎样进行反馈、劝说他人，和最终进行技术决策。
+
+#### 学会感同身受
+
+同理心是一段牢固关系的核心。你越能换位思考，就越容易获得信任，来建立长久的关系。你可以在每次会议开始之前和大家闲聊几句，这样大家更容易处于一个放松的状态，如果团队中有很多外国人，要确保大家都能参与进来。
+
+#### 和你的外国同事们单独见面
+
+保持长久关系最好的方法是和你的组员们单独见面。如果你的公司可以报销这些费用，那么努力去和组员们见面吧。和一起工作了很长时间的组员们见面能够使你们的关系更加坚固。我所在的公司就有着周期性交换员工的传统，每隔一段时间，世界各地的员工就会来到美国工作，美国员工再到其他分部工作。
+
+另一种聚齐组员们的机会是研讨会。研讨会创造的不仅是学习和培训的机会，你还可以挤出一些时间和组员们培养感情。
+
+在如今，全球化经济不断发展，拥有来自不同国家和地区的员工对维持一个公司的竞争力来说越来越重要。即使组员们来自世界各地，团队中会出现一些交流问题，但拥有一支国际化的高绩效团队不是问题。如果你在工作中有什么促进团队交流的小窍门，请在评论中告诉我们吧。
+
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/18/10/think-global-communication-challenges
+
+作者：[Avindra Fernando][a]
+选题：[lujun9972][b]
+译者：[Valoniakim](https://github.com/Valoniakim)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/avindrafernando
+[b]: https://github.com/lujun9972
+[1]: https://www.youtube.com/watch?v=QIoAkFpN8wQ
+[2]: https://www.amazon.com/The-Culture-Map-Invisible-Boundaries/dp/1610392507
diff --git a/published/20181231 Easily Upload Text Snippets To Pastebin-like Services From Commandline.md b/published/20181231 Easily Upload Text Snippets To Pastebin-like Services From Commandline.md
new file mode 100644
index 0000000000..d92f3a4b24
--- /dev/null
+++ b/published/20181231 Easily Upload Text Snippets To Pastebin-like Services From Commandline.md
@@ -0,0 +1,247 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11691-1.html)
+[#]: subject: (Easily Upload Text Snippets To Pastebin-like Services From Commandline)
+[#]: via: (https://www.ostechnix.com/how-to-easily-upload-text-snippets-to-pastebin-like-services-from-commandline/)
+[#]: author: (SK https://www.ostechnix.com/author/sk/)
+
+从命令行轻松将文本片段上传到类似 Pastebin 的服务中
+======
+
+
+
+每当需要在线共享代码片段时，我们想到的第一个便是 Pastebin.com，这是 Paul Dixon 于 2002 年推出的在线文本共享网站。现在，有几种可供选择的文本共享服务可以上传和共享文本片段、错误日志、配置文件、命令输出或任何类型的文本文件。如果你碰巧经常使用各种类似于 Pastebin 的服务来共享代码，那么这对你来说确实是个好消息。向 Wgetpaste 打个招呼吧，它是一个命令行 BASH 实用程序，可轻松地将文本摘要上传到类似 Pastebin 的服务中。使用 Wgetpaste 脚本，任何人都可以与自己的朋友、同事或想在类似 Unix 的系统中的命令行中查看/使用/审查代码的人快速共享文本片段。
+
+### 安装 Wgetpaste
+
+Wgetpaste 在 Arch Linux [Community] 存储库中可用。要将其安装在 Arch Linux 及其变体（如 Antergos 和 Manjaro Linux）上，只需运行以下命令：
+
+```
+$ sudo pacman -S wgetpaste
+```
+
+对于其他发行版，请从 [Wgetpaste 网站][1] 获取源代码，并按如下所述手动安装。
+
+首先下载最新的 Wgetpaste tar 文件：
+
+```
+$ wget http://wgetpaste.zlin.dk/wgetpaste-2.28.tar.bz2
+```
+
+提取它：
+
+```
+$ tar -xvjf wgetpaste-2.28.tar.bz2
+```
+
+它将 tar 文件的内容提取到名为 `wgetpaste-2.28` 的文件夹中。
+
+转到该目录：
+
+```
+$ cd wgetpaste-2.28/
+```
+
+将 `wgetpaste` 二进制文件复制到 `$PATH` 中，例如 `/usr/local/bin/`。
+
+```
+$ sudo cp wgetpaste /usr/local/bin/
+```
+
+最后，使用命令使其可执行：
+
+```
+$ sudo chmod +x /usr/local/bin/wgetpaste
+```
+
+### 将文本片段上传到类似 Pastebin 的服务中
+
+使用 Wgetpaste 上传文本片段很简单。让我向你展示一些示例。
+
+#### 1、上传文本文件
+
+要使用 Wgetpaste 上传任何文本文件，只需运行：
+
+```
+$ wgetpaste mytext.txt
+```
+
+此命令将上传 `mytext.txt` 文件的内容。
+
+示例输出：
+
+```
+Your paste can be seen here: https://paste.pound-python.org/show/eO0aQjTgExP0wT5uWyX7/
+```
+
+
+
+你可以通过邮件、短信、whatsapp 或 IRC 等任何媒体共享 pastebin 的 URL。拥有此 URL 的人都可以访问它，并在他们选择的 Web 浏览器中查看文本文件的内容。
+
+这是 Web 浏览器中 `mytext.txt` 文件的内容：
+
+
+
+你也可以使用 `tee` 命令显示粘贴的内容，而不是盲目地上传它们。
+
+为此，请使用如下的 `-t` 选项。
+
+```
+$ wgetpaste -t mytext.txt
+```
+
+![][3]
+
+#### 2、将文字片段上传到其他服务
+
+默认情况下，Wgetpaste 会将文本片段上传到 poundpython（）服务。
+
+要查看支持的服务列表，请运行：
+
+```
+$ wgetpaste -S
+```
+
+示例输出：
+
+```
+Services supported: (case sensitive):
+Name: | Url:
+=============|=================
+bpaste | https://bpaste.net/
+codepad | http://codepad.org/
+dpaste | http://dpaste.com/
+gists | https://api.github.com/gists
+*poundpython | https://paste.pound-python.org/
+```
+
+在这里，`*` 表示默认服务。
+
+如你所见，Wgetpaste 当前支持五种文本共享服务。我并没有全部尝试，但是我相信所有服务都可以使用。
+
+要将内容上传到其他服务，例如 bpaste.net，请使用如下所示的 `-s` 选项。
+
+```
+$ wgetpaste -s bpaste mytext.txt
+Your paste can be seen here: https://bpaste.net/show/5199e127e733
+```
+
+#### 3、从标准输入读取输入
+
+Wgetpaste 也可以从标准输入读取。
+
+```
+$ uname -a | wgetpaste
+```
+
+此命令将上传 `uname -a` 命令的输出。
+
+#### 4、上传命令及命令的输出
+
+有时，你可能需要粘贴命令及其输出。为此，请在如下所示的引号内指定命令的内容。
+
+```
+$ wgetpaste -c 'ls -l'
+```
+
+这会将命令 `ls -l` 及其输出上传到 pastebin 服务。
+
+当你想让其他人清楚地知道你刚运行的确切命令及其输出时，此功能很有用。
+
+![][4]
+
+如你在输出中看到的，我运行了 `ls -l` 命令。
+
+#### 5、上载系统日志文件、配置文件
+
+就像我已经说过的，我们可以上载你的系统中任何类型的文本文件，而不仅仅是普通的文本文件，例如日志文件、特定命令的输出等。例如，你刚刚更新了 Arch Linux 机器，最后系统损坏了。你问你的同事该如何解决此问题，他（她）想阅读 `pacman.log` 文件。 这是上传 `pacman.log` 文件内容的命令：
+
+```
+$ wgetpaste /var/log/pacman.log
+```
+
+与你的同事共享 pastebin URL，以便他/她可以查看 `pacman.log`，并通过查看日志文件来帮助你解决问题。
+
+通常，日志文件的内容可能太长，你不希望全部共享它们。在这种情况下，只需使用 `cat` 命令读取输出，然后使用 `tail -n` 命令定义要共享的行数，最后将输出通过管道传递到 Wgetpaste，如下所示。
+
+```
+$ cat /var/log/pacman.log | tail -n 50 | wgetpaste
+```
+
+上面的命令将仅上传 `pacman.log` 文件的“最后 50 行”。
+
+#### 6、将输入网址转换为短链接
+
+默认情况下，Wgetpaste 将在输出中显示完整的 pastebin URL。如果要将输入 URL 转换为短链接，只需使用 `-u` 选项。
+
+```
+$ wgetpaste -u mytext.txt
+Your paste can be seen here: http://tinyurl.com/y85d8gtz
+```
+
+#### 7、设定语言
+
+默认情况下，Wgetpaste 将上传“纯文本”中的文本片段。
+
+要列出指定服务支持的语言，请使用 `-L` 选项。
+
+```
+$ wgetpaste -L
+```
+
+该命令将列出默认服务（poundpython ）支持的所有语言。
+
+我们可以使用 `-l` 选项来改变它。
+
+```
+$ wgetpaste -l Bash mytext.txt
+```
+
+#### 8、在输出中禁用语法突出显示或 html
+
+如上所述，文本片段将以特定的语言格式（纯文本、Bash 等）显示。
+
+但是，你可以更改此行为，以使用 `-r` 选项显示原始文本摘要。
+
+```
+$ wgetpaste -r mytext.txt
+Your raw paste can be seen here: https://paste.pound-python.org/raw/CUJhQ3jEmr2UvfmD2xCL/
+```
+
+
+
+如你在上面的输出中看到的，没有语法突出显示，没有 html 格式。只是原始输出。
+
+#### 9、更改 Wgetpaste 默认值
+
+所有默认值（`DEFAULT_{NICK,LANGUAGE,EXPIRATION}[_${SERVICE}]` 和 `DEFAULT_SERVICE`）都可以在 `/etc/wgetpaste.conf` 中全局更改，也可以在 `~/.wgetpaste.conf` 文件中针对每个用户更改。但是，这些文件在我的系统中默认情况下并不存在。我想我们需要手动创建它们。开发人员已经在[这里][5]和[这里][6]为这两个文件提供了示例内容。只需使用给定的样本内容手动创建这些文件，并相应地修改参数即可更改 Wgetpaste 的默认设置。
+
+#### 10、获得帮助
+
+要显示帮助部分，请运行：
+
+```
+$ wgetpaste -h
+```
+
+--------------------------------------------------------------------------------
+
+via: https://www.ostechnix.com/how-to-easily-upload-text-snippets-to-pastebin-like-services-from-commandline/
+
+作者：[SK][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.ostechnix.com/author/sk/
+[b]: https://github.com/lujun9972
+[1]: http://wgetpaste.zlin.dk/
+[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
+[3]: http://www.ostechnix.com/wp-content/uploads/2018/12/wgetpaste-3.png
+[4]: http://www.ostechnix.com/wp-content/uploads/2018/12/wgetpaste-4.png
+[5]: http://wgetpaste.zlin.dk/zlin.conf
+[6]: http://wgetpaste.zlin.dk/wgetpaste.example
diff --git a/published/20190217 Install Android 8.1 Oreo on Linux To Run Apps - Games.md b/published/20190217 Install Android 8.1 Oreo on Linux To Run Apps - Games.md
new file mode 100644
index 0000000000..3babf263f3
--- /dev/null
+++ b/published/20190217 Install Android 8.1 Oreo on Linux To Run Apps - Games.md
@@ -0,0 +1,207 @@
+[#]: collector: (lujun9972)
+[#]: translator: (robsean)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11711-1.html)
+[#]: subject: (Install Android 8.1 Oreo on Linux To Run Apps & Games)
+[#]: via: (https://fosspost.org/tutorials/install-android-8-1-oreo-on-linux)
+[#]: author: (Python Programmer;Open Source Software Enthusiast. Worked On Developing A Lot Of Free Software. The Founder Of Foss Post;Foss Project. Computer Science Major. )
+
+在 Linux 上安装安卓 8.1 Oreo 来运行应用程序和游戏
+======
+
+
+
+[android x86][1] 是一个自由而开源的项目，将谷歌制作的安卓系统从 ARM 架构移植到了 x86 架构，可以让用户在他们的桌面电脑上运行安卓系统来享受所有的安卓功能和应用程序及游戏。
+
+在前一段时间，android x86 项目完成了安卓 8.1 Oreo 系统的 x86 架构移植。在这篇文章中，我们将解释如何在你的 Linux 系统上安装它，以便你能够随时使用你的安卓 用程序和游戏。
+
+### 在 Linux 上安装安卓 x86 8.1 Oreo
+
+#### 准备环境
+
+首先，让我们下载 android x86 8.1 Oreo 系统镜像。你可以从[这个页面][2]下载它，只需单击 “android-x86_64-8.1-r1.iso” 文件下的 “View” 按钮。
+
+我们将在我们的 Linux 系统上使用 QEMU 来运行 android x86。QEMU 是一个非常好的模拟器软件，它也是自由而开源的，并且在所有主要的 Linux 发行版存储库中都是可用的。
+
+在 Ubuntu/Linux Mint/Debian 上安装 QEMU：
+
+```
+sudo apt-get install qemu qemu-kvm libvirt-bin
+```
+
+在 Fedora 上安装 QEMU：
+
+```
+sudo dnf install qemu qemu-kvm
+```
+
+对于其它发行版，只需要搜索 “qemu” 和 “qemu-kvm” 软件包，并安装它们。
+
+在你安装 QEMU 后，我们将需要运行下面的命令来创建 `android.img` 文件，它就像某种分配给安卓系统的磁盘空间。所有安卓文件和系统都将位于该镜像文件中：
+
+```
+qemu-img create -f qcow2 android.img 15G
+```
+
+我们在这里的意思是，我们想为该安卓系统分配一个最大 15GB 的磁盘空间，但是，你可以更改它到你想要的任意大小（确保它至少大于 5GB）。
+
+现在，首次启动运行该安卓系统，运行：
+
+```
+sudo qemu-system-x86_64 -m 2048 -boot d -enable-kvm -smp 3 -net nic -net user -hda android.img -cdrom /home/mhsabbagh/android-x86_64-8.1-r1.iso
+```
+
+将 `/home/mhsabbagh/android-x86_64-8.1-r1.iso` 替换为你从 android x86 网站下载的文件的路径。关于我们在这里正在使用的其它选项的解释，你可以参考[这篇文章][3]。
+
+在你运行上面的命令后，该安卓系统将启动：
+
+![][4]
+
+#### 安装系统
+
+从这个窗口中，选择 “Advanced options”, 它将引导到下面的菜单，你应如下在其中选择 “Auto_installation” ：
+
+![][5]
+
+在这以后，安装器将告知你是否想要继续，选择 “Yes”：
+
+![][6]
+
+接下来，安装器将无需你的指示而继续进行：
+
+![][7]
+
+最后，你将收到这个信息，它表示你已经成功安装安卓 8.1 ：
+
+![][8]
+
+现在，关闭 QEMU 窗口即可。
+
+#### 启动和使用 安卓 8.1 Oreo
+
+现在，安卓系统已经完全安装在你的 `android.img` 文件中，你应该使用下面的 QEMU 命令来启动它，而不是前面的命令：
+
+```
+sudo qemu-system-x86_64 -m 2048 -boot d -enable-kvm -smp 3 -net nic -net user -hda android.img
+```
+
+注意，我们所做的只是移除 `-cdrom` 选项及其参数。这是告诉 QEMU，我们不再想从我们下载的 ISO 文件启动，相反，从这个安装的安卓系统启动。
+
+你现在能够看到安卓的启动菜单：
+
+![][9]
+
+然后，你将进入第一个准备向导，选择你的语言并继续：
+
+![][10]
+
+从这里，选择 “Set up as new” 选项：
+
+![][11]
+
+然后，安卓将询问你是否想登录到你当前的谷歌账号。这步骤是可选的，但是这很重要，以便你随后可以使用谷歌 Play 商店：
+
+![][12]
+
+然后，你将需要接受条款：
+
+![][13]
+
+现在，你可以选择你当前的时区：
+
+![][14]
+
+系统将询问你是否想启动一些数据收集功能。如果我是你的话，我将简单地全部关闭它们，像这样：
+
+![][15]
+
+最后，你将有两种启动类型可供选择，我建议你选择 Launcher3 选项，并使其成为默认项：
+
+![][16]
+
+然后，你将看到完整工作的安卓系统主屏幕：
+
+![][17]
+
+从现在起，你可以做你想做的任何事情；你可以使用内置的安卓应用程序，或者你可以浏览你的系统设置来根据你的喜好进行调整。你可以更改你的系统的外观和体验，或者你可以像示例一样运行 Chrome ：
+
+![][18]
+
+你可以开始从谷歌 Play 商店安装一些应用程序程序，像 WhatsApp 和其它的应用程序，以供你自己使用：
+
+![][19]
+
+你现在可以用你的系统做任何你想做的事。恭喜！
+
+### 以后如何轻松地运行安卓 8.1 Oreo
+
+我们不想总是不得不打开终端窗口，并写那些长长的 QEMU 命令来运行安卓系统，相反，我们想在我们需要时一次单击就运行它。
+
+为此，我们将使用下面的命令在 `/usr/share/applications` 下创建一个名为 `android.desktop` 的新文件：
+
+```
+sudo nano /usr/share/applications/android.desktop
+```
+
+并在其中粘贴下面的内容（右键单击然后粘贴）：
+
+```
+[Desktop Entry]
+Name=Android 8.1
+Comment=Run Android 8.1 Oreo on Linux using QEMU
+Icon=phone
+Exec=bash -c 'pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY qemu-system-x86_64 -m 2048 -boot d -enable-kvm -smp 3 -net nic -net user -hda /home/mhsabbagh/android.img'
+Terminal=false
+Type=Application
+StartupNotify=true
+Categories=GTK;
+```
+
+再强调一次，你必需使用你系统上的本地镜像路径来替换 `/home/mhsabbagh/android.img` 。然后保存文件（`Ctrl+X`，然后按 `Y`，然后按回车）。
+
+注意，我们需要使用 `pkexec` 来使用 root 权限运行 QEMU ，因为从较新的版本开始，普通用户不允许通过 libvirt 访问 KVM 技术；这就是为什么它将每次要求你输入 root 密码的原因。
+
+现在，你将在应用程序菜单中看到安卓图标，你可以在你想使用安卓的任何时间来简单地单击该图标，QEMU 程序将启动：
+
+![][20]
+
+### 总结
+
+我们向你展示如何在你的 Linux 系统上安装和运行安卓 8.1 Oreo 。从现在起，在没有其它一些软件的（像 Blutsticks 和类似的方法）的情况下，你可以更容易地完成基于安卓的任务。在这里，你有一个完整工作和功能的安卓系统，你可以随心所欲地操作它，如果一些东西出错，你可以简单地干掉该镜像文件，然后随时再一次重新运行安装程序。
+
+你之前尝试过 android x86 吗？你的体验如何？
+
+--------------------------------------------------------------------------------
+
+via: https://fosspost.org/tutorials/install-android-8-1-oreo-on-linux
+
+作者：[M.Hanny Sabbagh][a]
+选题：[lujun9972][b]
+译者：[robsean](https://github.com/robsean)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fosspost.org/author/mhsabbagh
+[b]: https://github.com/lujun9972
+[1]: http://www.android-x86.org/
+[2]: http://www.android-x86.org/download
+[3]: https://fosspost.org/tutorials/use-qemu-test-operating-systems-distributions
+[4]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-16.png?resize=694%2C548&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 40 android 8.1 oreo on linux)
+[5]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-15.png?resize=673%2C537&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 42 android 8.1 oreo on linux)
+[6]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-14.png?resize=769%2C469&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 44 android 8.1 oreo on linux)
+[7]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-13.png?resize=767%2C466&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 46 android 8.1 oreo on linux)
+[8]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-12.png?resize=750%2C460&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 48 android 8.1 oreo on linux)
+[9]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-11.png?resize=754%2C456&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 50 android 8.1 oreo on linux)
+[10]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-10.png?resize=850%2C559&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 52 android 8.1 oreo on linux)
+[11]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-09.png?resize=850%2C569&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 54 android 8.1 oreo on linux)
+[12]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-08.png?resize=850%2C562&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 56 android 8.1 oreo on linux)
+[13]: https://i2.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-07-1.png?resize=850%2C561&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 58 android 8.1 oreo on linux)
+[14]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-06.png?resize=850%2C569&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 60 android 8.1 oreo on linux)
+[15]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-05.png?resize=850%2C559&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 62 android 8.1 oreo on linux)
+[16]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-04.png?resize=850%2C553&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 64 android 8.1 oreo on linux)
+[17]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-03.png?resize=850%2C571&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 66 android 8.1 oreo on linux)
+[18]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-02.png?resize=850%2C555&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 68 android 8.1 oreo on linux)
+[19]: https://i2.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-01.png?resize=850%2C557&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 70 android 8.1 oreo on linux)
+[20]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Screenshot-at-2019-02-17-1539.png?resize=850%2C557&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 72 android 8.1 oreo on linux)
diff --git a/published/20190225 Netboot a Fedora Live CD.md b/published/20190225 Netboot a Fedora Live CD.md
new file mode 100644
index 0000000000..928f1eeed8
--- /dev/null
+++ b/published/20190225 Netboot a Fedora Live CD.md
@@ -0,0 +1,183 @@
+[#]: collector: (lujun9972)
+[#]: translator: (robsean)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11708-1.html)
+[#]: subject: (Netboot a Fedora Live CD)
+[#]: via: (https://fedoramagazine.org/netboot-a-fedora-live-cd/)
+[#]: author: (Gregory Bartholomew https://fedoramagazine.org/author/glb/)
+
+网络启动一个 Fedora Live CD
+======
+
+
+
+[Live CD][1] 对于很多任务是很有用的，例如:
+
+* 将操作系统安装到一个硬盘驱动器
+* 修复一个启动加载程序或执行其它救援模式操作
+* 为 Web 浏览提供一个相适应的最小环境
+* …以及[更多的东西][2]。
+
+作为使用 DVD 和 USB 驱动器来存储你的 Live CD 镜像是一个替代方案，你可以上传它们到一个不太可能丢失或损坏的 [iSCSI][3] 服务器中。这个指南向你展示如何加载你的 Live CD 镜像到一个 ISCSI 服务器上，并使用 [iPXE][4] 启动加载程序来访问它们。
+
+### 下载一个 Live CD 镜像
+
+```
+$ MY_RLSE=27
+$ MY_LIVE=$(wget -q -O - https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/$MY_RLSE/Workstation/x86_64/iso | perl -ne '/(Fedora[^ ]*?-Live-[^ ]*?\.iso)(?{print $^N})/;')
+$ MY_NAME=fc$MY_RLSE
+$ wget -O $MY_NAME.iso https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/$MY_RLSE/Workstation/x86_64/iso/$MY_LIVE
+```
+
+上面的命令下载 `Fedora-Workstation-Live-x86_64-27-1.6.iso` Fedora Live 镜像，并保存为 `fc27.iso`。更改 `MY_RLSE` 的值来下载其它档案版本。或者，你可以浏览 来下载最新的 Fedora live 镜像。在 21 之前的版本使用不同的命名约定，必需[在这里手动下载][5]。如果你手动下载一个 Live CD 镜像，设置 `MY_NAME` 变量为不带有扩展名的文件的基本名称。用此方法，下面部分中命令将引用正确的文件。
+
+### 转换 Live CD 镜像
+
+使用 `livecd-iso-to-disk` 工具来转换 ISO 文件为一个磁盘镜像，并添加 `netroot` 参数到嵌入的内核命令行：
+
+```
+$ sudo dnf install -y livecd-tools
+$ MY_SIZE=$(du -ms $MY_NAME.iso | cut -f 1)
+$ dd if=/dev/zero of=$MY_NAME.img bs=1MiB count=0 seek=$(($MY_SIZE+512))
+$ MY_SRVR=server-01.example.edu
+$ MY_RVRS=$(echo $MY_SRVR | tr '.' "\n" | tac | tr "\n" '.' | cut -b -${#MY_SRVR})
+$ MY_LOOP=$(sudo losetup --show --nooverlap --find $MY_NAME.img)
+$ sudo livecd-iso-to-disk --format --extra-kernel-args netroot=iscsi:$MY_SRVR:::1:iqn.$MY_RVRS:$MY_NAME $MY_NAME.iso $MY_LOOP
+$ sudo losetup -d $MY_LOOP
+```
+
+### 上传 Live 镜像到你的服务器
+
+在你的 ISCSI 服务器上创建一个目录来存储你的 live 镜像，随后上传你修改的镜像到其中。
+
+对于 21 及更高发布版本：
+
+```
+$ MY_FLDR=/images
+$ scp $MY_NAME.img $MY_SRVR:$MY_FLDR/
+```
+
+对于 21 以前发布版本：
+
+```
+$ MY_FLDR=/images
+$ MY_LOOP=$(sudo losetup --show --nooverlap --find --partscan $MY_NAME.img)
+$ sudo tune2fs -O ^has_journal ${MY_LOOP}p1
+$ sudo e2fsck ${MY_LOOP}p1
+$ sudo dd status=none if=${MY_LOOP}p1 | ssh $MY_SRVR "dd of=$MY_FLDR/$MY_NAME.img"
+$ sudo losetup -d $MY_LOOP
+```
+
+### 定义 iSCSI 目标
+
+在你的 iSCSI 服务器上运行下面的命令：
+
+```
+$ sudo -i
+# MY_NAME=fc27
+# MY_FLDR=/images
+# MY_SRVR=`hostname`
+# MY_RVRS=$(echo $MY_SRVR | tr '.' "\n" | tac | tr "\n" '.' | cut -b -${#MY_SRVR})
+# cat << END > /etc/tgt/conf.d/$MY_NAME.conf
+
+ backing-store $MY_FLDR/$MY_NAME.img
+ readonly 1
+ allow-in-use yes
+
+END
+# tgt-admin --update ALL
+```
+
+### 创建一个可启动 USB 驱动器
+
+[iPXE][4] 启动加载程序有一个 [sanboot][6] 命令，你可以使用它来连接并启动托管于你 ISCSI 服务器上运行的 live 镜像。它可以以很多不同的[格式][7]编译。最好的工作格式依赖于你正在运行的硬件。例如，下面的说明向你展示如何在一个 USB 驱动器上从 [syslinux][9] 中 [链式加载][8] iPXE。
+
+首先，下载 iPXE，并以它的 lkrn 格式构建。这应该作为一个工作站上的普通用户完成：
+
+```
+$ sudo dnf install -y git
+$ git clone http://git.ipxe.org/ipxe.git $HOME/ipxe
+$ sudo dnf groupinstall -y "C Development Tools and Libraries"
+$ cd $HOME/ipxe/src
+$ make clean
+$ make bin/ipxe.lkrn
+$ cp bin/ipxe.lkrn /tmp
+```
+
+接下来，准备一个带有一个 MSDOS 分区表和一个 FAT32 文件系统的 USB 驱动器。下面的命令假设你已经连接将要格式化的 USB 驱动器。**注意：你要格式正确的驱动器！**
+
+```
+$ sudo -i
+# dnf install -y parted util-linux dosfstools
+# echo; find /dev/disk/by-id ! -regex '.*-part.*' -name 'usb-*' -exec readlink -f {} \; | xargs -i bash -c "parted -s {} unit MiB print | perl -0 -ne '/^Model: ([^(]*).*\n.*?([0-9]*MiB)/i && print \"Found: {} = \$2 \$1\n\"'"; echo; read -e -i "$(find /dev/disk/by-id ! -regex '.*-part.*' -name 'usb-*' -exec readlink -f {} \; -quit)" -p "Drive to format: " MY_USB
+# umount $MY_USB?
+# wipefs -a $MY_USB
+# parted -s $MY_USB mklabel msdos mkpart primary fat32 1MiB 100% set 1 boot on
+# mkfs -t vfat -F 32 ${MY_USB}1
+```
+
+最后，在 USB 驱动器上安装并配置 syslinux ，来链式加载 iPXE：
+
+```
+# dnf install -y syslinux-nonlinux
+# syslinux -i ${MY_USB}1
+# dd if=/usr/share/syslinux/mbr.bin of=${MY_USB}
+# MY_MNT=$(mktemp -d)
+# mount ${MY_USB}1 $MY_MNT
+# MY_NAME=fc27
+# MY_SRVR=server-01.example.edu
+# MY_RVRS=$(echo $MY_SRVR | tr '.' "\n" | tac | tr "\n" '.' | cut -b -${#MY_SRVR})
+# cat << END > $MY_MNT/syslinux.cfg
+ui menu.c32
+default $MY_NAME
+timeout 100
+menu title SYSLINUX
+label $MY_NAME
+ menu label ${MY_NAME^^}
+ kernel ipxe.lkrn
+ append dhcp && sanboot iscsi:$MY_SRVR:::1:iqn.$MY_RVRS:$MY_NAME
+END
+# cp /usr/share/syslinux/menu.c32 $MY_MNT
+# cp /usr/share/syslinux/libutil.c32 $MY_MNT
+# cp /tmp/ipxe.lkrn $MY_MNT
+# umount ${MY_USB}1
+```
+
+通过简单地编辑 `syslinux.cfg` 文件，并添加附加的菜单项，你应该能够使用这同一个 USB 驱动器来网络启动附加的 ISCSI 目标。
+
+这仅是加载 IPXE 的一种方法。你可以直接在你的工作站上安装 syslinux 。再一种选项是编译 iPXE 为一个 EFI 可执行文件，并直接放置它到你的 [ESP][10] 中。又一种选项是编译 iPXE 为一个 PXE 加载器，并放置它到你的能够被 DHCP 引用的 TFTP 服务器。最佳的选项依赖于的环境
+
+### 最后说明
+
+* 如果你以 IPXE 的 EFI 格式编译 IPXE ，你可能想添加 `–filename \EFI\BOOT\grubx64.efi` 参数到 `sanboot` 命令。
+* 能够创建自定义 live 镜像。更多信息参考[创建和使用 live CD][11]。
+* 可以添加 `–overlay-size-mb` 和 `–home-size-mb` 参数到 `livecd-iso-to-disk` 命令来创建永久存储的 live 镜像。然而，如果你有多个并发用户，你将需要设置你的 ISCSI 服务器来管理独立的每个用户的可写覆盖。这与 “[如何构建一个网络启动服务器，部分 4][12]” 一文所示类似。
+* Live 镜像在它们的内核命令行中支持一个 `persistenthome` 选项（例如， `persistenthome=LABEL=HOME`）。与经过 CHAP 身份验证的 iSCSI 目标一起使用，对于中心控制主目录，`persistenthome` 选项为 NFS 提供一个有趣的替代方案。
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/netboot-a-fedora-live-cd/
+
+作者：[Gregory Bartholomew][a]
+选题：[lujun9972][b]
+译者：[robsean](https://github.com/robsean)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/glb/
+[b]: https://github.com/lujun9972
+[1]: https://en.wikipedia.org/wiki/Live_CD
+[2]: https://en.wikipedia.org/wiki/Live_CD#Uses
+[3]: https://en.wikipedia.org/wiki/ISCSI
+[4]: https://ipxe.org/
+[5]: https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/
+[6]: http://ipxe.org/cmd/sanboot/
+[7]: https://ipxe.org/appnote/buildtargets#boot_type
+[8]: https://en.wikipedia.org/wiki/Chain_loading
+[9]: https://www.syslinux.org/wiki/index.php?title=SYSLINUX
+[10]: https://en.wikipedia.org/wiki/EFI_system_partition
+[11]: https://docs.fedoraproject.org/en-US/quick-docs/creating-and-using-a-live-installation-image/#proc_creating-and-using-live-cd
+[12]: https://fedoramagazine.org/how-to-build-a-netboot-server-part-4/
+
diff --git a/published/20190322 Easy means easy to debug.md b/published/20190322 Easy means easy to debug.md
new file mode 100644
index 0000000000..8777acf660
--- /dev/null
+++ b/published/20190322 Easy means easy to debug.md
@@ -0,0 +1,79 @@
+[#]: collector: (lujun9972)
+[#]: translator: (LuuMing)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11693-1.html)
+[#]: subject: (Easy means easy to debug)
+[#]: via: (https://arp242.net/weblog/easy.html)
+[#]: author: (Martin Tournoij https://arp242.net/)
+
+简单就是易于调试
+======
+
+对于框架、库或者工具来说，怎样做才算是“简单”？也许有很多的定义，但我的理解通常是**易于调试**。我经常见到人们宣传某个特定的程序、框架、库、文件格式或者其它什么东西是简单的，因为他们会说“看，我只需要这么一点工作量就能够完成某项工作，这太简单了”。非常好，但并不完善。
+
+你可能只编写一次软件，但几乎总要经历好几个调试周期。注意我说的调试周期并不意味着“代码里面有 bug 你需要修复”，而是说“我需要再看一下这份代码来修复 bug”。为了调试代码，你需要理解它，因此“易于调试”延伸来讲就是“易于理解”。
+
+抽象使得程序易于编写，但往往是以难以理解为代价。有时候这是一个很好的折中，但通常不是。大体上，如果能使程序在日后易于理解和调试，我很乐意花更多的时间来写一些东西，因为这样实际上更省时间。
+
+简洁并不是让程序易于调试的**唯一**方法，但它也许是最重要的。良好的文档也是，但不幸的是好的文档太少了。（注意，质量并**不**取决于字数！）
+
+这种影响是真是存在的。难以调试的程序会有更多的 bug，即使最初的 bug 数量与易于调试的程序完全相同，而是因为修复 bug 更加困难、更花时间。
+
+在公司的环境中，把时间花在难以修复的 bug 上通常被认为是不划算的投资。而在开源的环境下，人们花的时间会更少。（大多数项目都有一个或多个定期的维护者，但成百上千的贡献者提交的仅只是几个补丁）
+
+---
+
+这并不全是 1974 年由 Brian W. Kernighan 和 P. J. Plauger 合著的《编程风格的元素》中的观点：
+
+> 每个人都知道调试比起编写程序困难两倍。当你写程序的时候耍小聪明，那么将来应该怎么去调试？
+
+我见过许多看起来写起来“极尽精妙”，但却导致难以调试的代码。我会在下面列出几种样例。争论这些东西本身有多坏并不是我的本意，我仅想强调对于“易于使用”和“易于调试”之间的折中。
+
+* ORM 库可以让数据库查询变得简单，代价是一旦你想解决某个问题，事情就变得难以理解。
+* 许多测试框架让调试变得困难。Ruby 的 rspec 就是一个很好的例子。有一次我不小心使用错了，结果花了很长时间搞清楚**究竟**哪里出了问题（因为它给出错误提示非常含糊）。
+
+ 我在《[测试并非万能][1]》这篇文章中写了更多关于以上的例子。
+* 我用过的许多 JavaScript 框架都很难完全理解。Clever（LCTT 译注：一种 JS 框架）的语句一向很有逻辑，直到某条语句不能如你预期的工作，这时你就只能指望 Stack Overflow 上的某篇文章或 GitHub 上的某个回帖来帮助你了。
+
+ 这些函数库**确实**让任务变得非常简单，使用它们也没有什么错。但通常人们都过于关注“易于使用”而忽视了“易于调试”这一点。
+* Docker 非常棒，并且让许多事情变得非常简单，直到你看到了这条提示：
+
+ ```
+ ERROR: for elasticsearch Cannot start service elasticsearch:
+oci runtime error: container_linux.go:247: starting container process caused "process_linux.go:258:
+applying cgroup configuration for process caused \"failed to write 898 to cgroup.procs: write
+/sys/fs/cgroup/cpu,cpuacct/docker/b13312efc203e518e3864fc3f9d00b4561168ebd4d9aad590cc56da610b8dd0e/cgroup.procs:
+invalid argument\""
+```
+
+ 或者这条：
+
+ ```
+ERROR: for elasticsearch Cannot start service elasticsearch: EOF
+```
+
+ 那么...你怎么看？
+* `Systemd` 比起 `SysV`、`init.d` 脚本更加简单，因为编写 `systemd` 单元文件比起编写 `shell` 脚本更加方便。这也是 Lennart Poetterin 在他的 [systemd 神话][2] 中解释 `systemd` 为何简单时使用的论点。
+
+ 我非常赞同 Poettering 的观点——也可以看 [shell 脚本陷阱][3] 这篇文章。但是这种角度并不全面。单元文件简单的背后意味着 `systemd` 作为一个整体要复杂的多，并且用户确实会受到它的影响。看看我遇到的这个[问题][4]和为它所做的[修复][5]。看起来很简单吗？
+
+
+--------------------------------------------------------------------------------
+
+via: https://arp242.net/weblog/easy.html
+
+作者：[Martin Tournoij][a]
+选题：[lujun9972][b]
+译者：[LuuMing](https://github.com/LuuMing)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://arp242.net/
+[b]: https://github.com/lujun9972
+[1]: https://www.arp242.net/testing.html
+[2]: http://0pointer.de/blog/projects/the-biggest-myths.html
+[3]:https://www.arp242.net/shell-scripting-trap.html
+[4]:https://unix.stackexchange.com/q/185495/33645
+[5]:https://cgit.freedesktop.org/systemd/systemd/commit/?id=6e392c9c45643d106673c6643ac8bf4e65da13c1
diff --git a/published/20190513 How To Set Password Complexity On Linux.md b/published/20190513 How To Set Password Complexity On Linux.md
new file mode 100644
index 0000000000..f9dfca1e8e
--- /dev/null
+++ b/published/20190513 How To Set Password Complexity On Linux.md
@@ -0,0 +1,186 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11709-1.html)
+[#]: subject: (How To Set Password Complexity On Linux?)
+[#]: via: (https://www.2daygeek.com/how-to-set-password-complexity-policy-on-linux/)
+[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
+
+Linux 如何设置密码复杂度？
+======
+
+对于 Linux 系统管理员来说，用户管理是最重要的事之一。这涉及到很多因素，实现强密码策略是用户管理的其中一个方面。移步后面的 URL 查看如何 [在 Linux 上生成一个强密码][1]。它会限制系统未授权的用户的访问。
+
+所有人都知道 Linux 的默认策略很安全，然而我们还是要做一些微调，这样才更安全。弱密码有安全隐患，因此，请特别注意。移步后面的 URL 查看生成的强密码的[密码长度和分值][2]。本文将教你在 Linux 中如何实现最安全的策略。
+
+在大多数 Linux 系统中，我们可以用 PAM（可插拔认证模块）来加强密码策略。在下面的路径可以找到这个文件。
+
+- 在红帽系列的系统中，路径：`/etc/pam.d/system-auth`。
+- Debian 系列的系统中，路径：`/etc/pam.d/common-password`。
+
+关于默认的密码过期时间，可以在 `/etc/login.defs` 文件中查看详细信息。
+
+为了更好理解，我摘取了文件的部分内容：
+
+```
+# vi /etc/login.defs
+
+PASS_MAX_DAYS 99999
+PASS_MIN_DAYS 0
+PASS_MIN_LEN 5
+PASS_WARN_AGE 7
+```
+
+详细解释:
+
+* `PASS_MAX_DAYS`：一个密码可使用的最大天数。
+* `PASS_MIN_DAYS`：两次密码修改之间最小的间隔天数。
+* `PASS_MIN_LEN`：密码最小长度。
+* `PASS_WARN_AGE`：密码过期前给出警告的天数。
+
+我们将会展示在 Linux 中如何实现下面的 11 个密码策略。
+
+* 一个密码可使用的最大天数
+* 两次密码修改之间最小的间隔天数
+* 密码过期前给出警告的天数
+* 密码历史记录/拒绝重复使用密码
+* 密码最小长度
+* 最少的大写字母个数
+* 最少的小写字母个数
+* 最少的数字个数
+* 最少的其他字符（符号）个数
+* 账号锁定 — 重试
+* 账号解锁时间
+
+### 密码可使用的最大天数是什么？
+
+这一参数限制一个密码可使用的最大天数。它强制用户在过期前修改他/她的密码。如果他们忘记修改，那么他们会登录不了系统。他们需要联系管理员才能正常登录。这个参数可以在 `/etc/login.defs` 文件中设置。我把这个参数设置为 90 天。
+
+```
+# vi /etc/login.defs
+
+PASS_MAX_DAYS 90
+```
+
+### 密码最小天数是什么？
+
+这个参数限制两次修改之间的最少天数。举例来说，如果这个参数被设置为 15 天，用户今天修改了密码，那么在 15 天之内他都不能修改密码。这个参数可以在 `/etc/login.defs` 文件中设置。我设置为 15 天。
+
+```
+# vi /etc/login.defs
+
+PASS_MIN_DAYS 15
+```
+
+### 密码警告天数是什么？
+
+这个参数控制密码警告的前置天数，在密码即将过期时会给用户警告提示。在警告天数结束前，用户会收到日常警告提示。这可以提醒用户在密码过期前修改他们的密码，否则我们就需要联系管理员来解锁密码。这个参数可以在 `/etc/login.defs` 文件中设置。我设置为 10 天。
+
+```
+# vi /etc/login.defs
+
+PASS_WARN_AGE 10
+```
+
+**注意:** 上面的所有参数仅对新账号有效，对已存在的账号无效。
+
+### 密码历史或拒绝重复使用密码是什么？
+
+这个参数控制密码历史。它记录曾经使用过的密码（禁止使用的曾用密码的个数）。当用户设置新的密码时，它会检查密码历史，如果他们要设置的密码是一个曾经使用过的旧密码，将会发出警告提示。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。我设置密码历史为 5。
+
+```
+# vi /etc/pam.d/system-auth
+
+password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok remember=5
+```
+
+### 密码最小长度是什么？
+
+这个参数表示密码的最小长度。当用户设置新密码时，系统会检查这个参数，如果新设的密码长度小于这个参数设置的值，会收到警告提示。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。我设置最小密码长度为 12。
+
+```
+# vi /etc/pam.d/system-auth
+
+password requisite pam_cracklib.so try_first_pass retry=3 minlen=12
+```
+
+`try_first_pass retry=3`：在密码设置交互界面，用户有 3 次机会重设密码。
+
+### 设置最少的大写字母个数？
+
+这个参数表示密码中至少需要的大写字母的个数。这些是密码强度参数，可以让密码更健壮。当用户设置新密码时，系统会检查这个参数，如果密码中没有大写字母，会收到警告提示。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。我设置密码（中的大写字母）的最小长度为 1 个字母。
+
+```
+# vi /etc/pam.d/system-auth
+
+password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 ucredit=-1
+```
+
+### 设置最少的小写字母个数？
+
+这个参数表示密码中至少需要的小写字母的个数。这些是密码强度参数，可以让密码更健壮。当用户设置新密码时，系统会检查这个参数，如果密码中没有小写字母，会收到警告提示。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。我设置为 1 个字母。
+
+```
+# vi /etc/pam.d/system-auth
+
+password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 lcredit=-1
+```
+
+### 设置密码中最少的数字个数？
+
+这个参数表示密码中至少需要的数字的个数。这些是密码强度参数，可以让密码更健壮。当用户设置新密码时，系统会检查这个参数，如果密码中没有数字，会收到警告提示。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。我设置为 1 个数字。
+
+```
+# vi /etc/pam.d/system-auth
+
+password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 dcredit=-1
+```
+
+### 设置密码中最少的其他字符（符号）个数？
+
+这个参数表示密码中至少需要的特殊符号的个数。这些是密码强度参数，可以让密码更健壮。当用户设置新密码时，系统会检查这个参数，如果密码中没有特殊符号，会收到警告提示。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。我设置为 1 个字符。
+
+```
+# vi /etc/pam.d/system-auth
+
+password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 ocredit=-1
+```
+
+### 设置账号锁定？
+
+这个参数控制用户连续登录失败的最大次数。当达到设定的连续失败登录次数阈值时，锁定账号。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。
+
+```
+# vi /etc/pam.d/system-auth
+
+auth required pam_tally2.so onerr=fail audit silent deny=5
+account required pam_tally2.so
+```
+
+### 设定账号解锁时间？
+
+这个参数表示用户解锁时间。如果一个用户账号在连续认证失败后被锁定了，当过了设定的解锁时间后，才会解锁。设置被锁定中的账号的解锁时间（900 秒 = 15分钟）。这个参数可以在 `/etc/pam.d/system-auth` 文件中设置。
+
+```
+# vi /etc/pam.d/system-auth
+
+auth required pam_tally2.so onerr=fail audit silent deny=5 unlock_time=900
+account required pam_tally2.so
+```
+
+--------------------------------------------------------------------------------
+
+via: https://www.2daygeek.com/how-to-set-password-complexity-policy-on-linux/
+
+作者：[Magesh Maruthamuthu][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.2daygeek.com/author/magesh/
+[b]: https://github.com/lujun9972
+[1]: https://www.2daygeek.com/5-ways-to-generate-a-random-strong-password-in-linux-terminal/
+[2]: https://www.2daygeek.com/how-to-check-password-complexity-strength-and-score-in-linux/
diff --git a/published/20190711 DevOps for introverted people.md b/published/20190711 DevOps for introverted people.md
new file mode 100644
index 0000000000..e18b27da4f
--- /dev/null
+++ b/published/20190711 DevOps for introverted people.md
@@ -0,0 +1,73 @@
+[#]: collector: (lujun9972)
+[#]: translator: (XLCYun)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11725-1.html)
+[#]: subject: (DevOps for introverted people)
+[#]: via: (https://opensource.com/article/19/7/devops-introverted-people)
+[#]: author: (Matthew Broberg https://opensource.com/users/mbbroberg)
+
+内向者的 DevOps
+======
+
+> 我们邀请 Opensource.com 的 DevOps 团队，希望他们能够谈一谈作为 DevOps 内向者的休验，同时给 DevOps 外向者一些建议。下面是他们的回答。
+
+
+
+我们邀请我们的 [DevOps 团队][2] 谈一谈他们作为一个内向者的体验，并给外向者们一些建议。但是在我们开始了解他们的回答之前，让我们先来定义一下这些词汇。
+
+### “内向者”是什么意思？
+
+内向者通常指的是一部分人群，当他们和别人相处的时候，会使他们的能量耗尽，而不是激发他们更多的能量。当我们思考我们是如何恢复能量时，这是一个非常有用的词汇：内向者通常需要更多的独处时间来恢复能量，特别是和一群人在一起很长时间后。关于内向者的一个非常大的误解就是他们一定是“害羞的”，但是科学表明，那不过是另一种不同的性格特征。
+
+内向性与外向性是通过 [Myers Briggs 类型指标][4] 而为人所知的，现在也常常被称作一个 [光谱][5] 的两端。虽然这个世界看起来好像外向者比内向者要多，但是心理学者则倾向于认为大部分人在光谱上的位置是落在 [中间性格或偏内向性格的][6]。
+
+现在，我们来看看问答。
+
+### DevOps 技术主管可以通过哪些方式来让内向者感觉他们是团队的一部分并且愿意分享他们的想法？
+
+“每个人都会不大一样，所以观察敏锐就很重要了。从 GitLab 过来的一个人告诉我，他们的哲学就是如果他们没有提供任何意见，那么他们就是被排除在外的。如果有人在一个会议上没有提供任何的意见，那就想办法让他们加入进来。**当我知道一个内向者对我们将要讨论的会议论题感兴趣的时候，我会提前请他写一些书面文本。有非常多的会议其实是可以避免的，只要通过把讨论放到 Slack 或者 GitLab 上就行了，内向者会更愿意参与进来**。在站立会议中，每个人都会交代最新的进展，在这个环境下，内向者表现得很好。有时候我们在其实会议上会重复做一些事情，仅仅是为了保证每个人都有时间发言。我同时也会鼓励内向者在工作小组或者社区小组面前发言，以此来锻炼他们的这些技能。”—— 丹·巴克
+
+“**我觉得别人对我做的最好的事情，就是他们保证了当重大问题来临的时候，我拥有必要的技能去回答它**。彼时，我作为一名非常年轻的入伍空军的一员，我需要给我们部队的高级领导做状态简报的汇报。我必须在任何时候都有一些可用的数据点，以及在实现我们确立的目标的过程中，产生延误以及偏差的背后的原因。那样的经历推动着我从一个‘幕后人员’逐渐变得更加愿意和别人分享自己的观点和想法。”—— 克里斯·肖特
+
+“**通过文化去领导。为你的同僚一起设计和尝试仪式。**你可以为给你的小组或团队设计一个小的每周仪式，甚至给你的部门或组织设计一个年度的大仪式。它的意义在于去尝试一些事物，并观察你在其中的领导角色。去找到你们文化当中的代沟以及对立。回顾团队的信仰和行为。你能从哪里观察到对立？你们的文化中缺失了什么？从一个小陈述开始‘我从 X 和 Y 之间看到了对立’，或者‘我的团队缺少了 Z’。接着，将代沟与对立转换为问题：写下三个‘我们如何能……(How might we's, HMWs)’。”—— 凯瑟琳·路易斯
+
+“内向者不是一个不同的群体，他们要么是在分享他们的想法之前想得太多或等得太久的一些人，要么就是一些根本不知道发生了什么的人。我就是第一种，我想太多了，有时候还担心我的意见会被其他人嘲笑，或者没有什么意思，或者想偏了。形成那样的思维方式很难，但它同时也在吞噬着我学习更好事物的机会。有一次，我们团队在讨论一个实现问题。我当时的老大一次又一次地问我，为什么我没有作为团队中更具经验的人参与进来，然后我就（集齐了全宇宙的力量之后）开口说我想说的大家都已经说过了。他说，有时候我可以重复说一次，事情纷繁，如果你能够重复一遍你的想法，即使它已经被讨论过了，也会大有裨益。好吧，虽然它不是一种特别信服的方式，但是我知道了至少有人想听听我怎么说，它给了我一点信心。
+
+“现在，我所使用的让团队中的人发言的方法是**我经常向内向的人求助，即使我知道解决方法，并且在团队会议和讨论中感谢他们来建立他们的自信心，通过给他们时间让他们一点一点的从他们寡言的本性中走出来，从而跟团队分享很多的知识**。他们在外面的世界中可能仍然会有一点点孤立，但是在团队里面，有些会成为我们可以信赖的人。”—— 阿布希什克·塔姆拉卡尔
+
+“我给参加会议的内向者的建议是，找一个同样要参加会议的朋友或者同事，这样到时你就会有人可以跟你一起舒服地交谈，在会议开始之前，提前跟其他的与会者（朋友、行业联系人、前同事等等）约着见个面或者吃顿饭，**要注意你的疲劳程度，并且照顾好自己**：如果你需要重新恢复能量，就跳过那些社交或者夜晚的活动，在事后回顾中记录一下自己的感受。”—— 伊丽莎白·约瑟夫
+
+### 和一个内向者倾向的同事一起工作时，有什么提高生产效率的小建议？
+
+“在保证质量时，生产效率会越来越具备挑战性。在大多数时候，工作中的一个小憩或者轻松随意的交谈，可能正是我们的创造性活动中需要的一个火花。再说一次，我发现当你的团队中有内向者时， Slack 和 Github 会是一个非常有用的用于交换想法以及和其他人互动的媒介。**我同时也发现，结对编程对于大部分的内向者也非常有用，虽然一对一的交流对于他们来说，并不像交税那么频繁，但是生产质量和效率的提升却是重大的**。但是，当一个内向者在独自工作的时间，团队中的所有人都不应该去打断他们。最好是发个邮件，或者使用没有那么强的侵入性的媒介。”—— 丹·巴克
+
+“给他们趁手的工具，让他们工作并归档他们的工作。**让他们能够在他们的工作上做到最好**。要足够经常地去检查一下，保证他们没有走偏路，但是要记住，相比外向者而言，这样做是更大的一种让人分心的困扰。”—— 克里斯·肖特
+
+“**当我低着头的时候，不要打断我。真的，别打断我！**当我沉浸在某件事物中时，这样做会造成我至少需要花费两个小时，才能让我的大脑重新回到之前的状态。感觉很痛苦。真的。你可以发个邮件让我去有白板的地方。然后从客户的角度而不是你的角度——通过画图的方式——分享下有什么问题。要知道，可能同时会有十几个客户问题缠绕在我的脑海中，如果你的问题听起来就是‘这样子做会让我在我的领导面前显得很好’的那一类问题，那么相比我脑袋中已经有的真正的客户问题而言，它不会得到更多的关注的。画个图，给我点时间思考。当我准备分享我的看法的时候，保证有多支马克笔可以使用。准备好接受你对问题的假设有可能完全是错误的。”—— 凯瑟琳·路易斯
+
+“感谢和鼓励就是解决的方法，感谢可能不是一份工作评估，但是感谢能让人舒服地感受到自己并不仅仅是一个活着的独立实体，**因而每个人都能够感觉到自己是被倾听的，而不是被嘲笑或者低估的**。”—— 阿布希什克·塔姆拉卡尔
+
+### 结语
+
+在与内向的 DevOps 爱好者的这次交谈中，我们最大的启迪就是平等：其他人需要被怎样对待，就怎样对待他们，同时你想被怎样对待，就去要求别人怎样对待你。无论你是内向还是外向，我们都需要承认我们并非全以相同的一种方式体验这个世界。我们的同事应当被给予足够的空间以完成他们的工作，通过讨论他们的需求作为了解如何支持他们的开始。我们的差异正是我们的社区如此特别的原因，它让我们的工作对更多的人更加的有用。与别人沟通最有效的方式，就是对于你们两者而言都可行的方式。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/7/devops-introverted-people
+
+作者：[Matthew Broberg][a]
+选题：[lujun9972][b]
+译者：[XLCYun](https://github.com/XLCYun)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/mbbroberg
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc_QandAorange_520x292_0311LL.png?itok=qa3hHSou (Q and A letters)
+[2]: https://opensource.com/devops-team
+[3]: https://www.inc.com/melanie-curtin/are-you-shy-or-introverted-science-says-this-is-1-primary-difference.html
+[4]: https://www.myersbriggs.org/my-mbti-personality-type/mbti-basics/extraversion-or-introversion.htm?bhcp=1
+[5]: https://lifehacker.com/lets-quit-it-with-the-introvert-extrovert-nonsense-1713772952
+[6]: https://www.psychologytoday.com/us/blog/the-gen-y-guide/201710/the-majority-people-are-not-introverts-or-extroverts
diff --git a/published/20190725 24 sysadmin job interview questions you should know.md b/published/20190725 24 sysadmin job interview questions you should know.md
new file mode 100644
index 0000000000..b2b6f9b812
--- /dev/null
+++ b/published/20190725 24 sysadmin job interview questions you should know.md
@@ -0,0 +1,235 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11673-1.html)
+[#]: subject: (24 sysadmin job interview questions you should know)
+[#]: via: (https://opensource.com/article/19/7/sysadmin-job-interview-questions)
+[#]: author: (DirectedSoul https://opensource.com/users/directedsoul)
+
+24 个必知必会的系统管理员面试问题
+======
+
+> 即将进行系统管理员工作面试吗？阅读本文，了解你可能会遇到的一些问题以及可能的答案。
+
+
+
+作为一个经常与计算机打交道的极客，在硕士毕业后在 IT 行业选择我的职业是很自然的选择。因此，我认为走上系统管理员之路是正确的路径。在我的职业生涯中，我对求职面试过程非常熟悉。现在来看一下对该职位的预期、职业发展道路，以及一系列常见面试问题及我的回答。
+
+### 系统管理员的典型任务和职责
+
+组织需要了解系统工作原理的人员，以确保数据安全并保持服务平稳运行。你可能会问：“等等，是不是系统管理员还能做更多的事情？”
+
+你是对的。现在，一般来说，让我们看一下典型的系统管理员的日常任务。根据公司的需求和人员的技能水平，系统管理员的任务从管理台式机、笔记本电脑、网络和服务器到设计组织的 IT 策略不等。有时，系统管理员甚至负责购买和订购新的 IT 设备。
+
+那些寻求系统管理工作以作为其职业发展道路的人可能会发现，由于 IT 领域的快速变化是不可避免的，因此难以保持其技能和知识的最新状态。所有人都会想到的下一个自然而然的问题是 IT 专业人员如何掌握最新的更新和技能。
+
+### 简单的问题
+
+这是你将遇到的一些最基本的问题，以及我的答案：
+
+**1、你在 \*nix 服务器上登录后键入的前五个命令是什么？**
+
+> * `lsblk` 以查看所有的块设备信息
+> * `who` 查看谁登录到服务器
+> * `top`，以了解服务器上正在运行的进程
+> * `df -khT` 以查看服务器上可用的磁盘容量
+> * `netstat` 以查看哪些 TCP 网络连接处于活动状态
+
+**2、如何使进程在后台运行，这样做的好处是什么？**
+
+> 你可以通过在命令末尾添加特殊字符 `＆` 来使进程在后台运行。通常，执行时间太长并且不需要用户交互的应用程序可以放到后台，以便我们可以在终端中继续工作。（[引文][2]）
+
+**3、以 root 用户身份运行这些命令是好事还是坏事？**
+
+> 由于两个主要问题，以 root 身份运行（任何命令）是不好的。第一个是*风险*。当你以 **root** 身份登录时，无法避免你由于粗心大意而犯错。如果你尝试以带有潜在危害的方式更改系统，则需要使用 `sudo`，它会引入一个暂停（在你输入密码时），以确保你不会犯错。
+>
+> 第二个原因是*安全*。如果你不知道管理员用户的登录信息，则系统更难被攻击。拥有 root 的访问权限意味着你已经能够进行管理员身份下的一半工作任务。
+
+**4、`rm` 和 `rm -rf` 有什么区别？**
+
+> `rm` 命令本身仅删除指明的文件（而不删除目录）。使用 `-rf` 标志，你添加了两个附加功能：`-r`（或等价的 `-R`、`--recursive`）标志可以递归删除目录的内容，包括隐藏的文件和子目录；而 `-f`（或 `--force`）标志使 `rm` 忽略不存在的文件，并且从不提示你进行确认。
+
+**5、有一个大小约为 15GB 的 `Compress.tgz` 文件。你如何列出其内容，以及如何仅提取出特定文件？**
+
+> 要列出文件的内容：
+>
+> `tar tf archive.tgz`
+>
+> 要提取特定文件：
+>
+> `tar xf archive.tgz filename`
+
+### 有点难度的问题
+
+这是你可能会遇到的一些较难的问题，以及我的答案：
+
+**6、什么是 RAID？什么是 RAID 0、RAID 1、RAID 5、RAID 6 和 RAID 10？**
+
+> RAID（廉价磁盘冗余阵列）是一种用于提高数据存储性能和/或可靠性的技术。RAID 级别为：
+>
+> * RAID 0：也称为磁盘条带化，这是一种分解文件并将数据分布在 RAID 组中所有磁盘驱动器上的技术。它没有防止磁盘失败的保障。（[引文][3]）
+> * RAID 1：一种流行的磁盘子系统，通过在两个驱动器上写入相同的数据来提高安全性。RAID 1 被称为*镜像*，它不会提高写入性能，但读取性能可能会提高到每个磁盘性能的总和。另外，如果一个驱动器发生故障，则会使用第二个驱动器，发生故障的驱动器需要手动更换。更换后，RAID 控制器会将可工作的驱动器的内容复制到新驱动器上。
+> * RAID 5：一种磁盘子系统，可通过计算奇偶校验数据来提高安全性和提高速度。RAID 5 通过跨三个或更多驱动器交错数据（条带化）来实现此目的。在单个驱动器发生故障时，后续读取可以从分布式奇偶校验计算出，从而不会丢失任何数据。
+> * RAID 6：通过添加另一个奇偶校验块来扩展 RAID 5。此级别至少需要四个磁盘，并且可以在任何两个并发磁盘故障的情况下继续执行读/写操作。RAID 6 不会对读取操作造成性能损失，但由于与奇偶校验计算相关的开销，因此确实会对写入操作造成性能损失。
+> * RAID 10：RAID 10 也称为 RAID 1 + 0，它结合了磁盘镜像和磁盘条带化功能来保护数据。它至少需要四个磁盘，并且跨镜像对对数据进行条带化。只要每个镜像对中的一个磁盘起作用，就可以检索数据。如果同一镜像对中的两个磁盘发生故障，则所有数据将丢失，因为带区集中没有奇偶校验。（[引文][4]）
+
+**7、`ping` 命令使用哪个端口？**
+
+> `ping` 命令使用 ICMP。具体来说，它使用 ICMP 回显请求和应答包。
+>
+> ICMP 不使用 UDP 或 TCP 通信服务：相反，它使用原始的 IP 通信服务。这意味着，ICMP 消息直接承载在 IP 数据报数据字段中。
+
+**8、路由器和网关之间有什么区别？什么是默认网关？**
+
+> *路由器*描述的是一种通用技术功能（第 3 层转发）或用于该目的的硬件设备，而*网关*描述的是本地网段的功能（提供到其他地方的连接性）。你还可以说“将路由器设置为网关”。另一个术语是“跳”，它描述了子网之间的转发。
+>
+> 术语*默认网关*表示局域网上的路由器，它的责任是作为对局域网外部的计算机通信的第一个联系点。
+
+**9、解释一下 Linux 的引导过程。**
+
+> BIOS -> 主引导记录（MBR） -> GRUB -> 内核 -> 初始化 -> 运行级
+
+**10、服务器启动时如何检查错误消息？**
+
+> 内核消息始终存储在 kmsg 缓冲区中，可通过 `dmesg` 命令查看。
+>
+> 引导出现的问题和错误要求系统管理员结合某些特定命令来查看某些重要文件，这些文件不同版本的 Linux 处理方式不同：
+>
+> * `/var/log/boot.log` 是系统引导日志，其中包含系统引导过程中展开的所有内容。
+> * `/var/log/messages` 存储全局系统消息，包括系统引导期间记录的消息。
+> * `/var/log/dmesg` 包含内核环形缓冲区信息。
+
+**11、符号链接和硬链接有什么区别？**
+
+> *符号链接*（*软链接*）实际是到原始文件的链接，而*硬链接*是原始文件的镜像副本。如果删除原始文件，则该软链接就没有用了，因为它指向的文件不存在了。如果是硬链接，则完全相反。如果删除原始文件，则硬链接仍然包含原始文件中的数据。（[引文][5]）
+
+**12、如何更改内核参数？你可能需要调整哪些内核选项？**
+
+> 要在类 Unix 系统中设置内核参数，请首先编辑文件 `/etc/sysctl.conf`。进行更改后，保存文件并运行 `sysctl -p` 命令。此命令使更改永久生效，而无需重新启动计算机
+
+**13、解释一下 `/proc` 文件系统。**
+
+> `/proc` 文件系统是虚拟的，并提供有关内核、硬件和正在运行的进程的详细信息。由于 `/proc` 包含虚拟文件，因此称为“虚拟文件系统”。这些虚拟文件具有独特性。其中大多数显示为零字节。
+>
+> 虚拟文件，例如 `/proc/interrupts`、`/proc/meminfo`、`/proc/mounts` 和 `/proc/partitions`，提供了系统硬件的最新信息。其他诸如 `/proc/filesystems` 和 `/proc/sys` 目录提供系统配置信息和接口。
+
+**14、如何在没有密码的情况下以其他用户身份运行脚本？**
+
+> 例如，如果你可以编辑 sudoers 文件（例如 `/private/etc/sudoers`），则可以使用 `visudo` 添加以下[内容][2]：
+>
+> `user1 ALL =（user2）NOPASSWD：/opt/scripts/bin/generate.sh`
+
+**15、什么是 UID 0 toor 帐户？是被入侵了么？**
+
+> `toor` 用户是备用的超级用户帐户，其中 `toor` 是 `root` 反向拼写。它预期与非标准 shell 一起使用，因此 `root` 的默认 shell 不需要更改。
+>
+> 此用途很重要。这些 shell 不是基本发行版的一部分，而是从 ports 或软件包安装的，它们安装在 `/usr/local/bin` 中，默认情况下，位于其他文件系统上。如果 root 的 shell 位于 `/usr/local/bin` 中，并且未挂载包含 `/usr/local/bin` 的文件系统，则 root 无法登录以解决问题，并且系统管理员必须重新启动进入单用户模式来输入 shell 程序的路径。
+
+### 更难的问题
+
+这是你可能会遇到的甚至更困难的问题：
+
+**16、`tracert` 如何工作，使用什么协议？**
+
+> 命令 `tracert`（或 `traceroute`，具体取决于操作系统）使你可以准确地看到在连接到最终目的地的连接链条中所触及的路由器。如果你遇到无法连接或无法 `ping` 通最终目的地的问题，则可以使用 `tracert` 来帮助你确定连接链在何处停止。（[引文][6]）
+>
+> 通过此信息，你可以联系正确的人；无论是你自己的防火墙、ISP、目的地的 ISP 还是中间的某个位置。 `tracert` 命令像 `ping` 一样使用 ICMP 协议，但也可以使用 TCP 三步握手的第一步来发送 SYN 请求以进行响应。
+
+**17、使用 `chroot` 的主要优点是什么？我们何时以及为什么使用它？在 chroot 环境中，`mount /dev`、`mount /proc` 和 `mount /sys` 命令的作用是什么？**
+
+> chroot 环境的优点是文件系统与物理主机是隔离的，因为 chroot 在文件系统内部有一个单独的文件系统。区别在于 `chroot` 使用新创建的根目录（`/`）作为其根目录。
+>
+> chroot 监狱可让你将进程及其子进程与系统其余部分隔离。它仅应用于不以 root 身份运行的进程，因为 root 用户可以轻松地脱离监狱。
+>
+> 该思路是创建一个目录树，在其中复制或链接运行该进程所需的所有系统文件。然后，你可以使用 `chroot()` 系统调用来告诉它根目录现在位于此新树的基点上，然后启动在该 chroot 环境中运行的进程。由于该命令因此而无法引用修改后的根目录之外的路径，因此它无法在这些位置上执行恶意操作（读取、写入等）。（[引文][7]）
+
+**18、如何保护你的系统免遭黑客攻击？**
+
+> 遵循最低特权原则和这些做法：
+>
+> * 使用公钥加密，它可提供出色的安全性。
+> * 增强密码复杂性。
+> * 了解为什么要对上述规则设置例外。
+> * 定期检查你的例外情况。
+> * 让具体的人对失败负责。（它使你保持警惕。）（[引文][8]）
+
+**19、什么是 LVM，使用 LVM 有什么好处？**
+
+> LVM（逻辑卷管理）是一种存储设备管理技术，该技术使用户能够合并和抽象化组件存储设备的物理布局，从而可以更轻松、灵活地进行管理。使用设备映射器的 Linux 内核框架，当前迭代（LVM2）可用于将现有存储设备收集到组中，并根据需要从组合的空间分配逻辑单元。
+
+**20、什么是粘性端口？**
+
+> 粘性端口是网络管理员最好的朋友，也是最头痛的事情之一。它们允许你设置网络，以便通过将交换机上的每个端口锁定到特定的 MAC 地址，仅允许一台（或你指定的数字）计算机在该端口上进行连接。
+
+**21、解释一下端口转发？**
+
+> 尝试与安全的网络内部的系统进行通信时，从外部进行通信可能非常困难，这是很显然的。因此，在路由器本身或其他连接管理设备中使用端口转发表可以使特定流量自动转发到特定目的地。例如，如果你的网络上运行着一台 Web 服务器，并且想从外部授予对该服务器的访问权限，则可以将端口转发设置为该服务器上的端口 80。这意味着在 Web 浏览器中输入你的（外网）IP 地址的任何人都将立即连接到该服务器的网站。
+>
+> 请注意，通常不建议允许从你的网络外部直接访问服务器。
+
+**22、对于 IDS，误报和漏报是什么？**
+
+> 当入侵检测系统（IDS）设备为实际上没有发生的入侵生成警报时，这是误报（假阳性）。如果设备未生成任何警报，而入侵实际上已发生，则为漏报（假阴性）。
+
+**23、解释一下 `:(){ :|:& };:`，如果已经登录系统，如何停止此代码？**
+
+> 这是一枚复刻炸弹。它分解如下：
+>
+> * `:()` 定义了函数，以 `:` 作为函数名，并且空括号表示它不接受任何参数。
+> * `{}` 是函数定义的开始和结束。
+> * `:|:` 将函数 `:` 的副本加载到内存中，并将其输出通过管道传递给函数 `:` 的另一个副本，该副本也必须加载到内存中。
+> * `＆` 使前一个命令行成为后台进程，因此即使父进程被自动杀死，子进程也不会被杀死。
+> * `:` 执行该函数，因此连锁反应开始。
+>
+> 保护多用户系统的最佳方法是使用特权访问管理（PAM）来限制用户可以使用的进程数。
+>
+> 复刻炸弹的最大问题是它发起了太多进程。因此，如果你已经登录系统，我们有两种尝试解决此问题的方法。一种选择是执行一个 `SIGSTOP` 命令来停止进程，例如：
+>
+> `killall -STOP -u user1`
+>
+> 如果由于占用了所有进程而无法使用命令行，则必须使用 `exec` 强制其运行：
+>
+> `exec killall -STOP -u user1`
+>
+> 对于复刻炸弹，最好的选择是防患于未然。
+
+**24、什么是 OOM 杀手，它如何决定首先杀死哪个进程？**
+
+> 如果内存被进程彻底耗尽，可能会威胁到系统的稳定性，那么内存不足（OOM）杀手就登场了。
+>
+> OOM 杀手首先必须选择要杀死的最佳进程。*最佳*在这里指的是在被杀死时将释放最大内存的进程，并且对系统来说最不重要。主要目标是杀死最少数量的进程，以最大程度地减少造成的损害，同时最大化释放的内存量。
+>
+> 为了实现此目标，内核为每个进程维护一个 `oom_score`。你可以在 `/proc` 文件系统中的 `pid` 目录下的看到每个进程的 `oom_score`：
+>
+> `$ cat /proc/10292/oom_score`
+>
+> 任何进程的 `oom_score` 值越高，在内存不足的情况下被 OOM 杀手杀死的可能性就越高。（[引文][9]）
+
+### 总结
+
+系统管理人员的薪水[差别很大][10]，有些网站上说年薪在 70,000 到 100,000 美元之间，具体取决于地点、组织的规模以及你的教育水平以及多年的工作经验。系统管理的职业道路最终归结为你对使用服务器和解决那些酷问题的兴趣。现在，我要说，继续前进，实现你的梦想之路吧！
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/7/sysadmin-job-interview-questions
+
+作者：[DirectedSoul][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/directedsoul
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_HowToFish_520x292.png?itok=DHbdxv6H (Question and answer.)
+[2]: https://github.com/trimstray/test-your-sysadmin-skills
+[3]: https://www.waytoeasylearn.com/2016/05/netapp-filer-tutorial.html
+[4]: https://searchstorage.techtarget.com/definition/RAID-10-redundant-array-of-independent-disks
+[5]: https://www.answers.com/Q/What_is_hard_link_and_soft_link_in_Linux
+[6]: https://www.wisdomjobs.com/e-university/network-administrator-interview-questions.html
+[7]: https://unix.stackexchange.com/questions/105/chroot-jail-what-is-it-and-how-do-i-use-it
+[8]: https://serverfault.com/questions/391370/how-to-prevent-zero-day-attacks
+[9]: https://unix.stackexchange.com/a/153586/8369
+[10]: https://blog.netwrix.com/2018/07/23/systems-administrator-salary-in-2018-how-much-can-you-earn/
diff --git a/published/20191004 What-s in an open source name.md b/published/20191004 What-s in an open source name.md
new file mode 100644
index 0000000000..2b6d45c599
--- /dev/null
+++ b/published/20191004 What-s in an open source name.md
@@ -0,0 +1,200 @@
+[#]: collector: (lujun9972)
+[#]: translator: (laingke)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11688-1.html)
+[#]: subject: (What's in an open source name?)
+[#]: via: (https://opensource.com/article/19/10/open-source-name-origins)
+[#]: author: (Joshua Allen Holm https://opensource.com/users/holmja)
+
+开源软件名称中的故事
+======
+
+> 有没有想过你喜欢的开源项目或编程语言的名称来自何处？让我们按字母顺序了解一下流行的技术术语背后的起源故事。
+
+
+
+GNOME、Java、Jupyter、Python……如果你的朋友或家人曾留意过你的工作对话，他们可能会认为你从事文艺复兴时期的民间文学艺术、咖啡烘焙、天文学或动物学工作。这些开源技术的名称从何而来？我们请我们的作者社区提供意见，并汇总了一些我们最喜欢的技术名称的起源故事。
+
+### Ansible
+
+“Ansible”这个名称直接来自科幻小说。Ursula Le Guin 的《Rocannon's World》一书中能进行即时（比光速更快）通信的设备被称为 ansibles（显然来自 “answerable” 一词）。Ansibles 开始流行于科幻小说之中，Orson Scott Card 的《Ender's Game》（后来成为受欢迎的电影）中，该设备控制了许多远程太空飞船。对于控制分布式机器的软件来说，这似乎是一个很好的模型，因此 Michael DeHaan（Ansible 的创建者和创始人）借用了这个名称。
+
+### Apache
+
+[Apache][2] 是最初于 1995 年发布的开源 Web 服务器。它的名称与著名的美国原住民部落无关；相反，它是指对原始软件代码的重复补丁。因此称之为，“一个修补的服务器”。
+
+### awk
+
+“awk(1) 代表着 Aho、Weinberger、Kernighan（作者）”—— Michael Greenberg
+
+### Bash
+
+“最初的 Unix shell，即 Bourne shell，是以其创造者的名字命名的。在开发出来 Bash 时，csh（发音为 ‘seashell’）实际上更受交互登录用户的欢迎。Bash 项目旨在赋予 Bourne shell 新的生命，使其更适合于交互式使用，因此它被命名为 ‘Bourne again shell’，是‘重生’的双关语。”——Ken Gaillot
+
+### C
+
+在早期，AT&T 的 Ken Thompson 和 Dennis Ritchie 发现可以使用更高级的编程语言（而不是低级的、可移植性更低的汇编编程）来编写操作系统和工具。早期有一个叫做 BCPL（基本组合编程语言）的编程系统，Thompson 创建了一个名为 B 的简化版 BCPL，但 B 的灵活性和速度都不高。然后，Ritchie 把 B 的思想扩展成一种叫做 C 的编译语言。”——Jim Hall
+
+### dd
+
+“我想你发表这样一篇文章不能不提到 dd。我的外号叫 Didi。发音正确的话听起来像 ‘dd’。我开始学的是 Unix，然后是 Linux，那是在 1993 年，当时我还是个学生。然后我去了军队，来到了我的部队中少数几个使用 Unix（Ultrix）的部门之一（其它部门主要是 VMS），那里的一个人说：‘这么说，你是一个黑客，对吗？你以为你了解 Unix 吗？好的，那么 dd 这个名字的是怎么来的呢？’我不知道，试着猜道：‘数据复印机？’所以他说，‘我要告诉你 dd 的故事。dd 是转换和复制的缩写（如今人们仍然可以在手册页中看到），但由于 cc 这个缩写已经被 C 编译器占用，所以它被命名为 dd。’就在几年后，我听闻了关于 JCL 的数据定义和 Unix dd 命令不统一的、半开玩笑的语法的真实故事，某种程度是基于此的。”——Yedidyah Bar David
+
+### Emacs
+
+经典的反 vi编辑器，其名称的真正词源并不明显，因为它源自“编辑宏”。但是，它作为一个伟大的宗教亵渎和崇拜的对象，吸引了许多恶作剧般的缩写，例如“Escape Meta Alt Control Shift”（以调侃其对键盘的大量依赖），“8MB 并经常发生内存交换”（从那时起就很吃内存了），“最终分配了所有的计算机存储空间”和 “EMACS 使一台计算机慢”——改编自 Jargon File/Hacker's Dictionary
+
+### Enarx
+
+[Enarx][3] 是机密计算领域的一个新项目。该项目的设计原则之一是它应该是“可替代的”。因此最初的名字是“psilocybin”（著名的魔术蘑菇）。一般情况下，经理级别的人可能会对这个名称有所抵触，因此考虑使用新名称。该项目的两位创始人 Mike Bursell 和 Nathaniel McCallum 都是古老语言极客，因此他们考虑了许多不同的想法，包括 тайна（Tayna——俄语中代表秘密或神秘——虽然俄语并不是一门古老的语言，但你就不要在乎这些细节了），crypticon（希腊语的意思是完全私生的），cryptidion（希腊中表示小密室），arconus（拉丁语中表示秘密的褒义形容词），arcanum（拉丁语中表示秘密的中性形容词）和 ærn（盎格鲁撒克逊人表示地方、秘密的地方、壁橱、住所、房子，或小屋的词汇）。最后，由于各种原因，包括域名和 GitHub 项目名称的可用性，他们选择了 enarx，这是两个拉丁词根的组合：en-（表示内部）和 -arx（表示城堡、要塞或堡垒）。
+
+### GIMP
+
+没有 [GIMP][4] 我们会怎么样？GNU 图像处理项目多年来一直是开源的重要基础。[维基百科][5]指出，“1995 年，[Spencer Kimball][6] 和 [Peter Mattis][7] 在加州大学伯克利分校开始为实验计算设施开发 GIMP，这是一个为期一个学期的项目。”
+
+### GNOME
+
+你有没有想过为什么 GNOME 被称为 GNOME？根据[维基百科][8]，GNOME 最初是一个表示“GNU 网络对象模型环境”的缩写词。现在，该名称不再表示该项目，并且该项目已被放弃，但这个名称仍然保留了下来。[GNOME 3][9] 是 Fedora、红帽企业版、Ubuntu、Debian、SUSE Linux 企业版等发行版的默认桌面环境。
+
+### Java
+
+你能想象这种编程语言还有其它名称吗？Java 最初被称为 Oak，但是遗憾的是，Sun Microsystems 的法律团队由于已有该商标而否决了它。所以开发团队又重新给它命名。[据说][10]该语言的工作组在 1995 年 1 月举行了一次大规模的头脑风暴。许多其它名称也被扔掉了，包括 Silk、DNA、WebDancer 等。该团队不希望新名称与过度使用的术语“web”或“net”有任何关系。取而代之的是，他们在寻找更有活力、更有趣、更容易记住的东西。Java 满足了这些要求，并且奇迹般地，团队同意通过了！
+
+### Jupyter
+
+现在许多数据科学家和学生在工作中使用 [Jupyter][11] 笔记本。“Jupyter”这个名字是三种开源计算机语言的融合，这三种语言在这个笔记本中都有使用，在数据科学中也很突出：[Julia][12]、[Python][13] 和 [R][14]。
+
+### Kubernetes
+
+Kubernetes 源自希腊语中的舵手。Kubernetes 项目创始人 Craig McLuckie 在 [2015 Hacker News][15] 回应中证实了这种词源。他坚持航海主题，解释说，这项技术可以驱动集装箱，就像舵手或驾驶员驾驶集装箱船一样，因此，他选择了 Kubernetes 这个名字。我们中的许多人仍然在尝试正确的发音（koo-bur-NET-eez），因此 替代使用 K8s 也是可以接受的。有趣的是，它与英语单词“行政长官”具有相同的词源，也与蒸汽机上的机械负反馈装置相同。
+
+### KDE
+
+那 K 桌面呢？KDE 最初代表“酷桌面环境”。 它由 [Matthias Ettrich][16] 于 1996 年创立。根据[维基百科][17]上的说法，该名称是对 Unix 上 [通用桌面环境][18]（CDE）一词的调侃。
+
+### Linux
+
+[Linux][19] 因其发明者 Linus Torvalds 的名字命名的。Linus 最初想将他的作品命名为“Freax”，因为他认为以他自己的名字命名太自负了。根据[维基百科][19]的说法，“赫尔辛基科技大学 Torvalds 的同事 Ari Lemmke 当时是 FTP 服务器的志愿管理员之一，他并不认为‘Freax’是个好名字。因此，他没有征询 Torvalds 就将服务器上的这个项目命名为‘Linux’。”
+
+以下是一些最受欢迎的 Linux 发行版。
+
+#### CentOS
+
+[CentOS][20] 是社区企业操作系统的缩写。它包含来自 Red Hat Enterprise Linux 的上游软件包。
+
+#### Debian
+
+[Debian][21] Linux 创建于 1993 年 9 月，是其创始人 Ian Murdock 和他当时的女友 Debra Lynn 的名字的混成词。
+
+#### RHEL
+
+[Red Hat Linux][22] 得名于它的创始人 Marc Ewing，他戴着一顶祖父送给他的康奈尔大学红色软呢帽。红帽公司成立于 1993 年 3 月 26 日。[Fedora Linux][23] 最初是一个志愿者项目，旨在为红帽发行版提供额外的软件，它的名字来自红帽的“Shadowman”徽标。
+
+#### Ubuntu
+
+[Ubuntu][24] 旨在广泛分享开源软件，它以非洲哲学“人的本质”命名，可以翻译为“对他人的人道主义”或“我之所以是我，是因为我们都是这样的人”。
+
+### Moodle
+
+开源学习平台 [Moodle][25] 是“模块化面向对象动态学习环境”的首字母缩写。Moodle 仍然是领先的线上学习平台。全球有近 10.4 万个注册的 Moodle 网站。
+
+另外两个流行的开源内容管理系统是 Drupal 和 Joomla。Drupal 的名字来自荷兰语 “druppel”，意思是“掉落”。根据维基百科，Joomla 是斯瓦希里语单词“jumla”的[英式拼写][26]，在阿拉伯语、乌尔都语和其他语言中是“在一起”的意思。
+
+### Mozilla
+
+[Mozilla][27] 是一个成立于 1998 年的开源软件社区。根据其网站，“Mozilla 项目创建于 1998 年，发布了 Netscape 浏览器套件源代码。其旨在利用互联网上成千上万的程序员的创造力，并推动浏览器市场上前所未有的创新水平。” 这个名字是 [Mosaic] [28] 和 Godzilla 的混成词。
+
+### Nginx
+
+“许多技术人员都试图装酷，并将它念成‘n’‘g’‘n’‘x’。实际上，很少的一些人做点基本的调查工作，就可以很快发现该名称实际上应该被念成是“EngineX”，指的是功能强大的 web 服务器，像个引擎。”——Jean Sebastien Tougne
+
+### Perl
+
+Perl 的创始人 Larry Wall 最初将他的项目命名为“Pearl”。根据维基百科，Wall 想给这种语言起一个有积极含义的简短名字。在 Perl 正式发布之前，Wall 发现了已有 [PEARL][29] 编程语言，于是更改了名称的拼写。
+
+### Piet 和 Mondrian
+
+“有两种编程语言以艺术家 Piet Mondrian 命名。一种叫做‘Piet’，另一种叫做‘Mondrian’。（David Morgan-Mar [写道][30]）：‘Piet 是一种编程语言，其中的程序看起来像抽象绘画。该语言以几何抽象艺术的开创者 Piet Mondrian 的名字命名。我曾想将这种语言命名为 Mondrian，但是有人告诉我这会让它看起来像一种很普通的脚本语言。哦，好吧，我想我们不能都是深奥的语言作家。’”——Yuval Lifshitz
+
+### Python
+
+Python 编程语言的独特名称来自其创建者 Guido Van Rossum，他是英国六人喜剧团体 Monty Python 的粉丝。
+
+### Raspberry Pi
+
+Raspberry Pi 以其微小但强大的功能和对低廉的价格而闻名，在开源社区中是最受欢迎的。但是它可爱（和好吃）的名字是从哪里来的呢？在 70 年代和 80 年代，以水果命名的计算机是一种流行的趋势。苹果、橘子、杏……有人饿了吗？根据创始人 Eben Upton 的 [2012 采访] [31]，“树莓派”这个名称是对这种趋势的致敬。树莓也很小，但却很有味道。名称中的“Pi”暗示着这样的事实：最初，该计算机只能运行 Python。
+
+### Samba
+
+[Server Message Block][32] 用于在 Linux 上共享 Windows 文件。
+
+### ScummVM
+
+[ScummVM][33]（《疯狂大楼》虚拟机的脚本创建实用程序）是一个程序，可以在现代计算机上运行一些经典的计算机冒险游戏。最初，它旨在玩用 SCUMM 构建的 LucasArts 的冒险游戏，该游戏最初用于开发《疯狂大楼》，后来又被用来开发 LucasArts 的其它大多数冒险游戏。目前，ScummVM 支持大量游戏引擎，包括 Sierra Online 的 AGI 和 SCI，但仍保留着名称 ScummVM。
+
+有一个相关的项目 [ResidualVM][34] 之所以得名，是因为它涵盖了 ScummVM 未涵盖的“剩余的” LucasArts 冒险游戏。 ResidualVM 涵盖的 LucasArts 游戏是使用 GrimE（Grim Engine）开发的，该引擎最初用于开发 Grim Fandango，因此 ResidualVM 的名称是双关语。
+
+### SQL
+
+“你可能知道 SQL 代表结构化查询语言，但你知道为什么它经常被读作‘sequel’吗？它是作为原本的‘QUEL’（查询语言）的后续（如结局）而创建的。”——Ken Gaillot
+
+### XFCE
+
+[XFCE][35] 是由 [Olivier Fourdan][36] 创建的一个流行的桌面。它在 1996 年作为 CDE 的替代品出现，最初是 XForms 公共环境的缩写。
+
+### Zsh
+
+Zsh 是一个交互式登录 shell。1990 年，普林斯顿大学的学生 Paul Falstad 写了该 shell 的第一个版本。他在看到当时在普林斯顿大学担任助教的 Zhong Sha 的登录 ID（zsh）后，觉得这个名字听起来像 [shell 的好名字][37]，给它起了这个名字。
+
+还有更多的项目和名称还没有包括在这个列表中。请一定要在评论中分享你的收藏。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/open-source-name-origins
+
+作者：[Joshua Allen Holm][a]
+选题：[lujun9972][b]
+译者：[laingke](https://github.com/laingke)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/holmja
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/rh_003784_02_os.comcareers_resume_rh1x.png?itok=S3HGxi6E (A person writing.)
+[2]: https://httpd.apache.org/
+[3]: https://enarx.io
+[4]: https://www.gimp.org/
+[5]: https://en.wikipedia.org/wiki/GIMP
+[6]: https://en.wikipedia.org/wiki/Spencer_Kimball_(computer_programmer)
+[7]: https://en.wikipedia.org/wiki/Peter_Mattis
+[8]: https://en.wikipedia.org/wiki/GNOME
+[9]: https://www.gnome.org/gnome-3/
+[10]: https://www.javaworld.com/article/2077265/so-why-did-they-decide-to-call-it-java-.html
+[11]: https://jupyter.org/
+[12]: https://julialang.org/
+[13]: https://www.python.org/
+[14]: https://www.r-project.org/
+[15]: https://news.ycombinator.com/item?id=9653797
+[16]: https://en.wikipedia.org/wiki/Matthias_Ettrich
+[17]: https://en.wikipedia.org/wiki/KDE
+[18]: https://sourceforge.net/projects/cdesktopenv/
+[19]: https://en.wikipedia.org/wiki/Linux
+[20]: https://www.centos.org/
+[21]: https://www.debian.org/
+[22]: https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux
+[23]: https://getfedora.org/
+[24]: https://ubuntu.com/about
+[25]: https://moodle.org/
+[26]: https://en.wikipedia.org/wiki/Joomla#Historical_background
+[27]: https://www.mozilla.org/en-US/
+[28]: https://en.wikipedia.org/wiki/Mosaic_(web_browser)
+[29]: https://en.wikipedia.org/wiki/PEARL_(programming_language)
+[30]: http://www.dangermouse.net/esoteric/piet.html
+[31]: https://www.techspot.com/article/531-eben-upton-interview/
+[32]: https://www.samba.org/
+[33]: https://www.scummvm.org/
+[34]: https://www.residualvm.org/
+[35]: https://www.xfce.org/
+[36]: https://en.wikipedia.org/wiki/Olivier_Fourdan
+[37]: http://www.zsh.org/mla/users/2005/msg00951.html
diff --git a/published/20191007 Using the Java Persistence API.md b/published/20191007 Using the Java Persistence API.md
new file mode 100644
index 0000000000..8f5c20d3cc
--- /dev/null
+++ b/published/20191007 Using the Java Persistence API.md
@@ -0,0 +1,265 @@
+[#]: collector: (lujun9972)
+[#]: translator: (runningwater)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11717-1.html)
+[#]: subject: (Using the Java Persistence API)
+[#]: via: (https://opensource.com/article/19/10/using-java-persistence-api)
+[#]: author: (Stephon Brown https://opensource.com/users/stephb)
+
+使用 Java 持久化 API
+======
+
+> 我们通过为自行车商店构建示例应用程序来学习如何使用 JPA。
+
+
+
+对应用开发者来说，Java 持久化 API（JPA）是一项重要的 java 功能，需要透彻理解。它为 Java 开发人员定义了如何将对象的方法调用转换为访问、持久化及管理存储在 NoSQL 和关系型数据库中的数据的方案。
+
+本文通过构建自行车借贷服务的教程示例来详细研究 JPA。此示例会使用 Spring Boot 框架、MongoDB 数据库（[已经不开源][2]）和 Maven 包管理来构建一个大型应用程序，并且构建一个创建、读取、更新和删除（CRUD）层。这儿我选择 NetBeans 11 作为我的 IDE。
+
+此教程仅从开源的角度来介绍 Java 持久化 API 的工作原理，不涉及其作为工具的使用说明。这全是关于编写应用程序模式的学习，但对于理解具体的软件实现也很益处。可以从我的 [GitHub 仓库][3]来获取相关代码。
+
+### Java: 不仅仅是“豆子”
+
+Java 是一门面向对象的编程语言，自 1996 年发布第一版 Java 开发工具（JDK）起，已经变化了很多很多。要了解其各种发展及其虚拟机本身就是一堂历史课。简而言之，和 Linux 内核很相似，自发布以来，该语言已经向多个方向分支发展。有对社区免费的标准版本、有针对企业的企业版本及由多家供应商提供的开源替代品。主要版本每六个月发布一次，其功能往往差异很大，所以确认选用版本前得先做些研究。
+
+总而言之，Java 的历史很悠久。本教程重点介绍 Java 11 的开源实现 [JDK 11][4]。因其是仍然有效的长期支持版本之一。
+
+ * **Spring Boot** 是由 Pivotal 公司开发的大型 Spring 框架的一个模块。Spring 是 Java 开发中一个非常流行的框架。它支持各种框架和配置，也为 WEB 应用程序及安全提供了保障。Spring Boot 为快速构建各种类型的 Java 项目提供了基本的配置。本教程使用 Spring Boot 来快速编写控制台应用程序并针对数据库编写测试用例。
+ * **Maven** 是由 Apache 开发的项目/包管理工具。Maven 通过 `POM.xml` 文件来管理包及其依赖项。如果你使用过 NPM 的话，可能会非常熟悉包管理器的功能。此外 Maven 也用来进行项目构建及生成功能报告。
+ * **Lombok** 是一个库，它通过在对象文件里面添加注解来自动创建 getters/setters 方法。像 C# 这些语言已经实现了此功能，Lombok 只是把此功能引入 Java 语言而已。
+ * **NetBeans** 是一款很流行的开源 IDE，专门用于 Java 开发。它的许多工具都随着 Java SE 和 EE 的版本更新而更新。
+
+我们会用这组工具为一个虚构自行车商店创建一个简单的应用程序。会实现对 `Customer` 和 `Bike` 对象集合的的插入操作。
+
+### 酿造完美
+
+导航到 [Spring Initializr][5] 页面。该网站可以生成基于 Spring Boot 和其依赖项的基本项目。选择以下选项：
+
+ 1. **项目：** Maven 工程
+ 2. **语言：** Java
+ 3. **Spring Boot：** 2.1.8（或最稳定版本）
+ 4. **项目元数据：** 无论你使用什么名字，其命名约定都是像 `com.stephb` 这样的。
+ * 你可以保留 Artifact 名字为 “Demo”。
+ 5. **依赖项：** 添加：
+ * Spring Data MongoDB
+ * Lombok
+
+点击 **下载**，然后用你的 IDE（例如 NetBeans） 打开此新项目。
+
+#### 模型层概要
+
+在项目里面，模型代表从数据库里取出的信息的具体对象。我们关注两个对象：`Customer` 和 `Bike`。首先，在 `src` 目录创建 `dto` 目录；然后，创建两个名为 `Customer.java` 和 `Bike.java` 的 Java 类对象文件。其结构如下示：
+
+```Java
+package com.stephb.JavaMongo.dto;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.data.annotation.Id;
+
+/**
+ *
+ * @author stephon
+ */
+@Getter @Setter
+public class Customer {
+
+ private @Id String id;
+ private String emailAddress;
+ private String firstName;
+ private String lastName;
+ private String address;
+
+}
+```
+
+*Customer.Java*
+
+```Java
+package com.stephb.JavaMongo.dto;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.data.annotation.Id;
+
+/**
+ *
+ * @author stephon
+ */
+@Getter @Setter
+public class Bike {
+ private @Id String id;
+ private String modelNumber;
+ private String color;
+ private String description;
+
+ @Override
+ public String toString() {
+ return "This bike model is " + this.modelNumber + " is the color " + this.color + " and is " + description;
+ }
+}
+```
+
+*Bike.java*
+
+如你所见，对象中使用 Lombok 注解来为定义的属性/特性生成 getters/setters 方法。如果你不想对该类的所有特性都生成 getters/setters 方法，可以在属性上专门定义这些注解。这两个类会变成容器，里面携带有数据，无论在何处想显示信息都可以使用。
+
+#### 配置数据库
+
+我使用 [Mongo Docker][7] 容器来进行此次测试。如果你的系统上已经安装了 MongoDB，则不必运行 Docker 实例。你也可以登录其官网，选择系统信息，然后按照安装说明来安装 MongoDB。
+
+安装后，就可以使用命令行、GUI（例如 MongoDB Compass）或用于连接数据源的 IDE 驱动程序来与新的 MongoDB 服务器进行交互。到目前为止，可以开始定义数据层了，用来拉取、转换和持久化数据。需要设置数据库访问属性，请导航到程序中的 `applications.properties` 文件，然后添加如下内容：
+
+```
+spring.data.mongodb.host=localhost
+spring.data.mongodb.port=27017
+spring.data.mongodb.database=BikeStore
+```
+
+#### 定义数据访问对象/数据访问层
+
+数据访问层（DAL）中的数据访问对象（DAO）定义了与数据库中的数据的交互过程。令人惊叹的就是在使用 `spring-boot-starter` 后，查询数据库的大部分工作已经完成。
+
+让我们从 `Customer` DAO 开始。在 `src` 下的新目录 `dao` 中创建一个接口文件，然后再创建一个名为 `CustomerRepository.java` 的 Java 类文件，其内容如下示：
+
+```
+package com.stephb.JavaMongo.dao;
+
+import com.stephb.JavaMongo.dto.Customer;
+import java.util.List;
+import org.springframework.data.mongodb.repository.MongoRepository;
+
+/**
+ *
+ * @author stephon
+ */
+public interface CustomerRepository extends MongoRepository{
+ @Override
+ public List findAll();
+ public List findByFirstName(String firstName);
+ public List findByLastName(String lastName);
+}
+```
+
+这个类是一个接口，扩展或继承于 `MongoRepository` 类，而 `MongoRepository` 类依赖于 DTO （`Customer.java`）和一个字符串，它们用来实现自定义函数查询功能。因为你已继承自此类，所以你可以访问许多方法函数，这些函数允许持久化和查询对象，而无需实现或引用自己定义的方法函数。例如，在实例化 `CustomerRepository` 对象后，你就可以直接使用 `Save` 函数。如果你需要扩展更多的功能，也可以重写这些函数。我创建了一些自定义查询来搜索我的集合，这些集合对象是我自定义的元素。
+
+`Bike` 对象也有一个存储源负责与数据库交互。与 `CustomerRepository` 的实现非常类似。其实现如下所示：
+
+```
+package com.stephb.JavaMongo.dao;
+
+import com.stephb.JavaMongo.dto.Bike;
+import java.util.List;
+import org.springframework.data.mongodb.repository.MongoRepository;
+
+/**
+ *
+ * @author stephon
+ */
+public interface BikeRepository extends MongoRepository{
+ public Bike findByModelNumber(String modelNumber);
+ @Override
+ public List findAll();
+ public List findByColor(String color);
+}
+```
+
+#### 运行程序
+
+现在，你已经有了一种结构化数据的方式，可以对数据进行提取、转换和持久化，然后运行这个程序。
+
+找到 `Application.java` 文件（有可能不是此名称，具体取决于你的应用程序名称，但都会包含有 “application” ）。在定义此类的地方，在后面加上 `implements CommandLineRunner`。这将允许你实现 `run` 方法来创建命令行应用程序。重写 `CommandLineRunner` 接口提供的 `run` 方法，并包含如下内容用来测试 `BikeRepository` ：
+
+```
+package com.stephb.JavaMongo;
+
+import com.stephb.JavaMongo.dao.BikeRepository;
+import com.stephb.JavaMongo.dao.CustomerRepository;
+import com.stephb.JavaMongo.dto.Bike;
+import java.util.Scanner;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+
+@SpringBootApplication
+public class JavaMongoApplication implements CommandLineRunner {
+ @Autowired
+ private BikeRepository bikeRepo;
+ private CustomerRepository custRepo;
+
+ public static void main(String[] args) {
+ SpringApplication.run(JavaMongoApplication.class, args);
+ }
+ @Override
+ public void run(String... args) throws Exception {
+ Scanner scan = new Scanner(System.in);
+ String response = "";
+ boolean running = true;
+ while(running){
+ System.out.println("What would you like to create? \n C: The Customer \n B: Bike? \n X:Close");
+ response = scan.nextLine();
+ if ("B".equals(response.toUpperCase())) {
+ String[] bikeInformation = new String[3];
+ System.out.println("Enter the information for the Bike");
+ System.out.println("Model Number");
+ bikeInformation[0] = scan.nextLine();
+ System.out.println("Color");
+ bikeInformation[1] = scan.nextLine();
+ System.out.println("Description");
+ bikeInformation[2] = scan.nextLine();
+
+ Bike bike = new Bike();
+ bike.setModelNumber(bikeInformation[0]);
+ bike.setColor(bikeInformation[1]);
+ bike.setDescription(bikeInformation[2]);
+
+ bike = bikeRepo.save(bike);
+ System.out.println(bike.toString());
+
+
+ } else if ("X".equals(response.toUpperCase())) {
+ System.out.println("Bye");
+ running = false;
+ } else {
+ System.out.println("Sorry nothing else works right now!");
+ }
+ }
+
+ }
+}
+```
+
+其中的 `@Autowired` 注解会自动依赖注入 `BikeRepository` 和 `CustomerRepository` Bean。我们将使用这些类来从数据库持久化和采集数据。
+
+已经好了。你已经创建了一个命令行应用程序。该应用程序连接到数据库，并且能够以最少的代码执行 CRUD 操作
+
+### 结论
+
+从诸如对象和类之类的编程语言概念转换为用于在数据库中存储、检索或更改数据的调用对于构建应用程序至关重要。Java 持久化 API（JPA）正是为 Java 开发人员解决这一难题的重要工具。你正在使用 Java 操纵哪些数据库呢？请在评论中分享。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/using-java-persistence-api
+
+作者：[Stephon Brown][a]
+选题：[lujun9972][b]
+译者：[runningwater](https://github.com/runningwater)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/stephb
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/java-coffee-beans.jpg?itok=3hkjX5We (Coffee beans)
+[2]: https://www.techrepublic.com/article/mongodb-ceo-tells-hard-truths-about-commercial-open-source/
+[3]: https://github.com/StephonBrown/SpringMongoJava
+[4]: https://openjdk.java.net/projects/jdk/11/
+[5]: https://start.spring.io/
+[6]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+string
+[7]: https://hub.docker.com/_/mongo
+[8]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+exception
+[9]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+system
diff --git a/published/20191017 How to type emoji on Linux.md b/published/20191017 How to type emoji on Linux.md
new file mode 100644
index 0000000000..7c11e45b76
--- /dev/null
+++ b/published/20191017 How to type emoji on Linux.md
@@ -0,0 +1,140 @@
+[#]: collector: (lujun9972)
+[#]: translator: (HankChow)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11702-1.html)
+[#]: subject: (How to type emoji on Linux)
+[#]: via: (https://opensource.com/article/19/10/how-type-emoji-linux)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+如何在 Linux 系统中输入 emoji
+======
+
+> 使用 GNOME 桌面可以让你在文字中轻松加入 emoji。
+
+
+
+emoji 是潜藏在 Unicode 字符空间里的有趣表情图，它们已经风靡于整个互联网。emoji 可以用来在社交媒体上表示自己的心情状态，也可以作为重要文件名的视觉标签，总之它们的各种用法层出不穷。在 Linux 系统中有很多种方式可以输入 Unicode 字符，但 GNOME 桌面能让你更轻松地查找和输入 emoji。
+
+![Emoji in Emacs][2]
+
+### 准备工作
+
+首先，你需要一个运行 [GNOME][3] 桌面的 Linux 系统。
+
+同时还需要安装一款支持 emoji 的字体。符合这个要求的字体有很多，使用你喜欢的软件包管理器直接搜索 `emoji` 并选择一款安装就可以了。
+
+例如在 Fedora 上：
+
+```
+$ sudo dnf search emoji
+emoji-picker.noarch : An emoji selection tool
+unicode-emoji.noarch : Unicode Emoji Data Files
+eosrei-emojione-fonts.noarch : A color emoji font
+twitter-twemoji-fonts.noarch : Twitter Emoji for everyone
+google-android-emoji-fonts.noarch : Android Emoji font released by Google
+google-noto-emoji-fonts.noarch : Google “Noto Emoji” Black-and-White emoji font
+google-noto-emoji-color-fonts.noarch : Google “Noto Color Emoji” colored emoji font
+[...]
+```
+
+对于 Ubuntu 或者 Debian，需要使用 `apt search`。
+
+在这篇文章中，我会使用 [Google Noto Color Emoji][4] 这款字体为例。
+
+### 设置
+
+要开始设置，首先打开 GNOME 的设置面板。
+
+1、在左边侧栏中，选择“地区与语言”类别。
+
+2、点击“输入源”选项下方的加号（+）打开“添加输入源”面板。
+
+![Add a new input source][5]
+
+3、在“添加输入源”面板中，点击底部的菜单按钮。
+
+![Add an Input Source panel][6]
+
+4、滑动到列表底部并选择“其它”。
+
+5、在“其它”列表中，找到“其它（快速输入）”。
+
+![Find Other \(Typing Booster\) in inputs][7]
+
+6、点击右上角的“添加”按钮，将输入源添加到 GNOME 桌面。
+
+以上操作完成之后，就可以关闭设置面板了。
+
+#### 切换到快速输入
+
+现在 GNOME 桌面的右上角会出现一个新的图标，一般情况下是当前语言的双字母缩写（例如英语是 en，世界语是 eo，西班牙语是 es，等等）。如果你按下了超级键（也就是键盘上带有 Linux 企鹅/Windows 徽标/Mac Command 标志的键）+ 空格键的组合键，就会切换到输入列表中的下一个输入源。在这里，我们只有两个输入源，也就是默认语言和快速输入。
+
+你可以尝试使用一下这个组合键，观察图标的变化。
+
+#### 配置快速输入
+
+在快速输入模式下，点击右上角的输入源图标，选择“Unicode 符号和 emoji 联想”选项，设置为“开”。
+
+![Set Unicode symbols and emoji predictions to On][8]
+
+现在快速输入模式已经可以输入 emoji 了。这正是我们现在所需要的，当然快速输入模式的功能也并不止于此。
+
+### 输入 emoji
+
+在快速输入模式下，打开一个文本编辑器，或者网页浏览器，又或者是任意一种支持输入 Unicode 字符的软件，输入“thumbs up”，快速输入模式就会帮你迅速匹配的 emoji 了。
+
+![Typing Booster searching for emojis][9]
+
+要退出 emoji 模式，只需要再次使用超级键+空格键的组合键，输入源就会切换回你的默认输入语言。
+
+### 使用其它切换方式
+
+如果你觉得“超级键+空格键”这个组合用起来不顺手，你也可以换成其它键的组合。在 GNOME 设置面板中选择“设备”→“键盘”。
+
+在“键盘”页面中，将“切换到下一个输入源”更改为你喜欢的组合键。
+
+![Changing keystroke combination in GNOME settings][10]
+
+### 输入 Unicode
+
+实际上，现代键盘的设计只是为了输入 26 个字母以及尽可能多的数字和符号。但 ASCII 字符的数量已经比键盘上能看到的字符多得多了，遑论上百万个 Unicode 字符。因此，如果你想要在 Linux 应用程序中输入 Unicode，但又不想使用快速输入，你可以尝试一下 Unicode 输入。
+
+1. 打开任意一种支持输入 Unicode 字符的软件，但仍然使用你的默认输入语言
+2. 使用 `Ctrl+Shift+U` 组合键进入 Unicode 输入模式
+3. 在 Unicode 输入模式下，只需要输入某个 Unicode 字符的对应序号，就实现了对这个 Unicode 字符的输入。例如 `1F44D` 对应的是 👍，而 `2620` 则对应了 ☠。想要查看所有 Unicode 字符的对应序号，可以参考 [Unicode 规范][11]。
+
+### emoji 的实用性
+
+emoji 可以让你的文本变得与众不同，这就是它们有趣和富有表现力的体现。同时 emoji 也有很强的实用性，因为它们本质上是 Unicode 字符，在很多支持自定义字体的地方都可以用到它们，而且跟使用其它常规字符没有什么太大的差别。因此，你可以使用 emoji 来对不同的文件做标记，在搜索的时候就可以使用 emoji 把这些文件快速筛选出来。
+
+![Labeling a file with emoji][12]
+
+你可以在 Linux 中尽情地使用 emoji，因为 Linux 是一个对 Unicode 友好的环境，未来也会对 Unicode 有着越来越好的支持。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/how-type-emoji-linux
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[HankChow](https://github.com/HankChow)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc-lead_cat-keyboard.png?itok=fuNmiGV- "A cat under a keyboard."
+[2]: https://opensource.com/sites/default/files/uploads/emacs-emoji.jpg "Emoji in Emacs"
+[3]: https://www.gnome.org/
+[4]: https://www.google.com/get/noto/help/emoji/
+[5]: https://opensource.com/sites/default/files/uploads/gnome-setting-region-add.png "Add a new input source"
+[6]: https://opensource.com/sites/default/files/uploads/gnome-setting-input-list.png "Add an Input Source panel"
+[7]: https://opensource.com/sites/default/files/uploads/gnome-setting-input-other-typing-booster.png "Find Other (Typing Booster) in inputs"
+[8]: https://opensource.com/sites/default/files/uploads/emoji-input-on.jpg "Set Unicode symbols and emoji predictions to On"
+[9]: https://opensource.com/sites/default/files/uploads/emoji-input.jpg "Typing Booster searching for emojis"
+[10]: https://opensource.com/sites/default/files/uploads/gnome-setting-keyboard-switch-input.jpg "Changing keystroke combination in GNOME settings"
+[11]: http://unicode.org/emoji/charts/full-emoji-list.html
+[12]: https://opensource.com/sites/default/files/uploads/file-label.png "Labeling a file with emoji"
+
diff --git a/published/20191020 14 SCP Command Examples to Securely Transfer Files in Linux.md b/published/20191020 14 SCP Command Examples to Securely Transfer Files in Linux.md
new file mode 100644
index 0000000000..9fafdca9cf
--- /dev/null
+++ b/published/20191020 14 SCP Command Examples to Securely Transfer Files in Linux.md
@@ -0,0 +1,245 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11669-1.html)
+[#]: subject: (14 SCP Command Examples to Securely Transfer Files in Linux)
+[#]: via: (https://www.linuxtechi.com/scp-command-examples-in-linux/)
+[#]: author: (Pradeep Kumar https://www.linuxtechi.com/author/pradeep/)
+
+在 Linux 上安全传输文件的 14 SCP 命令示例
+======
+
+
+
+SCP（安全复制）是 Linux 和 Unix 之类的系统中的命令行工具，用于通过网络安全地跨系统传输文件和目录。当我们使用 `scp` 命令将文件和目录从本地系统复制到远程系统时，则在后端与远程系统建立了 ssh 连接。换句话说，我们可以说 `scp` 在后端使用了相同的 SSH 安全机制，它需要密码或密钥进行身份验证。
+
+![scp-command-examples-linux][2]
+
+在本教程中，我们将讨论 14 个有用的 Linux `scp` 命令示例。
+
+`scp` 命令语法：
+
+```
+# scp <选项> <文件或目录> 用户名@目标主机:/<文件夹>
+
+# scp <选项> 用户名@目标主机:/文件 <本地文件夹>
+```
+
+`scp` 命令的第一个语法演示了如何将文件或目录从本地系统复制到特定文件夹下的目标主机。
+
+`scp` 命令的第二种语法演示了如何将目标主机中的文件复制到本地系统中。
+
+下面列出了 `scp` 命令中使用最广泛的一些选项，
+
+* `-C` 启用压缩
+* `-i` 指定识别文件或私钥
+* `-l` 复制时限制带宽
+* `-P` 指定目标主机的 ssh 端口号
+* `-p` 复制时保留文件的权限、模式和访问时间
+* `-q` 禁止 SSH 警告消息
+* `-r` 递归复制文件和目录
+* `-v` 详细输出
+
+现在让我们跳入示例！
+
+### 示例：1）使用 scp 将文件从本地系统复制到远程系统
+
+假设我们要使用 `scp` 命令将 jdk 的 rpm 软件包从本地 Linux 系统复制到远程系统（172.20.10.8），请使用以下命令，
+
+```
+[root@linuxtechi ~]$ scp jdk-linux-x64_bin.rpm root@linuxtechi:/opt
+root@linuxtechi's password:
+jdk-linux-x64_bin.rpm 100% 10MB 27.1MB/s 00:00
+[root@linuxtechi ~]$
+```
+
+上面的命令会将 jdk 的 rpm 软件包文件复制到 `/opt` 文件夹下的远程系统。
+
+### 示例：2）使用 scp 将文件从远程系统复制到本地系统
+
+假设我们想将文件从远程系统复制到本地系统下的 `/tmp` 文件夹，执行以下 `scp` 命令，
+
+```
+[root@linuxtechi ~]$ scp root@linuxtechi:/root/Technical-Doc-RHS.odt /tmp
+root@linuxtechi's password:
+Technical-Doc-RHS.odt 100% 1109KB 31.8MB/s 00:00
+[root@linuxtechi ~]$ ls -l /tmp/Technical-Doc-RHS.odt
+-rwx------. 1 pkumar pkumar 1135521 Oct 19 11:12 /tmp/Technical-Doc-RHS.odt
+[root@linuxtechi ~]$
+```
+
+### 示例：3）使用 scp 传输文件时的详细输出（-v）
+
+在 `scp` 命令中，我们可以使用 `-v` 选项启用详细输出。使用详细输出，我们可以轻松地发现后台确切发生了什么。这对于调试连接、认证和配置等问题非常有用。
+
+```
+root@linuxtechi ~]$ scp -v jdk-linux-x64_bin.rpm root@linuxtechi:/opt
+Executing: program /usr/bin/ssh host 172.20.10.8, user root, command scp -v -t /opt
+OpenSSH_7.8p1, OpenSSL 1.1.1 FIPS 11 Sep 2018
+debug1: Reading configuration data /etc/ssh/ssh_config
+debug1: Reading configuration data /etc/ssh/ssh_config.d/05-redhat.conf
+debug1: Reading configuration data /etc/crypto-policies/back-ends/openssh.config
+debug1: /etc/ssh/ssh_config.d/05-redhat.conf line 8: Applying options for *
+debug1: Connecting to 172.20.10.8 [172.20.10.8] port 22.
+debug1: Connection established.
+…………
+debug1: Next authentication method: password
+root@linuxtechi's password:
+```
+
+### 示例：4）将多个文件传输到远程系统
+
+可以使用 `scp` 命令一次性将多个文件复制/传输到远程系统，在 `scp` 命令中指定多个文件，并用空格隔开，示例如下所示
+
+```
+[root@linuxtechi ~]$ scp install.txt index.html jdk-linux-x64_bin.rpm root@linuxtechi:/mnt
+root@linuxtechi's password:
+install.txt 100% 0 0.0KB/s 00:00
+index.html 100% 85KB 7.2MB/s 00:00
+jdk-linux-x64_bin.rpm 100% 10MB 25.3MB/s 00:00
+[root@linuxtechi ~]$
+```
+
+### 示例：5）在两个远程主机之间传输文件
+
+使用 `scp` 命令，我们可以在两个远程主机之间复制文件和目录，假设我们有一个可以连接到两个远程 Linux 系统的本地 Linux 系统，因此从我的本地 Linux 系统中，我可以使用 `scp` 命令在这两个系统之间复制文件，
+
+命令语法：
+
+```
+# scp 用户名@远程主机1:/<要传输的文件> 用户名@远程主机2:/<文件夹>
+```
+
+示例如下：
+
+```
+# scp root@linuxtechi:~/backup-Oct.zip root@linuxtechi:/tmp
+# ssh root@linuxtechi "ls -l /tmp/backup-Oct.zip"
+-rwx------. 1 root root 747438080 Oct 19 12:02 /tmp/backup-Oct.zip
+```
+
+### 示例：6）递归复制文件和目录（-r）
+
+在 `scp` 命令中使用 `-r` 选项将整个目录从一个系统递归地复制到另一个系统，示例如下所示：
+
+```
+[root@linuxtechi ~]$ scp -r Downloads root@linuxtechi:/opt
+```
+
+使用以下命令验证 `Downloads` 文件夹是否已复制到远程系统，
+
+```
+[root@linuxtechi ~]$ ssh root@linuxtechi "ls -ld /opt/Downloads"
+drwxr-xr-x. 2 root root 75 Oct 19 12:10 /opt/Downloads
+[root@linuxtechi ~]$
+```
+
+### 示例：7）通过启用压缩来提高传输速度（-C）
+
+在 `scp` 命令中，我们可以通过使用 `-C` 选项启用压缩来提高传输速度，它将自动在源主机上启用压缩并在目标主机上解压缩。
+
+```
+root@linuxtechi ~]$ scp -r -C Downloads root@linuxtechi:/mnt
+```
+
+在以上示例中，我们正在启用压缩的情况下传输下载目录。
+
+### 示例：8）复制时限制带宽（-l）
+
+在 `scp` 命令中使用 `-l` 选项设置复制时对带宽使用的限制。带宽以 Kbit/s 为单位指定，示例如下所示：
+
+```
+[root@linuxtechi ~]$ scp -l 500 jdk-linux-x64_bin.rpm root@linuxtechi:/var
+```
+
+### 示例：9）在 scp 时指定其他 ssh 端口（-P）
+
+在某些情况下，目标主机上的 ssh 端口会更改，因此在使用 `scp` 命令时，我们可以使用 `-P` 选项指定 ssh 端口号。
+
+```
+[root@linuxtechi ~]$ scp -P 2022 jdk-linux-x64_bin.rpm root@linuxtechi:/var
+```
+
+在上面的示例中，远程主机的 ssh 端口为 “2022”。
+
+### 示例：10）复制时保留文件的权限、模式和访问时间（-p）
+
+从源复制到目标时，在 `scp` 命令中使用 `-p` 选项保留权限、访问时间和模式。
+
+```
+[root@linuxtechi ~]$ scp -p jdk-linux-x64_bin.rpm root@linuxtechi:/var/tmp
+jdk-linux-x64_bin.rpm 100% 10MB 13.5MB/s 00:00
+[root@linuxtechi ~]$
+```
+
+### 示例：11）在 scp 中以安静模式传输文件（-q）
+
+在 `scp` 命令中使用 `-q` 选项可禁止显示 ssh 的传输进度、警告和诊断消息。示例如下所示：
+
+```
+[root@linuxtechi ~]$ scp -q -r Downloads root@linuxtechi:/var/tmp
+[root@linuxtechi ~]$
+```
+
+### 示例：12）在传输时使用 scp 中的识别文件（-i）
+
+在大多数 Linux 环境中，首选基于密钥的身份验证。在 `scp` 命令中，我们使用 `-i` 选项指定识别文件（私钥文件），示例如下所示：
+
+```
+[root@linuxtechi ~]$ scp -i my_key.pem -r Downloads root@linuxtechi:/root
+```
+
+在上面的示例中，`my_key.pem` 是识别文件或私钥文件。
+
+### 示例：13）在 scp 中使用其他 ssh_config 文件（-F）
+
+在某些情况下，你使用不同的网络连接到 Linux 系统，可能某些网络位于代理服务器后面，因此在这种情况下，我们必须具有不同的 `ssh_config` 文件。
+
+通过 `-F` 选项在 `scp` 命令中指定了不同的 `ssh_config` 文件，示例如下所示：
+
+```
+[root@linuxtechi ~]$ scp -F /home/pkumar/new_ssh_config -r Downloads root@linuxtechi:/root
+root@linuxtechi's password:
+jdk-linux-x64_bin.rpm 100% 10MB 16.6MB/s 00:00
+backup-Oct.zip 100% 713MB 41.9MB/s 00:17
+index.html 100% 85KB 6.6MB/s 00:00
+[root@linuxtechi ~]$
+```
+
+### 示例：14）在 scp 命令中使用其他加密方式（-c）
+
+默认情况下，`scp` 使用 AES-128 加密方式来加密文件。如果你想在 `scp` 命令中使用其他加密方式，请使用 `-c` 选项，后接加密方式名称。
+
+假设我们要在用 `scp` 命令传输文件时使用 3des-cbc 加密方式，请运行以下 `scp` 命令：
+
+```
+[root@linuxtechi ~]# scp -c 3des-cbc -r Downloads root@linuxtechi:/root
+```
+
+使用以下命令列出 `ssh` 和 `scp` 支持的加密方式：
+
+```
+[root@linuxtechi ~]# ssh -Q cipher localhost | paste -d , -s -
+3des-cbc,aes128-cbc,aes192-cbc,aes256-cbc,root@linuxtechi,aes128-ctr,aes192-ctr,aes256-ctr,root@linuxtechi,root@linuxtechi,root@linuxtechi
+[root@linuxtechi ~]#
+```
+
+以上就是本教程的全部内容，要获取有关 `scp` 命令的更多详细信息，请参考其手册页。请在下面的评论部分中分享你的反馈和评论。
+
+--------------------------------------------------------------------------------
+
+via: https://www.linuxtechi.com/scp-command-examples-in-linux/
+
+作者：[Pradeep Kumar][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.linuxtechi.com/author/pradeep/
+[b]: https://github.com/lujun9972
+[1]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
+[2]: https://www.linuxtechi.com/wp-content/uploads/2019/10/scp-command-examples-linux.jpg
+[3]: https://www.linuxtechi.com/cdn-cgi/l/email-protection
diff --git a/published/20191022 How to program with Bash- Logical operators and shell expansions.md b/published/20191022 How to program with Bash- Logical operators and shell expansions.md
new file mode 100644
index 0000000000..31f0e3ef32
--- /dev/null
+++ b/published/20191022 How to program with Bash- Logical operators and shell expansions.md
@@ -0,0 +1,467 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11687-1.html)
+[#]: subject: (How to program with Bash: Logical operators and shell expansions)
+[#]: via: (https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+怎样用 Bash 编程：逻辑操作符和 shell 扩展
+======
+
+> 学习逻辑操作符和 shell 扩展，本文是三篇 Bash 编程系列的第二篇。
+
+
+
+Bash 是一种强大的编程语言，完美契合命令行和 shell 脚本。本系列（三篇文章，基于我的 [三集 Linux 自学课程][2]）讲解如何在 CLI 使用 Bash 编程。
+
+[第一篇文章][3] 讲解了 Bash 的一些简单命令行操作，包括如何使用变量和控制操作符。第二篇文章探讨文件、字符串、数字等类型和各种各样在执行流中提供控制逻辑的的逻辑运算符，还有 Bash 中的各类 shell 扩展。本系列第三篇也是最后一篇文章，将会探索能重复执行操作的 `for` 、`while` 和 `until` 循环。
+
+逻辑操作符是程序中进行判断的根本要素，也是执行不同的语句组合的依据。有时这也被称为流控制。
+
+### 逻辑操作符
+
+Bash 中有大量的用于不同条件表达式的逻辑操作符。最基本的是 `if` 控制结构，它判断一个条件，如果条件为真，就执行一些程序语句。操作符共有三类：文件、数字和非数字操作符。如果条件为真，所有的操作符返回真值（`0`），如果条件为假，返回假值（`1`）。
+
+这些比较操作符的函数语法是，一个操作符加一个或两个参数放在中括号内，后面跟一系列程序语句，如果条件为真，程序语句执行，可能会有另一个程序语句列表，该列表在条件为假时执行：
+
+
+```
+if [ arg1 operator arg2 ] ; then list
+或
+if [ arg1 operator arg2 ] ; then list ; else list ; fi
+```
+
+像例子中那样，在比较表达式中，空格不能省略。中括号的每部分，`[` 和 `]`，是跟 `test` 命令一样的传统的 Bash 符号：
+
+```
+if test arg1 operator arg2 ; then list
+```
+
+还有一个更新的语法能提供一点点便利，一些系统管理员比较喜欢用。这种格式对于不同版本的 Bash 和一些 shell 如 ksh（Korn shell）兼容性稍差。格式如下：
+
+```
+if [[ arg1 operator arg2 ]] ; then list
+```
+
+#### 文件操作符
+
+文件操作符是 Bash 中一系列强大的逻辑操作符。图表 1 列出了 20 多种不同的 Bash 处理文件的操作符。在我的脚本中使用频率很高。
+
+操作符 | 描述
+---|---
+`-a filename` | 如果文件存在，返回真值；文件可以为空也可以有内容，但是只要它存在，就返回真值
+`-b filename` | 如果文件存在且是一个块设备，如 `/dev/sda` 或 `/dev/sda1`，则返回真值
+`-c filename` | 如果文件存在且是一个字符设备，如 `/dev/TTY1`，则返回真值
+`-d filename` | 如果文件存在且是一个目录，返回真值
+`-e filename` | 如果文件存在，返回真值；与上面的 `-a` 相同
+`-f filename` | 如果文件存在且是一个一般文件，不是目录、设备文件或链接等的其他的文件，则返回 真值
+`-g filename` | 如果文件存在且 `SETGID` 标记被设置在其上，返回真值
+`-h filename` | 如果文件存在且是一个符号链接，则返回真值
+`-k filename` | 如果文件存在且粘滞位已设置，则返回真值
+`-p filename` | 如果文件存在且是一个命名的管道（FIFO），返回真值
+`-r filename` | 如果文件存在且有可读权限（它的可读位被设置），返回真值
+`-s filename` | 如果文件存在且大小大于 0，返回真值；如果一个文件存在但大小为 0，则返回假值
+`-t fd` | 如果文件描述符 `fd` 被打开且被关联到一个终端设备上，返回真值
+`-u filename` | 如果文件存在且它的 `SETUID` 位被设置，返回真值
+`-w filename` | 如果文件存在且有可写权限，返回真值
+`-x filename` | 如果文件存在且有可执行权限，返回真值
+`-G filename` | 如果文件存在且文件的组 ID 与当前用户相同，返回真值
+`-L filename` | 如果文件存在且是一个符号链接，返回真值（同 `-h`）
+`-N filename` | 如果文件存在且从文件上一次被读取后文件被修改过，返回真值
+`-O filename` | 如果文件存在且你是文件的拥有者，返回真值
+`-S filename` | 如果文件存在且文件是套接字，返回真值
+`file1 -ef file2` | 如果文件 `file1` 和文件 `file2` 指向同一设备的同一 INODE 号，返回真值（即硬链接）
+`file1 -nt file2` | 如果文件 `file1` 比 `file2` 新（根据修改日期），或 `file1` 存在而 `file2` 不存在，返回真值
+`file1 -ot file2` | 如果文件 `file1` 比 `file2` 旧（根据修改日期），或 `file1` 不存在而 `file2` 存在
+
+*图表 1：Bash 文件操作符*
+
+以测试一个文件存在与否来举例：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; if [ -e $File ] ; then echo "The file $File exists." ; else echo "The file $File does not exist." ; fi
+The file TestFile1 does not exist.
+[student@studentvm1 testdir]$
+```
+
+创建一个用来测试的文件，命名为 `TestFile1`。目前它不需要包含任何数据：
+
+```
+[student@studentvm1 testdir]$ touch TestFile1
+```
+
+在这个简短的 CLI 程序中，修改 `$File` 变量的值相比于在多个地方修改表示文件名的字符串的值要容易：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; if [ -e $File ] ; then echo "The file $File exists." ; else echo "The file $File does not exist." ; fi
+The file TestFile1 exists.
+[student@studentvm1 testdir]$
+```
+
+现在，运行一个测试来判断一个文件是否存在且长度不为 0（表示它包含数据）。假设你想判断三种情况：
+
+1. 文件不存在；
+2. 文件存在且为空；
+3. 文件存在且包含数据。
+
+因此，你需要一组更复杂的测试代码 — 为了测试所有的情况，使用 `if-elif-else` 结构中的 `elif` 语句：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; if [ -s $File ] ; then echo "$File exists and contains data." ; fi
+[student@studentvm1 testdir]$
+```
+
+在这个情况中，文件存在但不包含任何数据。向文件添加一些数据再运行一次：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; echo "This is file $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; fi
+TestFile1 exists and contains data.
+[student@studentvm1 testdir]$
+```
+
+这组语句能返回正常的结果，但是仅仅是在我们已知三种可能的情况下测试某种确切的条件。添加一段 `else` 语句，这样你就可以更精确地测试。把文件删掉，你就可以完整地测试这段新代码：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; rm $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi
+TestFile1 does not exist or is empty.
+```
+
+现在创建一个空文件用来测试：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi
+TestFile1 does not exist or is empty.
+```
+
+向文件添加一些内容，然后再测试一次：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; echo "This is file $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi
+TestFile1 exists and contains data.
+```
+
+现在加入 `elif` 语句来辨别是文件不存在还是文件为空：
+
+```
+[student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; elif [ -e $File ] ; then echo "$File exists and is empty." ; else echo "$File does not exist." ; fi
+TestFile1 exists and is empty.
+[student@studentvm1 testdir]$ File="TestFile1" ; echo "This is $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; elif [ -e $File ] ; then echo "$File exists and is empty." ; else echo "$File does not exist." ; fi
+TestFile1 exists and contains data.
+[student@studentvm1 testdir]$
+```
+
+现在你有一个可以测试这三种情况的 Bash CLI 程序，但是可能的情况是无限的。
+
+如果你能像保存在文件中的脚本那样组织程序语句，那么即使对于更复杂的命令组合也会很容易看出它们的逻辑结构。图表 2 就是一个示例。 `if-elif-else` 结构中每一部分的程序语句的缩进让逻辑更变得清晰。
+
+
+```
+File="TestFile1"
+echo "This is $File" > $File
+if [ -s $File ]
+ then
+ echo "$File exists and contains data."
+elif [ -e $File ]
+ then
+ echo "$File exists and is empty."
+else
+ echo "$File does not exist."
+fi
+```
+
+*图表 2: 像在脚本里一样重写书写命令行程序*
+
+对于大多数 CLI 程序来说，让这些复杂的命令变得有逻辑需要写很长的代码。虽然 CLI 可能是用 Linux 或 Bash 内置的命令，但是当 CLI 程序很长或很复杂时，创建一个保存在文件中的脚本将更有效，保存到文件中后，可以随时运行。
+
+#### 字符串比较操作符
+
+字符串比较操作符使我们可以对字符串中的字符按字母顺序进行比较。图表 3 列出了仅有的几个字符串比较操作符。
+
+操作符 | 描述
+---|---
+`-z string` | 如果字符串的长度为 0 ，返回真值
+`-n string` |如果字符串的长度不为 0 ，返回真值
+`string1 == string2` 或 `string1 = string2` | 如果两个字符串相等，返回真值。处于遵从 POSIX 一致性，在测试命令中应使用一个等号 `=`。与命令 `[[` 一起使用时，会进行如上描述的模式匹配（混合命令）。
+`string1 != string2` | 两个字符串不相等，返回真值
+`string1 < string2` | 如果对 `string1` 和 `string2` 按字母顺序进行排序，`string1` 排在 `string2` 前面（即基于地区设定的对所有字母和特殊字符的排列顺序）
+`string1 > string2` | 如果对 `string1` 和 `string2` 按字母顺序进行排序，`string1` 排在 `string2` 后面
+
+*图表 3: Bash 字符串逻辑操作符*
+
+首先，检查字符串长度。比较表达式中 `$MyVar` 两边的双引号不能省略（你仍应该在目录 `~/testdir` 下 ）。
+
+```
+[student@studentvm1 testdir]$ MyVar="" ; if [ -z "" ] ; then echo "MyVar is zero length." ; else echo "MyVar contains data" ; fi
+MyVar is zero length.
+[student@studentvm1 testdir]$ MyVar="Random text" ; if [ -z "" ] ; then echo "MyVar is zero length." ; else echo "MyVar contains data" ; fi
+MyVar is zero length.
+```
+
+你也可以这样做：
+
+```
+[student@studentvm1 testdir]$ MyVar="Random text" ; if [ -n "$MyVar" ] ; then echo "MyVar contains data." ; else echo "MyVar is zero length" ; fi
+MyVar contains data.
+[student@studentvm1 testdir]$ MyVar="" ; if [ -n "$MyVar" ] ; then echo "MyVar contains data." ; else echo "MyVar is zero length" ; fi
+MyVar is zero length
+```
+
+有时候你需要知道一个字符串确切的长度。这虽然不是比较，但是也与比较相关。不幸的是，计算字符串的长度没有简单的方法。有很多种方法可以计算，但是我认为使用 `expr`（求值表达式）命令是相对最简单的一种。阅读 `expr` 的手册页可以了解更多相关知识。注意表达式中你检测的字符串或变量两边的引号不要省略。
+
+```
+[student@studentvm1 testdir]$ MyVar="" ; expr length "$MyVar"
+0
+[student@studentvm1 testdir]$ MyVar="How long is this?" ; expr length "$MyVar"
+17
+[student@studentvm1 testdir]$ expr length "We can also find the length of a literal string as well as a variable."
+70
+```
+
+关于比较操作符，在我们的脚本中使用了大量的检测两个字符串是否相等（例如，两个字符串是否实际上是同一个字符串）的操作。我使用的是非 POSIX 版本的比较表达式：
+
+```
+[student@studentvm1 testdir]$ Var1="Hello World" ; Var2="Hello World" ; if [ "$Var1" == "$Var2" ] ; then echo "Var1 matches Var2" ; else echo "Var1 and Var2 do not match." ; fi
+Var1 matches Var2
+[student@studentvm1 testdir]$ Var1="Hello World" ; Var2="Hello world" ; if [ "$Var1" == "$Var2" ] ; then echo "Var1 matches Var2" ; else echo "Var1 and Var2 do not match." ; fi
+Var1 and Var2 do not match.
+```
+
+在你自己的脚本中去试一下这些操作符。
+
+#### 数字比较操作符
+
+数字操作符用于两个数字参数之间的比较。像其他类操作符一样，大部分都很容易理解。
+
+操作符 | 描述
+---|---
+`arg1 -eq arg2` | 如果 `arg1` 等于 `arg2`，返回真值
+`arg1 -ne arg2` | 如果 `arg1` 不等于 `arg2`，返回真值
+`arg1 -lt arg2` | 如果 `arg1` 小于 `arg2`，返回真值
+`arg1 -le arg2` | 如果 `arg1` 小于或等于 `arg2`，返回真值
+`arg1 -gt arg2` | 如果 `arg1` 大于 `arg2`，返回真值
+`arg1 -ge arg2` | 如果 `arg1` 大于或等于 `arg2`，返回真值
+
+*图表 4: Bash 数字比较逻辑操作符*
+
+来看几个简单的例子。第一个示例设置变量 `$X` 的值为 1，然后检测 `$X` 是否等于 1。第二个示例中，`$X` 被设置为 0，所以比较表达式返回结果不为真值。
+
+```
+[student@studentvm1 testdir]$ X=1 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi
+X equals 1
+[student@studentvm1 testdir]$ X=0 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi
+X does not equal 1
+[student@studentvm1 testdir]$
+```
+
+自己来多尝试一下其他的。
+
+#### 杂项操作符
+
+这些杂项操作符展示一个 shell 选项是否被设置，或一个 shell 变量是否有值，但是它不显示变量的值，只显示它是否有值。
+
+操作符 | 描述
+---|---
+`-o optname` | 如果一个 shell 选项 `optname` 是启用的（查看内建在 Bash 手册页中的 set `-o` 选项描述下面的选项列表），则返回真值
+`-v varname` | 如果 shell 变量 `varname` 被设置了值（被赋予了值），则返回真值
+`-R varname` | 如果一个 shell 变量 `varname` 被设置了值且是一个名字引用，则返回真值
+
+*图表 5: 杂项 Bash 逻辑操作符*
+
+自己来使用这些操作符实践下。
+
+### 扩展
+
+Bash 支持非常有用的几种类型的扩展和命令替换。根据 Bash 手册页，Bash 有七种扩展格式。本文只介绍其中五种：`~` 扩展、算术扩展、路径名称扩展、大括号扩展和命令替换。
+
+#### 大括号扩展
+
+大括号扩展是生成任意字符串的一种方法。（下面的例子是用特定模式的字符创建大量的文件。）大括号扩展可以用于产生任意字符串的列表，并把它们插入一个用静态字符串包围的特定位置或静态字符串的两端。这可能不太好想象，所以还是来实践一下。
+
+首先，看一下大括号扩展的作用：
+
+```
+[student@studentvm1 testdir]$ echo {string1,string2,string3}
+string1 string2 string3
+```
+
+看起来不是很有用，对吧？但是用其他方式使用它，再来看看：
+
+```
+[student@studentvm1 testdir]$ echo "Hello "{David,Jen,Rikki,Jason}.
+Hello David. Hello Jen. Hello Rikki. Hello Jason.
+```
+
+这看起来貌似有点用了 — 我们可以少打很多字。现在试一下这个：
+
+```
+[student@studentvm1 testdir]$ echo b{ed,olt,ar}s
+beds bolts bars
+```
+
+我可以继续举例，但是你应该已经理解了它的用处。
+
+#### ~ 扩展
+
+资料显示，使用最多的扩展是波浪字符（`~`）扩展。当你在命令中使用它（如 `cd ~/Documents`）时，Bash shell 把这个快捷方式展开成用户的完整的家目录。
+
+使用这个 Bash 程序观察 `~` 扩展的作用：
+
+```
+[student@studentvm1 testdir]$ echo ~
+/home/student
+[student@studentvm1 testdir]$ echo ~/Documents
+/home/student/Documents
+[student@studentvm1 testdir]$ Var1=~/Documents ; echo $Var1 ; cd $Var1
+/home/student/Documents
+[student@studentvm1 Documents]$
+```
+
+#### 路径名称扩展
+
+路径名称扩展是展开文件通配模式为匹配该模式的完整路径名称的另一种说法，匹配字符使用 `?` 和 `*`。文件通配指的是在大量操作中匹配文件名、路径和其他字符串时用特定的模式字符产生极大的灵活性。这些特定的模式字符允许匹配字符串中的一个、多个或特定字符。
+
+* `?` — 匹配字符串中特定位置的一个任意字符
+* `*` — 匹配字符串中特定位置的 0 个或多个任意字符
+
+这个扩展用于匹配路径名称。为了弄清它的用法，请确保 `testdir` 是当前工作目录（`PWD`），先执行基本的列出清单命令 `ls`（我家目录下的内容跟你的不一样）。
+
+```
+[student@studentvm1 testdir]$ ls
+chapter6 cpuHog.dos dmesg1.txt Documents Music softlink1 testdir6 Videos
+chapter7 cpuHog.Linux dmesg2.txt Downloads Pictures Templates testdir
+testdir cpuHog.mac dmesg3.txt file005 Public testdir tmp
+cpuHog Desktop dmesg.txt link3 random.txt testdir1 umask.test
+[student@studentvm1 testdir]$
+```
+
+现在列出以 `Do`、`testdir/Documents` 和 `testdir/Downloads` 开头的目录：
+
+```
+Documents:
+Directory01 file07 file15 test02 test10 test20 testfile13 TextFiles
+Directory02 file08 file16 test03 test11 testfile01 testfile14
+file01 file09 file17 test04 test12 testfile04 testfile15
+file02 file10 file18 test05 test13 testfile05 testfile16
+file03 file11 file19 test06 test14 testfile09 testfile17
+file04 file12 file20 test07 test15 testfile10 testfile18
+file05 file13 Student1.txt test08 test16 testfile11 testfile19
+file06 file14 test01 test09 test18 testfile12 testfile20
+
+Downloads:
+[student@studentvm1 testdir]$
+```
+
+然而，并没有得到你期望的结果。它列出了以 `Do` 开头的目录下的内容。使用 `-d` 选项，仅列出目录而不列出它们的内容。
+
+```
+[student@studentvm1 testdir]$ ls -d Do*
+Documents Downloads
+[student@studentvm1 testdir]$
+```
+
+在两个例子中，Bash shell 都把 `Do*` 模式展开成了匹配该模式的目录名称。但是如果有文件也匹配这个模式，会发生什么？
+
+```
+[student@studentvm1 testdir]$ touch Downtown ; ls -d Do*
+Documents Downloads Downtown
+[student@studentvm1 testdir]$
+```
+
+因此所有匹配这个模式的文件也被展开成了完整名字。
+
+#### 命令替换
+
+命令替换是让一个命令的标准输出数据流被当做参数传给另一个命令的扩展形式，例如，在一个循环中作为一系列被处理的项目。Bash 手册页显示：“命令替换可以让你用一个命令的输出替换为命令的名字。”这可能不太好理解。
+
+命令替换有两种格式：\`command\` 和 `$(command)`。在更早的格式中使用反引号（\`），在命令中使用反斜杠（`\`）来保持它转义之前的文本含义。然而，当用在新版本的括号格式中时，反斜杠被当做一个特殊字符处理。也请注意带括号的格式打开个关闭命令语句都是用一个括号。
+
+我经常在命令行程序和脚本中使用这种能力，一个命令的结果能被用作另一个命令的参数。
+
+来看一个非常简单的示例，这个示例使用了这个扩展的两种格式（再一次提醒，确保 `testdir` 是当前工作目录）：
+
+```
+[student@studentvm1 testdir]$ echo "Todays date is `date`"
+Todays date is Sun Apr 7 14:42:46 EDT 2019
+[student@studentvm1 testdir]$ echo "Todays date is $(date)"
+Todays date is Sun Apr 7 14:42:59 EDT 2019
+[student@studentvm1 testdir]$
+```
+
+`-seq` 工具用于一个数字序列：
+
+```
+[student@studentvm1 testdir]$ seq 5
+1
+2
+3
+4
+5
+[student@studentvm1 testdir]$ echo `seq 5`
+1 2 3 4 5
+[student@studentvm1 testdir]$
+```
+
+现在你可以做一些更有用处的操作，比如创建大量用于测试的空文件。
+
+```
+[student@studentvm1 testdir]$ for I in $(seq -w 5000) ; do touch file-$I ; done
+```
+
+`seq` 工具加上 `-w` 选项后，在生成的数字前面会用 0 补全，这样所有的结果都等宽，例如，忽略数字的值，它们的位数一样。这样在对它们按数字顺序进行排列时很容易。
+
+`seq -w 5000` 语句生成了 1 到 5000 的数字序列。通过把命令替换用于 `for` 语句，`for` 语句就可以使用该数字序列来生成文件名的数字部分。
+
+#### 算术扩展
+
+Bash 可以进行整型的数学计算，但是比较繁琐（你一会儿将看到）。数字扩展的语法是 `$((arithmetic-expression))` ，分别用两个括号来打开和关闭表达式。算术扩展在 shell 程序或脚本中类似命令替换；表达式结算后的结果替换了表达式，用于 shell 后续的计算。
+
+我们再用一个简单的用法来开始：
+
+```
+[student@studentvm1 testdir]$ echo $((1+1))
+2
+[student@studentvm1 testdir]$ Var1=5 ; Var2=7 ; Var3=$((Var1*Var2)) ; echo "Var 3 = $Var3"
+Var 3 = 35
+```
+
+下面的除法结果是 0，因为表达式的结果是一个小于 1 的整型数字：
+
+```
+[student@studentvm1 testdir]$ Var1=5 ; Var2=7 ; Var3=$((Var1/Var2)) ; echo "Var 3 = $Var3"
+Var 3 = 0
+```
+
+这是一个我经常在脚本或 CLI 程序中使用的一个简单的计算，用来查看在 Linux 主机中使用了多少虚拟内存。 `free` 不提供我需要的数据：
+
+```
+[student@studentvm1 testdir]$ RAM=`free | grep ^Mem | awk '{print $2}'` ; Swap=`free | grep ^Swap | awk '{print $2}'` ; echo "RAM = $RAM and Swap = $Swap" ; echo "Total Virtual memory is $((RAM+Swap))" ;
+RAM = 4037080 and Swap = 6291452
+Total Virtual memory is 10328532
+```
+
+我使用 \` 字符来划定用作命令替换的界限。
+
+我用 Bash 算术扩展的场景主要是用脚本检查系统资源用量后基于返回的结果选择一个程序运行的路径。
+
+### 总结
+
+本文是 Bash 编程语言系列的第二篇，探讨了 Bash 中文件、字符串、数字和各种提供流程控制逻辑的逻辑操作符还有不同种类的 shell 扩展。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_women_computing_5.png?itok=YHpNs_ss (Women in computing and open source v5)
+[2]: http://www.both.org/?page_id=1183
+[3]: https://linux.cn/article-11552-1.html
diff --git a/published/20191023 How to program with Bash- Loops.md b/published/20191023 How to program with Bash- Loops.md
new file mode 100644
index 0000000000..6a4d3ae653
--- /dev/null
+++ b/published/20191023 How to program with Bash- Loops.md
@@ -0,0 +1,336 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11714-1.html)
+[#]: subject: (How to program with Bash: Loops)
+[#]: via: (https://opensource.com/article/19/10/programming-bash-loops)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+怎样用 Bash 编程：循环
+======
+
+> 本文是 Bash 编程系列三篇中的最后一篇，来学习使用循环执行迭代的操作。
+
+
+
+Bash 是一种强大的用于命令行和 shell 脚本的编程语言。本系列的三部分都是基于我的三集 [Linux 自学课程][2] 写的，探索怎么用 CLI 进行 bash 编程。
+
+本系列的 [第一篇文章][3] 讨论了 bash 编程的一些简单命令行操作，如使用变量和控制操作符。[第二篇文章][4] 探讨了文件、字符串、数字等类型和各种各样在执行流中提供控制逻辑的的逻辑运算符，还有 bash 中不同种类的扩展。本文是第三篇（也是最后一篇），意在考察在各种迭代的操作中使用循环以及怎么合理控制循环。
+
+### 循环
+
+我使用过的所有编程语言都至少有两种循环结构来用来执行重复的操作。我经常使用 `for` 循环，然而我发现 `while` 和 `until` 循环也很有用处。
+
+#### for 循环
+
+我的理解是，在 bash 中实现的 `for` 命令比大部分语言灵活，因为它可以处理非数字的值；与之形成对比的是，诸如标准 C 语言的 `for` 循环只能处理数字类型的值。
+
+Bash 版的 `for` 命令基本的结构很简单：
+
+```
+for Var in list1 ; do list2 ; done
+```
+
+解释一下：“对于 `list1` 中的每一个值，把 `$Var` 设置为那个值，使用该值执行 `list2` 中的程序语句；`list1` 中的值都执行完后，整个循环结束，退出循环。” `list1` 中的值可以是一个简单的显式字符串值，也可以是一个命令执行后的结果（`` 包含其内的命令执行的结果，本系列第二篇文章中有描述）。我经常使用这种结构。
+
+要测试它，确认 `~/testdir` 仍然是当前的工作目录（PWD）。删除目录下所有东西，来看下这个显式写出值列表的 `for` 循环的简单的示例。这个列表混合了字母和数字 — 但是不要忘了，在 bash 中所有的变量都是字符串或者可以被当成字符串来处理。
+
+```
+[student@studentvm1 testdir]$ rm *
+[student@studentvm1 testdir]$ for I in a b c d 1 2 3 4 ; do echo $I ; done
+a
+b
+c
+d
+1
+2
+3
+4
+```
+
+给变量赋予更有意义的名字，变成前面版本的进阶版：
+
+```
+[student@studentvm1 testdir]$ for Dept in "Human Resources" Sales Finance "Information Technology" Engineering Administration Research ; do echo "Department $Dept" ; done
+Department Human Resources
+Department Sales
+Department Finance
+Department Information Technology
+Department Engineering
+Department Administration
+Department Research
+```
+
+创建几个目录（创建时显示一些处理信息）：
+
+```
+[student@studentvm1 testdir]$ for Dept in "Human Resources" Sales Finance "Information Technology" Engineering Administration Research ; do echo "Working on Department $Dept" ; mkdir "$Dept" ; done
+Working on Department Human Resources
+Working on Department Sales
+Working on Department Finance
+Working on Department Information Technology
+Working on Department Engineering
+Working on Department Administration
+Working on Department Research
+[student@studentvm1 testdir]$ ll
+total 28
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 Administration
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 Engineering
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 Finance
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 'Human Resources'
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 'Information Technology'
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 Research
+drwxrwxr-x 2 student student 4096 Apr 8 15:45 Sales
+```
+
+在 `mkdir` 语句中 `$Dept` 变量必须用引号包裹起来；否则名字中间有空格（如 `Information Technology`）会被当做两个独立的目录处理。我一直信奉的一条实践规则：所有的文件和目录都应该为一个单词（中间没有空格）。虽然大部分现代的操作系统可以处理名字中间有空格的情况，但是系统管理员需要花费额外的精力去确保脚本和 CLI 程序能正确处理这些特例。（即使它们很烦人，也务必考虑它们，因为你永远不知道将拥有哪些文件。）
+
+再次删除 `~/testdir` 下的所有东西 — 再运行一次下面的命令：
+
+```
+[student@studentvm1 testdir]$ rm -rf * ; ll
+total 0
+[student@studentvm1 testdir]$ for Dept in Human-Resources Sales Finance Information-Technology Engineering Administration Research ; do echo "Working on Department $Dept" ; mkdir "$Dept" ; done
+Working on Department Human-Resources
+Working on Department Sales
+Working on Department Finance
+Working on Department Information-Technology
+Working on Department Engineering
+Working on Department Administration
+Working on Department Research
+[student@studentvm1 testdir]$ ll
+total 28
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Administration
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Engineering
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Finance
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Human-Resources
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Information-Technology
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Research
+drwxrwxr-x 2 student student 4096 Apr 8 15:52 Sales
+```
+
+假设现在有个需求，需要列出一台 Linux 机器上所有的 RPM 包并对每个包附上简短的描述。我为北卡罗来纳州工作的时候，曾经遇到过这种需求。由于当时开源尚未得到州政府的“批准”，而且我只在台式机上使用 Linux，对技术一窍不通的老板（PHB）需要我列出我计算机上安装的所有软件，以便他们可以“批准”一个特例。
+
+你怎么实现它？有一种方法是，已知 `rpm –qa` 命令提供了 RPM 包的完整描述，包括了白痴老板想要的东西：软件名称和概要描述。
+
+让我们一步步执行出最后的结果。首先，列出所有的 RPM 包：
+
+```
+[student@studentvm1 testdir]$ rpm -qa
+perl-HTTP-Message-6.18-3.fc29.noarch
+perl-IO-1.39-427.fc29.x86_64
+perl-Math-Complex-1.59-429.fc29.noarch
+lua-5.3.5-2.fc29.x86_64
+java-11-openjdk-headless-11.0.ea.28-2.fc29.x86_64
+util-linux-2.32.1-1.fc29.x86_64
+libreport-fedora-2.9.7-1.fc29.x86_64
+rpcbind-1.2.5-0.fc29.x86_64
+libsss_sudo-2.0.0-5.fc29.x86_64
+libfontenc-1.1.3-9.fc29.x86_64
+<snip>
+```
+
+用 `sort` 和 `uniq` 命令对列表进行排序和打印去重后的结果（有些已安装的 RPM 包具有相同的名字）：
+
+
+```
+[student@studentvm1 testdir]$ rpm -qa | sort | uniq
+a2ps-4.14-39.fc29.x86_64
+aajohan-comfortaa-fonts-3.001-3.fc29.noarch
+abattis-cantarell-fonts-0.111-1.fc29.noarch
+abiword-3.0.2-13.fc29.x86_64
+abrt-2.11.0-1.fc29.x86_64
+abrt-addon-ccpp-2.11.0-1.fc29.x86_64
+abrt-addon-coredump-helper-2.11.0-1.fc29.x86_64
+abrt-addon-kerneloops-2.11.0-1.fc29.x86_64
+abrt-addon-pstoreoops-2.11.0-1.fc29.x86_64
+abrt-addon-vmcore-2.11.0-1.fc29.x86_64
+<snip>
+```
+
+以上命令得到了想要的 RPM 列表，因此你可以把这个列表作为一个循环的输入信息，循环最终会打印每个 RPM 包的详细信息：
+
+```
+[student@studentvm1 testdir]$ for RPM in `rpm -qa | sort | uniq` ; do rpm -qi $RPM ; done
+```
+
+这段代码产出了多余的信息。当循环结束后，下一步就是提取出白痴老板需要的信息。因此，添加一个 `egrep` 命令用来搜索匹配 `^Name` 或 `^Summary` 的行。脱字符（`^`）表示行首，整个命令表示显示所有以 Name 或 Summary 开头的行。
+
+```
+[student@studentvm1 testdir]$ for RPM in `rpm -qa | sort | uniq` ; do rpm -qi $RPM ; done | egrep -i "^Name|^Summary"
+Name : a2ps
+Summary : Converts text and other types of files to PostScript
+Name : aajohan-comfortaa-fonts
+Summary : Modern style true type font
+Name : abattis-cantarell-fonts
+Summary : Humanist sans serif font
+Name : abiword
+Summary : Word processing program
+Name : abrt
+Summary : Automatic bug detection and reporting tool
+<snip>
+```
+
+在上面的命令中你可以试试用 `grep` 代替 `egrep` ，你会发现用 `grep` 不能得到正确的结果。你也可以通过管道把命令结果用 `less` 过滤器来查看。最终命令像这样：
+
+```
+[student@studentvm1 testdir]$ for RPM in `rpm -qa | sort | uniq` ; do rpm -qi $RPM ; done | egrep -i "^Name|^Summary" > RPM-summary.txt
+```
+
+这个命令行程序用到了管道、重定向和 `for` 循环，这些全都在一行中。它把你的 CLI 程序的结果重定向到了一个文件，这个文件可以在邮件中使用或在其他地方作为输入使用。
+
+这个一次一步构建程序的过程让你能看到每步的结果，以此来确保整个程序以你期望的流程进行且输出你想要的结果。
+
+白痴老板最终收到了超过 1900 个不同的 RPM 包的清单，我严重怀疑根本就没人读过这个列表。我给了他们想要的东西，没有从他们嘴里听到过任何关于 RPM 包的信息。
+
+### 其他循环
+
+Bash 中还有两种其他类型的循环结构：`while` 和 `until` 结构，两者在语法和功能上都类似。这些循环结构的基础语法很简单：
+
+```
+while [ expression ] ; do list ; done
+```
+
+逻辑解释：表达式（`expression`）结果为 true 时，执行程序语句 `list`。表达式结果为 false 时，退出循环。
+
+```
+until [ expression ] ; do list ; done
+```
+
+逻辑解释：执行程序语句 `list`，直到表达式的结果为 true。当表达式结果为 true 时，退出循环。
+
+#### While 循环
+
+`while` 循环用于当逻辑表达式结果为 true 时执行一系列程序语句。假设你的 PWD 仍是 `~/testdir`。
+
+最简单的 `while` 循环形式是这个会一直运行下去的循环。下面格式的条件语句永远以 `true` 作为返回。你也可以用简单的 `1` 代替 `true`，结果一样，但是这解释了 true 表达式的用法。
+
+```
+[student@studentvm1 testdir]$ X=0 ; while [ true ] ; do echo $X ; X=$((X+1)) ; done | head
+0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+[student@studentvm1 testdir]$
+```
+
+既然你已经学了 CLI 的各部分知识，那就让它变得更有用处。首先，为了防止变量 `$X` 在前面的程序或 CLI 命令执行后有遗留的值，设置 `$X` 的值为 0。然后，因为逻辑表达式 `[ true ]` 的结果永远是 1，即 true，在 `do` 和 `done` 中间的程序指令列表会一直执行 — 或者直到你按下 `Ctrl+C` 抑或发送一个 2 号信号给程序。那些程序指令是算数扩展，用来打印变量 `$X` 当前的值并加 1.
+
+《[系统管理员的 Linux 哲学][5]》的信条之一是追求优雅，实现优雅的一种方式就是简化。你可以用操作符 `++` 来简化这个程序。在第一个例子中，变量当前的值被打印出来，然后变量的值增加了。可以在变量后加一个 `++` 来表示这个逻辑：
+
+```
+[student@studentvm1 ~]$ X=0 ; while [ true ] ; do echo $((X++)) ; done | head
+0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+```
+
+现在删掉程序最后的 `| head` 再运行一次。
+
+在下面这个版本中，变量在值被打印之前就自增了。这是通过在变量之前添加 `++` 操作符实现的。你能看出区别吗？
+
+```
+[student@studentvm1 ~]$ X=0 ; while [ true ] ; do echo $((++X)) ; done | head
+1
+2
+3
+4
+5
+6
+7
+8
+9
+```
+
+你已经把打印变量的值和自增简化到了一条语句。类似 `++` 操作符，也有 `--` 操作符。
+
+你需要一个在循环到某个特定数字时终止循环的方法。把 true 表达式换成一个数字比较表达式来实现它。这里有一个循环到 5 终止的程序。在下面的示例代码中，你可以看到 `-le` 是 “小于或等于” 的数字逻辑操作符。整个语句的意思：只要 `$X` 的值小于或等于 5，循环就一直运行。当 `$X` 增加到 6 时，循环终止。
+
+```
+[student@studentvm1 ~]$ X=0 ; while [ $X -le 5 ] ; do echo $((X++)) ; done
+0
+1
+2
+3
+4
+5
+[student@studentvm1 ~]$
+```
+
+#### Until 循环
+
+`until` 命令非常像 `while` 命令。不同之处是，它直到逻辑表达式的值是 `true` 之前，会一直循环。看一下这种结构最简单的格式：
+
+```
+[student@studentvm1 ~]$ X=0 ; until false ; do echo $((X++)) ; done | head
+0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+[student@studentvm1 ~]$
+```
+
+它用一个逻辑比较表达式来计数到一个特定的值：
+
+```
+[student@studentvm1 ~]$ X=0 ; until [ $X -eq 5 ] ; do echo $((X++)) ; done
+0
+1
+2
+3
+4
+[student@studentvm1 ~]$ X=0 ; until [ $X -eq 5 ] ; do echo $((++X)) ; done
+1
+2
+3
+4
+5
+[student@studentvm1 ~]$
+```
+
+### 总结
+
+本系列探讨了构建 Bash 命令行程序和 shell 脚本的很多强大的工具。但是这仅仅是你能用 Bash 做的很多有意思的事中的冰山一角，接下来就看你的了。
+
+我发现学习 Bash 编程最好的方法就是实践。找一个需要多个 Bash 命令的简单项目然后写一个 CLI 程序。系统管理员们要做很多适合 CLI 编程的工作，因此我确信你很容易能找到自动化的任务。
+
+很多年前，尽管我对其他的 Shell 语言和 Perl 很熟悉，但还是决定用 Bash 做所有系统管理员的自动化任务。我发现，有时稍微搜索一下，我可以用 Bash 实现我需要的所有事情。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/programming-bash-loops
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/fail_progress_cycle_momentum_arrow.png?itok=q-ZFa_Eh (arrows cycle symbol for failing faster)
+[2]: http://www.both.org/?page_id=1183
+[3]: https://linux.cn/article-11552-1.html
+[4]: https://linux.cn/article-11687-1.html
+[5]: https://www.apress.com/us/book/9781484237298
diff --git a/published/20191024 Get sorted with sort at the command line.md b/published/20191024 Get sorted with sort at the command line.md
new file mode 100644
index 0000000000..55916bdcad
--- /dev/null
+++ b/published/20191024 Get sorted with sort at the command line.md
@@ -0,0 +1,240 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11657-1.html)
+[#]: subject: (Get sorted with sort at the command line)
+[#]: via: (https://opensource.com/article/19/10/get-sorted-sort)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+在命令行用 sort 进行排序
+======
+
+> 在 Linux、BSD 或 Mac 的终端中使用 sort 命令，按自己的需求重新整理数据。
+
+
+
+如果你曾经用过数据表应用程序，你就会知道可以按列的内容对行进行排序。例如，如果你有一个费用列表，你可能希望对它们进行按日期或价格升序抑或按类别进行排序。如果你熟悉终端的使用，你不会仅为了排序文本数据就去使用庞大的办公软件。这正是 [sort][2] 命令的用处。
+
+### 安装
+
+你不必安装 `sort` ，因为它向来都包含在 [POSIX][3] 系统里。在大多数 Linux 系统中，`sort` 命令来自 GNU 组织打包的实用工具集合中。在其他的 POSIX 系统中，像 BSD 和 Mac，默认的 `sort` 命令不是 GNU 提供的，所以有一些选项可能不一样。本文中我尽量对 GNU 和 BSD 两者的实现都进行说明。
+
+### 按字母顺序排列行
+
+`sort` 命令默认会读取文件每行的第一个字符并对每行按字母升序排序后输出。两行中的第一个字符相同的情况下，对下一个字符进行对比。例如：
+
+```
+$ cat distro.list
+Slackware
+Fedora
+Red Hat Enterprise Linux
+Ubuntu
+Arch
+1337
+Mint
+Mageia
+Debian
+$ sort distro.list
+1337
+Arch
+Debian
+Fedora
+Mageia
+Mint
+Red Hat Enterprise Linux
+Slackware
+Ubuntu
+```
+
+使用 `sort` 不会改变原文件。`sort` 仅起到过滤的作用，所以如果你希望按排序后的格式保存数据，你需要用 `>` 或 `tee` 进行重定向。
+
+
+```
+$ sort distro.list | tee distro.sorted
+1337
+Arch
+Debian
+[...]
+$ cat distro.sorted
+1337
+Arch
+Debian
+[...]
+```
+
+### 按列排序
+
+复杂数据集有时候不止需要对每行的第一个字符进行排序。例如，假设有一个动物列表，每个都有其种和属，用可预见的分隔符分隔每一个“字段”（即数据表中的“单元格”）。这类由数据表导出的格式很常见，CSV（以逗号分隔的数据）后缀可以标识这些文件（虽然 CSV 文件不一定用逗号分隔，有分隔符的文件也不一定用 CSV 后缀）。以下数据作为示例：
+
+```
+Aptenodytes;forsteri;Miller,JF;1778;Emperor
+Pygoscelis;papua;Wagler;1832;Gentoo
+Eudyptula;minor;Bonaparte;1867;Little Blue
+Spheniscus;demersus;Brisson;1760;African
+Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
+Eudyptes;chrysocome;Viellot;1816;Southern Rockhopper
+Torvaldis;linux;Ewing,L;1996;Tux
+```
+
+对于这组示例数据，你可以用 `--field-separator` （在 BSD 和 Mac 用 `-t`，在 GNU 上也可以用简写 `-t` ）设置分隔符为分号（因为该示例数据中是用分号而不是逗号，理论上分隔符可以是任意字符），用 `--key`（在 BSD 和 Mac 上用 `-k`，在 GNU 上也可以用简写 `-k`）选项指定哪个字段被排序。例如，对每行第二个字段进行排序（计数以 1 开头而不是 0）：
+
+```
+sort --field-separator=";" --key=2
+Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
+Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
+Spheniscus;demersus;Brisson;1760;African
+Aptenodytes;forsteri;Miller,JF;1778;Emperor
+Torvaldis;linux;Ewing,L;1996;Tux
+Eudyptula;minor;Bonaparte;1867;Little Blue
+Pygoscelis;papua;Wagler;1832;Gentoo
+```
+
+结果有点不容易读，但是 Unix 以构造命令的管道方式而闻名，所以你可以使用 `column` 命令美化输出结果。使用 GNU `column`：
+
+```
+$ sort --field-separator=";" \
+\--key=2 penguins.list | column --table --separator ";"
+Megadyptes antipodes Milne-Edwards 1880 Yellow-eyed
+Eudyptes chrysocome Viellot 1816 Southern Rockhopper
+Spheniscus demersus Brisson 1760 African
+Aptenodytes forsteri Miller,JF 1778 Emperor
+Torvaldis linux Ewing,L 1996 Tux
+Eudyptula minor Bonaparte 1867 Little Blue
+Pygoscelis papua Wagler 1832 Gentoo
+```
+
+对于初学者可能有点不好理解（但是写起来简单），BSD 和 Mac 上的命令选项：
+
+```
+$ sort -t ";" \
+-k2 penguins.list | column -t -s ";"
+Megadyptes antipodes Milne-Edwards 1880 Yellow-eyed
+Eudyptes chrysocome Viellot 1816 Southern Rockhopper
+Spheniscus demersus Brisson 1760 African
+Aptenodytes forsteri Miller,JF 1778 Emperor
+Torvaldis linux Ewing,L 1996 Tux
+Eudyptula minor Bonaparte 1867 Little Blue
+Pygoscelis papua Wagler 1832 Gentoo
+```
+
+当然 `-k` 不一定非要设为 `2`。任意存在的字段都可以被设为排序的键。
+
+### 逆序排列
+
+你可以用 `--reverse`（BSD/Mac 上用 `-r`，GNU 上也可以用简写 `-r`）选项来颠倒已经排好序的列表。
+
+```
+$ sort --reverse alphabet.list
+z
+y
+x
+w
+[...]
+```
+
+你也可以把输出结果通过管道传给命令 [tac][4] 来实现相同的效果。
+
+### 按月排序（仅 GNU 支持）
+
+理想情况下，所有人都按照 ISO 8601 标准来写日期：年、月、日。这是一种合乎逻辑的指定精确日期的方法，也可以很容易地被计算机理解。也有很多情况下，人类用其他的方式标注日期，包括用很名字随意的月份。
+
+幸运的是，GNU `sort` 命令能识别这种写法，并可以按月份的名称正确排序。使用 `--month-sort`（`-M`）选项：
+
+```
+$ cat month.list
+November
+October
+September
+April
+[...]
+$ sort --month-sort month.list
+January
+February
+March
+April
+May
+[...]
+November
+December
+```
+
+月份的全称和简写都可以被识别。
+
+### 人类可读的数字排序（仅 GNU 支持）
+
+另一个人类和计算机的常见混淆点是数字的组合。例如，人类通常把 “1024 kilobytes” 写成 “1KB”，因为人类解析 “1 KB” 比 “1024” 要容易且更快（数字越大，这种差异越明显）。对于计算机来说，一个 9 KB 的字符串要比诸如 1 MB 的字符串大（尽管 9 KB 是 1 MB 很小一部分）。GNU `sort` 命令提供了`--human-numeric-sort`（`-h`）选项来帮助正确解析这些值。
+
+```
+$ cat sizes.list
+2M
+12MB
+1k
+9k
+900
+7000
+$ sort --human-numeric-sort
+900
+7000
+1k
+9k
+2M
+12MB
+```
+
+有一些情况例外。例如，“16000 bytes” 比 “1 KB” 大，但是 `sort` 识别不了。
+
+```
+$ cat sizes0.list
+2M
+12MB
+16000
+1k
+$ sort -h sizes0.list
+16000
+1k
+2M
+12MB
+```
+
+逻辑上来说，这个示例中 16000 应该写成 16 KB，所以也不应该全部归咎于GNU `sort`。只要你确保数字的一致性，`--human-numeric-sort` 可以用一种计算机友好的方式解析成人类可读的数字。
+
+### 随机排序（仅 GNU 支持）
+
+有时候工具也提供了一些与设计初衷相悖的选项。某种程度上说，`sort` 命令提供对一个文件进行随机排序的能力没有任何意义。这个命令的工作流让这个特性变得很方便。你*可以*用其他的命令，像 [shuf][5] ，或者你可以用现在的命令添加一个选项。不管你认为它是一个臃肿的还是极具创造力的用户体验设计，GNU `sort` 命令提供了对文件进行随机排序的功能。
+
+最纯粹的随机排序格式选项是 `--random-sort` 或 `-R`（不要跟 `-r` 混淆，`-r` 是 `--reverse` 的简写）。
+
+```
+$ sort --random-sort alphabet.list
+d
+m
+p
+a
+[...]
+```
+
+每次对文件运行随机排序都会有不同的结果。
+
+### 结语
+
+GNU 和 BSD 的 `sort` 命令还有很多功能，所以花点时间去了解这些选项。你会惊异于 `sort` 的灵活性，尤其是当它和其他的 Unix 工具一起使用时。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/get-sorted-sort
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_laptop_hack_work.png?itok=aSpcWkcl "Coding on a computer"
+[2]: https://en.wikipedia.org/wiki/Sort_(Unix)
+[3]: https://en.wikipedia.org/wiki/POSIX
+[4]: https://opensource.com/article/19/9/tac-command
+[5]: https://www.gnu.org/software/coreutils/manual/html_node/shuf-invocation.html
diff --git a/published/20191028 How to remove duplicate lines from files with awk.md b/published/20191028 How to remove duplicate lines from files with awk.md
new file mode 100644
index 0000000000..8a5148e708
--- /dev/null
+++ b/published/20191028 How to remove duplicate lines from files with awk.md
@@ -0,0 +1,222 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11666-1.html)
+[#]: subject: (How to remove duplicate lines from files with awk)
+[#]: via: (https://opensource.com/article/19/10/remove-duplicate-lines-files-awk)
+[#]: author: (Lazarus Lazaridis https://opensource.com/users/iridakos)
+
+怎样使用 awk 删掉文件中重复的行
+======
+
+> 学习怎样使用 awk 的 `!visited[$0]++` 在不重新排序或改变原排列顺序的前提下删掉重复的行。
+
+
+
+假设你有一个文本文件，你需要删掉所有重复的行。
+
+### TL;DR
+
+*要保持原来的排列顺序*删掉重复行，使用：
+
+```
+awk '!visited[$0]++' your_file > deduplicated_file
+```
+
+### 工作原理
+
+这个脚本维护一个关联数组，索引（键）为文件中去重后的行，每个索引对应的值为该行出现的次数。对于文件的每一行，如果这行（之前）出现的次数为 0，则值加 1，并打印这行，否则值加 1，不打印这行。
+
+我之前不熟悉 `awk`，我想弄清楚这么短小的一个脚本是怎么实现的。我调研了下，下面是调研心得：
+
+* 这个 awk “脚本” `!visited[$0]++` 对输入文件的*每一行*都执行。
+* `visited[]` 是一个[关联数组][2]（又名[映射][3]）类型的变量。`awk` 会在第一次执行时初始化它，因此我们不需要初始化。
+* `$0` 变量的值是当前正在被处理的行的内容。
+* `visited[$0]` 通过与 `$0`（正在被处理的行）相等的键来访问该映射中的值，即出现次数（我们在下面设置的）。
+* `!` 对表示出现次数的值取反：
+ * 在 `awk` 中，[任意非零的数或任意非空的字符串的值是 `true`][4]。
+ * [变量默认的初始值为空字符串][5]，如果被转换为数字，则为 0。
+ * 也就是说：
+ * 如果 `visited[$0]` 的值是一个比 0 大的数，取反后被解析成 `false`。
+ * 如果 `visited[$0]` 的值为等于 0 的数字或空字符串，取反后被解析成 `true` 。
+ * `++` 表示变量 `visited[$0]` 的值加 1。
+ * 如果该值为空，`awk` 自动把它转换为 `0`（数字） 后加 1。
+ * 注意：加 1 操作是在我们取到了变量的值之后执行的。
+
+总的来说，整个表达式的意思是：
+
+ * `true`：如果表示出现次数为 0 或空字符串
+ * `false`：如果出现的次数大于 0
+
+`awk` 由 [模式或表达式和一个与之关联的动作][6] 组成：
+
+```
+<模式/表达式> { <动作> }
+```
+
+如果匹配到了模式，就会执行后面的动作。如果省略动作，`awk` 默认会打印（`print`）输入。
+
+> 省略动作等价于 `{print $0}`。
+
+我们的脚本由一个 `awk` 表达式语句组成，省略了动作。因此这样写：
+
+```
+awk '!visited[$0]++' your_file > deduplicated_file
+```
+
+等于这样写：
+
+```
+awk '!visited[$0]++ { print $0 }' your_file > deduplicated_file
+```
+
+对于文件的每一行，如果表达式匹配到了，这行内容被打印到输出。否则，不执行动作，不打印任何东西。
+
+### 为什么不用 uniq 命令？
+
+`uniq` 命令仅能对相邻的行去重。这是一个示例：
+
+```
+$ cat test.txt
+A
+A
+A
+B
+B
+B
+A
+A
+C
+C
+C
+B
+B
+A
+$ uniq < test.txt
+A
+B
+A
+C
+B
+A
+```
+
+### 其他方法
+
+#### 使用 sort 命令
+
+我们也可以用下面的 [sort][7] 命令来去除重复的行，但是*原来的行顺序没有被保留*。
+
+
+```
+sort -u your_file > sorted_deduplicated_file
+```
+
+#### 使用 cat + sort + cut
+
+上面的方法会产出一个去重的文件，各行是基于内容进行排序的。[通过管道连接命令][8]可以解决这个问题。
+
+
+```
+cat -n your_file | sort -uk2 | sort -nk1 | cut -f2-
+```
+
+**工作原理**
+
+假设我们有下面一个文件：
+
+```
+abc
+ghi
+abc
+def
+xyz
+def
+ghi
+klm
+```
+
+`cat -n test.txt` 在每行前面显示序号：
+
+```
+1 abc
+2 ghi
+3 abc
+4 def
+5 xyz
+6 def
+7 ghi
+8 klm
+```
+
+`sort -uk2` 基于第二列（`k2` 选项）进行排序，对于第二列相同的值只保留一次（`u` 选项）：
+
+```
+1 abc
+4 def
+2 ghi
+8 klm
+5 xyz
+```
+
+`sort -nk1` 基于第一列排序（`k1` 选项），把列的值作为数字来处理（`-n` 选项）：
+
+```
+1 abc
+2 ghi
+4 def
+5 xyz
+8 klm
+```
+
+最后，`cut -f2-` 从第二列开始打印每一行，直到最后的内容（`-f2-` 选项：留意 `-` 后缀，它表示这行后面的内容都包含在内）。
+
+```
+abc
+ghi
+def
+xyz
+klm
+```
+
+### 参考
+
+* [GNU awk 用户手册][9]
+* [awk 中的数组][2]
+* [Awk — 真值][4]
+* [Awk 表达式][5]
+* [Unix 怎么删除文件中重复的行？][10]
+* [不用排序去掉重复的行（去重）][11]
+* ['!a[$0]++' 工作原理][12]
+
+以上为全文。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/10/remove-duplicate-lines-files-awk
+
+作者：[Lazarus Lazaridis][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/iridakos
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_laptop_hack_work.png?itok=aSpcWkcl (Coding on a computer)
+[2]: http://kirste.userpage.fu-berlin.de/chemnet/use/info/gawk/gawk_12.html
+[3]: https://en.wikipedia.org/wiki/Associative_array
+[4]: https://www.gnu.org/software/gawk/manual/html_node/Truth-Values.html
+[5]: https://ftp.gnu.org/old-gnu/Manuals/gawk-3.0.3/html_chapter/gawk_8.html
+[6]: http://kirste.userpage.fu-berlin.de/chemnet/use/info/gawk/gawk_9.html
+[7]: http://man7.org/linux/man-pages/man1/sort.1.html
+[8]: https://stackoverflow.com/a/20639730/2292448
+[9]: https://www.gnu.org/software/gawk/manual/html_node/
+[10]: https://stackoverflow.com/questions/1444406/how-can-i-delete-duplicate-lines-in-a-file-in-unix
+[11]: https://stackoverflow.com/questions/11532157/remove-duplicate-lines-without-sorting
+[12]: https://unix.stackexchange.com/questions/159695/how-does-awk-a0-work/159734#159734
+[13]: https://opensource.com/sites/default/files/uploads/duplicate-cat.jpg (Duplicate cat)
+[14]: https://iridakos.com/about/
+[15]: http://creativecommons.org/licenses/by-nc/4.0/
diff --git a/published/20191101 Awk one-liners and scripts to help you sort text files.md b/published/20191101 Awk one-liners and scripts to help you sort text files.md
new file mode 100644
index 0000000000..a22edd71eb
--- /dev/null
+++ b/published/20191101 Awk one-liners and scripts to help you sort text files.md
@@ -0,0 +1,242 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11684-1.html)
+[#]: subject: (Awk one-liners and scripts to help you sort text files)
+[#]: via: (https://opensource.com/article/19/11/how-sort-awk)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+帮助你排序文本文件的 Awk 命令行或脚本
+======
+
+> Awk 是一个强大的工具，可以执行某些可能由其它常见实用程序（包括 `sort`）来完成的任务。
+
+
+
+Awk 是个普遍存在的 Unix 命令，用于扫描和处理包含可预测模式的文本。但是，由于它具有函数功能，因此也可以合理地称之为编程语言。
+
+令人困惑的是，有不止一个 awk。（或者，如果你认为只有一个，那么其它几个就是克隆。）有 `awk`（由Aho、Weinberger 和 Kernighan 编写的原始程序），然后有 `nawk` 、`mawk` 和 GNU 版本的 `gawk`。GNU 版本的 awk 是该实用程序的一个高度可移植的自由软件版本，具有几个独特的功能，因此本文是关于 GNU awk 的。
+
+虽然它的正式名称是 `gawk`，但在 GNU+Linux 系统上，它的别名是 `awk`，并用作该命令的默认版本。 在其他没有带有 GNU awk 的系统上，你必须先安装它并将其称为 `gawk`，而不是 `awk`。本文互换使用术语 `awk` 和 `gawk`。
+
+`awk` 既是命令语言又是编程语言，这使其成为一个强大的工具，可以处理原本留给 `sort`、`cut`、`uniq` 和其他常见实用程序的任务。幸运的是，开源中有很多冗余空间，因此，如果你面临是否使用 `awk` 的问题，答案可能是肯定的“随便”。
+
+`awk` 的灵活之美在于，如果你已经确定使用 `awk` 来完成一项任务，那么无论接下来发生什么，你都可以继续使用 `awk`。这包括对数据排序而不是按交付给你的顺序的永恒需求。
+
+### 样本数据集
+
+在探索 `awk` 的排序方法之前，请生成要使用的样本数据集。保持简单，这样你就不会为极端情况和意想不到的复杂性所困扰。这是本文使用的样本集：
+
+```
+Aptenodytes;forsteri;Miller,JF;1778;Emperor
+Pygoscelis;papua;Wagler;1832;Gentoo
+Eudyptula;minor;Bonaparte;1867;Little Blue
+Spheniscus;demersus;Brisson;1760;African
+Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
+Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
+Torvaldis;linux;Ewing,L;1996;Tux
+```
+
+这是一个很小的数据集，但它提供了多种数据类型：
+
+* 属名和种名，彼此相关但又是分开的
+* 姓，有时是以逗号开头的首字母缩写
+* 代表日期的整数
+* 任意术语
+* 所有字段均以分号分隔
+
+根据你的教育背景，你可能会认为这是二维数组或表格，或者只是行分隔的数据集合。你如何看待它只是你的问题，而 `awk` 只认识文本。由你决定告诉 `awk` 你想如何解析它。
+
+### 只想排序
+
+如果你只想按特定的可定义字段（例如电子表格中的“单元格”）对文本数据集进行排序，则可以使用 [sort 命令][2]。
+
+### 字段和记录
+
+无论输入的格式如何，都必须在其中找到模式才可以专注于对你重要的数据部分。在此示例中，数据由两个因素定界：行和字段。每行都代表一个新的*记录*，就如你在电子表格或数据库转储中看到的一样。在每一行中，都有用分号（`;`）分隔的不同的*字段*（将其视为电子表格中的单元格）。
+
+`awk` 一次只处理一条记录，因此，当你在构造发给 `awk` 的这指令时，你可以只关注一行记录。写下你想对一行数据执行的操作，然后在下一行进行测试（无论是心理上还是用 `awk` 进行测试），然后再进行其它的一些测试。最后，你要对你的 `awk` 脚本要处理的数据做好假设，以便可以按你要的数据结构提供给你数据。
+
+在这个例子中，很容易看到每个字段都用分号隔开。为简单起见，假设你要按每行的第一字段对列表进行排序。
+
+在进行排序之前，你必须能够让 `awk` 只关注在每行的第一个字段上，因此这是第一步。终端中 awk 命令的语法为 `awk`，后跟相关选项，最后是要处理的数据文件。
+
+```
+$ awk --field-separator=";" '{print $1;}' penguins.list
+Aptenodytes
+Pygoscelis
+Eudyptula
+Spheniscus
+Megadyptes
+Eudyptes
+Torvaldis
+```
+
+因为字段分隔符是对 Bash shell 具有特殊含义的字符，所以必须将分号括在引号中或在其前面加上反斜杠。此命令仅用于证明你可以专注于特定字段。你可以使用另一个字段的编号尝试相同的命令，以查看数据的另一个“列”的内容：
+
+```
+$ awk --field-separator=";" '{print $3;}' penguins.list
+Miller,JF
+Wagler
+Bonaparte
+Brisson
+Milne-Edwards
+Viellot
+Ewing,L
+```
+
+我们尚未进行任何排序，但这是良好的基础。
+
+### 脚本编程
+
+`awk` 不仅仅是命令，它是一种具有索引、数组和函数的编程语言。这很重要，因为这意味着你可以获取要排序的字段列表，将列表存储在内存中，进行处理，然后打印结果数据。对于诸如此类的一系列复杂操作，在文本文件中进行操作会更容易，因此请创建一个名为 `sort.awk` 的新文件并输入以下文本：
+
+```
+#!/bin/gawk -f
+
+BEGIN {
+ FS=";";
+}
+```
+
+这会将该文件建立为 `awk` 脚本，该脚本中包含执行的行。
+
+`BEGIN` 语句是 `awk` 提供的特殊设置功能，用于只需要执行一次的任务。定义内置变量 `FS`，它代表字段分隔符，并且与你在 `awk` 命令中使用 `--field-separator` 设置的值相同，它只需执行一次，因此它包含在 `BEGIN` 语句中。
+
+#### awk 中的数组
+
+你已经知道如何通过使用 `$` 符号和字段编号来收集特定字段的值，但是在这种情况下，你需要将其存储在数组中而不是将其打印到终端。这是通过 `awk` 数组完成的。`awk` 数组的重要之处在于它包含键和值。 想象一下有关本文的内容；它看起来像这样：`author:"seth",title:"How to sort with awk",length:1200`。诸如作者、标题和长度之类的元素是键，跟着的内容为值。
+
+在排序的上下文中这样做的好处是，你可以将任何字段分配为键，将任何记录分配为值，然后使用内置的 `awk` 函数 `asorti()`（按索引排序）按键进行排序。现在，随便假设你*只*想按第二个字段排序。
+
+*没有*被特殊关键字 `BEGIN` 或 `END` 引起来的 `awk` 语句是在每个记录都要执行的循环。这是脚本的一部分，该脚本扫描数据中的模式并进行相应的处理。每次 `awk` 将注意力转移到一条记录上时，都会执行 `{}` 中的语句（除非以 `BEGIN` 或 `END` 开头）。
+
+要将键和值添加到数组，请创建一个包含数组的变量（在本示例脚本中，我将其称为 `ARRAY`，虽然不是很原汁原味，但很清楚），然后在方括号中分配给它键，用等号（`=`）连接值。
+
+```
+{ # dump each field into an array
+ ARRAY[$2] = $R;
+}
+```
+
+在此语句中，第二个字段的内容（`$2`）用作关键字，而当前记录（`$R`）用作值。
+
+### asorti() 函数
+
+除了数组之外，`awk` 还具有一些基本函数，你可以将它们用作常见任务的快速简便的解决方案。GNU awk中引入的函数之一 `asorti()` 提供了按键（*索引*）或值对数组进行排序的功能。
+
+你只能在对数组进行填充后对其进行排序，这意味着此操作不能对每个新记录都触发，而只能在脚本的最后阶段进行。为此，`awk` 提供了特殊的 `END` 关键字。与 `BEGIN` 相反，`END` 语句仅在扫描了所有记录之后才触发一次。
+
+将这些添加到你的脚本：
+
+```
+END {
+ asorti(ARRAY,SARRAY);
+ # get length
+ j = length(SARRAY);
+
+ for (i = 1; i <= j; i++) {
+ printf("%s %s\n", SARRAY[i],ARRAY[SARRAY[i]])
+ }
+}
+```
+
+`asorti()` 函数获取 `ARRAY` 的内容，按索引对其进行排序，然后将结果放入名为 `SARRAY` 的新数组（我在本文中发明的任意名称，表示“排序的 ARRAY”）。
+
+接下来，将变量 `j`（另一个任意名称）分配给 `length()` 函数的结果，该函数计算 `SARRAY` 中的项数。
+
+最后，使用 `for` 循环使用 `printf()` 函数遍历 `SARRAY` 中的每一项，以打印每个键，然后在 `ARRAY` 中打印该键的相应值。
+
+### 运行该脚本
+
+要运行你的 `awk` 脚本，先使其可执行：
+
+```
+$ chmod +x sorter.awk
+```
+
+然后针对 `penguin.list` 示例数据运行它：
+
+```
+$ ./sorter.awk penguins.list
+antipodes Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
+chrysocome Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
+demersus Spheniscus;demersus;Brisson;1760;African
+forsteri Aptenodytes;forsteri;Miller,JF;1778;Emperor
+linux Torvaldis;linux;Ewing,L;1996;Tux
+minor Eudyptula;minor;Bonaparte;1867;Little Blue
+papua Pygoscelis;papua;Wagler;1832;Gentoo
+```
+
+如你所见，数据按第二个字段排序。
+
+这有点限制。最好可以在运行时灵活选择要用作排序键的字段，以便可以在任何数据集上使用此脚本并获得有意义的结果。
+
+### 添加命令选项
+
+你可以通过在脚本中使用字面值 `var` 将命令变量添加到 `awk` 脚本中。更改脚本，以使迭代子句在创建数组时使用 `var`：
+
+```
+{ # dump each field into an array
+ ARRAY[$var] = $R;
+}
+```
+
+尝试运行该脚本，以便在执行脚本时使用 `-v var` 选项将其按第三字段排序：
+
+```
+$ ./sorter.awk -v var=3 penguins.list
+Bonaparte Eudyptula;minor;Bonaparte;1867;Little Blue
+Brisson Spheniscus;demersus;Brisson;1760;African
+Ewing,L Torvaldis;linux;Ewing,L;1996;Tux
+Miller,JF Aptenodytes;forsteri;Miller,JF;1778;Emperor
+Milne-Edwards Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
+Viellot Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
+Wagler Pygoscelis;papua;Wagler;1832;Gentoo
+```
+
+### 修正
+
+本文演示了如何在纯 GNU awk 中对数据进行排序。你可以对脚本进行改进，以便对你有用，花一些时间在`gawk` 的手册页上研究 [awk 函数][3]并自定义脚本以获得更好的输出。
+
+这是到目前为止的完整脚本：
+
+```
+#!/usr/bin/awk -f
+# GPLv3 appears here
+# usage: ./sorter.awk -v var=NUM FILE
+
+BEGIN { FS=";"; }
+
+{ # dump each field into an array
+ ARRAY[$var] = $R;
+}
+
+END {
+ asorti(ARRAY,SARRAY);
+ # get length
+ j = length(SARRAY);
+
+ for (i = 1; i <= j; i++) {
+ printf("%s %s\n", SARRAY[i],ARRAY[SARRAY[i]])
+ }
+}
+```
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/11/how-sort-awk
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/metrics_lead-steps-measure.png?itok=DG7rFZPk (Green graph of measurements)
+[2]: https://opensource.com/article/19/10/get-sorted-sort
+[3]: https://www.gnu.org/software/gawk/manual/html_node/Built_002din.html#Built_002din
diff --git a/translated/tech/20191114 Debugging Software Deployments with strace.md b/published/20191114 Debugging Software Deployments with strace.md
similarity index 72%
rename from translated/tech/20191114 Debugging Software Deployments with strace.md
rename to published/20191114 Debugging Software Deployments with strace.md
index ee3c54090d..c3557e89ef 100644
--- a/translated/tech/20191114 Debugging Software Deployments with strace.md
+++ b/published/20191114 Debugging Software Deployments with strace.md
@@ -1,8 +1,8 @@
[#]: collector: (lujun9972)
[#]: translator: (hanwckf)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11667-1.html)
[#]: subject: (Debugging Software Deployments with strace)
[#]: via: (https://theartofmachinery.com/2019/11/14/deployment_debugging_strace.html)
[#]: author: (Simon Arneaud https://theartofmachinery.com)
@@ -10,20 +10,20 @@
在软件部署中使用 strace 进行调试
======
-我的大部分工作都包括部署软件系统，这意味着我需要花费很多时间来解决以下问题：
+
- * 这个软件可以在原始开发者的机器上工作，但是为什么不能在我这里运行？
- * 这个软件昨天可以在我的机器上工作，但是为什么今天就不行？
+我的大部分工作都涉及到部署软件系统，这意味着我需要花费很多时间来解决以下问题：
+* 这个软件可以在原开发者的机器上工作，但是为什么不能在我这里运行？
+* 这个软件昨天可以在我的机器上工作，但是为什么今天就不行？
-
-这是调试的一种类型，但是与传统的软件调试有所不同。传统的调试通常只关心代码的逻辑，但是在软件部署中的调试关注的是程序的代码和它所在的运行环境之间的相互影响。即便问题的根源是代码的逻辑错误，但软件显然可以在别的机器上运行的事实意味着这类问题与运行环境密切相关。
+这是一种调试的类型，但是与一般的软件调试有所不同。一般的调试通常只关心代码的逻辑，但是在软件部署中的调试关注的是程序的代码和它所在的运行环境之间的相互影响。即便问题的根源是代码的逻辑错误，但软件显然可以在别的机器上运行的事实意味着这类问题与运行环境密切相关。
所以，在软件部署过程中，我没有使用传统的调试工具（例如 `gdb`），而是选择了其它工具进行调试。我最喜欢的用来解决“为什么这个软件无法在这台机器上运行？”这类问题的工具就是 `strace`。
-### 什么是 `strace`？
+### 什么是 strace？
-[`strace`][1] 是一个用来“追踪系统调用”的工具。它主要是一个 Linux 工具，但是你也可以在其它系统上使用类似的工具（例如 [DTrace][2] 和 [ktrace][3]）。
+[strace][1] 是一个用来“追踪系统调用”的工具。它主要是一个 Linux 工具，但是你也可以在其它系统上使用类似的工具（例如 [DTrace][2] 和 [ktrace][3]）。
它的基本用法非常简单。只需要在 `strace` 后面跟上你需要运行的命令，它就会显示出该命令触发的所有系统调用（你可能需要先安装好 `strace`）：
@@ -37,41 +37,39 @@ exit_group(0) = ?
+++ exited with 0 +++
```
-这些系统调用都是什么？他们就像是操作系统提供的 API。很久以前，软件拥有直接访问硬件的权限。如果软件需要在屏幕上显示一些东西，它将会与视频硬件的端口和内存映射寄存器纠缠不清。当多任务操作系统变得流行以后，这就导致了混乱的局面，因为不同的应用程序将“争夺”硬件，并且一个应用程序的错误可能致使其它应用程序崩溃，甚至导致整个系统崩溃。所以 CPUs 开始支持多种不同的特权模式 （或者称为“保护环”）。它们让操作系统内核在具有完全硬件访问权限的最高特权模式下运行，于此同时，其它在低特权模式下运行的应用程序必须通过向内核发起系统调用才能够与硬件进行交互。
+这些系统调用都是什么？它们就像是操作系统内核提供的 API。很久以前，软件拥有直接访问硬件的权限。如果软件需要在屏幕上显示一些东西，它将会与视频硬件的端口和内存映射寄存器纠缠不清。当多任务操作系统变得流行以后，这就导致了混乱的局面，因为不同的应用程序将“争夺”硬件，并且一个应用程序的错误可能致使其它应用程序崩溃，甚至导致整个系统崩溃。所以 CPU 开始支持多种不同的特权模式（或者称为“保护环”）。它们让操作系统内核在具有完全硬件访问权限的最高特权模式下运行，于此同时，其它在低特权模式下运行的应用程序必须通过向内核发起系统调用才能够与硬件进行交互。
在二进制级别上，发起系统调用相比简单的函数调用有一些区别，但是大部分程序都使用标准库提供的封装函数。例如，POSIX C 标准库包含一个 `write()` 函数，该函数包含用于进行 `write` 系统调用的所有与硬件体系结构相关的代码。
![][4]
-简单来说，一个应用程序与其环境（计算机系统）的相互影响都是通过系统调用来作用的。所以当软件在一台机器上可以工作但是在另一台机器无法工作的时候，追踪系统调用是一个很好的查错方法。具体地说，你可以通过追踪系统调用分析以下典型操作：
+简单来说，一个应用程序与其环境（计算机系统）的交互都是通过系统调用来完成的。所以当软件在一台机器上可以工作但是在另一台机器无法工作的时候，追踪系统调用是一个很好的查错方法。具体地说，你可以通过追踪系统调用分析以下典型操作：
* 控制台输入与输出 (IO)
* 网络 IO
* 文件系统访问以及文件 IO
- * 进程/线程 生命周期管理
+ * 进程/线程生命周期管理
* 原始内存管理
* 访问特定的设备驱动
-
-
-### 什么时候可以使用 `strace`？
+### 什么时候可以使用 strace？
理论上，`strace` 适用于任何用户空间程序，因为所有的用户空间程序都需要进行系统调用。`strace` 对于已编译的低级程序最有效果，但如果你可以避免运行时环境和解释器带来的大量额外输出，则仍然可以与 Python 等高级语言程序一起使用。
-当软件在一台机器上正常工作，但在另一台机器上却不能正常工作，同时抛出有关文件、权限或者不能运行某某命令等模糊的错误信息时，`strace` 往往能大显身手。不幸的是，它不能诊断高等级的问题，例如数字证书验证错误等。这些问题通常需要结合 `strace`（有时候是 [`ltrace`][5]），以及其它高级工具（例如使用 `openssl` 命令行工具调试数字证书错误）。
+当软件在一台机器上正常工作，但在另一台机器上却不能正常工作，同时抛出了有关文件、权限或者不能运行某某命令等模糊的错误信息时，`strace` 往往能大显身手。不幸的是，它不能诊断高等级的问题，例如数字证书验证错误等。这些问题通常需要组合使用 `strace`（有时候是 [`ltrace`][5]）和其它高级工具（例如使用 `openssl` 命令行工具调试数字证书错误）。
本文中的示例基于独立的服务器，但是对系统调用的追踪通常也可以在更复杂的部署平台上完成，仅需要找到合适的工具。
### 一个简单的例子
-假设你正在尝试运行一个叫做 foo 的服务器应用程序，但是发生了以下情况：
+假设你正在尝试运行一个叫做 `foo` 的服务器应用程序，但是发生了以下情况：
```
$ foo
Error opening configuration file: No such file or directory
```
-显然，它没有找到你已经写好的配置文件。之所以会发生这种情况，是因为包管理工具有时候在编译应用程序时指定了自定义的路径，所以你应当遵循特定发行版提供的安装指南。如果错误信息告诉你正确的配置文件应该在什么地方，你就可以在几秒钟内解决这个问题，但事实并非如此。你该如何找到正确的路径？
+显然，它没有找到你已经写好的配置文件。之所以会发生这种情况，是因为包管理工具有时候在编译应用程序时指定了自定义的路径，所以你应当遵循特定发行版提供的安装指南。如果错误信息告诉你正确的配置文件应该在什么地方，你就可以在几秒钟内解决这个问题，但如果没有告诉你呢？你该如何找到正确的路径？
如果你有权访问源代码，则可以通过阅读源代码来解决问题。这是一个好的备用计划，但不是最快的解决方案。你还可以使用类似 `gdb` 的单步调试器来观察程序的行为，但使用专门用于展示程序与系统环境交互作用的工具 `strace` 更加有效。
@@ -116,16 +114,14 @@ exit_group(1) = ?
+++ exited with 1 +++
```
-`strace` 输出的第一页通常是低级的进程启动过程。（你可以看到很多 `mmap`，`mprotect`，`brk` 调用，这是用来分配原始内存和映射动态链接库的。）实际上，在查找错误时，最好从下往上阅读 `strace` 的输出。你可以看到 `write` 调用在最后返回了错误信息。如果你努力了，你将会看到第一个失败的系统调用是 `openat`，它在尝试打开 `/etc/foo/config.json` 时抛出了 `ENOENT` (“No such file or directory”)的错误。现在我们已经知道了配置文件应该放在哪里。
+`strace` 输出的第一页通常是低级的进程启动过程。（你可以看到很多 `mmap`、`mprotect`、`brk` 调用，这是用来分配原始内存和映射动态链接库的。）实际上，在查找错误时，最好从下往上阅读 `strace` 的输出。你可以看到 `write` 调用在最后返回了错误信息。如果你向上找，你将会看到第一个失败的系统调用是 `openat`，它在尝试打开 `/etc/foo/config.json` 时抛出了 `ENOENT` (“No such file or directory”)的错误。现在我们已经知道了配置文件应该放在哪里。
这是一个简单的例子，但我敢说在 90% 的情况下，使用 `strace` 进行调试不需要更多复杂的工作。以下是完整的调试步骤：
- 1. 从程序中获得含糊不清的错误信息
- 2. 使用 `strace` 运行程序
- 3. 在输出中找到错误信息
- 4. 往前追溯并找到第一个失败的系统调用
-
-
+1. 从程序中获得含糊不清的错误信息
+2. 使用 `strace` 运行程序
+3. 在输出中找到错误信息
+4. 往前追溯并找到第一个失败的系统调用
第四步中的系统调用很可能向你显示出问题所在。
@@ -133,27 +129,27 @@ exit_group(1) = ?
在开始更加复杂的调试之前，这里有一些有用的调试技巧帮助你高效使用 `strace`：
-#### `man` 是你的朋友
+#### man 是你的朋友
在很多 *nix 操作系统中，你可以通过 `man syscalls` 查看系统调用的列表。你将会看到类似于 `brk(2)` 之类的东西，这意味着你可以通过运行 `man 2 brk` 得到与此相关的更多信息。
-一个小问题：`man 2 fork` 会显示出在 GNU `libc` 里封装的 `fork()` 手册页，而 `fork()` 现在实际上是由 `clone` 系统调用实现的。`fork` 的语义与 `clone` 相同，但是如果我写了一个含有 `fork()` 的程序并使用 `strace` 去调试它，我将找不到任何关于 `fork` 调用的信息，只能看到 `clone` 调用。只有在将源代码与 `strace` 的输出进行比较的时候，这种问题才会让人感到困惑。
+一个小问题：`man 2 fork` 会显示出在 GNU `libc` 里封装的 `fork()` 手册页，而 `fork()` 现在实际上是由 `clone` 系统调用实现的。`fork` 的语义与 `clone` 相同，但是如果我写了一个含有 `fork()` 的程序并使用 `strace` 去调试它，我将找不到任何关于 `fork` 调用的信息，只能看到 `clone` 调用。如果将源代码与 `strace` 的输出进行比较的时候，像这种问题会让人感到困惑。
-#### 使用 `-o` 将输出保存到文件
+#### 使用 -o 将输出保存到文件
-`strace` 可以生成很多输出，所以将输出保存到单独的文件是很有帮助的 （就像上面的例子一样）。它还能够在控制台中避免程序自身的输出与 `strace` 的输出发生混淆。
+`strace` 可以生成很多输出，所以将输出保存到单独的文件是很有帮助的（就像上面的例子一样）。它还能够在控制台中避免程序自身的输出与 `strace` 的输出发生混淆。
-#### 使用 `-s` 查看更多的参数
+#### 使用 -s 查看更多的参数
你可能已经注意到，错误信息的第二部分没有出现在上面的例子中。这是因为 `strace` 默认仅显示字符串参数的前 32 个字节。如果你需要捕获更多参数，请向 `strace` 追加类似于 `-s 128` 之类的参数。
-#### `-y` 使得追踪文件或套接字更加容易
+#### -y 使得追踪文件或套接字更加容易
“一切皆文件”意味着 *nix 系统通过文件描述符进行所有 IO 操作，不管是真实的文件还是通过网络或者进程间管道。这对于编程而言是很方便的，但是在追踪系统调用时，你将很难分辨出 `read` 和 `write` 的真实行为。
`-y` 参数使 `strace` 在注释中注明每个文件描述符的具体指向。
-#### 使用 `-p` 附加到正在运行的进程中
+#### 使用 -p 附加到正在运行的进程中
正如我们将在后面的例子中看到的，有时候你想追踪一个正在运行的程序。如果你知道这个程序的进程号为 1337 （可以通过 `ps` 查询），则可以这样操作：
@@ -164,15 +160,15 @@ $ strace -p 1337
你可能需要 root 权限才能运行。
-#### 使用 `-f` 追踪子进程
+#### 使用 -f 追踪子进程
`strace` 默认只追踪一个进程。如果这个进程产生了一个子进程，你将会看到创建子进程的系统调用（一般是 `clone`），但是你看不到子进程内触发的任何调用。
-如果你认为在子进程中存在 bug，则需要使用 `-f` 参数启用子进程追踪功能。这样做的缺点是输出的内容会让人更加困惑。当追踪一个进程时，`strace` 显示的是单个调用事件流。当追踪多个进程的时候，你将会看到以 `` 开始的初始调用，接着是一系列针对其它线程的调用，最后才出现以 `<... foocall resumed>` 结束的初始调用。此外，你可以使用 `-ff` 参数将所有的调用分离到不同的文件中（查看 [the `strace` manual][6] 获取更多信息）。
+如果你认为在子进程中存在错误，则需要使用 `-f` 参数启用子进程追踪功能。这样做的缺点是输出的内容会让人更加困惑。当追踪一个进程时，`strace` 显示的是单个调用事件流。当追踪多个进程的时候，你将会看到以 `` 开始的初始调用，接着是一系列针对其它线程的调用，最后才出现以 `<... foocall resumed>` 结束的初始调用。此外，你可以使用 `-ff` 参数将所有的调用分离到不同的文件中（查看 [strace 手册][6] 获取更多信息）。
-#### 使用 `-e` 进行过滤
+#### 使用 -e 进行过滤
-正如你所看到的，默认的追踪输出是所有的系统调用。你可以使用 `-e` 参数过滤你需要追踪的调用（查看 [the `strace` manual][6]）。这样做的好处是运行过滤后的 `strace` 比起使用 `grep` 进行二次过滤要更快。老实说，我大部分时间都不会被打扰。
+正如你所看到的，默认的追踪输出是所有的系统调用。你可以使用 `-e` 参数过滤你需要追踪的调用（查看 [strace 手册][6]）。这样做的好处是运行过滤后的 `strace` 比起使用 `grep` 进行二次过滤要更快。老实说，我大部分时间都不会被打扰。
#### 并非所有的错误都是不好的
@@ -187,17 +183,17 @@ stat("/usr/bin/uname", {st_mode=S_IFREG|0755, st_size=39584, ...}) = 0
...
```
-“错误信息之前的最后一次失败调用”这种启发式方法非常适合于查找错误。无论如何，自下而上地工作是有道理的。
+“错误信息之前的最后一次失败调用”这种启发式方法非常适合于查找错误。无论如何，自下而上地查找是有道理的。
-#### C编程指南非常有助于理解系统调用
+#### C 编程指南非常有助于理解系统调用
-标准 C 库函数调用不属于系统调用，但它们仅是系统调用之上的唯一一个薄层。所以如果你了解（甚至只是略知一二）如何使用 C 语言，那么阅读系统调用追踪信息就非常容易。例如，如果你在调试网络系统调用，你可以尝试略读 [Beej’s classic Guide to Network Programming][7]。
+标准 C 库函数调用不属于系统调用，但它们仅是系统调用之上的唯一一个薄层。所以如果你了解（甚至只是略知一二）如何使用 C 语言，那么阅读系统调用追踪信息就非常容易。例如，如果你在调试网络系统调用，你可以尝试略读 [Beej 经典的《网络编程指南》][7]。
### 一个更复杂的调试例子
-就像我说的那样，简单的调试例子代表我在大部分情况下如何使用 `strace` 。然而，有时候需要一些更加细致的工作，所以这里有一个稍微复杂（且真实）的例子。
+就像我说的那样，简单的调试例子表现了我在大部分情况下如何使用 `strace`。然而，有时候需要一些更加细致的工作，所以这里有一个稍微复杂（且真实）的例子。
-[`bcron`][8] 是一个任务调度器，它是经典 *nix `cron` 守护程序的一种实现。它已经被安装到一台服务器上，但是当有人尝试编辑作业时间表时，发生了以下情况：
+[bcron][8] 是一个任务调度器，它是经典 *nix `cron` 守护程序的另一种实现。它已经被安装到一台服务器上，但是当有人尝试编辑作业时间表时，发生了以下情况：
```
# crontab -e -u logs
@@ -232,9 +228,9 @@ exit_group(111) = ?
在程序结束之前有一个 `write` 的错误信息，但是这次有些不同。首先，在此之前没有任何相关的失败系统调用。其次，我们看到这个错误信息是由 `read` 从别的地方读取而来的。这看起来像是真正的错误发生在别的地方，而 `bcrontab` 只是在转播这些信息。
-如果你查阅了 `man 2 read`，你将会看到 `read` 的第三个参数 (3) 代表文件描述符，这是 *nix 操作系统用于所有 IO 操作的句柄。你该如何知道文件描述符 3 代表什么？在这种情况下，你可以使用 `-y` 参数运行 `strace`（如上文所述），它将会在注释里告诉你文件描述符的具体指向，但是了解如何从上面这种输出中分析追踪结果是很有用的。
+如果你查阅了 `man 2 read`，你将会看到 `read` 的第一个参数 (`3`) 是一个文件描述符，这是 *nix 操作系统用于所有 IO 操作的句柄。你该如何知道文件描述符 3 代表什么？在这种情况下，你可以使用 `-y` 参数运行 `strace`（如上文所述），它将会在注释里告诉你文件描述符的具体指向，但是了解如何从上面这种输出中分析追踪结果是很有用的。
-一个文件描述符可以来自于许多系统调用之一（这取决于它是用于控制台、网络套接字还是真实文件等的描述符），但不论如何，我们都可以搜索返回值为 3 的系统调用（例如，在 `strace` 的输出中查找 “=3”）。在这次 `strace` 中可以看到有两个这样的调用：最上面的 `openat` 以及中间的 `socket`。`openat` 打开一个文件，但是紧接着的 `close(3)` 表明其已经被关闭。（注意：文件描述符可以在打开并关闭后重复使用。）所以 `socket` 调用才是与此相关的（它是在 `read` 之前的最后一次），这告诉我们 `brcontab` 正在与一个网络套接字通信。在下一行，`connect` 表明文件描述符 3 是一个连接到 `/var/run/bcron-spool` 的 Unix 域套接字。
+一个文件描述符可以来自于许多系统调用之一（这取决于它是用于控制台、网络套接字还是真实文件等的描述符），但不论如何，我们都可以搜索返回值为 `3` 的系统调用（例如，在 `strace` 的输出中查找 `=3`）。在这次 `strace` 中可以看到有两个这样的调用：最上面的 `openat` 以及中间的 `socket`。`openat` 打开一个文件，但是紧接着的 `close(3)` 表明其已经被关闭。（注意：文件描述符可以在打开并关闭后重复使用。）所以 `socket` 调用才是与此相关的（它是在 `read` 之前的最后一个），这告诉我们 `brcontab` 正在与一个网络套接字通信。在下一行，`connect` 表明文件描述符 3 是一个连接到 `/var/run/bcron-spool` 的 Unix 域套接字。
因此，我们需要弄清楚 Unix 套接字的另一侧是哪个进程在监听。有两个巧妙的技巧适用于在服务器部署中调试。一个是使用 `netstat` 或者较新的 `ss`。这两个命令都描述了当前系统中活跃的网络套接字，使用 `-l` 参数可以显示出处于监听状态的套接字，而使用 `-p` 参数可以得到正在使用该套接字的程序信息。（它们还有更多有用的选项，但是这两个已经足够完成工作了。）
@@ -243,7 +239,7 @@ exit_group(111) = ?
u_str LISTEN 0 128 /var/run/bcron-spool 1466637 * 0 users:(("unixserver",pid=20629,fd=3))
```
-这告诉我们 `/var/run/bcron-spool` 套接字的监听程序是 `unixserver` 这个命令，它的进程 ID 为 20629。（巧合的是，这个程序也使用文件描述符 3 去连接这个套接字。）
+这告诉我们 `/var/run/bcron-spool` 套接字的监听程序是 `unixserver` 这个命令，它的进程 ID 为 20629。（巧合的是，这个程序也使用文件描述符 `3` 去连接这个套接字。）
第二个常用的工具就是使用 `lsof` 查找相同的信息。它可以列出当前系统中打开的所有文件（或文件描述符）。或者，我们可以得到一个具体文件的信息：
@@ -277,7 +273,7 @@ rt_sigreturn({mask=[]}) = 43
accept(3, NULL, NULL
```
-（最后一个 `accept` 调用没有在追踪周期里完成。）不幸的是，这次追踪没有包含我们想要的错误信息。我们没有观察到 `bcrontan` 往套接字发送或接受的任何信息。然而，我们看到了很多进程管理操作（`clone`，`wait4`，`SIGCHLD`，等等）。这个进程产生了子进程，我们猜测真实的工作是由子进程完成的。如果我们想捕获子进程的追踪信息，就必须往 `strace` 追加 `-f` 参数。以下是我们最终使用 `strace -f -o /tmp/trace -p 20629` 找到的错误信息：
+（最后一个 `accept` 调用没有在追踪期间完成。）不幸的是，这次追踪没有包含我们想要的错误信息。我们没有观察到 `bcrontan` 往套接字发送或接受的任何信息。然而，我们看到了很多进程管理操作（`clone`、`wait4`、`SIGCHLD`，等等）。这个进程产生了子进程，我们猜测真实的工作是由子进程完成的。如果我们想捕获子进程的追踪信息，就必须往 `strace` 追加 `-f` 参数。以下是我们最终使用 `strace -f -o /tmp/trace -p 20629` 找到的错误信息：
```
21470 openat(AT_FDCWD, "tmp/spool.21470.1573692319.854640", O_RDWR|O_CREAT|O_EXCL, 0600) = -1 EACCES (Permission denied)
@@ -305,7 +301,9 @@ accept(3, NULL, NULL
21470 +++ exited with 111 +++
```
-（如果你在这里失败了，你可能需要阅读 [我之前有关 *nix 进程管理和 shell 的文章][9]）好的，现在 PID 为 20629 的服务器进程没有权限在 `/var/spool/cron/tmp/spool.21470.1573692319.854640` 创建文件。最可能的原因就是典型的 *nix 文件系统权限设置。让我们检查一下：
+（如果你在这里迷糊了，你可能需要阅读 [我之前有关 \*nix 进程管理和 shell 的文章][9]）
+
+现在 PID 为 20629 的服务器进程没有权限在 `/var/spool/cron/tmp/spool.21470.1573692319.854640` 创建文件。最可能的原因就是典型的 *nix 文件系统权限设置。让我们检查一下：
```
# ls -ld /var/spool/cron/tmp/
@@ -330,7 +328,7 @@ via: https://theartofmachinery.com/2019/11/14/deployment_debugging_strace.html
作者：[Simon Arneaud][a]
选题：[lujun9972][b]
译者：[hanwckf](https://github.com/hanwckf)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/published/20191115 How to port an awk script to Python.md b/published/20191115 How to port an awk script to Python.md
new file mode 100644
index 0000000000..f163b2db42
--- /dev/null
+++ b/published/20191115 How to port an awk script to Python.md
@@ -0,0 +1,201 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11654-1.html)
+[#]: subject: (How to port an awk script to Python)
+[#]: via: (https://opensource.com/article/19/11/awk-to-python)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+如何把 awk 脚本移植到 Python
+======
+
+> 将一个 awk 脚本移植到 Python 主要在于代码风格而不是转译。
+
+
+
+脚本是解决问题的有效方法，而 awk 是编写脚本的出色语言。它特别擅长于简单的文本处理，它可以带你完成配置文件的某些复杂重写或目录中文件名的重新格式化。
+
+### 何时从 awk 转向 Python
+
+但是在某些方面，awk 的限制开始显现出来。它没有将文件分解为模块的真正概念，它缺乏质量错误报告，并且缺少了现在被认为是编程语言工作原理的其他内容。当编程语言的这些丰富功能有助于维护关键脚本时，移植将是一个不错的选择。
+
+我最喜欢的完美移植 awk 的现代编程语言是 Python。
+
+在将 awk 脚本移植到 Python 之前，通常值得考虑一下其原始使用场景。例如，由于 awk 的局限性，通常从 Bash 脚本调用 awk 代码，其中包括一些对 `sed`、`sort` 之类的其它命令行常见工具的调用。 最好将所有内容转换为一个一致的 Python 程序。有时，脚本会做出过于宽泛的假设，例如，即使实际上只运行一个文件，该代码也可能允许任意数量的文件。
+
+在仔细考虑了上下文并确定了要用 Python 替代的东西之后，该编写代码了。
+
+### 标准 awk 到 Python 功能
+
+以下 Python 功能是有用的，需要记住：
+
+```
+with open(some_file_name) as fpin:
+ for line in fpin:
+ pass # do something with line
+```
+
+此代码将逐行循环遍历文件并处理这些行。
+
+如果要访问行号（相当于 awk 的 `NR`），则可以使用以下代码：
+
+```
+with open(some_file_name) as fpin:
+ for nr, line in enumerate(fpin):
+ pass # do something with line
+```
+
+### 在 Python 中实现多文件的 awk 式行为
+
+如果你需要能够遍历任意数量的文件同时保持行数的持续计数（类似 awk 的 `FNR`），则此循环可以做到这一点：
+
+```
+def awk_like_lines(list_of_file_names):
+ def _all_lines():
+ for filename in list_of_file_names:
+ with open(filename) as fpin:
+ yield from fpin
+ yield from enumerate(_all_lines())
+```
+
+此语法使用 Python 的*生成器*和 `yield from` 来构建*迭代器*，该迭代器将遍历所有行并保持一个持久计数。
+
+如果你需要同时使用 `FNR` 和 `NR`，这是一个更复杂的循环：
+
+```
+def awk_like_lines(list_of_file_names):
+ def _all_lines():
+ for filename in list_of_file_names:
+ with open(filename) as fpin:
+ yield from enumerate(fpin)
+ for nr, (fnr, line) in _all_lines:
+ yield nr, fnr, line
+```
+
+### 更复杂的 FNR、NR 和行数的 awk 行为
+
+如果 `FNR`、`NR` 和行数这三个你全都需要，仍然会有一些问题。如果确实如此，则使用三元组（其中两个项目是数字）会导致混淆。命名参数可使该代码更易于阅读，因此最好使用 `dataclass`：
+
+```
+import dataclass
+
+@dataclass.dataclass(frozen=True)
+class AwkLikeLine:
+ content: str
+ fnr: int
+ nr: int
+
+def awk_like_lines(list_of_file_names):
+ def _all_lines():
+ for filename in list_of_file_names:
+ with open(filename) as fpin:
+ yield from enumerate(fpin)
+ for nr, (fnr, line) in _all_lines:
+ yield AwkLikeLine(nr=nr, fnr=fnr, line=line)
+```
+
+你可能想知道，为什么不一直用这种方法呢？使用其它方式的的原因是总用这种方法太复杂了。如果你的目标是把一个通用库更容易地从 awk 移植到 Python，请考虑这样做。但是编写一个可以使你确切地了解特定情况所需的循环的方法通常更容易实现，也更容易理解（因而易于维护）。
+
+### 理解 awk 字段
+
+一旦有了与一行相对应的字符串，如果要转换 awk 程序，则通常需要将其分解为*字段*。Python 有几种方法可以做到这一点。这将把行按任意数量的连续空格拆分，返回一个字符串列表：
+
+```
+line.split()
+```
+
+如果需要另一个字段分隔符，比如以 `:` 分隔行，则需要 `rstrip` 方法来删除最后一个换行符：
+
+```
+line.rstrip("\n").split(":")
+```
+
+完成以下操作后，列表 `parts` 将存有分解的字符串：
+
+```
+parts = line.rstrip("\n").split(":")
+```
+
+这种拆分非常适合用来处理参数，但是我们处于[偏差一个的错误][2]场景中。现在 `parts[0]` 将对应于 awk 的 `$1`，`parts[1]` 将对应于 awk 的 `$2`，依此类推。之所以偏差一个，是因为 awk 计数“字段”从 1 开始，而 Python 从 0 开始计数。在 awk 中，`$0` 是整个行 —— 等同于 `line.rstrip("\n")`，而 awk 的 `NF`（字段数）更容易以 `len(parts)` 的形式得到。
+
+### 移植 awk 字段到 Python
+
+例如，让我们将这个单行代码“[如何使用 awk 从文件中删除重复行][3]”转换为 Python。
+
+`awk` 中的原始代码是：
+
+```
+awk '!visited[$0]++' your_file > deduplicated_file
+```
+
+“真实的” Python 转换将是：
+
+```
+import collections
+import sys
+
+visited = collections.defaultdict(int)
+for line in open("your_file"):
+ did_visit = visited[line]
+ visited[line] += 1
+ if not did_visit:
+ sys.stdout.write(line)
+```
+
+但是，Python 比 awk 具有更多的数据结构。与其计数访问次数（除了知道是否看到一行，我们不使用它），为什么不记录访问的行呢？
+
+```
+import sys
+
+visited = set()
+for line in open("your_file"):
+ if line in visited:
+ continue
+ visited.add(line)
+ sys.stdout.write(line)
+```
+
+### 编写 Python 化的 awk 代码
+
+Python 社区提倡编写 Python 化的代码，这意味着它要遵循公认的代码风格。更加 Python 化的方法将区分*唯一性*和输入/输出的关注点。此更改将使对代码进行单元测试更加容易：
+
+```
+def unique_generator(things):
+ visited = set()
+ for thing in things:
+ if thing in visited:
+ continue
+ visited.add(things)
+ yield thing
+
+import sys
+
+for line in unique_generator(open("your_file")):
+ sys.stdout.write(line)
+```
+
+将所有逻辑置于输入/输出代码之外，可以更好地分离问题，并提高代码的可用性和可测试性。
+
+### 结论：Python 可能是一个不错的选择
+
+将 awk 脚本移植到 Python 时，通常是在考虑适当的 Python 代码风格时重新实现核心需求，而不是按条件/操作进行笨拙的音译。考虑原始上下文并产生高质量的 Python 解决方案。虽然有时候使用 awk 的 Bash 单行代码可以完成这项工作，但 Python 编码是通往更易于维护的代码的途径。
+
+另外，如果你正在编写 awk 脚本，我相信您也可以学习 Python！如果你有任何疑问，请告诉我。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/11/awk-to-python
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_women_computing_4.png?itok=VGZO8CxT (Woman sitting in front of her laptop)
+[2]: https://en.wikipedia.org/wiki/Off-by-one_error
+[3]: https://opensource.com/article/19/10/remove-duplicate-lines-files-awk
diff --git a/translated/tech/20191116 6 Methods to Quickly Check if a Website is up or down from the Linux Terminal.md b/published/20191116 6 Methods to Quickly Check if a Website is up or down from the Linux Terminal.md
similarity index 70%
rename from translated/tech/20191116 6 Methods to Quickly Check if a Website is up or down from the Linux Terminal.md
rename to published/20191116 6 Methods to Quickly Check if a Website is up or down from the Linux Terminal.md
index 39e12ca4a3..222e24b4c7 100644
--- a/translated/tech/20191116 6 Methods to Quickly Check if a Website is up or down from the Linux Terminal.md
+++ b/published/20191116 6 Methods to Quickly Check if a Website is up or down from the Linux Terminal.md
@@ -1,24 +1,26 @@
[#]: collector: (lujun9972)
[#]: translator: (lxbwolf)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11661-1.html)
[#]: subject: (6 Methods to Quickly Check if a Website is up or down from the Linux Terminal)
[#]: via: (https://www.2daygeek.com/linux-command-check-website-is-up-down-alive/)
[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
-在 Linux Terminal 快速检测网站是否宕机的 6 个方法
+在 Linux 终端快速检测网站是否宕机的 6 个方法
======
-本教程教你怎样在 Linux terminal 快速检测一个网站是否宕机。
+> 本教程教你怎样在 Linux 终端快速检测一个网站是否宕机。
-你可能已经了解了一些类似的命令，像 ping，curl 和 wget。我们在本教程中又加入了一些其他命令。同时，对于要检测单个和多个主机的信息我们也加入了不同的选项。
+
-本文将帮助你检测网站是否宕机。但是如果你在维护一个网站，希望网站宕掉时得到实时的报警，我推荐你去使用实时网站监控工具。这种工具有很多，有些是免费的，大部分收费。根据你的需求，选择合适的工具。在后续的文章中我们会涉及这个主题。
+你可能已经了解了一些类似的命令，像 `ping`、`curl` 和 `wget`。我们在本教程中又加入了一些其他命令。同时，我们也加入了不同的选项来检测单个和多个主机的信息。
+
+本文将帮助你检测网站是否宕机。但是如果你在维护一些网站，希望网站宕掉时得到实时的报警，我推荐你去使用实时网站监控工具。这种工具有很多，有些是免费的，大部分收费。根据你的需求，选择合适的工具。在后续的文章中我们会涉及这个主题。
### 方法 1：使用 fping 命令检测一个网站是否宕机
-**[fping 命令][1]** 是一个类似 ping 的程序，使用互联网控制消息协议回应请求报文（ICMP echo request）来判断目标主机是否能回应。fping 与 ping 的不同之处在于它可以并行地 ping 任意数量的主机，也可以从一个文本文件读入主机。fping 发送一个 ICMP echo request 后不等待目标主机响应，就以 round-robin 模式向下一个目标主机发请求。如果一个目标主机有响应，那么它就被标记为存活的（active）然后从检查目标列表里去掉。如果一个目标主机在限定的时间和（或）重试次数内没有响应，则被指定为网站无法到达（unreachable）。
+[fping 命令][1] 是一个类似 `ping` 的程序，使用互联网控制消息协议（ICMP）的回应请求报文来判断目标主机是否能回应。`fping` 与 `ping` 的不同之处在于它可以并行地 `ping` 任意数量的主机，也可以从一个文本文件读入主机名称。`fping` 发送一个 ICMP 回应请求后不等待目标主机响应，就以轮询模式向下一个目标主机发请求。如果一个目标主机有响应，那么它就被标记为存活的，然后从检查目标列表里去掉。如果一个目标主机在限定的时间和（或）重试次数内没有响应，则被指定为网站无法到达的。
```
# fping 2daygeek.com linuxtechnews.com magesh.co.in
@@ -30,7 +32,7 @@ magesh.co.in is alive
### 方法 2：使用 http 命令检测一个网站是否宕机
-HTTPie（读作 aitch-tee-tee-pie）是一个命令行 HTTP 客户端。**[httpie tool][2]** 是一个可以与 web 服务通过 CLI（command-line interface）进行交互的现代工具。httpie tool 提供了简单的 http 命令，可以通过发送简单的、自然语言语法的任意 HTTP 请求得到多彩的结果输出。HTTPie 可以用来对 HTTP 服务器进行测试、调试和基本的交互。
+HTTPie（读作 aitch-tee-tee-pie）是一个命令行 HTTP 客户端。[httpie][2] 是一个可以与 web 服务通过 CLI 进行交互的现代工具。httpie 工具提供了简单的 `http` 命令，可以通过发送简单的、自然语言语法的任意 HTTP 请求得到多彩的结果输出。HTTPie 可以用来对 HTTP 服务器进行测试、调试和基本的交互。
```
# http 2daygeek.com
@@ -49,7 +51,7 @@ Vary: Accept-Encoding
### 方法 3：使用 curl 命令检测一个网站是否宕机
-**[curl 命令](https://www.2daygeek.com/curl-linux-command-line-download-manager/)** 是一个用于在服务器间通过支持的协议（DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, TELNET 和 TFTP）传输数据的工具。这个工具不支持用户交互。curl 也支持使用代理、用户认证、FTP 上传、HTTP post、SSL 连接、cookies、断点续传、Metalink等等。curl 由 libcurl 库提供所有与传输有关的能力。
+[curl 命令][3] 是一个用于在服务器间通过支持的协议（DICT、FILE、FTP、FTPS、GOPHER、HTTP、HTTPS、IMAP、IMAPS、LDAP、LDAPS、POP3、POP3S、RTMP、RTSP、SCP、SFTP、SMTP、SMTPS、TELNET 和 TFTP）传输数据的工具。这个工具不支持用户交互。`curl` 也支持使用代理、用户认证、FTP 上传、HTTP POST 请求、SSL 连接、cookie、断点续传、Metalink 等等。`curl `由 libcurl 库提供所有与传输有关的能力。
```
# curl -I https://www.magesh.co.in
@@ -67,7 +69,7 @@ server: cloudflare
cf-ray: 535b74123ca4dbf3-LHR
```
-如果你只想看 HTTP 状态码而不是返回的全部信息，用下面的 curl 命令：
+如果你只想看 HTTP 状态码而不是返回的全部信息，用下面的 `curl` 命令：
```
# curl -I "www.magesh.co.in" 2>&1 | awk '/HTTP\// {print $2}'
@@ -87,7 +89,7 @@ else
fi
```
-当你把脚本内容添加到一个文件后，执行文件，查看结果
+当你把脚本内容添加到一个文件后，执行文件，查看结果：
```
# sh curl-url-check.sh
@@ -113,7 +115,7 @@ echo "----------------------------------"
done
```
-当你把上面脚本内容添加到一个文件后，执行文件，查看结果
+当你把上面脚本内容添加到一个文件后，执行文件，查看结果：
```
# sh curl-url-check-1.sh
@@ -130,7 +132,7 @@ www.xyzzz.com is down
### 方法 4：使用 wget 命令检测一个网站是否宕机
-**[wget 命令][4]** （前身是 Geturl）是一个免费的开源命令行下载工具，通过 HTTP、HTTPS、FTP和其他广泛使用的互联网协议检索文件。wget 是非交互式的命令行工具，由 World Wide Web 和 get 得名。wget 相对于其他工具来说更优秀，功能包括后台运行、递归下载、多文件下载、断点续传、非交互式下载和大文件下载。
+[wget 命令][4]（前身是 Geturl）是一个自由开源的命令行下载工具，通过 HTTP、HTTPS、FTP 和其他广泛使用的互联网协议获取文件。`wget` 是非交互式的命令行工具，由 World Wide Web 和 get 得名。`wget` 相对于其他工具来说更优秀，功能包括后台运行、递归下载、多文件下载、断点续传、非交互式下载和大文件下载。
```
# wget -S --spider https://www.magesh.co.in
@@ -158,7 +160,7 @@ Remote file exists and could contain further links,
but recursion is disabled -- not retrieving.
```
-如果你只想看 HTTP 状态码而不是返回的全部结果，用下面的 wget 命令：
+如果你只想看 HTTP 状态码而不是返回的全部结果，用下面的 `wget` 命令：
```
# wget --spider -S "www.magesh.co.in" 2>&1 | awk '/HTTP\// {print $2}'
@@ -178,7 +180,7 @@ else
fi
```
-当你把脚本内容添加到一个文件后，执行文件，查看结果
+当你把脚本内容添加到一个文件后，执行文件，查看结果：
```
# wget-url-check.sh
@@ -221,7 +223,7 @@ www.xyzzz.com is down
### 方法 5：使用 lynx 命令检测一个网站是否宕机
-**[lynx][5]** 是一个在可寻址光标字符单元终端上使用的基于文本的高度可配的 web 浏览器，它是最古老的 web 浏览器并且现在仍在开发。
+[lynx][5] 是一个在可寻址光标字符单元终端上使用的基于文本的高度可配的 web 浏览器，它是最古老的 web 浏览器并且现在仍在活跃开发。
```
# lynx -head -dump http://www.magesh.co.in
@@ -240,7 +242,7 @@ Server: cloudflare
CF-RAY: 535fc5704a43e694-LHR
```
-如果你只想看 HTTP 状态码而不是返回的全部结果，用下面的 lynx 命令：
+如果你只想看 HTTP 状态码而不是返回的全部结果，用下面的 `lynx` 命令：
```
# lynx -head -dump https://www.magesh.co.in 2>&1 | awk '/HTTP\// {print $2}'
@@ -260,7 +262,7 @@ else
fi
```
-当你把脚本内容添加到一个文件后，执行文件，查看结果
+当你把脚本内容添加到一个文件后，执行文件，查看结果：
```
# sh lynx-url-check.sh
@@ -303,7 +305,7 @@ www.xyzzz.com is down
### 方法 6：使用 ping 命令检测一个网站是否宕机
-**[ping 命令][1]** （Packet Internet Groper）是网络工具的代表，用于在互联网协议（IP）的网络中测试一个目标主机是否可用/可连接。通过向目标主机发送 ICMP 回应请求报文包并等待 ICMP 回应响应报文来检测主机的可用性。它基于已发送的包、接收到的包和丢失了的包来统计结果数据，通常包含最小/平均/最大响应时间。
+[ping 命令][1]（Packet Internet Groper）是网络工具的代表，用于在互联网协议（IP）的网络中测试一个目标主机是否可用/可连接。通过向目标主机发送 ICMP 回应请求报文包并等待 ICMP 回应响应报文来检测主机的可用性。它基于已发送的包、接收到的包和丢失了的包来统计结果数据，通常包含最小/平均/最大响应时间。
```
# ping -c 5 2daygeek.com
@@ -320,9 +322,9 @@ PING 2daygeek.com (104.27.157.177) 56(84) bytes of data.
rtt min/avg/max/mdev = 170.668/213.824/250.295/28.320 ms
```
-### 方法 7：使用 telnet 命令检测一个网站是否宕机
+### 附加 1：使用 telnet 命令检测一个网站是否宕机
-telnet 命令是一个使用 TELNET 协议用于 TCP/IP 网络中多个主机相互通信的古老的网络协议。它通过 23 端口连接其他设备如计算机和网络设备。telnet 是不安全的协议，现在由于用这个协议发送的数据没有经过加密可能被黑客拦截，所以不推荐使用。大家都使用经过加密且非常安全的 SSH 协议来代替 telnet。
+`telnet` 命令是一个使用 TELNET 协议用于 TCP/IP 网络中多个主机相互通信的古老的网络协议。它通过 23 端口连接其他设备如计算机和网络设备。`telnet` 是不安全的协议，现在由于用这个协议发送的数据没有经过加密可能被黑客拦截，所以不推荐使用。大家都使用经过加密且非常安全的 SSH 协议来代替 `telnet`。
```
# telnet google.com 80
@@ -335,11 +337,11 @@ telnet> quit
Connection closed.
```
-### 方法 8：使用 bash 脚本检测一个网站是否宕机
+### 附加 2：使用 bash 脚本检测一个网站是否宕机
-简而言之，一个 **[shell 脚本][6]** 就是一个包含一系列命令的文件。shell 从文件读取内容按输入顺序逐行在命令行执行。为了让它更有效，我们添加一些条件。这也减轻了 Linux 管理员的负担。
+简而言之，一个 [shell 脚本][6] 就是一个包含一系列命令的文件。shell 从文件读取内容按输入顺序逐行在命令行执行。为了让它更有效，我们添加一些条件。这也减轻了 Linux 管理员的负担。
-如果你想想用 wget 命令看多个网站的状态，使用下面的 shell 脚本：
+如果你想想用 `wget` 命令看多个网站的状态，使用下面的 shell 脚本：
```
# vi wget-url-check-2.sh
@@ -365,7 +367,7 @@ google.co.in is up
www.xyzzz.com is down
```
-如果你想想用 wget 命令看多个网站的状态，使用下面的 **[shell 脚本][7]**：
+如果你想用 `wget` 命令看多个网站的状态，使用下面的 [shell 脚本][7]：
```
# vi curl-url-check-2.sh
@@ -398,7 +400,7 @@ via: https://www.2daygeek.com/linux-command-check-website-is-up-down-alive/
作者：[Magesh Maruthamuthu][a]
选题：[lujun9972][b]
译者：[lxbwolf](https://github.com/lxbwolf)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/published/20191118 How internet security works- TLS, SSL, and CA.md b/published/20191118 How internet security works- TLS, SSL, and CA.md
new file mode 100644
index 0000000000..144fe836e8
--- /dev/null
+++ b/published/20191118 How internet security works- TLS, SSL, and CA.md
@@ -0,0 +1,136 @@
+[#]: collector: (lujun9972)
+[#]: translator: (hopefully2333)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11699-1.html)
+[#]: subject: (How internet security works: TLS, SSL, and CA)
+[#]: via: (https://opensource.com/article/19/11/internet-security-tls-ssl-certificate-authority)
+[#]: author: (Bryant Son https://opensource.com/users/brson)
+
+互联网的安全是如何保证的：TLS、SSL 和 CA
+======
+
+> 你的浏览器里的锁的图标的后面是什么？
+
+![Lock][1]
+
+每天你都会重复这件事很多次，访问网站，网站需要你用你的用户名或者电子邮件地址和你的密码来进行登录。银行网站、社交网站、电子邮件服务、电子商务网站和新闻网站。这里只在使用了这种机制的网站中列举了其中一小部分。
+
+每次你登录进一个这种类型的网站时，你实际上是在说：“是的，我信任这个网站，所以我愿意把我的个人信息共享给它。”这些数据可能包含你的姓名、性别、实际地址、电子邮箱地址，有时候甚至会包括你的信用卡信息。
+
+但是你怎么知道你可以信任这个网站？换个方式问，为了让你可以信任它，网站应该如何保护你的交易？
+
+本文旨在阐述使网站变得安全的机制。我会首先论述 web 协议 http 和 https，以及传输层安全（TLS）的概念，后者是互联网协议（IP）层中的加密协议之一。然后，我会解释证书颁发机构和自签名证书，以及它们如何帮助保护一个网站。最后，我会介绍一些开源的工具，你可以使用它们来创建和管理你的证书。
+
+### 通过 https 保护路由
+
+了解一个受保护的网站的最简单的方式就是在交互中观察它，幸运的是，在今天的互联网上，发现一个安全的网站远远比找到一个不安全的网站要简单。但是，因为你已经在 Opensource.com 这个网站上了，我会使用它来作为案例，无论你使用的是哪个浏览器，你应该在你的地址栏旁边看到一个像锁一样的图标。点击这个锁图标，你应该会看见一些和下面这个类似的东西。
+
+![Certificate information][2]
+
+默认情况下，如果一个网站使用的是 http 协议，那么它是不安全的。为通过网站主机的路由添加一个配置过的证书，可以把这个网站从一个不安全的 http 网站变为一个安全的 https 网站。那个锁图标通常表示这个网站是受 https 保护的。
+
+点击证书来查看网站的 CA，根据你的浏览器，你可能需要下载证书来查看它。
+
+![Certificate information][3]
+
+在这里，你可以了解有关 Opensource.com 证书的信息。例如，你可以看到 CA 是 DigiCert，并以 Opensource.com 的名称提供给 Red Hat。
+
+这个证书信息可以让终端用户检查该网站是否可以安全访问。
+
+> 警告：如果你没有在网站上看到证书标志，或者如果你看见的标志显示这个网站不安全——请不要登录或者做任何需要你个人数据的操作。这种情况非常危险！
+
+如果你看到的是警告标志，对于大多数面向公众开放的网站来说，这很少见，它通常意味着该证书已经过期或者是该证书是自签名的，而非通过一个受信任的第三方来颁发。在我们进入这些主题之前，我想解释一下 TLS 和 SSL。
+
+### 带有 TLS 和 SSL 的互联网协议
+
+TLS 是旧版安全套接字层协议（SSL）的最新版本。理解这一点的最好方法就是仔细理解互联网协议的不同协议层。
+
+![IP layers][4]
+
+我们知道当今的互联网是由 6 个层面组成的：物理层、数据链路层、网络层、传输层、安全层、应用层。物理层是基础，这一层是最接近实际的硬件设备的。应用层是最抽象的一层，是最接近终端用户的一层。安全层可以被认为是应用层的一部分，TLS 和 SSL，是被设计用来在一个计算机网络中提供通信安全的加密协议，它们位于安全层中。
+
+这个过程可以确保终端用户使用网络服务时，通信的安全性和保密性。
+
+### 证书颁发机构和自签名证书
+
+证书颁发机构（CA）是受信任的组织，它可以颁发数字证书。
+
+TLS 和 SSL 可以使连接更安全，但是这个加密机制需要一种方式来验证它；这就是 SSL/TLS 证书。TLS 使用了一种叫做非对称加密的加密机制，这个机制有一对称为私钥和公钥的安全密钥。（这是一个非常复杂的主题，超出了本文的讨论范围，但是如果你想去了解这方面的东西，你可以阅读“[密码学和公钥密码基础体系简介][5]”）你要知道的基础内容是，证书颁发机构们，比如 GlobalSign、DigiCert 和 GoDaddy，它们是受人们信任的可以颁发证书的供应商，它们颁发的证书可以用于验证网站使用的 TLS/SSL 证书。网站使用的证书是导入到主机服务器里的，用于保护网站。
+
+然而，如果你只是要测试一下正在开发中的网站或服务，CA 证书可能对你而言太昂贵或者是太复杂了。你必须有一个用于生产目的的受信任的证书，但是开发者和网站管理员需要有一种更简单的方式来测试网站，然后他们才能将其部署到生产环境中；这就是自签名证书的来源。
+
+自签名证书是一种 TLS/SSL 证书，是由创建它的人而非受信任的 CA 机构颁发的。用电脑生成一个自签名证书很简单，它可以让你在无需购买昂贵的 CA 颁发的证书的情况下测试一个安全网站。虽然自签名证书肯定不能拿到生产环境中去使用，但对于开发和测试阶段来说，这是一种简单灵活的方法。
+
+### 生成证书的开源工具
+
+有几种开源工具可以用来管理 TLS/SSL 证书。其中最著名的就是 openssl，这个工具包含在很多 Linux 发行版中和 MacOS 中。当然，你也可以使用其他开源工具。
+
+| 工具名 | 描述 | 许可证 |
+| --------- | ------------------------------------------------------------------------------ | --------------------------------- |
+| [OpenSSL][7] | 实现 TLS 和加密库的最著名的开源工具 | Apache License 2.0 |
+| [EasyRSA][8] | 用于构建 PKI CA 的命令行实用工具 | GPL v2 |
+| [CFSSL][9] | 来自 cloudflare 的 PKI/TLS 瑞士军刀 | BSD 2-Clause "Simplified" License |
+| [Lemur][10] | 来自网飞的 TLS 创建工具 | Apache License 2.0 |
+
+如果你的目的是扩展和对用户友好，网飞的 Lemur 是一个很有趣的选择。你在[网飞的技术博客][6]上可以查看更多有关它的信息。
+
+### 如何创建一个 Openssl 证书
+
+你可以靠自己来创建证书，下面这个案例就是使用 Openssl 生成一个自签名证书。
+
+1、使用 `openssl` 命令行生成一个私钥：
+
+```
+openssl genrsa -out example.key 2048
+```
+
+
+
+2、使用在第一步中生成的私钥来创建一个证书签名请求（CSR）：
+
+```
+openssl req -new -key example.key -out example.csr -subj "/C=US/ST=TX/L=Dallas/O=Red Hat/OU=IT/CN=test.example.com"
+```
+
+
+
+3、使用你的 CSR 和私钥创建一个证书：
+
+```
+openssl x509 -req -days 366 -in example.csr -signkey example.key -out example.crt
+```
+
+
+
+### 了解更多关于互联网安全的知识
+
+如果你想要了解更多关于互联网安全和网站安全的知识，请看我为这篇文章一起制作的 Youtube 视频。
+
+-
+
+你有什么问题？发在评论里让我们知道。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/11/internet-security-tls-ssl-certificate-authority
+
+作者：[Bryant Son][a]
+选题：[lujun9972][b]
+译者：[hopefully2333](https://github.com/hopefully2333)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/brson
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/security-lock-password.jpg?itok=KJMdkKum
+[2]: https://opensource.com/sites/default/files/uploads/1_certificatecheckwebsite.jpg
+[3]: https://opensource.com/sites/default/files/uploads/2_certificatedisplaywebsite.jpg
+[4]: https://opensource.com/sites/default/files/uploads/3_internetprotocol.jpg
+[5]: https://opensource.com/article/18/5/cryptography-pki
+[6]: https://medium.com/netflix-techblog/introducing-lemur-ceae8830f621
+[7]: https://www.openssl.org/
+[8]: https://github.com/OpenVPN/easy-rsa
+[9]: https://github.com/cloudflare/cfssl
+[10]: https://github.com/Netflix/lemur
diff --git a/published/20191125 The many faces of awk.md b/published/20191125 The many faces of awk.md
new file mode 100644
index 0000000000..53ac02c910
--- /dev/null
+++ b/published/20191125 The many faces of awk.md
@@ -0,0 +1,225 @@
+[#]: collector: (lujun9972)
+[#]: translator: (luuming)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11658-1.html)
+[#]: subject: (The many faces of awk)
+[#]: via: (https://www.networkworld.com/article/3454979/the-many-faces-of-awk.html)
+[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
+
+千面 awk
+======
+
+> `awk` 命令不仅提供了简单的输入字符串筛选功能，还包含提取数据列、打印简单文本、筛选内容——甚至做一些数学计算。
+
+![Thinkstock][6]
+
+如果你仅使用 `awk` 选取一行中的特定文本，那么你可能错过了它的很多功能。在这篇文章中，我们会来看看使用 `awk` 可以帮你做一些其他的什么事情，并提供一些例子。
+
+### 提取数据列
+
+`awk` 所提供的最简单与最常用的功能便是从文件或管道传输的数据中选取特定的内容。默认使用空格当做分隔符，这非常简单。
+
+```
+$ echo one two three four five | awk ‘{print $4}’
+four
+$ who | awk ‘{print $1}’
+jdoe
+fhenry
+```
+
+空格指的是一系列的 `space` 或 `tab` 字符。在下面所展示的命令里，`awk` 从提供的数据中筛选第一和第四项。
+
+`awk` 命令也可以通过在其后增加文件名参数的方式从文本文件中获取数据。
+
+```
+$ awk '{print $1,$5,$NF}' HelenKellerQuote
+The beautiful heart.
+```
+
+（LCTT 译注：“The best and most beautiful things in the world can not be seen or even touched , they must be felt with heart.” ——海伦凯勒）
+
+在这个例子中，`awk` 挑选了一行中的第一个、第五个和最后一个字段。
+
+命令中的 `$NF` 指定选取每行的最后一个字段。这是因为 `NF` 代表一行中的字段数量，也就是 23，而 `$NF` 就代表着那个字段的值，也就是`heart`。最后的句号也包含进去了，因为它是最后一个字符串的一部分。
+
+字段能以任何有用的形式打印。在这个例子中，我们将字段以日期的格式进行打印输出。
+
+```
+$ date | awk '{print $4,$3,$2}'
+2019 Nov 22
+```
+
+如果你省略了 `awk` 命令中字段指示符之间的逗号，输出将会挤成一个字符串。
+
+```
+$ date | awk '{print $4 $3 $2}'
+2019Nov21
+```
+
+如果你将通常使用的逗号替换为连字符，`awk` 就会尝试将两个字段的值相减——或许这并不是你想要的。它不会将连字符插入到输出结果中。相反地，它对输出做了一些数学计算。
+
+```
+$ date | awk '{print $4-$3-$2}'
+1997
+```
+
+在这个例子中，它将年 “2019” 和日期 “22” 相减，并忽略了中间的 “Nov”。
+
+如果你想要空格之外的字符作为输出分隔符，你可以通过 `OFS`（输出分隔符）指定分隔符，就像这样：
+
+```
+$ date | awk '{OFS="-"; print $4,$3,$2}'
+2019-Nov-22
+```
+
+### 打印简单文本
+
+你也可以使用 `awk` 简单地显示一些文本。当然了，比起 `awk` 你可能更想使用 `echo` 命令。但换句话说，作为 `awk` 脚本的一部分，打印某些相关性文本将会非常实用。这里有一个没什么用的例子：
+
+```
+$ awk 'BEGIN {print "Hello, World" }'
+Hello, World
+```
+
+下面的例子更加合理，添加一行文本标签来更好的辨识数据。
+
+```
+$ who | awk 'BEGIN {print "Current logins:"} {print $1}'
+Current logins:
+shs
+nemo
+```
+
+### 指定字段分隔符
+
+不是所有的输入都以空格作为分隔符的。如果你的文本通过其它的字符作为分隔符（例如：逗号、冒号、分号），你可以通过 `-F` 选项（输入分隔符）告诉 `awk`：
+
+```
+$ cat testfile
+a:b:c,d:e
+$ awk -F : '{print $2,$3}' testfile
+b c,d
+```
+
+下面是一个更加有用的例子——从冒号分隔的 `/etc/passwd` 文件中获取数据：
+
+```
+$ awk -F: '{print $1}' /etc/passwd | head -11
+root
+daemon
+bin
+sys
+sync
+games
+man
+lp
+mail
+news
+uucp
+```
+
+### 筛选内容
+
+你也可以使用 `awk` 命令评估字段。例如你仅仅想列出 `/etc/passwd` 中的用户账号，就可以对第三个字段做一些筛选。下面的例子中我们只关注大于等于 1000 的 UID：
+
+```
+$ awk -F":" ' $3 >= 1000 ' /etc/passwd
+nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
+shs:x:1000:1000:Sandra Henry-Stocker,,,:/home/shs:/bin/bash
+nemo:x:1001:1001:Nemo,,,:/home/nemo:/usr/bin/zsh
+dory:x:1002:1002:Dory,,,:/home/dory:/bin/bash
+...
+```
+
+如果你想为输出增加标题，可以添加 `BEGIN` 从句：
+
+```
+$ awk -F":" 'BEGIN {print "user accounts:"} $3 >= 1000 ' /etc/passwd
+user accounts:
+nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
+shs:x:1000:1000:Sandra Henry-Stocker,,,:/home/shs:/bin/bash
+nemo:x:1001:1001:Nemo,,,:/home/nemo:/usr/bin/zsh
+dory:x:1002:1002:Dory,,,:/home/dory:/bin/bash
+```
+
+如果你想要不止一行的标题，你可以通过 `"\n"` 分隔输出：
+
+```
+$ awk -F":" 'BEGIN {print "user accounts\n============="} $3 >= 1000 ' /etc/passwd
+user accounts
+=============
+nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
+shs:x:1000:1000:Sandra Henry-Stocker,,,:/home/shs:/bin/bash
+nemo:x:1001:1001:Nemo,,,:/home/nemo:/usr/bin/zsh
+dory:x:1002:1002:Dory,,,:/home/dory:/bin/bash
+```
+
+### 在 awk 中进行数学计算
+
+`awk` 提供了惊人的数学计算能力，并且可以开平方，算 `log`，算 `tan` 等等。
+
+这里有一对例子：
+
+```
+$ awk 'BEGIN {print sqrt(2019)}'
+44.9333
+$ awk 'BEGIN {print log(2019)}'
+7.61036
+```
+
+想要详细了解 `awk` 的数学计算能力，可以看《[使用 awk 进行数学计算][3]》这篇文章。
+
+### awk 脚本
+
+你也可以使用 `awk` 写一套单独的脚本。下面的例子模仿了之前写过的一个，不过还计算了系统里账户的数量。
+
+```
+#!/usr/bin/awk -f
+
+# 这一行是注释
+
+BEGIN {
+ printf "%s\n","User accounts:"
+ print "=============="
+ FS=":"
+ n=0
+}
+
+# 现在开始遍历数据
+{
+ if ($3 >= 1000) {
+ print $1
+ n ++
+ }
+}
+
+END {
+ print "=============="
+ print n " accounts"
+}
+```
+
+注意 `BEGIN` 那一节是如何提供标题、指定字段分隔符和初始化计数器的，它仅在脚本初始化时期执行。这个脚本也包含 `END` 节，它仅在中间所有命令处理完成之后运行，显示了所有中间小节所筛选数据的最终行数（第三个字段大于等于 1000）。
+
+作为一个长存于 Unix 之上的命令，`awk` 依旧提供着非常有用的服务，这也是我几十年前爱上 Unix 的原因之一。
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3454979/the-many-faces-of-awk.html
+
+作者：[Sandra Henry-Stocker][a]
+选题：[lujun9972][b]
+译者：[LuuMing](https://github.com/LuuMing)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/newsletters/signup.html
+[2]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[3]: https://www.networkworld.com/article/2974753/doing-math-with-awk.html
+[4]: https://www.facebook.com/NetworkWorld/
+[5]: https://www.linkedin.com/company/network-world
+[6]:https://images.techhive.com/images/article/2015/09/thinkstockphotos-512100549-100611755-large.jpg
diff --git a/published/20191127 Create virtual machines with Cockpit in Fedora.md b/published/20191127 Create virtual machines with Cockpit in Fedora.md
new file mode 100644
index 0000000000..c4de8df42f
--- /dev/null
+++ b/published/20191127 Create virtual machines with Cockpit in Fedora.md
@@ -0,0 +1,95 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11716-1.html)
+[#]: subject: (Create virtual machines with Cockpit in Fedora)
+[#]: via: (https://fedoramagazine.org/create-virtual-machines-with-cockpit-in-fedora/)
+[#]: author: (Karlis KavacisPaul W. Frields https://fedoramagazine.org/author/karlisk/https://fedoramagazine.org/author/pfrields/)
+
+在 Fedora 中使用 Cockpit 创建虚拟机
+======
+
+![][1]
+
+本文向你展示如何在 Fedora 31 上使用安装 Cockpit 所需软件来创建和管理虚拟机。Cockpit 是一个[交互式管理界面][2]，可让你在任何受支持的 Web 浏览器上访问和管理系统。随着 [virt-manager 逐渐被废弃][3]，鼓励用户使用 Cockpit 来替换它。
+
+Cockpit 是一个正在活跃开发的项目，它有许多扩展其工作的插件。例如，其中一个是 “Machines”，它与 libvirtd 交互并允许用户创建和管理虚拟机。
+
+### 安装软件
+
+先决所需软件是 `libvirt`、`cockpit` 和 `cockpit-machines`。要将它们安装在 Fedora 31 上，请在终端[使用 sudo][4] 运行以下命令：
+
+```
+$ sudo dnf install libvirt cockpit cockpit-machines
+```
+
+Cockpit 也在 “Headless Management” 软件包组中。该软件组对于仅通过网络访问的基于 Fedora 的服务器很有用。在这里，请使用以下命令进行安装：
+
+```
+$ sudo dnf groupinstall "Headless Management"
+```
+
+### 设置 Cockpit 服务
+
+安装了必要的软件包后，就该启用服务了。`libvirtd` 服务运行虚拟机，而 Cockpit 有一个激活的套接字服务，可让你访问 Web GUI：
+
+```
+$ sudo systemctl enable libvirtd --now
+$ sudo systemctl enable cockpit.socket --now
+```
+
+这应该足以运行虚拟机并通过 Cockpit 对其进行管理。（可选）如果要从网络上的另一台设备访问并管理计算机，那么需要将该服务开放给网络。为此，请在防火墙配置中添加新规则：
+
+```
+$ sudo firewall-cmd --zone=public --add-service=cockpit --permanent
+$ sudo firewall-cmd --reload
+```
+
+要确认服务正在运行并且没有发生任何问题，请检查服务的状态：
+
+```
+$ sudo systemctl status libvirtd
+$ sudo systemctl status cockpit.socket
+```
+
+此时一切都应该正常工作。Cockpit Web GUI 应该可通过 或 访问。或者，在连接到同一网络的任何其他设备上的 Web 浏览器中输入本地网络 IP。（如果未设置 SSL 证书，那么可能需要允许来自浏览器的连接。）
+
+### 创建和安装机器
+
+使用系统的用户名和密码登录界面。你还可以选择是否允许在此会话中将密码用于管理任务。
+
+选择 “Virtual Machines”，然后选择 “Create VM” 来创建一台新的虚拟机。控制台为你提供几个选项：
+
+ * 使用 Cockpit 的内置库下载操作系统
+ * 使用系统上已下载的安装媒体
+ * 指向系统安装树的 URL
+ * 通过 [PXE][5] 协议通过网络引导媒体
+
+输入所有必要的参数。然后选择 “Create” 启动新虚拟机。
+
+此时，将出现一个图形控制台。大多数现代 Web 浏览器都允许你使用键盘和鼠标与 VM 控制台进行交互。现在，你可以完成安装并使用新的 VM，就像[过去通过 virt-manager][6] 一样。
+
+*照片由 [Miguel Teixeira][7] 发布于 [Flickr][8]（CC BY-SA 2.0）*
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/create-virtual-machines-with-cockpit-in-fedora/
+
+作者：[Karlis Kavacis][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/karlisk/
+[b]: https://github.com/lujun9972
+[1]: https://fedoramagazine.org/wp-content/uploads/2019/11/create-vm-cockpit-816x345.jpg
+[2]: https://cockpit-project.org/
+[3]: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/rhel-8_0_0_release#virtualization_4
+[4]: https://fedoramagazine.org/howto-use-sudo/
+[5]: https://en.wikipedia.org/wiki/Preboot_Execution_Environment
+[6]: https://fedoramagazine.org/full-virtualization-system-on-fedora-workstation-30/
+[7]: https://flickr.com/photos/miguelteixeira/
+[8]: https://flickr.com/photos/miguelteixeira/2964851828/
diff --git a/published/20191127 How to write a Python web API with Flask.md b/published/20191127 How to write a Python web API with Flask.md
new file mode 100644
index 0000000000..8e28adebdf
--- /dev/null
+++ b/published/20191127 How to write a Python web API with Flask.md
@@ -0,0 +1,140 @@
+[#]: collector: (lujun9972)
+[#]: translator: (hj24)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11701-1.html)
+[#]: subject: (How to write a Python web API with Flask)
+[#]: via: (https://opensource.com/article/19/11/python-web-api-flask)
+[#]: author: (Rachel Waston https://opensource.com/users/rachelwaston)
+
+如何使用 Flask 编写 Python Web API
+======
+
+> 这是一个快速教程，用来展示如何通过 Flask（目前发展最迅速的 Python 框架之一）来从服务器获取数据。
+
+![spiderweb diagram][1]
+
+[Python][2] 是一个以语法简洁著称的高级的、面向对象的程序语言。它一直都是一个用来构建 RESTful API 的顶级编程语言。
+
+[Flask][3] 是一个高度可定制化的 Python 框架，可以为开发人员提供用户访问数据方式的完全控制。Flask 是一个基于 Werkzeug 的 [WSGI][4] 工具包和 Jinja 2 模板引擎的”微框架“。它是一个被设计来开发 RESTful API 的 web 框架。
+
+Flask 是 Python 发展最迅速的框架之一，很多知名网站如：Netflix、Pinterest 和 LinkedIn 都将 Flask 纳入了它们的开发技术栈。下面是一个简单的示例，展示了 Flask 是如何允许用户通过 HTTP GET 请求来从服务器获取数据的。
+
+### 初始化一个 Flask 应用
+
+首先，创建一个你的 Flask 项目的目录结构。你可以在你系统的任何地方来做这件事。
+
+```
+$ mkdir tutorial
+$ cd tutorial
+$ touch main.py
+$ python3 -m venv env
+$ source env/bin/activate
+(env) $ pip3 install flask-restful
+Collecting flask-restful
+Downloading https://files.pythonhosted.org/packages/17/44/6e49...8da4/Flask_RESTful-0.3.7-py2.py3-none-any.whl
+Collecting Flask>=0.8 (from flask-restful)
+[...]
+```
+
+### 导入 Flask 模块
+
+然后，在你的 `main.py` 代码中导入 `flask` 模块和它的 `flask_restful` 库：
+
+```
+from flask import Flask
+from flask_restful import Resource, Api
+
+app = Flask(__name__)
+api = Api(app)
+
+class Quotes(Resource):
+ def get(self):
+ return {
+ 'William Shakespeare': {
+ 'quote': ['Love all,trust a few,do wrong to none',
+ 'Some are born great, some achieve greatness, and some greatness thrust upon them.']
+ },
+ 'Linus': {
+ 'quote': ['Talk is cheap. Show me the code.']
+ }
+ }
+
+api.add_resource(Quotes, '/')
+
+if __name__ == '__main__':
+ app.run(debug=True)
+```
+
+### 运行 app
+
+Flask 包含一个内建的用于测试的 HTTP 服务器。来测试一下这个你创建的简单的 API：
+
+```
+(env) $ python main.py
+ * Serving Flask app "main" (lazy loading)
+ * Environment: production
+ WARNING: This is a development server. Do not use it in a production deployment.
+ Use a production WSGI server instead.
+ * Debug mode: on
+ * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
+```
+
+启动开发服务器时将启动 Flask 应用程序，该应用程序包含一个名为 `get` 的方法来响应简单的 HTTP GET 请求。你可以通过 `wget`、`curl` 命令或者任意的 web 浏览器来测试它。
+
+```
+$ curl http://localhost:5000
+{
+ "William Shakespeare": {
+ "quote": [
+ "Love all,trust a few,do wrong to none",
+ "Some are born great, some achieve greatness, and some greatness thrust upon them."
+ ]
+ },
+ "Linus": {
+ "quote": [
+ "Talk is cheap. Show me the code."
+ ]
+ }
+}
+```
+
+要查看使用 Python 和 Flask 的类似 Web API 的更复杂版本，请导航至美国国会图书馆的 [Chronicling America][5] 网站，该网站可提供有关这些信息的历史报纸和数字化报纸。
+
+### 为什么使用 Flask?
+
+Flask 有以下几个主要的优点：
+
+ 1. Python 很流行并且广泛被应用，所以任何熟悉 Python 的人都可以使用 Flask 来开发。
+ 2. 它轻巧而简约。
+ 3. 考虑安全性而构建。
+ 4. 出色的文档，其中包含大量清晰，有效的示例代码。
+
+还有一些潜在的缺点:
+
+ 1. 它轻巧而简约。但如果你正在寻找具有大量捆绑库和预制组件的框架，那么这可能不是最佳选择。
+ 2. 如果必须围绕 Flask 构建自己的框架，则你可能会发现维护自定义项的成本可能会抵消使用 Flask 的好处。
+
+
+如果你要构建 Web 程序或 API，可以考虑选择 Flask。它功能强大且健壮，并且其优秀的项目文档使入门变得容易。试用一下，评估一下，看看它是否适合你的项目。
+
+在本课中了解更多信息关于 Python 异常处理以及如何以安全的方式进行操作。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/11/python-web-api-flask
+
+作者：[Rachel Waston][a]
+选题：[lujun9972][b]
+译者：[hj24](https://github.com/hj24)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/rachelwaston
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web-cms-build-howto-tutorial.png?itok=bRbCJt1U (spiderweb diagram)
+[2]: https://www.python.org/
+[3]: https://palletsprojects.com/p/flask/
+[4]: https://en.wikipedia.org/wiki/Web_Server_Gateway_Interface
+[5]: https://chroniclingamerica.loc.gov/about/api
diff --git a/translated/tech/20191129 A quick introduction to Toolbox on Fedora.md b/published/20191129 A quick introduction to Toolbox on Fedora.md
similarity index 67%
rename from translated/tech/20191129 A quick introduction to Toolbox on Fedora.md
rename to published/20191129 A quick introduction to Toolbox on Fedora.md
index 07b7fd64a5..bfcad3cc06 100644
--- a/translated/tech/20191129 A quick introduction to Toolbox on Fedora.md
+++ b/published/20191129 A quick introduction to Toolbox on Fedora.md
@@ -1,26 +1,26 @@
[#]: collector: (lujun9972)
[#]: translator: (geekpi)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11651-1.html)
[#]: subject: (A quick introduction to Toolbox on Fedora)
[#]: via: (https://fedoramagazine.org/a-quick-introduction-to-toolbox-on-fedora/)
[#]: author: (Ryan Walter https://fedoramagazine.org/author/rwaltr/)
-快速介绍 Fedora 中的 Toolbox
+Fedora 中的 Toolbox 简介
======
![][1]
-Toolbox 使你可以[在容器中分类和管理开发环境][2]，而无需 root 权限或手动添加卷。它创建一个容器，你可以在其中安装自己的命令行工具，而无需在基础系统中安装它们。当你没有root 权限或无法直接安装程序时，也可以使用它。本文会介绍 Toolbox 及其功能。
+Toolbox 使你可以[在容器中分类和管理开发环境][2]，而无需 root 权限或手动添加卷。它创建一个容器，你可以在其中安装自己的命令行工具，而无需在基础系统中安装它们。当你没有 root 权限或无法直接安装程序时，也可以使用它。本文会介绍 Toolbox 及其功能。
### 安装 Toolbox
-[Silverblue][3] 默认包含 Toolbox。对于 Workstation 和 Server 版本，你可以使用 _dnf install toolbox_ 从默认仓库中获取它。
+[Silverblue][3] 默认包含 Toolbox。对于 Workstation 和 Server 版本，你可以使用 `dnf install toolbox` 从默认仓库中获取它。
### 创建 Toolbox
-打开终端并运行 _toolbox enter_。程序将自动请求许可来下载最新的镜像，创建第一个容器并将你的 shell 放在该容器中。
+打开终端并运行 `toolbox enter`。程序将自动请求许可来下载最新的镜像，创建第一个容器并将你的 shell 放在该容器中。
```
$ toolbox enter
@@ -29,7 +29,7 @@ Image required to create toolbox container.
Download registry.fedoraproject.org/f30/fedora-toolbox:30 (500MB)? [y/N]: y
```
-当前，toolbox 和你的基本系统之间没有区别。你的文件系统和软件包未更改。这是一个使用仓库的示例，它包含 _~/src/resume_ 文件夹下的简历的文档源。简历是使用 _pandoc_ 工具构建的。
+当前，Toolbox 和你的基本系统之间没有区别。你的文件系统和软件包未曾改变。下面是一个使用仓库的示例，它包含 `~/src/resume` 文件夹下的简历的文档源文件。简历是使用 `pandoc` 工具构建的。
```
$ pwd
@@ -47,7 +47,7 @@ $ pandoc -v
bash: pandoc: command not found
```
-这个 toolbox 没有构建简历所需的程序。你可以通过使用 _dnf_ 安装工具来解决此问题。由于正在容器中运行，因此不会提示你输入 root 密码。
+这个 toolbox 没有构建简历所需的程序。你可以通过使用 `dnf` 安装工具来解决此问题。由于正在容器中运行，因此不会提示你输入 root 密码。
```
$ sudo dnf groupinstall "Authoring and Publishing" -y && sudo dnf install pandoc make -y
@@ -63,7 +63,7 @@ $ ls BUILDS/
resume.docx resume.html resume.pdf resume.rtf resume.txt
```
-运行 _exit_ 退出 toolbox。
+运行 `exit` 可以退出 toolbox。
```
$ cd BUILDS/
@@ -80,21 +80,17 @@ bash: pandoc: command not found...
resume.docx resume.html resume.pdf resume.rtf resume.txt
```
-你会在主目录中得到由 toolbox 创建的文件。toolbox 中安装的程序无法在外部访问。
+你会在主目录中得到由 toolbox 创建的文件。而在 toolbox 中安装的程序无法在外部访问。
### 提示和技巧
-本介绍仅涉及 toolbox 的表明。还有一些其他提示，但是你也可以查看[官方文档][2]。
+本介绍仅涉及 toolbox 的表面。还有一些其他提示，但是你也可以查看[官方文档][2]。
- * _Toolbox –help_ 会显示 Toolbox 的手册页
- * 你可以一次有多个 toolbox。使用 _toolbox create -c Toolboxname_ 和 _toolbox enter -c Toolboxname_。
- * Toolbox 使用 [Podman][4] 来完成繁重的工作。使用 _toolbox list_ 查找 Toolbox 创建的容器的 ID。Podman 可以使用这些 ID 来执行 _rm_ 和 _stop_ 之类的操作。 （你也可以在[此文章][5]中阅读有关 Podman 的更多信息。）
+* `toolbox –help` 会显示 Toolbox 的手册页。
+* 你可以一次有多个 toolbox。使用 `toolbox create -c Toolboxname` 和 `toolbox enter -c Toolboxname`。
+* Toolbox 使用 [Podman][4] 来完成繁重的工作。使用 `toolbox list` 可以查找 Toolbox 创建的容器的 ID。Podman 可以使用这些 ID 来执行 `rm` 和 `stop` 之类的操作。 （你也可以在[此文章][5]中阅读有关 Podman 的更多信息。）
-* * *
-
-_照片出自 [Flickr][7] 的 [Florian Richter][6]。_
-
--------------------------------------------------------------------------------
via: https://fedoramagazine.org/a-quick-introduction-to-toolbox-on-fedora/
@@ -102,7 +98,7 @@ via: https://fedoramagazine.org/a-quick-introduction-to-toolbox-on-fedora/
作者：[Ryan Walter][a]
选题：[lujun9972][b]
译者：[geekpi](https://github.com/geekpi)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/translated/tech/20191202 Use the Window Maker desktop on Linux.md b/published/20191202 Use the Window Maker desktop on Linux.md
similarity index 57%
rename from translated/tech/20191202 Use the Window Maker desktop on Linux.md
rename to published/20191202 Use the Window Maker desktop on Linux.md
index 41082d7fc0..d3225b5a59 100644
--- a/translated/tech/20191202 Use the Window Maker desktop on Linux.md
+++ b/published/20191202 Use the Window Maker desktop on Linux.md
@@ -1,20 +1,21 @@
[#]: collector: (lujun9972)
[#]: translator: (geekpi)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11650-1.html)
[#]: subject: (Use the Window Maker desktop on Linux)
[#]: via: (https://opensource.com/article/19/12/linux-window-maker-desktop)
[#]: author: (Seth Kenlon https://opensource.com/users/seth)
在 Linux 上使用 Window Maker 桌面
======
-本文是 24 天 Linux 桌面特别系列的一部分。与 Window Maker 一起倒退，它为如今的用户实现了老式 Unix NeXTSTEP 环境。
+> 本文是 24 天 Linux 桌面特别系列的一部分。让我们和 Window Maker 一起时光倒流，它为如今的用户实现了老式 Unix NeXTSTEP 环境。
+
![Penguin with green background][1]
-在 Mac OS X 之前，有一个古怪的闭源 Unix 系统，称为 [NeXTSTEP][2]。Sun Microsystems 后来将 NeXTSTEP 的基础设为开放规范，这使其他项目可以创建许多免费开源的 NeXT 库和组件。GNUStep 实现了 NeXTSTEP 的大量库，[Window Maker][3] 实现了其桌面环境。
+在 Mac OS X 之前，有一个奇怪的闭源 Unix 系统，称为 [NeXTSTEP][2]。Sun Microsystems 后来将 NeXTSTEP 的底层设为开放规范，这使其它项目可以创建许多自由开源的 NeXT 库和组件。GNUStep 实现了许多 NeXTSTEP 库，而 [Window Maker][3] 实现了其桌面环境。
-Window Maker 非常接近地模仿了 NeXTSTEP 桌面GUI，并提供了一些有趣东西来了解 80 年代末 90 年代初的 Unix 是什么样子。它还揭示了窗口管理器（例如 Fluxbox 和 Openbox）背后的一些基本概念。
+Window Maker 非常接近地模仿了 NeXTSTEP 桌面 GUI，并提供了一个有趣的视角，可以让人了解 80 年代末 90 年代初的 Unix 是什么样子的。它还揭示了窗口管理器（例如 Fluxbox 和 Openbox）背后的一些基本概念。
你可以从发行版的仓库中安装 Window Maker。要尝试它，请在安装完成后退出桌面会话。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，这取决于你的设置）将继续将登录到默认桌面，因此登录时必须覆盖默认设置。
@@ -26,20 +27,19 @@ Window Maker 非常接近地模仿了 NeXTSTEP 桌面GUI，并提供了一些有
![Selecting the Window Maker desktop in KDM][5]
-### Window Maker dock
+### Window Maker 程序坞
-默认情况下，Window Maker 桌面是空的，但每个角落都有几个 _dock_。像在 NeXTSTEP 中一样，在 Window Maker 中，在 dock 区，应用可最小化成图标后停靠，可创建启动器来快速访问常见应用，并且可运行微型的 ”dockapp“。
-
-你可以在软件仓库中搜索 “dockapp” 来试用 dockapp。它们常常是网络和系统监控器、音频设置面板、时钟等。这是在 Fedora 上运行 Window Maker：
+默认情况下，Window Maker 桌面是空的，但每个角落都有几个*程序坞*。像在 NeXTSTEP 中一样，在 Window Maker 中，在程序坞区域，应用可最小化成图标后停靠，可创建启动器来快速访问常见应用，并且可运行微型的 “dockapp”。
+你可以在软件仓库中搜索 “dockapp” 来试用 dockapp。它们常常是网络和系统监控器、音频设置面板、时钟等。这是在 Fedora 上运行的 Window Maker：
![Window Maker running on Fedora][6]
### 应用菜单
-要访问应用菜单，请右键单击桌面上的任意位置。要再次关闭它，请单击鼠标右键。Window Maker 不是桌面环境。而是一个窗口管理器。它可以帮助你安排和管理窗口。它唯一捆绑的程序是 [WPrefs][7]（或更常见的说法 Window Maker Preferences），它可帮助你配置常用设置，而应用菜单则提供对其他选项（包括主题）的访问。
+要访问应用菜单，请右键单击桌面上的任意位置。要关闭它，请再次单击鼠标右键。Window Maker 不是桌面环境（DE），而是一个窗口管理器（DM）。它可以帮助你安排和管理窗口。它唯一捆绑的程序是 [WPrefs][7]（或更常见的说法 Window Maker 偏好），它可帮助你配置常用设置，而应用菜单则提供对其他选项（包括主题）的访问。
-运行什么应用完全由你决定。在 Window Maker 中，你可以选择运行 KDE 应用、GNOME 应用以及不被视为任何其他不被视为桌面程序的应用。你可以创建自己的工作环境，并且可以使用 Window Maker 对其进行管理。
+运行什么应用完全由你决定。在 Window Maker 中，你可以选择运行 KDE 应用、GNOME 应用以及不被视为任何其他主流桌面应用的程序。你可以创建自己的工作环境，并且可以使用 Window Maker 对其进行管理。
--------------------------------------------------------------------------------
@@ -48,7 +48,7 @@ via: https://opensource.com/article/19/12/linux-window-maker-desktop
作者：[Seth Kenlon][a]
选题：[lujun9972][b]
译者：[geekpi](https://github.com/geekpi)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/translated/tech/20191203 An idiot-s guide to Kubernetes, low-code developers, and other industry trends.md b/published/20191203 An idiot-s guide to Kubernetes, low-code developers, and other industry trends.md
similarity index 69%
rename from translated/tech/20191203 An idiot-s guide to Kubernetes, low-code developers, and other industry trends.md
rename to published/20191203 An idiot-s guide to Kubernetes, low-code developers, and other industry trends.md
index 277378d8f4..6e13e0dbfd 100644
--- a/translated/tech/20191203 An idiot-s guide to Kubernetes, low-code developers, and other industry trends.md
+++ b/published/20191203 An idiot-s guide to Kubernetes, low-code developers, and other industry trends.md
@@ -1,46 +1,55 @@
[#]: collector: (lujun9972)
[#]: translator: (algzjh)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11681-1.html)
[#]: subject: (An idiot's guide to Kubernetes, low-code developers, and other industry trends)
[#]: via: (https://opensource.com/article/19/12/technology-advice-and-other-industry-trends)
[#]: author: (Tim Hildred https://opensource.com/users/thildred)
-面向 Kubernetes，低代码开发人员和其他行业趋势的傻瓜指南
+每周开源点评：Kubernetes 傻瓜指南、低代码开发人员和其他行业趋势
======
-每周查看开源社区，市场和行业趋势。
+> 每周开源社区、市场和行业趋势。
+
![Person standing in front of a giant computer screen with numbers, data][1]
-我在一家采用开源开发模型的企业软件公司担任高级产品营销经理，作为该职位的一部分，我定期为产品营销人员，经理和其他有影响力的人发布有关开源社区，市场和行业趋势的最新信息。这里有该更新中我和他们最喜欢的四篇文章。
+作为我在具有开源开发模型的企业软件公司担任高级产品营销经理的角色的一部分，我为产品营销人员、经理和其他影响者定期发布有关开源社区，市场和行业趋势的定期更新。这里有该更新中我和他们最喜欢的四篇文章。
-## [Kubernetes 的傻瓜指南][2]
+### Kubernetes 傻瓜指南
+
+- [文章链接][2]
> Kubernetes 已经发展出了新的特性，这使其成为企业软件的更好的容器平台。安全性和高级网络等元素已被纳入 Kubernetes 上游代码的主体，并且现在可供所有人使用。
>
> 然而，企业解决方案的其他方面总会有补充需求；比如日志记录和性能监控。这就是像 Istio 等辅助包发挥作用的地方，它带来了额外的功能，但是仍使 Kubernetes 的核心保持了合理的大小和特性集。
-**影响**: 我总是发现，人们很容易把对技术发展的认识视为理所当然。当与你打交道的每个人都处于“最前沿”时，你的观点就会歪曲到这样的程度：你甚至可能会认为对最新的（此处插入首选技术）一无所知的人跟不上潮流，而实际上这并没有开始影响他们做自己需要做的事情的能力。那些人不是白痴；他们是我们的朋友、客户、合作伙伴、合作者和社区。
+**影响**: 我总是发现，人们很容易把对技术发展的认识视为理所当然。当与你打交道的每个人都处于“最前沿”时，你的观点就会歪曲到这样的程度：你甚至可能会认为对最新的（*此处插入首选技术*）一无所知的人跟不上潮流，而实际上这并没有开始影响他们做自己需要做的事情的能力。那些人不是白痴；他们是我们的朋友、客户、合作伙伴、合作者和社区。
-## [Gartner: 采用低代码开发之前应该考虑什么][3]
+### Gartner: 采用低代码开发之前应该考虑什么
-> 尽管专注于业务 IT 团队，但 Gartner(高德纳咨询公司) 发现，一个日益重要的开发人员社区是需要快速开发简单应用程序或构建最低可行产品或多体验功能的核心 IT 专业开发人员。当应用程序领导者在传统的应用程序项目中使用低代码时，他们可能希望使用标准的 IT DevOps 自动化方法和低代码工具。
+- [文章链接][3]
+
+> 尽管专注于商业 IT 团队，但 Gartner 发现，一个日益重要的开发人员社区是需要快速开发简单应用程序或构建最低可行产品或多体验功能的核心 IT 专业开发人员。当应用程序领导者在传统的应用程序项目中使用低代码时，他们可能希望使用标准的 IT DevOps 自动化方法和低代码工具。
**影响**: 越来越多的用例和用户体验可以通过需要更少时间和技能来创建的应用程序来处理和交互。而低代码开发人员也可能会结合成一个具有他们自己的规范和亚文化的独特群体。
-## [诺基亚认为云原生对 5G 核心至关重要][4]
+### 诺基亚认为云原生对 5G 核心至关重要
+
+- [文章链接][4]
> 诺基亚概述了 5G 的五个关键业务目标，这些目标只能通过云原生环境来实现。其中包括：更好的带宽、延迟和密度；通过网络切片将服务扩展到新的企业、行业和[物联网][5]市场；根据敏捷性和效率定义的快速服务部署；超越传统带宽、语音和信息传递的新服务；以及利用端到端网络获取更多收入的数字服务的出现。
**影响**: 在越来越多的事物连接到网络的情况下，这是最有意义的。4G 主要与越来越多的手机有关；只有当你开始连接其他所有东西时，5G 才是真正必要的。4G 意味着我们的手机上有更丰富的应用程序，而 5G 几乎与手机无关。
-## [APIs: 隐藏的业务加速器][6]
+### API：隐藏的业务加速器
-> 要想让组织成功地进行数字化转型，API 策略至关重要。从解锁有价值的数据到加快开发时间，API 都是数字时代谦逊的英雄。那些已经尝试过 API 的人已经感受到了好处。例如，研究表明，使用 API 的企业中，有 53% 认为它们提高了生产力，而 29% 声称它们的收入增长是使用 API 的直接结果。当 API 被视为存在于一个项目之外的可发现和可重用的产品时，它有助于为持续的变更奠定灵活的基础。
+- [文章链接][6]
+
+> 要想让组织成功地进行数字化转型，API 策略至关重要。从解锁有价值的数据到加快开发时间，API 都是数字时代的幕后英雄。那些已经尝试过 API 的人已经感受到了好处。例如，研究表明，使用 API 的企业中，有 53% 认为它们提高了生产力，而 29% 声称它们的收入增长是使用 API 的直接结果。当 API 被视为存在于一个项目之外的可发现和可重用的产品时，它有助于为持续的变更奠定灵活的基础。
**影响**: 隐藏的业务加速器实际上是这样一种思想，即功能应该以一种方式进行打包，使其能够在原始提供者没有预料到的环境中进行重新利用和组合。
-_我希望你喜欢这份上周给我留下深刻印象的列表，并于下周一回来了解更多开源社区、市场和行业的趋势。_
+我希望你喜欢这份上周给我留下深刻印象的列表，并于下周一回来了解更多开源社区、市场和行业的趋势。
--------------------------------------------------------------------------------
@@ -49,7 +58,7 @@ via: https://opensource.com/article/19/12/technology-advice-and-other-industry-t
作者：[Tim Hildred][a]
选题：[lujun9972][b]
译者：[algzjh](https://github.com/algzjh)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/translated/tech/20191203 Using Ansible to organize your SSH keys in AWS.md b/published/20191203 Using Ansible to organize your SSH keys in AWS.md
similarity index 54%
rename from translated/tech/20191203 Using Ansible to organize your SSH keys in AWS.md
rename to published/20191203 Using Ansible to organize your SSH keys in AWS.md
index ffb4e2582a..ff844803c7 100644
--- a/translated/tech/20191203 Using Ansible to organize your SSH keys in AWS.md
+++ b/published/20191203 Using Ansible to organize your SSH keys in AWS.md
@@ -1,34 +1,34 @@
[#]: collector: (lujun9972)
[#]: translator: (hj24)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11653-1.html)
[#]: subject: (Using Ansible to organize your SSH keys in AWS)
[#]: via: (https://fedoramagazine.org/using-ansible-to-organize-your-ssh-keys-in-aws/)
[#]: author: (Daniel Leite de Abreu https://fedoramagazine.org/author/dabreu/)
-在 AWS 中使用 Ansible 来管理你的 SSH keys
+在 AWS 中使用 Ansible 来管理你的 SSH 密钥
======
![][1]
-如果你长期使用亚马逊Web服务（AWS）中的实例，你可能会遇到下面这个常见的问题，它不是因为技术性的原因导致的，更多的是因为人类追求方便舒适的天性：当你登录一台你最近没有使用的区域的实例，你最终就会创建一个新的SSH密钥对，久而久之这最终就会造成个人拥有太多密钥，导致管理起来复杂混乱。
+如果你长期使用亚马逊 Web 服务（AWS）中的实例，你可能会遇到下面这个常见的问题，它不是因为技术性的原因导致的，更多的是因为人类追求方便舒适的天性：当你登录一台你最近没有使用的区域的新实例，你最终会创建一个新的 SSH 密钥对，久而久之这最终就会造成个人拥有太多密钥，导致管理起来复杂混乱。
-本文将会介绍一种在所有区域中使用你的公钥的方法。最近，一篇[Fedora Magazine article][2]介绍了另一种解决方案。但本文中的解决方案可以进一步的以更简洁和可扩展的方式实现自动化。
+本文将会介绍一种在所有区域中使用你的公钥的方法。最近，一篇 [Fedora Magazine 的文章][2]介绍了另一种解决方案。但本文中的解决方案可以进一步的以更简洁和可扩展的方式实现自动化。
-假设你有一个Fedora 30或31系统，其中存储了你的密钥，并且还安装了Ansible。当这两件事同时满足时，就提供了解决这个问题的办法，甚至它还能做到更多。
+假设你有一个 Fedora 30 或 31 系统，其中存储了你的密钥，并且还安装了 Ansible。当这两件事同时满足时，就提供了解决这个问题的办法，甚至它还能做到更多。
-使用Ansible的[ec2_key 模块][3]，你可以创建一个简单的playbook来在所有区域中维护你的SSH密钥对。如果你需要增加或者删除密钥，在ansible中这就像从文件中添加和删除行一样简单。
+使用 Ansible 的 [ec2_key 模块][3]，你可以创建一个简单的 Ansible 剧本来在所有区域中维护你的 SSH 密钥对。如果你需要增加或者删除密钥，在 Ansible 中这就像从文件中添加和删除行一样简单。
-### 设置和运行 playbook
+### 设置和运行 Ansible 剧本
-如果要使用playbook，首先需要安装 _ec2_key_ 模块的必要依赖项：
+如果要使用剧本，首先需要安装 `ec2_key` 模块的必要依赖项：
```
$ sudo dnf install python3-boto python3-boto3
```
-playbook很简单：你只需要像下面的例子一样，修改其中的密钥及其对应的名称。然后，运行playbook，它会帮你遍历所有列出的公共AWS区域。该示例还包括一些受限区域，以防你有访问权限，只需根据需要来取消对应行的注释，然后，保存文件重新运行playbook即可。
+该剧本很简单：你只需要像下面的例子一样，修改其中的密钥及其对应的名称。然后，运行该剧本，它会帮你遍历所有列出的公共 AWS 区域。该示例还包括一些你可能要访问的受限区域，只需根据需要来取消对应行的注释，然后，保存文件重新运行剧本即可。
```
---
@@ -71,34 +71,35 @@ playbook很简单：你只需要像下面的例子一样，修改其中的密钥
# - cn-northwest-1 #China (Ningxia)
```
-这个playbook需要通过API访问AWS，为此，请使用环境变量，如下所示：
+这个剧本需要通过 API 访问 AWS，为此，请使用环境变量，如下所示：
```
$ AWS_ACCESS_KEY="aws-access-key-id" AWS_SECRET_KEY="aws-secret-key-id" ansible-playbook ec2-playbook.yml
```
-另一个选项是安装aws cli工具并添加凭据，如以前的一篇[Fedora Magazine article][4]文章所述。如果你在线存储它们，这些参数将不建议插入到playbook中！你可以在[GitHub][5]中找到本文的playbook代码。
+另一个方式是安装 aws 命令行工具并添加凭据，如以前的一篇 [Fedora Magazine 文章][4]所述。如果你在线存储它们，这些参数将**不建议**插入到剧本中！你可以在 [GitHub][5] 中找到本文的剧本代码。
-完成playbook之后，请确认你的密钥在AWS控制台上可用。为此，可以做如下操作：
- 1. 登录你的AWS控制台
- 2. 转到 **EC2 > Key Pairs**
- 3. 您应该会看到列出的密钥。唯一的限制是你必须使用此方法逐个区域来检查。
+完成该剧本之后，请确认你的密钥在 AWS 控制台上可用。为此，可以做如下操作：
-另一种方法是在shell中使用一个快速命令来为你做这些检查。
+ 1. 登录你的 AWS 控制台
+ 2. 转到 “EC2 > Key Pairs”
+ 3. 你应该会看到列出的密钥。唯一的限制是你必须使用此方法逐个区域来检查。
-首先在playbook上创建一个包含所有区域的变量：
+另一种方法是在 shell 中使用一个快速命令来为你做这些检查。
+
+首先在剧本上创建一个包含所有区域的变量：
```
AWS_REGION="us-east-1 us-west-1 us-west-2 ap-east-1 ap-south-1 ap-northeast-2 ap-southeast-1 ap-southeast-2 ap-northeast-1 ca-central-1 eu-central-1 eu-west-1 eu-west-2 eu-west-3 eu-north-1 me-south-1 sa-east-1"
```
-然后，执行如下循环，你就可以从aws的API获得结果：
+然后，执行如下循环，你就可以从 aws 的 API 获得结果：
```
for each in ${AWS_REGION} ; do aws ec2 describe-key-pairs --key-name ; done
```
-请记住，要执行上述操作，您需要安装 aws cli。
+请记住，要执行上述操作，你需要安装 aws 命令行。
--------------------------------------------------------------------------------
@@ -107,7 +108,7 @@ via: https://fedoramagazine.org/using-ansible-to-organize-your-ssh-keys-in-aws/
作者：[Daniel Leite de Abreu][a]
选题：[lujun9972][b]
译者：[hj24](https://github.com/hj24)
-校对：[校对者ID](https://github.com/校对者ID)
+校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
diff --git a/published/20191203 Why use the Pantheon desktop for Linux Elementary OS.md b/published/20191203 Why use the Pantheon desktop for Linux Elementary OS.md
new file mode 100644
index 0000000000..e54061f81e
--- /dev/null
+++ b/published/20191203 Why use the Pantheon desktop for Linux Elementary OS.md
@@ -0,0 +1,72 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11660-1.html)
+[#]: subject: (Why use the Pantheon desktop for Linux Elementary OS)
+[#]: via: (https://opensource.com/article/19/12/pantheon-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+为何 Elementary OS 中使用 Pantheon 桌面
+======
+
+> 本文是 Linux 桌面特别系列的一部分。通过在 Elementary OS 上运行 Pantheon 桌面获得广受喜爱的 Mac OS 特性。
+
+
+
+你愿意为 Linux 桌面支付 20 美元吗？事实上，我会在下载自由软件时选择支付更多的钱！我这样做的原因是开源是值得的。对于 [Elementary OS][2] 的拷贝，默认价格是 20 美元（你可以选择 1 美元，如果你无法负担，你甚至可以用 0 美元下载）。作为回报，你将获得一个出色且精心制作的发行版，同时拥有它自己的 Pantheon 桌面设计。
+
+你可能会发现 Pantheon 已包含在软件仓库中，因为它是开源的，但你更可能需要下载并安装 [Elementary][3] Linux 才能体验它。如果你还不准备在计算机上将 Elementary 作为主操作系统，那么可以将其安装到虚拟机中，例如 [GNOME Boxes][4] 中。
+
+Pantheon 桌面整洁、吸引人，并且有许多用户希望在桌面中获得的东西，但在普通的 Linux 桌面上却无法获得。
+
+### Pantheon 桌面之旅
+
+乍一看，Pantheon 桌面看起来有点像 Cinnamon、Budgie 或 GNOME 3 的经典模式。但是，Pantheon 最令人兴奋的功能是极小的接触。它在你很少注意到的地方都表现出色，直到有一天这里成为了你一天都会看的地方，并且会意识到它的工作方式确实改善了你的生活质量，更不用说让你过得愉快多了。
+
+最明显的例子是“文件名高亮”。几十年来，Mac OS 一直有一个广受欢迎的功能，你可以高亮显示重要文件的名称。人们使用此功能作为快速视觉指示器，来告诉自己哪个文件是这几个的“最佳”版本，或者哪个文件应该发送给朋友，或者哪个文件仍然需要处理。它们可以是任意颜色，可以表示用户想要的任何含义。最重要的是，它是引人注目的视觉元数据。
+
+从 Mac OS 切换过来用户往往会在 GNOME 和 KDE 以及 Linux 提供的其它桌面里怀念这个功能。Pantheon 悄悄地随手解决了这个问题。
+
+![A highlighted file in the Pantheon desktop][5]
+
+当然，那只是其中一个例子。Pantheon 有很多你直到用才会想到的小功能。
+
+桌面精致而吸引人，有所有其他很多桌面缺少的直观组件。在许多方面，它充分吸取了其他桌面好的想法，并避免实现多余的东西。
+
+![Pantheon desktop on Elementary OS][6]
+
+### 自定义 Pantheon 桌面
+
+Pantheon 桌面表达了如何操作计算机的清晰愿景。这种设计的“问题”（至少在开源之外）是，一个人的偏好可能无法满足另一个人的效率。
+
+但它是开源的。它可以更改，任何不能改变的东西都可以被丢弃。Pantheon 绝对是针对特定用户群的桌面，但是即使对于那些对桌面应该如何工作抱有自己期望的人，Pantheon 也会比初看上去更加灵活。许多内置设计都具有替代选项，当你无法根据自己的喜好进行调整时，你可以轻松选择其他应用。主题引擎可确保你的替换应用看起来与桌面的其它部分和谐一致，而通常的 Linux 系统兼容性可确保你选择的所有应用都能按预期相互配合。
+
+![Which one is the guest?][7]
+
+这些替代品，可使你事半功倍。
+
+### 受欢迎的补充
+
+撇开这个桌面的词源不说，此桌面确实是许多 Linux 用户祈祷的答案（LCTT 译注：Pantheon 的意思是“万神庙”）。无论它是否是你的风格，Pantheon 桌面都是 Linux 用户体验中重要且受欢迎的补充。自己尝试一下，看看它是否是你一直期待的。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/pantheon-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb (A person programming)
+[2]: https://elementary.io/
+[3]: http://elementary.io
+[4]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[5]: https://opensource.com/sites/default/files/uploads/advent-pantheon-highlight.jpg (A highlighted file in the Pantheon desktop)
+[6]: https://opensource.com/sites/default/files/uploads/advent-pantheon.jpg (Pantheon desktop on Elementary OS)
+[7]: https://opensource.com/sites/default/files/uploads/advent-pantheon-pcmanfm.jpg (Which one is the guest?)
diff --git a/published/20191204 Dell XPS 13 7390 Review- The Best Laptop For Desktop Linux Users.md b/published/20191204 Dell XPS 13 7390 Review- The Best Laptop For Desktop Linux Users.md
new file mode 100644
index 0000000000..e97c3a570b
--- /dev/null
+++ b/published/20191204 Dell XPS 13 7390 Review- The Best Laptop For Desktop Linux Users.md
@@ -0,0 +1,67 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11664-1.html)
+[#]: subject: (Dell XPS 13 7390 Review: The Best Laptop For Desktop Linux Users)
+[#]: via: (https://www.linux.com/articles/dell-xps-13-7390-review-the-best-laptop-for-desktop-linux-user/)
+[#]: author: (Swapnil Bhartiya https://www.linux.com/author/swapnil/)
+
+Dell XPS 13 7390：最好的 Linux 桌面笔记本
+======
+
+
+
+曾经，我们必须进行大量研究、阅读大量评论，才能找到一种在所选的 Linux 桌面发行版上可以以最少的麻烦工作的机器。而如今，这种日子已经一去不复返了，几乎每台机器都可以运行 Linux。Linux 内核社区在设备驱动程序支持方面做得非常出色，可以使一切都开箱即用。
+
+不过，有的是**可以**运行 Linux d 机器，有的是运行 Linux 的机器。戴尔计算机属于后一类。五年前，Barton George 在戴尔内部启动了一项计划，将桌面版 Linux 引入到消费级的高端戴尔系统。从一台机器开始，到现在整套从产品线的高端笔记本电脑和台式机都可以运行 Linux。
+
+在这些机器中，XPS 13 是我的最爱。尽管我需要一个功能强大的台式机来处理 4K UHD、多机位视频制作，但我还需要一台超便携的笔记本电脑，可以随身携带，而不必担心笨重的背包和充电器。XPS 13 也是我的第一台笔记本电脑，陪了我 7 年多。因此，是的，这还有一个怀旧因素。
+
+戴尔几乎每年都会更新其 XPS 产品线，并且最新的[产品展示宣布于 10 月][3]。[XPS 13（7390）] [4] 是该系列的增量更新，而且戴尔非常乐意向我寄来一台测评设备。
+
+
+
+它由 6 核 Core i7-10710U CPU 所支持。它配备 16GB 内存和 1TB SSD。在 1.10 GHz 的基本频率（可以超频到 4.1 GHz）的情况下，这是一台用于常规工作负载的出色机器。它没有使用任何专用的 GPU，因此它并不适合进行游戏或从源代码进行编译的 Gentoo Linux 或 Arch Linux。但是，我确实设法在上面运行了一些 Steam 游戏。
+
+如果你想运行 Kubernetes 集群、AI 框架或虚拟现实，那么 Precision 系列中还有更强大的机器，这些机器可以运行 Red Hat Enterprise Linux 和 Ubuntu。
+
+该机器的底盘与上一代相同。边框保持与上一代一样的薄，依旧比 MacBook 和微软的 Surface Pro 薄。
+
+它具有三个端口，其中两个是 USB-C Thunderbolt 3，可用于连接 4K 显示器、USB 附件以及用于对等网络的计算机之间的高速数据传输。
+
+它还具有一个 microSD 插槽。作为视频记者，SD 卡插槽会更有用。大量使用树莓派的用户也会喜欢这种卡。
+
+它具有 4 个麦克风和一个改进的摄像头，该摄像头现在位于顶部（再见，鼻孔摄像头！）。
+
+XPS 13（7390）光滑纤薄。它的重量仅为 2.7 磅（1.2kg），可以与苹果的 MacBook Air 相提并论。 这台机器可以成为你的旅行伴侣，并且可以执行日常任务，例如检查电子邮件、浏览网络和写作。
+
+其 4K UHD 屏幕支持 HDR，这意味着你将可以尽享《The Mandalorian》的全部美妙之处。另外，车载扬声器并没有那么好，听起来有些沉闷。它们适合进行视频聊天或休闲的 YouTube 观看，但是如果你想在今年晚些时候观看《The Witcher》剧集，或者想欣赏 Amazon、Apple Music 或 YouTube Music 的音乐，则需要耳机或外接扬声器。
+
+
+
+但是，在插入充电线之前，你可以能使用这台机器多少时间？在正常工作量的情况下，它为我提供了大约 7-8 个小时的电池续航时间：我打开了几个选项卡浏览网络，只是看看电影或听音乐。多任务处理，尤其是各种 Web 活动，都会加速消耗电池电量。在 Linux 上进行一些微调可能会给你带来更多的续航时间，而在 Windows 10 上，我可以使用 10 多个小时呢！
+
+作为仍在从事大量写作工作的视频记者，我非常喜欢键盘。但是，我们这么多年来在 Linux 台式机上听到的触控板故事一直没变：它与 MacBook 或 Windows 上的品质相差甚远。这或许有一天能改变。值得称道的是，他们确实发布了可增强体验的触控板驱动程序，但我没有运行此系统随附的提供的 Ubuntu 18.04 LTS。我全新安装了 Ubuntu 19.10，因为 Gnome 在 18.04 中的运行速度非常慢。我尝试过 openSUSE Tumbleweed、Zorin OS、elementary OS、Fedora、KDE neon 和 Arch Linux。一切正常，尽管有些需要额外的努力才能运行。
+
+那么，该系统适用于谁？显然，这是给那些想要设计精良的、他们信赖的品牌的高端机器的专业人士打造的。适用于喜欢 MacBook Air，但更喜欢 Linux 台式机生态系统的用户。适用于那些希望使用 Linux 来工作，而不是使 Linux 可以工作的人。
+
+我使用这台机器一周的时间，进一步说明了为什么我如此喜欢戴尔的 XPS 系列。它们是目前最好的 Linux 笔记本电脑。这款 XPS 13（7390），你值得拥有！
+
+--------------------------------------------------------------------------------
+
+via: https://www.linux.com/articles/dell-xps-13-7390-review-the-best-laptop-for-desktop-linux-user/
+
+作者：[Swapnil Bhartiya][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.linux.com/author/swapnil/
+[b]: https://github.com/lujun9972
+[1]: https://www.linux.com/wp-content/uploads/2019/12/dell-xps-13-7390-1068x665.jpg (dell-xps-13-7390)
+[2]: https://www.linux.com/wp-content/uploads/2019/12/dell-xps-13-7390.jpg
+[3]: https://bartongeorge.io/2019/08/21/please-welcome-the-9th-generation-of-the-xps-13-developer-edition/
+[4]: https://blog.dell.com/en-us/dells-new-consumer-pc-portfolio-unveiled-ifa-2019/
diff --git a/published/20191204 Java vs. Python- Which should you choose.md b/published/20191204 Java vs. Python- Which should you choose.md
new file mode 100644
index 0000000000..82e3d842c2
--- /dev/null
+++ b/published/20191204 Java vs. Python- Which should you choose.md
@@ -0,0 +1,130 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11679-1.html)
+[#]: subject: (Java vs. Python: Which should you choose?)
+[#]: via: (https://opensource.com/article/19/12/java-vs-python)
+[#]: author: (Archit Modi https://opensource.com/users/architmodi)
+
+Java 与 Python：你应该选择哪个？
+======
+
+> 比较世界上最流行的两种编程语言，并在投票中让我们知道你喜欢哪一个。
+
+
+
+让我们比较一下世界上两种最受欢迎、最强大的编程语言：Java 和 Python！这两种语言有巨大的社区支持和库来执行几乎任何编程任务，尽管选择编程语言通常取决于开发人员的场景。在比较和对比之后，请投票分享你的观点。
+
+### 是什么？
+
+* **Java** 是一门通用面向对象的编程语言，主要用于开发从移动端到 Web 到企业级应用的各种应用。
+* **Python** 是一门高级面向对象的编程语言，主要用于 Web 开发、人工智能、机器学习、自动化和其他数据科学应用。
+
+### 创建者
+
+* **Java** 是由 James Gosling（Sun Microsystems）创造的。
+* **Python** 是由 Guido van Rossum 创造的。
+
+### 开源状态
+
+* **Java** 是免费的，（大部分）开源，但商业用途除外。
+* **Python** 对于所有场景都是免费、开源的。
+
+### 平台依赖
+
+* **Java** 根据它的 WORA (“一次编写，到处运行”)哲学，它是平台无关的。
+* **Python** 依赖于平台。
+
+### 编译或解释
+
+* **Java** 是一门编译语言。Java 程序在编译时转换为字节码，而不是运行时。
+* **Python** 是一门解释性语言。Python 程序在运行时进行解释。
+
+### 文件创建
+
+* **Java**：编译后生成 `.class` 文件。
+* **Python**：在运行期，创建 `.pyc` 文件。
+
+### 错误类型
+
+* **Java** 有 2 种错误类型：编译和运行时错误。
+* **Python** 有 1 种错误类型：回溯（或运行时）错误。
+
+### 静态或动态类型
+
+* **Java** 是静态类型。当初始化变量时，需要在程序中指定变量的类型，因为类型检查是在编译时完成的。
+* **Python** 是动态类型。变量不需要在初始化时指定类型，因为类型检查是在运行时完成的。
+
+### 语法
+
+* **Java**：每个语句都需要以分号（`;` ）结尾，并且代码块由大括号（ `{}` ）分隔。
+* **Python**：代码块通过缩进分隔（用户可以选择要使用的空格数，但在整个块中应保持一致）。
+
+### 类的数量
+
+* **Java**：在 Java 中的单个文件中只能存在一个公有顶级类。
+* **Python**：Python 中的单个文件中可以存在任意数量的类。
+
+### 代码多少？
+
+* **Java** 通常比 Python 要写更多代码行。
+* **Python**通常比 Java 要写更少代码行。
+
+### 多重继承
+
+* **Java** 不支持多重继承（从两个或多个基类继承）。
+* **Python** 支持多重继承，但由于继承复杂性、层次结构、依赖等各种问题，它很少实现。
+
+### 多线程
+
+* **Java** 多线程可以支持同时运行的两个或多个并发线程。
+* **Python** 使用全局解释器锁 （GIL），一次只允许运行单个线程（一个 CPU 核）。
+
+### 执行速度
+
+* **Java** 的执行时间通常比 Python 快。
+* **Python** 的执行时间通常比 Java 慢。
+
+### Hello world
+
+Java 的：
+
+```
+public class Hello {
+ public static void main([String][3][] args) {
+ [System][4].out.println("Hello Opensource.com from Java!");
+ }
+}
+```
+
+Python 的：
+
+```
+print("Hello Opensource.com from Java!")
+```
+
+### 运行程序
+
+![Java vs. Python][5]
+
+要运行 java 程序 `Hello.java`，你需要先编译它，这将创建一个 `Hello.class` 文件。只需运行类名 `java Hello`。对于 Python，只需运行文件 `python3 helloworld.py`。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/java-vs-python
+
+作者：[Archit Modi][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/architmodi
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_development_programming.png?itok=M_QDcgz5 (Developing code.)
+[2]: tmp.Bpi8QYfp8j#poll
+[3]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+string
+[4]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+system
+[5]: https://opensource.com/sites/default/files/uploads/python-java-hello-world_0.png (Java vs. Python)
diff --git a/published/20191206 5 cool terminal pagers in Fedora.md b/published/20191206 5 cool terminal pagers in Fedora.md
new file mode 100644
index 0000000000..8126cbc54d
--- /dev/null
+++ b/published/20191206 5 cool terminal pagers in Fedora.md
@@ -0,0 +1,103 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11676-1.html)
+[#]: subject: (5 cool terminal pagers in Fedora)
+[#]: via: (https://fedoramagazine.org/5-cool-terminal-pagers-in-fedora/)
+[#]: author: (Jacob Burns https://fedoramagazine.org/author/jaek/)
+
+5 个最酷的终端分页器
+======
+
+![][1]
+
+像日志或源代码这样的大文件可能会多达成千上万行，这使得在文件内导航非常困难，尤其是在终端上。此外，大多数终端仿真器的回滚缓冲区只有几百行。这可能使得无法使用打印到标准输出的实用程序（例如 `cat`、`head` 和 `tail`）在终端中浏览大型文件。在计算时代的早期，程序员通过开发用于以虚拟“页面”形式显示文本的实用程序来解决这些问题，该实用程序被形象地描述为分页器。
+
+*分页器*提供了许多使文本文件导航更加简单的功能，包括滚动、搜索功能，以及作为命令[管道][2]的一部分而具有的功能。与大多数文本编辑器相比，某些终端分页器不需要加载整个文件即可查看，这使得它们更快，特别是对于非常大的文件。
+
+在现代 Linux 计算时代，终端仿真器比以往更加复杂。它们提供了对缤纷的色彩、终端尺寸调整以及许多其它功能的支持，这些功能使得辨析屏幕上的文本变得更加轻松和高效。从诸如 `pg` 和 `more` 这样极其简单的 UNIX 实用程序，到涵盖各种使用场景的、功能广泛的复杂程序，终端分页器也经历了类似的演变。考虑到这一点，我们或“多”或“少”地汇总了一些最受欢迎的终端分页实用程序的列表。
+
+### more
+
+`more` 是最早的分页器之一，最初在 3.0 BSD 版本中出现。`more` 的第一个实现由 [Daniel Halbert][3] 编写于 1978 年。从那时起，`more` 已成为许多操作系统的普遍功能，包括 Windows、OS/2，MacOS 和大多数 Linux 发行版。
+
+`more` 是一个非常轻量级的实用程序。util-linux 软件包中提供的版本只有不到 2100 行的 C 语言代码。但是，这种较小的代码大小是有代价的。大多数版本的 `more` 的功能相对有限，不支持向后滚动或搜索。命令也同样精简：按回车键可滚动一行，或按空格键滚动一页。其他一些有用的命令包括：
+
+* 在阅读时按 `v` 键以在默认的终端编辑器中打开当前文件。
+* `/模式` 可以让你搜索下一个出现的“模式”。
+* 以多个文件作为参数调用 `more` 时，`:n` 和 `:p` 将分别打开下一个和上一个文件
+
+### less
+
+`less` 最初被认为是 `more` 的继承者，解决了它的一些局限性。`less` 以 `more` 的功能为基础，增加了许多有用的功能，包括向后滚动、向后搜索。它也更适合窗口大小调整。
+
+`less` 中的导航方式与 `more` 类似，尽管 `less` 也从 `vi` 编辑器借用了一些有用的命令。用户可以使用熟悉的主行导航键（LCTT 译注：指 左手的 `A`、`S`、`D`、`F` 和右手的 `J`、`K`、`L`、`;`，及大拇指所在的空格键）浏览文档。看一眼 `less` 的手册页，就会发现相当多的可用命令。一些特别有用的示例包括：
+
+* `?模式` 可让你在文件中向后搜索“模式”。
+* `＆模式` 仅显示具有“模式”特征的行。这对于发现自己经常要使用 `$ grep 模式 | less` 的人特别有用。
+* 使用 `-s`（或 `–sqeueeze-blank-lines`）标志来调用 `less`，使你可以查看空白较大的文本文件。 多个换行符被简化为单个中断行。
+* 在该程序中调用的 `s 文件名` 将输入保存到 `文件名`中（如果输入来自管道）。
+* 或者，使用 `-o 文件名` 标志来调用 `less` 将把 `less` 的输入保存到 `文件名` 中。
+
+随着这些增强的功能也带来了体积的略微增大。在写作本文时，Fedora 随附的 `less` 版本大约有 25000 行源代码。当然，除非是受存储限制最大的系统，在所有其它的系统上这都不是问题。`less` 比 `more` 功能更多。
+
+### most
+
+`less` 旨在扩展 `more` 的现有功能，而 `most` 采用另一种方法。`most` 不是在传统的单个文件视图上进行扩展，而是使用户能够将其视图拆分为“窗口”。每个窗口以不同的查看模式包含不同的文件。
+
+重要的是，`most` 考虑了其输入文本的宽度。默认的查看模式是不换行的（`less` 中的 `-S` 参数），此功能在处理“宽”文件时特别有用。尽管对于某些用户来说，这些设计决策可能代表着与传统的重大偏离，但最终结果却非常强大。
+
+除了 `more` 提供的导航命令外，`most` 使用直观的助记符进行文件导航。例如，`t` 移至文件的顶部（Top），而 `b` 移至底部（Bottom）。这样，不熟悉 `vi` 及其衍生品的用户会发现 `most` 非常简单好用。
+
+`most` 的与众不同之处在于它能够快速轻松地拆分窗口和上下文。例如，可以使用以下命令打开两个不同的文本文件：
+
+```
+$ most textFile1.txt textFile2.txt
+```
+
+为了水平拆分屏幕，请使用组合键 `Ctrl+x, 2` 或 `Ctrl+w, 2`。 `:n` 命令将在给定窗口中打开下一个文件参数，提供两个文件的分屏视图：
+
+![][4]
+
+如果在一个窗口中关闭自动换行，它不会影响其他窗口的行为。（行末的）`\` 字符表示换行或折叠，而 `$` 字符表示文件超出了当前窗口的限制。
+
+### pspg
+
+使用 SQL 数据库的人员通常需要能够一目了然地检查数据库的内容。许多流行的开源 DBMS（例如 MySQL 和 PostGreSQL）的命令行界面都使用系统默认的分页器来查看无法显示在单个屏幕上的输出。诸如 `more` 和 `less` 之类的实用程序是围绕呈现文本文件的想法而设计的，但是对于更结构化的数据，还有一些不足之处。天真的文本分页程序没有宽的表格数据的概念，当处理大型查询时，这可能会令人感到沮丧。
+
+[pspg][5] 试图通过为用户提供在查看时冻结列、*原位*排序数据并为输出着色的功能来解决此问题。尽管`pspg` 最初是专门用作 `psql` 的分页器的替代品，但该程序还支持查看 CSV 数据，并且是 `mysql` 和 `pgcli` 的合适的直接替代品。
+
+### Vim
+
+在现代的颜色鲜明的终端中，无休止的黑色页面上的灰色文字感觉太过时了。强大的文本编辑器（如 `vim`）提供的语法高亮显示选项对于浏览源代码很有用。此外，`vim` 提供的搜索功能远远超过了竞争对手。考虑到这一点，`vim` 附带了一个 shell 脚本 `less.sh`，该脚本可以使 `vim` 替代传统的分页器。
+
+要将 `vim` 设置为手册页的[默认分页器][6]，请将以下内容添加到 shell 的配置中（如果使用默认的bash shell 的话是 `~/.bashrc`）：
+
+```
+export MANPAGER="/bin/sh -c \"col -b | vim -c 'set ft=man ts=8 nomod nolist nonu noma' -\""
+```
+
+或者，要将 `vim` 设置为系统范围内的默认分页器，请找到 `less.sh` 脚本。（你可以在当前 Fedora 系统上的 `/usr/share/vim/vim81/macros/` 找到它。）将此位置导出为变量 `PAGER` 以将其设置为默认值，或者将其设置为别名以显式调用它。
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/5-cool-terminal-pagers-in-fedora/
+
+作者：[Jacob Burns][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/jaek/
+[b]: https://github.com/lujun9972
+[1]: https://fedoramagazine.org/wp-content/uploads/2019/11/5-pagers-816x345.jpg
+[2]: https://fedoramagazine.org/command-line-quick-tips-using-pipes-to-connect-tools/
+[3]: https://danhalbert.org/more.html
+[4]: https://fedoramagazine.org/wp-content/uploads/2019/11/image-2.png
+[5]: https://github.com/okbob/pspg
+[6]: https://zameermanji.com/blog/2012/12/30/using-vim-as-manpager/
+[7]: https://unsplash.com/@zyljosa?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
+[8]: https://unsplash.com/s/photos/pages?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
diff --git a/published/20191206 6 Ways to Send Email from the Linux Command Line.md b/published/20191206 6 Ways to Send Email from the Linux Command Line.md
new file mode 100644
index 0000000000..dcfb8ff8ce
--- /dev/null
+++ b/published/20191206 6 Ways to Send Email from the Linux Command Line.md
@@ -0,0 +1,225 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11663-1.html)
+[#]: subject: (6 Ways to Send Email from the Linux Command Line)
+[#]: via: (https://www.2daygeek.com/6-ways-to-send-email-from-the-linux-command-line/)
+[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
+
+Linux 命令行发送邮件的 5 种方法
+======
+
+当你需要在 shell 脚本中创建邮件时，就需要用到命令行发送邮件的知识。Linux 中有很多命令可以实现发送邮件。本教程中包含了最流行的 5 个命令行邮件客户端，你可以选择其中一个。这 5 个命令分别是：
+
+ * `mail` / `mailx`
+ * `mutt`
+ * `mpack`
+ * `sendmail`
+ * `ssmtp`
+
+### 工作原理
+
+我先从整体上来解释下 Linux 中邮件命令怎么把邮件传递给收件人的。邮件命令撰写邮件并发送给一个本地邮件传输代理（MTA，如 sendmail、Postfix）。邮件服务器和远程邮件服务器之间通信以实际发送和接收邮件。下面的流程可以看得更详细。
+
+
+
+### 1) 如何在 Linux 上安装 mail/mailx 命令
+
+`mail` 命令是 Linux 终端发送邮件用的最多的命令。`mailx` 是 `mail` 命令的更新版本，基于 Berkeley Mail 8.1，意在提供 POSIX `mailx` 命令的功能，并支持 MIME、IMAP、POP3、SMTP 和 S/MIME 扩展。mailx 在某些交互特性上更加强大，如缓冲邮件消息、垃圾邮件评分和过滤等。在 Linux 发行版上，`mail` 命令是 `mailx` 命令的软链接。可以运行下面的命令从官方发行版仓库安装 `mail` 命令。
+
+对于 Debian/Ubuntu 系统，使用 [APT-GET 命令][3] 或 [APT 命令][4] 安装 mailutils。
+
+```
+$ sudo apt-get install mailutils
+```
+
+对于 RHEL/CentOS 系统，使用 [YUM 命令][5] 安装 mailx。
+
+```
+$ sudo yum install mailx
+```
+
+对于 Fedora 系统，使用 [DNF 命令][6] 安装 mailx。
+
+```
+$ sudo dnf install mailx
+```
+
+#### 1a) 如何在 Linux 上使用 mail 命令发送邮件
+
+`mail` 命令简单易用。如果你不需要发送附件，使用下面的 `mail` 命令格式就可以发送邮件了：
+
+```
+$ echo "This is the mail body" | mail -s "Subject" 2daygeek@gmail.com
+```
+
+如果你要发送附件，使用下面的 `mail` 命令格式：
+
+```
+$ echo "This is the mail body" | mail -a test1.txt -s "Subject" 2daygeek@gmail.com
+```
+
+- `-a`：用于在基于 Red Hat 的系统上添加附件。
+- `-A`：用于在基于 Debian 的系统上添加附件。
+- `-s`：指定消息标题。
+
+### 2) 如何在 Linux 上安装 mutt 命令
+
+`mutt` 是另一个很受欢迎的在 Linux 终端发送邮件的命令。`mutt` 是一个小而强大的基于文本的程序，用来在 unix 操作系统下阅读和发送电子邮件，并支持彩色终端、MIME、OpenPGP 和按邮件线索排序的模式。可以运行下面的命令从官方发行版仓库安装 `mutt` 命令。
+
+对于 Debian/Ubuntu 系统，使用 [APT-GET 命令][3] 或 [APT 命令][4] 安装 mutt。
+
+```
+$ sudo apt-get install mutt
+```
+
+对于 RHEL/CentOS 系统，使用 [YUM 命令][5] 安装 mutt。
+
+```
+$ sudo yum install mutt
+```
+
+对于 Fedora 系统，使用 [DNF 命令][6] 安装 mutt。
+
+```
+$ sudo dnf install mutt
+```
+
+#### 2b) 如何在 Linux 上使用 mutt 命令发送邮件
+
+`mutt` 一样简单易用。如果你不需要发送附件，使用下面的 `mutt` 命令格式就可以发送邮件了：
+
+```
+$ echo "This is the mail body" | mutt -s "Subject" 2daygeek@gmail.com
+```
+
+如果你要发送附件，使用下面的 `mutt` 命令格式：
+
+```
+$ echo "This is the mail body" | mutt -s "Subject" 2daygeek@gmail.com -a test1.txt
+```
+
+### 3) 如何在 Linux 上安装 mpack 命令
+
+`mpack` 是另一个很受欢迎的在 Linux 终端上发送邮件的命令。`mpack` 程序会在一个或多个 MIME 消息中对命名的文件进行编码。编码后的消息被发送到一个或多个收件人。可以运行下面的命令从官方发行版仓库安装 `mpack` 命令。
+
+对于 Debian/Ubuntu 系统，使用 [APT-GET 命令][3] 或 [APT 命令][4] 安装 mpack。
+
+```
+$ sudo apt-get install mpack
+```
+
+对于 RHEL/CentOS 系统，使用 [YUM 命令][5] 安装 mpack。
+
+```
+$ sudo yum install mpack
+```
+
+对于 Fedora 系统，使用 [DNF 命令][6] 安装 mpack。
+
+```
+$ sudo dnf install mpack
+```
+
+#### 3a) 如何在 Linux 上使用 mpack 命令发送邮件
+
+`mpack` 同样简单易用。如果你不需要发送附件，使用下面的 `mpack` 命令格式就可以发送邮件了：
+
+```
+$ echo "This is the mail body" | mpack -s "Subject" 2daygeek@gmail.com
+```
+
+如果你要发送附件，使用下面的 mpack 命令格式：
+
+```
+$ echo "This is the mail body" | mpack -s "Subject" 2daygeek@gmail.com -a test1.txt
+```
+
+### 4) 如何在 Linux 上安装 sendmail 命令
+
+sendmail 是一个上广泛使用的通用 SMTP 服务器，你也可以从命令行用 `sendmail` 发邮件。可以运行下面的命令从官方发行版仓库安装 `sendmail` 命令。
+
+对于 Debian/Ubuntu 系统，使用 [APT-GET 命令][3] 或 [APT 命令][4]安装 sendmail。
+
+```
+$ sudo apt-get install sendmail
+```
+
+对于 RHEL/CentOS 系统，使用 [YUM 命令][5] 安装 sendmail。
+
+```
+$ sudo yum install sendmail
+```
+
+对于 Fedora 系统，使用 [DNF 命令][6] 安装 sendmail。
+
+```
+$ sudo dnf install sendmail
+```
+
+#### 4a) 如何在 Linux 上使用 sendmail 命令发送邮件
+
+`sendmail` 同样简单易用。使用下面的 `sendmail` 命令发送邮件。
+
+```
+$ echo -e "Subject: Test Mail\nThis is the mail body" > /tmp/send-mail.txt
+```
+
+```
+$ sendmail 2daygeek@gmail.com < send-mail.txt
+```
+
+### 5) 如何在 Linux 上安装 ssmtp 命令
+
+`ssmtp` 是类似 `sendmail` 的一个只发送不接收的工具，可以把邮件从本地计算机传递到配置好的 邮件主机（mailhub）。用户可以在 Linux 命令行用 `ssmtp` 把邮件发送到 SMTP 服务器。可以运行下面的命令从官方发行版仓库安装 `ssmtp` 命令。
+
+对于 Debian/Ubuntu 系统，使用 [APT-GET 命令][3] 或 [APT 命令][4]安装 ssmtp。
+
+```
+$ sudo apt-get install ssmtp
+```
+
+对于 RHEL/CentOS 系统，使用 [YUM 命令][5] 安装 ssmtp。
+
+```
+$ sudo yum install ssmtp
+```
+
+对于 Fedora 系统，使用 [DNF 命令][6] 安装 ssmtp。
+
+```
+$ sudo dnf install ssmtp
+```
+
+### 5a) 如何在 Linux 上使用 ssmtp 命令发送邮件
+
+`ssmtp` 同样简单易用。使用下面的 `ssmtp` 命令格式发送邮件。
+
+```
+$ echo -e "Subject: Test Mail\nThis is the mail body" > /tmp/ssmtp-mail.txt
+```
+
+```
+$ ssmtp 2daygeek@gmail.com < /tmp/ssmtp-mail.txt
+```
+
+--------------------------------------------------------------------------------
+
+via: https://www.2daygeek.com/6-ways-to-send-email-from-the-linux-command-line/
+
+作者：[Magesh Maruthamuthu][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.2daygeek.com/author/magesh/
+[b]: https://github.com/lujun9972
+[1]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
+[2]: https://www.2daygeek.com/wp-content/uploads/2019/12/smtp-simple-mail-transfer-protocol.png
+[3]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/
+[4]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/
+[5]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/
+[6]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/
diff --git a/published/20191206 Pekwm- A lightweight Linux desktop.md b/published/20191206 Pekwm- A lightweight Linux desktop.md
new file mode 100644
index 0000000000..099fe46553
--- /dev/null
+++ b/published/20191206 Pekwm- A lightweight Linux desktop.md
@@ -0,0 +1,93 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11670-1.html)
+[#]: subject: (Pekwm: A lightweight Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/pekwm-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Pekwm：一个轻量级的 Linux 桌面
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。如果你是一个觉得传统桌面会妨碍你的极简主义者，那么试试 Pekwm Linux 桌面。
+
+
+
+假设你想要一个轻量级桌面环境，它只需要能在屏幕上显示图形、四处移动窗口，而别无杂物。你会发现传统桌面的通知、任务栏和系统托盘会妨碍你的工作。你想主要通过终端工作，但也希望运行图形应用。如果听起来像是你的想法，那么 [Pekwm][2] 可能是你一直在寻找的东西。
+
+Pekwm 的灵感大概来自于 Window Maker 和 Fluxbox 等。它提供了一个应用菜单、窗口装饰、而不是一大堆其他东西。它非常适合极简主义者，即那些希望节省资源的用户和喜欢在终端工作的用户。
+
+从发行版仓库安装 Pekwm。安装后，请先退出当前桌面会话，以便可以登录到新桌面。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，具体取决于你的设置）将继续登录到以前的桌面，因此需要在登录之前修改它。
+
+在 GDM 中覆盖之前的桌面：
+
+![Selecting your desktop in GDM][3]
+
+在 KDM 中：
+
+![Selecting your desktop in KDM][4]
+
+第一次登录 Pekwm 时，你可能会看到黑屏。可能难以置信，但这是正常的。你看到的是一个空白桌面，没有背景壁纸。你可以使用 `feh` 命令设置壁纸（你可能需要从仓库中安装它）。此命令有几个用于设置背景的选项，包括 `--bg-fill` 用壁纸填充屏幕，`--bg-scale` 缩放到合适大小，等等。
+
+```
+$ feh --bg-fill ~/Pictures/wallpapers/mybackground.jpg
+```
+
+### 应用菜单
+
+默认情况下，Pekwm 自动生成一个菜单，可在桌面上的任意位置右键单击，从而可让你运行应用。此菜单还提供一些首选项设置，例如选择主题和注销 Pekwm 会话。
+
+![Pekwm running on Fedora][5]
+
+### 配置
+
+Pekwm 主要通过保存在 `$HOME/.pekwm` 下的文本配置文件来配置。`menu` 文件定义你的应用菜单，`keys` 文件定义键盘快捷键，等等。
+
+`start` 文件是在 Pekwm 启动后执行的 shell 脚本。它类似于传统 Unix 系统上的 `rc.local`。它故意放在最后执行的，因此这里的东西将覆盖之前的一切。这是一个重要文件，它可能是你要设置背景的地方，以便*你的*选择会覆盖正在使用的主题的默认值。
+
+`start` 文件也是可以启动 dockapp 的地方。dockapp 是一种小程序，它在 Window Maker 和 Fluxbox 引起了人们的关注。它们通常有网络监视器、时钟、音频设置，和其它你可能会在系统托盘或作为一个 KDE plasmoid 或者完整桌面环境中看到的小部件。你可能会在发行版仓库中找到一些 dockapp，或者可以在 [dockapps.net][6] 上在线查找它们。
+
+你可以在启动时运行 dockapp，将它们列在 `start` 文件中，跟上 `&` 符号：
+
+
+```
+feh --bg-fill ~/Pictures/wallpapers/mybackground.jpg
+wmnd &
+bubblemon -d &
+```
+
+`start` 文件必须[设置为可执行][7]，才能在 Pekwm 启动时运行。
+
+```
+$ chmod +x $HOME/.pekwm/start
+```
+
+### 功能
+
+Pekwm 的功能不多，但这就是它的美。如果你希望在桌面上运行额外的服务，那么由你来启动这些服务。如果你仍在学习 Linux，这是了解那些与完整的桌面环境捆绑在一起时通常不会注意到的微小 GUI 组件的好方法（像是[任务栏][8]）。这也习惯一些 Linux 命令（例如 [nmcli][9]）的好方法。
+
+Pekwm 是一个有趣的窗口管理器。它分散、简洁、轻巧。请试试看！
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/pekwm-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/linux_penguin_green.png?itok=ENdVzW22 (Penguin with green background)
+[2]: http://www.pekwm.org/
+[3]: https://opensource.com/sites/default/files/uploads/advent-gdm_1.jpg (Selecting your desktop in GDM)
+[4]: https://opensource.com/sites/default/files/uploads/advent-enlightenment-kdm_0.jpg (Selecting your desktop in KDM)
+[5]: https://opensource.com/sites/default/files/uploads/advent-pekwm.jpg (Pekwm running on Fedora)
+[6]: http://dockapps.net
+[7]: https://opensource.com/article/19/6/understanding-linux-permissions
+[8]: https://opensource.com/article/19/1/productivity-tool-tint2
+[9]: https://opensource.com/article/19/5/set-static-network-connection-linux
diff --git a/published/20191207 Getting started with the GNOME Linux desktop.md b/published/20191207 Getting started with the GNOME Linux desktop.md
new file mode 100644
index 0000000000..d762dbe15c
--- /dev/null
+++ b/published/20191207 Getting started with the GNOME Linux desktop.md
@@ -0,0 +1,67 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11675-1.html)
+[#]: subject: (Getting started with the GNOME Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/gnome-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+GNOME Linux 桌面入门
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。GNOME 是大多数现代 Linux 发行版的默认桌面，它干净、简单、组织良好。
+
+
+
+[GNOME][2] 项目理所应当是 Linux 桌面的宠儿。它起初是专有桌面（当时包括 KDE）的自由开源的桌面替代品，此后一直发展强劲。GNOME 采用了[由 GIMP 项目开发][3]的 GTK+，并将其开发为强大的通用 GTK 框架。该项目开创了用户界面的先声，挑战了桌面“应有”外观的先入之见，并为用户提供了新的范例和选项。
+
+在大多数主流现代 Linux 发行版（包括 RHEL、Fedora、Debian 和 Ubuntu）中，GNOME 作为默认桌面而广泛使用。如果你的发行版不提供它的某个版本，那么你可以从软件仓库中安装 GNOME。但是，在执行此操作之前，请注意，为了提供完整的桌面体验，这会随桌面一起安装许多 GNOME 应用。如果你在用其他桌面，那么你可能会发现有冗余的应用（两个 PDF 阅读器、两个媒体播放器、两个文件管理器，等等）。如果你只想尝试 GNOME 桌面，请考虑在虚拟机，如 [GNOME Boxes][4]，中安装 GNOME 发行版。
+
+### GNOME 功能
+
+GNOME 桌面很干净，顶部有一个简单的任务栏，右上角的系统托盘中只有很少的图标。GNOME 上没有桌面图标，这是设计使然。如果你是喜欢在桌面上保存*任何东西*的用户，那么你可能会意识到桌面会定期地变得混乱，而且，更糟糕的是，由于你的应用掩盖了桌面，因此桌面永远不会显示出来。
+
+GNOME 解决了两个问题：（在功能上）没有桌面，并且动态生成新的虚拟工作区，因此你可以在全屏模式下运行应用。如果你常把屏幕弄乱，那么可能需要一些时间来习惯，但实际上，从各个方面来说，这都是一种改进的工作流程。你将学习如何使文件井井有条（或者将它们分散在家目录中），并且可以像在手机上一样快速地在屏幕之间切换。
+
+当然，并非所有应用都设计为在全屏模式下运行，因此，如果你更喜欢单击切换窗口，也可以这样做。
+
+![GNOME running on Debian][5]
+
+GNOME 哲学褒扬了 Canonical 对常见任务的解决方案。在 GNOME 中，你通常不会发现“回字有四种写法”。你会找到一种或两种官方方法来完成一项任务，你了解了这些方法后，便只需记住这些即可。它非常简单，但由于它在 Linux 上运行，因此在技术上也很灵活（毕竟，你不必因为运行 GNOME 桌面而必须要使用 GNOME 应用）。
+
+### 应用菜单
+
+要访问名为“活动”的应用菜单，请在桌面的左上角单击。此菜单将占满整个屏幕，屏幕最左侧有一栏常见应用的 dock，或可以在网格中浏览应用的图标。你可以通过浏览已安装的应用，或输入软件的头几个字母来过滤列表，然后来启动应用。
+
+![GNOME activities][6]
+
+### GNOME 应用
+
+GNOME 不仅是桌面。它是一个桌面以及一组丰富的集成应用，例如 Gedit 文本编辑器、Evince PDF 查看器、Web 浏览器、图像查看器、Nautilus 文件管理器等等。GNOME 应用（例如桌面本身）遵循 [GNOME 人机界面指南][7]，因此用户体验既愉悦又一致。无论你是否使用 GNOME 桌面，都可能使用 GTK 应用，也可能会使用 GNOME 应用。
+
+### GNOME 3 及更高版本
+
+GNOME 项目进展顺利，还有几个令人兴奋的项目（例如 MATE 和 [Cinnamon][8]）。它流行、令人舒适，被视为 Linux 桌面的代表。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/gnome-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/custom_gnomes.png?itok=iG98iL8d (Gnomes in a window.)
+[2]: https://www.gnome.org/
+[3]: https://www.gtk.org/overview.php
+[4]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[5]: https://opensource.com/sites/default/files/uploads/advent-gnome.jpg (GNOME running on Debian)
+[6]: https://opensource.com/sites/default/files/uploads/advent-gnome-activities.jpg (GNOME activities)
+[7]: https://developer.gnome.org/hig/stable/
+[8]: https://opensource.com/article/19/11/advent-2019-cinnamon
diff --git a/published/20191209 Counting down the days using bash.md b/published/20191209 Counting down the days using bash.md
new file mode 100644
index 0000000000..d68dc742b6
--- /dev/null
+++ b/published/20191209 Counting down the days using bash.md
@@ -0,0 +1,125 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11672-1.html)
+[#]: subject: (Counting down the days using bash)
+[#]: via: (https://www.networkworld.com/article/3487712/counting-down-the-days-using-bash.html)
+[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
+
+用 bash 倒计时日期
+======
+
+> 需要知道重要事件发生前有多少天吗？让 Linux bash 和 date 命令可以帮助你！
+
+
+
+随着即将来临的重要假期，你可能需要提醒你还要准备多久。
+
+幸运的是，你可以从 `date` 命令获得很多帮助。在本篇中，我们将研究 `date` 和 bash 脚本如何告诉你从今天到你预期的事件之间有多少天。
+
+首先，在进行之前有几个提示。`date` 命令的 `%j` 选项将以 1 至 366 之间的数字显示当前日期。如你所想的一样，1 月 1 日将显示为 1，12 月 31 日将显示为 365 或 366，这取决于是否是闰年。继续尝试。你应该会看到以下内容：
+
+```
+$ date +%j
+339
+```
+
+但是，你可以通过以下方式，在 `date` 命令中得到一年中*任何*一天的数字：
+
+```
+$ date -d "Mar 18" +%j
+077
+```
+
+要记住的是，即使该日期是过去的日期，上面命令也会向你显示*当年*的日期。但是，你可以在命令中添加年来修复该问题：
+
+```
+$ date -d "Apr 29" +%j
+119
+$ date -d "Apr 29 2020" +%j
+120
+```
+
+在闰年中，4 月 29 日将是一年的 120 天，而不是 119 天。
+
+如果你想倒数圣诞节之前的日子并且不想在挂历上留下指纹，你可以使用以下脚本：
+
+```
+#!/bin/sh
+
+XMAS=`date -d "Dec 25" +%j`
+TODAY=`date +%j`
+DAYS=$(($XMAS - $TODAY))
+
+case $DAYS in
+ 0) echo "It's today! Merry Christmas!";;
+ [0-9]*) echo "$DAYS days remaining";;
+ -[0-9]*) echo "Oops, you missed it";;
+esac
+```
+
+在此脚本中，我们获取 12 月 25 日和今天的日期，然后相减。如果结果是正数，我们将显示剩余天数。如果为零，则发出 “Merry Christmas” 的消息，如果为负，那么仅告诉运行脚本的人他们错过了假期。也许他们沉迷在蛋酒中了。
+
+`case` 语句由用来打印信息的语句组成，当剩余时间等于 0，或任意数字或以 `-` 符号开头的数字（也就是过去）分别打印不同的信息。
+
+对于人们想要关注的任何日期，都可以使用相同方法。实际上，我们可以要求运行脚本的人员提供日期，然后让他们知道从现在到那天还有多少天。这个脚本是这样的。
+
+```
+#!/bin/sh
+
+echo -n "Enter event date (e.g., June 6): "
+read dt
+EVENT=`date -d "$dt" +%j`
+TODAY=`date +%j`
+DAYS=`expr $EVENT - $TODAY`
+
+case $DAYS in
+ 0) echo "It's today!";;
+ [0-9]*) echo "$DAYS days remaining";;
+ -[0-9]*) echo "Oops, you missed it";;
+esac
+```
+
+使用此脚本会遇到的一个问题，如果运行该脚本的人希望知道到第二年这个特殊日子还有多少天，他们会感到失望。即使他们输入日期时提供了年，`date -d` 命令仍将仅提供今年中的天数，而不会提供从现在到那时的天数。
+
+计算从今天到某年的日期之间的天数可能有些棘手。你需要包括所有中间年份，并注意那些闰年。
+
+### 使用 Unix 纪元时间
+
+计算从现在到某个特殊日期之间的天数的另一种方法是利用 Unix 系统存储日期的方法。如果将自 1970 年 1 月 1 日开始的秒数转换为天数，那么就可以很容易地执行此操作，如下脚本所示：
+
+```
+#!/bin/bash
+
+echo -n "Enter target date (e.g., Mar 18 2021)> "
+read target_date
+today=`echo $(($(date --utc --date "$1" +%s)/86400))`
+target=`echo $(($(date --utc --date "$target_date" +%s)/86400))`
+days=`expr $target - $today`
+echo "$days days until $target_date"
+```
+
+解释一下，86400 是一天中的秒数。将自 Unix 纪元开始以来的秒数除该数即为天数。
+
+```
+$ ./countdown
+Enter target date (e.g., Mar 18 2021)> Mar 18 2020
+104 days until Mar 18 2020
+```
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3487712/counting-down-the-days-using-bash.html
+
+作者：[Sandra Henry-Stocker][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
+[b]: https://github.com/lujun9972
+[3]: https://www.facebook.com/NetworkWorld/
+[4]: https://www.linkedin.com/company/network-world
diff --git a/published/20191210 3 easy steps to update your apps to Python 3.md b/published/20191210 3 easy steps to update your apps to Python 3.md
new file mode 100644
index 0000000000..19ff8e16db
--- /dev/null
+++ b/published/20191210 3 easy steps to update your apps to Python 3.md
@@ -0,0 +1,158 @@
+[#]: collector: (lujun9972)
+[#]: translator: (HankChow)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11696-1.html)
+[#]: subject: (3 easy steps to update your apps to Python 3)
+[#]: via: (https://opensource.com/article/19/12/update-apps-python-3)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+将你的应用迁移到 Python 3 的三个步骤
+======
+
+> Python 2 气数将尽，是时候将你的项目从 Python 2 迁移到 Python 3 了。
+
+
+
+Python 2.x 很快就要[失去官方支持][2]了，尽管如此，从 Python 2 迁移到 Python 3 却并没有想象中那么难。我在上周用了一个晚上的时间将一个 3D 渲染器的前端代码及其对应的 [PySide][3] 迁移到 Python 3，回想起来，尽管在迁移过程中无可避免地会遇到一些牵一发而动全身的修改，但整个过程相比起痛苦的重构来说简直是出奇地简单。
+
+每个人都别无选择地有各种必须迁移的原因：或许是觉得已经拖延太久了，或许是依赖了某个在 Python 2 下不再维护的模块。但如果你仅仅是想通过做一些事情来对开源做贡献，那么把一个 Python 2 应用迁移到 Python 3 就是一个简单而又有意义的做法。
+
+无论你从 Python 2 迁移到 Python 3 的原因是什么，这都是一项重要的任务。按照以下三个步骤，可以让你把任务完成得更加清晰。
+
+### 1、使用 2to3
+
+从几年前开始，Python 在你或许还不知道的情况下就已经自带了一个名叫 [2to3][4] 的脚本，它可以帮助你实现大部分代码从 Python 2 到 Python 3 的自动转换。
+
+下面是一段使用 Python 2.6 编写的代码：
+
+```
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+mystring = u'abcdé'
+print ord(mystring[-1])
+```
+
+对其执行 2to3 脚本：
+
+
+```
+$ 2to3 example.py
+RefactoringTool: Refactored example.py
+--- example.py (original)
++++ example.py (refactored)
+@@ -1,5 +1,5 @@
+ #!/usr/bin/env python
+ # -*- coding: utf-8 -*-
+
+-mystring = u'abcdé'
+-print ord(mystring[-1])
++mystring = 'abcdé'
++print(ord(mystring[-1]))
+RefactoringTool: Files that need to be modified:
+RefactoringTool: example.py
+```
+
+在默认情况下，`2to3` 只会对迁移到 Python 3 时必须作出修改的代码进行标示，在输出结果中显示的 Python 3 代码是直接可用的，但你可以在 2to3 加上 `-w` 或者 `--write` 参数，这样它就可以直接按照给出的方案修改你的 Python 2 代码文件了。
+
+```
+$ 2to3 -w example.py
+[...]
+RefactoringTool: Files that were modified:
+RefactoringTool: example.py
+```
+
+`2to3` 脚本不仅仅对单个文件有效，你还可以把它用于一个目录下的所有 Python 文件，同时它也会递归地对所有子目录下的 Python 文件都生效。
+
+### 2、使用 Pylint 或 Pyflakes
+
+有一些不良的代码在 Python 2 下运行是没有异常的，在 Python 3 下运行则会或多或少报出错误，这种情况并不鲜见。因为这些不良代码无法通过语法转换来修复，所以 `2to3` 对它们没有效果，但一旦使用 Python 3 来运行就会产生报错。
+
+要找出这种问题，你需要使用 [Pylint][5]、[Pyflakes][6]（或 [flake8][7] 封装器）这类工具。其中我更喜欢 Pyflakes，它会忽略代码风格上的差异，在这一点上它和 Pylint 不同。尽管代码优美是 Python 的一大特点，但在代码迁移的层面上，“让代码功能保持一致”无疑比“让代码风格保持一致”重要得多。
+
+以下是 Pyflakes 的输出样例：
+
+```
+$ pyflakes example/maths
+example/maths/enum.py:19: undefined name 'cmp'
+example/maths/enum.py:105: local variable 'e' is assigned to but never used
+example/maths/enum.py:109: undefined name 'basestring'
+example/maths/enum.py:208: undefined name 'EnumValueCompareError'
+example/maths/enum.py:208: local variable 'e' is assigned to but never used
+```
+
+上面这些由 Pyflakes 输出的内容清晰地给出了代码中需要修改的问题。相比之下，Pylint 会输出多达 143 行的内容，而且多数是诸如代码缩进这样无关紧要的问题。
+
+值得注意的是第 19 行这个容易产生误导的错误。从输出来看你可能会以为 `cmp` 是一个在使用前未定义的变量，实际上 `cmp` 是 Python 2 的一个内置函数，而它在 Python 3 中被移除了。而且这段代码被放在了 `try` 语句块中，除非认真检查这段代码的输出值，否则这个问题很容易被忽略掉。
+
+```
+ try:
+ result = cmp(self.index, other.index)
+ except:
+ result = 42
+
+ return result
+```
+
+在代码迁移过程中，你会发现很多原本在 Python 2 中能正常运行的函数都发生了变化，甚至直接在 Python 3 中被移除了。例如 PySide 的绑定方式发生了变化、`importlib` 取代了 `imp` 等等。这样的问题只能见到一个解决一个，而涉及到的功能需要重构还是直接放弃，则需要你自己权衡。但目前来说，大多数问题都是已知的，并且有[完善的文档记录][8]。所以难的不是修复问题，而是找到问题，从这个角度来说，使用 Pyflake 是很有必要的。
+
+### 3、修复被破坏的 Python 2 代码
+
+尽管 `2to3` 脚本能够帮助你把代码修改成兼容 Python 3 的形式，但对于一个完整的代码库，它就显得有点无能为力了，因为一些老旧的代码在 Python 3 中可能需要不同的结构来表示。在这样的情况下，只能人工进行修改。
+
+例如以下代码在 Python 2.6 中可以正常运行：
+
+```
+class CLOCK_SPEED:
+ TICKS_PER_SECOND = 16
+ TICK_RATES = [int(i * TICKS_PER_SECOND)
+ for i in (0.5, 1, 2, 3, 4, 6, 8, 11, 20)]
+
+class FPS:
+ STATS_UPDATE_FREQUENCY = CLOCK_SPEED.TICKS_PER_SECOND
+```
+
+类似 `2to3` 和 Pyflakes 这些自动化工具并不能发现其中的问题，但如果上述代码使用 Python 3 来运行，解释器会认为 `CLOCK_SPEED.TICKS_PER_SECOND` 是未被明确定义的。因此就需要把代码改成面向对象的结构：
+
+```
+class CLOCK_SPEED:
+ def TICKS_PER_SECOND():
+ TICKS_PER_SECOND = 16
+ TICK_RATES = [int(i * TICKS_PER_SECOND)
+ for i in (0.5, 1, 2, 3, 4, 6, 8, 11, 20)]
+ return TICKS_PER_SECOND
+
+class FPS:
+ STATS_UPDATE_FREQUENCY = CLOCK_SPEED.TICKS_PER_SECOND()
+```
+
+你也许会认为如果把 `TICKS_PER_SECOND()` 改写为一个构造函数（用 `__init__` 函数设置默认值）能让代码看起来更加简洁，但这样就需要把这个方法的调用形式从 `CLOCK_SPEED.TICKS_PER_SECOND()` 改为 `CLOCK_SPEED()` 了，这样的改动或多或少会对整个库造成一些未知的影响。如果你对整个代码库的结构烂熟于心，那么你确实可以随心所欲地作出这样的修改。但我通常认为，只要我做出了修改，都可能会影响到其它代码中的至少三处地方，因此我更倾向于不使代码的结构发生改变。
+
+### 坚持信念
+
+如果你正在尝试将一个大项目从 Python 2 迁移到 Python 3，也许你会觉得这是一个漫长的过程。你可能会费尽心思也找不到一条有用的报错信息，这种情况下甚至会有将代码推倒重建的冲动。但从另一个角度想，代码原本在 Python 2 中就可以运行，要让它能在 Python 3 中继续运行，你需要做的只是对它稍加转换而已。
+
+但只要你完成了迁移，你就得到了这个模块或者整个应用程序的 Python 3 版本，外加 Python 官方的长期支持。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/update-apps-python-3
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[HankChow](https://github.com/HankChow)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/python-programming-code-keyboard.png?itok=fxiSpmnd "Hands on a keyboard with a Python book "
+[2]: https://linux.cn/article-11629-1.html
+[3]: https://pypi.org/project/PySide/
+[4]: https://docs.python.org/3.1/library/2to3.html
+[5]: https://opensource.com/article/19/10/python-pylint-introduction
+[6]: https://pypi.org/project/pyflakes/
+[7]: https://opensource.com/article/19/5/python-flake8
+[8]: https://docs.python.org/3.0/whatsnew/3.0.html
+
diff --git a/published/20191210 Breaking Linux files into pieces with the split command.md b/published/20191210 Breaking Linux files into pieces with the split command.md
new file mode 100644
index 0000000000..0151b678df
--- /dev/null
+++ b/published/20191210 Breaking Linux files into pieces with the split command.md
@@ -0,0 +1,108 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11682-1.html)
+[#]: subject: (Breaking Linux files into pieces with the split command)
+[#]: via: (https://www.networkworld.com/article/3489256/breaking-linux-files-into-pieces-with-the-split-command.html)
+[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
+
+使用 split 命令分割 Linux 文件
+======
+
+> 一些简单的 Linux 命令能让你根据需要分割以及重新组合文件，来适应存储或电子邮件附件大小的限制。
+
+![Marco Verch][1]
+
+Linux 系统提供了一个非常易于使用的命令来分割文件。在将文件上传到限制大小的存储网站或者作为邮件附件之前，你可能需要执行此操作。要将文件分割为多个文件块，只需使用 `split` 命令。
+
+```
+$ split bigfile
+```
+
+默认情况下，`split` 命令使用非常简单的命名方案。文件块将被命名为 `xaa`、`xab`、`xac` 等，并且，大概地，如果你将足够大的文件分割，你甚至可能会得到名为 `xza` 和 `xzz` 的块。
+
+除非你要求，否则该命令将无任何反馈地运行。但是，如果你想在创建文件块时看到反馈，可以使用 `--verbose` 选项。
+
+```
+$ split –-verbose bigfile
+creating file 'xaa'
+creating file 'xab'
+creating file 'xac'
+```
+
+你还可以给文件命名前缀。例如，要将你原始文件分割并命名为 `bigfile.aa`、`bigfile.ab` 等，你可以将前缀添加到 `split` 命令的末尾，如下所示：
+
+```
+$ split –-verbose bigfile bigfile.
+creating file 'bigfile.aa'
+creating file 'bigfile.ab'
+creating file 'bigfile.ac'
+```
+
+请注意，上述命令中显示的前缀的末尾会添加一个点。否则，文件将是 `bigfileaa` 之类的名称，而不是 `bigfile.aa`。
+
+请注意，`split` 命令*不会*删除你的原始文件，只是创建了文件块。如果要指定文件块的大小，可以使用 `-b` 选项将其添加到命令中。例如：
+
+```
+$ split -b100M bigfile
+```
+
+文件大小可以是 KB、MB，GB，最大可以是 YB！只需使 K、M、G、T、P、E、Z 和 Y 这些合适的字母。
+
+如果要基于每个块中的行数而不是字节数来拆分文件，那么可以使用 `-l`（行）选项。在此示例中，每个文件将有 1000 行，当然，最后一个文件可能有较少的行。
+
+```
+$ split --verbose -l1000 logfile log.
+creating file 'log.aa'
+creating file 'log.ab'
+creating file 'log.ac'
+creating file 'log.ad'
+creating file 'log.ae'
+creating file 'log.af'
+creating file 'log.ag'
+creating file 'log.ah'
+creating file 'log.ai'
+creating file 'log.aj'
+```
+
+如果你需要在远程站点上重新组合文件，那么可以使用如下所示的 `cat` 命令轻松地完成此操作：
+
+```
+$ cat x?? > original.file
+$ cat log.?? > original.file
+```
+
+上面所示的分割和组合命令适合于二进制和文本文件。在此示例中，我们将 zip 二进制文件分割为 50KB 的块，之后使用 `cat` 重新组合了它们，然后比较了组合后的文件和原始文件。`diff` 命令验证文件是否相同。
+
+```
+$ split --verbose -b50K zip zip.
+creating file 'zip.aa'
+creating file 'zip.ab'
+creating file 'zip.ac'
+creating file 'zip.ad'
+creating file 'zip.ae'
+$ cat zip.a? > zip.new
+$ diff zip zip.new
+$ <== 无输出 = 无差别
+```
+
+我唯一要提醒的一点的是，如果你经常使用 `split` 并使用默认命名，那么某些文件块可能会覆盖其他的文件块，甚至会比你预期的更多，因为有些是更早之前分割的。
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489256/breaking-linux-files-into-pieces-with-the-split-command.html
+
+作者：[Sandra Henry-Stocker][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
+[b]: https://github.com/lujun9972
+[1]: https://images.idgesg.net/images/article/2018/08/chocolate-chunks-100767935-large.jpg
+[2]: https://creativecommons.org/licenses/by/2.0/legalcode
+[5]: https://www.facebook.com/NetworkWorld/
+[6]: https://www.linkedin.com/company/network-world
diff --git a/published/20191210 Customize your Linux desktop with FVWM.md b/published/20191210 Customize your Linux desktop with FVWM.md
new file mode 100644
index 0000000000..d53602de31
--- /dev/null
+++ b/published/20191210 Customize your Linux desktop with FVWM.md
@@ -0,0 +1,77 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11712-1.html)
+[#]: subject: (Customize your Linux desktop with FVWM)
+[#]: via: (https://opensource.com/article/19/12/fvwm-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+使用 FVWM 自定义 Linux 桌面
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。如果你正在寻找轻巧、快速且简单的 Linux 窗口管理器，那么 FVWM 可以胜任。但是，如果你正在寻找可以深入、探索和魔改的窗口管理器，那么 FVWM 是必须的。
+
+
+
+[FVWM][2] 窗口管理器最早脱胎于对 1993 年的 [TWM][3] 的修改。经过几年的迭代，诞生了一个可高度自定义的环境，它可以配置任何行为、动作或事件。它支持自定义键绑定、鼠标手势、主题、脚本等。
+
+尽管 FVWM 在安装后即可投入使用，但默认分发版本仅提供了极其少的配置。这是开始自定义桌面环境的良好基础，但是，如果你只想将其用作桌面，那么可能要安装由其它用户发布的完整配置版本。FVWM 有几种不同的分发版，包括模仿 Windows 95 的 FVWM95（至少在外观和布局上）。我尝试了 [FVWM-Crystal][4]，这是一个具有一些现代 Linux 桌面约定的现代主题。
+
+可以从 Linux 发行版的软件仓库中安装要尝试的 FVWM 分发版。如果找不到特定的 FVWM 分发版，那么可以安装基础的 FVWM2 包，然后进入 [Box-Look.org][5] 手动下载主题包。这样就需要更多的工作，但比从头开始构建要少。
+
+安装后，请注销当前的桌面会话，以便你可以登录 FVWM。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，取决于你的设置）将继续登录到以前的桌面，因此你必须在登录之前覆盖该桌面。
+
+对于 GDM：
+
+![Select your desktop session in GDM][6]
+
+对于 KDM：
+
+![Select your desktop session with KDM][7]
+
+### FVWM 桌面
+
+无论你使用什么主题和配置，当你在桌面上单击鼠标左键时，FVWM 至少会显示一个菜单。菜单的内容取决于你所安装的内容。FVWM-Crystal 分发版中的菜单包含对常用首选项的快速访问，例如屏幕分辨率、壁纸设置、窗口装饰等。
+
+同 FVWM 中的几乎所有东西一样，你可以编辑菜单中你要想的内容，但 FVWM-Crystal 的特色在于其应用菜单栏。应用菜单位于屏幕的左上角，每个图标都包含了相关的应用启动器的菜单。例如，GIMP 图标表示图像编辑器，KDevelop 图标表示集成开发环境（IDE），GNU 图标表示文本编辑器，等等，具体取决于你在系统上安装的程序。
+
+![FVWM-crystal running on Slackware 14.2][8]
+
+FVWM-Crystal 还提供了虚拟桌面、任务栏、时钟和应用栏。
+
+关于背景，你可以使用与 FVWM-Crystal 捆绑在一起的壁纸，也可以使用 `feh` 命令设置自己的壁纸（你可能需要从仓库中安装它）。此命令有一些设置背景的选项，包括 `--bg-scale` 使用你选择的图片缩放填充屏幕，`--bg-fill` 直接填充而不缩放图片，等等。
+
+```
+$ feh --bg-scale ~/Pictures/wallpapers/mybackground.jpg
+```
+
+大多数配置文件都包含在 `$HOME/.fvwm-crystal` 中，某些系统范围的默认文件位于 `/usr/share/fvwm-crystal`。
+
+### 自己尝试一下
+
+FVWM 是大多作为一个桌面构建平台，它也是窗口管理器。它不会为你做到面面俱到，它期望你来配置尽可能的一切。
+
+如果你正在寻找轻巧、快速且简单的窗口管理器，那么 FVWM 可以胜任。但是，如果你正在寻找可以深入、探索和魔改的窗口管理器，那么 FVWM 是必须的。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/fvwm-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_laptop_hack_work.png?itok=aSpcWkcl (Coding on a computer)
+[2]: http://www.fvwm.org/
+[3]: https://en.wikipedia.org/wiki/Twm
+[4]: https://www.box-look.org/p/1018270/
+[5]: http://box-look.org
+[6]: https://opensource.com/sites/default/files/advent-gdm_0.jpg (Select your desktop session in GDM)
+[7]: https://opensource.com/sites/default/files/advent-kdm.jpg (Select your desktop session with KDM)
+[8]: https://opensource.com/sites/default/files/advent-fvwm-crystal.jpg (FVWM-crystal running on Slackware 14.2)
diff --git a/published/20191211 Annotate screenshots on Linux with Ksnip.md b/published/20191211 Annotate screenshots on Linux with Ksnip.md
new file mode 100644
index 0000000000..2e940a50cd
--- /dev/null
+++ b/published/20191211 Annotate screenshots on Linux with Ksnip.md
@@ -0,0 +1,100 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11695-1.html)
+[#]: subject: (Annotate screenshots on Linux with Ksnip)
+[#]: via: (https://opensource.com/article/19/12/annotate-screenshots-linux-ksnip)
+[#]: author: (Clayton Dewey https://opensource.com/users/cedewey)
+
+在 Linux 上使用 Ksnip 注释截图
+======
+
+> Ksnip 让你能轻松地在 Linux 中创建和标记截图。
+
+![a checklist for a team][1]
+
+我最近从 MacOS 切换到了 [Elementary OS][2]，这是一个专注于易用性和隐私性的 Linux 发行版。作为用户体验设计师和自由软件支持者，我会经常截图并进行注释。在尝试了几种不同的工具之后，到目前为止，我最喜欢的工具是 [Ksnip][3]，它是 GPLv2 许可下的一种开源工具。
+
+![Ksnip screenshot][4]
+
+### 安装
+
+使用你首选的包管理器安装 Ksnip。我通过 Apt 安装了它：
+
+```
+sudo apt-get install ksnip
+```
+
+### 配置
+
+Ksnip 有许多配置选项，包括：
+
+* 保存截图的地方
+* 默认截图的文件名
+* 图像采集器行为
+* 光标颜色和宽度
+* 文字字体
+
+你也可以将其与你的 Imgur 帐户集成。
+
+![Ksnip configuration options][5]
+
+### 用法
+
+Ksnip 提供了大量的[功能][6]。我最喜欢的 Ksnip 部分是它拥有我需要的所有注释工具（还有一个我没想到的工具！）。
+
+你可以使用以下注释：
+
+ * 钢笔
+ * 记号笔
+ * 矩形
+ * 椭圆
+ * 文字
+
+你还可以模糊区域来移除敏感信息。还有使用我最喜欢的新工具：用于在界面上表示步骤的带数字的点。
+
+### 关于作者
+
+我非常喜欢 Ksnip，因此我联系了作者 [Damir Porobic][7] 来了解有关该项目的更多信息。
+
+当我问到是什么启发了他编写 Ksnip 时，他说：
+
+> “几年前我从 Windows 切换到 Linux，却没有了在 Windows 中常用的 Windows Snipping Tool。当时的所有其他截图工具要么很大（很多按钮和复杂功能），要么缺少诸如注释等关键功能，所以我决定编写一个简单的 Windows Snipping Tool 克隆版，但是随着时间的流逝，它开始有越来越多的功能。“
+
+这正是我在评估截图工具时发现的。他花时间构建解决方案并免费共享给他人使用，这真是太好了。
+
+至于 Ksnip 的未来，Damir 希望添加全局快捷方式（至少对于 Windows 是这样）和用于新截图的选项卡，并允许该应用在后台运行。GitHub 上的功能请求列表也越来越多。
+
+### 帮助的方式
+
+Damir 最需要的是帮助开发 Ksnip。他和他的妻子很快就会有孩子了，所以他将没有太多的时间放在这个项目上。不过，他可以检查和接受拉取请求。
+
+此外，此项目还可以通过 Snap 、Flatpak 以及 MacOS 安装包、Windows 安装包等其他安装方式安装。如果你想提供帮助，请查看 Ksnip 的 README 的 [Contribution][8] 部分。
+
+* * *
+
+> 此文章最初发表在 [Agaric Tech Cooperative 的博客][9]上，并经允许重新发布。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/annotate-screenshots-linux-ksnip
+
+作者：[Clayton Dewey][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/cedewey
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/checklist_hands_team_collaboration.png?itok=u82QepPk (a checklist for a team)
+[2]: https://elementary.io/
+[3]: https://github.com/damirporobic/ksnip
+[4]: https://opensource.com/sites/default/files/uploads/ksnip.png (Ksnip screenshot)
+[5]: https://opensource.com/sites/default/files/uploads/ksnip-configuration.png (Ksnip configuration options)
+[6]: https://github.com/DamirPorobic/ksnip#features
+[7]: https://github.com/damirporobic/
+[8]: https://github.com/DamirPorobic/ksnip/blob/master/README.md#contribution
+[9]: https://agaric.coop/blog/annotate-screenshots-linux-ksnip
diff --git a/published/20191211 How to Find High CPU Consumption Processes in Linux.md b/published/20191211 How to Find High CPU Consumption Processes in Linux.md
new file mode 100644
index 0000000000..69516fa8b8
--- /dev/null
+++ b/published/20191211 How to Find High CPU Consumption Processes in Linux.md
@@ -0,0 +1,166 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11678-1.html)
+[#]: subject: (How to Find High CPU Consumption Processes in Linux)
+[#]: via: (https://www.2daygeek.com/how-to-find-high-cpu-consumption-processes-in-linux/)
+[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
+
+如何在 Linux 中找出 CPU 占用高的进程
+======
+
+
+
+在之前的文章中我们已经讨论过 [如何在 Linux 中找出内存消耗最大的进程][1]。你可能也会遇到在 Linux 系统中找出 CPU 占用高的进程的情形。如果是这样，那么你需要列出系统中 CPU 占用高的进程列表来确定。我认为只有两种方法能实现：使用 [top 命令][2] 和 [ps 命令][3]。出于一些理由，我更倾向于用 `top` 命令而不是 `ps` 命令。但是两个工具都能达到你要的目的，所以你可以根据需求决定使用哪个。这两个工具都被 Linux 系统管理员广泛使用。
+
+### 1) 怎样使用 top 命令找出 Linux 中 CPU 占用高的进程
+
+在所有监控 Linux 系统性能的工具中，Linux 的 `top` 命令是最好的也是最知名的一个。`top` 命令提供了 Linux 系统运行中的进程的动态实时视图。它能显示系统的概览信息和 Linux 内核当前管理的进程列表。它显示了大量的系统信息，如 CPU 使用、内存使用、交换内存、运行的进程数、目前系统开机时间、系统负载、缓冲区大小、缓存大小、进程 PID 等等。默认情况下，`top` 命令的输出结果按 CPU 占用进行排序，每 5 秒中更新一次结果。如果你想要一个更清晰的视图来更深入的分析结果，[以批处理模式运行 top 命令][4] 是最好的方法。同时，你需要 [理解 top 命令输出结果的含义][5] ，这样才能解决系统的性能问题。
+
+```
+# top -b | head -50
+
+top - 00:19:17 up 14:23, 1 user, load average: 2.46, 2.18, 1.97
+Tasks: 306 total, 1 running, 305 sleeping, 0 stopped, 0 zombie
+%Cpu0 : 10.4 us, 3.0 sy, 0.0 ni, 83.9 id, 0.0 wa, 1.3 hi, 1.3 si, 0.0 st
+%Cpu1 : 17.0 us, 3.0 sy, 0.0 ni, 78.7 id, 0.0 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu2 : 13.0 us, 4.0 sy, 0.0 ni, 81.3 id, 0.0 wa, 0.3 hi, 1.3 si, 0.0 st
+%Cpu3 : 12.3 us, 3.3 sy, 0.0 ni, 82.5 id, 0.3 wa, 0.7 hi, 1.0 si, 0.0 st
+%Cpu4 : 12.2 us, 3.0 sy, 0.0 ni, 82.8 id, 0.7 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu5 : 6.4 us, 2.7 sy, 0.0 ni, 89.2 id, 0.0 wa, 0.7 hi, 1.0 si, 0.0 st
+%Cpu6 : 26.7 us, 3.4 sy, 0.0 ni, 68.6 id, 0.0 wa, 0.7 hi, 0.7 si, 0.0 st
+%Cpu7 : 15.6 us, 4.0 sy, 0.0 ni, 78.8 id, 0.0 wa, 0.7 hi, 1.0 si, 0.0 st
+KiB Mem : 16248556 total, 1448920 free, 8571484 used, 6228152 buff/cache
+KiB Swap: 17873388 total, 17873388 free, 0 used. 4596044 avail Mem
+PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
+ 2179 daygeek 20 3106324 613584 327564 S 79.5 3.8 14:19.76 Web Content
+ 1714 daygeek 20 4603372 974600 403504 S 20.2 6.0 65:18.91 firefox
+ 1227 daygeek 20 4192012 376332 180348 S 13.9 2.3 20:43.26 gnome-shell
+18324 daygeek 20 3296192 766040 127948 S 6.3 4.7 9:18.12 Web Content
+ 1170 daygeek 20 1008264 572036 546180 S 6.0 3.5 18:07.85 Xorg
+ 4684 daygeek 20 3363708 1.1g 1.0g S 3.6 7.2 13:49.92 VirtualBoxVM
+ 4607 daygeek 20 4591040 1.7g 1.6g S 3.0 11.0 14:09.65 VirtualBoxVM
+ 1211 daygeek 9 -11 2865268 21032 16588 S 2.0 0.1 10:46.37 pulseaudio
+ 4562 daygeek 20 1096888 28812 21044 S 1.7 0.2 4:42.93 VBoxSVC
+ 1783 daygeek 20 3123888 376896 134788 S 1.3 2.3 39:32.56 Web Content
+ 3286 daygeek 20 3089736 404088 184968 S 1.0 2.5 41:57.44 Web Content
+```
+
+上面的命令的各部分解释：
+
+ * `top`：命令
+ * `-b`：批次档模式
+ * `head -50`：显示输出结果的前 50 个
+ * `PID`：进程的 ID
+ * `USER`：进程的归属者
+ * `PR`：进程的等级
+ * `NI`：进程的 NICE 值
+ * `VIRT`：进程使用的虚拟内存
+ * `RES`：进程使用的物理内存
+ * `SHR`：进程使用的共享内存
+ * `S`：这个值表示进程的状态: `S` = 睡眠，`R` = 运行，`Z` = 僵尸进程
+ * `%CPU`：进程占用的 CPU 比例
+ * `%MEM`：进程使用的 RAM 比例
+ * `TIME+`：进程运行了多长时间
+ * `COMMAND`：进程名字
+
+如果你想看命令的完整路径而不是命令名字，以运行下面的格式 `top` 命令：
+
+```
+# top -c -b | head -50
+
+top - 00:28:49 up 14:33, 1 user, load average: 2.43, 2.49, 2.23
+Tasks: 305 total, 1 running, 304 sleeping, 0 stopped, 0 zombie
+%Cpu0 : 11.7 us, 3.7 sy, 0.0 ni, 82.3 id, 0.0 wa, 1.0 hi, 1.3 si, 0.0 st
+%Cpu1 : 13.6 us, 3.3 sy, 0.0 ni, 81.1 id, 0.7 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu2 : 10.9 us, 2.6 sy, 0.0 ni, 85.1 id, 0.0 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu3 : 16.0 us, 2.6 sy, 0.0 ni, 80.1 id, 0.0 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu4 : 9.2 us, 3.6 sy, 0.0 ni, 85.9 id, 0.0 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu5 : 15.6 us, 2.9 sy, 0.0 ni, 80.5 id, 0.0 wa, 0.3 hi, 0.7 si, 0.0 st
+%Cpu6 : 11.6 us, 4.3 sy, 0.0 ni, 82.7 id, 0.0 wa, 0.3 hi, 1.0 si, 0.0 st
+%Cpu7 : 8.0 us, 3.0 sy, 0.0 ni, 87.3 id, 0.0 wa, 0.7 hi, 1.0 si, 0.0 st
+KiB Mem : 16248556 total, 1022456 free, 8778508 used, 6447592 buff/cache
+KiB Swap: 17873388 total, 17873388 free, 0 used. 4201560 avail Mem
+PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
+18527 daygeek 20 3151820 624808 325748 S 52.8 3.8 59:26.72 /usr/lib/firefox/firefox -contentproc -childID 18 -isForBrowser -prefsLen 10002 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /+
+ 1714 daygeek 20 4764668 910940 443228 S 21.5 5.6 68:59.33 /usr/lib/firefox/firefox --new-window
+ 1227 daygeek 20 4193108 377344 181404 S 11.6 2.3 21:47.36 /usr/bin/gnome-shell
+ 1170 daygeek 20 1008820 572700 546844 S 5.6 3.5 19:05.10 /usr/lib/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -verbose 3
+18324 daygeek 20 3300288 789344 127948 S 5.0 4.9 9:46.89 /usr/lib/firefox/firefox -contentproc -childID 16 -isForBrowser -prefsLen 10002 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /+
+ 4684 daygeek 20 3363708 1.1g 1.0g S 3.6 7.2 14:10.18 /usr/lib/virtualbox/VirtualBoxVM --comment CentOS7 --startvm 002f47b8-2af2-48f5-be1d-67b67e03514c --no-startvm-errormsgbox
+ 4607 daygeek 20 4591040 1.7g 1.6g S 3.0 11.0 14:28.86 /usr/lib/virtualbox/VirtualBoxVM --comment Ubuntu-18.04 --startvm e8c32dbb-8b01-41b0-977a-bf28b9db1117 --no-startvm-errormsgbox
+ 1783 daygeek 20 3132640 451924 132168 S 2.6 2.8 39:49.66 /usr/lib/firefox/firefox -contentproc -childID 1 -isForBrowser -prefsLen 1 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/l+
+ 1211 daygeek 9 -11 2865268 21272 16828 S 2.0 0.1 11:01.29 /usr/bin/pulseaudio --daemonize=no
+ 4562 daygeek 20 1096888 28812 21044 S 1.7 0.2 4:49.33 /usr/lib/virtualbox/VBoxSVC --auto-shutdown
+16865 daygeek 20 3073364 430596 124652 S 1.3 2.7 8:04.02 /usr/lib/firefox/firefox -contentproc -childID 15 -isForBrowser -prefsLen 10002 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /+
+ 2179 daygeek 20 2945348 429644 172940 S 1.0 2.6 15:20.90 /usr/lib/firefox/firefox -contentproc -childID 6 -isForBrowser -prefsLen 7821 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /us+
+```
+
+### 2) 怎样使用 ps 命令找出 Linux 中 CPU 占用高的进程
+
+`ps` 是进程状态的缩写，它能显示系统中活跃的/运行中的进程的信息。它提供了当前进程及其详细信息，诸如用户名、用户 ID、CPU 使用率、内存使用、进程启动日期时间、命令名等等的快照。
+
+```
+# ps -eo pid,ppid,%mem,%cpu,cmd --sort=-%cpu | head
+
+ PID PPID %MEM %CPU CMD
+18527 1714 4.2 40.3 /usr/lib/firefox/firefox -contentproc -childID 18 -isForBrowser -prefsLen 10002 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 1714 true tab
+ 1714 1152 5.6 8.0 /usr/lib/firefox/firefox --new-window
+18324 1714 4.9 6.3 /usr/lib/firefox/firefox -contentproc -childID 16 -isForBrowser -prefsLen 10002 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 1714 true tab
+ 3286 1714 2.0 5.1 /usr/lib/firefox/firefox -contentproc -childID 14 -isForBrowser -prefsLen 8078 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 1714 true tab
+ 1783 1714 3.0 4.5 /usr/lib/firefox/firefox -contentproc -childID 1 -isForBrowser -prefsLen 1 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 1714 true tab
+ 1227 1152 2.3 2.5 /usr/bin/gnome-shell
+ 1170 1168 3.5 2.2 /usr/lib/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -verbose 3
+16865 1714 2.5 2.1 /usr/lib/firefox/firefox -contentproc -childID 15 -isForBrowser -prefsLen 10002 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 1714 true tab
+ 2179 1714 2.7 1.8 /usr/lib/firefox/firefox -contentproc -childID 6 -isForBrowser -prefsLen 7821 -prefMapSize 213431 -parentBuildID 20191031132559 -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 1714 true tab
+```
+
+上面的命令的各部分解释：
+
+ * `ps`：命令名字
+ * `-e`：选择所有进程
+ * `-o`：自定义输出格式
+ * `–sort=-%cpu`：基于 CPU 使用率对输出结果排序
+ * `head`：显示结果的前 10 行
+ * `PID`：进程的 ID
+ * `PPID`：父进程的 ID
+ * `%MEM`：进程使用的 RAM 比例
+ * `%CPU`：进程占用的 CPU 比例
+ * `Command`：进程名字
+
+如果你只想看命令名字而不是命令的绝对路径，以运行下面的格式 `ps` 命令：
+
+```
+# ps -eo pid,ppid,%mem,%cpu,comm --sort=-%cpu | head
+
+ PID PPID %MEM %CPU COMMAND
+18527 1714 4.1 40.4 Web Content
+ 1714 1152 5.7 8.0 firefox
+18324 1714 4.9 6.3 Web Content
+ 3286 1714 2.0 5.1 Web Content
+ 1783 1714 3.0 4.5 Web Content
+ 1227 1152 2.3 2.5 gnome-shell
+ 1170 1168 3.5 2.2 Xorg
+16865 1714 2.4 2.1 Web Content
+ 2179 1714 2.7 1.8 Web Content
+```
+
+--------------------------------------------------------------------------------
+
+via: https://www.2daygeek.com/how-to-find-high-cpu-consumption-processes-in-linux/
+
+作者：[Magesh Maruthamuthu][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.2daygeek.com/author/magesh/
+[b]: https://github.com/lujun9972
+[1]: https://linux.cn/article-11542-1.html
+[2]: https://www.2daygeek.com/linux-top-command-linux-system-performance-monitoring-tool/
+[3]: https://www.2daygeek.com/linux-ps-command-find-running-process-monitoring/
+[4]: https://www.2daygeek.com/linux-run-execute-top-command-in-batch-mode/
+[5]: https://www.2daygeek.com/understanding-linux-top-command-output-usage/
diff --git a/published/20191212 How to configure Openbox for your Linux desktop.md b/published/20191212 How to configure Openbox for your Linux desktop.md
new file mode 100644
index 0000000000..d400c04d36
--- /dev/null
+++ b/published/20191212 How to configure Openbox for your Linux desktop.md
@@ -0,0 +1,69 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11698-1.html)
+[#]: subject: (How to configure Openbox for your Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/openbox-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+如何为 Linux 桌面配置 Openbox
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。Openbox 窗口管理器占用很小的系统资源、易于配置、使用愉快。
+
+
+
+你可能不知道你使用过 [Openbox][2] 桌面：尽管 Openbox 本身是一个出色的窗口管理器，但它还是 LXDE 和 LXQT 等桌面环境的窗口管理器“引擎”，它甚至可以管理 KDE 和 GNOME。除了作为多个桌面的基础之外，Openbox 可以说是最简单的窗口管理器之一，可以为那些不想学习那么多配置选项的人配置。通过使用基于菜单的 obconf 的配置应用，可以像在 GNOME 或 KDE 这样的完整桌面中一样轻松地设置所有常用首选项。
+
+### 安装 Openbox
+
+你可能会在 Linux 发行版的软件仓库中找到 Openbox，也可以在 [Openbox.org][3] 中找到它。如果你已经在运行其他桌面，那么可以安全地在同一系统上安装 Openbox，因为 Openbox 除了几个配置面板之外，不包括任何捆绑的应用。
+
+安装后，退出当前桌面会话，以便你可以登录 Openbox 桌面。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，这取决于你的设置）将继续登录到以前的桌面，因此你必须在登录之前覆盖该选择。
+
+要使用 GDM 覆盖它：
+
+![Select your desktop session in GDM][4]
+
+要使用 SDDM 覆盖它：
+
+![Select your desktop session with KDM][5]
+
+### 配置 Openbox 桌面
+
+默认情况下，Openbox 包含 obconf 应用，你可以使用它来选择和安装主题、修改鼠标行为、设置桌面首选项等。你可能会在仓库中发现其他配置应用，如 obmenu，用于配置窗口管理器的其他部分。
+
+![Openbox Obconf configuration application][6]
+
+构建你自己的桌面环境相对容易。它有一些所有常见的桌面组件，例如系统托盘 [stalonetray][7]、任务栏 [Tint2][8] 或 [Xfce4-panel][9] 等几乎你能想到的。任意组合应用，直到拥有梦想的开源桌面为止。
+
+![Openbox][10]
+
+### 为何使用 Openbox
+
+Openbox 占用的系统资源很小、易于配置、使用起来很愉悦。它基本不会让你感觉到阻碍，会是一个容易熟悉的系统。你永远不会知道你面前的桌面环境秘密使用了 Openbox 作为窗口管理器（知道如何自定义它会不会很高兴？）。如果开源吸引你，那么试试看 Openbox。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/openbox-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc_general_openfield.png?itok=MeVN97oy (open with sky and grass)
+[2]: http://openbox.org
+[3]: http://openbox.org/wiki/Openbox:Download
+[4]: https://opensource.com/sites/default/files/advent-gdm_0.jpg (Select your desktop session in GDM)
+[5]: https://opensource.com/sites/default/files/advent-kdm.jpg (Select your desktop session with KDM)
+[6]: https://opensource.com/sites/default/files/uploads/advent-openbox-obconf_675px.jpg (Openbox Obconf configuration application)
+[7]: https://sourceforge.net/projects/stalonetray/
+[8]: https://opensource.com/article/19/1/productivity-tool-tint2
+[9]: http://xfce.org
+[10]: https://opensource.com/sites/default/files/uploads/advent-openbox_675px.jpg (Openbox)
diff --git a/published/20191213 What GNOME 2 fans love about the Mate Linux desktop.md b/published/20191213 What GNOME 2 fans love about the Mate Linux desktop.md
new file mode 100644
index 0000000000..61f485fc27
--- /dev/null
+++ b/published/20191213 What GNOME 2 fans love about the Mate Linux desktop.md
@@ -0,0 +1,56 @@
+[#]: collector: (lujun9972)
+[#]: translator: (mayunmeiyouming)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11703-1.html)
+[#]: subject: (What GNOME 2 fans love about the Mate Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/mate-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+GNOME 2 粉丝喜欢 Mate Linux 桌面的什么？
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。如果你还在怀念 GNOME 2，那么 Mate Linux 桌面将满足你的怀旧情怀。
+
+
+
+如果你以前听过这个传闻：当 GNOME3 第一次发布时，很多 GNOME 用户还没有准备好放弃 GNOME 2。[Mate][2]（以马黛茶植物命名）项目的开始是为了延续 GNOME 2 桌面，刚开始时它使用 GTK 2（GNOME 2 所基于的工具包），然后又合并了 GTK 3。由于 Linux Mint 的简单易用，使得该桌面变得非常流行，并且从那时起，它已经普遍用于 Fedora、Ubuntu、Slackware、Arch 和许多其他 Linux 发行版上。今天，Mate 继续提供一个传统的桌面环境，它的外观和感觉与 GNOME 2 完全一样，使用 GTK 3 工具包。
+
+你可以在你的 Linux 发行版的软件仓库中找到 Mate，也可以下载并[安装][3]一个把 Mate 作为默认桌面的发行版。不过，在你这样做之前，请注意为了提供完整的桌面体验，所以许多 Mate 应用程序都是随该桌面一起安装的。如果你运行的是不同的桌面，你可能会发现自己有多余的应用程序（两个 PDF 阅读器、两个媒体播放器、两个文件管理器，等等）。所以如果你只想尝试 Mate 桌面，可以在虚拟机（例如 [GNOME box][4]）中安装基于 Mate 的发行版。
+
+### Mate 桌面之旅
+
+Mate 项目不仅仅可以让你想起来 GNOME 2；它就是 GNOME 2。如果你是 00 年代中期 Linux 桌面的粉丝，至少，你会从中感受到 Mate 的怀旧情怀。我不是 GNOME 2 的粉丝，我更倾向于使用 KDE，但是有一个地方我无法想象没有 GNOME 2：[OpenSolaris][5]。OpenSolaris 项目并没有持续太久，在 Sun Microsystems 被并入 Oracle 之前，Ian Murdock 加入 Sun 时它就显得非常突出，我当时是一个初级的 Solaris 管理员，使用 OpenSolaris 来让自己更多学会那种 Unix 风格。这是我使用过 GNOME 2 的唯一平台（因为我一开始不知道如何更改桌面，后来习惯了它），而今天的 [OpenIndiana project][6] 是 OpenSolaris 的社区延续，它通过 Mate 桌面使用 GNOME 2。
+
+![Mate on OpenIndiana][7]
+
+Mate 的布局由左上角的三个菜单组成：应用程序、位置和系统。应用程序菜单提供对系统上安装的所有的应用程序启动器的快速访问。位置菜单提供对常用位置（如家目录、网络文件夹等）的快速访问。系统菜单包含全局选项，如关机和睡眠。右上角是一个系统托盘，屏幕底部有一个任务栏和一个虚拟桌面切换栏。
+
+就桌面设计而言，这是一种稍微有点奇怪的配置。它从早期的 Linux 桌面、MacFinder 和 Windows 中借用了一些相同的部分，但是又创建了一个独特的配置，这种配置很直观而有些熟悉。Mate 执意保持这个模型，而这正是它的用户喜欢的地方。
+
+### Mate 和开源
+
+Mate 是一个最直接的例子，展示了开源如何使开发人员能够对抗项目生命的终结。从理论上讲，GNOME 2 会被 GNOME 3 所取代，但它依然存在，因为一个开发人员建立了该代码的一个分支并继续发展了下去。它的发展势头越来越庞大，更多的开发人员加入进来，并且这个让用户喜爱的桌面比以往任何时候都要更好。并不是所有的软件都有第二次机会，但是开源永远是一个机会，否则就永远没有机会。
+
+使用和支持开源意味着支持用户和开发人员的自由。而且 Mate 桌面是他们的努力的有力证明。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/mate-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[mayunmeiyouming](https://github.com/mayunmeiyouming)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/linux_keyboard_desktop.png?itok=I2nGw78_ (Linux keys on the keyboard for a desktop computer)
+[2]: https://mate-desktop.org/
+[3]: https://mate-desktop.org/install/
+[4]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[5]: https://en.wikipedia.org/wiki/OpenSolaris
+[6]: https://www.openindiana.org/documentation/faq/#what-is-openindiana
+[7]: https://opensource.com/sites/default/files/uploads/advent-mate-openindiana_675px.jpg (Mate on OpenIndiana)
diff --git a/published/20191214 Get started with Lumina for your Linux desktop.md b/published/20191214 Get started with Lumina for your Linux desktop.md
new file mode 100644
index 0000000000..213e4eff5b
--- /dev/null
+++ b/published/20191214 Get started with Lumina for your Linux desktop.md
@@ -0,0 +1,69 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11706-1.html)
+[#]: subject: (Get started with Lumina for your Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/linux-lumina-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+在 Linux 桌面中开始使用 Lumina
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。Lumina 桌面是让你使用快速、合理的基于 Fluxbox 桌面的捷径，它具有你无法缺少的所有功能。
+
+
+
+多年来，有一个名为 PC-BSD 的基于 FreeBSD 的桌面操作系统（OS）。它旨在作为一个常规使用的系统，因此值得注意，因为 BSD 主要用于服务器。大多数时候，PC-BSD 默认带 KDE 桌面，但是 KDE 越来越依赖于 Linux 特定的技术，因此 PC-BSD 越来越从 KDE 迁离。PC-BSD 变成了 [Trident][2]，它的默认桌面是 [Lumina][3]，它是一组小部件，它们使用与 KDE 相同的基于 Qt 的工具包，运行在 Fluxbox 窗口管理器上。
+
+你可以在 Linux 发行版的软件仓库或 BSD 的 ports 树中找到 Lumina 桌面。如果你安装了 Lumina 并且已经在运行另一个桌面，那么你可能会发现有冗余的应用（两个 PDF 阅读器、两个文件管理器，等等），因为 Lumina 包含一些集成的应用。如果你只想尝试 Lumina 桌面，那么可以在虚拟机如 [GNOME Boxes][4] 中安装基于 Lumina 的 BSD 发行版。
+
+如果在当前的操作系统上安装 Lumina，那么必须注销当前的桌面会话，才能登录到新的会话。默认情况下，会话管理器（SDDM、GDM、LightDM 或 XDM，取决于你的设置）将继续登录到以前的桌面，因此你必须在登录之前覆盖该桌面。
+
+在 GDM 中：
+
+![Selecting your desktop in GDM][5]
+
+在 SDDM 中：
+
+![Selecting your desktop in KDM][6]
+
+### Lumina 桌面
+
+Lumina 提供了一个简单而轻巧的桌面环境。屏幕底部有一个面板，它的左侧是应用菜单，中间是任务栏，右边是系统托盘。桌面上有图标，可以快速访问常见的应用和路径。
+
+除了这个基本的桌面结构外，Lumina 还有自定义文件管理器、PDF 查看器，截图工具、媒体播放器、文本编辑器和存档工具。还有一个配置程序可以帮助你自定义 Lumina 桌面，并且右键单击桌面可以找到更多配置选项。
+
+![Lumina desktop running on Project Trident][7]
+
+Lumina 与几个 Linux 轻量级桌面非常相似，尤其是 LXQT，不同之处在于 Lumina 完全不依赖于基于 Linux 的桌面框架（例如 ConsoleKit、PolicyKit、D-Bus 或 systemd）。对于你而言，这是否具有优势取决于所运行的操作系统。毕竟，如果你运行的是可以访问这些功能的 Linux，那么使用不使用这些特性的桌面可能就没有多大意义，还会减少功能。如果你运行的是 BSD，那么在 Fluxbox 中运行 Lumina 部件意味着你不必从 ports 安装 Linux 兼容库。
+
+### 为什么要使用 Lumina
+
+Lumina 设计简单，它没有很多功能，但是你可以安装 Fluxbox 你喜欢的组件（用于文件管理的 [PCManFM][8]、各种 [LXQt 应用][9]、[Tint2][10] 面板等）。在开源中，开源用户喜欢寻找不要重复发明轮子的方法（几乎与我们喜欢重新发明轮子一样多）。
+
+Lumina 桌面是让你使用快速、合理的基于 Fluxbox 桌面的捷径，它具有你无法缺少的所有功能，并且你很少需要调整细节。试一试 Lumina 桌面，看看它是否适合你。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-lumina-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/lightbulb-idea-think-yearbook-lead.png?itok=5ZpCm0Jh (Lightbulb)
+[2]: https://project-trident.org/
+[3]: https://lumina-desktop.org/
+[4]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[5]: https://opensource.com/sites/default/files/uploads/advent-gdm_400x400_1.jpg (Selecting your desktop in GDM)
+[6]: https://opensource.com/sites/default/files/uploads/advent-kdm_400x400_1.jpg (Selecting your desktop in KDM)
+[7]: https://opensource.com/sites/default/files/uploads/advent-lumina.jpg (Lumina desktop running on Project Trident)
+[8]: https://wiki.lxde.org/en/PCManFM
+[9]: http://lxqt.org
+[10]: https://opensource.com/article/19/1/productivity-tool-tint2
diff --git a/published/20191217 Build a retro Apple desktop with the Linux MLVWM.md b/published/20191217 Build a retro Apple desktop with the Linux MLVWM.md
new file mode 100644
index 0000000000..6aee6a3fec
--- /dev/null
+++ b/published/20191217 Build a retro Apple desktop with the Linux MLVWM.md
@@ -0,0 +1,207 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11720-1.html)
+[#]: subject: (Build a retro Apple desktop with the Linux MLVWM)
+[#]: via: (https://opensource.com/article/19/12/linux-mlvwm-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+使用 Linux MLVWM 打造复古苹果桌面
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。如果老式的苹果电脑是用开源 POSIX 构建的呢？你可以通过构建 Macintosh 式的虚拟窗口管理器来实现。
+
+![Person typing on a 1980's computer][1]
+
+想象一下穿越到另一段平行历史，Apple II GS 和 MacOS 7 是基于开源 [POSIX][2] 构建的，它使用了与现代 Linux 相同的所有惯例，例如纯文本配置文件和模块化系统设计。这样的操作系统将为其用户带来什么？你可以使用 [Macintosh 式的虚拟窗口管理器（MLVWM）][3]来回答这些问题（甚至更多！）。
+
+![MLVWM running on Slackware 14.2][4]
+
+### 安装 MLVWM
+
+MLVWM 安装并不容易，并且可能不在你的发行版软件仓库中。如果你有时间理解翻译不佳的 README 文件，编辑一些配置文件，收集并调整一些旧的 .xpm 图片，编辑一两个 Xorg 选项，那么你就可以体验 MLVWM。不管怎么说，这是一个新奇的窗口管理器，其最新版本可以追溯到 2000 年。
+
+要编译 MLVWM，你必须安装 imake，它提供了 `xmkmf` 命令。你可以从发行版的软件仓库中安装 imake，也可以直接从 [Freedesktop.org][5] 获得。假设你已经有 `xmkmf` 命令，请进入包含 MLVWM 源码的目录，然后运行以下命令进行构建：
+
+```
+$ xmkmf -a
+$ make
+```
+
+构建后，编译后的 `mlvwm` 二进制文件位于 `mlvwm` 目录中。将其移动到[你的 PATH][6] 的任何位置：
+
+```
+$ mv mlvwm/mlvwm /usr/local/bin/
+```
+
+#### 编辑配置文件
+
+现在已经安装好 MLVWM，但是如果不调整几个配置文件并仔细放好所需的图像文件，它将无法正确启动。示例配置文件位于你下载的源代码的 `sample_rc` 目录中。将文件 `Mlvwm-Netscape` 和 `Mlvwm-Xterm` 复制到你的主目录：
+
+```
+$ cp sample_rc/Mlvwm-{Netscape,Xterm} $HOME
+```
+
+将 `Mlvwmrc` 改名为 `$HOME/.mlvwmrc`（是的，即使示例文件的名称看似是大写字母，但你也必须使用小写的 “m”）：
+
+```
+$ cp sample_rc/Mlvwmrc $HOME/.mlvwmrc
+```
+
+打开 `.mlwmrc` 并找到第 54-55 行，它们定义了 MLVWM 在菜单和 UI 中使用的像素图的路径（`IconPath`）：
+
+```
+# Set icon search path. It needs before "Style".
+IconPath /usr/local/include/X11/pixmaps:/home2/tak/bin/pixmap
+```
+
+调整路径以匹配你填充图像的路径（我建议使用 `$HOME/.local/share/pixmaps`）。MLVWM 不提供像素图，因此需要你提供构建桌面所需图标。
+
+即使你有位于系统其他位置的像素图（例如 `/usr/share/pixmaps`），也要这样做，因为你需要调整像素图的大小，你可能也不想在系统范围内执行此操作。
+
+```
+# Set icon search path. It needs before "Style".
+IconPath /home/seth/.local/share/pixmaps
+```
+
+#### 选择像素图
+
+你已将 `.local/share/pixmaps` 目录定义为像素图源路径，但是该目录和图像均不存在。创建目录：
+
+```
+$ mkdir -p $HOME/.local/share/pixmaps
+```
+
+现在，配置文件将图像分配给菜单项和 UI 元素，但是系统中不存在这些图像。要解决此问题，请通读配置文件并找到每个 .xpm 图像。对于配置中列出的每个图像，将具有相同文件名的图像（或更改配置文件中的文件名）添加到你的 IconPath 目录。
+
+`.mlvwmrc` 文件的注释很好，因此你可以大致了解要编辑的内容。无论如何，这只是第一步。你可以随时回来更改桌面外观。
+
+这有些例子。
+
+此代码块设置屏幕左上角的图标：
+
+```
+# Register the menu
+Menu Apple, Icon label1.xpm, Stick
+```
+
+`label1.xpm` 图像实际上在源代码的 `pixmap` 目录中，但我更喜欢使用来自 `/usr/share/pixmaps` 的 `Penguin.xpm`（在 Slackware 上）。无论使用什么，都必须将自定义像素图放在 `~/.local/share/pixmaps` 中，并在配置中更改像素图的名称，或者重命名像素图以匹配配置文件中当前的名称。
+
+此代码块定义了左侧菜单中列出的应用：
+
+```
+"About this Workstation..." NonSelect, Gray, Action About
+"" NonSelect
+"Terminal" Icon mini-display.xpm, Action Exec "kterm" exec kterm -ls
+"Editor" Action Exec "mule" exec mule, Icon mini-edit.xpm
+"calculator" Action Exec "xcal" exec xcalc, Icon mini-calc.xpm
+END
+```
+
+通过遵循与配置文件中相同的语法，你可以自定义像素图并将自己的应用添加到菜单中（例如，我将 `mule` 更改为 `emacs`）。这是你在 MLVWM GUI 中打开应用的入口，因此请列出你要快速访问的所有内容。你可能还希望包括指向 `/usr/share/applications` 文件夹的快捷方式。
+
+```
+"Applications" Icon Penguin.xpm, Action Exec "thunar /usr/share/applications" exec thunar /usr/share/applications
+```
+
+完成编辑配置文件并将自己的图像添加到 IconPath 目录后，必须将所有像素图的大小都调整为大约 16x16 像素。（MLVWM 的默认设置不一致，因此存在变化空间。）你可以使用 ImageMagick 进行批量操作：
+
+```
+$ for i in ~/.local/share/mlvwm-pixmaps/*xpm ; do convert -resize '16x16^' $i; done
+```
+
+### 启动 MLVWM
+
+最简单的运行 MLVWM 的方式是让 Xorg 完成大部分工作。首先，你必须创建一个 `$HOME/.xinitrc` 文件。我从 Slackware 复制了这个，它也是从 Xorg 拿来的：
+
+```
+#!/bin/sh
+# $XConsortium: xinitrc.cpp,v 1.4 91/08/22 11:41:34 rws Exp $
+
+userresources=$HOME/.Xresources
+usermodmap=$HOME/.Xmodmap
+sysresources=/etc/X11/xinit/.Xresources
+sysmodmap=/etc/X11/xinit/.Xmodmap
+
+# merge in defaults and keymaps
+
+if [ -f $sysresources ]; then
+ xrdb -merge $sysresources
+fi
+
+if [ -f $sysmodmap ]; then
+ xmodmap $sysmodmap
+fi
+
+if [ -f $userresources ]; then
+ xrdb -merge $userresources
+fi
+
+if [ -f $usermodmap ]; then
+ xmodmap $usermodmap
+fi
+
+# Start the window manager:
+if [ -z "$DESKTOP_SESSION" -a -x /usr/bin/ck-launch-session ]; then
+ exec ck-launch-session /usr/local/bin/mlvwm
+else
+ exec /usr/local/bin/mlvwm
+fi
+```
+
+根据此文件，`startx` 命令的默认操作是启动 MLVWM。但是，你的发行版可能对于图形服务器启动（或被终止以重新启动）时会发生的情况有其他做法，因此此文件可能对你没有什么帮助。在许多发行版上，你可以添加 .desktop 文件到 `/usr/share/xsessions` 中，以将其列在 GDM 或 KDM 菜单中，因此创建名为 `mlvwm.desktop` 的文件并输入：
+
+```
+[Desktop Entry]
+Name=Mlvwm
+Comment=Macintosh-like virtual window manager
+Exec=/usr/local/bin/mlvwm
+TryExec=ck-launch-session /usr/local/bin/mlvwm
+Type=Application
+```
+
+从桌面会话注销并重新登录到 MLVWM。默认情况下，会话管理器（KDM、GDM 或 LightDM，具体取决于你的设置）将继续登录到以前的桌面，因此在登录之前必须覆盖它。
+
+对于 GDM：
+
+![][7]
+
+对于 SDDM：
+
+![][8]
+
+#### 强制启动
+
+如果 MLVWM 无法启动，请尝试安装 XDM，这是一个轻量级会话管理器，它不会查询 `/usr/share/xsessions` 的内容，而是执行经过身份验证用户的所有 `.xinitrc` 操作。
+
+![MLVWM][9]
+
+### 打造自己的复古苹果
+
+MLVWM 桌面未经打磨、不完美、模仿到位且充满乐趣。你看到的许多菜单项都是未实现的，但你可以使它们变得活跃且有意义。
+
+这是一次让你时光倒流、改变历史，让老式苹果系列电脑成为开源堡垒的机会。成为一名修正主义者，设计你自己的复古苹果桌面，最重要的是，它有乐趣。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-mlvwm-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/1980s-computer-yearbook.png?itok=eGOYEKK- (Person typing on a 1980's computer)
+[2]: https://opensource.com/article/19/7/what-posix-richard-stallman-explains
+[3]: http://www2u.biglobe.ne.jp/~y-miyata/mlvwm.html
+[4]: https://opensource.com/sites/default/files/uploads/advent-mlvwm-file.jpg (MLVWM running on Slackware 14.2)
+[5]: http://cgit.freedesktop.org/xorg/util/imake
+[6]: https://opensource.com/article/17/6/set-path-linux
+[7]: https://opensource.com/sites/default/files/advent-gdm_2.jpg
+[8]: https://opensource.com/sites/default/files/advent-kdm_1.jpg
+[9]: https://opensource.com/sites/default/files/uploads/advent-mlvwm-chess.jpg (MLVWM)
diff --git a/published/20191218 How tracking pixels work.md b/published/20191218 How tracking pixels work.md
new file mode 100644
index 0000000000..5a47b5197f
--- /dev/null
+++ b/published/20191218 How tracking pixels work.md
@@ -0,0 +1,131 @@
+[#]: collector: (lujun9972)
+[#]: translator: (chen-ni)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11721-1.html)
+[#]: subject: (How tracking pixels work)
+[#]: via: (https://jvns.ca/blog/how-tracking-pixels-work/)
+[#]: author: (Julia Evans https://jvns.ca/)
+
+网络广告商的像素追踪是如何工作的？
+======
+
+
+
+昨天，我和一名记者谈到了一个问题：广告商是如何在互联网上对人们进行追踪的？我们津津有味地查看了 Firefox 的开发者工具（虽然我不是一个互联网隐私专家，但至少还会使用开发者工具中的“network”标签页），从中我终于弄明白像素追踪在实际中是如何工作的了。
+
+### 问题：Facebook 怎么知道你逛了 Old Navy？
+
+我时常听人们说起这种有些诡异的上网经历：你在线上浏览了一个商品，一天之后，竟然看到了同一款靴子（或者是别的什么你当时浏览的商品）的广告。这就是所谓的“再营销”，但它到底是如何实现的呢？
+
+在本文中，我们来进行一个小实验，看看 Facebook 究竟是怎么知道你在线上浏览了什么商品的。这里使用 Facebook 作为示例，只是因为很容易找到使用了 Facebook 像素追踪技术的网站；其实，几乎所有互联网广告公司都会使用类似的追踪技术。
+
+### 准备：允许第三方追踪器，同时关闭广告拦截器
+
+我使用的浏览器是 Firefox，但是 Firefox 默认拦截了很多这种类型的追踪，所以需要修改 Firefox 的隐私设置，才能让这种追踪生效。
+
+首先，我将隐私设置从默认设置（[截图][1]）修改为允许第三方追踪器的个性化设置（[截图][2]），然后禁用了一些平时运行的隐私保护扩展。
+
+![截图][1]
+
+![截图][2]
+
+### 像素追踪：关键不在于 gif，而在于请求参数
+
+像素追踪是网站用来追踪你的一个 1x1 大小的 gif。就其本身而言，一个小小的 1x1 gif 显然起不到什么作用。那么，像素追踪到底是如何进行追踪的？其中涉及两个方面：
+
+1. 通过使用像素追踪上的**请求参数**，网站可以添加额外的信息，比如你正在访问的页面。这样一来，请求的就不是 `https://www.facebook.com/tr/`（这个链接是一个 44 字节大小的 1x1 gif），而是 `https://www.facebook.com/tr/?the_website_you're_on`。（邮件营销人员会使用类似的技巧，通过为像素追踪指定一个独特的 URL，弄清楚你是否打开了某一封邮件。）
+2. 在发送该请求的同时，还发送了相应的 cookie。这样一来广告商就可以知道，访问 oldnavy.com 的这个人和在同一台电脑上使用 Facebook 的是同一个人。
+
+### Old Navy 网站上的 Facebook 像素追踪
+
+为了对此进行验证，我在 Old Navy（GAP 旗下的一个服装品牌）网站上浏览了一个商品，相应的 URL 是 `https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1`（这是一件“男款短绒格子花呢大衣”）。
+
+在我浏览这个商品的同时，页面上运行的 Javascript（用的应该是[这段代码][4]）向 facebook.com 发送了一个请求。在开发者工具中，该请求看上去是这样的：（我屏蔽了大部分 cookie 值，因为其中有一些是我的登录 cookie）
+
+![][5]
+
+下面对其进行拆解分析：
+
+1. 我的浏览器向如下 URL 发送了一个请求；
+
+ ```
+https://www.facebook.com/tr/?id=937725046402747&ev=PageView&dl=https%3A%2F%2Foldnavy.gap.com%2Fbrowse%2Fproduct.do%3Fpid%3D504753002%26cid%3D1125694%26pcid%3Dxxxxxx0%26vid%3D1%26grid%3Dpds_0_109_1%23pdp-page-content&rl=https%3A%2F%2Foldnavy.gap.com%2Fbrowse%2Fcategory.do%3Fcid%3D1135640%26mlink%3D5155%2Cm_mts_a&if=false&ts=1576684838096&sw=1920&sh=1080&v=2.9.15&r=stable&a=tmtealium&ec=0&o=30&fbp=fb.1.1576684798512.1946041422&it=15xxxxxxxxxx4&coo=false&rqm=GET
+```
+2. 与该请求同时发送的，还有一个名为 `fr` 的 cookie，取值为
+
+ ```
+10oGXEcKfGekg67iy.AWVdJq5MG3VLYaNjz4MTNRaU1zg.Bd-kxt.KU.F36.0.0.Bd-kx6.
+```
+（估计是我的 Facebook 广告追踪 ID）
+
+在所发送的像素追踪查询字符串里，有三个值得注意的地方：
+
+* 我当前访问的页面：`https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1#pdp-page-content`
+* 引导我来到当前页面的上一级页面：`https://oldnavy.gap.com/browse/category.do?cid=1135640&mlink=5155,m_mts_a`；
+* 作为我的身份标识的 cookie：`10oGXEcKfGekg67iy.AWVdJq5MG3VLYaNjz4MTNRaU1zg.Bd-kxt.KU.F36.0.0.Bd-kx6.`
+
+### 下面来逛逛 Facebook！
+
+下面来逛逛 Facebook 吧。我之前已经登入了 Facebook，猜猜看，我的浏览器发送给 Facebook 的 cookie 是什么？
+
+不出所料，正是之前见过的 `fr` cookie：`10oGXEcKfGekg67iy.AWVdJq5MG3VLYaNjz4MTNRaU1zg.Bd-kxt.KU.F36.0.0.Bd-kx6.`。Facebook 现在一定知道我（Julia Evans，这个 Facebook 账号所关联的人）在几分钟之前访问了 Old Navy 网站，并且浏览了“男款短绒格子花呢大衣”，因为他们可以使用这个 cookie 将数据串联起来。
+
+### 这里涉及到的是第三方 cookie
+
+Facebook 用来追踪我访问了哪些网站的 cookie，属于所谓的“第三方 cookie”，因为 Old Navy 的网站使用它为一个第三方（即 facebook.com）确认我的身份。这和用来维持登录状态的“第一方 cookie”有所不同。
+
+Safari 和 Firefox 默认都会拦截许多第三方 cookie（所以需要更改 Firefox 的隐私设置，才能够进行这个实验），而 Chrome 目前并不进行拦截（很可能是因为 Chrome 的所有者正是一个广告公司）。（LCTT 译注：Chrome 可以设置阻拦）
+
+### 网站上的像素追踪有很多
+
+如我所料，网站上的像素追踪有 **很多**。比如，wrangler.com 在我的浏览器里加载了来自不同域的 19 个不同的像素追踪。wrangler.com 上的像素追踪分别来自：`ct.pinterest.com`、`af.monetate.net`、`csm.va.us.criteo.net`、`google-analytics.com`、`dpm.demdex.net`、`google.ca`、`a.tribalfusion.com`、`data.photorank.me`、`stats.g.doubleclick.net`、`vfcorp.dl.sc.omtrdc.net`、`ib.adnxs.com`、`idsync.rlcdn.com`、`p.brsrvr.com`，以及 `adservice.google.com`。
+
+Firefox 贴心地指出，如果使用 Firefox 的标准隐私设置，其中的大部分追踪器都会被拦截：
+
+![][8]
+
+### 浏览器的重要性
+
+浏览器之所以如此重要，是因为你的浏览器最终决定了发送你的什么信息、发送到哪些网站。Old Navy 网站上的 Javascript 可以请求你的浏览器向 Facebook 发送关于你的追踪信息，但浏览器可以拒绝执行。浏览器的决定可以是：“哈，我知道 facebook.com/tr/ 是一个像素追踪，我不想让我的用户被追踪，所以我不会发送这个请求”。
+
+浏览器还可以允许用户对上述行为进行配置，方法包括更改浏览器设置，以及安装浏览器扩展（所以才会有如此多的隐私保护扩展）。
+
+### 摸清其中原理，实为一件趣事
+
+在我看来，弄清楚 cookie/像素追踪是怎么用于对你进行追踪的，实在是一件趣事（尽管有点吓人）。我之前大概明白其中的道理，但是并没有亲自查看过像素追踪上的 cookie，也没有看过发送的查询参数上究竟包含什么样的信息。
+
+当然，明白了其中的原理，也就更容易降低被追踪的概率了。
+
+### 可以采取的措施
+
+为了尽量避免在互联网上被追踪，我采取了几种简单的措施:
+
+* 安装一个广告拦截器（比如 ublock origin 之类）。广告拦截器可以针对许多追踪器的域进行拦截。
+* 使用目前默认隐私保护强度更高的 Firefox/Safari，而不是 Chrome。
+* 使用 [Facebook Container][9] 这个 Firefox 扩展。该扩展针对 Facebook 进一步采取了防止追踪的措施。
+
+虽然在互联网上被追踪的方式还有很多（尤其是在使用手机应用的时候，因为在这种情况下，你没有和像对浏览器一样的控制程度），但是能够理解这种追踪方法的工作原理，稍微减少一些被追踪的可能性，也总归是一件好事。
+
+--------------------------------------------------------------------------------
+
+via: https://jvns.ca/blog/how-tracking-pixels-work/
+
+作者：[Julia Evans][a]
+选题：[lujun9972][b]
+译者：[chen-ni](https://github.com/chen-ni)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://jvns.ca/
+[b]: https://github.com/lujun9972
+[1]: https://jvns.ca/images/trackers.png
+[2]: https://jvns.ca/images/firefox-insecure-settings.png
+[3]: https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1
+[4]: https://developers.facebook.com/docs/facebook-pixel/implementation/
+[5]: https://jvns.ca/images/fb-old-navy.png
+[6]: https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1#pdp-page-content
+[7]: https://oldnavy.gap.com/browse/category.do?cid=1135640&mlink=5155,m_mts_a
+[8]: https://jvns.ca/images/firefox-helpful.png
+[9]: https://addons.mozilla.org/en-CA/firefox/addon/facebook-container/
diff --git a/published/20191220 How to Start, Stop - Restart Services in Ubuntu and Other Linux Distributions.md b/published/20191220 How to Start, Stop - Restart Services in Ubuntu and Other Linux Distributions.md
new file mode 100644
index 0000000000..bcb25f74e6
--- /dev/null
+++ b/published/20191220 How to Start, Stop - Restart Services in Ubuntu and Other Linux Distributions.md
@@ -0,0 +1,179 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11722-1.html)
+[#]: subject: (How to Start, Stop & Restart Services in Ubuntu and Other Linux Distributions)
+[#]: via: (https://itsfoss.com/start-stop-restart-services-linux/)
+[#]: author: (Sergiu https://itsfoss.com/author/sergiu/)
+
+如何在 Ubuntu 和其他 Linux 发行版中启动、停止和重启服务
+======
+
+
+
+服务是必不可少的后台进程，它通常随系统启动，并在关机时关闭。如果你是系统管理员，那么你会定期处理服务。如果你是普通桌面用户，你可能会遇到需要重启服务的情况，例如[安装 Barrier 来用于在计算机之间共享鼠标和键盘][1]。或[在使用 ufw 设置防火墙][2]时。
+
+今天，我将向你展示两种管理服务的方式。你将学习在 Ubuntu 或任何其他 Linux 发行版中启动、停止和重启服务。
+
+> systemd 与 init
+>
+> 如今，Ubuntu 和许多其他发行版都使用 systemd 而不是旧的 init。
+>
+> 在 systemd 中，可以使用 `systemctl` 命令管理服务。
+>
+> 在 init 中，你可以使用 `service` 命令管理服务。
+>
+> 你会注意到，即使你的 Linux 系统使用 systemd，它仍然可以使用 `service` 命令（与 init 系统一起使用的）。这是因为 `service` 命令实际上已重定向到 `systemctl`。systemd 引入了向后兼容性，因为系统管理员们习惯使用 `service` 命令。
+>
+> 在本教程中，我将同时展示 `systemctl` 和 `service` 命令。
+
+我用的是 Ubuntu 18.04，但其他版本的过程也一样。
+
+### 方法 1：使用 systemd 在 Linux 中管理服务
+
+我从 systemd 开始，因为它被广泛接受。
+
+#### 1、列出所有服务
+
+为了管理服务，你首先需要知道系统上有哪些服务可用。你可以使用 systemd 的命令列出 Linux 系统上的所有服务：
+
+```
+systemctl list-unit-files --type service -all
+```
+
+![systemctl list-unit-files][3]
+
+此命令将输出所有服务的状态。服务状态有启用、禁用、屏蔽（在取消屏蔽之前处于非活动状态）、静态和已生成。
+
+与 [grep 命令][4] 结合，你可以仅显示正在运行的服务：
+
+```
+sudo systemctl | grep running
+```
+
+![Display running services systemctl][5]
+
+现在，你知道了如何引用所有不同的服务，你可以开始主动管理它们。
+
+**注意：** 下列命令中的 `` 应该用你想管理的服务名代替。（比如：network-manager、ufw 等）
+
+#### 2、启动服务
+
+要在 Linux 中启动服务，你只需使用它的名字：
+
+```
+systemctl start
+```
+
+#### 3、停止服务
+
+要停止 systemd 服务，可以使用 `systemctl` 命令的 `stop` 选项：
+
+```
+systemctl stop
+```
+
+#### 4、重启服务
+
+要重启 systemd 服务，可以使用：
+
+```
+systemctl restart
+```
+
+#### 5、检查服务状态
+
+你可以通过打印服务状态来确认你已经成功执行特定操作：
+
+```
+systemctl status
+```
+
+这将以以下方式输出：
+
+![systemctl status][6]
+
+这是 systemd 的内容。现在切换到 init。
+
+### 方法 2：使用 init 在 Linux 中管理服务
+
+init 的命令和 systemd 的一样简单。
+
+#### 1、列出所有服务
+
+要列出所有 Linux 服务，使用：
+
+```
+service --status-all
+```
+
+![service –status-all][7]
+
+前面的 `[ – ]` 代表**禁用**，`[ + ]` 代表**启用**。
+
+#### 2、启动服务
+
+要在 Ubuntu 和其他发行版中启动服务，使用命令：
+
+```
+service start
+```
+
+#### 3、停止服务
+
+停止服务同样简单。
+
+```
+service stop
+```
+
+#### 4、重启服务
+
+如果你想重启服务，命令是：
+
+```
+service restart
+```
+
+#### 5、检查服务状态
+
+此外，要检查是否达到了预期的结果，你可以输出服务状态：
+
+```
+service status
+```
+
+这将以以下方式输出：
+
+![service status][8]
+
+最重要的是，这将告诉你某项服务是否处于活跃状态（正在运行）。
+
+### 总结
+
+今天，我详细介绍了两种在 Ubuntu 或任何其他 Linux 系统上管理服务的非常简单的方法。 希望本文对你有所帮助。
+
+你更喜欢哪种方法？ 让我在下面的评论中知道！
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/start-stop-restart-services-linux/
+
+作者：[Sergiu][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/sergiu/
+[b]: https://github.com/lujun9972
+[1]: https://itsfoss.com/keyboard-mouse-sharing-between-computers/
+[2]: https://itsfoss.com/set-up-firewall-gufw/
+[3]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/systemctl_list_services.png?ssl=1
+[4]: https://linuxhandbook.com/grep-command-examples/
+[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/systemctl_grep_running.jpg?ssl=1
+[6]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/systemctl_status.jpg?ssl=1
+[7]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/service_status_all.png?ssl=1
+[8]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/service_status.jpg?ssl=1
diff --git a/published/20191221 Customize your Linux desktop with KDE Plasma.md b/published/20191221 Customize your Linux desktop with KDE Plasma.md
new file mode 100644
index 0000000000..23f83f5d41
--- /dev/null
+++ b/published/20191221 Customize your Linux desktop with KDE Plasma.md
@@ -0,0 +1,70 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11728-1.html)
+[#]: subject: (Customize your Linux desktop with KDE Plasma)
+[#]: via: (https://opensource.com/article/19/12/linux-kde-plasma)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+使用 KDE Plasma 定制 Linux 桌面
+======
+
+> 本文是 24 天 Linux 桌面特别系列的一部分。如果你认为没有太多自定义桌面的需要，KDE Plasma 可能适合你。
+
+![5 pengiuns floating on iceburg][1]
+
+KDE 社区的 Plasma 桌面是开源桌面环境中的巅峰之作。KDE 很早就进入了 Linux 桌面环境市场，但是由于它的基础 Qt 工具包当时没有完全开放的许可证，因此才有 [GNOME][2] 桌面。在此之后，Qt 开源了，并且 KDE（及其衍生产品，例如 [Trinity 桌面][3]）开始蓬勃发展。
+
+你可能会在发行版的软件仓库中找到 KDE 桌面，或者可以下载并安装将 KDE 作为默认桌面的发行版。在安装之前，请注意，KDE 提供了完整、集成且强大的桌面体验，因此会同时安装几个 KDE 应用。如果你已经在运行其他桌面，那么将发现有几个冗余的应用（两个 PDF 阅读器、多个媒体播放器、两个或多个文件管理器，等等）。如果你只想尝试而不是一直使用 KDE 桌面，那么可以在虚拟机，如 [GNOME Boxes][4] 中安装基于 KDE 的发行版，也可以尝试使用可引导的操作系统，例如 [Porteus][5]。
+
+### KDE 桌面之旅
+
+乍一看，[KDE Plasma][6] 桌面相对无聊，但让人感到舒适。它有行业标准的布局：左下角弹出应用菜单，中间是任务栏，右边是系统托盘。这正是你对标准家用或商用计算机的期望。
+
+![KDE Plasma desktop][7]
+
+但是，使 KDE 与众不同的是，你几乎可以更改任何想要的东西。Qt 工具包可以以令人惊讶的方式分割和重新排列，这意味着你实质上可以使用 KDE 的部件作为基础来设计自己的桌面。桌面行为的可用设置也很多。KDE 可以充当标准桌面、平铺窗口管理器以及两者之间的任意形式。你可以通过窗口类、角色、类型、标题或它们的任意组合来创建自己的窗口规则，因此，如果希望特定应用的行为不同于其他行为，那么可以创建全局设置的例外。
+
+此外，它还有丰富的小部件集合，使你可以自定义与桌面交互的方式。它有一个类似 GNOME 的全屏应用启动器，一个类似 Unity 的 dock 启动器和仅有图标的任务栏，以及一个传统的任务栏。你可以在屏幕的任何边缘上创建和放置面板。
+
+![A slightly customized KDE desktop][8]
+
+实际上，它有太多的自定义项了，因此 KDE 最常见的批评之一是它的*太过可定制化*，所以请记住，自定义项是可选的。你可以在默认配置下使用 Plasma 桌面，并仅在你认为必要时逐步进行更改。Plasma 桌面配置选项最重要的不是它们的数目，而是它们容易发现和直观，它们都在系统设置应用或者右键单击中。
+
+事实是，在 KDE 上，几乎绝不会只有一种方法可以完成任何给定的任务，并且它的用户将这个视为其最大的优势。KDE 中没有隐含的工作流，只有默认的。并且可以更改所有默认设置，直到你需要桌面做的成为你的习惯。
+
+### 一致性和集成
+
+KDE 社区以一致性和集成为荣，出色的开发人员、社区管理以及 KDE 库使其成为可能。KDE 的开发人员不只是桌面开发人员。它们提供了[惊人的应用集合][9]，每个应用都使用 KDE 库创建，这些库扩展并标准化了常见的 Qt 小部件。使用 KDE 几个月后，无论是打开 [DigiKam][10] 进行照片管理，还是打开 Kmail 来检查电子邮件，还是打开 KTorrent 来获取最新的 ISO 或者使用 Dolphin 管理文件，你的肌肉记忆会在你思考之前直接带你进入对应 UI。
+
+![KDE on Porteus][11]
+
+### 尝试 KDE
+
+KDE 适合所有人。使用其默认设置可获得流畅、原始的桌面体验，或对其进行自定义以使其成为自己专属。它是一个稳定、有吸引力且强大的桌面环境，可能有你想要在 Linux 完成要做的事的一切。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-kde-plasma
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/rh_003499_01_linux31x_cc.png?itok=Pvim4U-B (5 pengiuns floating on iceburg)
+[2]: https://opensource.com/article/19/12/gnome-linux-desktop
+[3]: https://opensource.com/article/19/12/linux-trinity-desktop-environment-tde
+[4]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[5]: https://opensource.com/article/19/6/linux-distros-to-try
+[6]: https://kde.org/plasma-desktop
+[7]: https://opensource.com/sites/default/files/uploads/advent-kde-presskit.jpg (KDE Plasma desktop)
+[8]: https://opensource.com/sites/default/files/uploads/advent-kde-dock.jpg (A slightly customized KDE desktop)
+[9]: https://kde.org/applications/
+[10]: https://opensource.com/life/16/5/how-use-digikam-photo-management
+[11]: https://opensource.com/sites/default/files/uploads/advent-kde.jpg (KDE on Porteus)
diff --git a/published/20191222 How to Update Grub on Ubuntu and Other Linux Distributions.md b/published/20191222 How to Update Grub on Ubuntu and Other Linux Distributions.md
new file mode 100644
index 0000000000..c422b4d808
--- /dev/null
+++ b/published/20191222 How to Update Grub on Ubuntu and Other Linux Distributions.md
@@ -0,0 +1,129 @@
+[#]: collector: (lujun9972)
+[#]: translator: (robsean)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11726-1.html)
+[#]: subject: (How to Update Grub on Ubuntu and Other Linux Distributions)
+[#]: via: (https://itsfoss.com/update-grub/)
+[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
+
+如何在 Ubuntu 和其它 Linux 发行版上更新 grub
+======
+
+
+
+在这篇文章中，你将学习在 Ubuntu 或任何其它 Linux 发行版上更新 grub 。你也将学习一个或两个关于更新这个 grub 过程如何工作的事情。
+
+### 如何更新 grub
+
+Ubuntu 和很多其它的 Linux 发行版提供一个易使用的称为 `update-grub` 命令行实用程序。
+
+为更新 grub ，你所要的全部工作就是使用 `sudo` 在终端中运行这个命令。
+
+```
+sudo update-grub
+```
+
+你应该看到一个像这样的输出：
+
+```
+[email protected]:~$ sudo update-grub
+[sudo] password for abhishek:
+Sourcing file `/etc/default/grub'
+Generating grub configuration file ...
+Found linux image: /boot/vmlinuz-5.0.0-37-generic
+Found initrd image: /boot/initrd.img-5.0.0-37-generic
+Found linux image: /boot/vmlinuz-5.0.0-36-generic
+Found initrd image: /boot/initrd.img-5.0.0-36-generic
+Found linux image: /boot/vmlinuz-5.0.0-31-generic
+Found initrd image: /boot/initrd.img-5.0.0-31-generic
+Found Ubuntu 19.10 (19.10) on /dev/sda4
+Found MX 19 patito feo (19) on /dev/sdb1
+Adding boot menu entry for EFI firmware configuration
+done
+```
+
+你可能看到一个类似的称为 `update-grub2` 的命令。不需要在 `update-grub` 和 `update-grub2` 之间感到害怕或不知所措。这两个命令执行相同的动作。
+
+大约在 10 年前，当 grub2 刚刚被引进时，`update-grub2` 命令也被引进。现在，`update-grub2` 只是一个链接到 `update-grub` 的符号，它们都更新 grub2 配置（因为 grub2 是默认的）。
+
+#### 不能找到 update-grub 命令？这里是在这种情况下该做什么
+
+它可能是，你的 Linux 发行版可能没有可用的 `update-grub` 命令。
+
+在这种情况下你该做什么？你如何在这样一个 Linux 发行版上更新 grub ？
+
+在这里不需要惊慌。`update-grub` 命令只是一个入口，用于运行 `grub-mkconfig -o /boot/grub/grub.cfg` 来生成 grub2 配置文件。
+
+这意味着你可以在任意 Linux 发行版上使用下面的命令更新 grub ：
+
+```
+sudo grub-mkconfig -o /boot/grub/grub.cfg
+```
+
+当然，记住 `update-grub` 命令比上面的命令容易很多，这是为什么它在一开始被创建的原因。
+
+### update-grub 是如何工作的？
+
+当你安装一个 Linux 发行版时，它（通常）要求你安装 [grub 启动引导程序][1]。
+
+grub 的一部分安装在 MBR/ESP 分区上。grub 的剩余部分保留在 Linux 发行版的 `/boot/grub` 目录中。
+
+依据它的 [man 页面][2]，`update-grub` 通过查找 `/boot` 目录来工作。所有以 [vmlinuz-][3] 开头的文件将被作为内核来对待，并且它们将得到一个 grub 菜单项。它也将为与所找到内核版本相同的 [ramdisk][4] 镜像添加 initrd 行。
+
+它也使用 [os-prober][5] 为其它操作系统查找所有磁盘分区。如果找到其它操作系统，它添加它们到 grub 菜单。
+
+![Representational image of Grub Menu][6]
+
+### 为什么你需要更新 grub ？
+
+在有很多场景下你需要更新 grub。
+
+假设你修改 grub 配置文件（`/etc/default/grub`）以 [更改默认启动顺序][7] 或减少默认启动时间。除非你更新 grub ，否则你的修改将不会生效。
+
+另一种情况是，你在同一个电脑系统上安装多个 Linux 发行版。
+
+例如，在我的 Intel NUC 上，我有两个磁盘。第一个磁盘有 Ubuntu 19.10 ，并且我在其上面安装了 Ubuntu 18.04 。第二个操作系统（Ubuntu 18.04）安装了其自己的 grub ，现在 grub 启动屏幕由 Ubuntu 18.04 grub 控制。
+
+在第二个磁盘上，我安装了 MX Linux ，但是这次我没有安装 grub。我希望现有的 grub（由 Ubuntu 18.04 控制）来处理所有的操作系统项目。
+
+现在，在这种情况中，在 Ubuntu 18.04 上的 grub 需要更新，以便它能够看到 [MX Linux][8] 。
+
+![][9]
+
+如上图所示，当我更新 grub 时，它在 18.04 上找到很多安装的 Linux 内核, 以及在不同的分区上 Ubntu 19.10 和 MX Linux 。
+
+如果你想让 MX Linux 控制 grub ，我可以使用 [grub-install][10] 命令来在 MX Linux 上安装 grub，然后在 MX Linux 上的 grub 将开始控制 grub 启动屏幕。你已经明白这点，对吧？
+
+使用一个像 [Grub Customizer][11] 的 GUI 工具是在 grub 中进行更改的一种简单的方法。
+
+### 最后…
+
+最初，我打算保持它为一篇短文作为一种快速提示。但是后来我想解释一些与之相关的东西，以便（相对）新的 Linux 用户能够学到更多，而不仅仅是一个简单命令。
+
+你喜欢它吗？你有一些问题或建议吗？请随意发表评论。
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/update-grub/
+
+作者：[Abhishek Prakash][a]
+选题：[lujun9972][b]
+译者：[robsean](https://github.com/robsean)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/abhishek/
+[b]: https://github.com/lujun9972
+[1]: https://en.wikipedia.org/wiki/GNU_GRUB
+[2]: https://manpages.debian.org/testing/grub-legacy/update-grub.8.en.html
+[3]: https://www.ibm.com/developerworks/community/blogs/mhhaque/entry/anatomy_of_the_initrd_and_vmlinuz?lang=en
+[4]: https://en.wikipedia.org/wiki/Initial_ramdisk
+[5]: https://packages.debian.org/sid/utils/os-prober
+[6]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/grub_screen.png?ssl=1
+[7]: https://itsfoss.com/grub-customizer-ubuntu/
+[8]: https://mxlinux.org/
+[9]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/update_grub.png?ssl=1
+[10]: https://www.gnu.org/software/grub/manual/grub/html_node/Installing-GRUB-using-grub_002dinstall.html
+[11]: https://itsfoss.com/customize-grub-linux/
diff --git a/published/20191222 Why your Python code needs to be beautiful and explicit.md b/published/20191222 Why your Python code needs to be beautiful and explicit.md
new file mode 100644
index 0000000000..4afb58bbb0
--- /dev/null
+++ b/published/20191222 Why your Python code needs to be beautiful and explicit.md
@@ -0,0 +1,69 @@
+[#]: collector: (lujun9972)
+[#]: translator: (HankChow)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11718-1.html)
+[#]: subject: (Why your Python code needs to be beautiful and explicit)
+[#]: via: (https://opensource.com/article/19/12/zen-python-beauty-clarity)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+为什么 Python 代码要写得美观而明确
+======
+
+> 欢迎阅读“Python 光明节（Pythonukkah）”系列文章，这个系列文章将会讨论《Python 之禅》。我们首先来看《Python 之禅》里的前两个原则：美观与明确。
+
+
+
+早在 1999 年，Python 的贡献者之一，Tim Peters 就提出了《[Python 之禅][2]》，直到二十年后的今天，《Python 之禅》中的 19 条原则仍然对整个社区都产生着深远的影响。为此，就像庆典光明的光明节一样，我们举行了这一次的“Python 光明节”。首先，我们会讨论《Python 之禅》中的前两个原则：美观和明确。
+
+> “Hanukkah is the Festival of Lights,
+>
+> Instead of one day of presents, we get eight crazy nights.”
+>
+> —亚当·桑德勒，[光明节之歌][3]
+
+### 美观胜于丑陋
+
+著名的《[计算机程序的构造和解释][4]》中有这么一句话：代码是写给人看的，只是恰好能让机器运行。机器并不在乎代码的美观性，但人类在乎。
+
+阅读美观的代码对人们来说是一种享受，这就要求在整套代码中保持一致的风格。使用诸如 [Black][5]、[flake8][6]、[Pylint][7] 这一类工具能够有效地接近这一个目标。
+
+但实际上，只有人类自己才知道什么才是真正的美观。因此，代码审查和协同开发是其中的不二法门，同时，在开发过程中倾听别人的意见也是必不可少的。
+
+最后，个人的主观能动性也很重要，否则一切工具和流程都会变得毫无意义。只有意识到美观的重要性，才能主动编写出美观的代码。
+
+这就是为什么美观在众多原则当中排到了首位，它让“美”成为了 Python 社区的一种价值。如果有人要问，”我们*真的*在乎美吗？“社区会以代码给出肯定的答案。
+
+### 明确胜于隐晦
+
+人类会欢庆光明、惧怕黑暗，那是因为光能够让我们看到难以看清的事物。同样地，尽管有些时候我们会不自觉地把代码写得含糊不清，但明确地编写代码确实能够让我们理解很多抽象的概念。
+
+“为什么类方法中要将 `self` 显式指定为第一个参数？”
+
+这个问题已经是老生常谈了，但网络上很多流传已久的回答都是不准确的。在编写元类时，显式指定 `self` 参数就显得毫无意义。如果你没有编写过元类，希望你可以尝试一下，这是很多 Python 程序员的必经之路。
+
+显式指定 `self` 参数的原因并不是 Python 的设计者不想将这样的元类视为“默认”元类，而是因为第一个参数必须是*显式*的。
+
+即使 Python 中确实允许非显式的情况存在（例如上下文变量），但我们还是应该提出疑问：某个东西是不是有存在的必要呢？如果非显式地传递参数会不会出现问题呢？有些时候，由于种种原因，这是会有问题的。总之，在写代码时一旦能够优先考虑到明确性，至少意味着能对不明确的地方提出疑问并对结果作出有效的估计。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/zen-python-beauty-clarity
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[HankChow](https://github.com/HankChow)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/search_find_code_python_programming.png?itok=ynSL8XRV "Searching for code"
+[2]: https://www.python.org/dev/peps/pep-0020/
+[3]: https://en.wikipedia.org/wiki/The_Chanukah_Song
+[4]: https://en.wikipedia.org/wiki/Structure_and_Interpretation_of_Computer_Programs
+[5]: https://opensource.com/article/19/5/python-black
+[6]: https://opensource.com/article/19/5/python-flake8
+[7]: https://opensource.com/article/19/10/python-pylint-introduction
+
diff --git a/published/20191224 Unix is turning 50. What does that mean.md b/published/20191224 Unix is turning 50. What does that mean.md
new file mode 100644
index 0000000000..948adc58bf
--- /dev/null
+++ b/published/20191224 Unix is turning 50. What does that mean.md
@@ -0,0 +1,116 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: (wxy)
+[#]: publisher: (wxy)
+[#]: url: (https://linux.cn/article-11724-1.html)
+[#]: subject: (Unix is turning 50. What does that mean?)
+[#]: via: (https://www.networkworld.com/article/3511428/unix-is-turning-50-what-does-that-mean.html)
+[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
+
+Unix 即将迎来 50 岁
+======
+
+Unix 时间（又称为“纪元时间”）是自 1970 年 1 月 1 日以来经过的秒数。当 Unix 即将 50 岁时，让我们看一下让内核开发人员担心的地方。
+
+
+
+对于 Unix 而言，2020 年是重要的一年。在这一年年初，Unix 进入 50 岁。
+
+尽管 Unix 的某些早期开发早于其“纪元”的正式开始，但 1970 年 1 月 1 日仍然是 POSIX 时间的零点，也是公认的 Unix 的万物之始。自那一刻算起，2020 年 1 月 1 日将是其 50 周年。（LCTT 译注：实际上，在 1971/11/3 出版的第一版《Unix 程序员手册》中，将 1971/1/1 作为 Unix 纪元的开始，并且一秒钟记录 60 个数，但是后来发现这样 32 位整型数字只能记录两年多，后来这个纪元被一再重新定义，改为从 1970/1/1 开始，每秒 1 个数。）
+
+### Unix 时间与人类时间
+
+就人类时间而言，50 年是很重要的。就 Unix 时间而言，50 年没有什么特别的。48.7 年同样重要。
+
+Unix（包括 Linux）系统将日期/时间值存储为自 1970-01-01 00:00:00 UTC 以来经过的秒数（32 位整型）。要确定自该时间以来经过了多少秒钟，看看 Unix 时间值是什么样子，你可以发出如下命令：
+
+```
+$ date +%s
+1576883876
+```
+
+`％s` 参数告诉 `date` 命令将当前日期/时间显示为自 1970-01-01 开始以来的秒数。
+
+### Unix 系统可以管理多少时间？
+
+要了解 Unix 系统可以容纳多少时间，我们需要查看 32 位字段的容量。可以这样计算：
+
+```
+$ echo '2^32' | bc
+4294967296
+```
+
+但是，由于 Unix 需要容纳负数，因此它会为数字的符号保留一位，从而将其减少为：
+
+```
+$ echo '2^31' | bc
+2147483648
+```
+
+并且，由于 Unix 计数以 0 开头，这意味着我们有 2,147,483,648 个值，但最大的可能值为 2,147,483,647 个。Unix 日期/时间值不能超过该数字——就像汽车上的里程表可能不能超过 999,999 英里一样。加 1 该值就变为了 -2147483648。（LCTT 译注：此处原文描述有误，已修改。在达到最大值之后，即 2038/1/19 03:14:07，下 1 秒导致符号位变为 1，其余 31 位为 0，即 -2147483648，时间变为 1901/12/13 20:45:52，这就是 Y2K38 问题。）
+
+### 一年有多少秒？
+
+大多数年份的秒数可以这样计算：每天的小时数乘以每小时的分钟数乘以每分钟的秒数乘以一年中的天数：
+
+```
+$ expr 24 \* 60 \* 60 \* 365
+31536000
+```
+
+在闰年，我们再增加一天：
+
+```
+$ expr 24 \* 60 \* 60 \* 366
+31622400
+```
+
+（LCTT 译注：Unix 时间将一天精确定义为 24 * 60 * 60 = 86400 秒，忽略闰秒。）
+
+### Unix 将如何庆祝其 50 岁生日？
+
+2020 年 1 月 1 日中午 12:00 是纪元时间的 1577836800。这个计算有些棘手，但主要是因为我们必须适应闰年。自该纪元开始以来，我们经历了 12 个闰年，从 1972 年开始，到上一个闰年是 2016 年。而且，当我们达到 2020 年时，我们将有 38 个常规年份。
+
+这是使用 `expr` 命令进行的计算，以计算这 50 年的秒数：
+
+```
+$ expr 24 \* 60 \* 60 \* 365 \* 38 + 24 \* 60 \* 60 \* 366 \* 12
+1577836800
+```
+
+前半部分是计算 38 个非闰年的秒数。然后，我们加上闰年的 366 天的类似计算。或者，你可以使用前面介绍的每年秒数，然后执行以下操作：
+
+```
+$ expr 31536000 \* 38 + 31622400 \* 12
+1577836800
+```
+
+这种跟踪日期和时间的方式使 Unix 系统完全不受 Y2K 恐慌的影响，1999 年末人们开始担心进入 2000 年会对计算机系统造成严重破坏，但是实际遇到的问题比人们担心的少得多。实际上，只有以两位数格式存储年份的应用程序才会将年份变为 00，以表示时间倒退。尽管如此，许多应用程序开发人员还是做了很多额外的繁琐工作，以确保 2000 年到来时，他们的系统不会出现严重问题。
+
+### Unix 时间何时会遇到问题？
+
+在 2038 年之前，Unix 系统不会遇到 Y2K 类型的问题，直到如上所述存储的日期将超过其 32 位空间分配。但这距离现在已经只有 18 年了，内核开发人员已经在研究如何避免灾难。但现在开始恐慌还为时过早。
+
+2038 年的问题有时称为 Y2K38 问题。我们必须在 2038 年 1 月 19 日星期二之前解决这个问题。如果问题到时候仍未解决，则该日期之后的系统可能会认为是 1901 年。解决该问题的一种方法是切换为日期/时间信息的 64 位表示形式。有些人认为，即使那样，也会有比听起来更复杂的问题。无论如何，恐慌还为时过早。并且，与此同时，也许在新年前夜演唱了《Auld Lang Syne》之后，你可以向 Unix 唱《生日快乐》歌了。Unix 50 岁了，这仍然是大事。
+
+（LCTT 译注：建议阅读一下 Unix 时间的[维基百科][6]页面，有更多有趣和不为人知的信息。）
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3511428/unix-is-turning-50-what-does-that-mean.html
+
+作者：[Sandra Henry-Stocker][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[wxy](https://github.com/wxy)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
+[b]: https://github.com/lujun9972
+[1]: https://images.idgesg.net/images/article/2017/10/birthday-cake-candles-100739452-large.jpg
+[2]: https://creativecommons.org/publicdomain/zero/1.0/
+[3]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[4]: https://www.facebook.com/NetworkWorld/
+[5]: https://www.linkedin.com/company/network-world
+[6]: https://en.wikipedia.org/wiki/Unix_time
diff --git a/sources/news/20191127 Zorin OS Responds to the Privacy Concerns.md b/sources/news/20191127 Zorin OS Responds to the Privacy Concerns.md
deleted file mode 100644
index 51151d2e87..0000000000
--- a/sources/news/20191127 Zorin OS Responds to the Privacy Concerns.md
+++ /dev/null
@@ -1,105 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Zorin OS Responds to the Privacy Concerns)
-[#]: via: (https://itsfoss.com/zorin-os-privacy-concerns/)
-[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
-
-Zorin OS Responds to the Privacy Concerns
-======
-
-_**There were some privacy concerns around ‘data collection’ in Zorin OS. It’s FOSS spoke to Zorin OS CEO and here is his response to the controversy.**_
-
-After a few days of [Zorin OS 15 Lite][1] release, a Reddit thread surfaced which flagged a privacy concern regarding the Linux distribution.
-
-The [Reddit thread][2] focuses on the [privacy policy][3] of Zorin OS and warns users that Zorin OS is sending anonymous pings every 60 minutes without users’ consent, which is potentially a privacy issue.
-
-![][4]
-
-The policy in question can be quoted here as:
-
-> _**Anonymous pings**: When using Zorin OS, your computer may occasionally send us a ping which includes an anonymous unique identifier for your computer. We use this information to count the number of active users of Zorin OS. The unique identifier does not identify you unless you (or someone acting on your behalf) discloses it separately. You may choose to disable these pings by uninstalling the “Zorin-os-census” package from your computer_
-
-Now, there’s a lot of [discussions][5] surrounding the concern. There’s also a [YouTube video][6] talking about it.
-
-In a nutshell, it’s a mess. Some insist that they collect our IP addresses and some users complain that they should ask about it while installing Zorin OS.
-
-While I agree that they could add an opt-out option in the installation process – so I reached out to **Artyom Zorin** (_CEO, Zorin Group_) to clarify the situation.
-
-### Zorin’s Clarification On What They Collect With Every Anonymous Ping
-
-When I asked for an elaborate explanation of what the “**anonymous unique identifier**” includes, Artyom mentioned – “_It appears that there are some inaccuracies and misconceptions about the census in the comments sections_“.
-
-To continue the explanation about the unique identifier, he assured that **their servers do not log IP addresses** when a ping arrives.
-
-The zorin-os-census script **simply counts the number of unique computers using Zorin OS** and no personal data is being collected along with it.
-
-Artyom explained in detail:
-
-> The anonymous identifier is a series of letters and numbers which is randomly generated (not based on any external data) and only used for the Zorin OS Census. Its single purpose is to make sure that the computer isn’t double-counted when a ping is sent from a computer to the server. On a fully-installed Zorin OS system, the anonymous identifier can be found in /var/lib/zorin-os-census/uuid and should look like this:_68f2d95b-f51f-4a5d-9b48-a99c28691b89_
-> *
-> *We would like to clarify that no personal or personally-identifiable data is being collected by us and the server does not log IP addresses when pings arrive. The zorin-os-census script is only used to count the number of computers and users running Zorin OS after installation. Even I wouldn’t be able to tell which computer is my own from looking at the server-side database. I have attached a screenshot of a snippet of the database table displaying the information we store.
-
-He also stressed his ‘commitment on privacy’:
-
-> Privacy is an essential human right. It’s a core tenet of our mission to give you back control of your technology, and not the other way around. We make privacy a priority with every decision we make, and we’re committed to protecting it in every level of the software we build.
-
-As you can observe in the response above, he shared a screenshot of how their database of unique identifiers looks like:
-
-![][7]
-
-If you’re still curious, you can also check out the [source code][8] for the zorin-os-census script.
-
-### Can We Opt-Out Of It?
-
-While the data collected may be ‘harmless’, it is important to give the option to the user whether or not they want Zorin OS to collect the data, right?
-
-So, when I inquired about the same, he mentioned that i**t was already something planned for Zorin OS 15 Lite release**.
-
-However, they did not want to rush to add it before properly testing it. Hence, they decided to keep it for the upcoming release (**Zorin OS 15.1**) which is planned to arrive in **early-to-mid December this year.**
-
-> We have in fact been working on implementing an opt-out option for this into the Zorin OS installer (Ubiquity). To ensure the stability and accessibility of this new functionality we’re adding to Ubiquity, we have scheduled a period of time to translate the text strings and rigorously test the software (in order to avoid regressions), as the installer is a critical component of the operating system. Unfortunately, the testing period for the opt-out option didn’t complete before our planned release of Zorin OS 15 Lite, and we, therefore, decided not to risk adding it before we could guarantee its stability. However, we are on track to include the opt-out option in the upcoming Zorin OS 15.1 release, which we plan to release in early-to-mid December.
-
-### Will It Be Something Similar To What Ubuntu Does?
-
-Ubuntu does let you opt-out from collecting information about your computer.
-
-So, when I asked if Zorin OS will add something similar to that, he responded with some details about how Ubuntu collects data and how Zorin OS is different from that.
-
-He mentioned the fact that Ubuntu comes pre-installed with a **popularity-contest** package that **occasionally sends data of what packages the user has installed** to the Ubuntu Developers.
-
-And, further clarified that **Zorin OS does not include that**.
-
-> While Ubuntu’s telemetry tool gives users the option to not send extensive information about the computers to the Ubuntu developers, selecting the “No” option still sends a ping to Ubuntu’s servers .
->
-> From our research, it is not clear whether Ubuntu’s servers store logs of users’ IP addresses when they receive telemetry data. In addition, Zorin OS does not include the “popularity-contest” package that is pre-installed in Ubuntu. This package is designed to occasionally send a list of all packages a user has installed on their computer to the Ubuntu developers.
-
-**In the end…**
-
-While the concern regarding the anonymous pings may not seem to a privacy threat, an opt-out option should be presented to the user while installing Zorin OS. Let’s wait and watch if it should arrive in the upcoming Zorin OS 15.1 release.
-
-What do you think about the privacy concern mentioned above? Let us know your thoughts in the comments down below.
-
---------------------------------------------------------------------------------
-
-via: https://itsfoss.com/zorin-os-privacy-concerns/
-
-作者：[Ankush Das][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://itsfoss.com/author/ankush/
-[b]: https://github.com/lujun9972
-[1]: https://itsfoss.com/zorin-os-lite/
-[2]: https://www.reddit.com/r/FreeAsInFreedom/comments/e0yhw4/beware_zorin_os_sends_anonymous_pings_every_60/
-[3]: https://zorinos.com/legal/privacy/
-[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/zorin-os-privacy-reddit.jpg?ssl=1
-[5]: https://www.reddit.com/r/linux/comments/e0zd5n/beware_zorin_os_sends_anonymous_pings_every_60/
-[6]: https://www.youtube.com/watch?v=bcgk9LvC36Y&feature=youtu.be&t=860
-[7]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/11/zorin-census-database.png?ssl=1
-[8]: https://launchpad.net/~zorinos/+archive/ubuntu/stable/+sourcepub/10183568/+listing-archive-extra
diff --git a/sources/news/20191128 Open Source Music Notations Software MuseScore 3.3 Released.md b/sources/news/20191128 Open Source Music Notations Software MuseScore 3.3 Released.md
deleted file mode 100644
index 2835a5d06a..0000000000
--- a/sources/news/20191128 Open Source Music Notations Software MuseScore 3.3 Released.md
+++ /dev/null
@@ -1,89 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Open Source Music Notations Software MuseScore 3.3 Released!)
-[#]: via: (https://itsfoss.com/musescore/)
-[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
-
-Open Source Music Notations Software MuseScore 3.3 Released!
-======
-
-_**Brief: MuseScore is an open-source software to help you create, play, and print sheet music. They released a major update recently. So, we take a look at what MuseScore has to offer**_ _**overall.**_
-
-### MuseScore: A Music Composition and Notation Software
-
-![][1]
-
-[MuseScore][2] is open-source software that lets you create, play, and print [sheet music][3].
-
-You can even use a MIDI keyboard as input and simply play the tune you want to create the notation of.
-
-In order to make use of it, you need to know how sheet music notations work. In either case, you can just play something using your MIDI keyboard or any other instrument and learn how the music notations work while using it.
-
-So, it should come in handy for beginners and experts as well.
-
-You can download and use MuseScore for free. However, if you want to share your music/composition and reach out to a wider community on the MuseScore platform, you can opt to create a free or premium account on [MuseScore.com][4].
-
-### Features of MuseScore
-
-![Musescore 3 Screenshot][5]
-
-MuseScore includes a lot of things that can be highlighted. If you are someone who is not involved in making music notations for your compositions – you might have to dig deeper just like me.
-
-Usually, I just head over to any [DAW available on Linux][6] and start playing something to record/loop it without needing to create the music notations. So, for me, MuseScore definitely presents a learning curve with all the features offered.
-
-I’ll just list out the features with some brief descriptions – so you can explore them if it sounds interesting to you.
-
- * Supports Input via MIDI keyboard
- * You can transfer to/from other programs via [MusicXML][7], MIDI, and other options.
- * A Huge collection of palettes (music symbols) to choose from.
- * You also get the ability to re-arrange the palettes and create your own list of most-used palettes or edit them.
- * Some plugins supported to extend the functionality
- * Import PDFs to read and play notations
- * Several instruments supported
- * Basic or Advanced layout of palettes to get started
-
-
-
-Some of the recent key changes include the palettes redesign, accessibility, and the not input workflow. For reference, you can check out how the new palettes work:
-
-### Installing MuseScore 3.3.3 on Ubuntu/Linux
-
-The latest version of MuseScore is 3.3.3 with all the bug fixes and improvements to its recent [MuseScore 3.3 release][8].
-
-You may find an older release in your Software Center (or your official repo). So, you can either opt for a Flatpak package, Snap, or maybe an AppImage from its [download page][9] with links for different Linux distributions.
-
-[Download MuseScore][9]
-
-**Wrapping Up**
-
-I was quite fascinated to learn about MuseScore being an open-source and free solution to create, play, and print sheet music.
-
-It may not be the most easy-to-use software there is – but when considering the work with music notations, it will help you learn more about it and help you with your work as well.
-
-What do you think about MuseScore? Do share your thoughts in the comments below.
-
---------------------------------------------------------------------------------
-
-via: https://itsfoss.com/musescore/
-
-作者：[Ankush Das][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://itsfoss.com/author/ankush/
-[b]: https://github.com/lujun9972
-[1]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/musescore-3.jpg?ssl=1
-[2]: https://musescore.org/en
-[3]: https://en.wikipedia.org/wiki/Sheet_music
-[4]: https://musescore.com/
-[5]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/11/musescore-3-screenshot.jpg?ssl=1
-[6]: https://itsfoss.com/best-audio-editors-linux/
-[7]: https://en.wikipedia.org/wiki/MusicXML
-[8]: https://musescore.org/en/3.3
-[9]: https://musescore.org/en/download
diff --git a/sources/news/20191207 New machine learning from Alibaba and Netflix, mimicking animal vision, and more open source news.md b/sources/news/20191207 New machine learning from Alibaba and Netflix, mimicking animal vision, and more open source news.md
new file mode 100644
index 0000000000..93297c4cad
--- /dev/null
+++ b/sources/news/20191207 New machine learning from Alibaba and Netflix, mimicking animal vision, and more open source news.md
@@ -0,0 +1,93 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (New machine learning from Alibaba and Netflix, mimicking animal vision, and more open source news)
+[#]: via: (https://opensource.com/article/19/12/news-december-7)
+[#]: author: (Scott Nesbitt https://opensource.com/users/scottnesbitt)
+
+New machine learning from Alibaba and Netflix, mimicking animal vision, and more open source news
+======
+Catch up on the biggest open source headlines from the past two weeks.
+![Weekly news roundup with TV][1]
+
+In this edition of our open source news roundup, we take a look an open source election auditing tool, new open source from Alibaba and Netflix, mimicking animal vision, and more!
+
+### Alibaba and Netflix share machine learning and data science software
+
+Two companies at the forefront of machine learning and data science have just released some of their tools under open source licenses.
+
+Chinese ecommerce giant Alibaba just [open sourced the algorithm libraries][2] for its Alink platform. The algorithms "are essential to support machine learning tasks such as online product recommendations and smart customer services." According to Jia Yangqing, president of Alibaba Cloud, Alink is a good fit for "developers seeking big data and machine-learning tools." You can find the source code for Alink (which is under an Apache 2.0 license) [on GitHub][3], with documentation in both Chinese and English.
+
+Not to be outdone, streaming service Netflix just released its [Metaflow Python library][4] under an Apache 2.0 license. Metaflow enables data scientists to "see early on whether a prototyped model would fail in production, allowing them to fix whatever the issue was". It also works with a number of Python data science libraries, like SciKit Learn, Pytorch, and Tensorflow. You can grab Metaflow's code from [its GitHub repository][5] or learn more about it at the [Metaflow website][6].
+
+### Open source software to mimic animal vision
+
+Have you ever wondered how your dog or cat sees the world? Thanks to work by researchers at the University of Exeter in the UK and Australia's University of Queensland, you can find out. The team just released [software that allows humans to see the world as animals do][7].
+
+Called micaToolbox, the software can interpret digital photos and process images of various environments by mimicking the limitations of animal vision. Anyone with a camera, a computer, or smartphone can use the software without knowing how to code. But micaToolbox isn't just a novelty. It's a serious scientific tool that can help "help biologists better understand a variety of animal behaviors, including mating systems, distance-dependent signalling and mimicry." And, according to researcher Jolyon Troscianko, the software can help identify "how an animal's camouflage works so that we can manage our land to protect certain species."
+
+You can [download micaBox][8] or [browse its source code][9] on GitHub.
+
+### New tool for post-election auditing
+
+More and more aspects of our lives and institutions are being automated. With that comes an increased danger of systems breaking down or malicious someones tampering with those systems. Open source gives us an opportunity to look at exactly how the automation works.
+
+Elections, in particular, are increasingly vulnerable. To combat election tampering, the US Cybersecurity and Infrastructure Security Agency (CISA) has joined forces with the non-profit organization VotingWorks to create a [web-based application for auditing ballots][10].
+
+Called Arlo, the application is designed to ensure that "elections are secure, resilient, and transparent," said CISA's director Chris Krebs. Arlo works with a range of automated voting systems to help "officials compare audited votes to tabulated votes, and providing monitoring & reporting capabilities." Arlo was used to verify the results of recent state and local elections and is being further field-tested in the states of Georgia, Michigan, Missouri, Ohio, Pennsylvania, and Virginia.
+
+Arlo's source code, released under an AGPL-3.0 license, is [available on GitHub][11].
+
+### Royal Navy debuts open source application development kit
+
+Consistency across user interfaces is key to a successful set of applications and services. The UK's Royal Navy understands the importance of this and has released the [open source NELSON standards toolkit][12] to help its developers and suppliers "save time and give users a consistent experience."
+
+Named after the legendary British admiral, NELSON is intended to "maintain high visual consistency and user-experience quality across the different applications developed or subcontracted by the Royal Navy." The toolkit consists of a set of components including visual styles, typographic elements, forms, elements like buttons and checkboxes, and notifications.
+
+NELSON has its own [GitHub repository][13], from which the Royal Navy encourages developers to make pull requests.
+
+#### In other news
+
+ * [Council group plans for open source revenues and benefits platform][14]
+ * [Introducing Nebula, the open source global overlay network from Slack][15]
+ * [webOS Open Source Edition 2.0 keeps Palm's spirit alive in cars and IoT][16]
+ * [Duke University Introduces an Open Source Tool as an Alternative to a Monolithic LMS][17]
+ * [Open Source Technology Could Be a Boon to Farmers][18]
+
+
+
+_Thanks, as always, to Opensource.com staff members and moderators for their help this week._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/news-december-7
+
+作者：[Scott Nesbitt][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/scottnesbitt
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/weekly_news_roundup_tv.png?itok=B6PM4S1i (Weekly news roundup with TV)
+[2]: https://www.zdnet.com/article/alibaba-cloud-publishes-machine-learning-algorithm-on-github/
+[3]: https://github.com/alibaba/alink
+[4]: https://www.zdnet.com/article/netflix-our-metaflow-python-library-for-faster-data-science-is-now-open-source/
+[5]: https://github.com/Netflix/metaflow
+[6]: https://metaflow.org/
+[7]: https://www.upi.com/Science_News/2019/12/03/Novel-software-helps-scientists-see-what-animals-see/5961575389734/
+[8]: http://www.empiricalimaging.com/download/micatoolbox/
+[9]: https://github.com/troscianko/micaToolbox
+[10]: https://www.zdnet.com/article/cisa-and-votingworks-release-open-source-post-election-auditing-tool/
+[11]: https://github.com/votingworks/arlo
+[12]: https://joinup.ec.europa.eu/collection/open-source-observatory-osor/news/open-source-royal-navy
+[13]: https://github.com/Royal-Navy/standards-toolkit
+[14]: https://www.ukauthority.com/articles/council-group-plans-for-open-source-revenues-and-benefits/
+[15]: https://slack.engineering/introducing-nebula-the-open-source-global-overlay-network-from-slack-884110a5579
+[16]: https://www.slashgear.com/webos-open-source-edition-2-0-keeps-palms-spirit-alive-in-cars-and-iot-25601309/
+[17]: https://iblnews.org/duke-university-introduces-an-open-source-tool-as-an-alternative-to-a-monolithic-lms/
+[18]: https://civileats.com/2019/12/02/open-source-technology-could-be-a-boon-to-farmers/
diff --git a/sources/news/20191209 First Ever Release of Ubuntu Cinnamon Distribution is Finally Here.md b/sources/news/20191209 First Ever Release of Ubuntu Cinnamon Distribution is Finally Here.md
new file mode 100644
index 0000000000..09af65568d
--- /dev/null
+++ b/sources/news/20191209 First Ever Release of Ubuntu Cinnamon Distribution is Finally Here.md
@@ -0,0 +1,85 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (First Ever Release of Ubuntu Cinnamon Distribution is Finally Here!)
+[#]: via: (https://itsfoss.com/ubuntu-cinnamon/)
+[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
+
+First Ever Release of Ubuntu Cinnamon Distribution is Finally Here!
+======
+
+_**Brief: Ubuntu Cinnamon is a new distribution that utilizes Linux Mint’s Cinnamon desktop environment on top of Ubuntu code base. It’s first stable release is based on Ubuntu 19.10 Eoan Ermine.**_
+
+[Cinnamon][1] is Linux Mint’s flagship desktop environment. Like [MATE desktop][2], Cinnamon is also a product of dissatisfaction with GNOME 3. With the GNOME Classic like user interface and relatively lower hardware requirements, Cinnamon soon gathered a dedicated userbase.
+
+Like any other desktop environment out there, you can [install Cinnamon on Ubuntu][3] and other distributions.
+
+Installing multiple [desktop environments][4] (DE) is not a difficult task but it often leads to conflicts (with other DE’s elements) and may not always provide the best experience. This is why major Linux distributions separate spins/flavors with various popular desktop environments.
+
+[Ubuntu also has various official flavors][5] featuring [KDE][6] (Kubuntu), [LXQt][7] (Lubuntu), Xfce (Xubuntu), Budgie ([Ubuntu Budgie][8]) etc. Cinnamon was not in this list but Ubuntu Cinnamon Remix project is trying to change that.
+
+### Ubuntu Cinnamon distribution
+
+![Ubuntu Cinnamon Desktop Screenshot][9]
+
+[Ubuntu Cinnamon][10] (website under construction) is a new Linux distribution that brings Cinnamon desktop to Ubuntu distribution. Joshua Peisach is the lead developer for the project and he is being helped by other volunteer contributors. The ex-developer of the now discontinued Ubuntu GNOME project and some members from Ubuntu team are also advising the team to help with the development.
+
+![Ubuntu Cinnamon Remix Screeenshot 1][11]
+
+Do note that Ubuntu Cinnamon is not an official flavor of Ubuntu. They are trying to get the flavorship but I think that will take a few more releases.
+
+The first stable release of Ubuntu Cinnamon is based on [Ubuntu 19.10 Eoan Ermine][12]. It uses Calamares installer from Lubuntu and features Cinnamon desktop version 4.0.10. Naturally, it uses Nemo file manager and LightDM.
+
+It supports EFI and UEFI and only comes with 64-bit support.
+
+You’ll get your regular goodies like LibreOffice, Firefox and some GNOME software and games. You can of course install more applications as per your need.
+
+### Download and install Ubuntu Cinnamon
+
+Do note that this is the first ever release of Ubuntu Cinnamon and the developers are not that experienced at this moment.
+
+If you don’t like troubleshooting, don’t use it on your main system. I expect this release to have a few bugs and issues which will be fixed eventually as more users test it out.
+
+You can download Ubuntu Cinnamon ISO from Sourceforge website:
+
+[Download Ubuntu Cinnamon][13]
+
+### What next from here?
+
+The dev team has a few improvements planned for the 20.04 release. The changes are mostly on the cosmetics though. There will be new GRUB and Plymouth theme, layout application and welcome screen.
+
+I downloaded it and tried it in a live session. Here’s what this distribution looks like:
+
+[Subscribe to our YouTube channel for more Linux videos][14]
+
+Meanwhile, if you manage to try it on your own, why not share your experience in the comments? If you use Linux Mint, will you switch to Ubuntu Cinnamon in near future? What are your overall opinion about this new project? Do share it in the comment section.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/ubuntu-cinnamon/
+
+作者：[Abhishek Prakash][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/abhishek/
+[b]: https://github.com/lujun9972
+[1]: https://en.wikipedia.org/wiki/Cinnamon_(desktop_environment)
+[2]: https://mate-desktop.org/
+[3]: https://itsfoss.com/install-cinnamon-on-ubuntu/
+[4]: https://itsfoss.com/best-linux-desktop-environments/
+[5]: https://itsfoss.com/which-ubuntu-install/
+[6]: https://kde.org/
+[7]: https://lxqt.org/
+[8]: https://itsfoss.com/ubuntu-budgie-18-review/
+[9]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/ubuntu_cinnamon_distribution_screenshot.jpg?ssl=1
+[10]: https://ubuntucinnamon.org/
+[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/ubuntu_cinnamon_remix_screeenshot_1.jpg?ssl=1
+[12]: https://itsfoss.com/ubuntu-19-10-released/
+[13]: https://sourceforge.net/projects/ubuntu-cinnamon-remix/
+[14]: https://www.youtube.com/c/itsfoss?sub_confirmation=1
diff --git a/sources/news/20191209 KubeCon gets bigger, the kernel gets better, and more industry trends.md b/sources/news/20191209 KubeCon gets bigger, the kernel gets better, and more industry trends.md
new file mode 100644
index 0000000000..81b00a0ec9
--- /dev/null
+++ b/sources/news/20191209 KubeCon gets bigger, the kernel gets better, and more industry trends.md
@@ -0,0 +1,65 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (KubeCon gets bigger, the kernel gets better, and more industry trends)
+[#]: via: (https://opensource.com/article/19/12/kubecon-bigger-kernel-better-more-industry-trends)
+[#]: author: (Tim Hildred https://opensource.com/users/thildred)
+
+KubeCon gets bigger, the kernel gets better, and more industry trends
+======
+A weekly look at open source community, market, and industry trends.
+![Person standing in front of a giant computer screen with numbers, data][1]
+
+As part of my role as a senior product marketing manager at an enterprise software company with an open source development model, I publish a regular update about open source community, market, and industry trends for product marketers, managers, and other influencers. Here are five of my and their favorite articles from that update.
+
+## [KubeCon showed Kubernetes is big, but is it a Unicorn?][2]
+
+> It’s hard to remember now but there was a time when Kubernetes was a distant No. 3 in terms of container orchestrators being used in the market. It’s also eye opening to now realize that [the firms][3] that hatched the two platforms that [towered over][4] Kubernetes have had to completely re-jigger their business models under the Kubernetes onslaught.
+>
+> And full credit to the CNCF for attempting to diffuse some of that attention from Kubernetes by spending the vast majority of the KubeCon opening keynote address touting some of the nearly two dozen graduated, incubating, and sandbox projects it also hosts. But, it was really the Big K that stole the show.
+
+**The impact:** Open source is way more than the source code; governance is a big deal and can be the difference between longevity and irrelevance. Gathering, organizing, and maintaining humans is an entirely different skill set than doing the same for bits, but can have just as big an influence on the success of a project.
+
+## [Report: Kubernetes use on the rise][5]
+
+> At the same time, the Datadog report notes that container churn rates are approximately 10 times higher in orchestrated environments. Churn rates in container environments that lack an orchestration platform such as Kubernetes have increased in the last year as well. The average container lifespan at a typical company running infrastructure without orchestration is about two days, down from about six days in mid-2018. In 19% of those environments not running orchestration, the average container lifetime exceeded 30 days. That compares to only 3% of organizations running containers longer than 30 days in Kubernetes environments, according to the report’s findings.
+
+**The impact**: If your containers aren't churning, you're probably not getting the full benefit of the technology you've adopted.
+
+## [Upcoming Linux 5.5 kernel improves live patching, scheduling][6]
+
+> A new WFX Wi-Fi driver for the Silicon Labs WF200 ASIC transceiver is coming to Linux kernel 5.5. This particular wireless transceiver is geared toward low-power IoT devices and uses a 2.4 GHz 802.11b/g/n radio optimized for low power RF performance in crowded RF environments. This new driver can interface via both Serial Peripheral Interface (SPI) and Secure Digital Input Output (SDIO).
+
+**The impact**: The kernel's continued relevance is a direct result of the never-ending grind to keep being where people need it to be (i.e. basically everywhere).
+
+## [DigitalOcean Currents: December 2019][7]
+
+> In that spirit, this fall’s installment of our seasonal Currents report is dedicated to open source for the second year running. We surveyed more than 5800 developers around the world on the overall health and direction of the open source community. When we last checked in with the community in [2018][8], more than half of developers reported contributing to open source projects, and most felt the community was healthy and growing.
+
+**The impact**: While the good news outweighs the bad, there are a couple of things to keep an eye on: namely, making open source more inclusive and mitigating potential negative impact of big money.
+
+_I hope you enjoyed this list of what stood out to me from last week and come back next Monday for more open source community, market, and industry trends._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/kubecon-bigger-kernel-better-more-industry-trends
+
+作者：[Tim Hildred][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/thildred
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/data_metrics_analytics_desktop_laptop.png?itok=9QXd7AUr (Person standing in front of a giant computer screen with numbers, data)
+[2]: https://www.sdxcentral.com/articles/opinion-editorial/kubecon-showed-kubernetes-is-big-but-is-it-a-unicorn/2019/11/
+[3]: https://www.sdxcentral.com/articles/news/docker-unloads-enterprise-biz-to-mirantis/2019/11/
+[4]: https://www.sdxcentral.com/articles/news/mesosphere-is-now-d2iq-and-kubernetes-is-its-game/2019/08/
+[5]: https://containerjournal.com/topics/container-ecosystems/report-kubernetes-use-on-the-rise/
+[6]: https://thenewstack.io/upcoming-linux-5-5-kernel-improves-live-patching-scheduling/
+[7]: https://blog.digitalocean.com/digitalocean-currents-december-2019/
+[8]: https://www.digitalocean.com/currents/october-2018/
diff --git a/sources/news/20191214 Annual release cycle for Python, new Python Software Foundation fellows from Africa, and more updates.md b/sources/news/20191214 Annual release cycle for Python, new Python Software Foundation fellows from Africa, and more updates.md
new file mode 100644
index 0000000000..85aef63325
--- /dev/null
+++ b/sources/news/20191214 Annual release cycle for Python, new Python Software Foundation fellows from Africa, and more updates.md
@@ -0,0 +1,75 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Annual release cycle for Python, new Python Software Foundation fellows from Africa, and more updates)
+[#]: via: (https://opensource.com/article/19/12/python-news-december)
+[#]: author: (Christian Heimes https://opensource.com/users/christian-heimes)
+
+Annual release cycle for Python, new Python Software Foundation fellows from Africa, and more updates
+======
+Find out what's going on in the Python community in December.
+![Python in a coffee cup.][1]
+
+The Python Software Foundation (PSF) is a nonprofit organization behind the Python programming language. I am fortunate to be a PSF Fellow (honorable member for life,) a Python core developer, and the liaison between my company, Red Hat, and the PSF. Part of that liaison work is providing updates on what’s happening in the Python community. Here’s a look at what we have going on in December.
+
+### Upcoming events
+
+A significant part of the Python community is its in-person events. These events are where users and contributors intermingle and learn together. Here are the big announcements of upcoming opportunities to connect.
+
+#### PyCon US 2020
+
+[PyCon US][2] is by far the largest annual Python event. The next PyCon is April 15-23, 2020, in Pittsburgh. The call for proposals is open to all until December 20, 2019. I’m planning to attend PyCon for the conference and its [famous post-con sprints][3].
+
+#### EuroPython
+
+EuroPython is the largest Python conference in Europe with about 1,000 attendees in the last years. [EP20][4] will be held in Dublin, Ireland, July 20-26, 2020. As a liaison for Red Hat, I’m proud to say that Red Hat sponsored EP18 in Edinburgh and donated the sponsoring tickets to Women Who Code Scotland.
+
+#### PyData
+
+[PyData][5] is a separate nonprofit related to the Python community through a focus on data science. They host many international events throughout the year, with upcoming events in [Austin, Texas][6], and [Warsaw, Poland][7] before the end of the year.
+
+### New PSF fellows from Africa
+
+The PSF promotes a few members to fellow every quarter. Yesterday, twelve new PSF fellows were [announced][8].
+
+I’d like to highlight the four new fellows from Ghana, who are also the organizers of the first pan-African [PyCon Africa][9], which took place in August 2019 in Accra, Ghana. The Python community in Africa is growing at an amazing speed. PyCon Africa 2020 will be in Accra again, and I’m planning to spend my summer vacation there.
+
+### Annual release cycle for Python
+
+Python used to release a new major version about every 18 months. This timeline will change with the Python 3.9 release. With [PEP 602,][10] a new major version of Python will be released annually in October. The new cadence means fewer changes between releases and more predictable release dates. October was chosen to align with Linux distribution releases such as Fedora. Miro Hrončok from the Python maintenance team joined the discussion and has helped to find a convenient release date for us; for more details, please see .
+
+### Steering council election
+
+The Python Steering Council governs the development of Python. It was established after [Guido van Rossum stepped down][11] as benevolent dictator for life. Python core developers elect a new steering council for every major Python release. For the upcoming term, nine candidates were nominated for five seats on the council (with Guido being nominated, but [withdrawing][12]). See for all the details. Election results are expected to be announced mid-December.
+
+That covers what’s new in the Python community for December. Stay tuned for more updates in the future and mark your calendars for the conferences mentioned above.
+
+So you have a great business idea for a wonderful IT product or service, and you want to build your...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/python-news-december
+
+作者：[Christian Heimes][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/christian-heimes
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/coffee_python.jpg?itok=G04cSvp_ (Python in a coffee cup.)
+[2]: https://us.pycon.org/2020/
+[3]: https://opensource.com/article/19/5/pycon-developer-sprints
+[4]: https://www.europython-society.org/post/188741002380/europython-2020-venue-and-location-selected
+[5]: https://pydata.org/
+[6]: https://pydata.org/austin2019/
+[7]: https://pydata.org/warsaw2019/
+[8]: https://pyfound.blogspot.com/2019/11/python-software-foundation-fellow.html
+[9]: https://africa.pycon.org/
+[10]: https://www.python.org/dev/peps/pep-0602/
+[11]: https://opensource.com/article/19/6/command-line-heroes-python
+[12]: https://discuss.python.org/t/steering-council-nomination-guido-van-rossum-2020-term/2657/11
diff --git a/sources/news/20191219 2020 technology must haves, a guide to Kubernetes etcd, and more industry trends.md b/sources/news/20191219 2020 technology must haves, a guide to Kubernetes etcd, and more industry trends.md
new file mode 100644
index 0000000000..198d4f8292
--- /dev/null
+++ b/sources/news/20191219 2020 technology must haves, a guide to Kubernetes etcd, and more industry trends.md
@@ -0,0 +1,63 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (2020 technology must haves, a guide to Kubernetes etcd, and more industry trends)
+[#]: via: (https://opensource.com/article/19/12/gartner-ectd-and-more-industry-trends)
+[#]: author: (Tim Hildred https://opensource.com/users/thildred)
+
+2020 technology must haves, a guide to Kubernetes etcd, and more industry trends
+======
+A weekly look at open source community, market, and industry trends.
+![Person standing in front of a giant computer screen with numbers, data][1]
+
+As part of my role as a senior product marketing manager at an enterprise software company with an open source development model, I publish a regular update about open source community, market, and industry trends for product marketers, managers, and other influencers. Here are five of my and their favorite articles from that update.
+
+## [Gartner's top 10 infrastructure and operations trends for 2020][2]
+
+> “The vast majority of organisations that do not adopt a shared self-service platform approach will find that their DevOps initiatives simply do not scale,” said Winser. "Adopting a shared platform approach enables product teams to draw from an I&O digital toolbox of possibilities, while benefiting from high standards of governance and efficiency needed for scale."
+
+**The impact**: The breakneck change of technology development and adoption will not slow down next year, as the things you've been reading about for the last two years become things you have to figure out to deal with every day.
+
+## [A guide to Kubernetes etcd: All you need to know to set up etcd clusters][3]
+
+> Etcd is a distributed reliable key-value store which is simple, fast and secure. It acts like a backend service discovery and database, runs on different servers in Kubernetes clusters at the same time to monitor changes in clusters and to store state/configuration data that should to be accessed by a Kubernetes master or clusters. Additionally, etcd allows Kubernetes master to support discovery service so that deployed application can declare their availability for inclusion in service.
+
+**The impact**: This is actually way more than I needed to know about setting up etcd clusters, but now I have a mental model of what that could look like, and you can too.
+
+## [How the open source model could fuel the future of digital marketing][4]
+
+> In other words, the broad adoption of open source culture has the power to completely invert the traditional marketing funnel. In the future, prospective customers could be first introduced to “late funnel” materials and then buy into the broader narrative — a complete reversal of how traditional marketing approaches decision-makers today.
+
+**The impact**: The SEO on this cuts two ways: It can introduce uninitiated marketing people to open source and uninitiated technical people to the ways that technology actually gets adopted. Neat!
+
+## [Kubernetes integrates interoperability, storage, waits on sidecars][5]
+
+> In a [recent interview][6], Lachlan Evenson, and was also a lead on the Kubernetes 1.16 release, said sidecar containers was one of the features that team was a “little disappointed” it could not include in their release.
+>
+> Guinevere Saenger, software engineer at GitHub and lead for the 1.17 release team, explained that sidecar containers gained increased focus “about a month ago,” and that its implementation “changes the pod spec, so this is a change that affects a lot of areas and needs to be handled with care.” She noted that it did move closer to completion and “will again be prioritized for 1.18.”
+
+**The impact**: You can read between the lines to understand a lot more about the Kubernetes sausage-making process. It's got governance, tradeoffs, themes, and timeframes; all the stuff that is often invisible to consumers of a project.
+
+_I hope you enjoyed this list of what stood out to me from last week and come back next Monday for more open source community, market, and industry trends._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/gartner-ectd-and-more-industry-trends
+
+作者：[Tim Hildred][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/thildred
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/data_metrics_analytics_desktop_laptop.png?itok=9QXd7AUr (Person standing in front of a giant computer screen with numbers, data)
+[2]: https://www.information-age.com/gartner-top-10-infrastructure-and-operations-trends-2020-123486509/
+[3]: https://superuser.openstack.org/articles/a-guide-to-kubernetes-etcd-all-you-need-to-know-to-set-up-etcd-clusters/
+[4]: https://www.forbes.com/sites/forbescommunicationscouncil/2019/11/19/how-the-open-source-model-could-fuel-the-future-of-digital-marketing/#71b602fb20a5
+[5]: https://www.sdxcentral.com/articles/news/kubernetes-integrates-interoperability-storage-waits-on-sidecars/2019/12/
+[6]: https://kubernetes.io/blog/2019/12/06/when-youre-in-the-release-team-youre-family-the-kubernetes-1.16-release-interview/
diff --git a/sources/news/20191219 Linux Mint 19.3 -Tricia- Released- Here-s What-s New and How to Get it.md b/sources/news/20191219 Linux Mint 19.3 -Tricia- Released- Here-s What-s New and How to Get it.md
new file mode 100644
index 0000000000..507915626b
--- /dev/null
+++ b/sources/news/20191219 Linux Mint 19.3 -Tricia- Released- Here-s What-s New and How to Get it.md
@@ -0,0 +1,165 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Linux Mint 19.3 “Tricia” Released: Here’s What’s New and How to Get it)
+[#]: via: (https://itsfoss.com/linux-mint-19-3/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+Linux Mint 19.3 “Tricia” Released: Here’s What’s New and How to Get it
+======
+
+_**Linux Mint 19.3 “Tricia” has been released. See what’s new in it and learn how to upgrade to Linux Mint 19.3.**_
+
+The Linux Mint team finally announced the release of Linux Mint 19.3 codenamed ‘Tricia’ with useful feature additions along with a ton of improvements under-the-hood.
+
+This is a point release based on the latest **Ubuntu 18.04.3** and it comes packed with the **Linux kernel 5.0**.
+
+I downloaded and quickly tested the edition featuring the [Cinnamon 4.4][1] desktop environment. You may also try the Xfce or MATE edition of Linux Mint 19.3.
+
+### Linux Mint 19.3: What’s New?
+
+![Linux Mint 19 3 Desktop][2]
+
+While being an LTS release that will be supported until 2023 – it brings in a couple of useful features and improvements. Let me highlight some of them for you.
+
+#### System Reports
+
+![][3]
+
+Right after installing Linux Mint 19.3 (or upgrading it), you will notice a warning icon on the right side of the panel (taskbar).
+
+When you click on it, you should be displayed a list of potential issues that you can take care of to ensure the best out of Linux Mint experience.
+
+For starters, it will suggest that you should create a root password, install a language pack, or update software packages – in the form of a warning. This is particularly useful to make sure that you perform important actions even after following the first set of steps on the welcome screen.
+
+#### Improved Language Settings
+
+Along with the ability to install/set a language, you will also get the ability to change the time format.
+
+So, the language settings are now more useful than ever before.
+
+#### HiDPI Support
+
+As a result of [HiDPI][4] support, the system tray icons will look crisp and overall, you should get a pleasant user experience on a high-res display.
+
+#### New Applications
+
+![Linux Mint Drawing App][5]
+
+With the new release, you will n longer find “**GIMP**” pre-installed.
+
+Even though GIMP is a powerful utility, they decided to add a simpler “**Drawing**” app to let users to easily crop/resize images while being able to tweak it a little.
+
+Also, **Gnote** replaces **Tomboy** as the default note-taking application on Linux Mint 19.3
+
+In addition to both these replacements, Celluloid video player has also been added instead of Xplayer. In case you did not know, Celluloid happens to be one of the [best open source video players][6] for Linux.
+
+#### Cinnamon 4.4 Desktop
+
+![Cinnamon 4 4 Desktop][7]
+
+In my case, the new Cinnamon 4.4 desktop experience introduces a couple of new abilities like adjusting/tweaking the panel zones individually as you can see in the screenshot above.
+
+#### Other Improvements
+
+There are several other improvements including more customizability options in the file manager and so on.
+
+You can read more about the detailed changes in the [official release notes][8].
+
+[Subscribe to our YouTube channel for more Linux videos][9]
+
+### Linux Mint 19 vs 19.1 vs 19.2 vs 19.3: What’s the difference?
+
+You probably already know that Linux Mint releases are based on Ubuntu long term support releases. Linux Mint 19 series is based on Ubuntu 18.04 LTS.
+
+Ubuntu LTS releases get ‘point releases’ on the interval of a few months. Point release basically consists of bug fixes and security updates that have been pushed since the last release of the LTS version. This is similar to the Service Pack concept in Windows XP if you remember it.
+
+If you are going to download Ubuntu 18.04 which was released in April 2018 in 2019, you’ll get Ubuntu 18.04.2. The ISO image of 18.04.2 will consist of 18.04 and the bug fixes and security updates applied till 18.04.2. Imagine if there were no point releases, then right after [installing Ubuntu 18.04][10], you’ll have to install a few gigabytes of system updates. Not very convenient, right?
+
+But Linux Mint has it slightly different. Linux Mint has a major release based on Ubuntu LTS release and then it has three minor releases based on Ubuntu LTS point releases.
+
+Mint 19 was based on Ubuntu 18.04, 19.1 was based on 18.04.1 and Mint 19.2 is based on Ubuntu 18.04.2. Similarly, Mint 19.3 is based on Ubuntu 18.04.3. It is worth noting that all Mint 19.x releases are long term support releases and will get security updates till 2023.
+
+Now, if you are using Ubuntu 18.04 and keep your system updated, you’ll automatically get updated to 18.04.1, 18.04.2 etc. That’s not the case in Linux Mint.
+
+Linux Mint minor releases also consist of _feature changes_ along with bug fixes and security updates and this is the reason why updating Linux Mint 19 won’t automatically put you on 19.1.
+
+Linux Mint gives you the option if you want the new features or not. For example, Mint 19.3 has Cinnamon 4.4 and several other visual changes. If you are happy with the existing features, you can stay on Mint 19.2. You’ll still get the necessary security and maintenance updates on Mint 19.2 till 2023.
+
+Now that you understand the concept of minor releases and want the latest minor release, let’s see how to upgrade to Mint 19.3.
+
+### Linux Mint 19.3: How to Upgrade?
+
+No matter whether you have Linux Mint 19.1 or 19, you can follow these steps to [upgrade Linux Mint version][11].
+
+**Note**: _You should consider making a system snapshot (just in case) for backup. In addition, the Linux Mint team advises you to disable the screensaver and upgrade Cinnamon spices (if installed) from the System settings._
+
+![][12]
+
+ 1. Launch the Update Manager.
+ 2. Now, refresh it to load up the latest available updates (or you can change the mirror if you want).
+ 3. Once done, simply click on the Edit button to find “**Upgrade to Linux Mint 19.3 Tricia**” button similar to the image above.
+ 4. Finally, just follow the on-screen instructions to easily update it.
+
+
+
+Based on your internet connection, it should take anything between a couple of minutes to 30 minutes.
+
+### Don’t see Mint 19.3 update yet? Here’s what you can do
+
+If you don’t see the option to upgrade to Linux Mint 19.3 Tricia, don’t lose hope. Here are a couple of things you can do.
+
+#### **Step 1: Make sure to use mint-upgrade-info version 1.1.3**
+
+Make sure that mint-upgrade-info is updated to version 1.1.3. You can try the install command that will update it to a newer version (if there is any).
+
+```
+sudo apt install mint-upgrade-info
+```
+
+#### **Step 2: Switch to default software sources**
+
+Chances are that you are using a mirror closer to you to get faster software downloads. But this could cause a problem as the mirrors might not have the new upgrade info yet.
+
+Go to Software Source and change the sources to default. Now run the update manager again and see if Mint 19.3 upgrade is available.
+
+### Download Linux Mint 19.3 ‘Tricia’
+
+If you want to perform a fresh install, you can easily download the latest available version from the official download page (depending on what edition you want).
+
+You will also find multiple mirrors available to download the ISOs – feel free to try the nearest mirror for potentially faster download.
+
+[Linux Mint 19.3][13]
+
+**Wrapping Up**
+
+Have you tried Linux Mint 19.3 yet? Let me know your thoughts in the comments down below.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/linux-mint-19-3/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://github.com/linuxmint/cinnamon/releases/tag/4.4.0
+[2]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/linux-mint-19-3-desktop.jpg?ssl=1
+[3]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/linux-mint-system-report.jpg?ssl=1
+[4]: https://wiki.archlinux.org/index.php/HiDPI
+[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/linux-mint-drawing-app.jpg?ssl=1
+[6]: https://itsfoss.com/video-players-linux/
+[7]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/cinnamon-4-4-desktop.jpg?ssl=1
+[8]: https://linuxmint.com/rel_tricia_cinnamon.php
+[9]: https://www.youtube.com/c/itsfoss?sub_confirmation=1
+[10]: https://itsfoss.com/things-to-do-after-installing-ubuntu-18-04/
+[11]: https://itsfoss.com/upgrade-linux-mint-version/
+[12]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/08/mintupgrade.png?ssl=1
+[13]: https://linuxmint.com/download.php
diff --git a/sources/news/20191221 Eliminating gender bias in open source software development, a database of microbes, and more open source news.md b/sources/news/20191221 Eliminating gender bias in open source software development, a database of microbes, and more open source news.md
new file mode 100644
index 0000000000..3cf9d05097
--- /dev/null
+++ b/sources/news/20191221 Eliminating gender bias in open source software development, a database of microbes, and more open source news.md
@@ -0,0 +1,76 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Eliminating gender bias in open source software development, a database of microbes, and more open source news)
+[#]: via: (https://opensource.com/article/19/12/news-december-21)
+[#]: author: (Scott Nesbitt https://opensource.com/users/scottnesbitt)
+
+Eliminating gender bias in open source software development, a database of microbes, and more open source news
+======
+Catch up on the biggest open source headlines from the past two weeks.
+![Weekly news roundup with TV][1]
+
+In this edition of our open source news roundup, we take a look at eliminating gender bias in open source software development, an open source database of microbes, an open source index for cooperatives, and more!
+
+### Eliminating gender bias from open source development
+
+It's a sad fact that certain groups, among them women, are woefully underrepresented in open source projects. It's like a bug in the open source development process. Fortunately, there are initiatives to make that under representation a thing of the past. A study out of Oregon State University (OSU) intends to resolve the issue of the lack of women in open source development by "[finding these bugs and proposing redesigns around them][2], leading to more gender-inclusive tools used by software developers."
+
+The study will look at tools commonly used in open source development — including Eclipse, GitHub, and Hudson — to determine if they "significantly discourage newcomers, especially women, from joining OSS projects." According to Igor Steinmacher, one of the principal investigators of the study, the study will examine "how people use tools because the 'bugs' may be embedded in how the tool was designed, which may place people with different cognitive styles at a disadvantage."
+
+The developers of the tools being studied will walk through their software and answer questions based on specific personas. The researchers at OSU will suggest ways to redesign the software to eliminate gender bias and will "create a list of best practices for fixing gender-bias bugs in both products and processes."
+
+### Canadian university compiles open source microbial database
+
+What do you do when you have a vast amount of data but no way to effectively search and build upon it? You turn it into a database, of course. That's what researchers at Simon Fraser University in British Columbia, along with collaborators from around the globe, did with [information about chemical compounds created by bacteria and fungi][3]. Called the Natural Products Atlas, the database "holds information on nearly 25,000 natural compounds and serves as a knowledge base and repository for the global scientific community."
+
+Licensed under a Creative Commons Attribution 4.0 International License, the Natural Products Atlas "holds information on nearly 25,000 natural compounds and serves as a knowledge base and repository for the global scientific community." The [website for the Natural Products Atlas][4] hosts the database also includes a number of visualization tools and is fully searchable.
+
+Roger Linington, an associate professor at SFU who spearheaded the creation of the database, said that having "all the available data in one place and in a standardized format means we can now index natural compounds for anyone to freely access and learn more about."
+
+### Open source index for cooperatives
+
+Europe has long been a hotbed of both open source development and open source adoption. While European governments strongly advocate open source, non profits have been following suit. One of those is Cooperatives Europe, which is developing "[open source software to allow users to index co-op information and resources in a standardised way][5]."
+
+The idea behind the software, called Coop Starter, reinforces the [essential freedoms of free software][6]: it's intended to provide "education, training and information. The software may be used and repurposed by the public for their own needs and on their own infrastructure." Anyone can use it "to reference existing material on co-operative entrepreneurship" and can contribute "by sharing resources and information."
+
+The [code for Coop Starter][7], along with a related WordPress plugin, is available from Cooperative Europe's GitLab repository.
+
+#### In other news
+
+ * [Nancy recognised as France’s top digital free and collaborative public service][8]
+ * [Open Source and AI: Ready for primetime in government?][9]
+ * [Open Software Means Kinder Science][10]
+ * [New Open-Source CoE to be launched by Wipro and Oman’s Ministry of Tech & Communication][11]
+
+
+
+_Thanks, as always, to Opensource.com staff members and [Correspondents][12] for their help this week._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/news-december-21
+
+作者：[Scott Nesbitt][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/scottnesbitt
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/weekly_news_roundup_tv.png?itok=B6PM4S1i (Weekly news roundup with TV)
+[2]: https://techxplore.com/news/2019-12-professors-gender-biased-bugs-open-source-software.html
+[3]: https://www.sfu.ca/sfunews/stories/2019/12/sfu-global-collaboration-creates-world-s-first-open-source-datab.html
+[4]: https://www.npatlas.org/joomla/
+[5]: https://www.thenews.coop/144412/sector/regional-organisations/cooperatives-europe-builds-open-source-index-for-the-co-op-movement/
+[6]: https://www.gnu.org/philosophy/free-sw.en.html
+[7]: https://git.happy-dev.fr/startinblox/applications/coop-starter
+[8]: https://joinup.ec.europa.eu/collection/open-source-observatory-osor/news/territoire-numerique-libre
+[9]: https://federalnewsnetwork.com/commentary/2019/12/open-source-and-ai-ready-for-primetime-in-government/
+[10]: https://blogs.scientificamerican.com/observations/open-software-means-kinder-science/
+[11]: https://www.indianweb2.com/2019/12/11/new-open-source-coe-to-be-launched-by-wipro-and-omans-ministry-of-tech-communication/
+[12]: https://opensource.com/correspondent-program
diff --git a/sources/news/20191226 Darktable 3 Released With GUI Rework and New Features.md b/sources/news/20191226 Darktable 3 Released With GUI Rework and New Features.md
new file mode 100644
index 0000000000..665f5f585a
--- /dev/null
+++ b/sources/news/20191226 Darktable 3 Released With GUI Rework and New Features.md
@@ -0,0 +1,112 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Darktable 3 Released With GUI Rework and New Features)
+[#]: via: (https://itsfoss.com/darktable-3-release/)
+[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
+
+Darktable 3 Released With GUI Rework and New Features
+======
+
+Here’s the Christmas gift for the photography enthusiasts. Darktable 3.0 has just released.
+
+[Darktable][1] is one of the [best applications for editing RAW images on Linux][2]. You can consider it as a [free and open source alternative to Adobe Lightroom][3].
+
+Darktable 3 is a major new release with tons of feature improvements and a complete rework of the user interface. The GUI is now completely controlled by GTK+ CSS rules, which makes the whole GUI themable. There are eight themes available by default.
+
+With the help of over 3000 commits and 553 pull requests, the new release has fixed 66 bugs and added many new features.
+
+Let’s see what features this new release brings.
+
+### New features in Darktable 3.0
+
+![Darktable 3.0 Screenshot][4]
+
+Here are the highlighted new features:
+
+ * Reworked UI
+ * A new module for handling 3D RGB Lut transformations
+ * Many improvements to the ‘denoise (profiled)’ module
+ * A new ‘culling’ mode and timeline view added
+ * Many improvements to the ‘denoise (profiled)’ module
+ * New tone equalizer’ basic and filmic RGB modules
+ * Better 4K/5K display support
+ * Undo/redo support for more operations
+ * Many code optimizations for CPU and SSE paths
+ * Support for exporting to Google Photos
+ * More camera support, white balance presets, and noise profiles
+ * Plenty of bug fixes and feature improvements
+
+
+
+You can read about all the changes in the [release notes on GitHub][5].
+
+### Installing Darktable 3.0 on Linux
+
+Let’s see how to get the latest Darktable release.
+
+#### Installing Darktable 3.0 on Ubuntu-based distributions
+
+Darktable is available in Ubuntu but you won’t get the latest release immediately. For the LTS version, it may take months before you have this version update.
+
+Worry not! Darktable provides its [own PPA][6] to install the latest release on Ubuntu-based distributions.
+
+Unfortuntaley, That Darktable PPA has not been updated with the new release.
+
+Worry not (again)! Thanks to our friend [Ji M of Ubuntu Handbook][7], we have an unofficial PPA for easily installing Darktable 3.0 on Ubuntu and other Ubuntu based distributions.
+
+Open a terminal and use these commands one by one:
+
+```
+sudo add-apt-repository ppa:ubuntuhandbook1/darktable
+sudo apt update
+sudo apt install darktable
+```
+
+#### Uninstall Darktable 3
+
+To remove Darktable installed via this PPA, you can first uninstall the application:
+
+```
+sudo apt remove darktable
+```
+
+And then [remove the PPA][8] as well:
+
+```
+sudo add-apt-repository -r ppa:ubuntuhandbook1/darktable
+```
+
+#### Installing Darktable on other Linux distributions
+
+You may wait for your distribution to provide this new release through the software manager.
+
+You may also download the tarball or the entire source code from the GitHub release page (it’s at the bottom of the page).
+
+[Download Darktable 3.0][5]
+
+With Darktable 3, you can edit your holiday pictures better :)
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/darktable-3-release/
+
+作者：[Abhishek Prakash][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/abhishek/
+[b]: https://github.com/lujun9972
+[1]: https://www.darktable.org/
+[2]: https://itsfoss.com/raw-image-tools-linux/
+[3]: https://itsfoss.com/open-source-photoshop-alternatives/
+[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/darktable_3_screenshot.jpg?ssl=1
+[5]: https://github.com/darktable-org/darktable/releases/tag/release-3.0.0
+[6]: https://launchpad.net/~pmjdebruijn/+archive/ubuntu/darktable-release
+[7]: http://ubuntuhandbook.org/index.php/2019/12/install-darktable-3-0-0-ubuntu-18-04-19-10/
+[8]: https://itsfoss.com/how-to-remove-or-delete-ppas-quick-tip/
diff --git a/sources/talk/20181018 Think global- How to overcome cultural communication challenges.md b/sources/talk/20181018 Think global- How to overcome cultural communication challenges.md
deleted file mode 100644
index 1244f13079..0000000000
--- a/sources/talk/20181018 Think global- How to overcome cultural communication challenges.md
+++ /dev/null
@@ -1,95 +0,0 @@
-translating
-
-Think global: How to overcome cultural communication challenges
-======
-Use these tips to ensure that every member of your global development team feels involved and understood.
-
-
-A few weeks ago, I witnessed an interesting interaction between two work colleagues—Jason, who is from the United States; and Raj, who was visiting from India.
-
-Raj typically calls into a daily standup meeting at 9:00am US Central Time from India, but since he was in the US, he and his teammates headed toward the scrum area for the meeting. Jason stopped Raj and said, “Raj, where are you going? Don’t you always call into the stand-up? It would feel strange if you don’t call in.” Raj responded, “Oh, is that so? No worries,” and headed back to his desk to call into the meeting.
-
-I went to Raj’s desk. “Hey, Raj, why aren’t you going to the daily standup?” Raj replied, “Jason asked me to call in.” Meanwhile, Jason was waiting for Raj to come to the standup.
-
-What happened here? Jason was obviously joking when he made the remark about Raj calling into the meeting. But how did Raj miss this?
-
-Jason’s statement was meant as a joke, but Raj took it literally. This was a clear example of a misunderstanding that occurred due to unfamiliarity with each other’s cultural context.
-
-I often encounter emails that end with “Please revert back to me.” At first, this phrase left me puzzled. I thought, "What changes do they want me to revert?" Finally, I figured out that “please revert” means “Please reply.”
-
-In his TED talk, “[Managing Cross Cultural Remote Teams,][1]” Ricardo Fernandez describes an interaction with a South African colleague who ended an IM conversation with “I’ll call you just now.” Ricardo went back to his office and waited for the call. After fifteen minutes, he called his colleague: “Weren’t you going to call me just now?” The colleague responded, “Yes, I was going to call you just now.” That's when Ricardo realized that to his South African colleague, the phrase “just now” meant “sometime in the future.”
-
-In today's workplace, our colleagues may not be located in the same office, city, or even country. A growing number of tech companies have a global workforce comprised of employees with varied experiences and perspectives. This diversity allows companies to compete in the rapidly evolving technological environment.
-
-But geographically dispersed teams can face challenges. Managing and maintaining high-performing development teams is difficult even when the members are co-located; when team members come from different backgrounds and locations, that makes it even harder. Communication can deteriorate, misunderstandings can happen, and teams may stop trusting each other—all of which can affect the success of the company.
-
-What factors can cause confusion in global communication? In her book, “[The Culture Map][2],” Erin Meyer presents eight scales into which all global cultures fit. We can use these scales to improve our relationships with international colleagues. She identifies the United States as a very low-context culture in the communication scale. In contrast, Japan is identified as a high-context culture.
-
-What does it mean to be a high- or low-context culture? In the United States, children learn to communicate explicitly: “Say what you mean; mean what you say” is a common principle of communication. On the other hand, Japanese children learn to communicate effectively by mastering the ability to “read the air.” That means they are able to read between the lines and pick up on social cues when communicating.
-
-Most Asian cultures follow the high-context style of communication. Not surprisingly, the United States, a young country composed of immigrants, follows a low-context culture: Since the people who immigrated to the United States came from different cultural backgrounds, they had no choice but to communicate explicitly and directly.
-
-### The three R’s
-
-How can we overcome challenges in cross-cultural communication? Americans communicating with Japanese colleagues, for example, should pay attention to the non-verbal cues, while Japanese communicating with Americans should prepare for more direct language. If you are facing a similar challenge, follow these three steps to communicate more effectively and improve relationships with your international colleagues.
-
-#### Recognize the differences in cultural context
-
-The first step toward effective cross-cultural communication is to recognize that there are differences. Start by increasing your awareness of other cultures.
-
-#### Respect the differences in cultural context
-
-Once you become aware that differences in cultural context can affect cross-cultural communication, the next step is to respect these differences. When you notice a different style of communication, learn to embrace the difference and actively listen to the other person’s point of view.
-
-#### Reconcile the differences in cultural context
-
-Merely recognizing and respecting cultural differences is not enough; you must also learn how to reconcile the cultural differences. Understanding and being empathetic towards the other culture will help you reconcile the differences and learn how to use them to better advance productivity.
-
-### 5 ways to improve communications for cultural context
-
-Over the years, I have incorporated various approaches, tips, and tricks to strengthen relationships among team members across the globe. These approaches have helped me overcome communication challenges with global colleagues. Here are a few examples:
-
-#### Always use video conferencing when communicating with global teammates
-
-Studies show that about 55% of communication is non-verbal. Body language offers many subtle cues that can help you decipher messages, and video conferencing enables geographically dispersed team members to see each other. Videoconferencing is my default choice when conducting remote meetings.
-
-#### Ensure that every team member gets an opportunity to share their thoughts and ideas
-
-Although I prefer to conduct meetings using video conferencing, this is not always possible. If video conferencing is not a common practice at your workplace, it might take some effort to get everyone comfortable with the concept. Start by encouraging everyone to participate in audio meetings.
-
-One of our remote team members, who frequently met with us in audio conferences, mentioned that she often wanted to share ideas and contribute to the meeting but since we couldn’t see her and she couldn’t see us, she had no idea when to start speaking. If you are using audio conferencing, one way to mitigate this is to ensure that every team member gets an opportunity to share their ideas.
-
-#### Learn from one another
-
-Leverage your international friends to learn about their cultural context. This will help you interact more effectively with colleagues from these countries. I have friends from South Asia and South America who have helped me better understand their cultures, and this knowledge has helped me professionally.
-
-For programmers, I recommend conducting code reviews with your global peers. This will help you understand how those from different cultures give and receive feedback, persuade others, and make technical decisions.
-
-#### Be empathetic
-
-Empathy is the key to strong relationships. The more you are able to put yourself in someone else's shoes, the better able you will be to gain trust and build long-lasting connections. Encourage “water-cooler” conversations among your global colleagues by allocating the first few minutes of each meeting for small talk. This offers the additional benefit of putting everyone in a more relaxed mindset. If you manage a global team, make sure every member feels included in the discussion.
-
-#### Meet your global colleagues in person
-
-The best way to build long-lasting relationships is to meet your team members in person. If your company can afford it, arrange for this to happen. Meeting colleagues with whom you have been working will likely strengthen your relationship with them. The companies I have worked for have a strong record of periodically sending US team members to other countries and global colleagues to the US office.
-
-Another way to bring teams together is to attend conferences. This not only creates educational and training opportunities, but you can also carve out some in-person team time.
-
-In today's increasingly global economy, it is becoming more important for companies to maintain a geographically diverse workforce to remain competitive. Although global teams can face communication challenges, it is possible to maintain a high-performing development team despite geographical and cultural differences. Share some of the techniques you use in the comments.
-
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/18/10/think-global-communication-challenges
-
-作者：[Avindra Fernando][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/avindrafernando
-[b]: https://github.com/lujun9972
-[1]: https://www.youtube.com/watch?v=QIoAkFpN8wQ
-[2]: https://www.amazon.com/The-Culture-Map-Invisible-Boundaries/dp/1610392507
diff --git a/sources/talk/20191004 What-s in an open source name.md b/sources/talk/20191004 What-s in an open source name.md
deleted file mode 100644
index ae5ce6ee65..0000000000
--- a/sources/talk/20191004 What-s in an open source name.md
+++ /dev/null
@@ -1,198 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (laingke)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (What's in an open source name?)
-[#]: via: (https://opensource.com/article/19/10/open-source-name-origins)
-[#]: author: (Joshua Allen Holm https://opensource.com/users/holmja)
-
-What's in an open source name?
-======
-Ever wonder where the names of your favorite open source projects or
-programming languages came from? Get the origin stories behind popular
-tech nomenclature from A to Z.
-![A person writing.][1]
-
-GNOME, Java, Jupyter, Python. If your friends or family members have ever eavesdropped on your work conversations, they might think you've made a career in Renaissance folklore, coffee roasting, astronomy, or zoology. Where did the names of these open source technologies come from? We asked our writer community for input and rounded up some of our favorite tech name origin stories.
-
-### Ansible
-
-The name "Ansible" is lifted directly from science fiction. Ursula Le Guin's book _Rocannon's World_ had devices allowing instantaneous (faster than light) communication called ansibles (derived, apparently, from the word "answerable"). Ansibles became a staple of science fiction, including in Orson Scott Card's _Ender's Game_ (which later became a popular film), where the device controlled many remote space ships. This seemed to be a good model for software that controls distributed machines, so Michael DeHaan (creator and founder of Ansible) borrowed the name.
-
-### Apache
-
-[Apache][2] is an open source web server that was originally released in 1995. Its name is not related to the famous Native American tribe; it instead refers to the repeated patches to its original software code. Hence, "A-patchy server."
-
-### awk
-
-"awk(1) Stands for Aho, Weinberger, Kernighan (authors)" —Michael Greenberg
-
-### Bash
-
-"The original Unix shell, the Bourne shell, was named after its creator. At the time Bash was being developed, csh (pronounced 'seashell') was actually more popular for interactive user logins. The Bash project aimed to give new life to the Bourne shell by making it more suitable for interactive use, thus it was named the 'Bourne again shell,' a pun on 'born again.'" —Ken Gaillot
-
-### C
-
-"In early days, Ken Thompson and Dennis Ritchie at AT&T found it interesting that you could use a higher-level programming language (instead of low-level and less-portable assembly programming) to write operating systems and tools. There was an early programming system called BCPL (Basic Combined Programming Language), and Thompson created a stripped-down version of BCPL called B. But B wasn't very flexible or fast. Ritchie then took the ideas of B and expanded it into a compiled language called C." —Jim Hall
-
-### dd
-
-"I don't think you can publish such an article without mentioning dd. My nickname is Didi. Correctly pronounced, it sounds like 'dd.' I first learned Unix, and then Linux, in 1993 as a student. Then I went to the army, arrived to one of the very few sections in my unit that used Unix (Ultrix) (the rest were mainly VMS), and one of the people there said: 'So, you are a hacker, right? You think you know Unix? OK, so what's the reason for the name dd?' I had no idea and tried to guess: "Data duplicator?" So he said, 'I'll tell you the story of dd. dd is short for _convert and copy_ (as anyone can still see today on the manpage), but since cc was already taken by the c compiler, it was named dd.' Only years later, I heard the true story about JCL's data definition and the non-uniform, semi-joking syntax for the Unix dd command somewhat being based on it." —Yedidyah Bar David
-
-### Emacs
-
-The classic anti-vi editor, the true etymology of the name is unremarkable, in that it derives from "Editing MACroS." Being an object of great religious opprobrium and worship it has, however, attracted many spoof bacronyms such as "Escape Meta Alt Control Shift" (to spoof its heavy reliance on keystrokes), "Eight Megabytes And Constantly Swapping" (from when that was a lot of memory), "Eventually malloc()s All Computer Storage," and "EMACS Makes A Computer Slow." —Adapted from the Jargon File/Hacker's Dictionary
-
-### Enarx
-
-[Enarx][3] is a new project in the confidential computing space. One of the project's design principles was that it should be "fungible." so an initial name was "psilocybin" (the famed magic mushroom). The general feeling was that manager types would probably be resistant, so new names were considered. The project's two founders, Mike Bursell and Nathaniel McCallum, are both ancient language geeks, so they considered lots of different ideas, including тайна (Tayna—Russian for secret or mystery—although Russian, admittedly, is not ancient, but hey), crypticon (total bastardization of Greek), cryptidion (Greek for small secret place), arcanus (Latin masculine adjective for secret), arcanum (Latin neuter adjective for secret), and ærn (Anglo-Saxon for place, secret place, closet, habitation, house, or cottage). In the end, for various reasons, including the availability of domains and GitHub project names, they settled on enarx, a combination of two Latin roots: en- (meaning within) and -arx (meaning citadel, stronghold, or fortress).
-
-### GIMP
-
-Where would we be without [GIMP][4]? The GNU Image Manipulation Project has been an open source staple for many years. [Wikipedia][5] states, "In 1995, [Spencer Kimball][6] and [Peter Mattis][7] began developing GIMP as a semester-long project at the University of California, Berkeley, for the eXperimental Computing Facility."
-
-### GNOME
-
-Have you ever wondered why GNOME is called GNOME? According to [Wikipedia][8], GNOME was originally an acronym that represented the "GNU Network Object Model Environment." Now that name no longer represents the project and has been dropped, but the name has stayed. [GNOME 3][9] is the default desktop environment for Fedora, Red Hat Enterprise, Ubuntu, Debian, SUSE Linux Enterprise, and more.
-
-### Java
-
-Can you imagine this programming language being named anything else? Java was originally called Oak, but alas, the legal team at Sun Microsystems vetoed that name due to its existing trademark. So it was back to the drawing board for the development team. [Legend has it][10] that a massive brainstorm was held by the language's working group in January 1995. Lots of other names were tossed around including Silk, DNA, WebDancer, and so on. The team did not want the new name to have anything to do with the overused terms, "web" or "net." Instead, they were searching for something more dynamic, fun, and easy to remember. Java met the requirements and miraculously, the team agreed!
-
-### Jupyter
-
-Many of today's data scientists and students use [Jupyter][11] notebooks in their work. The name Jupyter is an amalgamation of three open source computer languages that are used in the notebooks and prominent in data science: [Julia][12], [Python][13], and [R][14].
-
-### Kubernetes
-
-Kubernetes is derived from the Greek word for helmsman. This etymology was corroborated in a [2015 Hacker News][15] response by a Kubernetes project founder, Craig McLuckie. Wanting to stick with the nautical theme, he explained that the technology drives containers, much like a helmsman or pilot drives a container ship. Thus, Kubernetes was the chosen name. Many of us are still trying to get the pronunciation right (koo-bur-NET-eez), so K8s is an acceptable substitute. Interestingly, it shares its etymology with the English word "governor," so has that in common with the mechanical negative-feedback device on steam engines.
-
-### KDE
-
-What about the K desktop? KDE originally represented the "Kool Desktop Environment." It was founded in 1996 by [Matthias Ettrich][16]. According to [Wikipedia][17], the name was a play on the words [Common Desktop Environment][18] (CDE) on Unix.
-
-### Linux
-
-[Linux][19] was named for its inventor, Linus Torvalds. Linus originally wanted to name his creation "Freax" as he thought that naming the creation after himself was too egotistical. According to [Wikipedia][19], "Ari Lemmke, Torvalds' coworker at the Helsinki University of Technology, who was one of the volunteer administrators for the FTP server at the time, did not think that 'Freax' was a good name. So, he named the project 'Linux' on the server without consulting Torvalds."
-
-Following are some of the most popular Linux distributions.
-
-#### CentOS
-
-[CentOS][20] is an acronym for Community Enterprise Operating System. It contains the upstream packages from Red Hat Enterprise Linux.
-
-#### Debian
-
-[Debian][21] Linux, founded in September 1993, is a portmanteau of its founder, Ian Murdock, and his then-girlfriend Debra Lynn.
-
-#### RHEL
-
-[Red Hat Linux][22] got its name from its founder Marc Ewing, who wore a red Cornell University fedora given to him by his grandfather. Red Hat was founded on March 26, 1993. [Fedora Linux][23] began as a volunteer project to provide extra software for the Red Hat distribution and got its name from Red Hat's "Shadowman" logo.
-
-#### Ubuntu
-
-[Ubuntu][24] aims to share open source widely and is named after the African philosophy of ubuntu, which can be translated as "humanity to others" or "I am what I am because of who we all are."
-
-### Moodle
-
-The open source learning platform [Moodle][25] is an acronym for "modular object-oriented dynamic learning environment." Moodle continues to be a leading platform for e-learning. There are nearly 104,000 registered Moodle sites worldwide.
-
-Two other popular open source content management systems are Drupal and Joomla. Drupal's name comes from the Dutch word for "druppel" which means "drop." Joomla is an [anglicized spelling][26] of the Swahili word "jumla," which means "all together" in Arabic, Urdu, and other languages, according to Wikipedia.
-
-### Mozilla
-
-[Mozilla][27] is an open source software community founded in 1998. According to its website, "The Mozilla project was created in 1998 with the release of the Netscape browser suite source code. It was intended to harness the creative power of thousands of programmers on the internet and fuel unprecedented levels of innovation in the browser market." The name was a portmanteau of [Mosaic][28] and Godzilla.
-
-### Nginx
-
-"Many tech people try to be cool and say it 'n' 'g' 'n' 'x'. Few actually did the basic actions of researching a bit more to find out very quickly that the name is actually supposed to be said as 'EngineX,' in reference to the powerful web server, like an engine." —Jean Sebastien Tougne
-
-### Perl
-
-Perl's founder Larry Wall originally named his project "Pearl." According to Wikipedia, Wall wanted to give the language a short name with positive connotations. Wall discovered the existing [PEARL][29] programming language before Perl's official release and changed the spelling of the name.
-
-### Piet and Mondrian
-
-"There are two programming language named after the artist Piet Mondrian. One is called 'Piet' and the other 'Mondrian.' [David Morgan-Mar [writes][30]]: 'Piet is a programming language in which programs look like abstract paintings. The language is named after Piet Mondrian, who pioneered the field of geometric abstract art. I would have liked to call the language Mondrian, but someone beat me to it with a rather mundane-looking scripting language. Oh well, we can't all be esoteric language writers, I suppose.'" —Yuval Lifshitz
-
-### Python
-
-The Python programming language received its unique name from its creator, Guido Van Rossum, who was a fan of the comedy group Monty Python.
-
-### Raspberry Pi
-
-Known for its tiny-but-mighty capabilities and wallet-friendly price tag, the Raspberry Pi is a favorite in the open source community. But where did its endearing (and yummy) name come from? In the '70s and '80s, it was a popular trend to name computers after fruit. Apple, Tangerine, Apricot... anyone getting hungry? According to a [2012 interview][31] with founder Eben Upton, the name "Raspberry Pi" is a nod to that trend. Raspberries are also tiny in size, yet mighty in flavor. The "Pi" in the name alludes to the fact that, originally, the computer could only run Python.
-
-### Samba
-
-[Server Message Block][32] for sharing Windows files on Linux.
-
-### ScummVM
-
-[ScummVM][33] (Script Creation Utility for Maniac Mansion Virtual Machine) is a program that makes it possible to run some classic computer adventure games on a modern computer. Originally, it was designed to play LucasArts adventure games that were built using SCUMM, which was originally used to develop Maniac Mansion before being used to develop most of LucasArts's other adventure games. Currently, ScummVM supports a large number of game engines, including Sierra Online's AGI and SCI, but still retains the name ScummVM. A related project, [ResidualVM][34], got its name because it covers the "residual" LucasArts adventure games not covered by ScummVM. The LucasArts games covered by ResidualVM were developed using GrimE (Grim Engine), which was first used to develop Grim Fandango, so the ResidualVM name is a double pun.
-
-### SQL
-
-"You may know [SQL] stands for Structured Query Language, but do you know why it's often pronounced 'sequel'? It was created as a follow-up (i.e. sequel) to the original 'QUEL' (QUEry Language)." —Ken Gaillot
-
-### XFCE
-
-[XFCE][35] is a popular desktop founded by [Olivier Fourdan][36]. It began as an alternative to CDE in 1996 and its name was originally an acronym for XForms Common Environment.
-
-### Zsh
-
-Zsh is an interactive login shell. In 1990, the first version of the shell was written by Princeton student Paul Falstad. He named it after seeing the login ID of Zhong Sha (zsh), then a teaching assistant at Princeton, and thought that it sounded like a [good name for a shell][37].
-
-There are many more projects and names that we have not included in this list. Be sure to share your favorites in the comments.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/open-source-name-origins
-
-作者：[Joshua Allen Holm][a]
-选题：[lujun9972][b]
-译者：[laingke](https://github.com/laingke)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/holmja
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/rh_003784_02_os.comcareers_resume_rh1x.png?itok=S3HGxi6E (A person writing.)
-[2]: https://httpd.apache.org/
-[3]: https://enarx.io
-[4]: https://www.gimp.org/
-[5]: https://en.wikipedia.org/wiki/GIMP
-[6]: https://en.wikipedia.org/wiki/Spencer_Kimball_(computer_programmer)
-[7]: https://en.wikipedia.org/wiki/Peter_Mattis
-[8]: https://en.wikipedia.org/wiki/GNOME
-[9]: https://www.gnome.org/gnome-3/
-[10]: https://www.javaworld.com/article/2077265/so-why-did-they-decide-to-call-it-java-.html
-[11]: https://jupyter.org/
-[12]: https://julialang.org/
-[13]: https://www.python.org/
-[14]: https://www.r-project.org/
-[15]: https://news.ycombinator.com/item?id=9653797
-[16]: https://en.wikipedia.org/wiki/Matthias_Ettrich
-[17]: https://en.wikipedia.org/wiki/KDE
-[18]: https://sourceforge.net/projects/cdesktopenv/
-[19]: https://en.wikipedia.org/wiki/Linux
-[20]: https://www.centos.org/
-[21]: https://www.debian.org/
-[22]: https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux
-[23]: https://getfedora.org/
-[24]: https://ubuntu.com/about
-[25]: https://moodle.org/
-[26]: https://en.wikipedia.org/wiki/Joomla#Historical_background
-[27]: https://www.mozilla.org/en-US/
-[28]: https://en.wikipedia.org/wiki/Mosaic_(web_browser)
-[29]: https://en.wikipedia.org/wiki/PEARL_(programming_language)
-[30]: http://www.dangermouse.net/esoteric/piet.html
-[31]: https://www.techspot.com/article/531-eben-upton-interview/
-[32]: https://www.samba.org/
-[33]: https://www.scummvm.org/
-[34]: https://www.residualvm.org/
-[35]: https://www.xfce.org/
-[36]: https://en.wikipedia.org/wiki/Olivier_Fourdan
-[37]: http://www.zsh.org/mla/users/2005/msg00951.html
diff --git a/sources/talk/20191204 Java vs. Python- Which should you choose.md b/sources/talk/20191204 Java vs. Python- Which should you choose.md
deleted file mode 100644
index edc59c7b3d..0000000000
--- a/sources/talk/20191204 Java vs. Python- Which should you choose.md
+++ /dev/null
@@ -1,157 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (geekpi)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Java vs. Python: Which should you choose?)
-[#]: via: (https://opensource.com/article/19/12/java-vs-python)
-[#]: author: (Archit Modi https://opensource.com/users/architmodi)
-
-Java vs. Python: Which should you choose?
-======
-Compare the two most popular programming languages in the world, and let
-us know which one you prefer in our poll.
-![Developing code.][1]
-
-Let's compare the two most popular and powerful programming languages in the world: Java and Python! Both languages have huge community support and libraries to perform almost any programming task, although selecting a programming language usually depends on the developer's use case. After you compare and contrast, please make sure to answer our poll to [share your opinion][2] on which is best.
-
-### What is it?
-
- * **Java** is a general-purpose object-oriented programming language used mostly for developing a wide range of applications from mobile to web to enterprise apps.
- * **Python** is a high-level object-oriented programming language used mostly for web development, artificial intelligence, machine learning, automation, and other data science applications.
-
-
-
-### Creator
-
- * **Java** was created by James Gosling (Sun Microsystems).
- * **Python** was created by Guido van Rossum.
-
-
-
-### Open source status
-
- * **Java** is free and (mostly) open source except for corporate use.
- * **Python** is free and open source for all use cases.
-
-
-
-### Platform dependencies
-
- * **Java** is platform-independent (although JVM isn't) per its WORA ("write once, run anywhere") philosophy.
- * **Python** is platform-dependent.
-
-
-
-### Compiled or interpreted
-
- * **Java** is a compiled language. Java programs are translated to byte code at compile time and not runtime.
- * **Python** is an interpreted language. Python programs are translated at runtime.
-
-
-
-### File creation
-
- * **Java**: After compilation, **<filename>.class** is generated.
- * **Python**: During runtime, **<filename>.pyc** is created.
-
-
-
-### Errors types
-
- * **Java** has ****2 ****types of errors: compile and runtime errors.
- * **Python** has 1 error type: traceback (or runtime) error.
-
-
-
-### Statically or dynamically typed
-
- * **Java** is statically typed. When initiating variables, their types need to be specified in the program because type checking is done at compile time.
- * **Python** is dynamically typed. Variables don't need to have a type specified when initiated because type checking is done at runtime.
-
-
-
-### Syntax
-
- * **Java**: Every statement needs to end with a semicolon ( **;** ), and blocks of code are separated by curly braces ( **{}** ).
- * **Python**: Blocks of code are separated by indentation (the user can choose how many white spaces to use, but it should be consistent throughout the block).
-
-
-
-### Number of classes
-
- * **Java**: Only one public top-level class can exist in a single file in Java.
- * **Python**: Any number of classes can exist in a single file in Python.
-
-
-
-### More or less code?
-
- * **Java** generally involves writing more lines of code compared to Python.
- * **Python** involves writing fewer lines of code compared to Java.
-
-
-
-### Multiple inheritance
-
- * **Java** does not support multiple inheritance (inheriting from two or more base classes)
- * **Python** supports multiple inheritance although it is rarely implemented due to various issues like inheritance complexity, hierarchy, dependency issues, etc.
-
-
-
-### Multi-threading
-
- * **Java** multi-threading can support two or more concurrent threads running at the same time.
- * **Python** uses a global interpreter lock (GIL), allowing only a single thread (CPU core) to run at a time.
-
-
-
-### Execution speed
-
- * **Java** is usually faster in execution time than Python.
- * **Python** is usually slower in execution time than Java.
-
-
-
-### Hello world in Java
-
-
-```
-public class Hello {
- public static void main([String][3][] args) {
- [System][4].out.println("Hello Opensource.com from Java!");
- }
-}
-```
-
-### Hello world in Python
-
-
-```
-`print("Hello Opensource.com from Java!")`
-```
-
-### Run the programs
-
-![Java vs. Python][5]
-
-To run the java program "Hello.java" you need to compile it first which creates a "Hello.class" file. To run just the class name, use "java Hello." For Python, you would just run the file "python3 helloworld.py."
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/12/java-vs-python
-
-作者：[Archit Modi][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/architmodi
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_development_programming.png?itok=M_QDcgz5 (Developing code.)
-[2]: tmp.Bpi8QYfp8j#poll
-[3]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+string
-[4]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+system
-[5]: https://opensource.com/sites/default/files/uploads/python-java-hello-world_0.png (Java vs. Python)
diff --git a/sources/talk/20191205 Researchers experiment with glass-based storage that doesn-t require electronics cooling.md b/sources/talk/20191205 Researchers experiment with glass-based storage that doesn-t require electronics cooling.md
new file mode 100644
index 0000000000..fdcf998fc8
--- /dev/null
+++ b/sources/talk/20191205 Researchers experiment with glass-based storage that doesn-t require electronics cooling.md
@@ -0,0 +1,85 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Researchers experiment with glass-based storage that doesn't require electronics cooling)
+[#]: via: (https://www.networkworld.com/article/3488556/researchers-experiment-with-glass-based-storage-that-doesnt-require-electronics-cooling.html)
+[#]: author: (Patrick Nelson https://www.networkworld.com/author/Patrick-Nelson/)
+
+Researchers experiment with glass-based storage that doesn't require electronics cooling
+======
+A Microsoft Research project uses laser optics and artificial intelligence to store data in quartz glass.
+Thinkstock
+
+Hard drives aren’t going to be capacious enough for future data archiving and retrieval requirements, scientists believe, as applications such as artificial intelligence, wide-scale Internet of Things connectivity, and virtual and augmented reality take hold. Glass could be the answer.
+
+Encoding in glass would have advantages over hard drives and other mediums, experts suggest. Holding capacity is greater, and the slivers of quartz being experimented with don’t need cooling or dehumidifying environments.
+
+Microsoft Research, working in the UK along with the University of Southampton, [announced][1] that it has been able to store an entire movie on a quartz, glass-based storage medium. The team stored and retrieved a full-length Superman film on a small slab of the special material that measures about 3 inches square and less than a tenth of an inch thick. .
+
+[][2]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][2]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+“It looks like we’re now in a phase where we’re working on refinement and experimentation, rather asking the question ‘can we do it?’” said Mark Russinovich, Microsoft Azure’s chief technology officer, in a statement.
+
+### Laser improvements fuel glass-based storage technology
+
+Improvements in laser technology are behind the proof of concept Microsoft Research dubbed Project Silica. The femtosecond infrared lasers that are used in the process function similarly to eye surgery lasers. Those kinds of laser beams are much better and more precise than traditional ones. They don’t crack the glass, for one thing.
+
+The glass is, in fact, structurally changed by the laser, which means that the data could last as long as the material does—possibly centuries, unlike existing mediums like tape. It’s robust, too. Interestingly, even if one were to break the glass, the data remains encoded in the shards, the researchers say.
+
+“It’s somewhat like creating upside down icebergs at a nanoscale level, with different depths and sizes and grooves that make them unique,” Microsoft said. Voxels, which are a three-dimensional version of a pixel, are embedded in the glass, one-time, rather than just written to the top, as occurs with other mediums. That three-dimensional aspect, along with the inherent opaqueness, helps with low-latency retrieval—the reading can occur rapidly along all of the axis (x, y and z).
+
+ * [Backup vs. archive: Why it’s important to know the difference][3]
+ * [How to pick an off-site data-backup method][4]
+ * [Tape vs. disk storage: Why isn’t tape dead yet?][5]
+ * [The correct levels of backup save time, bandwidth, space][6]
+
+
+
+### Cloud storage alternatives
+
+Glass isn’t the only potential replacement for old-school magnetic, solid-state and tape storage as the world increasingly collects data. Chemical, molecule and DNA options are all being suggested as potential alternatives to existing cloud storage.
+
+Fitting transistors onto individual molecules is one answer, [say researchers at Arizona State University][7].
+
+Synthetic DNA is another proposed option. Large amounts of information last a long time in DNA; a 45,000-year-old human bone was DNA-decoded a few years ago, for example. [Synthetic DNA could end up having similar advantages to that organic version][8], scientists think.
+
+A third option, at a chemical level, is storing data on molecules and then dissolving that mix into liquids. [Massive amounts of data could be held in small containers][9], Brown University has said of its experiments in that area.
+
+Perhaps most interestingly, with all of the these potential storage replacements (should any of them take off), the traditional environmental controls that we require for heat-generating electronics in data center environments would become moot.
+
+“Quartz glass doesn’t need energy-intensive air conditioning to keep material at a constant temperature or systems that remove moisture from the air,” Microsoft said of Project Silica. “Both of which could lower the environmental footprint of large-scale data storage.”
+
+Join the Network World communities on [Facebook][10] and [LinkedIn][11] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3488556/researchers-experiment-with-glass-based-storage-that-doesnt-require-electronics-cooling.html
+
+作者：[Patrick Nelson][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Patrick-Nelson/
+[b]: https://github.com/lujun9972
+[1]: https://news.microsoft.com/innovation-stories/ignite-project-silica-superman/
+[2]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[3]: https://www.networkworld.com/article/3285652/storage/backup-vs-archive-why-its-important-to-know-the-difference.html
+[4]: https://www.networkworld.com/article/3328488/backup-systems-and-services/how-to-pick-an-off-site-data-backup-method.html
+[5]: https://www.networkworld.com/article/3315156/storage/tape-vs-disk-storage-why-isnt-tape-dead-yet.html
+[6]: https://www.networkworld.com/article/3302804/storage/the-correct-levels-of-backup-save-time-bandwidth-space.html
+[7]: https://www.networkworld.com/article/3344599/new-chemistry-based-data-storage-would-blow-moores-law-out-of-the-water.html
+[8]: https://www.networkworld.com/article/3268646/dna-data-storage-closer-to-becoming-reality.html
+[9]: https://www.networkworld.com/article/3251071/data-could-one-day-be-stored-on-molecules.html
+[10]: https://www.facebook.com/NetworkWorld/
+[11]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191205 The current state of blockchain and where it-s going.md b/sources/talk/20191205 The current state of blockchain and where it-s going.md
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+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (The current state of blockchain and where it's going)
+[#]: via: (https://opensource.com/article/19/12/blockchain-evolution)
+[#]: author: (axel simon https://opensource.com/users/axel)
+
+The current state of blockchain and where it's going
+======
+Take a look at the ecosystem and the projects trying to solve some of
+the limitations of blockchain technology.
+![Arrows moving a process forward][1]
+
+In an earlier post, [_Blockchain evolution: A quick guide and why open source is at the heart of it_][2], I discussed the first generations of blockchains: the public Bitcoin and cryptocurrency blockchains, followed by the Ethereum blockchain capable of executing programs ("smart contracts"), leading to permissioned versions of code-executing blockchains (e.g., Hyperledger Fabric, Quorum).
+
+Let's step back into the blockchain jungle and take a look at the current state of the ecosystem and the projects trying to solve some of the limitations of blockchain technology: speed and throughput, cross-blockchain information and value exchange, governance, and identity and account management.
+
+### Speeding things up
+
+One of the oft-heard gripes about current blockchain technologies is their limited speed, often measured by the number of transactions per second (TPS) that they can manage. This issue strongly limits their use in systems that need to process massive amounts of events. For instance, it has often been said (correctly) that Bitcoin can't handle more than seven transactions per second, and Ethereum can't do much more. Possibly the simplest way of defining the next generation of blockchains is with novel ways to try to solve the scalability problems that current generations of blockchains constantly battle. (Permissionless ones especially. I will return to what separates permissionless and permissioned chains below.)
+
+The most obvious option—and one of the most fiercely debated one in the Bitcoin community—is "simply" to make the blocks of transactions bigger so that they can handle more transactions per block, and thus per second. Opposing interests in Bitcoin have made this solution very hard to implement (a clear problem with the "governance by code" model I mentioned in my previous article, which I will return to in a future article), but it nonetheless remains a relatively straightforward option for blockchain projects in general. Increasing the frequency at which blocks are created is another one.
+
+I also mentioned another way to handle more transactions per second in the first article: changing the constraints of the problem. Going from a permissionless network—one that anyone can join and participate in—to a permissioned one—where joining requires permission—changes the constraints and offers the option of reconsidering the security requirements. When you know everyone in a consortium—and have legal ties to them—you can choose to use consensus mechanisms, which don't assume everything should be verified at all times and thus speed things up. Furthermore, permissioned blockchain frameworks, such as Hyperledger Fabric, will typically offer the option to choose the number of transactions contained in a block and their frequency. Whether it's the number of transactions per block or the number of blocks generated that increases, the end result will be an increase in TPS.
+
+This is how permissioned systems can reach tens of thousands of TPS, numbers far beyond the major permissionless networks. It is also unsurprising, then, that Facebook's recently announced Libra cryptocurrency plans to use a permissioned model (although its "blockchainness" is debated) to handle a high number of transactions, in line with its stated goals.
+
+### Holding out for consensus
+
+However, private, permissioned ledgers will not be suited to all use cases. There need to be improvements in general to permissionless networks' capacity to manage more events at a time. This leads us to where the most ambitious work might be happening: consensus mechanisms.
+
+Getting all participants to come to a consensus on the "truth" of all the transactions (i.e., the changes) that happen on the network and on their order is one of the great difficulties of distributed systems. As a type of distributed system, blockchains inevitably contend with it, too.
+
+Bitcoin's solution is to organize a race every 10 minutes to solve a computational puzzle and let the winner settle what transactions happened in the last time period and in which order, which everyone else can then easily verify and agree on. By virtue of the kind of puzzle used, the winner is essentially random, but the problem with this "Nakamoto-style proof of work" is that the puzzles used in this race also require horrendously high computational resources to solve (by design), and the work of everyone but the winner is thrown away after each round.
+
+While it is secure, proof of work is also energy-consuming and slow.
+
+What we need are better consensus mechanisms that will allow participants of blockchain networks to come to agreement more efficiently, making it possible for the whole system to process more events per second.
+
+Ethereum, notably, is working on numerous innovations to solve these limitations. First of all, it plans to let go of proof of work to move to a proof of stake consensus mechanism, often referred to as the [Casper protocol][3]. It uses economic incentives and disincentives to get the nodes to secure the network and make cheating (very) costly.
+
+Another problem a blockchain that can execute smart contracts must contend with is how the execution of code is guaranteed to be correct and what impact this has on the processing capacity of the overall network. Currently, Ethereum requires each validating node to execute the code to verify that the results offered by other nodes are correct. This poses scalability issues, as the greater the success of the Ethereum "world computer," the more code validators need to check: all the nodes need to agree on the order _and_ the validity of each line of code executed and will inevitably be held back by the slowest node.
+
+One of the options to alleviate this issue is [_sharding_][4], a solution where only part of the network executes the code and returns results the rest of the network can verify.
+
+Pushing this idea further, [ZEXE][5], a project by the team behind Zcash, deals with this situation by making it possible to submit the result of the execution of code along with a cryptographic proof that the result is correct. Other nodes can then take this proof and check it very quickly without redoing the computation. This, combined with bounties for proving results wrong, creates a system where code can be executed by a single node and checked by many, and it makes for a clever way of speeding up the execution of distributed applications (dapps).
+
+Consensus in distributed systems is not exactly a new research field, but as blockchains have become popular, there has been renewed interest in consensus research. I could mention many more (Tendermint, Ouroboros, and Algorand come to mind), but I'll offer one other interesting approach regarding consensus: consensus agility. For instance, Hyperledger Sawtooth can [change consensus][6] on the fly, "putting all blockchain configuration on the chain itself." This makes it possible to start a network using a given consensus mechanism and switch to a different, more adapted one when the network and its users have changed, say going from a small-scale deployment to a large consortium.
+
+This is starting to shed light on an important aspect of the evolution of blockchains: modularity. While the first projects were very tightly integrated, over time, efforts have been made to separate the different layers: networking, consensus, application, and even information storage.
+
+### Layer 2 solutions: Generation 2.5?
+
+Solutions baked directly into the blockchain—such as the ones above—are considered to be layer 1. Solutions built on top of a blockchain are called layer 2 solutions.
+
+These layer 2 solutions, such as the [Lightning Network][7] for Bitcoin or [Raiden][8] for Ethereum, are designed to speed up the overall system by offloading transactions to a secondary network. It's designed to achieve much higher throughput while still connecting to the main blockchain and maintaining its important characteristics: distributed, permissionless, and trust-minimizing. While similar to some degree to sidechains (connecting another system to the main chain, an idea I will return to in the next article), they don't use the idea of a secondary chain. Instead, they build overlay networks that rely on the underlying chain for security and accountability but can exchange information much, much faster and in a peer-to-peer manner.
+
+Layer 2 solutions are essentially built for cryptocurrencies and create payment tunnels anchored to the underlying cryptocurrency's blockchain, where the amounts exchanged between two parties are eventually settled. By taking most transactions off-chain and alleviating how much needs to happen on the main chain and offloading most transactions to the second layer, they help speed up the entire system.
+
+### Conclusion
+
+Speed is the great limiter on the potential of permissionless blockchains. There is a great deal of work going on to explore solutions to this challenge while maintaining the integrity of the chain. Recent research on consensus is leading to new approaches which offer less environmentally unfriendly guarantees on accuracy.
+
+Open source software is constantly evolving, and as an open source ecosystem, blockchains are a prime example of this reality: Many projects are experimenting with various solutions to shared problems, and these solutions are being studied, refined, and improved by the rest of the community.
+
+The next installment of this series will examine how current generations of blockchain technologies are trying not just to make individual blockchains more efficient but also capable of working together.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/blockchain-evolution
+
+作者：[axel simon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/axel
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/BUSINESS_twoforward.png?itok=exkV49ts (Arrows moving a process forward)
+[2]: https://opensource.com/article/18/6/blockchain-guide-next-generation
+[3]: https://github.com/ethereum/eth2.0-specs/tree/dev/specs/core
+[4]: https://github.com/ethereum/wiki/wiki/Sharding-FAQ
+[5]: https://eprint.iacr.org/2018/962.pdf
+[6]: https://www.hyperledger.org/blog/2017/11/22/un-pluggable-consensus-with-hyperledger-sawtooth
+[7]: https://lightning.network/
+[8]: https://raiden.network/
diff --git a/sources/talk/20191209 5G in 2020- Still just a private party.md b/sources/talk/20191209 5G in 2020- Still just a private party.md
new file mode 100644
index 0000000000..45d7b48d5f
--- /dev/null
+++ b/sources/talk/20191209 5G in 2020- Still just a private party.md
@@ -0,0 +1,77 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (5G in 2020: Still just a private party)
+[#]: via: (https://www.networkworld.com/article/3488563/5g-in-2020-still-just-a-private-party.html)
+[#]: author: (Jon Gold https://www.networkworld.com/author/Jon-Gold/)
+
+5G in 2020: Still just a private party
+======
+
+Vertigo3D / Getty Images
+
+To hear the major mobile carriers talk about it, [5G][1] is here. They’ve deployed it, it works, and it’s ready to start changing the world just about right away, with ultra-fast connectivity, low latency and a dramatically improved ability to handle huge numbers of different connections at once.
+
+Eventually, that will all be true – but, according to experts in the field, it isn’t yet, and most of it won’t take place within the coming calendar year. The 3GPP standards that will underpin all new-radio 5G technology are still not yet finalized, although that is expected to happen in early 2020, which means the much-touted 5G deployments in the U.S. are based partially on pre-standard technology.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][2]
+
+Those deployments are also, at this point, quite limited in size, confined to a few major cities, and only covering centrally located intersections and occasional landmarks. It’s worth noting, though, that the parts of the 5G standard that work over some of the same frequencies as existing LTE have been finalized.
+
+[][3]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][3]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+Babak Beheshti, a member of the IEEE’s board of directors, said that the main way 5G will make a mark in 2020 will be in private deployments. A company can use pre-standard versions of 5G to create very fast, low-latency networks within its own facilities. Vendors like Ericsson and Nokia are already getting ready to sell the requisite equipment, and a private 5G network has a number of potential upsides, thanks in part to it being based on existing carrier technology.
+
+“Because of its inherent privacy and security, in that sense, it’ll provide wireless access to employees at a much more secure level,” he said.
+
+Beheshti also noted that there are potential downsides to the use of private 5G – including cost and the fact that it will require a fairly dense deployment of access points, given its use of comparatively high-frequency radio waves.
+
+According to Forrester Research vice president Glenn O’Donnell, another potential issue is power consumption – compared to a [Wi-Fi 6][4] network of similar capacity, at least – but that’s an arguable point, and both technologies will be competitive for this type of deployment.
+
+“This is one of the many holy wars we’ve seen in technology,” he said. “You’ll get people who fall into one camp or the other – a lot of it, unfortunately, is going to come down to who’s marketing better.”
+
+Still, it seems clear that there’s a potential market there in the enterprise sector for a fast, low-latency network that’s also highly secure. O’Donnell said that the manufacturing, warehousing and logistics verticals might be particularly interested in private 5G, given the networking needs created by IoT and related developments and a lesser incidence of highly sophisticated Wi-Fi implementations.
+
+Beheshti concurred, saying that a relatively green field makes the most sense for private 5G deployment.
+
+“Given the expenditure involved, where it would really provide most ROI is for companies that have no private wireless or very little private wireless setup or infrastructure,” he said.
+
+Widespread carrier-based implementation of 5G technology, however, is unlikely to happen over the course of 2020, and a big part of the reason why is that the devices on the market that are compatible with 5G networks are slim to non-existent.
+
+According to O’Donnell, software-defined 5G radios are present on some of the latest Samsung phones and a few handsets made in China, and they’re likely capable of being reconfigured with OTA updates to mesh with any final standard for the millimeter-wave technology that provides 5G’s most impressive connection speeds. Yet that’s not a guarantee.
+
+“If a new band opened up that nobody foresaw as a possibility, that could cause hiccups,” he said.
+
+It’s easy to understand the reason behind all the hype. The mobile carriers are eager to tout their cutting-edge technology, and full-fledged 5G will be an undeniably impressive achievement. It will enable a huge range of new wireless applications, and improve overall connectivity for just about every user. But the fact remains that it’s not going to do all that in 2020, and, beyond the limited use case for private implementations of the technology, 5G isn’t something that enterprise users will need to concern themselves with too heavily in the coming year.
+
+“I fully believe 5G is going to be transformative, but it needs to be built out,” said O’Donnell. “This is going to take time and a lot of money.”
+
+Join the Network World communities on [Facebook][5] and [LinkedIn][6] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3488563/5g-in-2020-still-just-a-private-party.html
+
+作者：[Jon Gold][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Jon-Gold/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3203489/what-is-5g-how-is-it-better-than-4g.html
+[2]: https://www.networkworld.com/newsletters/signup.html
+[3]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[4]: https://www.networkworld.com/article/3356838/how-to-determine-if-wi-fi-6-is-right-for-you.html
+[5]: https://www.facebook.com/NetworkWorld/
+[6]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191209 Data centers in 2020- Automation, cheaper memory.md b/sources/talk/20191209 Data centers in 2020- Automation, cheaper memory.md
new file mode 100644
index 0000000000..fdea7c35c8
--- /dev/null
+++ b/sources/talk/20191209 Data centers in 2020- Automation, cheaper memory.md
@@ -0,0 +1,132 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Data centers in 2020: Automation, cheaper memory)
+[#]: via: (https://www.networkworld.com/article/3487684/data-centers-in-2020-automation-cheaper-memory.html)
+[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
+
+Data centers in 2020: Automation, cheaper memory
+======
+As data centers grow in 2020, enterprises will refine the balance between on-premises and cloud resources, adopt AI on servers and try to manage data sprawl effectively.
+[Arthur Ogleznev / Unsplash][1] [(CC0)][2]
+
+It’s that time of year again when those of us in the press make our annual prognostications for the coming year. Some things we saw coming; the rise of the cloud and the advance of SSD. Others, like the return of many cloud migrations to on-premises or the roaring comeback of AMD, went right by us. We do our best but occasionally there are surprises.
+
+So with that, let’s take a peek into the always cloudy (no pun intended) crystal ball and make 10 data-center-oriented predictions.
+
+### IoT spawns data-center growth in urban areas
+
+This isn’t a hard prediction to make since it’s already happening. For the longest time, [data centers][3] were placed in the middle of nowhere near renewable energy (usually hydro), but need is going to force more expansion in major metro areas. [IoT][3] will be one driver but so will the increasing use of data center providers like Equinix and DRT as interconnection providers.
+
+[][4]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][4]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+### Rise of network accelerators
+
+Big Data and artificial intelligence of all flavors mean enormous amounts of data, and not all of it can be found in one place. Add to it that for now, CPUs are required to power network traffic controllers, thus taking them away from their main job of crunching data.
+
+So you will see more and more network accelerators coming to market like Mellanox’s [ConnectX line][5] to let CPUs do the job of processing data and accelerators do the job of moving around massive amounts of data faster than is done now.
+
+### NVMe over fabrics grows
+
+Non-volatile memory express ([NVMe][6]) is a storage interface, like serial advanced technology attachment (SATA). The downside of SATA is that its legacy is in hard disks so it fails to take full advantage of the speed and parallelism of [SSD][7]s. But early enterprise SSDs had a problem: They could only talk to the physical server in which they were installed. Either that or a server needed storage arrays, which meant network hops, which meant latency.
+
+NVMe over fabrics ([NVMeoF][8]) is an important advance. It lets an SSD in one server communicate over the network to another drive somewhere else on the network. This direct communication will be vital for improved data movement in enterprise computing and digital transformation.
+
+ * [Backup vs. archive: Why it’s important to know the difference][9]
+ * [How to pick an off-site data-backup method][10]
+ * [Tape vs. disk storage: Why isn’t tape dead yet?][11]
+ * [The correct levels of backup save time, bandwidth, space][12]
+
+
+
+### Cheaper storage-class memory
+
+Storage-class memory is memory that goes in a DRAM slot and can function like DRAM but can also function like an SSD. It has near-DRAM-like speed but has storage capabilities, too, effectively turning it into a cache for SSD.
+
+Intel and Micron were working on SCM together but parted company. Intel released its SCM product, [Optane][13], in May, and Micron came to market in October with QuantX. South Korean memory giant SK Hynix is also working on a SCM product that’s different from the 3D XPoint technology Micron and Intel use as well.
+
+All of this should do wonders to advance the technology and hopefully bring the price down. Right now a 512GB stick of Optane runs an insane $8,000. Granted, Xeons sell for even more than that, but after a while it becomes prohibitively expensive to assemble a fully decked-out server. Advancement of the technology and competition should lower prices, which will make this class of memory more attractive to enterprises.
+
+### AI automation on brand-name servers
+
+All of the server vendors are adding AI to their systems but Oracle is really taking the lead with its autonomous everything, from the hardware through OS and application and middleware stack. HPE, Dell, and Lenovo will continue to make their own advances as well but the hyperscale-server vendors like Inspur and Supermicro will lag because they have only the hardware stack and have done next to nothing in the OS space. They also are lagging in storage, something the big-three server vendors excel at.
+
+Oracle may not be a top-five server vendor, but no one can ignore what they are doing in the automation space. Expect the other brand name-vendors to provide their own increasing levels of automation.
+
+### Cloud migrations slow
+
+Remember when everyone was looking forward to shutting down their data centers entirely and moving to the cloud? So much for that idea. IDC’s latest CloudPulse survey suggests that 85% of enterprises plan to move workload from public to private environments over the next year. And a recent survey by Nutanix found 73% of respondents reported that they are moving some applications off the public cloud and back on-prem. Security was cited as the primary reason.
+
+And since it’s doubtful security will ever be good enough for some companies and some data, it seems the mad rush to the cloud will likely slow a little as people become more picky about what they put in the cloud and what they keep behind their firewall.
+
+### Data sprawl, Part 1
+
+Most data is not where it should be, according to IDC. Only 10% of corporate data is “hot” – data that is repeatedly accessed and used – while 30% is “warm ” – used semi-regularly – and the other 60% belongs in cold storage where it is rarely if ever accessed.
+
+But the problem is that data is scattered all over the place and often in the wrong tier. Many storage firms have focused on deduplication but not on storage tiers. A startup called Spectra Logic is targeting that very problem, and I suspect it won’t be the last firm to make such an effort. If it really takes off, I expect HPE and Dell to lock horns over the company, too.
+
+### Data sprawl, Part 2
+
+IDC [predicts][14] the total global data haul to weigh in at 175 zettabytes by 2025, and we are already at 32ZB of data, much of it useless. There was a time when data warehousing ruled that data was sorted and processed and stored as something useful. Now people fill data lakes with an endless supply of data from a growing number of sources, like social media and IoT.
+
+Sooner or later, something will have to give. People will take a look at petabytes of data-lake junk and say enough is enough and start to become considerably more picky about what they store. They will question the rationale behind spending a fortune on hard disks and storage arrays to store vast quantities of unused and valueless data. The pendulum will swing back to the data-warehouse model of keeping usable data. It has to or people will be overwhelmed.
+
+### More servers with a mix of processors
+
+Ten years ago, it didn’t matter if your definition of a server was a single-socket Xeon tower sitting under a desk or four-socket rack-mount in a seven-foot cabinet, they were defined by an x86 processor. But now we are seeing more server designs with on-board GPUs, Arm processors, AI accelerators, and network accelerators.
+
+This will require some changes in server designs. First, liquid cooling will become more necessary with this multitude of chips running faster and hotter and in an enclosed space. Second, the software stack will need to be more robust to handle all these chips, requiring some work on the part of Microsoft and the Linux distros.
+
+### IT workload will change
+
+Don’t think that automation means you can sit around playing games on your iPhone. Thanks to their ever-evolving systems, IT pros will have a bunch of new headaches including:
+
+ * Combating shadow IT
+ * Addressing digital transformation
+ * Developing AI strategies to keep up with competitors
+ * Reacting appropriately to the fallout from new AI strategies
+ * Maintaining security governance across the company
+ * Handling an increasing inflow of data and figuring out what to do with it
+ * Responding faster than ever to customers and to company reputation on social media
+
+
+
+Join the Network World communities on [Facebook][15] and [LinkedIn][16] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3487684/data-centers-in-2020-automation-cheaper-memory.html
+
+作者：[Andy Patrizio][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Andy-Patrizio/
+[b]: https://github.com/lujun9972
+[1]: https://unsplash.com/photos/rWDumHFt8E8
+[2]: https://creativecommons.org/publicdomain/zero/1.0/
+[3]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
+[4]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[5]: https://www.networkworld.com/article/3433924/mellanox-introduces-smartnics-to-eliminate-network-load-on-cpus.html
+[6]: https://www.networkworld.com/article/3280991/what-is-nvme-and-how-is-it-changing-enterprise-storage.html
+[7]: https://www.networkworld.com/article/3326058/what-is-an-ssd.html
+[8]: https://www.networkworld.com/article/3394296/nvme-over-fabrics-creates-data-center-storage-disruption.html
+[9]: https://www.networkworld.com/article/3285652/storage/backup-vs-archive-why-its-important-to-know-the-difference.html
+[10]: https://www.networkworld.com/article/3328488/backup-systems-and-services/how-to-pick-an-off-site-data-backup-method.html
+[11]: https://www.networkworld.com/article/3315156/storage/tape-vs-disk-storage-why-isnt-tape-dead-yet.html
+[12]: https://www.networkworld.com/article/3302804/storage/the-correct-levels-of-backup-save-time-bandwidth-space.html
+[13]: https://www.networkworld.com/article/3279271/intel-launches-optane-the-go-between-for-memory-and-storage.html
+[14]: https://www.networkworld.com/article/3325397/idc-expect-175-zettabytes-of-data-worldwide-by-2025.html
+[15]: https://www.facebook.com/NetworkWorld/
+[16]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191209 Google Cloud bare-metal initiative targets migrating legacy apps from on-prem.md b/sources/talk/20191209 Google Cloud bare-metal initiative targets migrating legacy apps from on-prem.md
new file mode 100644
index 0000000000..bb87e12189
--- /dev/null
+++ b/sources/talk/20191209 Google Cloud bare-metal initiative targets migrating legacy apps from on-prem.md
@@ -0,0 +1,87 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Google Cloud bare-metal initiative targets migrating legacy apps from on-prem)
+[#]: via: (https://www.networkworld.com/article/3487626/google-cloud-bare-metal-initiative-targets-migrating-legacy-apps-from-on-prem.html)
+[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
+
+Google Cloud bare-metal initiative targets migrating legacy apps from on-prem
+======
+Google Cloud now offers Google Bare Metal Solution, a service that supplies hardware in the cloud for enterprises that want full control of the entire stack from operating system on up to their most important legacy apps.
+Google
+
+In the cloud-services market, [bare metal offerings][1] have lagged behind virtualized ones, mostly because the use of the cloud for things like elastic apps and developer environments are better suited to instances with a native operating system.
+
+The term “bare metal” simply means no software of any kind, not even a [hypervisor][2]. Customers provide their own operating environments, and the provider offers nothing more than CPUs, memory, and storage. Up to now, IBM has led the charge with bare-metal services because SoftLayer, the major data-center provider it acquired in 2014, was heavily involved in that business.
+
+Now Google Cloud is going after that market, especially targeting “lift and shift” of an entire operating environment – OS, hypervisor, apps, and data -- from on-premises data centers to the cloud.
+
+[][3]
+
+BrandPost Sponsored by HPE
+
+[HPE Synergy For Dummies][3]
+
+Here’s how IT can provide an anytime, anywhere, any workload infrastructure.
+
+Google [recently announced][4] the Google Bare Metal Solution for legacy applications that must run on dedicated hardware and have strict hardware certification requirements, as well as dedicated, low-latency and highly resilient interconnects, and connections to all native Google Cloud services.
+
+Bare Metal Solution uses OEM hardware that is certified for many ISV software applications as well as custom-built applications, with Oracle Database the one commercial software product specifically named. The hardware is a bit of a mystery, since Google, like most hyperscale data-center operators, uses off-brand hardware from Gigabyte, Inspur, and Supermicro, but it’s usually hardware from HPE, Dell, and Lenovo that gets those kinds of certifications. Not that the white-box brands don’t have it, but it’s usually not as much of a priority for them.
+
+These hardware configurations are offered as a subscription, billed monthly with a preferred term length of 36 months, which means they want you to stick around a while. There are no data ingress and egress charges between Bare Metal Solution and Google Cloud in the same region, however for now, Bare Metal Solutions are only available in East Coast data centers.
+
+Moving an Oracle database to the cloud isn’t trivial. If the database stretches into the petabytes, that could get very expensive. Not to mention Oracle is doing its darnedest to keep that business by making it easier for customers to migrate their databases into Oracle’s cloud infrastructure.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][5]
+
+Storage comes in 1TB increments, either a mix of HDD and SSD or all-flash. As for the rest of the configurations:
+
+Dual-socket x86 systems
+
+ * 16 core with 384 GB DRAM
+ * 24 core with 768 GB DRAM
+ * 56 core with 1536 GB DRAM
+
+
+
+Quad-socket x86 systems
+
+ * 56 core with 1536 GB DRAM
+ * 112 core with 3072 GB DRAM
+
+
+
+Other benefits of the service are:
+
+ * End-to-end infrastructure management such as compute, storage and networking, as well as fully managed and monitored environments such as power, cooling and facilities.
+ * Support for infrastructure, including defined SLAs for initial response; 24X7 coverage for all Priority 1 and 2 issues; unified billing across Google Cloud and Bare Metal Solution.
+ * Enterprise-grade SLAs for hardware uptime and interconnect availability.
+
+
+
+Bare metal has its appeal but caveats, too. The allure of the cloud is its bursty elasticity. Many on-prem apps are used to running all out for much if not all of the day. In a cloud setting that can get expensive in a hurry, so it’s up to IT staff to decide if it’s a good idea to migrate an Oracle database to the cloud. If it's serving up reads and writes constantly, any savings from moving it off premises will be immediately offset by paying to run it at high utilization in the cloud.
+
+Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3487626/google-cloud-bare-metal-initiative-targets-migrating-legacy-apps-from-on-prem.html
+
+作者：[Andy Patrizio][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Andy-Patrizio/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3261113/why-a-bare-metal-cloud-provider-might-be-just-what-you-need.html
+[2]: https://www.networkworld.com/article/3243262/what-is-a-hypervisor.html
+[3]: https://www.networkworld.com/article/3399618/hpe-synergy-for-dummies.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE19718&utm_content=sidebar (HPE Synergy For Dummies)
+[4]: https://cloud.google.com/blog/products/gcp/bare-metal-solution-enabling-specialized-workloads-in-google-cloud
+[5]: https://www.networkworld.com/newsletters/signup.html
+[6]: https://www.facebook.com/NetworkWorld/
+[7]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191209 LibreCorps mentors humanitarian startups on how to run the open source way.md b/sources/talk/20191209 LibreCorps mentors humanitarian startups on how to run the open source way.md
new file mode 100644
index 0000000000..3d3674e7db
--- /dev/null
+++ b/sources/talk/20191209 LibreCorps mentors humanitarian startups on how to run the open source way.md
@@ -0,0 +1,103 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (LibreCorps mentors humanitarian startups on how to run the open source way)
+[#]: via: (https://opensource.com/article/19/12/humanitarian-startups-open-source)
+[#]: author: (Justin W. Flory https://opensource.com/users/jflory)
+
+LibreCorps mentors humanitarian startups on how to run the open source way
+======
+NGOs and nonprofits can increase their reach by building open source
+communities.
+![Two diverse hands holding a globe][1]
+
+Free and open source software are no longer workplace taboos, at least not in the same way they were fifteen years ago. Today, distributed collaboration platforms and tools empower people around the world to contribute code, documentation, design, leadership, and other skills to open source projects. But do newcomers actually have a deep understanding of free and open source software?
+
+If you hang around in open source communities for long enough, you realize there is more to open source than slapping a free software license on a project and throwing it over an imaginary fence to wait for contributors who never come. To address this problem in the humanitarian sector, the LibreCorps program, led by Rochester Institute of Technology's FOSS initiative at the [Center for Media, Arts, Interaction & Creativity][2] (MAGIC,) partnered with UNICEF to develop a set of resources to help new open source maintainers chart an "open source roadmap" to build a community.
+
+![Grassroots presentation in UNICEF office ][3]
+
+### What is LibreCorps?
+
+[LibreCorps][4] connects RIT students interested in open source to humanitarian and civic coding opportunities; specifically, opportunities for co-operative education placements (co-ops,) which are full-time paid internships included in the university's graduation requirements.
+
+LibreCorps students work in two major areas on co-ops. The first, not surprisingly, is technology. The second is FOSS community and processes. Many NGOs and civic organizations put openly licensed work in repositories but need a plan to build and maintain a community of contributors around their technology.
+
+LibreCorps has worked with numerous humanitarian projects over the years. Recently, LibreCorps was contracted by [UNICEF Innovation][5] to support the [Innovation Fund][6] by mentoring several cohorts of international start-ups in adopting best practices to meet the open source requirement of their funding.
+
+Periodically, the UNICEF Innovation Fund invites the companies together for cohort workshops, with hands-on mentorship a primary component of the workshop. [Stephen Jacobs][7] and [Justin W. Flory][8] represented LibreCorps at [two UNICEF Innovation Fund workshops][9] to help these teams better understand free and open source, as well as how to successfully build communities and teams that operate as [open organizatio][10][ns][10]. Most of these teams have either never worked in open source projects or only have a basic understanding of licenses and GitHub. Often, for these teams, working on your code in a way where anyone can see what you are doing is a radical shift in process.
+
+UNICEF Innovation has engaged with open source for years and currently provides funded teams with a course on [open source business models][11].
+
+> "We'd approached open-source pretty tentatively and definitely naively. We were keen to move to open source for transparency and perception but, beyond that, had no plans around deriving or creating value, and we were nervous about the perceived risks. The mentorship from Mike Nolan has given us clear direction and a deeper understanding that open source isn't a compromise but a communication channel and a way to build a community, and he's giving us the tools that enable that." — Michael Nunan, Director at Tupaia.
+
+### How do we create workable community strategy guides?
+
+This past summer, LibreCorps began developing and evolving resources to help these teams take the complex and difficult challenge of building an open source community and break it down into smaller, more manageable steps. [Mike Nolan][12] and [Kent Reese][13] developed a roadmap template for teams to evaluate their current status in maintainership best practices and chart out milestones for where to go next. For a cohort working in open source for the first time, the LibreCorps team offers advice and suggestions on crafting a mission statement, choosing the right license for your project, and more. The rubrics provide an interactive, color-coded reference to unlock a deeper understanding of their progress towards each milestone.
+
+Let's explore each resource in more detail to understand how they work:
+
+### Roadmap template
+
+The [roadmap template][14] is a resource that gets hands-on and personal to a specific open source project. There are five tracks within the roadmaps with different tasks to gradually ramp up the areas of focus for community management.
+
+The first track includes milestones like writing a mission statement, choosing a free software license, and establishing a code of conduct, and provides a set of open source tools or frameworks for users to learn more about. The second track includes gradually more advanced milestones like documenting how to set up a development environment, learning the pull request workflow, choosing a project hosting platform, and more. Further tracks include milestones like implementing continuous integration (CI,) organizing community events, and gathering user testimonials.
+
+The LibreCorps team works with each Innovation Fund team within the cohort to create a rubric specific to their projects. The cohort identifies their current position based on which milestone they are currently working toward. Then, we work together to determine next steps for growing their open source community, then create a strategy to reach and accomplish those goals.
+
+### Self-evaluation rubric
+
+The milestone template provides high-level guidance on which direction to go, but the [self-evaluation rubric][15] is a feedback mechanism to give cohorts a picture of exceptional, acceptable, and poor implementations for each assigned task. The self-evaluation rubrics enable LibreCorps cohorts to independently self-evaluate progress towards building a sustainable and open community.
+
+The rubric is organized into five tracks:
+
+ * Community outreach
+ * Continuous integration and health checks
+ * Documentation
+ * Project management
+ * Workflow
+
+
+
+Each track includes detailed sets of sub-tasks or specific components of building an open source community. For example, documentation includes writing guidelines for how to contribute, and community outreach includes maintaining a project website and engaging with an upstream project community, if one exists.
+
+The LibreCorps team mostly works with the rubric to evaluate whether Innovation Fund cohort teams sufficiently meet the open source requirement for their project. Some teams make use of the rubric to get a more detailed understanding of whether they are heading in the right direction with their community work.
+
+### Contribute to these resources
+
+Do these resources sound useful or interesting? Fortunately, the LibreCorps content is licensed under Creative Commons licenses. Learn more about LibreCorps on the [FOSS@MAGIC website][4] and keep up with what we are doing on [our GitHub][16]. To get in touch with us, visit our community Discourse forums on [fossrit.community][17].
+
+A few months ago, we profiled open source projects working to make the world a better place. In...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/humanitarian-startups-open-source
+
+作者：[Justin W. Flory][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/jflory
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/world_hands_diversity.png?itok=zm4EDxgE (Two diverse hands holding a globe)
+[2]: https://www.rit.edu/magic/
+[3]: https://opensource.com/sites/default/files/uploads/unicef-flory_0.jpg (Grassroots presentation in UNICEF office )
+[4]: https://fossrit.github.io/librecorps/
+[5]: https://www.wired.com/story/wired25-stories-people-racing-to-save-us/
+[6]: https://unicefinnovationfund.org/
+[7]: https://www.rit.edu/magic/affiliate-spotlight-stephen-jacobs
+[8]: https://justinwflory.com/
+[9]: https://fossrit.github.io/announcements/2019/04/01/unicef-foss-community-building/
+[10]: https://opensource.com/open-organization/resources/open-org-maturity-model
+[11]: https://www.google.com/url?q=https://agora.unicef.org/course/info.php?id%3D18096&sa=D&ust=1573658770972000&usg=AFQjCNGemgWoJ3kCoKImLCDok7opIo2RCA
+[12]: https://nolski.rocks/
+[13]: https://kentr.itch.io/
+[14]: https://docs.google.com/document/d/1M2nVwh7ArjAU31M7QZWP4AQz1cOyMhw90iP8Wg9lZNo/edit?usp=sharing
+[15]: https://docs.google.com/spreadsheets/d/11DaQxbiOv9_EiZEozEkUapf2AsVQ4vBFelhnZ0a8R4w/edit?usp=sharing
+[16]: https://github.com/librecorps/
+[17]: https://fossrit.community/
diff --git a/sources/talk/20191210 Italian job- Translating our mission statement in the open.md b/sources/talk/20191210 Italian job- Translating our mission statement in the open.md
new file mode 100644
index 0000000000..4ef0c383ff
--- /dev/null
+++ b/sources/talk/20191210 Italian job- Translating our mission statement in the open.md
@@ -0,0 +1,106 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Italian job: Translating our mission statement in the open)
+[#]: via: (https://opensource.com/open-organization/19/12/translating-mission-statement)
+[#]: author: (Antonella Iecle https://opensource.com/users/aiecle)
+
+Italian job: Translating our mission statement in the open
+======
+A seemingly straightforward translation exercise turned into a lesson
+about the power of open decision making.
+![Yellow arrows going both ways with texture][1]
+
+At Red Hat, part of my job is to ensure that company messages maintain their meaning and effectiveness in my native language—Italian—so that customers in my region can learn not only about our products and services but also about [our organizational values][2].
+
+The work tends to be simple and straightforward. But in an open organization, even the tasks that seem small can present big opportunities for learning about the power of working the open way.
+
+That was the case for me recently, when what I thought would be a quick translation exercise turned into a lesson in the [benefits of open decision making][3].
+
+### A crowdsourced decision
+
+A few months ago, I noticed a post on our company's internal collaboration platform that seemed to be calling my name. Colleagues from around the world were leaving comments on translated versions of one particular (and very important) corporate message: the [company's mission statement][4]. And they had questions about the Italian translation.
+
+So I joined the conversation with no hesitation, assuming I'd engage in a quick exchange of opinions and reach a conclusion about the best way to translate Red Hat's mission statement:
+
+_To be the catalyst in communities of customers, contributors, and partners creating better technology the open source way._
+
+That's a single sentence consisting of less than 20 words. Translating it into another language should be a no-brainer, right? If anything, the work should take no longer than a few minutes: Read it out loud, spot room for improvement, swap a word for a more effective synonym, maybe rephrase a bit, and you're done!
+
+As a matter of fact, that's not always the case.
+
+Translations of the mission statement in a few languages were already available, but comments from colleagues reflected a need for some review. And as more Red Hatters from different parts of the globe joined the discussion and shared their perspectives, I began to see many possibilities for solving this translation problem—and the challenges that come with this abundance of ideas.
+
+Seeing so many inspiring comments can make reaching a decision much more complicated. One might put concepts into words in a _number_ of ways, but how do we all agree on the _best_ way? How do we deliver a message that reflects our common goal? How do we make sure that all employees can identify with it? And how do we ensure that our customers understand how we can help them grow?
+
+It's true: When you're about to make a decision that has an impact on other people, you have to ask yourself—and each other—a lot of questions.
+
+It's true: When you're about to make a decision that has an impact on other people, you have to ask yourself—and each other—a lot of questions.
+
+### Found in translation
+
+Localising a message for our readers around the world means more than just translating it word by word. A literal translation may not be fully understandable, especially when the original message was written with English native speakers in mind. On the other hand, a creative translation may be just one of many possible interpretations of the original text. And then there are personal preferences: Which translation sounds better to me? Is there a particular reason? If so, how do I get my point across?
+
+Linguistic debates can highlight complex aspects of communication, from the subtle nuances in the meaning of a particular word to the cultural traits, mindsets, and levels of familiarity with a topic that define how the same message can be perceived by readers from different countries. Our own conversations delved into known linguistic dilemmas like the use of anglicisms and the disambiguation of expressions that can have more than one interpretation.
+
+Localisation teams must ensure that messages are delivered accurately and consistently. Working collaboratively is essential to achieving this goal.
+
+To get started, we only had to look at how our original mission statement had come together in the first place. Since we were trying to do something that someone else had done before, we needed to ask: "[How did Red Hat find its mission][5]?"
+
+The answer? By asking the whole company what it should be.
+
+Opening up the conversation doesn't always accelerate the decision making process.
+
+It may be counterintuitive, but engaging the broader community can be a very efficient way to overcome uncertainties and address problems you weren't even aware of. Opening up the conversation doesn't always accelerate the decision making process, but by bringing people together you allow them to draw a clearer picture of the problem and provide you with the elements you need to make better decisions.
+
+With that in mind, all you have to do is ask other teams to contribute, then give them a reasonable amount of time to make room in their busy schedule and think about how they can help. Suggestions will come, and how you will channel the incoming information is up to you.
+
+Surveys are often a great way to gather feedback and keep track of incoming responses, and this is the approach we chose. We submitted a new translation, and asked our teams in Italy to tell us if they were happy with it. The majority of the respondents were. However, a few participants had their own versions to share (and valid comments to add).
+
+After considering everyone's input, we submitted a second survey. We asked the participants to choose between the solution we offered in the first survey and a _newer_ version, one we obtained by incorporating the feedback we'd received from our recent collaborative discussion.
+
+The second option was the winner.
+
+The initial translation did not represent Red Hat's mission as clearly and faithfully as the improved statement did. For example, in the original version, Red Hat was a “point of reference” rather than a "catalyst," and worked with "a community" rather than a larger and more diverse number of "communities." We were using the word "collaborators" instead of "contributors," and our actions were following a set of "principles" rather than the open source "way."
+
+The changes we made reaffirmed Red Hat's role in the communities and its commitment to open source technology, but also to open source as a way of working.
+
+Don't be afraid to jump into a conversation—or even to take the lead—if you think you can help to make better decisions.
+
+So here is some advice this experience taught me: Don't be afraid to jump into a conversation—or even to take the lead—if you think you can help to make better decisions. Because as Jim Whitehurst likes to say, in the open source world, we believe [the best ideas should win][6], no matter where they come from.
+
+In short, here is my five-point checklist for open decision-making, regardless of the task you face:
+
+ 1. Encourage wide participation.
+ 2. Welcome all responses as they arrive.
+ 3. Identify the best ideas and get the most out of everyone's suggestions.
+ 4. Answer questions and address concerns.
+ 5. Communicate the outcome, and summarize the steps of the decision process. In doing so, reassert the value of broad collaboration.
+
+
+
+One more thing (I know I said I only had five more points, but don't switch off yet): Keep listening to what people might have to say about the decision you just made together.
+
+The best ideas may take longer to brew.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/open-organization/19/12/translating-mission-statement
+
+作者：[Antonella Iecle][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/aiecle
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/arrows_translation_lead.jpg?itok=S4vAh9CP (Yellow arrows going both ways with texture)
+[2]: https://www.redhat.com/en/book-of-red-hat#our-values
+[3]: https://opensource.com/open-organization/resources/open-decision-framework
+[4]: https://www.redhat.com/en/book-of-red-hat#our-vision-intro
+[5]: https://www.managementexchange.com/blog/how-red-hat-used-open-source-way-develop-company-mission
+[6]: https://opensource.com/open-organization/16/8/how-make-meritocracy-work
diff --git a/sources/talk/20191211 Passive optical LAN- Its day is dawning.md b/sources/talk/20191211 Passive optical LAN- Its day is dawning.md
new file mode 100644
index 0000000000..4250c357af
--- /dev/null
+++ b/sources/talk/20191211 Passive optical LAN- Its day is dawning.md
@@ -0,0 +1,91 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Passive optical LAN: Its day is dawning)
+[#]: via: (https://www.networkworld.com/article/3489477/passive-optical-lan-its-day-is-dawning.html)
+[#]: author: (Zeus Kerravala https://www.networkworld.com/author/Zeus-Kerravala/)
+
+Passive optical LAN: Its day is dawning
+======
+
+Getty Images
+
+The concept of using passive optical LANs in enterprise campuses has been around for years, but hasn’t taken off because most businesses consider all-fiber networks to be overkill for their needs. I’ve followed this market for the better part of two decades, and now I believe we’re on the cusp of seeing POL go mainstream, starting in certain verticals.
+
+The primary driver of change from copper to optical is that the demands on the network have evolved. Every company now considers its network to be business critical where just a few years ago, it was considered best effort in nature. Downtime or a congested network meant inconvenienced users, but today they mean the business is likely losing big money.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][1]
+
+There are also a number of new trends driving the evolution of the campus network. These include:
+
+[][2]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][2]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+ * Cloud services. The cloud is certainly the way of the future but it’s playing havoc with enterprise networks. As data centers evolved to modernized systems, East-West traffic was superseded by North-South. Today, businesses are connecting direct to cloud for [hybrid-cloud][3] deployments driving more North-South traffic. Traditional networks can be a bottleneck.
+ * [Internet of Things][4] (IoT). [Wi-Fi 6 and 5G][5] will enable more devices to be connected in more places leading to more bandwidth on the network. For the first time in history, wireless speeds will match wired speeds straining the campus network.
+ * Video of all kinds is on the rise. Surveillance, collaboration, room systems, streaming and other kinds of video usage are on the rise. Video requires high-quality, low-latency connectivity.
+
+
+
+### Copper is running out of life
+
+The increased speeds pose quite a predicament for companies. If the organization has Cat5 cabling, the speed is capped at 1Gbps. If Cat6 is deployed, speeds of 10Gbps can be reached but only 55 meter’s distance. If the company wants to reach the full 100M length of copper, Cat6A or higher must be used. Optical cable has no distance limitations because POL is completely passive and requires no electronics to boost the signal. Optical cabling can carry petabytes of bandwidth over long distances. Also, with optical, there’s no concern over what type of cable is being used and having the quality degrade over time. Lastly, upgrading speeds is easier. The cabling can stay in place and just the optics get changed out at the ends of the cable making the process simple.
+
+### POL is a cheaper, longer lasting than copper upgrades
+
+If businesses are faced with having to upgrade their networks from Cat5 to another type of cabling, it might make sense to look at POL as it can be the foundation for the campus network for years.
+
+The early adopters of POL are companies that are highly distributed with large campuses and need to get more network services in more places. This includes manufacturing organizations, universities, hospitality, cities and airports. Although I’ve highlighted a few verticals, the fact is that any business can take advantage of POL.
+
+### POL in a mixed-use development
+
+At a Huawei conference earlier this year the company showcased the Dubai Creek Harbor project being built by Emaar Properties – a six-square-mile development including residences, offices, retail and cultural facilities. The complex is designed to be fully digital and the network has to support IoT, cloud computing, AI-based analytics and more.
+
+The project features an optical network built on Huawei’s Campus OptiX solution that simplifies the network as the architecture moves from a three-tier hierarchical design to a two-tier one. That design uses less equipment and reduces power and cooling requirements. Also, the flat, 10Gbps network obviates the need for parallel overlay networks, making it easier to manage and giving it a degree of future-proofing as the network can easily be upgraded. The all-optical network resulted in a 60% improvement in operational efficiency and a deployment time that was cut in half compared a similar network using Ethernet.
+
+### Cost effective **
+
+**
+
+Although there are many benefits to POL, adoption has been light. The biggest impediment to its adoption is a general lack of awareness and a misunderstanding of cost. The actual cost of fiber cabling is higher than copper, but I’ve talked to many companies that have looked at fully loaded costs and often optical is cheaper. Optical isn’t subject to electromagnetic interference like copper is so there’s no need to lay a pipeline down first. Also, copper cabling requires distribution cabinets to boost the signal and that adds the cost of UPSes, cooling and power that fiber does not.
+
+North American buyers may not have the same awareness of POL as those in China, where:
+
+ * The engineering standard of POL was released in June, outlining the system, design, cabling, testing and acceptance rules.
+ * An alliance was established Oct. 22 bringing together a number of companies including Nokia, Huawei, and Yangtze Optical Fiber and Cable.
+
+
+
+Both of these will help drive innovation and standardization.
+
+Copper has been the preferred campus backbone, but businesses are changing and so is the network. It’s not enough to just change the infrastructure but the cabling that connects everything should be looked at and POL used as a next-generation backbone.
+
+Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489477/passive-optical-lan-its-day-is-dawning.html
+
+作者：[Zeus Kerravala][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Zeus-Kerravala/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/newsletters/signup.html
+[2]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[3]: https://www.networkworld.com/article/3268448/what-is-hybrid-cloud-really-and-whats-the-best-strategy.html
+[4]: https://www.networkworld.com/article/3207535/what-is-iot-how-the-internet-of-things-works.html
+[5]: https://www.networkworld.com/article/3402316/when-to-use-5g-when-to-use-wi-fi-6.html
+[6]: https://www.facebook.com/NetworkWorld/
+[7]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191211 Passive optical networking- Its day is dawning.md b/sources/talk/20191211 Passive optical networking- Its day is dawning.md
new file mode 100644
index 0000000000..c8e61f2c4c
--- /dev/null
+++ b/sources/talk/20191211 Passive optical networking- Its day is dawning.md
@@ -0,0 +1,91 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Passive optical networking: Its day is dawning)
+[#]: via: (https://www.networkworld.com/article/3489477/passive-optical-networking-its-day-is-dawning.html)
+[#]: author: (Zeus Kerravala https://www.networkworld.com/author/Zeus-Kerravala/)
+
+Passive optical networking: Its day is dawning
+======
+
+Getty Images
+
+The concept of using passive optical LANs in enterprise campuses has been around for years, but hasn’t taken off because most businesses consider all-fiber networks to be overkill for their needs. I’ve followed this market for the better part of two decades, and now I believe we’re on the cusp of seeing POL go mainstream, starting in certain verticals.
+
+The primary driver of change from copper to optical is that the demands on the network have evolved. Every company now considers its network to be business critical where just a few years ago, it was considered best effort in nature. Downtime or a congested network meant inconvenienced users, but today they mean the business is likely losing big money.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][1]
+
+There are also a number of new trends driving the evolution of the campus network. These include:
+
+[][2]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][2]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+ * Cloud services. The cloud is certainly the way of the future but it’s playing havoc with enterprise networks. As data centers evolved to modernized systems, East-West traffic was superseded by North-South. Today, businesses are connecting direct to cloud for [hybrid-cloud][3] deployments driving more North-South traffic. Traditional networks can be a bottleneck.
+ * [Internet of Things][4] (IoT). [Wi-Fi 6 and 5G][5] will enable more devices to be connected in more places leading to more bandwidth on the network. For the first time in history, wireless speeds will match wired speeds straining the campus network.
+ * Video of all kinds is on the rise. Surveillance, collaboration, room systems, streaming and other kinds of video usage are on the rise. Video requires high-quality, low-latency connectivity.
+
+
+
+### Copper is running out of life
+
+The increased speeds pose quite a predicament for companies. If the organization has Cat5 cabling, the speed is capped at 1Gbps. If Cat6 is deployed, speeds of 10Gbps can be reached but only 55 meter’s distance. If the company wants to reach the full 100M length of copper, Cat6A or higher must be used. Optical cable has no distance limitations because POL is completely passive and requires no electronics to boost the signal. Optical cabling can carry petabytes of bandwidth over long distances. Also, with optical, there’s no concern over what type of cable is being used and having the quality degrade over time. Lastly, upgrading speeds is easier. The cabling can stay in place and just the optics get changed out at the ends of the cable making the process simple.
+
+### POL is a cheaper, longer lasting than copper upgrades
+
+If businesses are faced with having to upgrade their networks from Cat5 to another type of cabling, it might make sense to look at POL as it can be the foundation for the campus network for years.
+
+The early adopters of POL are companies that are highly distributed with large campuses and need to get more network services in more places. This includes manufacturing organizations, universities, hospitality, cities and airports. Although I’ve highlighted a few verticals, the fact is that any business can take advantage of POL.
+
+### POL in a mixed-use development
+
+At a Huawei conference earlier this year the company showcased the Dubai Creek Harbor project being built by Emaar Properties – a six-square-mile development including residences, offices, retail and cultural facilities. The complex is designed to be fully digital and the network has to support IoT, cloud computing, AI-based analytics and more.
+
+The project features an optical network built on Huawei’s Campus OptiX solution that simplifies the network as the architecture moves from a three-tier hierarchical design to a two-tier one. That design uses less equipment and reduces power and cooling requirements. Also, the flat, 10Gbps network obviates the need for parallel overlay networks, making it easier to manage and giving it a degree of future-proofing as the network can easily be upgraded. The all-optical network resulted in a 60% improvement in operational efficiency and a deployment time that was cut in half compared a similar network using Ethernet.
+
+### Cost effective **
+
+**
+
+Although there are many benefits to POL, adoption has been light. The biggest impediment to its adoption is a general lack of awareness and a misunderstanding of cost. The actual cost of fiber cabling is higher than copper, but I’ve talked to many companies that have looked at fully loaded costs and often optical is cheaper. Optical isn’t subject to electromagnetic interference like copper is so there’s no need to lay a pipeline down first. Also, copper cabling requires distribution cabinets to boost the signal and that adds the cost of UPSes, cooling and power that fiber does not.
+
+North American buyers may not have the same awareness of POL as those in China, where:
+
+ * The engineering standard of POL was released in June, outlining the system, design, cabling, testing and acceptance rules.
+ * An alliance was established Oct. 22 bringing together a number of companies including Nokia, Huawei, and Yangtze Optical Fiber and Cable.
+
+
+
+Both of these will help drive innovation and standardization.
+
+Copper has been the preferred campus backbone, but businesses are changing and so is the network. It’s not enough to just change the infrastructure but the cabling that connects everything should be looked at and POL used as a next-generation backbone.
+
+Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489477/passive-optical-networking-its-day-is-dawning.html
+
+作者：[Zeus Kerravala][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Zeus-Kerravala/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/newsletters/signup.html
+[2]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[3]: https://www.networkworld.com/article/3268448/what-is-hybrid-cloud-really-and-whats-the-best-strategy.html
+[4]: https://www.networkworld.com/article/3207535/what-is-iot-how-the-internet-of-things-works.html
+[5]: https://www.networkworld.com/article/3402316/when-to-use-5g-when-to-use-wi-fi-6.html
+[6]: https://www.facebook.com/NetworkWorld/
+[7]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191212 Companies Prefer Hybrid Cloud to Escape Public Cloud Data Grabbity.md b/sources/talk/20191212 Companies Prefer Hybrid Cloud to Escape Public Cloud Data Grabbity.md
new file mode 100644
index 0000000000..3b58213cf7
--- /dev/null
+++ b/sources/talk/20191212 Companies Prefer Hybrid Cloud to Escape Public Cloud Data Grabbity.md
@@ -0,0 +1,59 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Companies Prefer Hybrid Cloud to Escape Public Cloud Data Grabbity)
+[#]: via: (https://www.linux.com/articles/companies-prefer-hybrid-cloud-to-escape-public-cloud-data-grabbity/)
+[#]: author: (Swapnil Bhartiya https://www.linux.com/author/swapnil/)
+
+Companies Prefer Hybrid Cloud to Escape Public Cloud Data Grabbity
+======
+
+[![][1]][2]
+
+[![][1]][2]
+
+As the cloud native space is maturing, customers have started to discern the pros and cons of public cloud. They can see not just the facade of convenience and promised cost savings, but also the bills piling up and having to hand over critical business data to public cloud companies.
+
+[Red Hat recently conducted a global customer survey][3] about this and results indicate that customers prefer hybrid cloud over public cloud. More than 31% respondents actually used the term hybrid cloud as their cloud strategy.
+
+Rob Hirschfeld, founder and CEO of RackN and attendee of the recent [Gartner IT Infrastructure, Operations & Cloud Strategies Conference][4], noticed a similar tone. “Discussions and data from the Gartner IO Summit support that hybrid is preferred. There’s just so much existing infrastructure that it’s not practical to be ‘pure’ anything! It’s not so much that they want hybrid but that it’s the reality they are facing.”
+
+There are many reasons why customers prefer hybrid over public cloud or pure private cloud. Red Hat says it boils down to three factors: data security, cost benefits, and data integration.
+
+“Everyone accepts that cloud is secure; however, operators are starting to question how well they can control their data in cloud. Also, some of them don’t trust the cloud vendors, especially with some of the new analytics services,” said Hirschfeld.
+
+Hybrid cloud enables customers to balance all three factors highlighted in the Red Hat survey. They can move pieces of their infrastructure between public and private cloud depending on the need. It lets them reap the benefits of public cloud without having to compromise their data.
+
+Although 31% might seem like a small number, it doesn’t mean that the remaining 69% is running their workloads on public cloud. In fact, only 12% described themselves as having either a public cloud first strategy or a strategy to standardize on a single public cloud. Red Hat says 6% described their strategy as multi-cloud based on multiple public clouds, while 21% have a private cloud first strategy.
+
+In particular, EMEA respondents described themselves as having a private cloud strategy, not hybrid. This region is concerned about handing over their data to US-based cloud companies, given its current political landscape. A simple embargo on your country will cut your entire business out of the public cloud run by Google, AWS, and Azure. Some of the biggest use cases in this region involve companies building their own private and public cloud using OpenStack.
+
+Perhaps the most worrisome finding is that there are still companies without any concrete cloud strategy. Around 17% of the respondents were still working on a plan, while 12% respondents didn’t have any plan at all. Unfortunately, these companies are so far behind the curve that their future hangs in the balance. Hirschfeld warns that there is an urgency to cut their technical debt and embrace cloud now or they will find it hard to survive in the modern world.
+
+In fact, Hirschfeld states that you need to have a cloud strategy even if you don’t use cloud. “The reality is that cloud is the default deployment choice for everything — from demos and proof-of-concept to training — because it’s predictable and accessible.” Teams must adapt to the patterns, even if they are not adopting.
+
+The Red Hat survey found that companies do recognize the importance of building up technical skills. When asked to choose their top non-IT funding priorities, respondents chose both technical skills training (16%) and a digital transformation strategy (16%).
+
+However, new technologies and jargon are emerging at such a fast pace that it’s virtually impossible to find experts (or even skilled professionals) in technologies that were open-sourced at CNCF just a month ago. The hype/adoption curve is so accelerated that it has gotten silly. Therefore, porting to the latest shiny requires evaluation.
+
+“The reality is that new projects, even Kubernetes, still need baking time for scale operations. If there are not enough people with knowledge, then it’s OK (really, it’s required) to pick your battles or slow your adoption,” said Hirschfeld.
+
+--------------------------------------------------------------------------------
+
+via: https://www.linux.com/articles/companies-prefer-hybrid-cloud-to-escape-public-cloud-data-grabbity/
+
+作者：[Swapnil Bhartiya][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.linux.com/author/swapnil/
+[b]: https://github.com/lujun9972
+[1]: https://www.linux.com/wp-content/uploads/2019/12/computer-2930704_1280-1068x634.jpg (computer-2930704_1280)
+[2]: https://www.linux.com/wp-content/uploads/2019/12/computer-2930704_1280.jpg
+[3]: https://www.redhat.com/en/blog/red-hat-global-customer-tech-outlook-2020-hybrid-cloud-leads-strategy-aiml-leaps-forefront
+[4]: https://www.gartner.com/en/conferences/na/infrastructure-operations-cloud-us
diff --git a/sources/talk/20191212 Liquid cooling and edge computing are featured at Gartner show.md b/sources/talk/20191212 Liquid cooling and edge computing are featured at Gartner show.md
new file mode 100644
index 0000000000..26d95b835c
--- /dev/null
+++ b/sources/talk/20191212 Liquid cooling and edge computing are featured at Gartner show.md
@@ -0,0 +1,69 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Liquid cooling and edge computing are featured at Gartner show)
+[#]: via: (https://www.networkworld.com/article/3489467/liquid-cooling-and-edge-computing-are-featured-at-gartner-show.html)
+[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
+
+Liquid cooling and edge computing are featured at Gartner show
+======
+Non-traditional hardware makes the news at Gartner’s show focused on data-center operations.
+ExaScaler
+
+Research firm Gartner is holding its IT Infrastructure, Operations, and Cloud Strategies Conference (IOCS) in Las Vegas this week, and a few news announcements from the show give an indication as to where [data-center][1] technology is headed.
+
+First up, Schneider Electric and Iceotope formally introduced their integrated rack with chassis-based immersive liquid-cooling designs. The deal was [announced][2] in October but now the details are out. In addition to Schneider and Iceotope, the alliance also includes Avnet, an electronic-component distributor.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][3]
+
+The server is optimized for compute-intensive applications such as analytics and artificial intelligence. It combines a high-powered GPU server with Iceotope’s liquid-cooling technology, while Avnet integrates the server with Schneider’s NetShelter liquid-cooled enclosure system for simple deployment into data centers or edge-computing environments.
+
+[][4]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][4]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+This is a big advance because most immersion solutions have been using a bathtub design where the motherboard sat vertically in the immersion fluid and the ports stuck out at the top. It was something of a clumsy design that just begged for spillage. Here, the chassis looks like any other rack-mounted server, but it is enclosed and sealed.
+
+The system is certified EcoStruxure Ready, meaning it works with Schneider’s enclosures, and comes with next-generation data center management software EcoStruxure IT Expert and digital service EcoStruxure Asset Advisor.
+
+“This latest development marks a significant step toward industrializing chassis-based immersion solutions which offer the efficiency and effectiveness of tank-based solutions while providing the compatibility and serviceability of more traditional, ‘direct-to-chip’ liquid-cooling designs. Given the growth of compute-intensive applications, we believe this approach is very promising,” said Kevin Brown, CTO and senior vice president of innovation, secure power at Schneider Electric in a statement.
+
+### Scale Computing: Tiny edge device
+
+Scale Computing introduced the HE150 at the show, the latest addition to its HC3 Edge product line intended for space-constrained and edge customers.
+
+The HE150 is a very small device based on the [Intel NUC][5] design, and Scale notes it is about the size of three smartphones, with a width and depth of just over 11 centimeters and a height of just over three centimeters.
+
+The HE150 appliance is a small, all-flash, [NVMe][6] storage-based compute appliance that supports disaster recovery, high availability clustering, rolling upgrades and integrated data protection. As it is, Scale sells them in three-node clusters.
+
+Scale also announced it plans to make its HC3 Edge software for Intel NUC-based systems from other hardware suppliers. HC3 Edge software will be available soon for Lenovo’s new Smart Edge portfolio of fan-less, small-form-factor PCs.
+
+Join the Network World communities on [Facebook][7] and [LinkedIn][8] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489467/liquid-cooling-and-edge-computing-are-featured-at-gartner-show.html
+
+作者：[Andy Patrizio][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Andy-Patrizio/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
+[2]: https://www.networkworld.com/article/3444624/schneider-electric-launches-wall-mounted-server-rack.html
+[3]: https://www.networkworld.com/newsletters/signup.html
+[4]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[5]: https://www.intel.com/content/www/us/en/products/boards-kits/nuc.html
+[6]: https://www.networkworld.com/article/3280991/what-is-nvme-and-how-is-it-changing-enterprise-storage.html
+[7]: https://www.facebook.com/NetworkWorld/
+[8]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191212 Secure SD-WAN- The security vendors and their SD-WAN offerings.md b/sources/talk/20191212 Secure SD-WAN- The security vendors and their SD-WAN offerings.md
new file mode 100644
index 0000000000..9d3e799da4
--- /dev/null
+++ b/sources/talk/20191212 Secure SD-WAN- The security vendors and their SD-WAN offerings.md
@@ -0,0 +1,136 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Secure SD-WAN: The security vendors and their SD-WAN offerings)
+[#]: via: (https://www.networkworld.com/article/3489480/secure-sd-wan-the-security-vendors-and-their-sd-wan-offerings.html)
+[#]: author: (Matt Conran https://www.networkworld.com/author/Matt-Conran/)
+
+Secure SD-WAN: The security vendors and their SD-WAN offerings
+======
+A networking vendor simply can’t jump into this space. Some SD-WANs add stateful packet filters and call this security.
+[Gerd Altmann][1] [(CC0)][2]
+
+During its inception, we had the early adopters and pure SD-WAN players. Soon it became obvious that something was missing, and that missing component was “security.” However, security vendors have highlighted the importance of security from the very beginning.
+
+Today, the market seems to be moving in the direction where the security vendors are focusing on delivering SD-WAN features around pervasive security. The Magic Quadrant for WAN Edge Infrastructure has made a substantial prediction. It states, “By 2024, 50% of new firewall purchases in distributed enterprises will utilize SD-WAN features with the growing adoption of cloud-based services, up from less than 20% today.”
+
+Nowadays we have security vendors like Forcepoint, SonicWall and Barracuda that follow the pattern of Fortinet. The vendors offer a built-in security stack to the WAN edge architecture for distributed enterprise use cases.
+
+[][3]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][3]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+### Introducing secure SD-WAN
+
+Pronouncedly, secure SD-WAN includes the best-of-breed next-generation firewall security, SD-WAN, advanced routing, and WAN optimization to deliver a security-driven WAN edge. It combines the SD-WAN feature and security features together.
+
+The secure SD-WAN solution can be placed fully in the branch and the cloud or a hybrid approach can be adopted. For those who don’t want to put everything in the cloud, a hybrid approach could be more viable.
+
+To me, it is quite interesting seeing how the queries are coming into the analysts and how customers are giving attention to this field. Markedly, Gartner estimates that Fortinet has more than 21,000 WAN edge customers. That’s a considerable user base and makes a compelling case, especially when strong and built-in security capabilities are the key requirements.
+
+### Adding security to networking
+
+It is definitely easier for a security company to add new networking features than for an SD-WAN company to add 20 years of advanced security features. We can safely assume that no SD-WAN vendor is going to become a security vendor.
+
+**[ Now read [20 hot jobs ambitious IT pros should shoot for][4]. ]**
+
+As the market developed, in due course, some features had to be renamed: when we talk about application identification, encryption, path monitoring, routing protocols and WAN link load balancing. Fundamentally, all of these advanced routing features are not new and specific to SD-WAN. These are not overnight successes and have been in the market even before the market existed.
+
+However, in some scenarios, maybe you have to implement a proprietary routing protocol across the WAN. In this case, yes, of course, you require a new device. But for most of the part, a comprehensive firewall at the edge will suffice.
+
+### The firewall at the WAN edge
+
+Firewalls are evolving into network security platforms, thereby offering SD-WAN capabilities. The Magic Quadrant for Network Firewalls states “The SMB multifunction firewall market grew 10.1% in 2018, with SD-WAN adoption being a strong driver.”
+
+When you think about it, you will realize that the firewall has been acting as a router for a long time. Essentially, the firewall can provide all the routing protocols to facilitate private WAN, internet and internal routing. This functionality is usually provided by a basic device that just does the routing. However, now we are witnessing the replacement of these by an edge appliance with firewalls.
+
+Firewalls have resided in the networks for decades. Their role has not just been confined to doing the firewalling but also participating in the routed networks. Time and again, they have been providing a routed WAN edge device.
+
+### Issues with legacy security design
+
+How do you integrate security with SD-WAN? Primarily, the common design involves the integration of multiple security point solutions. Now, let’s learn about the aftermath of these point solutions.
+
+### Complexity
+
+The point solution only addresses one issue and requires a considerable amount of integration with others. Because of this, they are often service-chained together. Each part must be carefully integrated with the other.
+
+You must continuously add solutions to the stack, which is likely to result in management overhead and increased complexity. Not to mention the challenges with NOC and SOC team integration. Contrarily, the original selling point for SD-WAN was to reduce complexity and not intensify it.
+
+If we examine security in the world of SD-WAN; the way it has been geared up at the moment is provided in parts that actually increase complexity. It’s like building a house with individual pieces when you actually just want to buy a house.
+
+If you analyze, you will find that many SD-WANs are merely bringing in security technologies from other vendors, joined together to sell them to the customers.
+
+### Associated costs
+
+Having multiple point solutions often from different vendors dispersed around the network is expensive. There’s never a fixed price. Some security vendors may charge on usage models which you may not have the quantity for yet. So, how do you effectively plan for this when you have multiples?
+
+As the costs keep adding up, the security professionals may decide to trade-off certain point solutions due to the associated costs. We know now this is not an effective risk management strategy. Ideally, in terms of security, you don't do something when it is needed; you do it before it is needed. This means threat intelligence is the key, which is often overlooked by many SD-WAN vendors.
+
+It’s far more critical from both technical and cost perspective to bring each of the security point solution functionalities together under one hood. And to do this, someone that specializes in security from day one would fit the bill. This is why there has been a move to provide SD-WAN features along with advanced security into one comprehensive integrated platform.
+
+Secure SD-WAN is what combines both network and security into one integrated platform. This leads to no more complex management, licensing issues, high costs or unnecessary service chaining.
+
+### SD-WAN is not about features
+
+There is a lot of noise in the SD-WAN market about the features. Let’s face it ‘features really don’t draw much value to create market separation’. Practically, the value proposition for SD-WAN is not about the feature. Everyone is doing a good job in classifying applications and sending them across the best path. Let’s understand the true value proposition for SD-WAN.
+
+### Performance and scalability
+
+When it comes to SD-WAN, the bell to ring is often application steering, but if you don’t have, for example, the deep TLS1.3 inspection with solid performance, how can you get accurate identification and make sure your branch is secure? Not enough people are talking about this.
+
+For this, we need custom SD-WAN-specific application-specific integrated circuits (ASICs). This offers an incredible advantage for the high resource intensive encryption/decryption and overlay scalability.
+
+With IPSec, there are intensive encrypting operations that consume a lot of CPU and RAM. Therefore, a purpose-built SD-WAN ASIC is built just to do that so it consumes less CPU and RAM per tunnel.
+
+In general, the scalability stops at 1,000 or 1,500. With the proper ASIC, this number can be scaled to over 100,000, which may be useful for some hub site designs. By using the ASIC, you can run the networking stack and security stack in the same appliance, making a very efficient and cost-effective solution.
+
+### The importance of threat intelligence
+
+The next-generation firewall is in the datasheets for many SD-WAN vendors. However, what about the threat detection and threat prevention? A big piece missing from the many SD-WAN vendors is threat intelligence in alliance with threat research. The threat landscape is evolving, so too should the security solution to keep in line with today’s and tomorrow's threats.
+
+Threat prevention has core features from layer 4 to layer 7 such as IPS, content filtering, deep SSL inspection, and anti-malware. Furthermore, we also have a threat detection piece. Nowadays, you can no longer rely on detecting known threats, you have to detect unknown threats too. So having a stack of both prevention and detection features is very important. With the two features glued together, we can have experienced security research and analyst teams. It is significant to observe whether the SD-WAN vendor has its own threat intelligence.
+
+For this, we really do need the security company pedigree. The core value for any security vendor comes with their level of intelligence research. This is what creates market separation, not SD-WAN features.
+
+However, there is another step, which is to confirm if the proposed features have been validated by 3rd parties such as NSS labs. NSS Labs has evaluated some of these security vendors for their SD-WAN leading products on areas such as the quality of experience (QoE) of VoIP and video, performance (WAN impairments and HA), the total cost of ownership (TCO) along with security effectiveness.
+
+Also, we must question how often does the ‘SD-WAN device providing firewalling’ gets updated with the latest threat information. Is this process carried a few times per day or per week? Some SD-WAN solutions market them as a secure SD-WAN vendor, but if we go back to the point of building effective security, we need a solid threat intelligence team. Do startups have enough manpower to do that? A networking vendor simply can’t jump into this space. Some SD-WANs add stateful packet filters and call this security.
+
+Let’s be honest, a next-generation firewall can be used by anyone. However, the importance of the breadth of the features, the intelligence they provide and the recognition in the market play a huge role. This is what builds trust in the next-generation firewall in the branch and ensures that the best security posture remains the best.
+
+When you’re looking for secure SD-WAN vendors, highlight these questions and examine how old their security stack is. Also, assess if they have an experienced threat intelligence team.
+
+The market is moving towards a secure SD-WAN solution. The industry analysis and the rise of the customer base have a great impact in today’s time. It is not the case that people are recognizing security vendors as strong SD-WAN players.
+
+However, recognizing the market demands secure SD-WAN in one integrated comprehensive platform.
+
+**This article is published as part of the IDG Contributor Network. [Want to Join?][5]**
+
+Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489480/secure-sd-wan-the-security-vendors-and-their-sd-wan-offerings.html
+
+作者：[Matt Conran][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Matt-Conran/
+[b]: https://github.com/lujun9972
+[1]: https://pixabay.com/illustrations/network-control-block-chain-hexagon-4478145/
+[2]: https://creativecommons.org/publicdomain/zero/1.0/
+[3]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[4]: https://www.networkworld.com/article/3276025/careers/20-hot-jobs-ambitious-it-pros-should-shoot-for.html
+[5]: https://www.networkworld.com/contributor-network/signup.html
+[6]: https://www.facebook.com/NetworkWorld/
+[7]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191213 Space-data-as-a-service gets going.md b/sources/talk/20191213 Space-data-as-a-service gets going.md
new file mode 100644
index 0000000000..c2c840e831
--- /dev/null
+++ b/sources/talk/20191213 Space-data-as-a-service gets going.md
@@ -0,0 +1,83 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Space-data-as-a-service gets going)
+[#]: via: (https://www.networkworld.com/article/3489484/space-data-as-a-service-gets-going.html)
+[#]: author: (Patrick Nelson https://www.networkworld.com/author/Patrick-Nelson/)
+
+Space-data-as-a-service gets going
+======
+Development of IoT services in space will require ruggedized edge computing. OrbitsEdge, a vendor has announced a deal with HPE for development.
+[REUTERS/Joe Skipper/File Photo][1]
+
+Upcoming space commercialization will require hardened edge-computing environments in a small footprint with robust links back to Earth, says vendor [OrbitsEdge][2], which recently announced that it had started collaborating with Hewlett Packard Enterprise on computing-in-orbit solutions.
+
+OrbitsEdge says it’s the first to provide a commercial [data-center][3] environment for installing in orbit, and will be using HPE’s Edgeline Converged Edge System in a hardened, satellite [micro-data-center][4] platform that it’s selling called SatFrame.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][5]
+
+The idea is “to run analytics such as artificial intelligence (AI) on the vast amounts of data that will be created as space is commercialized,” says Barbara Stinnett, CEO of OrbitsEdge, in a [press release][6].
+
+[][7]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][7]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+### Why data in space?
+
+[IoT][8] data collection along with analysis and experimental testing are two examples of space industrialization that the company gives as use cases for its micro-data center product. However, commercial use of space also includes imagery, communications, weather forecasting and navigation. Space tourism and commercial recovery of space resources, such as mined raw materials from asteroids are likely to be future space-uses, too.
+
+Also, manufacturing – taking advantage of vacuums and zero-gravity environments – is among the economic activities that could take advantage of number crunching in orbit.
+
+Additionally, [Cloud Constellation Corp., a company I wrote about in 2017, unrelated to OrbitsEdge or HPE, reckons highly sensitive data should be stored isolated][9] [in][9] [space][9]. That would be the “ultimate air-gap security,” it describes its [SpaceBelt][10] product.
+
+### Why edge in space?
+
+OrbitsEdge believes that data must be processed where it is collected, in space, in order to reduce transmission bottlenecks as streams are piped back to Earth stations. “Due to the new wave of low-cost commercial space activity, the bottleneck will get worse,” the company explains on its website.
+
+What it means is that getting satellites into space is now cheap and is getting cheaper (due primarily to reusable rocket technology), but that there’s a problem getting the information back to traditional cloud environments on the surface of the Earth; there’s not enough backhaul data capacity, and that increases processing costs. Therefore, the cloud needs to move to the data-collection point: It’s “IoT above the cloud,” ObitsEdge cleverly taglines.
+
+### How it works
+
+Satellite-mounted solar arrays collect power from the sun. They fill batteries to be used when the satellite is in the shadow of Earth.
+
+Cooling- and radiation-shielding protect a standard 5U, 19-inch server rack. There’s a separate rack for the avionics. Then integrated, traditional space-to-space, and space-to-ground radio communications handle the comms. Future-proofing is also considered: laser data pipes, too, could be supported, the company says.
+
+#### On Earth option
+
+Interestingly, the company is also pitching its no-maintenance, low Earth orbit (LEO)-geared product as being suitable for terrestrial extreme environments, too. OrbitsEdge claims that SatFrame is robust enough for extreme chemical and temperature environments on Earth. Upselling, it also says that one could combine two micro-data centers: a LEO SatFrame running HPE’s Edgeline, communicating with another one in an extreme on-Earth location—one at the Poles, maybe.
+
+“To keep up with the rate of change and the number of satellites being launched into low Earth orbit, new services have to be made available,” OrbitsEdge says. “Shipping data back to terrestrial clouds is impractical, however today it is the only choice,” it says.
+
+Join the Network World communities on [Facebook][11] and [LinkedIn][12] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489484/space-data-as-a-service-gets-going.html
+
+作者：[Patrick Nelson][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Patrick-Nelson/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3489484/Reuters
+[2]: https://orbitsedge.com/
+[3]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
+[4]: https://www.networkworld.com/article/3445382/10-hot-micro-data-center-startups-to-watch.html
+[5]: https://www.networkworld.com/newsletters/signup.html
+[6]: https://orbitsedge.com/press-releases/f/orbitsedge-oem-agreement-with-hewlett-packard-enterprise
+[7]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[8]: https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html
+[9]: https://www.networkworld.com/article/3200242/data-should-be-stored-data-in-space-firm-says.html
+[10]: http://spacebelt.com/
+[11]: https://www.facebook.com/NetworkWorld/
+[12]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191213 Space-data-as-a-service prepares to take off.md b/sources/talk/20191213 Space-data-as-a-service prepares to take off.md
new file mode 100644
index 0000000000..a78abf7976
--- /dev/null
+++ b/sources/talk/20191213 Space-data-as-a-service prepares to take off.md
@@ -0,0 +1,82 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Space-data-as-a-service prepares to take off)
+[#]: via: (https://www.networkworld.com/article/3489484/space-data-as-a-service-prepares-to-take-off.html)
+[#]: author: (Patrick Nelson https://www.networkworld.com/author/Patrick-Nelson/)
+
+Space-data-as-a-service prepares to take off
+======
+Development of IoT services in space will require ruggedized edge computing. OrbitsEdge, a vendor has announced a deal with HPE for development.
+REUTERS/Joe Skipper/File Photo
+
+Upcoming space commercialization will require hardened edge-computing environments in a small footprint with robust links back to Earth, says vendor [OrbitsEdge][1], which recently announced that it had started collaborating with Hewlett Packard Enterprise on computing-in-orbit solutions.
+
+OrbitsEdge says it’s the first to provide a commercial [data-center][2] environment for installing in orbit, and will be using HPE’s Edgeline Converged Edge System in a hardened, satellite [micro-data-center][3] platform that it’s selling called SatFrame.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][4]
+
+The idea is “to run analytics such as artificial intelligence (AI) on the vast amounts of data that will be created as space is commercialized,” says Barbara Stinnett, CEO of OrbitsEdge, in a [press release][5].
+
+[][6]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][6]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+### Why data in space?
+
+[IoT][7] data collection along with analysis and experimental testing are two examples of space industrialization that the company gives as use cases for its micro-data center product. However, commercial use of space also includes imagery, communications, weather forecasting and navigation. Space tourism and commercial recovery of space resources, such as mined raw materials from asteroids are likely to be future space-uses, too.
+
+Also, manufacturing – taking advantage of vacuums and zero-gravity environments – is among the economic activities that could take advantage of number crunching in orbit.
+
+Additionally, [Cloud Constellation Corp., a company I wrote about in 2017, unrelated to OrbitsEdge or HPE, reckons highly sensitive data should be stored isolated][8] [in][8] [space][8]. That would be the “ultimate air-gap security,” it describes its [SpaceBelt][9] product.
+
+### Why edge in space?
+
+OrbitsEdge believes that data must be processed where it is collected, in space, in order to reduce transmission bottlenecks as streams are piped back to Earth stations. “Due to the new wave of low-cost commercial space activity, the bottleneck will get worse,” the company explains on its website.
+
+What it means is that getting satellites into space is now cheap and is getting cheaper (due primarily to reusable rocket technology), but that there’s a problem getting the information back to traditional cloud environments on the surface of the Earth; there’s not enough backhaul data capacity, and that increases processing costs. Therefore, the cloud needs to move to the data-collection point: It’s “IoT above the cloud,” ObitsEdge cleverly taglines.
+
+### How it works
+
+Satellite-mounted solar arrays collect power from the sun. They fill batteries to be used when the satellite is in the shadow of Earth.
+
+Cooling- and radiation-shielding protect a standard 5U, 19-inch server rack. There’s a separate rack for the avionics. Then integrated, traditional space-to-space, and space-to-ground radio communications handle the comms. Future-proofing is also considered: laser data pipes, too, could be supported, the company says.
+
+#### On Earth option
+
+Interestingly, the company is also pitching its no-maintenance, low Earth orbit (LEO)-geared product as being suitable for terrestrial extreme environments, too. OrbitsEdge claims that SatFrame is robust enough for extreme chemical and temperature environments on Earth. Upselling, it also says that one could combine two micro-data centers: a LEO SatFrame running HPE’s Edgeline, communicating with another one in an extreme on-Earth location—one at the Poles, maybe.
+
+“To keep up with the rate of change and the number of satellites being launched into low Earth orbit, new services have to be made available,” OrbitsEdge says. “Shipping data back to terrestrial clouds is impractical, however today it is the only choice,” it says.
+
+Join the Network World communities on [Facebook][10] and [LinkedIn][11] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489484/space-data-as-a-service-prepares-to-take-off.html
+
+作者：[Patrick Nelson][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Patrick-Nelson/
+[b]: https://github.com/lujun9972
+[1]: https://orbitsedge.com/
+[2]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
+[3]: https://www.networkworld.com/article/3445382/10-hot-micro-data-center-startups-to-watch.html
+[4]: https://www.networkworld.com/newsletters/signup.html
+[5]: https://orbitsedge.com/press-releases/f/orbitsedge-oem-agreement-with-hewlett-packard-enterprise
+[6]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[7]: https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html
+[8]: https://www.networkworld.com/article/3200242/data-should-be-stored-data-in-space-firm-says.html
+[9]: http://spacebelt.com/
+[10]: https://www.facebook.com/NetworkWorld/
+[11]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191213 What-s hot at the edge for 2020- Everything.md b/sources/talk/20191213 What-s hot at the edge for 2020- Everything.md
new file mode 100644
index 0000000000..5f15b10d12
--- /dev/null
+++ b/sources/talk/20191213 What-s hot at the edge for 2020- Everything.md
@@ -0,0 +1,119 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (What’s hot at the edge for 2020? Everything)
+[#]: via: (https://www.networkworld.com/article/3489938/what-s-hot-at-the-edge-for-2020-everything.html)
+[#]: author: (Michael Cooney https://www.networkworld.com/author/Michael-Cooney/)
+
+What’s hot at the edge for 2020? Everything
+======
+From SD-WAN and cloud interconnection to security, the edge will be one active place in 2020
+Thinkstock
+
+Few areas of the enterprise face as much churn as the edge of the network. Experts say a variety of challenges drive this change – from increased [SD-WAN][1] access demand to cloud interconnected resources and [IoT][2], the traditional perimeter of the enterprise is shifting radically and will continue to do so throughout 2020.
+
+One indicator: Gartner research that says by 2023, more than 50% of enterprise-generated data will be created and processed outside the [data center][3] or cloud, up from less than 10% in 2019.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][4]
+
+Hand-in-hand with that change is a shift in what technologies are supported at the edge of the network – and that means information processing, content collection and delivery are placed closer to the sources, repositories and consumers of this information. Edge networking tries to keep the traffic and processing local to reduce latency, exploit the capabilities of the edge and enable greater autonomy at the edge, [Gartner says][5].
+
+[][6]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][6]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+The scope of enterprise WAN networks is broadening. No longer is it only from a branch edge to a data-center edge. Now the boundaries have shifted across the LAN from individual clients and devices on the one end and across the WAN to individual containers in data centers or clouds on the other, said Sanjay Uppal, vice president and general manager of VMware’s VeloCloud Business Unit. “This broadening of the WAN scope is a direct consequence of the democratization of data generation and the need to secure that data. So, we end up with edges at clients, servers, devices, branches, private data centers, public data centers, telco POP, RAN and the list goes on. Additionally, with IoT and mobility taking hold at the enterprise, the edge is moving out from the traditional ‘branch’ to the individual clients and devices.”
+
+“The evolution of business applications from monolithic constructs to flexible containerized workloads necessitates the evolution of the edge itself to move closer to the application data,” Uppal said. “This, in turn, requires the enterprise network to adjust and meet and exceed the requirements of the modern enterprise.”
+
+Such changes will ultimately make defining what constitutes the edge of the network more difficult.
+
+“With increased adoption of cloud-delivered services, unmanaged mobile and IoT devices, and integration of networks outside the enterprise (particularly partners), the edge is more difficult to define. Each of these paradigms extend the boundaries of today's organizations,” said Martin Kuppinger, principal analyst with [KuppingerCole Analysts A][7]G. “On the other hand, there is a common perception that there is no such perimeter anymore with statements such as “the device is the perimeter” or “identity is the new perimeter”. To some extent, all of this is true – and wrong. There still might be perimeters in defined micro-segments. But there is not that one, large perimeter anymore.”
+
+The enterprise is not the only arena that will see continued change in 2020, there are big changes afoot on the WAN was well.
+
+Analysts from [IDC wrote][8] earlier this year that traditional enterprise WANs are increasingly not meeting the needs of digital businesses, especially as it relates to supporting SaaS apps and multi- and [hybrid-cloud][9] usage. Enterprises are interested in easier management of multiple connection types across their WAN to improve application performance and end-user experience – hence the growth of SD-WAN technologies.
+
+“The market for branch-office WAN-edge functionality continues to shift from dedicated routing, security and WAN optimization appliances to feature-rich software-defined WAN and, to a lesser extent, [universal customer-premises equipment] platforms,” [Gartner wrote][10]. “SD-WAN is replacing routing and adding application-aware path selection among multiple links, centralized orchestration and native security, as well as other functions. Consequently, it includes incumbent and emerging vendors from multiple markets (namely routing, security, WAN optimization and SD-WAN), each bringing its own differentiators and limitations.”
+
+One of the biggest changes for 2020 could come around the SD-WAN. One of the drivers stems from the relationships that networking vendors such as Cisco, VMware, Juniper, Arista and others have with the likes of Amazon Web Services, Microsoft Azure, Google Anthos and IBM RedHat.
+
+An indicator of those changes came this month when AWS announced a slew of services for its cloud offering that included new integration technologies such as [AWS Transit Gateway][11], which lets customers connect their Amazon Virtual Private Clouds (VPCs) and their on-premises networks to a single gateway. Aruba, Aviatrix Cisco, Citrix Systems, Silver Peak and Versa already announced support for the technology which promises to simplify and enhance the performance of SD-WAN integration with AWS cloud resources.
+
+The ecosystem around this type of cloud interconnection is likely one of the hottest areas of growth for 2020, experts say.
+
+SD-WAN is critical for businesses adopting cloud services, acting as a connective tissue between the campus, branch, IoT, data center and cloud, said Sachin Gupta, senior vice president, product management, with Cisco Enterprise Networking in a recent [Network World][12] article. “It brings all the network domains together and delivers the outcomes business requires."
+
+"It must align user and device policies, and provide assurance to meet application service-level agreements. It must deliver robust security to every device and every cloud that the enterprise’s data touches.” The AWS Transit Gateway will let IT teams implement consistent network and data security rules, he said.
+
+All of these edge transformations will most certainly bring with it security challenges. Kuppinger noted a few including:
+
+ * Has "shadow IT" subscribed to SaaS, which now contains important business data? How is it managed?
+ * Does the IT department use IaaS for dev/test or pre-production? Is it loaded with copies of production data? How is that controlled?
+ * Does IT use IaaS and PaaS for line-of-business applications? Is it managed centrally like legacy applications?
+ * Does the enterprise allow BYOD? Are unified endpoint-management or mobile anti-malware solutions mandated for such devices?
+ * Are IoT devices on the networks? Are they outside of your networks, but delivering critical services for customers?
+ * Are third-party risks enumerated and controlled?
+
+
+
+“Each of these situations is beyond the traditional edge and can increase your enterprise attack surface and risk,” Kuppinger said. “Once identified, enterprises must figure out how to secure the edges and get more complete visibility to all risks and mitigations. New tools may be needed. Some organizations may choose to engage more managed security services,” he said.
+
+The perimeter needs to be everywhere and hence the advent of the zero-trust architecture, VMware’s Uppal said. “This requires an end-to-end view where posture is checked at the edge, and based on that assessment network traffic is segmented both to reduce the attack surface and also the blast radius. i.e., first reduce the likelihood that something is going to go wrong, but if it does then minimize the impact,” Uppal said.
+
+“As traffic traverses the network, security services, both letting through the good while blocking the bad are inserted based on policy. Here again the network of cloud services that dynamically sequences security based on business policy is critical,” Uppal said.
+
+Going forward enterprise organizations might need to focus less on the network itself. “Protect the services, protect the communication between devices and services, protect the devices and the identities of the users accessing these devices. This is very much what the “[zero trust][13]” paradigm has in mind – notably, this is not primarily “zero-trust networks”, but zero trust at all levels,” Kuppinger said.
+
+“The most important learning is: Protecting just the network at its edge is not sufficient anymore. If there is a defined network – either physical such as in OT or virtual such as in many data centers – this adds to protection,” Kuppinger said.
+
+The mixture of cloud and security services at the edge will lead to another trend in 2020, one that Gartner calls secure access service edge (SASE) which is basically the melding of network and security-as-a-service capabilities into a cloud-delivered package. By 2024, at least 40% of enterprises will have explicit strategies to adopt [SASE][14], up from less than 1% at year-end 2018, Gartner says.
+
+“SASE is in the early stages of development,” Gartner says. “Its evolution and demand are being driven by the needs of digital business transformation due to the adoption of SaaS and other cloud-based services accessed by increasingly distributed and mobile workforces, and to the adoption of edge computing.”
+
+Early manifestations of SASE are in the form of SD-WAN vendors adding network security capabilities and cloud-based security vendors offering secure web gateways, zero-trust network access and cloud-access security broker services, Gartner says.
+
+Regardless of what it’s called, it is clear the melding of cloud applications, security and new edge WAN services will be increasing in 2020.
+
+“We are seeing the rise of microservices in application development, allowing applications to be built based upon a collection of discrete technology elements. Beyond new application architectures, there are demands for new applications to support IoT initiatives and to push compute closer to the user for lower latency and better application performance,” VMware’s Uppal said. “With the maturation of Kubernetes, what is needed is the next set of application-development and -deployment tools that work cooperatively with the underlying infrastructure, compute, network and storage to serve the needs of that distributed application.”
+
+[See more predictions about what's big in IT tech for the coming year.][15]
+
+Join the Network World communities on [Facebook][16] and [LinkedIn][17] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3489938/what-s-hot-at-the-edge-for-2020-everything.html
+
+作者：[Michael Cooney][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Michael-Cooney/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3031279/sd-wan-what-it-is-and-why-you-ll-use-it-one-day.html
+[2]: https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html
+[3]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
+[4]: https://www.networkworld.com/newsletters/signup.html
+[5]: https://www.networkworld.com/article/3447397/gartner-10-infrastructure-trends-you-need-to-know.html
+[6]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[7]: https://twitter.com/kuppingercole
+[8]: https://www.idc.com/getdoc.jsp?containerId=prUS45380319
+[9]: https://www.networkworld.com/article/3268448/what-is-hybrid-cloud-really-and-whats-the-best-strategy.html
+[10]: https://www.networkworld.com/article/3489480/secure-sd-wan-the-security-vendors-and-their-sd-wan-offerings.html
+[11]: https://aws.amazon.com/transit-gateway/
+[12]: https://www.networkworld.com/article/3487831/what-s-hot-for-cisco-in-2020.html
+[13]: https://www.networkworld.com/article/3487720/the-vpn-is-dying-long-live-zero-trust.html
+[14]: https://www.networkworld.com/article/3481519/sase-redefining-the-network-and-security-architecture.html
+[15]: https://www.networkworld.com/article/3488562/whats-big-in-it-tech-for-the-coming-year.html
+[16]: https://www.facebook.com/NetworkWorld/
+[17]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191216 10 tips for onboarding open source contributors.md b/sources/talk/20191216 10 tips for onboarding open source contributors.md
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+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (10 tips for onboarding open source contributors)
+[#]: via: (https://opensource.com/article/19/12/open-source-contributors)
+[#]: author: (rowasc https://opensource.com/users/rowasc)
+
+10 tips for onboarding open source contributors
+======
+Making new contributors feel welcome in your community is essential to
+your project's future, so it's important to put time and attention into
+onboarding them.
+![Women programming][1]
+
+Contributors are the lifeblood of many open source projects because they enable smaller projects to grow and improve without a lot of financial support and they bring fresh perspectives to the project. That is the case at [Ushahidi][2], a non-profit organization that is building and using software to help raise the voices of underserved, marginalized communities. Our products enable local observers to submit reports about local humanitarian crises (such as political unrest and natural disasters) using their mobile phones or the internet, while simultaneously creating a temporal and geospatial archive of events.
+
+Ushahidi always strives for openness, but **it's very hard to evaluate how open your organization works from the inside**. Staff and longtime contributors know too much: they are cursed by knowledge and access to the people who know how things work. While a crisis brings out the good in people who want to help, getting involved with an open source project during a crisis is complex. The maintainers are usually going through a stressful time. New requests for features are coming every day. New bugs are being reported all the time.
+
+There are never enough people to fix everything, which is why it's so important for projects to have a good process for onboarding new contributors.
+
+### Why Ushahidi needed to re-engage with its community
+
+In the beginning, Ushahidi had a really big community and did a lot of community engagement. We had community dev calls, where core developers and community developers talked about what they were working on. We had t-shirts and swag; we had community badges and blog posts celebrating the top contributor of the month. We sponsored tech events and made sure to have a booth or a presentation showcasing the platform.
+
+Our documentation was good and extensive with toolkits and examples for different use cases, our forum was active, we were active!
+
+But then a few things happened. The software got outdated, and the core team started working on a new version. At the same time, we adopted a new strategy around sustainability and started a Software-as-a-Service model, spanning from free grassroots deployments to more complex enterprise plans, to try to bring much-needed financial stability and sustainability and serve new use cases and needs.
+
+All of this took longer than expected, and we did not want to bring in new contributors "just yet." Not getting our contributors engaged from the beginning resulted in our docs being unclear, unfinished, and unstructured. We did not adjust the software to be easy for our open source users to install or use. **Nothing was intentional, but we were not serving our open source community as well as we would like.** Now, our main focus is to re-engage with our community.
+
+The following are 10 things we've learned and done that may help you improve your contributor onboarding processes if you're in a similar situation.
+
+### 1\. Evaluate your processes
+
+To evaluate how open your organization's processes are and how they are working for new contributors, source new folks who can try to answer questions like: "How do you get new code into production?" and "Who can trigger a production release?" or "How does testing happen?"
+
+Some things to look for:
+
+ * Is it clear to new contributors about how to get started? Are getting-started guides hard to find, too complex, or disorganized?
+ * Are communication and coordination happening in the open? Or are they hidden in Slack rooms, making it hard to know what is going on?
+ * Is the process for code reviews and merges clear? What about the safety nets for code contributions and the QA process?
+
+
+
+When you're deep into a project with your community, it's difficult to know how it looks to new contributors. We learned that **what feels like an open process from the inside can feel very closed from the perspective of a new contributor**.
+
+### 2\. Set the foundation
+
+Diversity and inclusion are core to Ushahidi; about 80% of people working on the project are women and non-binary genders, a majority of our team are people of color, and we live on four continents. This reflects the reality that many of our users live in. They are not all in the United States, they are from diverse backgrounds, and they have different goals. What unites them is that they are all working to improve their communities in their own way.
+
+For us, **having a good foundation starts with having a diverse team that represents our users and stakeholders**. But that's not all; we have also improved our contributor resources with:
+
+ * A new developers hub
+ * New and updated documentation
+ * New pathways to contributing
+ * Videos
+ * FAQs
+
+
+
+We're also restarting our community engagement by:
+
+ * Doing webinars
+ * Hosting hackathons
+ * Proactively organizing and triaging issues
+ * Announcing releases and contributors to each release
+
+
+
+### 3\. Make "getting started" clear
+
+When someone wants to start contributing, there needs to be clarity on how to start. We label good starter contributions as first-timer issues; these describe in detail what needs to be done, how to find the code, and what you need to do. It takes us longer to write these issues than it would to fix the actual thing ourselves, but that is not the goal. The goal is to **give people who may be new to open source a chance to contribute and learn about the work we do**.
+
+#### Find the blockers
+
+It is also important to understand where the blockers for getting started are. One of Ushahidi's biggest blockers was installing the software in development environments. We assumed that because our engineers could get things set up, others would be able to do so. But other people may not have the same environment, and they absolutely did not have the amount of support that our core engineering team gets.
+
+To resolve this, we created videos on installation procedures, and we also created an **installation-helper** feature that checks common things that people forget during configuration and installation and also gives hints on how to solve problems.
+
+![Ushahidi's installation-helper][3]
+
+### 4\. Learn from diverse perspectives
+
+It's important to ask others to evaluate and double-check the documentation we provide to our contributors. We are really lucky that our team has people in programs, community, and design roles that really care about open source, and their input often helps us figure out how to **reach people who are less experienced with coding or who may want to contribute in different ways than writing code or doing QA**.
+
+When we were creating videos for our new developers hub, our community engagement officer was a big help. She is not a developer, and she is an excellent writer, so she helped by watching us go through the documentation, taking notes, then writing the initial scripts for our videos. She ensured that the things that we encounter daily—and know how to deal with by heart—are addressed in the documentation.
+
+Input like this is very valuable, since it reminds us what we know and take for granted that could confuse and turn away new contributors.
+
+### 5\. When possible, make short calls
+
+Try to invest in calls when needed and when your schedule allows. **Sometimes a five-minute call with a new contributor will give a better return than a 30-minute text chat.** If you reach a point in a chat that it's clear your instructions aren't working for the person, ask them to jump on a call to show you what they are doing. It's important to set a time limit (e.g., "I have 10 minutes now, so let's see if we can solve it right away"); otherwise, you may end up spending the whole day fixing unrelated things, which is not a great way to scale yourself.
+
+Make sure to use what you learn from these interactions to improve your documentation. Otherwise, you will find yourself doing so many 10-minute calls that you will never get anything done.
+
+### 6\. Always say thank you
+
+**Thank people even when it feels all you are getting are requests to do more work.** We say thank you for everything. We say thank you for bug reports, feature requests, for code contributions. We say thank you for reaching out and asking for help.
+
+It is hard for some people to reach out, and thanking them validates that it was OK to do so. This validation may also help people not only for the current situation but also for other projects and situations in the future.
+
+### 7\. Be kind in code reviews
+
+Someone has found you, gotten set up, fixed a bug, and finally sent a pull request. It's time to review the code. Step away from your personal opinions on how things should be. It's not time to be nit-picky and rude.
+
+When performing code reviews, **ensure you are helping the person make the code better** and not just following your personal preferences. Find at least one good thing to say about the pull request, and _always thank the contributor_.
+
+If you get a pull request that you don't plan to merge, maybe because it's the wrong scope or direction or simply something you don't want to add, it is important to deal with it straightaway instead of ignoring it. It does not help anyone to ignore pull requests, and it only serves to clutter your repository. Thank the contributor, explain why you don't plan to merge the changes, and close the pull request.
+
+If you merge the changes, make sure to tag the contributor when it goes out so that they know it had an impact.
+
+### 8\. Be responsive
+
+Throughout this process, **it is important to be responsive and not let people wait**. Giving someone some kind of response—even if you can't help them right now—and setting the expectation for when you'll be able to follow up is super-important.
+
+Sometimes a comment goes undiscovered—you miss a notification and find it three months later. It's tricky to respond in those situations, but it's still better to acknowledge the message, apologize for the delay, and ask if they still want help (with this or something else) rather than just ignoring them forever. It sets the tone that you care about your work and community, even when you make mistakes.
+
+### 9\. Help contributors thrive
+
+Sometimes a contributor comes in, sends their contributions, and leaves without much interaction. But, on some occasions, you get the opportunity to work with people over a longer time. Working with new contributors over a period of weeks or months is extremely valuable because you will gain insights into how people—especially those new to your project or tech—see your work and what challenges they face. It's also a chance to help people grow and learn. It's a win-win for everyone.
+
+In 2019, we participated in the [Google Summer of Code][4] and [Outreachy][5], and these experiences helped both the interns and our team learn new things. By working with interns, we get to understand what it's like to join our project, what onboarding looks like for a very junior engineer, and what blockers there might be to them contributing to our project.
+
+#### Prevent imposter syndrome
+
+On a related note, it's important to help prevent [impostor syndrome][6]. The feeling of not belonging or of "how did I even get here" is so common, especially among underrepresented groups in tech. It is written and talked about a lot, especially in the past tense, but rarely by people who are actively going through it.
+
+How do you spot it? How do you know someone is feeling like they aren't accomplishing enough or are feeling like a fraud?
+
+**Showing senior folks failing and learning from their mistakes helps to create an inclusive environment.** Things like pair programming, sharing your past experiences, discussing your career path, and telling people about when you made mistakes are ways to help to bridge gaps between senior engineers and new people. It helps new folks feel like they belong in tech because the smart, senior people in front of them also had concerns and made mistakes, but they picked themselves up and kept going.
+
+### 10\. Avoid communication barriers
+
+This may be obvious, but not all your contributors speak English as their first language. For many, it'll be their second, or maybe even third or fourth, language. A lot of your contributors may not speak English at a level that allows them to collaborate seamlessly, and it's important to remember that broken English is fine, even expected, in a global project. Be empathetic, be nice, and support these folks. Don't assume that someone is "dumb" just because they have bad grammar in English. Just because someone does not speak perfect English, it does not mean they aren't talented. It literally only means they don't speak perfect English.
+
+Another potential communication barrier is using mannerisms that others may perceive in different ways than we intended. For example, signing an email "Thanks, Romina" or saying "OK, bye!" sound perfectly appropriate to me, but they could signal to someone else that you don't respect them. To assign the label "rude" to someone because of this would be… quite rude?
+
+**When you are dealing with a multicultural, global network of contributors, try not to worry about language barriers or mannerisms that aren't meant to be offensive.**
+
+This doesn't mean that you should excuse bad behavior. There are no excuses for calling another person names, putting someone down, or misgendering someone on purpose, and maintainers are obligated to act on the code of conduct and resolve the situation.
+
+### In summary
+
+Making new contributors feel welcome in your community is essential to your project's future, so it's important to put time and attention into onboarding them.
+
+ * Make sure to see your community from the contributors' side.
+ * Enabling underrepresented minorities to thrive creates a more welcoming community for everyone.
+ * Be aware of the community you are serving and ask yourself what their specific needs are.
+ * Allow questions both in private and public.
+ * Be nice, set the tone.
+ * Say thank you.
+ * Be responsive.
+ * Be consistent.
+
+
+
+### Other resources
+
+ * [Ushahidi's documentation][7]
+ * [First Timers Only][8] offers good tips for first-time contributors
+ * [GitHub's all-contributors repository][9] provides specs for recognizing all types of open source contributors
+ * [Up For Grabs][10] to find open issues for OSS and how to label issues
+
+
+
+The four-day-long siege of a Nairobi mall ended Tuesday with a death toll of more than 60 people –...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/open-source-contributors
+
+作者：[rowasc][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/rowasc
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/collab-team-pair-programming-code-keyboard2.png?itok=WnKfsl-G (Women programming)
+[2]: https://www.ushahidi.com/
+[3]: https://opensource.com/sites/default/files/uploads/ushahidi_installation-helper.png (Ushahidi's installation-helper)
+[4]: https://summerofcode.withgoogle.com/archive/
+[5]: https://www.outreachy.org/
+[6]: https://opensource.com/open-organization/17/5/team-impostor-syndrome
+[7]: https://docs.ushahidi.com/index/
+[8]: https://www.firsttimersonly.com/
+[9]: https://github.com/all-contributors/all-contributors
+[10]: https://up-for-grabs.net/
diff --git a/sources/talk/20191216 7 considerations when buying network-automation tools.md b/sources/talk/20191216 7 considerations when buying network-automation tools.md
new file mode 100644
index 0000000000..cec4eed0a8
--- /dev/null
+++ b/sources/talk/20191216 7 considerations when buying network-automation tools.md
@@ -0,0 +1,93 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (7 considerations when buying network-automation tools)
+[#]: via: (https://www.networkworld.com/article/3490459/7-considerations-when-buying-network-automation-tools.html)
+[#]: author: (Zeus Kerravala https://www.networkworld.com/author/Zeus-Kerravala/)
+
+7 considerations when buying network-automation tools
+======
+Here’s the factors you need to weigh so you can make a smart decision about the network automation tool that’s best for your organization.
+bananajazz / Getty Images
+
+The concept of network automation has been around for as long as there have been networks, and until now the uptake has been slow for a number of reasons including resistance from network engineers. But now forces are coming together to create a perfect storm of sorts, driving a need for network automation tools.
+
+One factor is that more and more network teams are starting to feel the pain of working in the fast-paced digital world where doing things the old way simply does not work. The manual, box-by-box, method of configuring and updating routers and switches through a command-line interface (CLI) is too slow and error prone.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][1]
+
+Also, the rise of software-defined networks ([SDN][2]), including software-defined WANs ([SD-WAN][3]), has enabled network-automation tools to evolve from operationally focused point products that address things like change management and configuration into policy and orchestration tools.
+
+[][4]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][4]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+Today, network-automation tools are strategic, enable business alignment, and provide a roadmap to the utopian state of a fully intent-based system where the network runs and secures itself. Their time is now, but there is a wide range of them. Below are seven key criteria that enterprises should consider when deciding which is best for them.
+
+### Single vendor or multi-vendor?
+
+There are several third-party and vendor-specific network automation tools. Red Hat, NetBrain and Forward Networks are three of the leading multi-vendor tools. All of the major network vendors including Cisco, Juniper, Arista and Extreme have their own automation platforms.
+
+Customers need to determine if they want to go all in with a single vendor or strive for multiple vendors. Neither is better per se; it’s a choice the enterprise needs to make. If a single vendor platform is chosen, ensure it works with the vendor's entire product line and not just a subset. If a third-party tool is chosen, seek out one that that supports the current and likely future vendors whose gear will be in the organization’s network.
+
+### Breadth of APIs
+
+It’s important that network-automation tools interface with other tools such as ServiceNow and Splunk. This means every feature should be available as an API, which isn’t always the case. Even if a tool is being used standalone today, it will likely need to interface with another application in the near future for broader automation capabilities, so this should not be overlooked.
+
+### Orchestration
+
+When network devices change, it’s often the case that another element of the infrastructure must also change. For example, when a network device is added, it may require changing a [firewall][5] setting or connecting to a load balancer. This drives up the need for orchestration capabilities so the network-automation tool can trigger other automation frameworks to change devices that are upstream or downstream from it.
+
+### AI/intent-based networking capabilities
+
+The concept of an [intent-based network][6] is that it runs, heals and secures itself. This can’t be done with a bevy of rules because the environment changes too fast. Instead, AI capabilities should be included in the system to fully automate all operations so the network itself can adapt to changes.
+
+ZK Research recommends that the system have two modes of operation – one that recommends changes for the engineer to execute on and then one that fully executes changes without requiring human intervention. This will let the customer get comfortable with AI first. (One question ZK Research gets a lot is how one knows it’s really AI based. The answer is that the tool gets smarter over time. All changes should feed back into the system as part of the learning data set and make the system smarter. Rules-based systems will not.)
+
+### SaaS or on-prem?
+
+Traditional network-automation tools have been offered only as on-premises software or appliances. There is a growing number of companies that prefer to buy the tools in a software as a service (SaaS) model to ensure rapid deployment and continuous updates.
+
+Again, there’s no wrong choice. The company needs to determine which option best fits its operating model and compliance requirements.
+
+One important note: It’s the belief of ZK Research that all solutions will eventually be hybrid where customers may keep the data on the local premises, but advanced, artificial intelligence capabilities and cross-company comparisons will be done in the cloud. On-prem solutions do not have the necessary horsepower to deliver real-time AI capabilities
+
+### Compliance and security reporting
+
+There’s a growing push from leading organizations to bring IT and security operations together. This means network-automation tools need to provide information that shows security policies are continually being adhered to and compliance mandates are being met. The reporting capabilities need to provide visibility into every phase of the network lifecycle including planning, deploying and optimization.
+
+### Ease of use
+
+This is an often-overlooked component of management platforms. Feature-rich tools with long learning curves can require years before IT teams realize their full value. Also, when a product is too technical, the company is put at risk if people with the best knowledge of it exit the organization.
+
+Network automation tools should be fully GUI based, which means every feature available via the CLI should also be accessible through the graphical interface. The tools should be easy to use as well so lower level engineers can work with it. This will obviate the need to always include a senior, more expensive engineer.
+
+Join the Network World communities on [Facebook][7] and [LinkedIn][8] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3490459/7-considerations-when-buying-network-automation-tools.html
+
+作者：[Zeus Kerravala][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Zeus-Kerravala/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/newsletters/signup.html
+[2]: https://www.networkworld.com/article/3209131/what-sdn-is-and-where-its-going.html
+[3]: https://www.networkworld.com/article/3031279/sd-wan-what-it-is-and-why-you-ll-use-it-one-day.html
+[4]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[5]: https://www.networkworld.com/article/3230457/what-is-a-firewall-perimeter-stateful-inspection-next-generation.html
+[6]: https://www.networkworld.com/article/3202699/what-is-intent-based-networking.html
+[7]: https://www.facebook.com/NetworkWorld/
+[8]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191217 How open source eases the shift to a hybrid cloud strategy.md b/sources/talk/20191217 How open source eases the shift to a hybrid cloud strategy.md
new file mode 100644
index 0000000000..8e732f31b9
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+++ b/sources/talk/20191217 How open source eases the shift to a hybrid cloud strategy.md
@@ -0,0 +1,64 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How open source eases the shift to a hybrid cloud strategy)
+[#]: via: (https://opensource.com/article/19/12/open-source-hybrid-cloud)
+[#]: author: (Bart Copeland https://opensource.com/users/bartcopeland)
+
+How open source eases the shift to a hybrid cloud strategy
+======
+Open source software is key to adopting a multicloud or hybrid cloud
+strategy.
+![Person on top of a mountain, arm raise][1]
+
+Cloud adoption continues to grow as organizations seek to move away from legacy and monolithic strategies. Cloud-specific spending is expected to grow at more than six times the rate of general IT spending through 2020, according to [McKinsey Research][2]. But cloud adoption raises fear of [vendor lock-in][3], which is preventing many companies from going all-in on public cloud. This has led to a rise in multi-cloud and hybrid cloud deployments, which also have their challenges.
+
+Open source technology is the key to unlocking the value in a hybrid and multi-cloud strategy.
+
+### What's the appeal of a hybrid cloud strategy?
+
+The hybrid cloud market is growing rapidly because it offers the benefits of the cloud without some of the drawbacks. It typically costs less to move storage to the cloud than it does to maintain a private data center. At the same time, there are certain mission-critical applications and/or sensitive data that an organization may still want to keep on-premise, which is why hybrid cloud–a mix of private and public, on-prem and off-prem–is appealing.
+
+This is why [58 percent of enterprises][4] have a hybrid cloud strategy, according to the Rightscale State of the Cloud 2019 report. It is also why IBM acquired Red Hat for the kingly sum of $34 billion. IBM CEO Ginni Rometty noted at the time that hybrid cloud is a $1 trillion market and that IBM’s goal is to be number one in that market.
+
+### Common challenges of moving to a hybrid cloud strategy
+
+One challenge is the lack of a strategic plan. According to [McKinsey Research][2], many companies fall into the trap of thinking that simply moving IT systems to the cloud is equivalent to a transformational digital strategy. The "lift and shift" approach is not enough to enjoy all the benefits of the cloud, though.
+
+Cybersecurity applications provide a good case in point. The traditional perimeter approach to security won’t translate well to the cloud, whose approach must be quite different since a cloud perimeter is nearly impossible to define. If organizations are relying on legacy perimeter security to keep their holdings in the cloud safe, they are in for a nasty surprise.
+
+Another challenge to effective cloud migration is the status quo. For many companies, it comes down to the mindset of "If it’s not broken, why fix it? If it works fine as it is, why move it?" While many organizations understand the need for and benefits of having newer applications in the cloud, it’s not always obvious whether it also makes sense to move legacy applications over, too. In the case of cybersecurity, it very well may not be, but other applications may be best served with a move to the cloud.
+
+To further complicate matters, public cloud providers like Microsoft Azure, Google Cloud, and AWS [are not immune to outages][5]. Whatever the reason for downtime–a database glitch, bad weather, overzealous security features–being able to share workloads across clouds can be key in the event of an outage.
+
+### Bringing it all together with open source
+
+Hybrid cloud and open source go hand-in-hand. In fact, many of the public cloud providers rely heavily on different open source technologies and technology stacks to run them, so open source can be used easily across both private and public clouds in most situations. Companies like [Red Hat][6], in fact, were built on the concept of facilitating hybrid cloud. Many of its customers are moving toward an open hybrid cloud strategy.
+
+This is, in part, because open source provides flexibility and helps avoid the issues of cloud vendor lock-in. In addition, open source technologies bring breadth and depth for managers and developers alike; they give developers the tools they enjoy using.
+
+Though the cloud market is growing quickly, it is not without its limitations and drawbacks. The majority of enterprises have what they call a hybrid cloud strategy, but it may be less strategic than they think since the "lift and shift" approach falls short. Mindsets need to shift as well to overcome the status quo, and organizations need to guard against cloud outages.
+
+Vital to a multi-cloud approach is managing distributed workloads. Modern software architecture methodologies break monolithic applications into microservices that can be run wherever it makes sense–on-premise, in the cloud, or across both. By leveraging open source technologies from Linux to containers to Kubernetes, organizations can deploy, run and manage workloads in a secure and optimized manner. This kind of open source approach allows organizations to derive benefits far beyond just "lift and shift" in order to become more efficient, run their processes more cost-effectively, and adopt a more flexible operating model.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/open-source-hybrid-cloud
+
+作者：[Bart Copeland][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/bartcopeland
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/developer_mountain_cloud_top_strong_win.jpg?itok=axK3EX-q (Person on top of a mountain, arm raise)
+[2]: https://www.mckinsey.com/business-functions/mckinsey-digital/our-insights/cloud-adoption-to-accelerate-it-modernization
+[3]: https://searchconvergedinfrastructure.techtarget.com/definition/vendor-lock-in
+[4]: https://www.flexera.com/about-us/press-center/rightscale-2019-state-of-the-cloud-report-from-flexera-identifies-cloud-adoption-trends.html
+[5]: https://www.crn.com/slide-shows/cloud/the-10-biggest-cloud-outages-of-2018
+[6]: https://siliconangle.com/2019/04/12/red-hat-strategy-validated-as-open-hybrid-cloud-goes-mainstream-googlenext19/
diff --git a/sources/talk/20191217 SD-WAN management means more than reviewing logs and parsing events.md b/sources/talk/20191217 SD-WAN management means more than reviewing logs and parsing events.md
new file mode 100644
index 0000000000..89a9e3acc9
--- /dev/null
+++ b/sources/talk/20191217 SD-WAN management means more than reviewing logs and parsing events.md
@@ -0,0 +1,126 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (SD-WAN management means more than reviewing logs and parsing events)
+[#]: via: (https://www.networkworld.com/article/3490333/sd-wan-management-means-more-than-reviewing-logs-and-parsing-events.html)
+[#]: author: (Matt Conran https://www.networkworld.com/author/Matt-Conran/)
+
+SD-WAN management means more than reviewing logs and parsing events
+======
+Creating a single view of the different types of data requires specialized skills, custom integration and a significant budget. Just look at the SIEM.
+Getty Images
+
+By creating a single view of all network data, you can do things better like correlating threat information to identify real attacks or keep a log of packet statistics to better diagnose intermittent networking problems.
+
+However, to turn data into value with the limitations of traditional systems, we must be creative with the solution. We must find ways to integrate the different repositories in various appliances. It’s not an easy task but an architectural shift that I’ve written about in the past, SASE (Secure Access Service Edge), should help significantly.
+
+SASE is a new enterprise networking technology category introduced by Gartner in 2019. It represents a change in how we connect our sites, users, and cloud resources.
+
+[][1]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][1]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+This can be of considerable support, especially when it comes to the challenges faced with SIEM (Security Information and Event Management).
+
+### Creating a single view is challenging
+
+Creating a single view of the different types of data requires specialized skills, custom integration, and a significant budget. The SIEM is used to bring data from multiple products, apply rules and orchestrate a variety of platforms to act together. In reality, there is a lot of custom integration involved.
+
+The questions that surface is; how do logs get into the SIEM when off the network? How do you normalize the data, write the rules to detect for suspicious activity and then investigate if there are legitimate alerts? Unfortunately, the results are terrible for the investment that people make. The SIEM can’t be performed in a small organization. You will need the resources to pull it off.
+
+### Challenges with the SIEM
+
+In a previous consultancy role, I experienced first-hand the challenges of running a SIEM. Ultimately, the company had to improve its security monitoring. Like most, they came across the same problem and recognized there was a big gap when it came to detection.
+
+[The time of 5G is almost here][2]
+
+When I first came across the potentials of the SIEM, like most, I was thoroughly excited by its hype. Now, there was a tool that allowed me to take my ideas and run them against numerous rich data sets. From these sets, I could get immediately gain insight into threats on the network and act. However, this is far from reality - the SIEM is complex.
+
+### Different data from different devices
+
+Both security and networking store and expose data differently. Each of them carries out an individual role and have access to different data. Data can be abstracted from the management, control and data planes to build analytics that can be queried. This results in multiple levels of data available for analysis. Essentially, for this, you need to be an expert in each of these planes.
+
+Preparing all the data gathered from your entire infrastructure is complicated. Developing a timeline of events requires mastering a range of protocols and APIs just to retrieve the necessary data from networking and security appliances. Therefore, it can be a challenge to find the right data for your problem.
+
+### First, you need to collect the right data
+
+Firstly, you need to collect the right data - the SIEM is only as good as the data you feed it with. This emerges the urge for the right data that needs to get loaded to the SIEM. Since the data available with SIEM rules is provided from logs and event data from other software products, the quality of the data comes down to what was first chosen to be logged. This is compounded by the accuracy/availability of the SIEM vendor's connector.
+
+The data may be fed into the SIEM with Syslog, which requires parsing, loss of data and context from the original source. Evidently, a lot of the times, the SIEM is loaded with useless data. Many often stumble with this first step.
+
+### Aggregate the data
+
+When new threats materialize, it’s challenging to gather more data to support the new detection rules. There is also a long lead time associated with collecting new data and putting the brakes on agility. In short, the SIEM requires extensive data collection infrastructure and inter-team collaboration.
+
+### Normalize the data
+
+There will also be some kind of normalizing event where the data is cleaned up. Here, data interpretation and normalization technologies are needed to store the event data in a common format for analysis.
+
+A big claim-to-fame for the SIEM products is that they normalize data input. If you examine a windows security event, there is a big distinction between each of these events. Therefore, it’s recommended not to count on the SIEM products to interpret the inputs they receive.
+
+### No investigation support
+
+The SIEM has no investigation support. Hence, once the data is in your SIEM, you must be the one to tell the SIEM what to do with it. It’s like buying an alarm clock without the batteries. Consider an intrusion detection system, we all know that a skilled analyst is required to translate the output into actionable intelligence; a SIEM is no different.
+
+Typically, the SIEM rules are targeted for detecting the activities of interest rather than investigating them. For example, an event can only tell you that a file was uploaded. However, it tells nothing about what type of site it was uploaded to, where it came from and what the file was.
+
+This, predominantly, involves investigation between the security analyst and the operations team. Performing the querying and utilizing this information requires specialized skills and knowledge.
+
+### Deployment/resource-heavy
+
+A lot of resources are spent to manage SIEM. Time is needed for deploying agents, parsing logs, or performing the upgrade. Concisely, SIEM technology requires 24x7 monitoring and maintenance. By and large, the SIEM takes too long to deploy and some of these stages can even take years to complete. You really need a handful of full-time security analysts to do this. As it stands, there is a worldwide shortage of experienced security analysts.
+
+### Point solutions address one issue
+
+The way networking and security have been geared up is that we are sold everything in pieces. We have point solutions that only address one issue. Then there are servers, routers, switches and a variety of security devices. When a device operates within its own domain, it will only see that domain. Therefore, these point solutions need to be integrated so the user can form a picture of what is happening on the network.
+
+Consider an IDS, it looks at individual packets and tries to ascertain whether there is a threat or not. Practically, it does not have a holistic overall view of what is truly happening in networking. So, when you actually identity there was a problem, you simply don’t have the right information at hand to identify who the user is, what it does and what happened.
+
+For threat investigation, the user will need to log on to other systems and glue the information. This will result in a high number of false positives in a world that already has alert-fatigue.
+
+### How SASE can help – a common datastore
+
+Significantly, SASE converges the functions of both networking and security into a unified and global cloud-native service. Therefore, it pulls data from both the domains into a common data store. There are of course many benefits to this but one of the substantial benefits is troubleshooting.
+
+SASE vendors could make it very easy to drill deep into the networking and security events that should already be stored and normalized in a common data warehouse. SASE unlocks the potential for super-efficient troubleshooting without the pain of deploying a SIEM.
+
+A case in point is Cato network’s recent announcement of [Cato Instant*Insight][3]. The new feature to its SASE platform provides a single tool for mining the security and networking event data generated across a customer’s Cato instance. That’s how SASE helps. Profoundly, everything becomes easier when your networking and security data is being gathered by one platform.
+
+With data pulled together, investigation and analysis become easier. Cato Instant*Insight, for example, organizes the millions of networking and security events tracked by Cato into a single and queryable timeline. Here we have an automated aggregation, faceted search, and a built-in network analysis workbench.
+
+[Netsurion][4], another SD-WAN vendor, provides a managed SIEM service. This is offered as SOC-as-a-Service. However, with this and other managed SIEMs, there may still be a strong separation between the network domain and a security domain. In the sense that they’re only gathering security data and not network data. Therefore, both NOC and SOC teams have a fragmented view. And the common challenge for the enterprise will still remain.
+
+With the SIEM, there is no such thing as delivering visibility out-of-the-box. Realistically, it requires extensive custom integration and development. For many companies, SIEMs wasn’t feasible. The integration costs were just too high and too much time was needed to gather baseline data.
+
+But that’s all premised on a misconception that you continue to build your network from the appliances from different vendors. If you were to replace appliances with a converged cloud infrastructure, then you eliminate much of the challenge of the SIEM.
+
+**This article is published as part of the IDG Contributor Network. [Want to Join?][5]**
+
+Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3490333/sd-wan-management-means-more-than-reviewing-logs-and-parsing-events.html
+
+作者：[Matt Conran][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Matt-Conran/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[2]: https://www.networkworld.com/article/3354477/mobile-world-congress-the-time-of-5g-is-almost-here.html
+[3]: https://www.catonetworks.com/news/it-managers-analyze-1-million-events-in-1-second-at-no-charge-with-cato-instant-insight/
+[4]: https://www.netsurion.com/solutions/threat-protection
+[5]: https://www.networkworld.com/contributor-network/signup.html
+[6]: https://www.facebook.com/NetworkWorld/
+[7]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191217 X factor- Populating the globe with open leaders.md b/sources/talk/20191217 X factor- Populating the globe with open leaders.md
new file mode 100644
index 0000000000..ee58b9f2d1
--- /dev/null
+++ b/sources/talk/20191217 X factor- Populating the globe with open leaders.md
@@ -0,0 +1,77 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (X factor: Populating the globe with open leaders)
+[#]: via: (https://opensource.com/open-organization/19/12/open-leaders-x-mozilla)
+[#]: author: (chadsansing https://opensource.com/users/csansing)
+
+X factor: Populating the globe with open leaders
+======
+Open Leaders X, a growing program supported by Mozilla, aims to
+cultivate leaders who think and act openly—all over the world.
+![Leaders are catalysts][1]
+
+At Mozilla, we think of open leadership as a set of principles, practices, and skills people can use to mobilize their communities to solve shared problems and achieve shared goals. Open leaders design and build projects that empower others to collaborate within inclusive communities.
+
+[Mozilla's Open Leaders program][2] connects and trains leaders from around the world whose communities can help one another address the challenges and opportunities they face in creating a healthier internet, more trustworthy AI, and better online lives for all.
+
+### Starting small
+
+Open Leaders began in 2016 with a face-to-face meeting between dozens of scientists interested in creating more open labs, datasets, methods, and communications. Their passion, questions, and insights helped shape "working open workshops," which quickly developed into an open leadership curriculum reaching hundreds of people online—from all across the open ecosystem.
+
+What began as a small, collaborative inquiry into the nature and possibilities of open science has become a thriving community of open leaders helping one another infuse their projects and cultures with the principles and practices of openness.
+
+While [Mozilla staffers][3] have historically organized the program, returning graduates have served as the experts, mentors, and community call co-hosts of each subsequent round of programming, contributing their time and expertise back to the program and its participants. They have also helped us at Mozilla better participate in discussions of engagement, value exchange, sustainability, power-sharing, care, and labor (among many, many other interwoven open topics).
+
+We are humbled by the notion that a meeting of 25 like-minded people dedicated to opening their practice in science has become a network of hundreds of leaders working to connect their home communities and parts of the open ecosystem—like open art, campaigning, data, education, hardware, government, and software—with the [internet health movement][4] and the push for more [trustworthy AI][5].
+
+### Growing up
+
+At Mozilla, we think of open leadership as a set of principles, practices, and skills people can use to mobilize their communities to solve shared problems and achieve shared goals.
+
+As we tried to think of how best to bring core lessons from the Open Leaders program to the global MozFest community while also sustaining the program, we organized the most recent round of Open Leaders—the last we'll organize for now—as a train-the-trainer program. Working with program graduates, Mozilla staff and fellows, and [leads from 10 different community projects][6], we co-designed Open Leaders X (OLx) to help community members run, connect, and sustain their own open leadership programs. We hoped that by distributing the development and ownership of Open Leaders across the open ecosystem and internet health movement, we could ensure its survival and strengthen its development through community co-ownership. This would allow each program to tailor itself to the needs, challenges, and opportunities each group faces.
+
+We are so proud of the entire Open Leaders community and especially grateful to our OLx leads and contributors, who took the plunge with us and dove into this new train-the-trainer model. Rather than close the loop on Open Leaders, the decision to make it a community-driven program continues its upward spiral.
+
+In October, we brought together nearly all 30 of our OLx leads at [MozFest 2019][7], the momentous 10th anniversary of the festival. They launched their programs and issued their calls for applications, as well as their invitations to community members (like you!) to serve as mentors, experts, and guest speakers for each program. In 2020, these 30 leads and their 10 projects will welcome the next 200 open leaders into the community and the internet health movement.
+
+We look forward to all the new connections we'll make together between these new Open Leaders cohorts and the burgeoning MozFest community. Our goal is to help people across these communities stay connected and engaged with both one another and the open, federated principles and practices of MozFest all year long.
+
+We can't wait to collaborate, learn together and to discover what's next for Open Leaders, internet health, and more trustworthy AI.
+
+You are invited to join this work and all of its challenges, learning, and fun! Watch the OLx launch party videos and find links to each program [online][8]!
+
+You can also check out the [OLx syllabus][9]. You can even look further back at the most recent Open Leaders syllabi from round 7, both the [project track][10] and the [culture track][11]. You can visit [Mozilla Pulse][12], as well, to keep track of each project and [sign up for our newsletter][13] to keep up with our latest programming.
+
+We hope you'll join the Open Leaders community and visit us at the next MozFest! We can't wait to collaborate, learn together and to discover what's next for Open Leaders, internet health, and more trustworthy AI.
+
+My theme this week is organizational openness and transparency and today I'd like to highlight a...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/open-organization/19/12/open-leaders-x-mozilla
+
+作者：[chadsansing][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/csansing
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/leaderscatalysts.jpg?itok=f8CwHiKm (Leaders are catalysts)
+[2]: https://foundation.mozilla.org/en/opportunity/mozilla-open-leaders/
+[3]: https://foundation.mozilla.org/en/initiatives/open-leadership-events/who-we-are/
+[4]: https://internethealthreport.org/
+[5]: https://medium.com/read-write-participate/update-digging-deeper-on-trustworthy-ai-588fcd01a321
+[6]: https://medium.com/read-write-participate/meet-the-open-leaders-x-cohort-1dc230a4c56a
+[7]: https://mozillafestival.org
+[8]: https://foundation.mozilla.org/en/blog/streaming-week-open-leaders-x/
+[9]: https://docs.google.com/document/d/1rKvMn0uXSoLvOj7t1jEW9JkQePqhGRu37V1YEMeV8Nw/edit
+[10]: https://docs.google.com/document/d/1G_opVoiO1VXlfjs-xvbbHVaF97jZBE3DH-DWxAEqtT4/edit?usp=sharing
+[11]: https://docs.google.com/document/d/1dpH_LPZQ2FTUbK1y1tIDrJfYvesFp3Ivwqp1_jju-5E/edit#heading=h.5qlxraoq91j2
+[12]: https://www.mozillapulse.org/projects?keyword=olx
+[13]: https://foundation.mozilla.org/en/initiatives/open-leadership-events/
diff --git a/sources/talk/20191218 Cisco- 5 hot networking trends for 2020.md b/sources/talk/20191218 Cisco- 5 hot networking trends for 2020.md
new file mode 100644
index 0000000000..81f942c347
--- /dev/null
+++ b/sources/talk/20191218 Cisco- 5 hot networking trends for 2020.md
@@ -0,0 +1,135 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Cisco: 5 hot networking trends for 2020)
+[#]: via: (https://www.networkworld.com/article/3505883/cisco-5-hot-networking-trends-for-2020.html)
+[#]: author: (Michael Cooney https://www.networkworld.com/author/Michael-Cooney/)
+
+Cisco: 5 hot networking trends for 2020
+======
+Cisco exec says SD-WAN, Wi-Fi 6, multi-domain control, virtual networking and the evolving role of network engineers will be big in 2020
+Thinkstock
+
+[Hot trends][1] in networking for the coming year include [SD-WAN][2], [Wi-Fi 6][3], multi-domain control, virtual networking and the evolving role of the network engineer into that of a network progrmmer, at least according to [Cisco][4].
+
+They revolve around the changing shape of networking in general, that is the broadening of [data-center][5] operations into the cloud and the implications of that change, said Anand Oswal, senior vice president of engineering in Cisco’s Enterprise Networking Business.
+
+“These fundamental shifts in where business processes run and how they’re accessed, is changing how we connect our locations together, how we think about security, the economics of networking, and what we ask of the people who take care of them,” Oswal said.
+
+[][6]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][6]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+[See more predictions about what's big in IT tech for the coming year.][7]
+
+In [blog][8] outlining the key trends for 2020, Oswal detailed his thoughts about the five areas.
+
+### Wi-Fi 6 and 5G
+
+First up, wireless technology – especially Wi-Fi 6 – will get into the enterprise through the employee door and through enterprise access-point refreshes. The latest smartphones from Apple, Samsung, and other manufacturers are Wi-Fi 6 enabled, and Wi-Fi 6 access points are currently shipping to businesses and consumers.
+
+5G phones are not yet in wide circulation, although that will begin to change in 2020, athough mostly for consumers and towards the end of the year. Oswal wrote that Cisco projects more people will be using Wi-Fi 6 than 5G through 2020.
+
+2020 will also see the beginning of a big improvement in how people use Wi-Fi networks. The potential growth of the Cisco-lead OpenRoaming project will make joining participating Wi-Fi networks much easier, Oswal said. [OpenRoaming][9], which uses the underlying technology behind HotSpot 2.0/ IEEE 802.11u promises to let users move seamlessly between wireless networks and LTE without interruption -- emulating mobile network connectivity. Current project partners include Samsung, Boingo, and GlobalReach Technologies.
+
+2020 will also see the adoption of new frequency bands, including the beginning of the rollout of “millimeter wave” (24Ghz to 100Ghz) spectrum for ultra-fast, but short-range 5G as well as Citizens Broadband Radio Service (CBRS), at about 3.5Ghz. This may lead to new _private_ networks that use LTE and 5G technology, especially for IoT applications.
+
+“We will also see continued progress in opening up the 6GHz range for unlicensed Wi-Fi usage in the United States and the rest of world,” Oswal wrote.
+
+As for [5G][10] services, some will roll out in 2020 but “almost none of it will be the ultra-high speed connectivity that we have been promised or that we will see in future years,” Oswal said. “With 5G unable to deliver on that promise initially, we will see a lot of high-speed wireless traffic offloaded to Wi-Fi networks.”
+
+In the long run, “In combination with the improved performance of both Wi-Fi 6 and (eventually) 5G, we are in for a large – and long-lived – period of innovation in access networking,” Oswal wrote.
+
+### It’s a SD-WAN world
+
+“We are seeing a ton of momentum in the SD-WAN area as large numbers of companies need secure access to cloud applications,” Oswal said. The dispersal of connectivity – the growth of multicloud networking – will force many businesses to re-tool their networks in favor of SD-WAN technology, he said.
+
+“Meanwhile the large cloud service providers, like [Amazon, Google, and Microsoft][1], are connecting to networking companies – like Cisco – to forge deep partnership links between networking stacks and services,” Oswal wrote.
+
+Oswal said he expects such partnerships will only deepen next year, and that concurs with recent analysis by Gartner.
+
+“SD-WAN is replacing routing and adding application-aware path selection among multiple links, centralized orchestration and native security, as well as other functions. Consequently, it includes incumbent and emerging vendors from multiple markets (namely routing, security, WAN optimization and SD-WAN), each bringing its own differentiators and limitations,” [Gartner wrote][11] in a recent report.
+
+In addition Oswal said SD-WAN technology is going to lead to a growth in business for managed service providers (MSPs), many more of which will begin to offer SD-WAN as a service.
+
+“We expect MSPs to grow at about double the rate of the SD-WAN market itself, and expect that MSPs will begin to hyper-specialize, by industry and network size,” Oswal wrote.
+
+### All-inclusive multi-domain networks
+
+In the Cisco world, blending typically siloed domains across the enterprise and cloud to the wide-area network is getting easier, and Oswal says that will continue in 2020. The idea is that its key software components – [Application Centric Infrastructure (ACI) and DNA Center][12] – now enable what Cisco calls multidomain integration, which lets customers set policies to apply uniform access controls to users, devices and applications regardless of where they connect to the network.
+
+ACI is [Cisco’s software-defined networking][13] ([SDN][13]) data-center package, but it also delivers the company’s intent-based networking technology, which brings customers the ability to automatically implement network and policy changes on the fly and ensure data delivery.
+
+DNA Center is a key package as it features automation capabilities, assurance setting, fabric provisioning and policy-based segmentation for enterprise networks. Cisco DNA Center gives IT teams the ability to control access through policies using software-defined access (SD-Access), automatically provision through Cisco DNA Automation, virtualize devices through Cisco Network Functions Virtualization (NFV), and lower security risks through segmentation and encrypted traffic analysis.
+
+“For better management, agility, and especially for security, these multiple domains need to work together,” Oswal wrote. “Each domain’s controller needs to work in a coordinated manner to enable automation, analytics and security across the various domains.”
+
+The next generation of controller-first architectures for network fabrics allows the unified management of loosely coupled systems using APIs and defined data structures for inter-device and inter-domain communication, Oswal wrote. “The intent-based networking model that enterprises began adopting in 2019 is making network management more straightforward by absorbing the complexities of the network,” he wrote.
+
+### The network as sensor
+
+The notion of the [network being used for something more important][14] than speeds and feeds has been talked about for a while, but the idea may be coming home to roost next year.
+
+“With software that is able to profile and classify the devices, end points, and applications – even when they are sending fully encrypted data – the network will be able to place the devices into virtual networks automatically, enable the correct rule set to protect those devices, and eventually identify security issues extremely quickly,” Oswal wrote.
+
+“Ultimately, systems will be able to remediate issues on their own, or at least file their own help-desk tickets. This becomes increasingly important as networks grow increasingly complex.”
+
+Oswal said this intelligence could prove useful in wireless networks where the network can collect data on how people and things move through and use physical spaces, such as IoT devices in a business or medical devices in a hospital.
+
+“That data can directly help facility owners optimize their physical spaces, for productivity, ease of navigation, or even to improve retail sales,” Oswal wrote. “These are capabilities that have been rolling out in 2019, but as business execs become aware of the power of this location data, the use of this technology will begin to snowball.”
+
+### The network engineer career change
+
+The growing software-oriented network environment is changing the resume requirements of network professional. “The standard way that network operators work – provisioning network equipment using command-line interfaces like CLI – is nearing the end of the line,” Oswal wrote. “Today, _intent-based networking_ lets us tell the network what we want it to do, and leave the individual device configuration to the larger system itself.”
+
+Oswal said customers can now program updates, rollouts, and changes using centralized networking controllers*,* rather than working directly with devices or their own unique interfaces.
+
+“New networks run by APIs require programming skills to manage,” Oswal wrote. “Code is the resource behind the creation of new business solutions. It remains critical for individuals to validate their proficiency with new infrastructure and network engineering concepts.”
+
+Oswal noted that it will not be an easy change because retraining individuals or whole teams can be expensive, and not everyone will adapt to the new order.
+
+“For those that do, the benefits are big,” Oswal said. “Network operators will be closer to the businesses they work for, able to better help businesses achieve their digital transformations. The speed and agility they gain thanks to having a programmable network, plus telemetry and analytics, opens up vast new opportunities.”
+
+This year [Cisco revamped some of its most critical certification][15] and career-development tools in an effort to address the emerging software-oriented network environment. Perhaps one of the biggest additions is the [new set of professional certifications][16] for developers utilizing Cisco’s growing DevNet developer community.
+
+The Cisco Certified DevNet Associate, Specialist and Professional certifications will cover software development for applications, automation, DevOps, cloud and IoT. They will also target software developers and network engineers who develop software proficiency to develop applications and automated workflows for operational networks and infrastructure.
+
+Join the Network World communities on [Facebook][17] and [LinkedIn][18] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3505883/cisco-5-hot-networking-trends-for-2020.html
+
+作者：[Michael Cooney][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Michael-Cooney/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3489938/what-s-hot-at-the-edge-for-2020-everything.html
+[2]: https://www.networkworld.com/article/3031279/sd-wan-what-it-is-and-why-you-ll-use-it-one-day.html
+[3]: https://www.networkworld.com/article/3258807/what-is-802-11ax-wi-fi-and-what-will-it-mean-for-802-11ac.html
+[4]: https://www.networkworld.com/article/3487831/what-s-hot-for-cisco-in-2020.html
+[5]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
+[6]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[7]: https://www.networkworld.com/article/3488562/whats-big-in-it-tech-for-the-coming-year.html
+[8]: https://blogs.cisco.com/enterprise/enterprise-networking-in-2020-5-trends-to-watch
+[9]: https://blogs.cisco.com/wireless/openroaming-seamless-across-wi-fi-6-and-5g?oid=psten016624
+[10]: https://www.networkworld.com/article/3203489/what-is-5g-how-is-it-better-than-4g.html
+[11]: https://www.networkworld.com/article/3489480/secure-sd-wan-the-security-vendors-and-their-sd-wan-offerings.html
+[12]: https://www.networkworld.com/article/3401523/cisco-software-to-make-networks-smarter-safer-more-manageable.html
+[13]: https://www.networkworld.com/article/3209131/what-sdn-is-and-where-its-going.html
+[14]: https://www.networkworld.com/article/3400382/cisco-will-use-aiml-to-boost-intent-based-networking.html
+[15]: https://www.networkworld.com/article/3401524/cisco-launches-a-developer-community-cert-program.html
+[16]: https://www.networkworld.com/article/3446044/are-new-cisco-certs-too-much-network-pros-react.html
+[17]: https://www.facebook.com/NetworkWorld/
+[18]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191219 Bamboo Systems redesigns server motherboards for greater performance.md b/sources/talk/20191219 Bamboo Systems redesigns server motherboards for greater performance.md
new file mode 100644
index 0000000000..44234d2b72
--- /dev/null
+++ b/sources/talk/20191219 Bamboo Systems redesigns server motherboards for greater performance.md
@@ -0,0 +1,68 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Bamboo Systems redesigns server motherboards for greater performance)
+[#]: via: (https://www.networkworld.com/article/3490385/bamboo-systems-redesigns-server-motherboards-for-greater-performance.html)
+[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
+
+Bamboo Systems redesigns server motherboards for greater performance
+======
+Bamboo Systems, formerly Kaleao, claims its motherboard architecture is more power efficient than traditional designs that cater to x86 processors.
+Thinkstock
+
+UK chip designer Kaleao has re-launched as Bamboo Systems with some pre-Series A funding and claims its [Arm][1]-based server chips will be considerably more power efficient than the competition.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][2]
+
+Bamboo is targeting x86 servers, which have a 95% market share, unlike Marvell with its [ThunderX2][3] and Ampere Systems with its [eMAG Arm processors][4]. The company argues that the two Arm processors are no different than x86.
+
+“Marvell and Ampere are chip manufacturers that have built a chip to pretty much slot into the motherboard and chassis configuration that an Intel/AMD chip would fit into. They are therefore going head on against Intel/AMD as chip manufacturers – and history is showing, not creating a sustainable solution for the OEMs,” says John Goodacre, co-founder and chief scientific officer of Bamboo.
+
+[][5]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][5]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+The motherboard is changed, but the CPU and software layer are not. Currently the company is in the prototype stage. Its server is based on Samsung Arm Cortex-A57 design, so the CPU itself is not changed. Even though they have essentially thrown out traditional motherboard design, Goodacre said the software is fully compatible and will run unchanged. So Linux and Arm-based apps will all run.
+
+Goodacre, a 17-year veteran of Arm and researcher at the University of Manchester working on exascale research projects, said just putting more cores in a die in a workstation designed system isn’t the most power efficient way to build scale out power efficient servers.
+
+“We realized that the system architecture was where your power was consumed more than instruction set. There have been several Arm chips [in servers] and they show the difference in power efficiency in an Arm gives you a few tens of percent. There is very little power efficiency in Arm over x86,” he said.
+
+What he noticed was that because of the motherboard and all of its ports, like USB and I/O, a lot of power was wasted on the motherboard resources. Kaleo, now Bamboo, redesigned the whole motherboard where things like I/O and memory are pooled, so doubling the processor count doesn’t require doubling of motherboards.
+
+This means a shared infrastructure with pooling of non-CPU resources and NVMe to scale up storage. A 3U box can hold up to 192 eight-core servers, 42 U.2 SSDs and 192 directly attached SATA 6 drives.
+
+“The concept of a motherboard is gone. Instead, you put the infrastructure to support processors. We build clusters of machines on boards where the infrastructure is shared across processor elements,” he said.
+
+The result, he claims, is the Bamboo system can deliver the same amount of web traffic in 10x less server space for 5x less energy. “One rack of our stuff equals 10 racks of the competition,” said Goodacre.
+
+Bamboo says it will announce more details in early January.
+
+Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3490385/bamboo-systems-redesigns-server-motherboards-for-greater-performance.html
+
+作者：[Andy Patrizio][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Andy-Patrizio/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/article/3306447/a-new-arm-based-server-processor-challenges-for-the-data-center.html
+[2]: https://www.networkworld.com/newsletters/signup.html
+[3]: https://www.networkworld.com/article/3271073/cavium-launches-thunderx2-arm-based-server-processors.html
+[4]: https://www.networkworld.com/article/3482248/ampere-preps-an-80-core-arm-processor-for-the-cloud.html
+[5]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[6]: https://www.facebook.com/NetworkWorld/
+[7]: https://www.linkedin.com/company/network-world
diff --git a/sources/talk/20191220 Why We Need Interoperable Service Identity.md b/sources/talk/20191220 Why We Need Interoperable Service Identity.md
new file mode 100644
index 0000000000..7ca8470bf7
--- /dev/null
+++ b/sources/talk/20191220 Why We Need Interoperable Service Identity.md
@@ -0,0 +1,59 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Why We Need Interoperable Service Identity?)
+[#]: via: (https://www.linux.com/articles/why-we-need-interoperable-identity/)
+[#]: author: (TC CURRIE https://www.linux.com/author/tc_currie/)
+
+Why We Need Interoperable Service Identity?
+======
+
+[![][1]][2]
+
+[![][1]][2]
+
+Interoperable service identity is necessary to secure communication between different cloud providers and different platforms. This presents a challenge with multi-cloud and hybrid deployments. How do you secure service to service communication across those boundaries?
+
+Evan Gilman, Staff Engineer at [Scytale.io][3] and co-author of _Zero Trust Networks_, illustrates this issue: when you’re in AWS, you’ll use an AWS IAM role in order to identify which instance a certain role should or should not have access to. But in today’s multi-platform world, you can be communicating from AWS to GCP to your on-prem infrastructure. Those systems do not understand what IAM role is because it is AWS-specific.
+
+This is what Scytale is trying to address. *“*We are bringing a platform-agnostic identity, meaning, an identity that is not specific to a cloud provider or a platform, or any specific kind of technology,” he said.
+
+**What’s SPIFFE?**
+
+[Secure Production Identity Framework for Everyone (SPIFFE)][4] is a set of specifications that define interoperability across all tech platforms, such as how to format the name, the shape of the document, how you validate documents, etc. “This SPIFFE level is like a secure dial tone,” Gilman explains. “You pick up the phone, it rings the other side, doesn’t really matter what platform it is or where it’s running or anything like that. The SPIFFE authentication occurs and you get a nice little layer of encryption and some authenticity insurances as well.”
+
+But at the end of the day, SPIFFE is just a set of documents. SPIRE is the software implementation of the SPIFFE specifications.
+
+“Think about the way the passports work,” he said. “If you look at passports from different countries, they may be slightly different, but they have similar characteristics like SPIFFE specifications. They’re all the same size. They all have a picture in the same spot. They have the same funny-looking barcode at the bottom, and so on. So, when you show your passport at a country border, they know how to read your passport, no matter what country that passport is from. SPIRE is the passport agency in this analogy. Where does this passport come from? Who gives it to you? How do you get it and how do you do that in an automated fashion?”
+
+SPIRE implements these SPIFFE specifications and enables workloads and services to get these passports as soon as they boot in a way that is very reliable, scalable, and very highly automated.
+
+**Zero Trust**
+
+Gilman is taking the philosophy of Zero Trust — don’t trust anybody whatsoever — and applying it to network infrastructure and service-to-service communication. “We do this by removing all the security functions from the network and making no assumptions about what should or should not be allowed based on IP address,” he said.
+
+“Instead, we build systems in such a way that they don’t rely on that network to deliver trustworthy information. We use protocols for strong authentication and authorization to try to mitigate any kind of funny business that might happen on the wire.”
+
+**Into the New Decade**
+
+For Scytale, Gilman’s biggest push for 2020 is to provide documentation with detailed examples of how to solve different use cases, and how to configure the software to solve those use cases. “Very clear-cut guidance,” he states. “We have a lot of flexibility and features built into the software, but we don’t have conceptual guidelines that can teach people how the internals are working and stuff like that. We button everything up and make the experience really easy to pick up for folks who might not necessarily want to get in the weeds with it. They just want it to work.”
+
+--------------------------------------------------------------------------------
+
+via: https://www.linux.com/articles/why-we-need-interoperable-identity/
+
+作者：[TC CURRIE][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.linux.com/author/tc_currie/
+[b]: https://github.com/lujun9972
+[1]: https://www.linux.com/wp-content/uploads/2019/12/computer-2930704_1280-696x413.jpg (computer-2930704_1280)
+[2]: https://www.linux.com/wp-content/uploads/2019/12/computer-2930704_1280.jpg
+[3]: http://scytale.io/
+[4]: https://spiffe.io/
diff --git a/sources/talk/20191225 How to run a business with open source- Top reads.md b/sources/talk/20191225 How to run a business with open source- Top reads.md
new file mode 100644
index 0000000000..f857738495
--- /dev/null
+++ b/sources/talk/20191225 How to run a business with open source- Top reads.md
@@ -0,0 +1,63 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to run a business with open source: Top reads)
+[#]: via: (https://opensource.com/article/19/12/business-open-source)
+[#]: author: (Jim Hall https://opensource.com/users/jim-hall)
+
+How to run a business with open source: Top reads
+======
+Open source software is open for business, as evidenced in the these top
+5 articles from 2019.
+![Open for business][1]
+
+Open source is ready to get to work, and in 2019, Opensource.com had many great articles about how organizations have adopted open source software or open methods to drive their business. As open source matures, we've seen open source not just replace proprietary software, but create entirely new business models.
+
+Check out this list of five outstanding articles from Opensource.com in 2019 about running a business with open source.
+
+### Get your business up and running with these open source tools
+
+In [_Get your business up and running with these open source tools_][2], I explain: "Yes, you really can operate a business using open source software." In this article, I review the key open source software tools that I use to run my company, including Inkscape, GIMP, LibreOffice, and Scribus.
+
+### What's your favorite open source BI software?
+
+As Lauren Maffeo explains in _[What's your favorite open source BI software?][3]_ "Open source business intelligence (BI) software helps users upload, visualize, and make decisions based on data that is pulled from several sources... BI involves turning data into insights that help your business make better decisions... Before choosing which open source BI tool to adopt, it's worth weighing the pros and cons of each tool against your business needs." The article's accompanying poll asks readers whether they prefer Pentaho, Logz.io, Cluvio, Qlikview, Sisense, or another BI application. Answer the poll to let us know which is your favorite and to see what other readers say.
+
+### Scrum vs. kanban: Which agile framework is better?
+
+Because scrum and kanban both fall under the agile framework umbrella, many people confuse them or think they're the same thing. There are differences, however. In [_Scrum vs. kanban: Which agile framework is better?_][4] Taz Brown explains the differences between scrum and kanban and helps you decide which one may be best for your team.
+
+### What is Small Scale Scrum?
+
+"Agile is fast becoming a mainstream way industries act, behave, and work as they look to improve efficiency, minimize costs, and empower staff. Most software developers naturally think, act, and work this way, and alignment towards agile software methodologies has gathered pace in recent years," write Agnieszka Gancarczyk and Leigh Griffin in [_What is Small Scale Scrum?_][5] In this article, they explain how the scrum agile methodology can help small teams work more efficiently.
+
+### What does DevOps mean to you?
+
+In *[What does DevOps mean to you?][6] *Girish Managoli offers one answer to this article's headline: "DevOps is a process of software development focusing on communication and collaboration to facilitate rapid application and product deployment." But there are a range of opinions and expectations around DevOps. To help explain DevOps and how to leverage it in organizations, Girish interviewed six experts to break down DevOps and the key practices and philosophies in making DevOps work for you.
+
+### Open source is open for business
+
+As open source plays an increasingly important role in business, there's more to learn about the topic. What do you want to know about it in 2020? Please share your ideas for articles in the comments—or even share your own experiences with running a business on open source software by [writing an article for Opensource.com][7].
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/business-open-source
+
+作者：[Jim Hall][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/jim-hall
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/BUSINESS_openseries.png?itok=rCtTDz5G (Open for business)
+[2]: https://opensource.com/article/19/9/business-creators-open-source-tools
+[3]: https://opensource.com/article/19/8/favorite-open-source-bi-software
+[4]: https://opensource.com/article/19/8/scrum-vs-kanban
+[5]: https://opensource.com/article/19/1/what-small-scale-scrum
+[6]: https://opensource.com/article/19/1/what-does-devops-mean-you
+[7]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20171018 How to create an e-book chapter template in LibreOffice Writer.md b/sources/tech/20171018 How to create an e-book chapter template in LibreOffice Writer.md
index 8c6a5c8072..0d8bfed9ce 100644
--- a/sources/tech/20171018 How to create an e-book chapter template in LibreOffice Writer.md
+++ b/sources/tech/20171018 How to create an e-book chapter template in LibreOffice Writer.md
@@ -1,3 +1,4 @@
+Translating by robsean
How to create an e-book chapter template in LibreOffice Writer
======
diff --git a/sources/tech/20180130 Create and manage MacOS LaunchAgents using Go.md b/sources/tech/20180130 Create and manage MacOS LaunchAgents using Go.md
index 8bd6b8bf64..b9a477824c 100644
--- a/sources/tech/20180130 Create and manage MacOS LaunchAgents using Go.md
+++ b/sources/tech/20180130 Create and manage MacOS LaunchAgents using Go.md
@@ -1,3 +1,12 @@
+[#]: collector: (lujun9972)
+[#]: translator: (runningwater)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Create and manage MacOS LaunchAgents using Go)
+[#]: via: (https://ieftimov.com/post/create-manage-macos-launchd-agents-golang/)
+[#]: author: (https://ieftimov.com/about)
+
Create and manage MacOS LaunchAgents using Go
============================================================
@@ -287,7 +296,7 @@ This is where I write about software development, programming languages and ever
via: https://ieftimov.com/create-manage-macos-launchd-agents-golang
作者：[Ilija Eftimov ][a]
-译者：[译者ID](https://github.com/译者ID)
+译者：[runningwater](https://github.com/runningwater)
校对：[校对者ID](https://github.com/校对者ID)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
@@ -302,4 +311,4 @@ via: https://ieftimov.com/create-manage-macos-launchd-agents-golang
[7]:https://golang.org/x/sys
[8]:https://docs.google.com/document/d/1QXzI9I1pOfZPujQzxhyRy6EeHYTQitKKjHfpq0zpxZs/edit
[9]:https://golang.org/x/sys
-[10]:https://github.com/jteeuwen/go-bindata
\ No newline at end of file
+[10]:https://github.com/jteeuwen/go-bindata
diff --git a/sources/tech/20180503 How the four components of a distributed tracing system work together.md b/sources/tech/20180503 How the four components of a distributed tracing system work together.md
index 56239fc872..68ba97e989 100644
--- a/sources/tech/20180503 How the four components of a distributed tracing system work together.md
+++ b/sources/tech/20180503 How the four components of a distributed tracing system work together.md
@@ -1,3 +1,4 @@
+chenmu-kk is translating.
How the four components of a distributed tracing system work together
======
diff --git a/sources/tech/20181231 Easily Upload Text Snippets To Pastebin-like Services From Commandline.md b/sources/tech/20181231 Easily Upload Text Snippets To Pastebin-like Services From Commandline.md
deleted file mode 100644
index 58b072f2fc..0000000000
--- a/sources/tech/20181231 Easily Upload Text Snippets To Pastebin-like Services From Commandline.md
+++ /dev/null
@@ -1,259 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Easily Upload Text Snippets To Pastebin-like Services From Commandline)
-[#]: via: (https://www.ostechnix.com/how-to-easily-upload-text-snippets-to-pastebin-like-services-from-commandline/)
-[#]: author: (SK https://www.ostechnix.com/author/sk/)
-
-Easily Upload Text Snippets To Pastebin-like Services From Commandline
-======
-
-
-
-Whenever there is need to share the code snippets online, the first one probably comes to our mind is Pastebin.com, the online text sharing site launched by **Paul Dixon** in 2002. Now, there are several alternative text sharing services available to upload and share text snippets, error logs, config files, a command’s output or any sort of text files. If you happen to share your code often using various Pastebin-like services, I do have a good news for you. Say hello to **Wgetpaste** , a command line BASH utility to easily upload text snippets to pastebin-like services. Using Wgetpaste script, anyone can quickly share text snippets to their friends, colleagues, or whoever wants to see/use/review the code from command line in Unix-like systems.
-
-### Installing Wgetpaste
-
-Wgetpaste is available in Arch Linux [Community] repository. To install it on Arch Linux and its variants like Antergos and Manjaro Linux, just run the following command:
-
-```
-$ sudo pacman -S wgetpaste
-```
-
-For other distributions, grab the source code from [**Wgetpaste website**][1] and install it manually as described below.
-
-First download the latest Wgetpaste tar file:
-
-```
-$ wget http://wgetpaste.zlin.dk/wgetpaste-2.28.tar.bz2
-```
-
-Extract it:
-
-```
-$ tar -xvjf wgetpaste-2.28.tar.bz2
-```
-
-It will extract the contents of the tar file in a folder named “wgetpaste-2.28”.
-
-Go to that directory:
-
-```
-$ cd wgetpaste-2.28/
-```
-
-Copy the wgetpaste binary to your $PATH, for example **/usr/local/bin/**.
-
-```
-$ sudo cp wgetpaste /usr/local/bin/
-```
-
-Finally, make it executable using command:
-
-```
-$ sudo chmod +x /usr/local/bin/wgetpaste
-```
-
-### Upload Text Snippets To Pastebin-like Services
-
-Uploading text snippets using Wgetpaste is trivial. Let me show you a few examples.
-
-**1\. Upload text files**
-
-To upload any text file using Wgetpaste, just run:
-
-```
-$ wgetpaste mytext.txt
-```
-
-This command will upload the contents of mytext.txt file.
-
-Sample output:
-
-```
-Your paste can be seen here: https://paste.pound-python.org/show/eO0aQjTgExP0wT5uWyX7/
-```
-
-
-
-You can share the pastebin URL via any medium like mail, message, whatsapp or IRC etc. Whoever has this URL can visit it and view the contents of the text file in a web browser of their choice.
-
-Here is the contents of mytext.txt file in web browser:
-
-
-
-You can also use **‘tee’** command to display what is being pasted, instead of uploading them blindly.
-
-To do so, use **-t** option like below.
-
-```
-$ wgetpaste -t mytext.txt
-```
-
-![][3]
-
-**2. Upload text snippets to different services
-**
-
-By default, Wgetpaste will upload the text snippets to **poundpython** () service.
-
-To view the list of supported services, run:
-
-```
-$ wgetpaste -S
-```
-
-Sample output:
-
-```
-Services supported: (case sensitive):
-Name: | Url:
-=============|=================
-bpaste | https://bpaste.net/
-codepad | http://codepad.org/
-dpaste | http://dpaste.com/
-gists | https://api.github.com/gists
-*poundpython | https://paste.pound-python.org/
-```
-
-Here, ***** indicates the default service.
-
-As you can see, Wgetpaste currently supports five text sharing services. I didn’t try all of them, but I believe all services will work.
-
-To upload the contents to other services, for example **bpaste.net** , use **-s** option like below.
-
-```
-$ wgetpaste -s bpaste mytext.txt
-Your paste can be seen here: https://bpaste.net/show/5199e127e733
-```
-
-**3\. Read input from stdin**
-
-Wgetpaste can also read the input from stdin.
-
-```
-$ uname -a | wgetpaste
-```
-
-This command will upload the output of ‘uname -a’ command.
-
-**4. Upload the COMMAND and the output of COMMAND together
-**
-
-Sometimes, you may need to paste a COMMAND and its output. To do so, specify the contents of the command within quotes like below.
-
-```
-$ wgetpaste -c 'ls -l'
-```
-
-This will upload the command ‘ls -l’ along with its output to the pastebin service.
-
-This can be useful when you wanted to let others to clearly know what was the exact command you just ran and its output.
-
-![][4]
-
-As you can see in the output, I ran ‘ls -l’ command.
-
-**5. Upload system log files, config files
-**
-
-Like I already said, we can upload any sort of text files, not just an ordinary text file, in your system such as log files, a specific command’s output etc. Say for example, you just updated your Arch Linux box and ended up with a broken system. You ask your colleague how to fix it and s/he wants to read the pacman.log file. Here is the command to upload the contents of the pacman.log file:
-
-```
-$ wgetpaste /var/log/pacman.log
-```
-
-Share the pastebin URL with your Colleague, so s/he will review the pacman.log and may help you to fix the problem by reviewing the log file.
-
-Usually, the contents of log files might be too long and you don’t want to share them all. In such cases, just use **cat** command to read the output and use **tail** command with the **-n** switch to define the number of lines to share and finally pipe the output to Wgetpaste as shown below.
-
-```
-$ cat /var/log/pacman.log | tail -n 50 | wgetpaste
-```
-
-The above command will upload only the **last 50 lines** of pacman.log file.
-
-**6\. Convert input url to tinyurl**
-
-By default, Wgetpaste will display the full pastebin URL in the output. If you want to convert the input URL to a tinyurl, just use **-u** option.
-
-```
-$ wgetpaste -u mytext.txt
-Your paste can be seen here: http://tinyurl.com/y85d8gtz
-```
-
-**7. Set language
-**
-
-By default, Wgetpaste will upload text snippets in **plain text**.
-
-To list languages supported by the specified service, use **-L** option.
-
-```
-$ wgetpaste -L
-```
-
-This command will list all languages supported by default service i.e **poundpython** ().
-
-We can change this using **-l** option.
-
-```
-$ wgetpaste -l Bash mytext.txt
-```
-
-**8\. Disable syntax highlighting or html in the output**
-
-As I mentioned above, the text snippets will be displayed in a specific language format (plaintext, Bash etc.).
-
-You can, however, change this behaviour to display the raw text snippets using **-r** option.
-
-```
-$ wgetpaste -r mytext.txt
-Your raw paste can be seen here: https://paste.pound-python.org/raw/CUJhQ3jEmr2UvfmD2xCL/
-```
-
-
-
-As you can see in the above output, there is no syntax highlighting, no html formatting. Just a raw output.
-
-**9\. Change Wgetpaste defaults**
-
-All Defaults values (DEFAULT_{NICK,LANGUAGE,EXPIRATION}[_${SERVICE}] and DEFAULT_SERVICE) can be changed globally in **/etc/wgetpaste.conf** or per user in **~/.wgetpaste.conf** files. These files, however, are not available by default in my system. I guess we need to manually create them. The developer has given the sample contents for both files [**here**][5] and [**here**][6]. Just create these files manually with given sample contents and modify the parameters accordingly to change Wgetpaste defaults.
-
-**10\. Getting help**
-
-To display the help section, run:
-
-```
-$ wgetpaste -h
-```
-
-And, that’s all for now. Hope this was useful. We will publish more useful content in the days to come. Stay tuned!
-
-On behalf of **OSTechNix** , I wish you all a very **Happy New Year 2019**. I am grateful to all our readers, contributors, and mentors for supporting us from the beginning of our journey. We couldn’t come this far without your support and guidance. Thank you everyone! Have a great year ahead!!
-
-Cheers!
-
-
-
---------------------------------------------------------------------------------
-
-via: https://www.ostechnix.com/how-to-easily-upload-text-snippets-to-pastebin-like-services-from-commandline/
-
-作者：[SK][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://www.ostechnix.com/author/sk/
-[b]: https://github.com/lujun9972
-[1]: http://wgetpaste.zlin.dk/
-[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
-[3]: http://www.ostechnix.com/wp-content/uploads/2018/12/wgetpaste-3.png
-[4]: http://www.ostechnix.com/wp-content/uploads/2018/12/wgetpaste-4.png
-[5]: http://wgetpaste.zlin.dk/zlin.conf
-[6]: http://wgetpaste.zlin.dk/wgetpaste.example
diff --git a/sources/tech/20190217 Install Android 8.1 Oreo on Linux To Run Apps - Games.md b/sources/tech/20190217 Install Android 8.1 Oreo on Linux To Run Apps - Games.md
deleted file mode 100644
index f20d24e5cf..0000000000
--- a/sources/tech/20190217 Install Android 8.1 Oreo on Linux To Run Apps - Games.md
+++ /dev/null
@@ -1,208 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (robsean)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Install Android 8.1 Oreo on Linux To Run Apps & Games)
-[#]: via: (https://fosspost.org/tutorials/install-android-8-1-oreo-on-linux)
-[#]: author: (Python Programmer;Open Source Software Enthusiast. Worked On Developing A Lot Of Free Software. The Founder Of Foss Post;Foss Project. Computer Science Major. )
-
-Install Android 8.1 Oreo on Linux To Run Apps & Games
-======
-
-
-
-[android x86][1] is a free and an open source project to port the android system made by Google from the ARM architecture to the x86 architecture, which allow users to run the android system on their desktop machines to enjoy all android functionalities + Apps & games.
-
-The android x86 project finished porting the android 8.1 Oreo system to the x86 architecture few weeks ago. In this post, we’ll explain how to install it on your Linux system so that you can use your android apps and games any time you want.
-
-### Installing Android x86 8.1 Oreo on Linux
-
-#### Preparing the Environment
-
-First, let’s download the android x86 8.1 Oreo system image. You can download it from [this page][2], just click on the “View” button under the android-x86_64-8.1-r1.iso file.
-
-We are going to use QEMU to run android x86 on our Linux system. QEMU is a very good emulator software, which is also free and open source, and is available in all the major Linux distributions repositories.
-
-To install QEMU on Ubuntu/Linux Mint/Debian:
-
-```
-sudo apt-get install qemu qemu-kvm libvirt-bin
-```
-
-To install QEMU on Fedora:
-
-```
-sudo dnf install qemu qemu-kvm
-```
-
-For other distributions, just search for the qemu and qemu-kvm packages and install them.
-
-After you have installed QEMU, we’ll need to run the following command to create the android.img file, which will be like some sort of an allocated disk space just for the android system. All android files and system will be inside that image file:
-
-```
-qemu-img create -f qcow2 android.img 15G
-```
-
-Here we are saying that we want to allocate a maximum of 15GB for android, but you can change it to any size you want (make sure it’s at least bigger than 5GB).
-
-Now, to start running the android system for the first time, run:
-
-```
-sudo qemu-system-x86_64 -m 2048 -boot d -enable-kvm -smp 3 -net nic -net user -hda android.img -cdrom /home/mhsabbagh/android-x86_64-8.1-r1.iso
-```
-
-Replace /home/mhsabbagh/android-x86_64-8.1-r1.iso with the path of the file that you downloaded from the android x86 website. For explaination of other options we are using here, you may refer to [this article][3].
-
-After you run the above command, the android system will start:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 39 android 8.1 oreo on linux][4]
-
-#### Installing the System
-
-From this window, choose “Advanced options”, which should lead to the following menu, from which you should choose “Auto_installation” as follows:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 41 android 8.1 oreo on linux][5]
-
-After that, the installer will just tell you about whether you want to continue or not, choose Yes:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 43 android 8.1 oreo on linux][6]
-
-And the installation will carry on without any further instructions from you:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 45 android 8.1 oreo on linux][7]
-
-Finally you’ll receive this message, which indicates that you have successfully installed android 8.1:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 47 android 8.1 oreo on linux][8]
-
-For now, just close the QEMU window completely.
-
-#### Booting and Using Android 8.1 Oreo
-
-Now that the android system is fully installed in your android.img file, you should use the following QEMU command to start it instead of the previous one:
-
-```
-sudo qemu-system-x86_64 -m 2048 -boot d -enable-kvm -smp 3 -net nic -net user -hda android.img
-```
-
-Notice that all we did was that we just removed the -cdrom option and its argument. This is to tell QEMU that we no longer want to boot from the ISO file that we downloaded, but from the installed android system.
-
-You should see the android booting menu now:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 49 android 8.1 oreo on linux][9]
-
-Then you’ll be taken to the first preparation wizard, choose your language and continue:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 51 android 8.1 oreo on linux][10]
-
-From here, choose the “Set up as new” option:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 53 android 8.1 oreo on linux][11]
-
-Then android will ask you about if you want to login to your current Google account. This step is optional, but important so that you can use the Play Store later:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 55 android 8.1 oreo on linux][12]
-
-Then you’ll need to accept the terms and conditions:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 57 android 8.1 oreo on linux][13]
-
-Now you can choose your current timezone:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 59 android 8.1 oreo on linux][14]
-
-The system will ask you now if you want to enable any data collection features. If I were you, I’d simply turn them all off like that:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 61 android 8.1 oreo on linux][15]
-
-Finally, you’ll have 2 launcher types to choose from, I recommend that you choose the Launcher3 option and make it the default:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 63 android 8.1 oreo on linux][16]
-
-Then you’ll see your fully-working android system home screen:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 65 android 8.1 oreo on linux][17]
-
-From here now, you can do all the tasks you want; You can use the built-in android apps, or you may browse the settings of your system to adjust it however you like. You may change look and feeling of your system, or you can run Chrome for example:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 67 android 8.1 oreo on linux][18]
-
-You may start installing some apps like WhatsApp and others from the Google Play store for your own use:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 69 android 8.1 oreo on linux][19]
-
-You can now do whatever you want with your system. Congratulations!
-
-### How to Easily Run Android 8.1 Oreo Later
-
-We don’t want to always have to open the terminal window and write that long QEMU command to run the android system, but we want to run it in just 1 click whenever we need that.
-
-To do this, we’ll create a new file under /usr/share/applications called android.desktop with the following command:
-
-```
-sudo nano /usr/share/applications/android.desktop
-```
-
-And paste the following contents inside it (Right click and then paste):
-
-```
-[Desktop Entry]
-Name=Android 8.1
-Comment=Run Android 8.1 Oreo on Linux using QEMU
-Icon=phone
-Exec=bash -c 'pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY qemu-system-x86_64 -m 2048 -boot d -enable-kvm -smp 3 -net nic -net user -hda /home/mhsabbagh/android.img'
-Terminal=false
-Type=Application
-StartupNotify=true
-Categories=GTK;
-```
-
-Again, you have to replace /home/mhsabbagh/android.img with the path to the local image on your system. Then save the file (Ctrl + X, then press Y, then Enter).
-
-Notice that we needed to use “pkexec” to run QEMU with root privileges because starting from newer versions, accessing to the KVM technology via libvirt is not allowed for normal users; That’s why it will ask you for the root password each time.
-
-Now, you’ll see the android icon in the applications menu all the time, you can simply click it any time you want to use android and the QEMU program will start:
-
-![Install Android 8.1 Oreo on Linux To Run Apps & Games 71 android 8.1 oreo on linux][20]
-
-### Conclusion
-
-We showed you how install and run android 8.1 Oreo on your Linux system. From now on, it should be much easier on you to do your android-based tasks without some other software like Blutsticks and similar methods. Here, you have a fully-working and functional android system that you can manipulate however you like, and if anything goes wrong, you can simply nuke the image file and run the installation all over again any time you want.
-
-Have you tried android x86 before? How was your experience with it?
-
-
---------------------------------------------------------------------------------
-
-via: https://fosspost.org/tutorials/install-android-8-1-oreo-on-linux
-
-作者：[Python Programmer;Open Source Software Enthusiast. Worked On Developing A Lot Of Free Software. The Founder Of Foss Post;Foss Project. Computer Science Major.][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]:
-[b]: https://github.com/lujun9972
-[1]: http://www.android-x86.org/
-[2]: http://www.android-x86.org/download
-[3]: https://fosspost.org/tutorials/use-qemu-test-operating-systems-distributions
-[4]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-16.png?resize=694%2C548&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 40 android 8.1 oreo on linux)
-[5]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-15.png?resize=673%2C537&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 42 android 8.1 oreo on linux)
-[6]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-14.png?resize=769%2C469&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 44 android 8.1 oreo on linux)
-[7]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-13.png?resize=767%2C466&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 46 android 8.1 oreo on linux)
-[8]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-12.png?resize=750%2C460&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 48 android 8.1 oreo on linux)
-[9]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-11.png?resize=754%2C456&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 50 android 8.1 oreo on linux)
-[10]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-10.png?resize=850%2C559&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 52 android 8.1 oreo on linux)
-[11]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-09.png?resize=850%2C569&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 54 android 8.1 oreo on linux)
-[12]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-08.png?resize=850%2C562&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 56 android 8.1 oreo on linux)
-[13]: https://i2.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-07-1.png?resize=850%2C561&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 58 android 8.1 oreo on linux)
-[14]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-06.png?resize=850%2C569&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 60 android 8.1 oreo on linux)
-[15]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-05.png?resize=850%2C559&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 62 android 8.1 oreo on linux)
-[16]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-04.png?resize=850%2C553&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 64 android 8.1 oreo on linux)
-[17]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-03.png?resize=850%2C571&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 66 android 8.1 oreo on linux)
-[18]: https://i1.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-02.png?resize=850%2C555&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 68 android 8.1 oreo on linux)
-[19]: https://i2.wp.com/fosspost.org/wp-content/uploads/2019/02/Android-8.1-Oreo-on-Linux-01.png?resize=850%2C557&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 70 android 8.1 oreo on linux)
-[20]: https://i0.wp.com/fosspost.org/wp-content/uploads/2019/02/Screenshot-at-2019-02-17-1539.png?resize=850%2C557&ssl=1 (Install Android 8.1 Oreo on Linux To Run Apps & Games 72 android 8.1 oreo on linux)
diff --git a/sources/tech/20190225 Netboot a Fedora Live CD.md b/sources/tech/20190225 Netboot a Fedora Live CD.md
deleted file mode 100644
index f2ca6bb346..0000000000
--- a/sources/tech/20190225 Netboot a Fedora Live CD.md
+++ /dev/null
@@ -1,187 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (robsean)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Netboot a Fedora Live CD)
-[#]: via: (https://fedoramagazine.org/netboot-a-fedora-live-cd/)
-[#]: author: (Gregory Bartholomew https://fedoramagazine.org/author/glb/)
-
-Netboot a Fedora Live CD
-======
-
-
-
-[Live CDs][1] are useful for many tasks such as:
-
- * installing the operating system to a hard drive
- * repairing a boot loader or performing other rescue-mode operations
- * providing a consistent and minimal environment for web browsing
- * …and [much more][2].
-
-
-
-As an alternative to using DVDs and USB drives to store your Live CD images, you can upload them to an [iSCSI][3] server where they will be less likely to get lost or damaged. This guide shows you how to load your Live CD images onto an iSCSI server and access them with the [iPXE][4] boot loader.
-
-### Download a Live CD Image
-
-```
-$ MY_RLSE=27
-$ MY_LIVE=$(wget -q -O - https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/$MY_RLSE/Workstation/x86_64/iso | perl -ne '/(Fedora[^ ]*?-Live-[^ ]*?\.iso)(?{print $^N})/;')
-$ MY_NAME=fc$MY_RLSE
-$ wget -O $MY_NAME.iso https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/$MY_RLSE/Workstation/x86_64/iso/$MY_LIVE
-```
-
-The above commands download the Fedora-Workstation-Live-x86_64-27-1.6.iso Fedora Live image and save it as fc27.iso. Change the value of MY_RLSE to download other archived versions. Or you can browse to to download the latest Fedora live image. Versions prior to 21 used different naming conventions, and must be [downloaded manually here][5]. If you download a Live CD image manually, set the MY_NAME variable to the basename of the file without the extension. That way the commands in the following sections will reference the correct file.
-
-### Convert the Live CD Image
-
-Use the livecd-iso-to-disk tool to convert the ISO file to a disk image and add the netroot parameter to the embedded kernel command line:
-
-```
-$ sudo dnf install -y livecd-tools
-$ MY_SIZE=$(du -ms $MY_NAME.iso | cut -f 1)
-$ dd if=/dev/zero of=$MY_NAME.img bs=1MiB count=0 seek=$(($MY_SIZE+512))
-$ MY_SRVR=server-01.example.edu
-$ MY_RVRS=$(echo $MY_SRVR | tr '.' "\n" | tac | tr "\n" '.' | cut -b -${#MY_SRVR})
-$ MY_LOOP=$(sudo losetup --show --nooverlap --find $MY_NAME.img)
-$ sudo livecd-iso-to-disk --format --extra-kernel-args netroot=iscsi:$MY_SRVR:::1:iqn.$MY_RVRS:$MY_NAME $MY_NAME.iso $MY_LOOP
-$ sudo losetup -d $MY_LOOP
-```
-
-### Upload the Live Image to your Server
-
-Create a directory on your iSCSI server to store your live images and then upload your modified image to it.
-
-**For releases 21 and greater:**
-
-```
-$ MY_FLDR=/images
-$ scp $MY_NAME.img $MY_SRVR:$MY_FLDR/
-```
-
-**For releases prior to 21:**
-
-```
-$ MY_FLDR=/images
-$ MY_LOOP=$(sudo losetup --show --nooverlap --find --partscan $MY_NAME.img)
-$ sudo tune2fs -O ^has_journal ${MY_LOOP}p1
-$ sudo e2fsck ${MY_LOOP}p1
-$ sudo dd status=none if=${MY_LOOP}p1 | ssh $MY_SRVR "dd of=$MY_FLDR/$MY_NAME.img"
-$ sudo losetup -d $MY_LOOP
-```
-
-### Define the iSCSI Target
-
-Run the following commands on your iSCSI server:
-
-```
-$ sudo -i
-# MY_NAME=fc27
-# MY_FLDR=/images
-# MY_SRVR=`hostname`
-# MY_RVRS=$(echo $MY_SRVR | tr '.' "\n" | tac | tr "\n" '.' | cut -b -${#MY_SRVR})
-# cat << END > /etc/tgt/conf.d/$MY_NAME.conf
-
- backing-store $MY_FLDR/$MY_NAME.img
- readonly 1
- allow-in-use yes
-
-END
-# tgt-admin --update ALL
-```
-
-### Create a Bootable USB Drive
-
-The [iPXE][4] boot loader has a [sanboot][6] command you can use to connect to and start the live images hosted on your iSCSI server. It can be compiled in many different [formats][7]. The format that works best depends on the type of hardware you’re running. As an example, the following instructions show how to [chain load][8] iPXE from [syslinux][9] on a USB drive.
-
-First, download iPXE and build it in its lkrn format. This should be done as a normal user on a workstation:
-
-```
-$ sudo dnf install -y git
-$ git clone http://git.ipxe.org/ipxe.git $HOME/ipxe
-$ sudo dnf groupinstall -y "C Development Tools and Libraries"
-$ cd $HOME/ipxe/src
-$ make clean
-$ make bin/ipxe.lkrn
-$ cp bin/ipxe.lkrn /tmp
-```
-
-Next, prepare a USB drive with a MSDOS partition table and a FAT32 file system. The below commands assume that you have already connected the USB drive to be formatted. **Be careful that you do not format the wrong drive!**
-
-```
-$ sudo -i
-# dnf install -y parted util-linux dosfstools
-# echo; find /dev/disk/by-id ! -regex '.*-part.*' -name 'usb-*' -exec readlink -f {} \; | xargs -i bash -c "parted -s {} unit MiB print | perl -0 -ne '/^Model: ([^(]*).*\n.*?([0-9]*MiB)/i && print \"Found: {} = \$2 \$1\n\"'"; echo; read -e -i "$(find /dev/disk/by-id ! -regex '.*-part.*' -name 'usb-*' -exec readlink -f {} \; -quit)" -p "Drive to format: " MY_USB
-# umount $MY_USB?
-# wipefs -a $MY_USB
-# parted -s $MY_USB mklabel msdos mkpart primary fat32 1MiB 100% set 1 boot on
-# mkfs -t vfat -F 32 ${MY_USB}1
-```
-
-Finally, install syslinux on the USB drive and configure it to chain load iPXE:
-
-```
-# dnf install -y syslinux-nonlinux
-# syslinux -i ${MY_USB}1
-# dd if=/usr/share/syslinux/mbr.bin of=${MY_USB}
-# MY_MNT=$(mktemp -d)
-# mount ${MY_USB}1 $MY_MNT
-# MY_NAME=fc27
-# MY_SRVR=server-01.example.edu
-# MY_RVRS=$(echo $MY_SRVR | tr '.' "\n" | tac | tr "\n" '.' | cut -b -${#MY_SRVR})
-# cat << END > $MY_MNT/syslinux.cfg
-ui menu.c32
-default $MY_NAME
-timeout 100
-menu title SYSLINUX
-label $MY_NAME
- menu label ${MY_NAME^^}
- kernel ipxe.lkrn
- append dhcp && sanboot iscsi:$MY_SRVR:::1:iqn.$MY_RVRS:$MY_NAME
-END
-# cp /usr/share/syslinux/menu.c32 $MY_MNT
-# cp /usr/share/syslinux/libutil.c32 $MY_MNT
-# cp /tmp/ipxe.lkrn $MY_MNT
-# umount ${MY_USB}1
-```
-
-You should be able to use this same USB drive to netboot additional iSCSI targets simply by editing the syslinux.cfg file and adding additional menu entries.
-
-This is just one method of loading iPXE. You could install syslinux directly on your workstation. Another option is to compile iPXE as an EFI executable and place it directly in your [ESP][10]. Yet another is to compile iPXE as a PXE loader and place it on your TFTP server to be referenced by DHCP. The best option depends on your environment.
-
-### Final Notes
-
- * You may want to add the –filename \EFI\BOOT\grubx64.efi parameter to the sanboot command if you compile iPXE in its EFI format.
- * It is possible to create custom live images. Refer to [Creating and using live CD][11] for more information.
- * It is possible to add the –overlay-size-mb and –home-size-mb parameters to the livecd-iso-to-disk command to create live images with persistent storage. However, if you have multiple concurrent users, you’ll need to set up your iSCSI server to manage separate per-user writeable overlays. This is similar to what was shown in the “[How to Build a Netboot Server, Part 4][12]” article.
- * The live images support a persistenthome option on their kernel command line (e.g. persistenthome=LABEL=HOME). Used together with CHAP-authenticated iSCSI targets, the persistenthome option provides an interesting alternative to NFS for centralized home directories.
-
-
-
-
---------------------------------------------------------------------------------
-
-via: https://fedoramagazine.org/netboot-a-fedora-live-cd/
-
-作者：[Gregory Bartholomew][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://fedoramagazine.org/author/glb/
-[b]: https://github.com/lujun9972
-[1]: https://en.wikipedia.org/wiki/Live_CD
-[2]: https://en.wikipedia.org/wiki/Live_CD#Uses
-[3]: https://en.wikipedia.org/wiki/ISCSI
-[4]: https://ipxe.org/
-[5]: https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/https://dl.fedoraproject.org/pub/archive/fedora/linux/releases/
-[6]: http://ipxe.org/cmd/sanboot/
-[7]: https://ipxe.org/appnote/buildtargets#boot_type
-[8]: https://en.wikipedia.org/wiki/Chain_loading
-[9]: https://www.syslinux.org/wiki/index.php?title=SYSLINUX
-[10]: https://en.wikipedia.org/wiki/EFI_system_partition
-[11]: https://docs.fedoraproject.org/en-US/quick-docs/creating-and-using-a-live-installation-image/#proc_creating-and-using-live-cd
-[12]: https://fedoramagazine.org/how-to-build-a-netboot-server-part-4/
diff --git a/sources/tech/20190322 Easy means easy to debug.md b/sources/tech/20190322 Easy means easy to debug.md
deleted file mode 100644
index 4b0b4d52d2..0000000000
--- a/sources/tech/20190322 Easy means easy to debug.md
+++ /dev/null
@@ -1,83 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Easy means easy to debug)
-[#]: via: (https://arp242.net/weblog/easy.html)
-[#]: author: (Martin Tournoij https://arp242.net/)
-
-
-What does it mean for a framework, library, or tool to be “easy”? There are many possible definitions one could use, but my definition is usually that it’s easy to debug. I often see people advertise a particular program, framework, library, file format, or something else as easy because “look with how little effort I can do task X, this is so easy!” That’s great, but an incomplete picture.
-
-You only write software once, but will almost always go through several debugging cycles. With debugging cycle I don’t mean “there is a bug in the code you need to fix”, but rather “I need to look at this code to fix the bug”. To debug code, you need to understand it, so “easy to debug” by extension means “easy to understand”.
-
-Abstractions which make something easier to write often come at the cost of make things harder to understand. Sometimes this is a good trade-off, but often it’s not. In general I will happily spend a little but more effort writing something now if that makes things easier to understand and debug later on, as it’s often a net time-saver.
-
-Simplicity isn’t the only thing that makes programs easier to debug, but it is probably the most important. Good documentation helps too, but unfortunately good documentation is uncommon (note that quality is not measured by word count!)
-
-This is not exactly a novel insight; from the 1974 The Elements of Programming Style by Brian W. Kernighan and P. J. Plauger:
-
-> Everyone knows that debugging is twice as hard as writing a program in the first place. So if you’re as clever as you can be when you write it, how will you ever debug it?
-
-A lot of stuff I see seems to be written “as clever as can be” and is consequently hard to debug. I’ll list a few examples of this pattern below. It’s not my intention to argue that any of these things are bad per se, I just want to highlight the trade-offs in “easy to use” vs. “easy to debug”.
-
- * When I tried running [Let’s Encrypt][1] a few years ago it required running a daemon as root(!) to automatically rewrite nginx files. I looked at the source a bit to understand how it worked and it was all pretty complex, so I was “let’s not” and opted to just pay €10 to the CA mafia, as not much can go wrong with putting a file in /etc/nginx/, whereas a lot can go wrong with complex Python daemons running as root.
-
-(I don’t know the current state/options for Let’s Encrypt; at a quick glance there may be better/alternative ACME clients that suck less now.)
-
- * Some people claim that systemd is easier than SysV init.d scripts because it’s easier to write systemd unit files than it is to write shell scripts. In particular, this is the argument Lennart Poettering used in his [systemd myths][2] post (point 5).
-
-I think is completely missing the point. I agree with Poettering that shell scripts are hard – [I wrote an entire post about that][3] – but by making the interface easier doesn’t mean the entire system becomes easier. Look at [this issue][4] I encountered and [the fix][5] for it. Does that look easy to you?
-
- * Many JavaScript frameworks I’ve used can be hard to fully understand. Clever state keeping logic is great and all, until that state won’t work as you expect, and then you better hope there’s a Stack Overflow post or GitHub issue to help you out.
-
- * Docker is great, right up to the point you get:
-
-```
- ERROR: for elasticsearch Cannot start service elasticsearch:
-oci runtime error: container_linux.go:247: starting container process caused "process_linux.go:258:
-applying cgroup configuration for process caused \"failed to write 898 to cgroup.procs: write
-/sys/fs/cgroup/cpu,cpuacct/docker/b13312efc203e518e3864fc3f9d00b4561168ebd4d9aad590cc56da610b8dd0e/cgroup.procs:
-invalid argument\""
-```
-
-or
-
-```
-ERROR: for elasticsearch Cannot start service elasticsearch: EOF
-```
-
-And … now what?
-
- * Many testing libraries can make things harder to debug. Ruby’s rspec is a good example where I’ve occasionally used the library wrong by accident and had to spend quite a long time figuring out what exactly went wrong (as the errors it gave me were very confusing!)
-
-I wrote a bit more about that in my [Testing isn’t everything][6] post.
-
- * ORM libraries can make database queries a lot easier, at the cost of making things a lot harder to understand once you want to solve a problem.
-
-
-
-
-
---------------------------------------------------------------------------------
-
-via: https://arp242.net/weblog/easy.html
-
-作者：[Martin Tournoij][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://arp242.net/
-[b]: https://github.com/lujun9972
-[1]: https://en.wikipedia.org/wiki/Let%27s_Encrypt
-[2]: http://0pointer.de/blog/projects/the-biggest-myths.html
-[3]: https://arp242.net/weblog/shell-scripting-trap.html
-[4]: https://unix.stackexchange.com/q/185495/33645
-[5]: https://cgit.freedesktop.org/systemd/systemd/commit/?id=6e392c9c45643d106673c6643ac8bf4e65da13c1
-[6]: /weblog/testing.html
-[7]: mailto:martin@arp242.net
-[8]: https://github.com/Carpetsmoker/arp242.net/issues/new
diff --git a/sources/tech/20190513 How To Set Password Complexity On Linux.md b/sources/tech/20190513 How To Set Password Complexity On Linux.md
deleted file mode 100644
index e9a3171c6b..0000000000
--- a/sources/tech/20190513 How To Set Password Complexity On Linux.md
+++ /dev/null
@@ -1,243 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How To Set Password Complexity On Linux?)
-[#]: via: (https://www.2daygeek.com/how-to-set-password-complexity-policy-on-linux/)
-[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
-
-How To Set Password Complexity On Linux?
-======
-
-User management is one of the important task of Linux system administration.
-
-There are many aspect is involved in this and implementing the strong password policy is one of them.
-
-Navigate to the following URL, if you would like to **[generate a strong password on Linux][1]**.
-
-It will Restrict unauthorized access to systems.
-
-By default Linux is secure that everybody know. however, we need to make necessary tweak on this to make it more secure.
-
-Insecure password will leads to breach security. So, take additional care on this.
-
-Navigate to the following URL, if you would like to see the **[password strength and score][2]** of the generated strong password.
-
-In this article, we will teach you, how to implement the best security policy on Linux.
-
-We can use PAM (the “pluggable authentication module”) to enforce password policy On most Linux systems.
-
-The file can be found in the following location.
-
-For Redhat based systems @ `/etc/pam.d/system-auth` and Debian based systems @ `/etc/pam.d/common-password`.
-
-The default password aging details can be found in the `/etc/login.defs` file.
-
-I have trimmed this file for better understanding.
-
-```
-# vi /etc/login.defs
-
-PASS_MAX_DAYS 99999
-PASS_MIN_DAYS 0
-PASS_MIN_LEN 5
-PASS_WARN_AGE 7
-```
-
-**Details:**
-
- * **`PASS_MAX_DAYS:`**` ` Maximum number of days a password may be used.
- * **`PASS_MIN_DAYS:`**` ` Minimum number of days allowed between password changes.
- * **`PASS_MIN_LEN:`**` ` Minimum acceptable password length.
- * **`PASS_WARN_AGE:`**` ` Number of days warning given before a password expires.
-
-
-
-We will show you, how to implement the below eleven password policies in Linux.
-
- * Password Max days
- * Password Min days
- * Password warning days
- * Password history or Deny Re-Used Passwords
- * Password minimum length
- * Minimum upper case characters
- * Minimum lower case characters
- * Minimum digits in password
- * Minimum other characters (Symbols)
- * Account lock – retries
- * Account unlock time
-
-
-
-### What Is Password Max days?
-
-This parameter limits the maximum number of days a password can be used. It’s mandatory for user to change his/her account password before expiry.
-
-If they forget to change, they are not allowed to login into the system. They need to work with admin team to get rid of it.
-
-It can be set in `/etc/login.defs` file. I’m going to set `90 days`.
-
-```
-# vi /etc/login.defs
-
-PASS_MAX_DAYS 90
-```
-
-### What Is Password Min days?
-
-This parameter limits the minimum number of days after password can be changed.
-
-Say for example, if this parameter is set to 15 and user changed password today. Then he won’t be able to change the password again before 15 days from now.
-
-It can be set in `/etc/login.defs` file. I’m going to set `15 days`.
-
-```
-# vi /etc/login.defs
-
-PASS_MIN_DAYS 15
-```
-
-### What Is Password Warning Days?
-
-This parameter controls the password warning days and it will warn the user when the password is going to expires.
-
-A warning will be given to the user regularly until the warning days ends. This can helps user to change their password before expiry. Otherwise we need to work with admin team for unlock the password.
-
-It can be set in `/etc/login.defs` file. I’m going to set `10 days`.
-
-```
-# vi /etc/login.defs
-
-PASS_WARN_AGE 10
-```
-
-**Note:** All the above parameters only applicable for new accounts and not for existing accounts.
-
-### What Is Password History Or Deny Re-Used Passwords?
-
-This parameter keep controls of the password history. Keep history of passwords used (the number of previous passwords which cannot be reused).
-
-When the users try to set a new password, it will check the password history and warn the user when they set the same old password.
-
-It can be set in `/etc/pam.d/system-auth` file. I’m going to set `5` for history of password.
-
-```
-# vi /etc/pam.d/system-auth
-
-password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok remember=5
-```
-
-### What Is Password Minimum Length?
-
-This parameter keeps the minimum password length. When the users set a new password, it will check against this parameter and warn the user if they try to set the password length less than that.
-
-It can be set in `/etc/pam.d/system-auth` file. I’m going to set `12` character for minimum password length.
-
-```
-# vi /etc/pam.d/system-auth
-
-password requisite pam_cracklib.so try_first_pass retry=3 minlen=12
-```
-
-**try_first_pass retry=3** : Allow users to set a good password before the passwd command aborts.
-
-### Set Minimum Upper Case Characters?
-
-This parameter keeps, how many upper case characters should be added in the password. These are password strengthening parameters ,which increase the password strength.
-
-When the users set a new password, it will check against this parameter and warn the user if they are not including any upper case characters in the password.
-
-It can be set in `/etc/pam.d/system-auth` file. I’m going to set `1` character for minimum password length.
-
-```
-# vi /etc/pam.d/system-auth
-
-password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 ucredit=-1
-```
-
-### Set Minimum Lower Case Characters?
-
-This parameter keeps, how many lower case characters should be added in the password. These are password strengthening parameters ,which increase the password strength.
-
-When the users set a new password, it will check against this parameter and warn the user if they are not including any lower case characters in the password.
-
-It can be set in `/etc/pam.d/system-auth` file. I’m going to set `1` character.
-
-```
-# vi /etc/pam.d/system-auth
-
-password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 lcredit=-1
-```
-
-### Set Minimum Digits In Password?
-
-This parameter keeps, how many digits should be added in the password. These are password strengthening parameters ,which increase the password strength.
-
-When the users set a new password, it will check against this parameter and warn the user if they are not including any digits in the password.
-
-It can be set in `/etc/pam.d/system-auth` file. I’m going to set `1` character.
-
-```
-# vi /etc/pam.d/system-auth
-
-password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 dcredit=-1
-```
-
-### Set Minimum Other Characters (Symbols) In Password?
-
-This parameter keeps, how many Symbols should be added in the password. These are password strengthening parameters ,which increase the password strength.
-
-When the users set a new password, it will check against this parameter and warn the user if they are not including any Symbol in the password.
-
-It can be set in `/etc/pam.d/system-auth` file. I’m going to set `1` character.
-
-```
-# vi /etc/pam.d/system-auth
-
-password requisite pam_cracklib.so try_first_pass retry=3 minlen=12 ocredit=-1
-```
-
-### Set Account Lock?
-
-This parameter controls users failed attempts. It locks user account after reaches the given number of failed login attempts.
-
-It can be set in `/etc/pam.d/system-auth` file.
-
-```
-# vi /etc/pam.d/system-auth
-
-auth required pam_tally2.so onerr=fail audit silent deny=5
-account required pam_tally2.so
-```
-
-### Set Account Unlock Time?
-
-This parameter keeps users unlock time. If the user account is locked after consecutive failed authentications.
-
-It’s unlock the locked user account after reaches the given time. Sets the time (900 seconds = 15 minutes) for which the account should remain locked.
-
-It can be set in `/etc/pam.d/system-auth` file.
-
-```
-# vi /etc/pam.d/system-auth
-
-auth required pam_tally2.so onerr=fail audit silent deny=5 unlock_time=900
-account required pam_tally2.so
-```
-
---------------------------------------------------------------------------------
-
-via: https://www.2daygeek.com/how-to-set-password-complexity-policy-on-linux/
-
-作者：[Magesh Maruthamuthu][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://www.2daygeek.com/author/magesh/
-[b]: https://github.com/lujun9972
-[1]: https://www.2daygeek.com/5-ways-to-generate-a-random-strong-password-in-linux-terminal/
-[2]: https://www.2daygeek.com/how-to-check-password-complexity-strength-and-score-in-linux/
diff --git a/sources/tech/20190711 DevOps for introverted people.md b/sources/tech/20190711 DevOps for introverted people.md
deleted file mode 100644
index b356d5de7d..0000000000
--- a/sources/tech/20190711 DevOps for introverted people.md
+++ /dev/null
@@ -1,73 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (DevOps for introverted people)
-[#]: via: (https://opensource.com/article/19/7/devops-introverted-people)
-[#]: author: (Matthew Broberg https://opensource.com/users/mbbroberg/users/don-watkins/users/shawnhcorey/users/mbbroberg/users/marcobravo)
-
-DevOps for introverted people
-======
-We asked the Opensource.com DevOps team to talk about their experience
-as DevOps introverts and to give DevOps extroverts some advice. Here are
-their answers.
-![Q and A letters][1]
-
-We asked members of our [DevOps team][2] to talk about their experience as introverts and to give extroverts some advice. Before we get into their responses, though, let’s first define the term.
-
-### What does being introverted mean?
-
-Being an introvert is commonly defined as someone who finds it more energy depleting, as opposed to energizing, to be around people. It can be a helpful term when we think about how we recharge: introverted people may require more alone time to recharge, especially after spending a lot of time around groups of people. A big myth about introverts is that they are necessarily shy, but [science suggests][3] that is a separate personality trait.
-
-Introversion and extraversion were popularized by the [Myers Briggs Type Indicators][4] and are now more commonly referred to as two ends of the same [spectrum][5]. Even though it may seem that there are more extroverted people in the world than introverts, psychologists tend to believe that a majority of us fall along the spectrum closer to [ambiverts or introverts][6].
-
-Now, on to the questions and answers.
-
-### What are some techniques DevOps leaders can use to make sure introverts feel like part of the team and increase their willingness to share ideas?
-
-"Everyone is a little different, so it’s important to be observant. Someone from GitLab once told me their philosophy is that if you aren’t offering your opinion, then they’re being exclusionary. If someone isn’t offering an opinion in a meeting, then find ways to include them. **When I know an introvert is interested in a topic we’re meeting about, I’ll ask in advance for written input. A lot of meetings can be avoided by moving the discussion to slack or GitLab where introverts are more willing to engage.** In stand-up, everyone gives an update, and introverts seem to do fine in this context. So we sometimes do the same thing in other meetings just to make sure everyone has time to speak. I also encourage introverts to speak in front of small groups either at work or in the community in order to build those skills." —Dan Barker
-
-"**I think the best thing that anyone ever did for me was to make sure I had the skills necessary to answer the big questions when they came.** As a very young enlisted Air Force member I was giving status briefings to my units’ senior leadership. That required that I have a number of data points available at any given moment as well as the why behind any delays or deviations on the way towards established objectives. That propelled me from a behind the scenes person into being willing to share my opinion and thoughts with others." —Chris Short
-
-"**Lead through culture. Design and try out a ritual for your co-workers.** You can design a smaller weekly ritual for groups or teams or a bigger yearly event for your department or organization. The point is to try something and observe your leadership role in it. Identify gaps or tensions in your culture. Look back at the beliefs and behaviors of teams. Where do you observe tension? What’s missing from your culture? Start with a simple statement 'I see a tension between X and Y'. Or 'My team is missing Z'. Next, flip the gap or tension into a question: write down 3 'How might we’s (HMWs)'." —Catherine Louis
-
-"Introverts are not a different class of people, they are either people who think or wait too much before they share their mind or people who have no idea what's going on. I was one among the first category, I thought too much and sometimes worried about what if my opinion is laughed upon or not entertained or thought otherwise. It was hard coming up of that kind of mindset but it was also eating my chances of learning better things. Once, we were discussing in the team about an implementation issue. My then manager asked me one on one, why I am not participating as I am one of the more experienced people on the team, and I opened up (after I gathered all the power in the universe to say something) saying everything I wanted to say was already shared. He suggested 'I could use a repetition sometimes, as there are many things going on, it would be helpful if you just repeat your thought even if it is discussed'. Well, that was not a very persuasive way but that gave me a bit of confidence that someone at-least wants to hear me.
-
-"Now, the way I used to make people speak in my team, is **I often ask the introvert person for help, even if I know the resolution, and appreciate them in team meetings and discussions to boost up their confidence encouraging them to share more knowledge with the team, by slowly giving them time to come out of their reserved nature**. They may still remain a bit isolated in the outer world but within a team, some emerge a player we can count on." —Abhishek Tamrakar
-
-"My advice to introverts when participating in conferences is to find friends/colleagues who are also attending so you have people to talk to comfortably, reach out prior to the event to schedule some smaller meetings/meals with other attendees (friends, industry contacts, former colleagues, etc.), **be mindful of your exhaustion level and take care of yourself**: skip the social/evening events if you need to recharge, write about your experience in a post-event retrospective." —Elizabeth Joseph
-
-### What are some tips for increasing productivity when working with a teammate who tends to be more of an introvert?
-
-"Productivity is increasingly challenging to really qualify. In many cases, a break from work or a casual conversation can be the spark needed in our creative endeavors. Again, I find slack and GitLab to be very helpful mediums for exchanging ideas and interacting with others when you have introverts on your team. **I also find pair programming to be very useful for most introverts as one on one interactions aren’t usually as taxing but the product quality and efficiency gains are substantial.** However, when an introvert is working alone, everyone on the team should be discouraged from interrupting them. It’s best to send them an email or some non-intrusive medium." —Dan Barker
-
-"Give them great tools for doing and documenting their work. **Enable them to be the best they can be at their job.** Check in with them frequently enough to make sure they’re on the right track but also be mindful it’s a bigger distraction to them than it is more extroverted people." —Chris Short
-
-"**Don’t interrupt me when I am heads down.** Really, don’t. It could take me 2 hours minimally to get my brain back to where I was when I was knee deep in something. It feels painful. Really. Instead, email me and ask me to come to a place where there is a whiteboard. Share the problem from the customer's point of view—draw it—not from your point of view. I may have dozens of customer issues niggling in the back of my brain. If your issues sound like 'make me look good to my upper management', it will get less attention from me than the true customer's issues I already have. Draw a picture. Give me time to think. Make sure there is more than one marker in case I am ready to share. Be prepared that your hypothesis about the problem is completely wrong." —Catherine Louis
-
-"Appreciation and encouragement is the way out, appreciation may not be an appraisal, but an appreciation that encourages people to feel comfortable in presence of more than one living entities, **so that everyone feels heard and not laughed or underrated**." —Abhishek Tamrakar
-
-### Final thoughts
-
-The biggest takeaway from our conversations on introverted DevOps enthusiasts is one of equity: Treat people as they need to be treated, and ask people to treat you as you want to be treated. Whether you are extroverted or introverted, we all need to respect the fact that we do not all experience the world in the same way. Our colleagues deserve the space they need to get the work done, and knowing how to support them starts with a discussion on their needs. Our differences are what make our communities so special and it makes our work more useful for more people. The most effective way to communicate with others is to communicate in a style that works well for both of you.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/7/devops-introverted-people
-
-作者：[Matthew Broberg][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/mbbroberg/users/don-watkins/users/shawnhcorey/users/mbbroberg/users/marcobravo
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc_QandAorange_520x292_0311LL.png?itok=qa3hHSou (Q and A letters)
-[2]: https://opensource.com/devops-team
-[3]: https://www.inc.com/melanie-curtin/are-you-shy-or-introverted-science-says-this-is-1-primary-difference.html
-[4]: https://www.myersbriggs.org/my-mbti-personality-type/mbti-basics/extraversion-or-introversion.htm?bhcp=1
-[5]: https://lifehacker.com/lets-quit-it-with-the-introvert-extrovert-nonsense-1713772952
-[6]: https://www.psychologytoday.com/us/blog/the-gen-y-guide/201710/the-majority-people-are-not-introverts-or-extroverts
diff --git a/sources/tech/20190724 How to make an old computer useful again.md b/sources/tech/20190724 How to make an old computer useful again.md
deleted file mode 100644
index 68748a93b6..0000000000
--- a/sources/tech/20190724 How to make an old computer useful again.md
+++ /dev/null
@@ -1,192 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to make an old computer useful again)
-[#]: via: (https://opensource.com/article/19/7/how-make-old-computer-useful-again)
-[#]: author: (Howard Fosdick https://opensource.com/users/howtechhttps://opensource.com/users/don-watkinshttps://opensource.com/users/suehlehttps://opensource.com/users/aseem-sharmahttps://opensource.com/users/sethhttps://opensource.com/users/marcobravohttps://opensource.com/users/dragonbitehttps://opensource.com/users/don-watkinshttps://opensource.com/users/jamesfhttps://opensource.com/users/seth)
-
-How to make an old computer useful again
-======
-Refurbish an old machine with these step-by-step instructions.
-![Person typing on a 1980's computer][1]
-
-Have an old computer gathering dust in your basement? Why not put it to use? A backup machine could come in handy if your primary computer fails and you want to be online with a larger screen than your smartphone. Or it could act as a cheap secondary computer shared by the family. You could even make it into a retro gaming box.
-
-You can take any computer up to a dozen years old and—with the right software—perform many of the same tasks you can with new machines. Open source software is the key.
-
-I've refurbished computers for two decades, and in this article, I'll share how I do it. We're talking about dual-core laptops and desktops between five and 12 years old.
-
-### Verify the hardware
-
-Step one is to verify that your hardware all works. Overlooking a problem here could cause you big headaches later.
-
-Dust kills electronics, so open up the box and clean out the dirt. [Compressed air][2] comes in handy. Be careful that you're [grounded][3] whenever you touch the machine. And _don't_ rub anything with a cleaning cloth. Even a static shock so small you won't feel it can destroy circuitry.
-
-Then close the clean computer and verify that all the hardware works. Test:
-
- * Memory
- * Disk
- * Motherboard
- * Peripherals (DVD drive, USB ports, sound, etc.)
-
-
-
-Run any diagnostic tests in the computer's boot panels (the [UEFI][4] or [BIOS][5] panels). [This list][6] tells you which program function (PF) key to press to access those panels for your computer.
-
-Free resource kits like [Hirens BootCD][7] or [Ultimate Boot CD][8] enable you to test what your boot panels don't. They contain hundreds of testing programs; all are free, but not all are open source. You don't have to install anything to run these kits because they'll boot from a USB thumb drive or DVD drive.
-
-Be thorough! Run the extended tests for memory and disk—not just the short tests. Let them run overnight. That's the only way to catch transient (sporadic) errors.
-
-If you find problems, my [Quick guide to fixing hardware][9] will help you solve the most common hardware issues.
-
-### Select the software
-
-The key to refurbishing is to install software appropriate for the hardware resources you have. The three essential hardware resources are:
-
- 1. Processor (number of cores and speed)
- 2. Memory
- 3. Video memory
-
-
-
-You can identify your computer's resources in its boot-time UEFI/BIOS panels. Write down your findings so that you don't forget them. Then, look up your processor at [CPU Benchmark][10]. That website gives you background on your CPU plus a CPU Mark that indicates its performance.
-
-Now that you know your hardware's power, you're ready to select software that it can efficiently run. Your software choices are divided into four critical areas:
-
- 1. Operating system (OS)
- 2. Desktop environment (DE)
- 3. Browser
- 4. Applications
-
-
-
-A good Linux distribution covers all four. Don't be tempted to run an unsupported version of Windows like 8, Vista, or XP just because it's already on the computer! The [risk][11] of malware is too great. You're much better off with a more virus-resistant, up-to-date operating system.
-
-How about Windows 7? [Extended support][12] ends January 14, 2020, meaning you get security fixes only until that date. After that, zilch. Now is the perfect time to migrate off Windows 7.
-
-Linux's big benefit is that it offers [many distros][13] specifically designed for older hardware. Plus, its design decouples [DEs][14] from the OS, so you can mix and match the two. This is important because DEs heavily impact low-end system performance. (With Windows and MacOS, the OS version you run dictates the DE.)
-
-Other Linux advantages: Its thousands of apps are free and open source, so you don't have to worry about activation and licensing. And Linux is portable. You can copy, move, or clone the OS and applications across partitions, disks, devices, or computers. (Windows binds itself to the computer it's installed on via its Registry.)
-
-### What can your refurbished computer do?
-
-We're talking dual-core machines dating from about 2006 to 2013, especially [Intel Core 2][15] CPUs and [AMD Athlon 64 X2][16] family processors. Most have a [CPU Mark][10] of between 1,000 and 4,000. You can often pick up these machines for a song, yet they're still powerful enough to run lightweight Linux software.
-
-One caution: be sure your computer has at least 2GB of memory. Upgrade the RAM if you have to. End users on my refurbished machines typically use between 0.5 and 2GB of RAM (exclusive of data buffering); rarely do they go over 2 gig. So if you can bump memory to 2GB, your system won't be forced to _swap_, or substitute disk for memory. That's critical for good performance.
-
-For example, I removed 1GB RAM from the decade-old rebuild I'm writing this article on, which dropped memory down to 1GB. The machine slowed to a crawl. Web surfing and other tasks became frustrating, even painful. I popped the memory stick back in and, with 2GB RAM, the desktop instantly reverted to its usable self.
-
-With a 2 gig dual-core computer, most people can do whatever they want, so long as they run a lightweight distro and browser. You can web surf, email, edit documents, do spreadsheets, watch YouTube videos, bid on eBay auctions, post on social media, listen to podcasts, view photo collections, manage home finance and personal scheduling, play games, and more.
-
-### Limitations
-
-What can't these older computers do? Their concurrency is less than state-of-the-art machines. So run a fast browser and block ads, because that's what slows down web surfing. If your virtual private network (VPN) can block ads for you and offload that work from your processor, that's ideal. Disable autoplay of videos, Flash, and animation. Surf with a couple of tabs open rather than 20. Install a browser extension so you can toggle JavaScript.
-
-Direct the processors to what you're working on; don't keep a ton of apps open or run lots of stuff in the background. High-end graphics and video editing may be slow. Virtual machine hosting is out.
-
-How about games? The open source software repositories offer literally thousands of games. That's why I listed video memory as one of the three essential hardware resources. If your box doesn't have a video card, it likely has only 32 or 64MB of VRAM. Bump that to 256 or 512MB by adding a video card, and you'll find that processor-intensive games run much better. [Here's how][17] to see how much VRAM your computer has. Be sure to get a card that fits your computer's [video slot][18] (AGP, PCI-Express, or PCI) and has the right [cable connector][19] (VGA, DVI, or HDMI).
-
-#### What about Windows compatibility?
-
-People often ask about Windows compatibility. First, there's a [Linux equivalent][20] for every Windows program.
-
-Second, if you really must run a specific Windows program, you can usually do that on Linux using [Wine][21]. Look up your application in the [Wine database][22] to verify it runs under Wine and learn any special install tricks. Then the auxiliary tools [Winetricks][23] or [PlayOnLinux][24] will help you with installation and setup.
-
-Wine's other benefit is that it runs programs from old Windows versions like Vista, XP, ME/98/95, and 3.1. I know a guy who set up a fantastic game box running his old XP games. You can even run thousands of [free DOS programs][25] using [DOSBox.][26] One caution: if Windows programs can run, so can Windows [viruses][27]. You must protect your Wine environment inside Linux just as you would any other Windows environment.
-
-How about compatibility with Microsoft Office? I use LibreOffice and routinely edit and exchange Word and Excel files without problems. You must, however, avoid using obscure or specialized features.
-
-### Which distro?
-
-Assuming Linux is the OS, you need to select a DE, browser, and applications. The easy way to do this is to install a distribution that bundles everything you need.
-
-Remember that you can try out different distros without installing anything by booting from a [live USB][28] thumb drive or DVD. [Here's how to create a bootable Linux][29] from within Linux or Windows.
-
-I rebuild computers for charity, so I can't assume any knowledge on the part of my users. I need a distro with these traits:
-
- * User-friendly
- * Lightweight interface
- * Bundles lightweight apps
- * Big repository
- * Solid track record
- * Large user community with an active forum
- * Stability through long-term support releases (not rolling releases)
- * Prioritizes reliability over cutting-edge features
- * Configurable by a GUI rather than by text files
-
-
-
-Many distros fulfill these criteria. The three I've successfully deployed are [Mint/Xfce][30], [Xubuntu,][31] and [Lubuntu][32]. The first two use the Xfce desktop environment, while the latter runs LXQt. These DEs [use less][33] processor and memory resources than alternatives like GNOME, Unity, KDE, MATE, and Cinnamon.
-
-Xfce and LXQt are very easy to use. My clients have never seen Linux before, yet they have no trouble using these simple, menu-driven interfaces.
-
-It's vital to run the fastest, most efficient browser on older equipment. [Many feel][34] Chromium wins the browser race. I also install Firefox Quantum because people are familiar with it and [its performance][35] rivals [that of Chromium][36]. I toss in Opera because it's speedy and has some unique features, like integrated ad-blocking and a free [virtual private network][37]. Opera is free but not open source.
-
-Whatever browser you use, block ads and trackers! Minimize browser overhead. And don't allow videos or Flash to run without your explicit say-so.
-
-For applications, I rely on the lightweight apps bundled with Mint/Xfce, Xubuntu, and Lubuntu. They address every possible need.
-
-### Go for it
-
-Will you be happy with your rebuild? The computers I've been using lately are both over a decade old. One has an Intel dual-core processor ([eMachines T5274a][38]) while the other features an AMD Athlon 64 x2 processor ([HP dc5750][39]). Both have 2 gig memory. They're as effective for my office workload as my quad-core i5 with 16GB RAM. The only function I miss when using them is the ability to host virtual machines.
-
-We live in an amazing era. You can take a five- to 12-year-old computer and, with a little effort, restore it to practical use. What could be more fun?
-
-Having recently co-authored a book about building things with the Raspberry Pi ( Raspberry Pi Hacks...
-
-I can see the brightness of curiosity in my six year old niece Shuchi's eyes when she explores a...
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/7/how-make-old-computer-useful-again
-
-作者：[Howard Fosdick][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/howtechhttps://opensource.com/users/don-watkinshttps://opensource.com/users/suehlehttps://opensource.com/users/aseem-sharmahttps://opensource.com/users/sethhttps://opensource.com/users/marcobravohttps://opensource.com/users/dragonbitehttps://opensource.com/users/don-watkinshttps://opensource.com/users/jamesfhttps://opensource.com/users/seth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/1980s-computer-yearbook.png?itok=eGOYEKK- (Person typing on a 1980's computer)
-[2]: https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=compressed+air+for+computers&rh=i%3Aaps%2Ck%3Acompressed+air+for+computers
-[3]: https://www.wikihow.com/Ground-Yourself-to-Avoid-Destroying-a-Computer-with-Electrostatic-Discharge
-[4]: https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface
-[5]: http://en.wikipedia.org/wiki/BIOS
-[6]: http://www.disk-image.com/faq-bootmenu.htm
-[7]: http://www.hirensbootcd.org/download/
-[8]: http://www.ultimatebootcd.com/
-[9]: http://www.rexxinfo.org/Quick_Guide/Quick_Guide_To_Fixing_Computer_Hardware
-[10]: http://www.cpubenchmark.net/
-[11]: https://askleo.com/unsupported-software-really-mean/
-[12]: http://home.bt.com/tech-gadgets/computing/windows-7/windows-7-support-end-11364081315419
-[13]: https://fossbytes.com/best-lightweight-linux-distros/
-[14]: http://en.wikipedia.org/wiki/Desktop_environment
-[15]: https://en.wikipedia.org/wiki/Intel_Core_2
-[16]: https://en.wikipedia.org/wiki/Athlon_64_X2
-[17]: http://www.cyberciti.biz/faq/howto-find-linux-vga-video-card-ram/
-[18]: https://www.onlinecomputertips.com/support-categories/hardware/493-pci-vs-agp-vs-pci-express-video-cards/
-[19]: https://silentpc.com/articles/video-connectors
-[20]: http://wiki.linuxquestions.org/wiki/Linux_software_equivalent_to_Windows_software
-[21]: https://en.wikipedia.org/wiki/Wine_%28software%29
-[22]: https://appdb.winehq.org/
-[23]: https://en.wikipedia.org/wiki/Winetricks
-[24]: https://en.wikipedia.org/wiki/PlayOnLinux
-[25]: https://archive.org/details/softwarelibrary_msdos
-[26]: https://en.wikipedia.org/wiki/DOSBox
-[27]: https://wiki.winehq.org/FAQ#Is_Wine_malware-compatible.3F
-[28]: https://www.howtogeek.com/howto/linux/create-a-bootable-ubuntu-usb-flash-drive-the-easy-way/
-[29]: https://unetbootin.github.io/
-[30]: https://linuxmint.com/
-[31]: https://xubuntu.org/
-[32]: https://lubuntu.me/
-[33]: https://www.makeuseof.com/tag/best-lean-linux-desktop-environment-lxde-vs-xfce-vs-mate/
-[34]: https://www.zdnet.com/article/chrome-is-the-most-popular-web-browser-of-all/
-[35]: https://www.laptopmag.com/articles/firefox-quantum-vs-chrome
-[36]: https://www.zdnet.com/article/just-how-fast-is-firefox-quantum/
-[37]: http://en.wikipedia.org/wiki/Virtual_private_network
-[38]: https://www.cnet.com/products/emachines-t5274/specs/
-[39]: https://community.spiceworks.com/products/7727-hewlett-packard-dc5750-microtower
diff --git a/sources/tech/20190725 24 sysadmin job interview questions you should know.md b/sources/tech/20190725 24 sysadmin job interview questions you should know.md
deleted file mode 100644
index c80bf8f86e..0000000000
--- a/sources/tech/20190725 24 sysadmin job interview questions you should know.md
+++ /dev/null
@@ -1,292 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (24 sysadmin job interview questions you should know)
-[#]: via: (https://opensource.com/article/19/7/sysadmin-job-interview-questions)
-[#]: author: (DirectedSoul https://opensource.com/users/directedsoul)
-
-24 sysadmin job interview questions you should know
-======
-Have a sysadmin job interview coming up? Read this article for some
-questions you might encounter and possible answers.
-![Question and answer.][1]
-
-As a geek who always played with computers, a career after my masters in IT was a natural choice. So, I decided the sysadmin path was the right one. In the process of my career, I have grown quite familiar with the job interview process. Here is a look at what to expect, the general career path, and a set of common questions and my answers to them.
-
-### Typical sysadmin tasks and duties
-
-Organizations need someone who understands the basics of how a system works so that they can keep their data safe, and keep their services running smoothly. You might ask: "Wait, isn’t there more that a sysadmin can do?"
-
-You are right. Now, in general, let’s look at what might be a typical sysadmin’s day-to-day tasks. Depending on their company’s needs and the person’s skill level, a sysadmin’s tasks vary from managing desktops, laptops, networks, and servers, to designing the organization’s IT policies. Sometimes sysadmins are even in charge of purchasing and placing orders for new IT equipment.
-
-Those seeking system administration as their career paths might find it difficult to keep their skills and knowledge up to date, as rapid changes in the IT field are inevitable. The next natural question that arises out of anyone’s mind is how IT professionals keep up with the latest updates and skills.
-
-### Low difficulty questions
-
-Here are some of the more basic questions you will encounter, and my answers:
-
- 1. What are the first five commands you type on a *nix server after login?
-
-
-
-> * **lsblk** to see information on all block devices
-> * **who** to see who is logged into the server
-> * **top** to get a sense of what is running on the server
-> * **df -khT** to view the amount of disk space available on the server
-> * **netstat** to see what TCP network connections are active
->
-
-
- 2. How do you make a process run in the background, and what are the advantages of doing so?
-
-
-
-> You can make a process run in the background by adding the special character **&** at the end of the command. Generally, applications that take too long to execute, and don’t require user interaction are sent to the background so that we can continue our work in the terminal. ([Citation][2])
-
- 3. Is running these commands as root a good or bad idea?
-
-
-
-> Running (everything) as root is bad due to two major issues. The first is _risk_. Nothing prevents you from making a careless mistake when you are logged in as **root**. If you try to change the system in a potentially harmful way, you need to use **sudo**, which introduces a pause (while you’re entering the password) to ensure that you aren’t about to make a mistake.
->
-> The second reason is _security_. Systems are harder to hack if you don’t know the admin user’s login information. Having access to root means you already have one half of the working set of admin credentials.
-
- 4. What is the difference between **rm** and **rm -rf**?
-
-
-
-> The **rm** command by itself only deletes the named files (and not directories). With **-rf** you add two additional features: The **-r**, **-R**, or --**recursive** flag recursively deletes the directory’s contents, including hidden files and subdirectories, and the **-f**, or --**force**, flag makes **rm** ignore nonexistent files, and never prompt for confirmation.
-
- 5. **Compress.tgz** has a file size of approximately 15GB. How can you list its contents, and how do you list them only for a specific file?
-
-
-
-> To list the file’s contents:
->
-> **tar tf archive.tgz**
->
-> To extract a specific file:
->
-> **tar xf archive.tgz filename**
-
-### Medium difficulty questions
-
-Here are some harder questions you might encounter, and my answers:
-
- 6. What is RAID? What is RAID 0, RAID 1, RAID 5, RAID 6, and RAID 10?
-
-
-
-> A RAID (Redundant Array of Inexpensive Disks) is a technology used to increase the performance and/or reliability of data storage. The RAID levels are:
->
-> * RAID 0: Also known as disk striping, which is a technique that breaks up a file, and spreads the data across all of the disk drives in a RAID group. There are no safeguards against failure. ([Citation][3])
-> * RAID 1: A popular disk subsystem that increases safety by writing the same data on two drives. Called _mirroring_, RAID1 does not increase write performance, but read performance may increase up to the sum of each disks’ performance. Also, if one drive fails, the second drive is used, and the failed drive is manually replaced. After replacement, the RAID controller duplicates the contents of the working drive onto the new one.
-> * RAID 5: A disk subsystem that increases safety by computing parity data and increasing speed. RAID 5 does this by interleaving data across three or more drives (striping). Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost.
-> * RAID 6: Which extends RAID 5 by adding another parity block. This level requires a minimum of four disks, and can continue to execute read/write with any two concurrent disk failures. RAID 6 does not have a performance penalty for reading operations, but it does have a performance penalty on write operations because of the overhead associated with parity calculations.
-> * RAID 10: Also known as RAID 1+0, RAID 10 combines disk mirroring and disk striping to protect data. It requires a minimum of four disks, and stripes data across mirrored pairs. As long as one disk in each mirrored pair is functional, data can be retrieved. If two disks in the same mirrored pair fail, all data will be lost because there is no parity in the striped sets. ([Citation][4])
->
-
-
- 7. Which port is used for the **ping** command?
-
-
-
-> The **ping** command uses ICMP. Specifically, it uses ICMP echo requests and ICMP echo reply packets.
->
-> ICMP does not use either UDP or TCP communication services: Instead, it uses raw IP communication services. This means that the ICMP message is carried directly in an IP datagram data field.
-
- 8. What is the difference between a router and a gateway? What is the default gateway?
-
-
-
-> _Router_ describes the general technical function (layer 3 forwarding), or a hardware device intended for that purpose, while _gateway_ describes the function for the local segment (providing connectivity to elsewhere). You could also state that you "set up a router as a gateway." Another term is _hop_, which describes forwarding between subnets.
->
-> The term _default gateway_ is used to mean the router on your LAN, which has the responsibility of being the first point of contact for traffic to computers outside the LAN.
-
- 9. Explain the boot process for Linux.
-
-
-
-> BIOS -> Master Boot Record (MBR) -> GRUB -> the kernel -> init -> runlevel
-
- 10. How do you check the error messages while the server is booting up?
-
-
-
-> Kernel messages are always stored in the kmsg buffer, visible via the **dmesg** command.
->
-> Boot issues and errors call for a system administrator to look into certain important files, in conjunction with particular commands, which are each handled differently by different versions of Linux:
->
-> * **/var/log/boot.log** is the system boot log, which contains all that unfolded during the system boot.
-> * **/var/log/messages** stores global system messages, including the messages logged during system boot.
-> * **/var/log/dmesg** contains kernel ring buffer information.
->
-
-
- 11. What is the difference between a symbolic link and a hard link?
-
-
-
-> A _symbolic_ or _soft link_ is an actual link to the original file, whereas a _hard link_ is a mirror copy of the original file. If you delete the original file, the soft link has no value, because it then points to a non-existent file. In the case of a hard link, it is entirely the opposite. If you delete the original file, the hard link still contains the data from the original file. ([Citation][5])
-
- 12. How do you change kernel parameters? What kernel options might you need to tune?
-
-
-
-> To set the kernel parameters in Unix-like systems, first edit the file **/etc/sysctl.conf**. After making the changes, save the file and run the **sysctl -p** command. This command makes the changes permanent without rebooting the machine
-
- 13. Explain the **/proc** filesystem.
-
-
-
-> The **/proc** filesystem is virtual, and provides detailed information about the kernel, hardware, and running processes. Since **/proc** contains virtual files, it is called the _virtual file system_. These virtual files have unique qualities. Most of them are listed as zero bytes in size.
->
-> Virtual files such as **/proc/interrupts**, **/proc/meminfo**, **/proc/mounts** and **/proc/partitions** provide an up-to-the-moment glimpse of the system’s hardware. Others, such as **/proc/filesystems** and the **/proc/sys** directory provide system configuration information and interfaces.
-
- 14. How do you run a script as another user without their password?
-
-
-
-> For example, if you were editing the sudoers file (such as **/private/etc/sudoers**), you might use **visudo** to add the following:
->
-> [**user1 ALL=(user2) NOPASSWD: /opt/scripts/bin/generate.sh**][2]
-
- 15. What is the UID 0 toor account? Have you been compromised?
-
-
-
-> The toor user is an alternative superuser account, where toor is root spelled backward. It is intended to be used with a non-standard shell, so the default shell for root does not need to change.
->
-> This purpose is important. Shells which are not part of the base distribution, but are instead installed from ports or packages, are installed in **/usr/local/bin**; which, by default, resides on a different file system. If root’s shell is located in **/usr/local/bin** and the file system containing **/usr/local/bin** is not mounted, root could not log in to fix a problem, and the sysadmin would have to reboot into single-user mode to enter the shell’s path.
-
-### Advanced questions
-
-Here are the even more difficult questions you may encounter:
-
- 16. How does **tracert** work and what protocol does it use?
-
-
-
-> The command **tracert**—or **traceroute** depending on the operating system—allows you to see exactly what routers you touch as you move through the chain of connections to your final destination. If you end up with a problem where you can’t connect to or **ping** your final destination, a **tracert** can help in that you can tell exactly where the chain of connections stops. ([Citation][6])
->
-> With this information, you can contact the correct people; whether it be your own firewall, your ISP, your destination’s ISP, or somewhere in the middle. The **tracert** command—like **ping**—uses the ICMP protocol, but also can use the first step of the TCP three-way handshake to send SYN requests for a response.
-
- 17. What is the main advantage of using **chroot**? When and why do we use it? What is the purpose of the **mount /dev**, **mount /proc**, and **mount /sys** commands in a **chroot** environment?
-
-
-
-> An advantage of having a **chroot** environment is that the filesystem is isolated from the physical host, since **chroot** has a separate filesystem inside your filesystem. The difference is that **chroot** uses a newly created root (**/**) as its root directory.
->
-> A **chroot** jail lets you isolate a process and its children from the rest of the system. It should only be used for processes that don’t run as **root**, as **root** users can break out of the jail easily.
->
-> The idea is that you create a directory tree where you copy or link in all of the system files needed for the process to run. You then use the **chroot()** system call to tell it the root directory now exists at the base of this new tree, and then start the process running in that **chroot**’d environment. Since the command then can’t reference paths outside the modified root directory, it can’t perform operations (read, write, etc.) maliciously on those locations. ([Citation][7])
-
- 18. How do you protect your system from getting hacked?
-
-
-
-> By following the principle of least privileges and these practices:
->
-> * Encrypt with public keys, which provides excellent security.
-> * Enforce password complexity.
-> * Understand why you are making exceptions to the rules above.
-> * Review your exceptions regularly.
-> * Hold someone to account for failure. (It keeps you on your toes.) ([Citation][8])
->
-
-
- 19. What is LVM, and what are the advantages of using it?
-
-
-
-> LVM, or Logical Volume Management, uses a storage device management technology that gives users the power to pool and abstract the physical layout of component storage devices for easier and flexible administration. Using the device mapper Linux kernel framework, the current iteration (LVM2) can be used to gather existing storage devices into groups and allocate logical units from the combined space as needed.
-
- 20. What are sticky ports?
-
-
-
-> Sticky ports are one of the network administrator’s best friends and worst headaches. They allow you to set up your network so that each port on a switch only permits one (or a number that you specify) computer to connect on that port, by locking it to a particular MAC address.
-
- 21. Explain port forwarding?
-
-
-
-> When trying to communicate with systems on the inside of a secured network, it can be very difficult to do so from the outside—and with good reason. Therefore, the use of a port forwarding table within the router itself, or other connection management device, can allow specific traffic to automatically forward to a particular destination. For example, if you had a web server running on your network and you wanted to grant access to it from the outside, you would set up port forwarding to port 80 on the server in question. This would mean that anyone entering your IP address in a web browser would connect to the server’s website immediately.
->
-> Please note, it is usually not recommended to allow access to a server from the outside directly into your network.
-
- 22. What is a false positive and false negative in the case of IDS?
-
-
-
-> When the Intrusion Detection System (IDS) device generates an alert for an intrusion which has actually not happened, this is false positive. If the device has not generated any alert and the intrusion has actually happened, this is the case of a false negative.
-
- 23. Explain **:(){ :|:& };:** and how to stop this code if you are already logged into the system?
-
-
-
-> This is a fork bomb. It breaks down as follows:
->
-> * **:()** defines the function, with **:** as the function name, and the empty parenthesis shows that it will not accept any arguments.
-> * **{ }** shows the beginning and end of the function definition.
-> * **:|:** loads a copy of the function **:** into memory, and pipes its output to another copy of the **:** function, which also has to be loaded into memory.
-> * **&** makes the previous item a background process, so that the child processes will not get killed even though the parent gets auto-killed.
-> * **:** at the end executes the function again, and hence the chain reaction begins.
->
-
->
-> The best way to protect a multi-user system is to use Privileged Access Management (PAM) to limit the number of processes a user can use.
->
-> The biggest problem with a fork bomb is the fact it takes up so many processes. So, we have two ways of attempting to fix this if you are already logged into the system. One option is to execute a SIGSTOP command to stop the process, such as:
->
-> **killall -STOP -u user1**
->
-> If you can’t use the command line due to all processes being used, you will have to use **exec** to force it to run:
->
-> **exec killall -STOP -u user1**
->
-> With fork bombs, your best option is preventing them from becoming too big of an issue in the first place
-
- 24. What is OOM killer and how does it decide which process to kill first?
-
-
-
-> If memory is exhaustively used up by processes to the extent that possibly threatens the system’s stability, then the out of memory (OOM) killer comes into the picture.
->
-> An OOM killer first has to select the best process(es) to kill. _Best_ here refers to the process which will free up the maximum memory upon being killed, and is also the least important to the system. The primary goal is to kill the least number of processes to minimize the damage done, and at the same time maximize the amount of memory freed.
->
-> To facilitate this goal, the kernel maintains an oom_score for each of the processes. You can see the oom_score of each of the processes in the **/proc** filesystem under the **pid** directory:
->
-> **$ cat /proc/10292/oom_score**
->
-> The higher the value of oom_score for any process, the higher its likelihood is of being killed by the OOM Killer in an out-of-memory situation. ([Citation][9])
-
-### Conclusion
-
-System administration salaries have a [wide range][10] with some sites mentioning $70,000 to $100,000 a year, depending on the location, the size of the organization, and your education level plus years of experience. In the end, the system administration career path boils down to your interest in working with servers and solving cool problems. Now, I would say go ahead and achieve your dream path.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/7/sysadmin-job-interview-questions
-
-作者：[DirectedSoul][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/directedsoul
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_HowToFish_520x292.png?itok=DHbdxv6H (Question and answer.)
-[2]: https://github.com/trimstray/test-your-sysadmin-skills
-[3]: https://www.waytoeasylearn.com/2016/05/netapp-filer-tutorial.html
-[4]: https://searchstorage.techtarget.com/definition/RAID-10-redundant-array-of-independent-disks
-[5]: https://www.answers.com/Q/What_is_hard_link_and_soft_link_in_Linux
-[6]: https://www.wisdomjobs.com/e-university/network-administrator-interview-questions.html
-[7]: https://unix.stackexchange.com/questions/105/chroot-jail-what-is-it-and-how-do-i-use-it
-[8]: https://serverfault.com/questions/391370/how-to-prevent-zero-day-attacks
-[9]: https://unix.stackexchange.com/a/153586/8369
-[10]: https://blog.netwrix.com/2018/07/23/systems-administrator-salary-in-2018-how-much-can-you-earn/
diff --git a/sources/tech/20191007 Using the Java Persistence API.md b/sources/tech/20191007 Using the Java Persistence API.md
deleted file mode 100644
index 6b16213fc1..0000000000
--- a/sources/tech/20191007 Using the Java Persistence API.md
+++ /dev/null
@@ -1,273 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (runningwater)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Using the Java Persistence API)
-[#]: via: (https://opensource.com/article/19/10/using-java-persistence-api)
-[#]: author: (Stephon Brown https://opensource.com/users/stephb)
-
-Using the Java Persistence API
-======
-Learn how to use the JPA by building an example app for a bike store.
-![Coffee beans][1]
-
-The Java Persistence API (JPA) is an important Java functionality for application developers to understand. It translates exactly how Java developers turn method calls on objects into accessing, persisting, and managing data stored in NoSQL and relational databases.
-
-This article examines the JPA in detail through a tutorial example of building a bicycle loaning service. This example will create a create, read, update, and delete (CRUD) layer for a larger application using the Spring Boot framework, the MongoDB database (which is [no longer open source][2]), and the Maven package manager. I also use NetBeans 11 as my IDE of choice.
-
-This tutorial focuses on the open source angle of the Java Persistence API, rather than the tools, to show how it works. This is all about learning the pattern of programming applications, but it's still smart to understand the software. You can access the full code in my [GitHub repository][3].
-
-### Java: More than 'beans'
-
-Java is an object-oriented language that has gone through many changes since the Java Development Kit (JDK) was released in 1996. Understanding the language's various pathways and its virtual machine is a history lesson in itself; in brief, the language has forked in many directions, similar to the Linux kernel, since its release. There are standard editions that are free to the community, enterprise editions for business, and an open source alternatives contributed to by multiple vendors. Major versions are released at six-month intervals; since there are often major differences in features, you may want to do some research before choosing a version.
-
-All and all, Java is steeped in history. This tutorial focuses on [JDK 11][4], which is the open source implementation of Java 11, because it is one of the long-term-support versions that is still active.
-
- * **Spring Boot: **Spring Boot is a module from the larger Spring framework developed by Pivotal. Spring is a very popular framework for working with Java. It allows for a variety of architectures and configurations. Spring also offers support for web applications and security. Spring Boot offers basic configurations for bootstrapping various types of Java projects quickly. This tutorial uses Spring Boot to quickly write a console application and test functionality against the database.
- * **Maven:** Maven is a project/package manager developed by Apache. Maven allows for the management of packages and various dependencies within its POM.xml file. If you have used NPM, you may be familiar with how package managers function. Maven also manages build and reporting functionality.
- * **Lombok:** Lombok is a library that allows the creation of object getters/setters through annotation within the object file. This is already present in languages like C#, and Lombok introduces this functionality into Java.
- * **NetBeans: **NetBeans is a popular open source IDE that focuses specifically on Java development. Many of its tools provide an implementation for the latest Java SE and EE updates.
-
-
-
-This group of tools will be used to create a simple application for a fictional bike store. It will implement functionality for inserting collections for "Customer" and "Bike" objects.
-
-### Brewed to perfection
-
-Navigate to the [Spring Initializr][5]. This website enables you to generate basic project needs for Spring Boot and the dependencies you will need for the project. Select the following options:
-
- 1. **Project:** Maven Project
- 2. **Language:** Java
- 3. **Spring Boot:** 2.1.8 (or the most stable release)
- 4. **Project Metadata:** Whatever your naming conventions are (e.g., **com.stephb**)
- * You can keep Artifact as "Demo"
- 5. **Dependencies:** Add:
- * Spring Data MongoDB
- * Lombok
-
-
-
-Click **Download** and open the new project in your chosen IDE (e.g., NetBeans).
-
-#### Model outline
-
-The models represent information collected about specific objects in the program that will be persisted in your database. Focus on two objects: **Customer** and **Bike**. First, create a **dto** folder within the **src** folder. Then, create the two Java class objects named **Customer.java** and **Bike.java**. They will be structured in the program as follows:
-
-**Customer. Java**
-
-
-```
- 1 package com.stephb.JavaMongo.dto;
- 2
- 3 import lombok.Getter;
- 4 import lombok.Setter;
- 5 import org.springframework.data.annotation.Id;
- 6
- 7 /**
- 8 *
- 9 * @author stephon
-10 */
-11 @Getter @Setter
-12 public class Customer {
-13
-14 private @Id [String][6] id;
-15 private [String][6] emailAddress;
-16 private [String][6] firstName;
-17 private [String][6] lastName;
-18 private [String][6] address;
-19
-20 }
-```
-
-**Bike.java**
-
-
-```
- 1 package com.stephb.JavaMongo.dto;
- 2
- 3 import lombok.Getter;
- 4 import lombok.Setter;
- 5 import org.springframework.data.annotation.Id;
- 6
- 7 /**
- 8 *
- 9 * @author stephon
-10 */
-11 @Getter @Setter
-12 public class Bike {
-13 private @Id [String][6] id;
-14 private [String][6] modelNumber;
-15 private [String][6] color;
-16 private [String][6] description;
-17
-18 @Override
-19 public [String][6] toString() {
-20 return "This bike model is " + this.modelNumber + " is the color " + this.color + " and is " + description;
-21 }
-22 }
-```
-
-As you can see, Lombok annotation is used within the object to generate the getters/setters for the properties/attributes. Properties can specifically receive the annotations if you do not want all of the attributes to have getters/setters within that class. These two classes will form the container carrying your data to wherever you want to display information.
-
-#### Set up a database
-
-I used a [Mongo Docker][7] container for testing. If you have MongoDB installed on your system, you do not have to run an instance in Docker. You can install MongoDB from its website by selecting your system information and following the installation instructions.
-
-After installing, you can interact with your new MongoDB server through the command line, a GUI such as MongoDB Compass, or IDE drivers for connecting to data sources. Now you can define your data layer to pull, transform, and persist your data. To set your database access properties, navigate to the **applications.properties** file in your application and provide the following:
-
-
-```
- 1 spring.data.mongodb.host=localhost
- 2 spring.data.mongodb.port=27017
- 3 spring.data.mongodb.database=BikeStore
-```
-
-#### Define the data access object/data access layer
-
-The data access objects (DAO) in the data access layer (DAL) will define how you will interact with data in the database. The awesome thing about using a **spring-boot-starter** is that most of the work for querying the database is already done.
-
-Start with the **Customer** DAO. Create an interface in a new **dao** folder within the **src** folder, then create another Java class name called **CustomerRepository.java**. The class should look like:
-
-
-```
- 1 package com.stephb.JavaMongo.dao;
- 2
- 3 import com.stephb.JavaMongo.dto.Customer;
- 4 import java.util.List;
- 5 import org.springframework.data.mongodb.repository.MongoRepository;
- 6
- 7 /**
- 8 *
- 9 * @author stephon
-10 */
-11 public interface CustomerRepository extends MongoRepository<Customer, String>{
-12 @Override
-13 public List<Customer> findAll();
-14 public List<Customer> findByFirstName([String][6] firstName);
-15 public List<Customer> findByLastName([String][6] lastName);
-16 }
-```
-
-This class is an interface that extends or inherits from the **MongoRepository** class with your DTO (**Customer.java**) and a string because they will be used for querying with your custom functions. Because you have inherited from this class, you have access to many functions that allow persistence and querying of your object without having to implement or reference your own functions. For example, after you instantiate the **CustomerRepository** object, you can use the **Save** function immediately. You can also override these functions if you need more extended functionality. I created a few custom queries to search my collection, given specific elements of my object.
-
-The **Bike** object also has a repository for interacting with the database. Implement it very similarly to the **CustomerRepository**. It should look like:
-
-
-```
- 1 package com.stephb.JavaMongo.dao;
- 2
- 3 import com.stephb.JavaMongo.dto.Bike;
- 4 import java.util.List;
- 5 import org.springframework.data.mongodb.repository.MongoRepository;
- 6
- 7 /**
- 8 *
- 9 * @author stephon
-10 */
-11 public interface BikeRepository extends MongoRepository<Bike,String>{
-12 public Bike findByModelNumber([String][6] modelNumber);
-13 @Override
-14 public List<Bike> findAll();
-15 public List<Bike> findByColor([String][6] color);
-16 }
-```
-
-#### Run your program
-
-Now that you have a way to structure your data and a way to pull, transform, and persist it, run your program!
-
-Navigate to your **Application.java** file (it may have a different name, depending on what you named your application, but it should include "application"). Where the class is defined, include an **implements CommandLineRunner** afterward. This will allow you to implement a **run** method to create a command-line application. Override the **run** method provided by the **CommandLineRunner** interface and include the following to test the **BikeRepository**:
-
-
-```
- 1 package com.stephb.JavaMongo;
- 2
- 3 import com.stephb.JavaMongo.dao.BikeRepository;
- 4 import com.stephb.JavaMongo.dao.CustomerRepository;
- 5 import com.stephb.JavaMongo.dto.Bike;
- 6 import java.util.Scanner;
- 7 import org.springframework.beans.factory.annotation.Autowired;
- 8 import org.springframework.boot.CommandLineRunner;
- 9 import org.springframework.boot.SpringApplication;
-10 import org.springframework.boot.autoconfigure.SpringBootApplication;
-11
-12
-13 @SpringBootApplication
-14 public class JavaMongoApplication implements CommandLineRunner {
-15 @Autowired
-16 private BikeRepository bikeRepo;
-17 private CustomerRepository custRepo;
-18
-19 public static void main([String][6][] args) {
-20 SpringApplication.run(JavaMongoApplication.class, args);
-21 }
-22 @Override
-23 public void run([String][6]... args) throws [Exception][8] {
-24 Scanner scan = new Scanner([System][9].in);
-25 [String][6] response = "";
-26 boolean running = true;
-27 while(running){
-28 [System][9].out.println("What would you like to create? \n C: The Customer \n B: Bike? \n X:Close");
-29 response = scan.nextLine();
-30 if ("B".equals(response.toUpperCase())) {
-31 [String][6][] bikeInformation = new [String][6][3];
-32 [System][9].out.println("Enter the information for the Bike");
-33 [System][9].out.println("Model Number");
-34 bikeInformation[0] = scan.nextLine();
-35 [System][9].out.println("Color");
-36 bikeInformation[1] = scan.nextLine();
-37 [System][9].out.println("Description");
-38 bikeInformation[2] = scan.nextLine();
-39
-40 Bike bike = new Bike();
-41 bike.setModelNumber(bikeInformation[0]);
-42 bike.setColor(bikeInformation[1]);
-43 bike.setDescription(bikeInformation[2]);
-44
-45 bike = bikeRepo.save(bike);
-46 [System][9].out.println(bike.toString());
-47
-48
-49 } else if ("X".equals(response.toUpperCase())) {
-50 [System][9].out.println("Bye");
-51 running = false;
-52 } else {
-53 [System][9].out.println("Sorry nothing else works right now!");
-54 }
-55 }
-56
-57 }
-58 }
-```
-
-The **@Autowired** annotation allows automatic dependency injection of the **BikeRepository** and **CustomerRepository** beans. You will use these classes to persist and gather data from the database.
-
-There you have it! You have created a command-line application that connects to a database and is able to perform CRUD operations with minimal code on your part.
-
-### Conclusion
-
-Translating from programming language concepts like objects and classes into calls to store, retrieve, or change data in a database is essential to building an application. The Java Persistence API (JPA) is an important tool in the Java developer's toolkit to solve that challenge. What databases are you exploring in Java? Please share in the comments.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/using-java-persistence-api
-
-作者：[Stephon Brown][a]
-选题：[lujun9972][b]
-译者：[runningwater](https://github.com/runningwater)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/stephb
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/java-coffee-beans.jpg?itok=3hkjX5We (Coffee beans)
-[2]: https://www.techrepublic.com/article/mongodb-ceo-tells-hard-truths-about-commercial-open-source/
-[3]: https://github.com/StephonBrown/SpringMongoJava
-[4]: https://openjdk.java.net/projects/jdk/11/
-[5]: https://start.spring.io/
-[6]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+string
-[7]: https://hub.docker.com/_/mongo
-[8]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+exception
-[9]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+system
diff --git a/sources/tech/20191017 How to type emoji on Linux.md b/sources/tech/20191017 How to type emoji on Linux.md
deleted file mode 100644
index ff85c55938..0000000000
--- a/sources/tech/20191017 How to type emoji on Linux.md
+++ /dev/null
@@ -1,146 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to type emoji on Linux)
-[#]: via: (https://opensource.com/article/19/10/how-type-emoji-linux)
-[#]: author: (Seth Kenlon https://opensource.com/users/seth)
-
-How to type emoji on Linux
-======
-The GNOME desktop makes it easy to use emoji in your communications.
-![A cat under a keyboard.][1]
-
-Emoji are those fanciful pictograms that snuck into the Unicode character space. They're all the rage online, and people use them for all kinds of surprising things, from signifying reactions on social media to serving as visual labels for important file names. There are many ways to enter Unicode characters on Linux, but the GNOME desktop makes it easy to find and type an emoji.
-
-![Emoji in Emacs][2]
-
-### Requirements
-
-For this easy method, you must be running Linux with the [GNOME][3] desktop.
-
-You must also have an emoji font installed. There are many to choose from, so do a search for _emoji_ using your favorite software installer application or package manager.
-
-For example, on Fedora:
-
-
-```
-$ sudo dnf search emoji
-emoji-picker.noarch : An emoji selection tool
-unicode-emoji.noarch : Unicode Emoji Data Files
-eosrei-emojione-fonts.noarch : A color emoji font
-twitter-twemoji-fonts.noarch : Twitter Emoji for everyone
-google-android-emoji-fonts.noarch : Android Emoji font released by Google
-google-noto-emoji-fonts.noarch : Google “Noto Emoji” Black-and-White emoji font
-google-noto-emoji-color-fonts.noarch : Google “Noto Color Emoji” colored emoji font
-[...]
-```
-
-On Ubuntu or Debian, use **apt search** instead.
-
-I'm using [Google Noto Color Emoji][4] in this article.
-
-### Get set up
-
-To get set up, launch GNOME's Settings application.
-
- 1. In Settings, click the **Region & Language** category in the left column.
- 2. Click the plus symbol (**+**) under the **Input Sources** heading to bring up the **Add an Input Source** panel.
-
-
-
-![Add a new input source][5]
-
- 3. In the **Add an Input Source** panel, click the hamburger menu at the bottom of the input list.
-
-
-
-![Add an Input Source panel][6]
-
- 4. Scroll to the bottom of the list and select **Other**.
- 5. In the **Other** list, find **Other (Typing Booster)**. (You can type **boost** in the search field at the bottom to filter the list.)
-
-
-
-![Find Other \(Typing Booster\) in inputs][7]
-
- 6. Click the **Add** button in the top-right corner of the panel to add the input source to GNOME.
-
-
-
-Once you've done that, you can close the Settings window.
-
-#### Switch to Typing Booster
-
-You now have a new icon in the top-right of your GNOME desktop. By default, it's set to the two-letter abbreviation of your language (**en** for English, **eo** for Esperanto, **es** for Español, and so on). If you press the **Super** key (the key with a Linux penguin, Windows logo, or Mac Command symbol) and the **Spacebar** together on your keyboard, you will switch input sources from your default source to the next on your input list. In this example, you only have two input sources: your default language and Typing Booster.
-
-Try pressing **Super**+**Spacebar** together and watch the input name and icon change.
-
-#### Configure Typing Booster
-
-With the Typing Booster input method active, click the input sources icon in the top-right of your screen, select **Unicode symbols and emoji predictions**, and set it to **On**.
-
-![Set Unicode symbols and emoji predictions to On][8]
-
-This makes Typing Booster dedicated to typing emoji, which isn't all Typing Booster is good for, but in the context of this article it's exactly what is needed.
-
-### Type emoji
-
-With Typing Booster still active, open a text editor like Gedit, a web browser, or anything that you know understands Unicode characters, and type "_thumbs up_." As you type, Typing Booster searches for matching emoji names.
-
-![Typing Booster searching for emojis][9]
-
-To leave emoji mode, press **Super**+**Spacebar** again, and your input source goes back to your default language.
-
-### Switch the switcher
-
-If the **Super**+**Spacebar** keyboard shortcut is not natural for you, then you can change it to a different combination. In GNOME Settings, navigate to **Devices** and select **Keyboard**.
-
-In the top bar of the **Keyboard** window, search for **Input** to filter the list. Set **Switch to next input source** to a key combination of your choice.
-
-![Changing keystroke combination in GNOME settings][10]
-
-### Unicode input
-
-The fact is, keyboards were designed for a 26-letter (or thereabouts) alphabet along with as many numerals and symbols. ASCII has more characters than what you find on a typical keyboard, to say nothing of the millions of characters within Unicode. If you want to type Unicode characters into a modern Linux application but don't want to switch to Typing Booster, then you can use the Unicode input shortcut.
-
- 1. With your default language active, open a text editor like Gedit, a web browser, or any application you know accepts Unicode.
- 2. Press **Ctrl**+**Shift**+**U** on your keyboard to enter Unicode entry mode. Release the keys.
- 3. You are currently in Unicode entry mode, so type a number of a Unicode symbol. For instance, try **1F44D** for a 👍 symbol, or **2620** for a ☠ symbol. To get the number code of a Unicode symbol, you can search the internet or refer to the [Unicode specification][11].
-
-
-
-### Pragmatic emoji-ism
-
-Emoji are fun and expressive. They can make your text unique to you. They can also be utilitarian. Because emoji are Unicode characters, they can be used anywhere a font can be used, and they can be used the same way any alphabetic character can be used. For instance, if you want to mark a series of files with a special symbol, you can add an emoji to the name, and you can filter by that emoji in Search.
-
-![Labeling a file with emoji][12]
-
-Use emoji all you want because Linux is a Unicode-friendly environment, and it's getting friendlier with every release.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/how-type-emoji-linux
-
-作者：[Seth Kenlon][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/seth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc-lead_cat-keyboard.png?itok=fuNmiGV- (A cat under a keyboard.)
-[2]: https://opensource.com/sites/default/files/uploads/emacs-emoji.jpg (Emoji in Emacs)
-[3]: https://www.gnome.org/
-[4]: https://www.google.com/get/noto/help/emoji/
-[5]: https://opensource.com/sites/default/files/uploads/gnome-setting-region-add.png (Add a new input source)
-[6]: https://opensource.com/sites/default/files/uploads/gnome-setting-input-list.png (Add an Input Source panel)
-[7]: https://opensource.com/sites/default/files/uploads/gnome-setting-input-other-typing-booster.png (Find Other (Typing Booster) in inputs)
-[8]: https://opensource.com/sites/default/files/uploads/emoji-input-on.jpg (Set Unicode symbols and emoji predictions to On)
-[9]: https://opensource.com/sites/default/files/uploads/emoji-input.jpg (Typing Booster searching for emojis)
-[10]: https://opensource.com/sites/default/files/uploads/gnome-setting-keyboard-switch-input.jpg (Changing keystroke combination in GNOME settings)
-[11]: http://unicode.org/emoji/charts/full-emoji-list.html
-[12]: https://opensource.com/sites/default/files/uploads/file-label.png (Labeling a file with emoji)
diff --git a/sources/tech/20191020 14 SCP Command Examples to Securely Transfer Files in Linux.md b/sources/tech/20191020 14 SCP Command Examples to Securely Transfer Files in Linux.md
deleted file mode 100644
index e34b1d825c..0000000000
--- a/sources/tech/20191020 14 SCP Command Examples to Securely Transfer Files in Linux.md
+++ /dev/null
@@ -1,241 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (14 SCP Command Examples to Securely Transfer Files in Linux)
-[#]: via: (https://www.linuxtechi.com/scp-command-examples-in-linux/)
-[#]: author: (Pradeep Kumar https://www.linuxtechi.com/author/pradeep/)
-
-14 SCP Command Examples to Securely Transfer Files in Linux
-======
-
-**SCP** (Secure Copy) is command line tool in Linux and Unix like systems which is used to transfer files and directories across the systems securely over the network. When we use scp command to copy files and directories from our local system to remote system then in the backend it makes **ssh connection** to remote system. In other words, we can say scp uses the same **SSH security mechanism** in the backend, it needs either password or keys for authentication.
-
-[![scp-command-examples-linux][1]][2]
-
-In this tutorial we will discuss 14 useful Linux scp command examples.
-
-**Syntax of scp command:**
-
-### scp <options> <files_or_directories> [root@linuxtechi][3]_host:/<folder>
-
-### scp <options> [root@linuxtechi][3]_host:/files <folder_local_system>
-
-First syntax of scp command demonstrate how to copy files or directories from local system to target host under the specific folder.
-
-Second syntax of scp command demonstrate how files from target host is copied into local system.
-
-Some of the most widely used options in scp command are listed below,
-
- * -C Enable Compression
- * -i identity File or private key
- * -l limit the bandwidth while copying
- * -P ssh port number of target host
- * -p Preserves permissions, modes and access time of files while copying
- * -q Suppress warning message of SSH
- * -r Copy files and directories recursively
- * -v verbose output
-
-
-
-Let’s jump into the examples now!!!!
-
-###### Example:1) Copy a file from local system to remote system using scp
-
-Let’s assume we want to copy jdk rpm package from our local Linux system to remote system (172.20.10.8) using scp command, use the following command,
-
-```
-[root@linuxtechi ~]$ scp jdk-linux-x64_bin.rpm root@linuxtechi:/opt
-root@linuxtechi's password:
-jdk-linux-x64_bin.rpm 100% 10MB 27.1MB/s 00:00
-[root@linuxtechi ~]$
-```
-
-Above command will copy jdk rpm package file to remote system under /opt folder.
-
-###### Example:2) Copy a file from remote System to local system using scp
-
-Let’s suppose we want to copy a file from remote system to our local system under the /tmp folder, execute the following scp command,
-
-```
-[root@linuxtechi ~]$ scp root@linuxtechi:/root/Technical-Doc-RHS.odt /tmp
-root@linuxtechi's password:
-Technical-Doc-RHS.odt 100% 1109KB 31.8MB/s 00:00
-[root@linuxtechi ~]$ ls -l /tmp/Technical-Doc-RHS.odt
--rwx------. 1 pkumar pkumar 1135521 Oct 19 11:12 /tmp/Technical-Doc-RHS.odt
-[root@linuxtechi ~]$
-```
-
-###### Example:3) Verbose Output while transferring files using scp (-v)
-
-In scp command, we can enable the verbose output using -v option, using verbose output we can easily find what exactly is happening in the background. This becomes very useful in **debugging connection**, **authentication** and **configuration problems**.
-
-```
-root@linuxtechi ~]$ scp -v jdk-linux-x64_bin.rpm root@linuxtechi:/opt
-Executing: program /usr/bin/ssh host 172.20.10.8, user root, command scp -v -t /opt
-OpenSSH_7.8p1, OpenSSL 1.1.1 FIPS 11 Sep 2018
-debug1: Reading configuration data /etc/ssh/ssh_config
-debug1: Reading configuration data /etc/ssh/ssh_config.d/05-redhat.conf
-debug1: Reading configuration data /etc/crypto-policies/back-ends/openssh.config
-debug1: /etc/ssh/ssh_config.d/05-redhat.conf line 8: Applying options for *
-debug1: Connecting to 172.20.10.8 [172.20.10.8] port 22.
-debug1: Connection established.
-…………
-debug1: Next authentication method: password
-root@linuxtechi's password:
-```
-
-###### Example:4) Transfer multiple files to remote system
-
-Multiple files can be copied / transferred to remote system using scp command in one go, in scp command specify the multiple files separated by space, example is shown below
-
-```
-[root@linuxtechi ~]$ scp install.txt index.html jdk-linux-x64_bin.rpm root@linuxtechi:/mnt
-root@linuxtechi's password:
-install.txt 100% 0 0.0KB/s 00:00
-index.html 100% 85KB 7.2MB/s 00:00
-jdk-linux-x64_bin.rpm 100% 10MB 25.3MB/s 00:00
-[root@linuxtechi ~]$
-```
-
-###### Example:5) Transfer files across two remote hosts
-
-Using scp command we can copy files and directories between two remote hosts, let’s suppose we have a local Linux system which can connect to two remote Linux systems, so from my local linux system I can use scp command to copy files across these two systems,
-
-Syntax:
-
-### scp [root@linuxtechi][3]_hosts1:/<files_to_transfer> [root@linuxtechi][3]_host2:/<folder>
-
-Example is shown below,
-
-```
-# scp root@linuxtechi:~/backup-Oct.zip root@linuxtechi:/tmp
-# ssh root@linuxtechi "ls -l /tmp/backup-Oct.zip"
--rwx------. 1 root root 747438080 Oct 19 12:02 /tmp/backup-Oct.zip
-```
-
-###### Example:6) Copy files and directories recursively (-r)
-
-Use -r option in scp command to recursively copy the entire directory from one system to another, example is shown below,
-
-```
-[root@linuxtechi ~]$ scp -r Downloads root@linuxtechi:/opt
-```
-
-Use below command to verify whether Download folder is copied to remote system or not,
-
-```
-[root@linuxtechi ~]$ ssh root@linuxtechi "ls -ld /opt/Downloads"
-drwxr-xr-x. 2 root root 75 Oct 19 12:10 /opt/Downloads
-[root@linuxtechi ~]$
-```
-
-###### Example:7) Increase transfer speed by enabling compression (-C)
-
-In scp command, we can increase the transfer speed by enabling the compression using -C option, it will automatically enable compression at source and decompression at destination host.
-
-```
-root@linuxtechi ~]$ scp -r -C Downloads root@linuxtechi:/mnt
-```
-
-In the above example we are transferring the Download directory with compression enabled.
-
-###### Example:8) Limit bandwidth while copying ( -l )
-
-Use ‘-l’ option in scp command to put limit on bandwidth usage while copying. Bandwidth is specified in Kbit/s, example is shown below,
-
-```
-[root@linuxtechi ~]$ scp -l 500 jdk-linux-x64_bin.rpm root@linuxtechi:/var
-```
-
-###### Example:9) Specify different ssh port while scp ( -P)
-
-There can be some scenario where ssh port is changed on destination host, so while using scp command we can specify the ssh port number using ‘-P’ option.
-
-```
-[root@linuxtechi ~]$ scp -P 2022 jdk-linux-x64_bin.rpm root@linuxtechi:/var
-```
-
-In above example, ssh port for remote host is “2022”
-
-###### Example:10) Preserves permissions, modes and access time of files while copying (-p)
-
-Use “-p” option in scp command to preserve permissions, access time and modes while copying from source to destination
-
-```
-[root@linuxtechi ~]$ scp -p jdk-linux-x64_bin.rpm root@linuxtechi:/var/tmp
-jdk-linux-x64_bin.rpm 100% 10MB 13.5MB/s 00:00
-[root@linuxtechi ~]$
-```
-
-###### Example:11) Transferring files in quiet mode ( -q) in scp
-
-Use ‘-q’ option in scp command to suppress transfer progress, warning and diagnostic messages of ssh. Example is shown below,
-
-```
-[root@linuxtechi ~]$ scp -q -r Downloads root@linuxtechi:/var/tmp
-[root@linuxtechi ~]$
-```
-
-###### Example:12) Use Identify file in scp while transferring ( -i )
-
-In most of the Linux environments, keys-based authentication is preferred. In scp command we specify the identify file or private key file using ‘-i’ option, example is shown below,
-
-```
-[root@linuxtechi ~]$ scp -i my_key.pem -r Downloads root@linuxtechi:/root
-```
-
-In above example, “my_key.pem” is the identity file or private key file.
-
-###### Example:13) Use different ‘ssh_config’ file in scp ( -F)
-
-There are some scenarios where you use different networks to connect to Linux systems, may be some network is behind proxy servers, so in that case we must have different **ssh_config** file.
-
-Different ssh_config file in scp command is specified via ‘-F’ option, example is shown below
-
-```
-[root@linuxtechi ~]$ scp -F /home/pkumar/new_ssh_config -r Downloads root@linuxtechi:/root
-root@linuxtechi's password:
-jdk-linux-x64_bin.rpm 100% 10MB 16.6MB/s 00:00
-backup-Oct.zip 100% 713MB 41.9MB/s 00:17
-index.html 100% 85KB 6.6MB/s 00:00
-[root@linuxtechi ~]$
-```
-
-###### Example:14) Use Different Cipher in scp command (-c)
-
-By default, scp uses ‘AES-128’ cipher to encrypt the files. If you want to use another cipher in scp command then use ‘-c’ option followed by cipher name,
-
-Let’s suppose we want to use ‘3des-cbc’ cipher in scp command while transferring the files, run the following scp command
-
-```
-[root@linuxtechi ~]# scp -c 3des-cbc -r Downloads root@linuxtechi:/root
-```
-
-Use the below command to list ssh and scp ciphers,
-
-```
-[root@linuxtechi ~]# ssh -Q cipher localhost | paste -d , -s -
-3des-cbc,aes128-cbc,aes192-cbc,aes256-cbc,root@linuxtechi,aes128-ctr,aes192-ctr,aes256-ctr,root@linuxtechi,root@linuxtechi,root@linuxtechi
-[root@linuxtechi ~]#
-```
-
-That’s all from this tutorial, to get more details about scp command, kindly refer its man page. Please do share your feedback and comments in comments section below.
-
---------------------------------------------------------------------------------
-
-via: https://www.linuxtechi.com/scp-command-examples-in-linux/
-
-作者：[Pradeep Kumar][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://www.linuxtechi.com/author/pradeep/
-[b]: https://github.com/lujun9972
-[1]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
-[2]: https://www.linuxtechi.com/wp-content/uploads/2019/10/scp-command-examples-linux.jpg
-[3]: https://www.linuxtechi.com/cdn-cgi/l/email-protection
diff --git a/sources/tech/20191022 How to program with Bash- Logical operators and shell expansions.md b/sources/tech/20191022 How to program with Bash- Logical operators and shell expansions.md
deleted file mode 100644
index 024af38122..0000000000
--- a/sources/tech/20191022 How to program with Bash- Logical operators and shell expansions.md
+++ /dev/null
@@ -1,498 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to program with Bash: Logical operators and shell expansions)
-[#]: via: (https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions)
-[#]: author: (David Both https://opensource.com/users/dboth)
-
-How to program with Bash: Logical operators and shell expansions
-======
-Learn about logical operators and shell expansions, in the second
-article in this three-part series on programming with Bash.
-![Women in computing and open source v5][1]
-
-Bash is a powerful programming language, one perfectly designed for use on the command line and in shell scripts. This three-part series (which is based on my [three-volume Linux self-study course][2]) explores using Bash as a programming language on the command-line interface (CLI).
-
-The [first article][3] explored some simple command-line programming with Bash, including using variables and control operators. This second article looks into the types of file, string, numeric, and miscellaneous logical operators that provide execution-flow control logic and different types of shell expansions in Bash. The third and final article in the series will explore the **for**, **while**, and **until** loops that enable repetitive operations.
-
-Logical operators are the basis for making decisions in a program and executing different sets of instructions based on those decisions. This is sometimes called flow control.
-
-### Logical operators
-
-Bash has a large set of logical operators that can be used in conditional expressions. The most basic form of the **if** control structure tests for a condition and then executes a list of program statements if the condition is true. There are three types of operators: file, numeric, and non-numeric operators. Each operator returns true (0) if the condition is met and false (1) if the condition is not met.
-
-The functional syntax of these comparison operators is one or two arguments with an operator that are placed within square braces, followed by a list of program statements that are executed if the condition is true, and an optional list of program statements if the condition is false:
-
-
-```
-if [ arg1 operator arg2 ] ; then list
-or
-if [ arg1 operator arg2 ] ; then list ; else list ; fi
-```
-
-The spaces in the comparison are required as shown. The single square braces, **[** and **]**, are the traditional Bash symbols that are equivalent to the **test** command:
-
-
-```
-`if test arg1 operator arg2 ; then list`
-```
-
-There is also a more recent syntax that offers a few advantages and that some sysadmins prefer. This format is a bit less compatible with different versions of Bash and other shells, such as ksh (the Korn shell). It looks like:
-
-
-```
-`if [[ arg1 operator arg2 ]] ; then list`
-```
-
-#### File operators
-
-File operators are a powerful set of logical operators within Bash. Figure 1 lists more than 20 different operators that Bash can perform on files. I use them quite frequently in my scripts.
-
-Operator | Description
----|---
--a filename | True if the file exists; it can be empty or have some content but, so long as it exists, this will be true
--b filename | True if the file exists and is a block special file such as a hard drive like **/dev/sda** or **/dev/sda1**
--c filename | True if the file exists and is a character special file such as a TTY device like **/dev/TTY1**
--d filename | True if the file exists and is a directory
--e filename | True if the file exists; this is the same as **-a** above
--f filename | True if the file exists and is a regular file, as opposed to a directory, a device special file, or a link, among others
--g filename | True if the file exists and is **set-group-id**, **SETGID**
--h filename | True if the file exists and is a symbolic link
--k filename | True if the file exists and its "sticky'" bit is set
--p filename | True if the file exists and is a named pipe (FIFO)
--r filename | True if the file exists and is readable, i.e., has its read bit set
--s filename | True if the file exists and has a size greater than zero; a file that exists but that has a size of zero will return false
--t fd | True if the file descriptor **fd** is open and refers to a terminal
--u filename | True if the file exists and its **set-user-id** bit is set
--w filename | True if the file exists and is writable
--x filename | True if the file exists and is executable
--G filename | True if the file exists and is owned by the effective group ID
--L filename | True if the file exists and is a symbolic link
--N filename | True if the file exists and has been modified since it was last read
--O filename | True if the file exists and is owned by the effective user ID
--S filename | True if the file exists and is a socket
-file1 -ef file2 | True if file1 and file2 refer to the same device and iNode numbers
-file1 -nt file2 | True if file1 is newer (according to modification date) than file2, or if file1 exists and file2 does not
-file1 -ot file2 | True if file1 is older than file2, or if file2 exists and file1 does not
-
-_**Fig. 1: The Bash file operators**_
-
-As an example, start by testing for the existence of a file:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; if [ -e $File ] ; then echo "The file $File exists." ; else echo "The file $File does not exist." ; fi
-The file TestFile1 does not exist.
-[student@studentvm1 testdir]$
-```
-
-Next, create a file for testing named **TestFile1**. For now, it does not need to contain any data:
-
-
-```
-`[student@studentvm1 testdir]$ touch TestFile1`
-```
-
-It is easy to change the value of the **$File** variable rather than a text string for the file name in multiple locations in this short CLI program:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; if [ -e $File ] ; then echo "The file $File exists." ; else echo "The file $File does not exist." ; fi
-The file TestFile1 exists.
-[student@studentvm1 testdir]$
-```
-
-Now, run a test to determine whether a file exists and has a non-zero length, which means it contains data. You want to test for three conditions: 1. the file does not exist; 2. the file exists and is empty; and 3. the file exists and contains data. Therefore, you need a more complex set of tests—use the **elif** stanza in the **if-elif-else** construct to test for all of the conditions:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; if [ -s $File ] ; then echo "$File exists and contains data." ; fi
-[student@studentvm1 testdir]$
-```
-
-In this case, the file exists but does not contain any data. Add some data and try again:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; echo "This is file $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; fi
-TestFile1 exists and contains data.
-[student@studentvm1 testdir]$
-```
-
-That works, but it is only truly accurate for one specific condition out of the three possible ones. Add an **else** stanza so you can be somewhat more accurate, and delete the file so you can fully test this new code:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; rm $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi
-TestFile1 does not exist or is empty.
-```
-
-Now create an empty file to test:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi
-TestFile1 does not exist or is empty.
-```
-
-Add some content to the file and test again:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; echo "This is file $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi
-TestFile1 exists and contains data.
-```
-
-Now, add the **elif** stanza to discriminate between a file that does not exist and one that is empty:
-
-
-```
-[student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; elif [ -e $File ] ; then echo "$File exists and is empty." ; else echo "$File does not exist." ; fi
-TestFile1 exists and is empty.
-[student@studentvm1 testdir]$ File="TestFile1" ; echo "This is $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; elif [ -e $File ] ; then echo "$File exists and is empty." ; else echo "$File does not exist." ; fi
-TestFile1 exists and contains data.
-[student@studentvm1 testdir]$
-```
-
-Now you have a Bash CLI program that can test for these three different conditions… but the possibilities are endless.
-
-It is easier to see the logic structure of the more complex compound commands if you arrange the program statements more like you would in a script that you can save in a file. Figure 2 shows how this would look. The indents of the program statements in each stanza of the **if-elif-else** structure help to clarify the logic.
-
-
-```
-File="TestFile1"
-echo "This is $File" > $File
-if [ -s $File ]
- then
- echo "$File exists and contains data."
-elif [ -e $File ]
- then
- echo "$File exists and is empty."
-else
- echo "$File does not exist."
-fi
-```
-
-_**Fig. 2: The command line program rewritten as it would appear in a script**_
-
-Logic this complex is too lengthy for most CLI programs. Although any Linux or Bash built-in commands may be used in CLI programs, as the CLI programs get longer and more complex, it makes more sense to create a script that is stored in a file and can be executed at any time, now or in the future.
-
-#### String comparison operators
-
-String comparison operators enable the comparison of alphanumeric strings of characters. There are only a few of these operators, which are listed in Figure 3.
-
-Operator | Description
----|---
--z string | True if the length of string is zero
--n string | True if the length of string is non-zero
-string1 == string2
-or
-string1 = string2 | True if the strings are equal; a single **=** should be used with the test command for POSIX conformance. When used with the **[[** command, this performs pattern matching as described above (compound commands).
-string1 != string2 | True if the strings are not equal
-string1 < string2 | True if string1 sorts before string2 lexicographically (refers to locale-specific sorting sequences for all alphanumeric and special characters)
-string1 > string2 | True if string1 sorts after string2 lexicographically
-
-_**Fig. 3: Bash string logical operators**_
-
-First, look at string length. The quotes around **$MyVar** in the comparison must be there for the comparison to work. (You should still be working in **~/testdir**.)
-
-
-```
-[student@studentvm1 testdir]$ MyVar="" ; if [ -z "" ] ; then echo "MyVar is zero length." ; else echo "MyVar contains data" ; fi
-MyVar is zero length.
-[student@studentvm1 testdir]$ MyVar="Random text" ; if [ -z "" ] ; then echo "MyVar is zero length." ; else echo "MyVar contains data" ; fi
-MyVar is zero length.
-```
-
-You could also do it this way:
-
-
-```
-[student@studentvm1 testdir]$ MyVar="Random text" ; if [ -n "$MyVar" ] ; then echo "MyVar contains data." ; else echo "MyVar is zero length" ; fi
-MyVar contains data.
-[student@studentvm1 testdir]$ MyVar="" ; if [ -n "$MyVar" ] ; then echo "MyVar contains data." ; else echo "MyVar is zero length" ; fi
-MyVar is zero length
-```
-
-Sometimes you may need to know a string's exact length. This is not a comparison, but it is related. Unfortunately, there is no simple way to determine the length of a string. There are a couple of ways to do it, but I think using the **expr** (evaluate expression) command is easiest. Read the man page for **expr** for more about what it can do. Note that quotes are required around the string or variable you're testing.
-
-
-```
-[student@studentvm1 testdir]$ MyVar="" ; expr length "$MyVar"
-0
-[student@studentvm1 testdir]$ MyVar="How long is this?" ; expr length "$MyVar"
-17
-[student@studentvm1 testdir]$ expr length "We can also find the length of a literal string as well as a variable."
-70
-```
-
-Regarding comparison operators, I use a lot of testing in my scripts to determine whether two strings are equal (i.e., identical). I use the non-POSIX version of this comparison operator:
-
-
-```
-[student@studentvm1 testdir]$ Var1="Hello World" ; Var2="Hello World" ; if [ "$Var1" == "$Var2" ] ; then echo "Var1 matches Var2" ; else echo "Var1 and Var2 do not match." ; fi
-Var1 matches Var2
-[student@studentvm1 testdir]$ Var1="Hello World" ; Var2="Hello world" ; if [ "$Var1" == "$Var2" ] ; then echo "Var1 matches Var2" ; else echo "Var1 and Var2 do not match." ; fi
-Var1 and Var2 do not match.
-```
-
-Experiment some more on your own to try out these operators.
-
-#### Numeric comparison operators
-
-Numeric operators make comparisons between two numeric arguments. Like the other operator classes, most are easy to understand.
-
-Operator | Description
----|---
-arg1 -eq arg2 | True if arg1 equals arg2
-arg1 -ne arg2 | True if arg1 is not equal to arg2
-arg1 -lt arg2 | True if arg1 is less than arg2
-arg1 -le arg2 | True if arg1 is less than or equal to arg2
-arg1 -gt arg2 | True if arg1 is greater than arg2
-arg1 -ge arg2 | True if arg1 is greater than or equal to arg2
-
-_**Fig. 4: Bash numeric comparison logical operators**_
-
-Here are some simple examples. The first instance sets the variable **$X** to 1, then tests to see if **$X** is equal to 1. In the second instance, **X** is set to 0, so the comparison is not true.
-
-
-```
-[student@studentvm1 testdir]$ X=1 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi
-X equals 1
-[student@studentvm1 testdir]$ X=0 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi
-X does not equal 1
-[student@studentvm1 testdir]$
-```
-
-Try some more experiments on your own.
-
-#### Miscellaneous operators
-
-These miscellaneous operators show whether a shell option is set or a shell variable has a value, but it does not discover the value of the variable, just whether it has one.
-
-Operator | Description
----|---
--o optname | True if the shell option optname is enabled (see the list of options under the description of the **-o** option to the Bash set builtin in the Bash man page)
--v varname | True if the shell variable varname is set (has been assigned a value)
--R varname | True if the shell variable varname is set and is a name reference
-
-_**Fig. 5: Miscellaneous Bash logical operators**_
-
-Experiment on your own to try out these operators.
-
-### Expansions
-
-Bash supports a number of types of expansions and substitutions that can be quite useful. According to the Bash man page, Bash has seven forms of expansions. This article looks at five of them: tilde expansion, arithmetic expansion, pathname expansion, brace expansion, and command substitution.
-
-#### Brace expansion
-
-Brace expansion is a method for generating arbitrary strings. (This tool is used below to create a large number of files for experiments with special pattern characters.) Brace expansion can be used to generate lists of arbitrary strings and insert them into a specific location within an enclosing static string or at either end of a static string. This may be hard to visualize, so it's best to just do it.
-
-First, here's what a brace expansion does:
-
-
-```
-[student@studentvm1 testdir]$ echo {string1,string2,string3}
-string1 string2 string3
-```
-
-Well, that is not very helpful, is it? But look what happens when you use it just a bit differently:
-
-
-```
-[student@studentvm1 testdir]$ echo "Hello "{David,Jen,Rikki,Jason}.
-Hello David. Hello Jen. Hello Rikki. Hello Jason.
-```
-
-That looks like something useful—it could save a good deal of typing. Now try this:
-
-
-```
-[student@studentvm1 testdir]$ echo b{ed,olt,ar}s
-beds bolts bars
-```
-
-I could go on, but you get the idea.
-
-#### Tilde expansion
-
-Arguably, the most common expansion is the tilde (**~**) expansion. When you use this in a command like **cd ~/Documents**, the Bash shell expands it as a shortcut to the user's full home directory.
-
-Use these Bash programs to observe the effects of the tilde expansion:
-
-
-```
-[student@studentvm1 testdir]$ echo ~
-/home/student
-[student@studentvm1 testdir]$ echo ~/Documents
-/home/student/Documents
-[student@studentvm1 testdir]$ Var1=~/Documents ; echo $Var1 ; cd $Var1
-/home/student/Documents
-[student@studentvm1 Documents]$
-```
-
-#### Pathname expansion
-
-Pathname expansion is a fancy term expanding file-globbing patterns, using the characters **?** and *****, into the full names of directories that match the pattern. File globbing refers to special pattern characters that enable significant flexibility in matching file names, directories, and other strings when performing various actions. These special pattern characters allow matching single, multiple, or specific characters in a string.
-
- * **?** — Matches only one of any character in the specified location within the string
- * ***** — Matches zero or more of any character in the specified location within the string
-
-
-
-This expansion is applied to matching directory names. To see how this works, ensure that **testdir** is the present working directory (PWD) and start with a plain listing (the contents of my home directory will be different from yours):
-
-
-```
-[student@studentvm1 testdir]$ ls
-chapter6 cpuHog.dos dmesg1.txt Documents Music softlink1 testdir6 Videos
-chapter7 cpuHog.Linux dmesg2.txt Downloads Pictures Templates testdir
-testdir cpuHog.mac dmesg3.txt file005 Public testdir tmp
-cpuHog Desktop dmesg.txt link3 random.txt testdir1 umask.test
-[student@studentvm1 testdir]$
-```
-
-Now list the directories that start with **Do**, **testdir/Documents**, and **testdir/Downloads**:
-
-
-```
-Documents:
-Directory01 file07 file15 test02 test10 test20 testfile13 TextFiles
-Directory02 file08 file16 test03 test11 testfile01 testfile14
-file01 file09 file17 test04 test12 testfile04 testfile15
-file02 file10 file18 test05 test13 testfile05 testfile16
-file03 file11 file19 test06 test14 testfile09 testfile17
-file04 file12 file20 test07 test15 testfile10 testfile18
-file05 file13 Student1.txt test08 test16 testfile11 testfile19
-file06 file14 test01 test09 test18 testfile12 testfile20
-
-Downloads:
-[student@studentvm1 testdir]$
-```
-
-Well, that did not do what you wanted. It listed the contents of the directories that begin with **Do**. To list only the directories and not their contents, use the **-d** option.
-
-
-```
-[student@studentvm1 testdir]$ ls -d Do*
-Documents Downloads
-[student@studentvm1 testdir]$
-```
-
-In both cases, the Bash shell expands the **Do*** pattern into the names of the two directories that match the pattern. But what if there are also files that match the pattern?
-
-
-```
-[student@studentvm1 testdir]$ touch Downtown ; ls -d Do*
-Documents Downloads Downtown
-[student@studentvm1 testdir]$
-```
-
-This shows the file, too. So any files that match the pattern are also expanded to their full names.
-
-#### Command substitution
-
-Command substitution is a form of expansion that allows the STDOUT data stream of one command to be used as the argument of another command; for example, as a list of items to be processed in a loop. The Bash man page says: "Command substitution allows the output of a command to replace the command name." I find that to be accurate if a bit obtuse.
-
-There are two forms of this substitution, **`command`** and **$(command)**. In the older form using back tics (**`**), using a backslash (**\**) in the command retains its literal meaning. However, when it's used in the newer parenthetical form, the backslash takes on its meaning as a special character. Note also that the parenthetical form uses only single parentheses to open and close the command statement.
-
-I frequently use this capability in command-line programs and scripts where the results of one command can be used as an argument for another command.
-
-Start with a very simple example that uses both forms of this expansion (again, ensure that **testdir** is the PWD):
-
-
-```
-[student@studentvm1 testdir]$ echo "Todays date is `date`"
-Todays date is Sun Apr 7 14:42:46 EDT 2019
-[student@studentvm1 testdir]$ echo "Todays date is $(date)"
-Todays date is Sun Apr 7 14:42:59 EDT 2019
-[student@studentvm1 testdir]$
-```
-
-The **-w** option to the **seq** utility adds leading zeros to the numbers generated so that they are all the same width, i.e., the same number of digits regardless of the value. This makes it easier to sort them in numeric sequence.
-
-The **seq** utility is used to generate a sequence of numbers:
-
-
-```
-[student@studentvm1 testdir]$ seq 5
-1
-2
-3
-4
-5
-[student@studentvm1 testdir]$ echo `seq 5`
-1 2 3 4 5
-[student@studentvm1 testdir]$
-```
-
-Now you can do something a bit more useful, like creating a large number of empty files for testing:
-
-
-```
-`[student@studentvm1 testdir]$ for I in $(seq -w 5000) ; do touch file-$I ; done`
-```
-
-In this usage, the statement **seq -w 5000** generates a list of numbers from one to 5,000. By using command substitution as part of the **for** statement, the list of numbers is used by the **for** statement to generate the numerical part of the file names.
-
-#### Arithmetic expansion
-
-Bash can perform integer math, but it is rather cumbersome (as you will soon see). The syntax for arithmetic expansion is **$((arithmetic-expression))**, using double parentheses to open and close the expression.
-
-Arithmetic expansion works like command substitution in a shell program or script; the value calculated from the expression replaces the expression for further evaluation by the shell.
-
-Once again, start with something simple:
-
-
-```
-[student@studentvm1 testdir]$ echo $((1+1))
-2
-[student@studentvm1 testdir]$ Var1=5 ; Var2=7 ; Var3=$((Var1*Var2)) ; echo "Var 3 = $Var3"
-Var 3 = 35
-```
-
-The following division results in zero because the result would be a decimal value of less than one:
-
-
-```
-[student@studentvm1 testdir]$ Var1=5 ; Var2=7 ; Var3=$((Var1/Var2)) ; echo "Var 3 = $Var3"
-Var 3 = 0
-```
-
-Here is a simple calculation I often do in a script or CLI program that tells me how much total virtual memory I have in a Linux host. The **free** command does not provide that data:
-
-
-```
-[student@studentvm1 testdir]$ RAM=`free | grep ^Mem | awk '{print $2}'` ; Swap=`free | grep ^Swap | awk '{print $2}'` ; echo "RAM = $RAM and Swap = $Swap" ; echo "Total Virtual memory is $((RAM+Swap))" ;
-RAM = 4037080 and Swap = 6291452
-Total Virtual memory is 10328532
-```
-
-I used the **`** character to delimit the sections of code used for command substitution.
-
-I use Bash arithmetic expansion mostly for checking system resource amounts in a script and then choose a program execution path based on the result.
-
-### Summary
-
-This article, the second in this series on Bash as a programming language, explored the Bash file, string, numeric, and miscellaneous logical operators that provide execution-flow control logic and the different types of shell expansions.
-
-The third article in this series will explore the use of loops for performing various types of iterative operations.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
-
-作者：[David Both][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/dboth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_women_computing_5.png?itok=YHpNs_ss (Women in computing and open source v5)
-[2]: http://www.both.org/?page_id=1183
-[3]: https://opensource.com/article/19/10/programming-bash-part-1
diff --git a/sources/tech/20191023 How to program with Bash- Loops.md b/sources/tech/20191023 How to program with Bash- Loops.md
deleted file mode 100644
index e582bda447..0000000000
--- a/sources/tech/20191023 How to program with Bash- Loops.md
+++ /dev/null
@@ -1,352 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to program with Bash: Loops)
-[#]: via: (https://opensource.com/article/19/10/programming-bash-loops)
-[#]: author: (David Both https://opensource.com/users/dboth)
-
-How to program with Bash: Loops
-======
-Learn how to use loops for performing iterative operations, in the final
-article in this three-part series on programming with Bash.
-![arrows cycle symbol for failing faster][1]
-
-Bash is a powerful programming language, one perfectly designed for use on the command line and in shell scripts. This three-part series, based on my [three-volume Linux self-study course][2], explores using Bash as a programming language on the command-line interface (CLI).
-
-The [first article][3] in this series explored some simple command-line programming with Bash, including using variables and control operators. The [second article][4] looked into the types of file, string, numeric, and miscellaneous logical operators that provide execution-flow control logic and different types of shell expansions in Bash. This third (and final) article examines the use of loops for performing various types of iterative operations and ways to control those loops.
-
-### Loops
-
-Every programming language I have ever used has at least a couple types of loop structures that provide various capabilities to perform repetitive operations. I use the for loop quite often but I also find the while and until loops useful.
-
-#### for loops
-
-Bash's implementation of the **for** command is, in my opinion, a bit more flexible than most because it can handle non-numeric values; in contrast, for example, the standard C language **for** loop can deal only with numeric values.
-
-The basic structure of the Bash version of the **for** command is simple:
-
-
-```
-`for Var in list1 ; do list2 ; done`
-```
-
-This translates to: "For each value in list1, set the **$Var** to that value and then perform the program statements in list2 using that value; when all of the values in list1 have been used, it is finished, so exit the loop." The values in list1 can be a simple, explicit string of values, or they can be the result of a command substitution (described in the second article in the series). I use this construct frequently.
-
-To try it, ensure that **~/testdir** is still the present working directory (PWD). Clean up the directory, then look at a trivial example of the **for** loop starting with an explicit list of values. This list is a mix of alphanumeric values—but do not forget that all variables are strings and can be treated as such.
-
-
-```
-[student@studentvm1 testdir]$ rm *
-[student@studentvm1 testdir]$ for I in a b c d 1 2 3 4 ; do echo $I ; done
-a
-b
-c
-d
-1
-2
-3
-4
-```
-
-Here is a bit more useful version with a more meaningful variable name:
-
-
-```
-[student@studentvm1 testdir]$ for Dept in "Human Resources" Sales Finance "Information Technology" Engineering Administration Research ; do echo "Department $Dept" ; done
-Department Human Resources
-Department Sales
-Department Finance
-Department Information Technology
-Department Engineering
-Department Administration
-Department Research
-```
-
-Make some directories (and show some progress information while doing so):
-
-
-```
-[student@studentvm1 testdir]$ for Dept in "Human Resources" Sales Finance "Information Technology" Engineering Administration Research ; do echo "Working on Department $Dept" ; mkdir "$Dept" ; done
-Working on Department Human Resources
-Working on Department Sales
-Working on Department Finance
-Working on Department Information Technology
-Working on Department Engineering
-Working on Department Administration
-Working on Department Research
-[student@studentvm1 testdir]$ ll
-total 28
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 Administration
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 Engineering
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 Finance
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 'Human Resources'
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 'Information Technology'
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 Research
-drwxrwxr-x 2 student student 4096 Apr 8 15:45 Sales
-```
-
-The **$Dept** variable must be enclosed in quotes in the **mkdir** statement; otherwise, two-part department names (such as "Information Technology") will be treated as two separate departments. That highlights a best practice I like to follow: all file and directory names should be a single word. Although most modern operating systems can deal with spaces in names, it takes extra work for sysadmins to ensure that those special cases are considered in scripts and CLI programs. (They almost certainly should be considered, even if they're annoying because you never know what files you will have.)
-
-So, delete everything in **~/testdir**—again—and do this one more time:
-
-
-```
-[student@studentvm1 testdir]$ rm -rf * ; ll
-total 0
-[student@studentvm1 testdir]$ for Dept in Human-Resources Sales Finance Information-Technology Engineering Administration Research ; do echo "Working on Department $Dept" ; mkdir "$Dept" ; done
-Working on Department Human-Resources
-Working on Department Sales
-Working on Department Finance
-Working on Department Information-Technology
-Working on Department Engineering
-Working on Department Administration
-Working on Department Research
-[student@studentvm1 testdir]$ ll
-total 28
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Administration
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Engineering
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Finance
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Human-Resources
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Information-Technology
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Research
-drwxrwxr-x 2 student student 4096 Apr 8 15:52 Sales
-```
-
-Suppose someone asks for a list of all RPMs on a particular Linux computer and a short description of each. This happened to me when I worked for the State of North Carolina. Since open source was not "approved" for use by state agencies at that time, and I only used Linux on my desktop computer, the pointy-haired bosses (PHBs) needed a list of each piece of software that was installed on my computer so that they could "approve" an exception.
-
-How would you approach that? Here is one way, starting with the knowledge that the **rpm –qa** command provides a complete description of an RPM, including the two items the PHBs want: the software name and a brief summary.
-
-Build up to the final result one step at a time. First, list all RPMs:
-
-
-```
-[student@studentvm1 testdir]$ rpm -qa
-perl-HTTP-Message-6.18-3.fc29.noarch
-perl-IO-1.39-427.fc29.x86_64
-perl-Math-Complex-1.59-429.fc29.noarch
-lua-5.3.5-2.fc29.x86_64
-java-11-openjdk-headless-11.0.ea.28-2.fc29.x86_64
-util-linux-2.32.1-1.fc29.x86_64
-libreport-fedora-2.9.7-1.fc29.x86_64
-rpcbind-1.2.5-0.fc29.x86_64
-libsss_sudo-2.0.0-5.fc29.x86_64
-libfontenc-1.1.3-9.fc29.x86_64
-<snip>
-```
-
-Add the **sort** and **uniq** commands to sort the list and print the unique ones (since it's possible that some RPMs with identical names are installed):
-
-
-```
-[student@studentvm1 testdir]$ rpm -qa | sort | uniq
-a2ps-4.14-39.fc29.x86_64
-aajohan-comfortaa-fonts-3.001-3.fc29.noarch
-abattis-cantarell-fonts-0.111-1.fc29.noarch
-abiword-3.0.2-13.fc29.x86_64
-abrt-2.11.0-1.fc29.x86_64
-abrt-addon-ccpp-2.11.0-1.fc29.x86_64
-abrt-addon-coredump-helper-2.11.0-1.fc29.x86_64
-abrt-addon-kerneloops-2.11.0-1.fc29.x86_64
-abrt-addon-pstoreoops-2.11.0-1.fc29.x86_64
-abrt-addon-vmcore-2.11.0-1.fc29.x86_64
-<snip>
-```
-
-Since this gives the correct list of RPMs you want to look at, you can use this as the input list to a loop that will print all the details of each RPM:
-
-
-```
-`[student@studentvm1 testdir]$ for RPM in `rpm -qa | sort | uniq` ; do rpm -qi $RPM ; done`
-```
-
-This code produces way more data than you want. Note that the loop is complete. The next step is to extract only the information the PHBs requested. So, add an **egrep** command, which is used to select **^Name** or **^Summary**. The carat (**^**) specifies the beginning of the line; thus, any line with Name or Summary at the beginning of the line is displayed.
-
-
-```
-[student@studentvm1 testdir]$ for RPM in `rpm -qa | sort | uniq` ; do rpm -qi $RPM ; done | egrep -i "^Name|^Summary"
-Name : a2ps
-Summary : Converts text and other types of files to PostScript
-Name : aajohan-comfortaa-fonts
-Summary : Modern style true type font
-Name : abattis-cantarell-fonts
-Summary : Humanist sans serif font
-Name : abiword
-Summary : Word processing program
-Name : abrt
-Summary : Automatic bug detection and reporting tool
-<snip>
-```
-
-You can try **grep** instead of **egrep** in the command above, but it will not work. You could also pipe the output of this command through the **less** filter to explore the results. The final command sequence looks like this:
-
-
-```
-`[student@studentvm1 testdir]$ for RPM in `rpm -qa | sort | uniq` ; do rpm -qi $RPM ; done | egrep -i "^Name|^Summary" > RPM-summary.txt`
-```
-
-This command-line program uses pipelines, redirection, and a **for** loop—all on a single line. It redirects the output of your little CLI program to a file that can be used in an email or as input for other purposes.
-
-This process of building up the program one step at a time allows you to see the results of each step and ensure that it is working as you expect and provides the desired results.
-
-From this exercise, the PHBs received a list of over 1,900 separate RPM packages. I seriously doubt that anyone read that list. But I gave them exactly what they asked for, and I never heard another word from them about it.
-
-### Other loops
-
-There are two more types of loop structures available in Bash: the **while** and **until** structures, which are very similar to each other in both syntax and function. The basic syntax of these loop structures is simple:
-
-
-```
-`while [ expression ] ; do list ; done`
-```
-
-and
-
-
-```
-`until [ expression ] ; do list ; done`
-```
-
-The logic of the first reads: "While the expression evaluates as true, execute the list of program statements. When the expression evaluates as false, exit from the loop." And the second: "Until the expression evaluates as true, execute the list of program statements. When the expression evaluates as true, exit from the loop."
-
-#### While loop
-
-The **while** loop is used to execute a series of program statements while (so long as) the logical expression evaluates as true. Your PWD should still be **~/testdir**.
-
-The simplest form of the **while** loop is one that runs forever. The following form uses the true statement to always generate a "true" return code. You could also use a simple "1"—and that would work just the same—but this illustrates the use of the true statement:
-
-
-```
-[student@studentvm1 testdir]$ X=0 ; while [ true ] ; do echo $X ; X=$((X+1)) ; done | head
-0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-[student@studentvm1 testdir]$
-```
-
-This CLI program should make more sense now that you have studied its parts. First, it sets **$X** to zero in case it has a value left over from a previous program or CLI command. Then, since the logical expression **[ true ]** always evaluates to 1, which is true, the list of program instructions between **do** and **done** is executed forever—or until you press **Ctrl+C** or otherwise send a signal 2 to the program. Those instructions are an arithmetic expansion that prints the current value of **$X** and then increments it by one.
-
-One of the tenets of [_The Linux Philosophy for Sysadmins_][5] is to strive for elegance, and one way to achieve elegance is simplicity. You can simplify this program by using the variable increment operator, **++**. In the first instance, the current value of the variable is printed, and then the variable is incremented. This is indicated by placing the **++** operator after the variable:
-
-
-```
-[student@studentvm1 ~]$ X=0 ; while [ true ] ; do echo $((X++)) ; done | head
-0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-```
-
-Now delete **| head** from the end of the program and run it again.
-
-In this version, the variable is incremented before its value is printed. This is specified by placing the **++** operator before the variable. Can you see the difference?
-
-
-```
-[student@studentvm1 ~]$ X=0 ; while [ true ] ; do echo $((++X)) ; done | head
-1
-2
-3
-4
-5
-6
-7
-8
-9
-```
-
-You have reduced two statements into a single one that prints the value of the variable and increments that value. There is also a decrement operator, **\--**.
-
-You need a method for stopping the loop at a specific number. To accomplish that, change the true expression to an actual numeric evaluation expression. Have the program loop to 5 and stop. In the example code below, you can see that **-le** is the logical numeric operator for "less than or equal to." This means: "So long as **$X** is less than or equal to 5, the loop will continue. When **$X** increments to 6, the loop terminates."
-
-
-```
-[student@studentvm1 ~]$ X=0 ; while [ $X -le 5 ] ; do echo $((X++)) ; done
-0
-1
-2
-3
-4
-5
-[student@studentvm1 ~]$
-```
-
-#### Until loop
-
-The **until** command is very much like the **while** command. The difference is that it will continue to loop until the logical expression evaluates to "true." Look at the simplest form of this construct:
-
-
-```
-[student@studentvm1 ~]$ X=0 ; until false ; do echo $((X++)) ; done | head
-0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-[student@studentvm1 ~]$
-```
-
-It uses a logical comparison to count to a specific value:
-
-
-```
-[student@studentvm1 ~]$ X=0 ; until [ $X -eq 5 ] ; do echo $((X++)) ; done
-0
-1
-2
-3
-4
-[student@studentvm1 ~]$ X=0 ; until [ $X -eq 5 ] ; do echo $((++X)) ; done
-1
-2
-3
-4
-5
-[student@studentvm1 ~]$
-```
-
-### Summary
-
-This series has explored many powerful tools for building Bash command-line programs and shell scripts. But it has barely scratched the surface on the many interesting things you can do with Bash; the rest is up to you.
-
-I have discovered that the best way to learn Bash programming is to do it. Find a simple project that requires multiple Bash commands and make a CLI program out of them. Sysadmins do many tasks that lend themselves to CLI programming, so I am sure that you will easily find tasks to automate.
-
-Many years ago, despite being familiar with other shell languages and Perl, I made the decision to use Bash for all of my sysadmin automation tasks. I have discovered that—sometimes with a bit of searching—I have been able to use Bash to accomplish everything I need.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/programming-bash-loops
-
-作者：[David Both][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/dboth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/fail_progress_cycle_momentum_arrow.png?itok=q-ZFa_Eh (arrows cycle symbol for failing faster)
-[2]: http://www.both.org/?page_id=1183
-[3]: https://opensource.com/article/19/10/programming-bash-part-1
-[4]: https://opensource.com/article/19/10/programming-bash-part-2
-[5]: https://www.apress.com/us/book/9781484237298
diff --git a/sources/tech/20191028 How to remove duplicate lines from files with awk.md b/sources/tech/20191028 How to remove duplicate lines from files with awk.md
deleted file mode 100644
index fea53c85a9..0000000000
--- a/sources/tech/20191028 How to remove duplicate lines from files with awk.md
+++ /dev/null
@@ -1,243 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (lxbwolf)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to remove duplicate lines from files with awk)
-[#]: via: (https://opensource.com/article/19/10/remove-duplicate-lines-files-awk)
-[#]: author: (Lazarus Lazaridis https://opensource.com/users/iridakos)
-
-How to remove duplicate lines from files with awk
-======
-Learn how to use awk '!visited[$0]++' without sorting or changing their
-order.
-![Coding on a computer][1]
-
-Suppose you have a text file and you need to remove all of its duplicate lines.
-
-### TL;DR
-
-To remove the duplicate lines while _preserving their order in the file_, use:
-
-
-```
-`awk '!visited[$0]++' your_file > deduplicated_file`
-```
-
-### How it works
-
-The script keeps an associative array with _indices_ equal to the unique lines of the file and _values_ equal to their occurrences. For each line of the file, if the line occurrences are zero, then it increases them by one and _prints the line_, otherwise, it just increases the occurrences _without printing the line_.
-
-I was not familiar with **awk**, and I wanted to understand how this can be accomplished with such a short script (**awk**ward). I did my research, and here is what is going on:
-
- * The awk "script" **!visited[$0]++** is executed for _each line_ of the input file.
- * **visited[]** is a variable of type [associative array][2] (a.k.a. [Map][3]). We don't have to initialize it because **awk** will do it the first time we access it.
- * The **$0** variable holds the contents of the line currently being processed.
- * **visited[$0]** accesses the value stored in the map with a key equal to **$0** (the line being processed), a.k.a. the occurrences (which we set below).
- * The **!** negates the occurrences' value:
- * In awk, [any nonzero numeric value or any nonempty string value is true][4].
- * By default, [variables are initialized to the empty string][5], which is zero if converted to a number.
- * That being said:
- * If **visited[$0]** returns a number greater than zero, this negation is resolved to **false**.
- * If **visited[$0]** returns a number equal to zero or an empty string, this negation is resolved to **true**.
- * The **++** operation increases the variable's value (**visited[$0]**) by one.
- * If the value is empty, **awk** converts it to **0** (number) automatically and then it gets increased.
- * **Note:** The operation is executed after we access the variable's value.
-
-
-
-Summing up, the whole expression evaluates to:
-
- * **true** if the occurrences are zero/empty string
- * **false** if the occurrences are greater than zero
-
-
-
-**awk** statements consist of a [_pattern-expression_ and an _associated action_][6].
-
-
-```
-` { }`
-```
-
-If the pattern succeeds, then the associated action is executed. If we don't provide an action, **awk**, by default, **print**s the input.
-
-> An omitted action is equivalent to **{ print $0 }**.
-
-Our script consists of one **awk** statement with an expression, omitting the action. So this:
-
-
-```
-`awk '!visited[$0]++' your_file > deduplicated_file`
-```
-
-is equivalent to this:
-
-
-```
-`awk '!visited[$0]++ { print $0 }' your_file > deduplicated_file`
-```
-
-For every line of the file, if the expression succeeds, the line is printed to the output. Otherwise, the action is not executed, and nothing is printed.
-
-### Why not use the **uniq** command?
-
-The **uniq** command removes only the _adjacent duplicate lines_. Here's a demonstration:
-
-
-```
-$ cat test.txt
-A
-A
-A
-B
-B
-B
-A
-A
-C
-C
-C
-B
-B
-A
-$ uniq < test.txt
-A
-B
-A
-C
-B
-A
-```
-
-### Other approaches
-
-#### Using the sort command
-
-We can also use the following [**sort**][7] command to remove the duplicate lines, but _the line order is not preserved_.
-
-
-```
-`sort -u your_file > sorted_deduplicated_file`
-```
-
-#### Using cat, sort, and cut
-
-The previous approach would produce a de-duplicated file whose lines would be sorted based on the contents. [Piping a bunch of commands][8] can overcome this issue:
-
-
-```
-`cat -n your_file | sort -uk2 | sort -nk1 | cut -f2-`
-```
-
-##### How it works
-
-Suppose we have the following file:
-
-
-```
-abc
-ghi
-abc
-def
-xyz
-def
-ghi
-klm
-```
-
-**cat -n test.txt** prepends the order number in each line.
-
-
-```
-1 abc
-2 ghi
-3 abc
-4 def
-5 xyz
-6 def
-7 ghi
-8 klm
-```
-
-**sort -uk2** sorts the lines based on the second column (**k2** option) and keeps only the first occurrence of the lines with the same second column value (**u** option).
-
-
-```
-1 abc
-4 def
-2 ghi
-8 klm
-5 xyz
-```
-
-**sort -nk1** sorts the lines based on their first column (**k1** option) treating the column as a number (**-n** option).
-
-
-```
-1 abc
-2 ghi
-4 def
-5 xyz
-8 klm
-```
-
-Finally, **cut -f2-** prints each line starting from the second column until its end (**-f2-** option: _Note the **-** suffix, which instructs it to include the rest of the line_).
-
-
-```
-abc
-ghi
-def
-xyz
-klm
-```
-
-### References
-
- * [The GNU awk user's guide][9]
- * [Arrays in awk][2]
- * [Awk—Truth values][4]
- * [Awk expressions][5]
- * [How can I delete duplicate lines in a file in Unix?][10]
- * [Remove duplicate lines without sorting [duplicate]][11]
- * [How does awk '!a[$0]++' work?][12]
-
-
-
-That's all. Cat photo.
-
-![Duplicate cat][13]
-
-* * *
-
-_This article originally appeared on the iridakos blog by [Lazarus Lazaridis][14] under a [CC BY-NC 4.0 License][15] and is republished with the author's permission._
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/remove-duplicate-lines-files-awk
-
-作者：[Lazarus Lazaridis][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/iridakos
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_laptop_hack_work.png?itok=aSpcWkcl (Coding on a computer)
-[2]: http://kirste.userpage.fu-berlin.de/chemnet/use/info/gawk/gawk_12.html
-[3]: https://en.wikipedia.org/wiki/Associative_array
-[4]: https://www.gnu.org/software/gawk/manual/html_node/Truth-Values.html
-[5]: https://ftp.gnu.org/old-gnu/Manuals/gawk-3.0.3/html_chapter/gawk_8.html
-[6]: http://kirste.userpage.fu-berlin.de/chemnet/use/info/gawk/gawk_9.html
-[7]: http://man7.org/linux/man-pages/man1/sort.1.html
-[8]: https://stackoverflow.com/a/20639730/2292448
-[9]: https://www.gnu.org/software/gawk/manual/html_node/
-[10]: https://stackoverflow.com/questions/1444406/how-can-i-delete-duplicate-lines-in-a-file-in-unix
-[11]: https://stackoverflow.com/questions/11532157/remove-duplicate-lines-without-sorting
-[12]: https://unix.stackexchange.com/questions/159695/how-does-awk-a0-work/159734#159734
-[13]: https://opensource.com/sites/default/files/uploads/duplicate-cat.jpg (Duplicate cat)
-[14]: https://iridakos.com/about/
-[15]: http://creativecommons.org/licenses/by-nc/4.0/
diff --git a/sources/tech/20191101 Awk one-liners and scripts to help you sort text files.md b/sources/tech/20191101 Awk one-liners and scripts to help you sort text files.md
deleted file mode 100644
index 2ce53e1d7e..0000000000
--- a/sources/tech/20191101 Awk one-liners and scripts to help you sort text files.md
+++ /dev/null
@@ -1,254 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Awk one-liners and scripts to help you sort text files)
-[#]: via: (https://opensource.com/article/19/11/how-sort-awk)
-[#]: author: (Seth Kenlon https://opensource.com/users/seth)
-
-Awk one-liners and scripts to help you sort text files
-======
-Awk is a powerful tool for doing tasks that might otherwise be left to
-other common utilities, including sort.
-![Green graph of measurements][1]
-
-Awk is the ubiquitous Unix command for scanning and processing text containing predictable patterns. However, because it features functions, it's also justifiably called a programming language.
-
-Confusingly, there is more than one awk. (Or, if you believe there can be only one, then there are several clones.) There's **awk**, the original program written by Aho, Weinberger, and Kernighan, and then there's **nawk**, **mawk**, and the GNU version, **gawk**. The GNU version of awk is a highly portable, free software version of the utility with several unique features, so this article is about GNU awk.
-
-While its official name is gawk, on GNU+Linux systems it's aliased to awk and serves as the default version of that command. On other systems that don't ship with GNU awk, you must install it and refer to it as gawk, rather than awk. This article uses the terms awk and gawk interchangeably.
-
-Being both a command and a programming language makes awk a powerful tool for tasks that might otherwise be left to **sort**, **cut**, **uniq**, and other common utilities. Luckily, there's lots of room in open source for redundancy, so if you're faced with the question of whether or not to use awk, the answer is probably a solid "maybe."
-
-The beauty of awk's flexibility is that if you've already committed to using awk for a task, then you can probably stay in awk no matter what comes up along the way. This includes the eternal need to sort data in a way other than the order it was delivered to you.
-
-### Sample set
-
-Before exploring awk's sorting methods, generate a sample dataset to use. Keep it simple so that you don't get distracted by edge cases and unintended complexity. This is the sample set this article uses:
-
-
-```
-Aptenodytes;forsteri;Miller,JF;1778;Emperor
-Pygoscelis;papua;Wagler;1832;Gentoo
-Eudyptula;minor;Bonaparte;1867;Little Blue
-Spheniscus;demersus;Brisson;1760;African
-Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
-Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
-Torvaldis;linux;Ewing,L;1996;Tux
-```
-
-It's a small dataset, but it offers a good variety of data types:
-
- * A genus and species name, which are associated with one another but considered separate
- * A surname, sometimes with first initials after a comma
- * An integer representing a date
- * An arbitrary term
- * All fields separated by semi-colons
-
-
-
-Depending on your educational background, you may consider this a 2D array or a table or just a line-delimited collection of data. How you think of it is up to you, because awk doesn't expect anything more than text. It's up to you to tell awk how you want to parse it.
-
-### The sort cheat
-
-If you just want to sort a text dataset by a specific, definable field (think of a "cell" in a spreadsheet), then you can use the [sort command][2].
-
-### Fields and records
-
-Regardless of the format of your input, you must find patterns in it so that you can focus on the parts of the data that are important to you. In this example, the data is delimited by two factors: lines and fields. Each new line represents a new _record_, as you would likely see in a spreadsheet or database dump. Within each line, there are distinct _fields_ (think of them as cells in a spreadsheet) that are separated by semicolons (;).
-
-Awk processes one record at a time, so while you're structuring the instructions you will give to awk, you can focus on just one line. Establish what you want to do with one line, then test it (either mentally or with awk) on the next line and a few more. You'll end up with a good hypothesis on what your awk script must do in order to provide you with the data structure you want.
-
-In this case, it's easy to see that each field is separated by a semicolon. For simplicity's sake, assume you want to sort the list by the very first field of each line.
-
-Before you can sort, you must be able to focus awk on just the first field of each line, so that's the first step. The syntax of an awk command in a terminal is **awk**, followed by relevant options, followed by your awk command, and ending with the file of data you want to process.
-
-
-```
-$ awk --field-separator=";" '{print $1;}' penguins.list
-Aptenodytes
-Pygoscelis
-Eudyptula
-Spheniscus
-Megadyptes
-Eudyptes
-Torvaldis
-```
-
-Because the field separator is a character that has special meaning to the Bash shell, you must enclose the semicolon in quotes or precede it with a backslash. This command is useful only to prove that you can focus on a specific field. You can try the same command using the number of another field to view the contents of another "column" of your data:
-
-
-```
-$ awk --field-separator=";" '{print $3;}' penguins.list
-Miller,JF
-Wagler
-Bonaparte
-Brisson
-Milne-Edwards
-Viellot
-Ewing,L
-```
-
-Nothing has been sorted yet, but this is good groundwork.
-
-### Scripting
-
-Awk is more than just a command; it's a programming language with indices and arrays and functions. That's significant because it means you can grab a list of fields you want to sort by, store the list in memory, process it, and then print the resulting data. For a complex series of actions such as this, it's easier to work in a text file, so create a new file called **sort.awk** and enter this text:
-
-
-```
-#!/bin/gawk -f
-
-BEGIN {
- FS=";";
-}
-```
-
-This establishes the file as an awk script that executes the lines contained in the file.
-
-The **BEGIN** statement is a special setup function provided by awk for tasks that need to occur only once. Defining the built-in variable **FS**, which stands for _field separator_ and is the same value you set in your awk command with **\--field-separator**, only needs to happen once, so it's included in the **BEGIN** statement.
-
-#### Arrays in awk
-
-You already know how to gather the values of a specific field by using the **$** notation along with the field number, but in this case, you need to store it in an array rather than print it to the terminal. This is done with an awk array. The important thing about an awk array is that it contains keys and values. Imagine an array about this article; it would look something like this: **author:"seth",title:"How to sort with awk",length:1200**. Elements like **author** and **title** and **length** are keys, with the following contents being values.
-
-The advantage to this in the context of sorting is that you can assign any field as the key and any record as the value, and then use the built-in awk function **asorti()** (sort by index) to sort by the key. For now, assume arbitrarily that you _only_ want to sort by the second field.
-
-Awk statements _not_ preceded by the special keywords **BEGIN** or **END** are loops that happen at each record. This is the part of the script that scans the data for patterns and processes it accordingly. Each time awk turns its attention to a record, statements in **{}** (unless preceded by **BEGIN** or **END**) are executed.
-
-To add a key and value to an array, create a variable (in this example script, I call it **ARRAY**, which isn't terribly original, but very clear) containing an array, and then assign it a key in brackets and a value with an equals sign (**=**).
-
-
-```
-{ # dump each field into an array
- ARRAY[$2] = $R;
-}
-```
-
-In this statement, the contents of the second field (**$2**) are used as the key term, and the current record (**$R**) is used as the value.
-
-### The asorti() function
-
-In addition to arrays, awk has several basic functions that you can use as quick and easy solutions for common tasks. One of the functions introduced in GNU awk, **asorti()**, provides the ability to sort an array by key (or _index_) or value.
-
-You can only sort the array once it has been populated, meaning that this action must not occur with every new record but only the final stage of your script. For this purpose, awk provides the special **END** keyword. The inverse of **BEGIN**, an **END** statement happens only once and only after all records have been scanned.
-
-Add this to your script:
-
-
-```
-END {
- asorti(ARRAY,SARRAY);
- # get length
- j = length(SARRAY);
-
- for (i = 1; i <= j; i++) {
- printf("%s %s\n", SARRAY[i],ARRAY[SARRAY[i]])
- }
-}
-```
-
-The **asorti()** function takes the contents of **ARRAY**, sorts it by index, and places the results in a new array called **SARRAY** (an arbitrary name I invented for this article, meaning _Sorted ARRAY_).
-
-Next, the variable **j** (another arbitrary name) is assigned the results of the **length()** function, which counts the number of items in **SARRAY**.
-
-Finally, use a **for** loop to iterate through each item in **SARRAY** using the **printf()** function to print each key, followed by the corresponding value of that key in **ARRAY**.
-
-### Running the script
-
-To run your awk script, make it executable:
-
-
-```
-`$ chmod +x sorter.awk`
-```
-
-And then run it against the **penguin.list** sample data:
-
-
-```
-$ ./sorter.awk penguins.list
-antipodes Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
-chrysocome Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
-demersus Spheniscus;demersus;Brisson;1760;African
-forsteri Aptenodytes;forsteri;Miller,JF;1778;Emperor
-linux Torvaldis;linux;Ewing,L;1996;Tux
-minor Eudyptula;minor;Bonaparte;1867;Little Blue
-papua Pygoscelis;papua;Wagler;1832;Gentoo
-```
-
-As you can see, the data is sorted by the second field.
-
-This is a little restrictive. It would be better to have the flexibility to choose at runtime which field you want to use as your sorting key so you could use this script on any dataset and get meaningful results.
-
-### Adding command options
-
-You can add a command variable to an awk script by using the literal value **var** in your script. Change your script so that your iterative clause uses **var** when creating your array:
-
-
-```
-{ # dump each field into an array
- ARRAY[$var] = $R;
-}
-```
-
-Try running the script so that it sorts by the third field by using the **-v var** option when you execute it:
-
-
-```
-$ ./sorter.awk -v var=3 penguins.list
-Bonaparte Eudyptula;minor;Bonaparte;1867;Little Blue
-Brisson Spheniscus;demersus;Brisson;1760;African
-Ewing,L Torvaldis;linux;Ewing,L;1996;Tux
-Miller,JF Aptenodytes;forsteri;Miller,JF;1778;Emperor
-Milne-Edwards Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
-Viellot Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
-Wagler Pygoscelis;papua;Wagler;1832;Gentoo
-```
-
-### Fixes
-
-This article has demonstrated how to sort data in pure GNU awk. The script can be improved so, if it's useful to you, spend some time researching [awk functions][3] on gawk's man page and customizing the script for better output.
-
-Here is the complete script so far:
-
-
-```
-#!/usr/bin/awk -f
-# GPLv3 appears here
-# usage: ./sorter.awk -v var=NUM FILE
-
-BEGIN { FS=";"; }
-
-{ # dump each field into an array
- ARRAY[$var] = $R;
-}
-
-END {
- asorti(ARRAY,SARRAY);
- # get length
- j = length(SARRAY);
-
- for (i = 1; i <= j; i++) {
- printf("%s %s\n", SARRAY[i],ARRAY[SARRAY[i]])
- }
-}
-```
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/11/how-sort-awk
-
-作者：[Seth Kenlon][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/seth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/metrics_lead-steps-measure.png?itok=DG7rFZPk (Green graph of measurements)
-[2]: https://opensource.com/article/19/10/get-sorted-sort
-[3]: https://www.gnu.org/software/gawk/manual/html_node/Built_002din.html#Built_002din
diff --git a/sources/tech/20191115 How to port an awk script to Python.md b/sources/tech/20191115 How to port an awk script to Python.md
deleted file mode 100644
index 1d9e5ba354..0000000000
--- a/sources/tech/20191115 How to port an awk script to Python.md
+++ /dev/null
@@ -1,212 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (wxy)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to port an awk script to Python)
-[#]: via: (https://opensource.com/article/19/11/awk-to-python)
-[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
-
-How to port an awk script to Python
-======
-Porting an awk script to Python is more about code style than
-transliteration.
-![Woman sitting in front of her laptop][1]
-
-Scripts are potent ways to solve a problem repeatedly, and awk is an excellent language for writing them. It excels at easy text processing in particular, and it can bring you through some complicated rewriting of config files or reformatting file names in a directory.
-
-### When to move from awk to Python
-
-At some point, however, awk's limitations start to show. It has no real concept of breaking files into modules, it lacks quality error reporting, and it's missing other things that are now considered fundamentals of how a language works. When these rich features of a programming language are helpful to maintain a critical script, porting becomes a good option.
-
-My favorite modern programming language that is perfect for porting awk is Python.
-
-Before porting an awk script to Python, it is often worthwhile to consider its original context. For example, because of awk's limitations, the awk code is commonly called from a Bash script and includes some calls to other command-line favorites like sed, sort, and the gang. It's best to convert all of it into one coherent Python program. Other times, the script makes overly broad assumptions; for example, the code might allow for any number of files, even though it's run with only one in practice.
-
-After carefully considering the context and determining the thing to substitute with Python, it is time to write code.
-
-### Standard awk to Python functionality
-
-The following Python functionality is useful to remember:
-
-
-```
-with open(some_file_name) as fpin:
- for line in fpin:
- pass # do something with line
-```
-
-This code will loop through a file line-by-line and process the lines.
-
-If you want to access a line number (equivalent to awk's **NR**), you can use the following code:
-
-
-```
-with open(some_file_name) as fpin:
- for nr, line in enumerate(fpin):
- pass # do something with line
-```
-
-### awk-like behavior over multiple files in Python
-
-If you need to be able to iterate through any number of files while keeping a persistent count of the number of lines (like awk's **FNR**), this loop can do it:
-
-
-```
-def awk_like_lines(list_of_file_names):
- def _all_lines():
- for filename in list_of_file_names:
- with open(filename) as fpin:
- yield from fpin
- yield from enumerate(_all_lines())
-```
-
-This syntax uses Python's _generators_ and **yield from** to build an _iterator_ that loops through all lines and keeps a persistent count.
-
-If you need the equivalent of both **FNR** and **NR**, here is a more sophisticated loop:
-
-
-```
-def awk_like_lines(list_of_file_names):
- def _all_lines():
- for filename in list_of_file_names:
- with open(filename) as fpin:
- yield from enumerate(fpin)
- for nr, (fnr, line) in _all_lines:
- yield nr, fnr, line
-```
-
-### More complex awk functionality with FNR, NR, and line
-
-The question remains if you need all three: **FNR**, **NR**, and **line**. If you really do, using a three-tuple where two of the items are numbers can lead to confusion. Named parameters can make this code easier to read, so it's better to use a **dataclass**:
-
-
-```
-import dataclass
-
-@dataclass.dataclass(frozen=True)
-class AwkLikeLine:
- content: str
- fnr: int
- nr: int
-
-def awk_like_lines(list_of_file_names):
- def _all_lines():
- for filename in list_of_file_names:
- with open(filename) as fpin:
- yield from enumerate(fpin)
- for nr, (fnr, line) in _all_lines:
- yield AwkLikeLine(nr=nr, fnr=fnr, line=line)
-```
-
-You might wonder, why not start with this approach? The reason to start elsewhere is that this is almost always too complicated. If your goal is to make a generic library that makes porting awk to Python easier, then consider doing so. But writing a loop that gets you exactly what you need for a specific case is usually easier to do and easier to understand (and thus maintain).
-
-### Understanding awk fields
-
-Once you have a string that corresponds to a line, if you are converting an awk program, you often want to break it up into _fields_. Python has several ways of doing that. This will return a list of strings, splitting the line on any number of consecutive whitespaces:
-
-
-```
-`line.split()`
-```
-
-If another field separator is needed, something like this will split the line by **:**; the **rstrip** method is needed to remove the last newline:
-
-
-```
-`line.rstrip("\n").split(":")`
-```
-
-After doing the following, the list **parts** will have the broken-up string:
-
-
-```
-`parts = line.rstrip("\n").split(":")`
-```
-
-This split is good for choosing what to do with the parameters, but we are in an [off-by-one error][2] scenario. Now **parts[0]** will correspond to awk's **$1**, **parts[1]** will correspond to awk's **$2**, etc. This off-by-one is because awk starts counting the "fields" from 1, while Python counts from 0. In awk's **$0** is the whole line -- equivalent to **line.rstrip("\n") **and awk's **NF** (number of fields) is more easily retrieved as **len(parts)**.
-
-### Porting awk fields in Python
-
-As an example, let's convert the one-liner from "[How to remove duplicate lines from files with awk][3]" to Python.
-
-The original in awk is:
-
-
-```
-`awk '!visited[$0]++' your_file > deduplicated_file`
-```
-
-An "authentic" Python conversion would be:
-
-
-```
-import collections
-import sys
-
-visited = collections.defaultdict(int)
-for line in open("your_file"):
- did_visit = visited[line]
- visited[line] += 1
- if not did_visit:
- sys.stdout.write(line)
-```
-
-However, Python has more data structures than awk. Instead of _counting_ visits (which we do not use, except to know whether we saw a line), why not record the visited lines?
-
-
-```
-import sys
-
-visited = set()
-for line in open("your_file"):
- if line in visited:
- continue
- visited.add(line)
- sys.stdout.write(line)
-```
-
-### Making Pythonic awk code
-
-The Python community advocates for writing Pythonic code, which means it follows a commonly agreed-upon code style. An even more Pythonic approach will separate the concerns of _uniqueness_ and _input/output_. This change would make it easier to unit test your code:
-
-
-```
-def unique_generator(things):
- visited = set()
- for thing in things:
- if thing in visited:
- continue
- visited.add(things)
- yield thing
-
-import sys
-
-for line in unique_generator(open("your_file")):
- sys.stdout.write(line)
-```
-
-Putting all logic away from the input/output code leads to better separation of concerns and more usability and testability of code.
-
-### Conclusion: Python can be a good choice
-
-Porting an awk script to Python is often more a matter of reimplementing the core requirements while thinking about proper Pythonic code style than a slavish transliteration of condition/action by condition/action. Take the original context into account and produce a quality Python solution. While there are times when a Bash one-liner with awk can get the job done, Python coding is a path toward more easily maintainable code.
-
-Also, if you're writing awk scripts, I am confident you can learn Python as well! Let me know if you have any questions in the comments.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/11/awk-to-python
-
-作者：[Moshe Zadka][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/moshez
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_women_computing_4.png?itok=VGZO8CxT (Woman sitting in front of her laptop)
-[2]: https://en.wikipedia.org/wiki/Off-by-one_error
-[3]: https://opensource.com/article/19/10/remove-duplicate-lines-files-awk
diff --git a/sources/tech/20191118 How internet security works- TLS, SSL, and CA.md b/sources/tech/20191118 How internet security works- TLS, SSL, and CA.md
deleted file mode 100644
index 0247b43ef1..0000000000
--- a/sources/tech/20191118 How internet security works- TLS, SSL, and CA.md
+++ /dev/null
@@ -1,57 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (hopefully2333)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How internet security works: TLS, SSL, and CA)
-[#]: via: (https://opensource.com/article/19/11/internet-security-tls-ssl-certificate-authority)
-[#]: author: (Bryant Son https://opensource.com/users/brson)
-
-How internet security works: TLS, SSL, and CA
-======
-What's behind that lock icon in your web browser?
-![Lock][1]
-
-Multiple times every day, you visit websites that ask you to log in with your username or email address and password. Banking websites, social networking sites, email services, e-commerce sites, and news sites are just a handful of the types of sites that use this mechanism.
-
-Every time you sign into one of these sites, you are, in essence, saying, "yes, I trust this website, so I am willing to share my personal information with it." This data may include your name, gender, physical address, email address, and sometimes even credit card information.
-
-But how do you know you can trust a particular website? To put this a different way, what is the website doing to secure your transaction so that you can trust it?
-
-This article aims to demystify the mechanisms that make a website secure. I will start by discussing the web protocols HTTP and HTTPS and the concept of Transport Layer Security (TLS), which is one of the cryptographic protocols in the internet protocol's (IP) layers. Then, I will explain certificate authorities (CAs) and self-signed certificates and how they can help secure a website. Finally, I will introduce some open source tools you can use to create and manage certificates.
-
-## Securing routes through HTTPS
-
-The easiest way to understand a secured website is to see it in action. Fortunately, it is far easier to find a secured website than an unsecured website on the internet today. But, since you are already on Opensource.com, I'll use it as an example. No matter what browser you're using, you should see an icon that looks like a lock next to the address bar. Click on the lock icon, and you should see something similar to this.
-
-![Certificate information][2]
-
-By default, a website is not secure if it uses the HTTP protocol. Adding a certificate configured through the website host to the route can transform the website from an unsecured HTTP site to a secured HTTPS site. The lock icon usually indicates that the site is secured through HTTPS.
-
-Click on Certificate to see the site's CA. Depending on your browser, you may need to download the certificate to see it.
-
-![Certificate information][3]
-
-Here, you can learn something about Opensource.com's certificate. For example, you can see that the CA is DigiCert, and it is given to Red Hat under the name Opensource.com.
-
-This certificate information enables the end user to check that the website is safe to visit.
-
-> WARNING: If you do not see a certificate sign on a website—or if you see a sign that indicates that the website is not secure—please do not log in or do any activity that requires your private data. Doing so is quite dangerous!
-
-If you see a warning sign, which is rare for most publicly facing websites, it usually means that the certificate is expired or uses a self-signed certificate instead of one issued through a trusted CA. Before we get into those topics, I want to explain the TLS and SSL.
-
-## Internet protocols with TLS and SSL
-
-TLS is the current generation of the old Secure Socket Layer (SSL) protocol. The best way to understand this is by examining the different layers of the IP.
-
-![IP layers][4]
-
-There are six layers that make up the internet as we know it today: physical, data, network, transport, security, and application. The physical layer is the base foundation, and it is closest to the actual hardware. The application layer is the most abstract layer and the one closest to the end user. The security layer can be considered a part of the application layer, and TLS and SSL, which are the cryptographic protocols designed to provide communications security over a computer network, are in the security layer.
-
-This process ensures that communication is secure and encrypted when an end user consumes the service.
-
-## Certificate authorities and self-signed certificates
-
-A CA is a trusted organization that can issue a digital certificate.
-
-TLS and SSL can make a connection secure, but the encryption mechanism needs a way to validate it; this is the SSL/TLS certificate. TLS uses a mechanism called asymmetric encryption, which i
diff --git a/sources/tech/20191125 The many faces of awk.md b/sources/tech/20191125 The many faces of awk.md
deleted file mode 100644
index ec0c5b1b09..0000000000
--- a/sources/tech/20191125 The many faces of awk.md
+++ /dev/null
@@ -1,234 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (luuming)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (The many faces of awk)
-[#]: via: (https://www.networkworld.com/article/3454979/the-many-faces-of-awk.html)
-[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
-
-The many faces of awk
-======
-The awk command provides a lot more than simply selecting fields from input strings, including pulling out columns of data, printing simple text, evaluating content – even doing math.
-Thinkstock
-
-If you only use **awk** when you need to select a specific field from lines of text, you might be missing out on a lot of other services that the command can provide. In this post, we'll look at this simple use along with some of the other things that **awk** can do for you and provide some examples.
-
-### Plucking out columns of data
-
-The easiest and most commonly used service that **awk** provides is selecting specific fields from files or from data that is piped to it. With the default of using white space as a field separator, this is very simple.
-
-[[Get regularly scheduled insights by signing up for Network World newsletters.]][1]
-
-```
-$ echo one two three four five | awk ‘{print $4}’
-four
-$ who | awk ‘{print $1}’
-jdoe
-fhenry
-```
-
-White space is any sequence of blanks and tabs. In the commands shown above, **awk** is extracting just the fourth and first fields from the data provided.
-
-[][2]
-
-BrandPost Sponsored by HPE
-
-[Take the Intelligent Route with Consumption-Based Storage][2]
-
-Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
-
-Awk can also pull text from files by just adding the name of the file after the **awk** command.
-
-```
-$ awk '{print $1,$5,$NF}' HelenKellerQuote
-The beautiful heart.
-```
-
-In this case, **awk** has picked out the first, fifth and last words in the single line of test.
-
-The **$NF** specification in the command picks the last piece of text on each line. That is because **NF** represents the number of fields in a line (23) while **$NF** then represents the _value_ of that field ("heart."). The period is included because it's part of the final text string.
-
-Fields can be printed in any order that you might find useful. In this example, we are rearranging the fields in **date** command output.
-
-```
-$ date | awk '{print $4,$3,$2}'
-2019 Nov 22
-```
-
-If you omit the commas between the field designators in an **awk** command, the output will be pushed into a single string.
-
-```
-$ date | awk '{print $4 $3 $2}'
-2019Nov21
-```
-
-If you replace the usual commas with hyphens, **awk** will attempt to subtract one field from another – probably not what you intended. It doesn't take the hyphens as characters to be inserted into the print output. Instead, it puts some of its mathematical prowess into play.
-
-```
-$ date | awk '{print $4-$3-$2}'
-1997
-```
-
-In this case, it's subtracting 22 (the day of the month) from the year (2019) and simply ignoring "Nov".
-
-If you want your output to be separated by something other than white space, you can specify your output separator with **OFS** (output field separator) like this:
-
-```
-$ date | awk '{OFS="-"; print $4,$3,$2}'
-2019-Nov-22
-```
-
-### Printing simple text
-
-You can also use **awk** to simply display some text. Of course, if all you want to do is print a line of text, you'd be better off using an **echo** command. On the other hand, as part of an **awk** script, printing some relevant text can be very useful. Here's a practically useless example:
-
-```
-$ awk 'BEGIN {print "Hello, World" }'
-Hello, World
-```
-
-Here's a more sensible example in which adding a line of text to label your data can help identify what you're looking at:
-
-```
-$ who | awk 'BEGIN {print "Current logins:"} {print $1}'
-Current logins:
-shs
-nemo
-```
-
-### Specifying a field separator
-
-Not all input is going to be separated by white space. If your text is separated by some other character (e.g., commas, colons or semicolons), you can inform **awk** by using the **-F** (input separator) option as shown here:
-
-```
-$ cat testfile
-a:b:c,d:e
-$ awk -F : '{print $2,$3}' testfile
-b c,d
-```
-
-Here's a more useful example – pulling a field from the colon-separated **/etc/passwd** file:
-
-```
-$ awk -F: '{print $1}' /etc/passwd | head -11
-root
-daemon
-bin
-sys
-sync
-games
-man
-lp
-mail
-news
-uucp
-```
-
-### Evaluating content
-
-You can also evaluate fields using **awk**. If you, for example, want to list only _user accounts_ in **/etc/passwd**, you can include a test for the 3rd field. Here we're only going after UIDs that are 1000 and above:
-
-```
-$ awk -F":" ' $3 >= 1000 ' /etc/passwd
-nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
-shs:x:1000:1000:Sandra Henry-Stocker,,,:/home/shs:/bin/bash
-nemo:x:1001:1001:Nemo,,,:/home/nemo:/usr/bin/zsh
-dory:x:1002:1002:Dory,,,:/home/dory:/bin/bash
-...
-```
-
-If you want to add a title for your listing, you can add a BEGIN clause:
-
-```
-$ awk -F":" 'BEGIN {print "user accounts:"} $3 >= 1000 ' /etc/passwd
-user accounts:
-nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
-shs:x:1000:1000:Sandra Henry-Stocker,,,:/home/shs:/bin/bash
-nemo:x:1001:1001:Nemo,,,:/home/nemo:/usr/bin/zsh
-dory:x:1002:1002:Dory,,,:/home/dory:/bin/bash
-```
-
-If you want more than one line in your title, you can separate your intended output lines with "\n" (newline characters).
-
-```
-$ awk -F":" 'BEGIN {print "user accounts\n============="} $3 >= 1000 ' /etc/passwd
-user accounts
-=============
-nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
-shs:x:1000:1000:Sandra Henry-Stocker,,,:/home/shs:/bin/bash
-nemo:x:1001:1001:Nemo,,,:/home/nemo:/usr/bin/zsh
-dory:x:1002:1002:Dory,,,:/home/dory:/bin/bash
-```
-
-### Doing math with awk
-
-**awk** provides a surprising mathematical ability and can calculate square roots, logs, tangents, etc.
-
-Here are a couple examples:
-
-```
-$ awk 'BEGIN {print sqrt(2019)}'
-44.9333
-$ awk 'BEGIN {print log(2019)}'
-7.61036
-```
-
-For more details on **awk**'s mathematical skills, check out [Doing math with awk][3].
-
-### awk scripts
-
-You can also write standalone scripts with **awk**. Here's an example that mimics one of the examples provided earlier, but also counts the number of users with accounts on the system.
-
-```
-#!/usr/bin/awk -f
-
-# This line is a comment
-
-BEGIN {
- printf "%s\n","User accounts:"
- print "=============="
- FS=":"
- n=0
-}
-
-# Now we'll run through the data
-{
- if ($3 >= 1000) {
- print $1
- n ++
- }
-}
-
-END {
- print "=============="
- print n " accounts"
-}
-```
-
-Notice how the BEGIN section, which is run only when the script starts, provides a heading, dictates the field separator and sets up a counter to start with 0. The script also includes an END section which only runs after all the lines in the text provided to the script have been processed. It displays the final count of lines that meet the specification in the middle section (third field is 1,000 or larger)
-
-A long-standing Unix command, **awk** still provides very useful services and remains one of the reasons that I fell in love with Unix many decades ago.
-
-To see **awk** in action, click below.
-
-Join the Network World communities on [Facebook][4] and [LinkedIn][5] to comment on topics that are top of mind.
-
---------------------------------------------------------------------------------
-
-via: https://www.networkworld.com/article/3454979/the-many-faces-of-awk.html
-
-作者：[Sandra Henry-Stocker][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
-[b]: https://github.com/lujun9972
-[1]: https://www.networkworld.com/newsletters/signup.html
-[2]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
-[3]: https://www.networkworld.com/article/2974753/doing-math-with-awk.html
-[4]: https://www.facebook.com/NetworkWorld/
-[5]: https://www.linkedin.com/company/network-world
diff --git a/sources/tech/20191127 Create virtual machines with Cockpit in Fedora.md b/sources/tech/20191127 Create virtual machines with Cockpit in Fedora.md
deleted file mode 100644
index 853ad5c501..0000000000
--- a/sources/tech/20191127 Create virtual machines with Cockpit in Fedora.md
+++ /dev/null
@@ -1,99 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Create virtual machines with Cockpit in Fedora)
-[#]: via: (https://fedoramagazine.org/create-virtual-machines-with-cockpit-in-fedora/)
-[#]: author: (Karlis KavacisPaul W. Frields https://fedoramagazine.org/author/karlisk/https://fedoramagazine.org/author/pfrields/)
-
-Create virtual machines with Cockpit in Fedora
-======
-
-![][1]
-
-This article shows you how to install the software you need to use Cockpit to create and manage virtual machines on Fedora 31. Cockpit is [an interactive admin interface][2] that lets you access and manage systems from any supported web browser. With [virt-manager being deprecated][3] users are encouraged to use Cockpit instead, which is meant to replace it.
-
-Cockpit is an actively developed project, with many plugins available that extend how it works. For example, one such plugin is “Machines,” which interacts with libvirtd and lets users create and manage virtual machines.
-
-### Installing software
-
-The required software prerequisites are _libvirt_, _cockpit_ and _cockpit-machines_. To install them on Fedora 31, run the following command from a terminal [using sudo][4]:
-
-```
-$ sudo dnf install libvirt cockpit cockpit-machines
-```
-
-Cockpit is also included as part of the “Headless Management” package group. This group is useful for a Fedora based server that you only access through a network. In that case, to install it, use this command:
-
-```
-$ sudo dnf groupinstall "Headless Management"
-```
-
-### Setting up Cockpit services
-
-After installing the necessary packages it’s time to enable the services. The _libvirtd_ service runs the virtual machines, while Cockpit has a socket activated service to let you access the Web GUI:
-
-```
-$ sudo systemctl enable libvirtd --now
-$ sudo systemctl enable cockpit.socket --now
-```
-
-This should be enough to run virtual machines and manage them through Cockpit. Optionally, if you want to access and manage your machine from another device on your network, you need to expose the service to the network. To do this, add a new rule in your firewall configuration:
-
-```
-$ sudo firewall-cmd --zone=public --add-service=cockpit --permanent
-$ sudo firewall-cmd --reload
-```
-
-To confirm the services are running and no issues occurred, check the status of the services:
-
-```
-$ sudo systemctl status libvirtd
-$ sudo systemctl status cockpit.socket
-```
-
-At this point everything should be working. The Cockpit web GUI should be available at or . Or, enter the local network IP in a web browser on any other device connected to the same network. (Without SSL certificates setup, you may need to allow a connection from your browser.)
-
-### Creating and installing a machine
-
-Log into the interface using the user name and password for that system. You can also choose whether to allow your password to be used for administrative tasks in this session.
-
-Select _Virtual Machines_ and then select _Create VM_ to build a new box. The console gives you several options:
-
- * Download an OS using Cockpit’s built in library
- * Use install media already downloaded on the system you’re managing
- * Point to a URL for an OS installation tree
- * Boot media over the network via the [PXE][5] protocol
-
-
-
-Enter all the necessary parameters. Then select _Create_ to power up the new virtual machine.
-
-At this point, a graphical console appears. Most modern web browsers let you use your keyboard and mouse to interact with the VM console. Now you can complete your installation and use your new VM, just as you would [via virt-manager in the past][6].
-
-* * *
-
-_Photo by [Miguel Teixeira][7] on [Flickr][8] (CC BY-SA 2.0)._
-
---------------------------------------------------------------------------------
-
-via: https://fedoramagazine.org/create-virtual-machines-with-cockpit-in-fedora/
-
-作者：[Karlis KavacisPaul W. Frields][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://fedoramagazine.org/author/karlisk/https://fedoramagazine.org/author/pfrields/
-[b]: https://github.com/lujun9972
-[1]: https://fedoramagazine.org/wp-content/uploads/2019/11/create-vm-cockpit-816x345.jpg
-[2]: https://cockpit-project.org/
-[3]: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/rhel-8_0_0_release#virtualization_4
-[4]: https://fedoramagazine.org/howto-use-sudo/
-[5]: https://en.wikipedia.org/wiki/Preboot_Execution_Environment
-[6]: https://fedoramagazine.org/full-virtualization-system-on-fedora-workstation-30/
-[7]: https://flickr.com/photos/miguelteixeira/
-[8]: https://flickr.com/photos/miguelteixeira/2964851828/
diff --git a/sources/tech/20191127 How to write a Python web API with Flask.md b/sources/tech/20191127 How to write a Python web API with Flask.md
deleted file mode 100644
index e3d7a7790e..0000000000
--- a/sources/tech/20191127 How to write a Python web API with Flask.md
+++ /dev/null
@@ -1,146 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to write a Python web API with Flask)
-[#]: via: (https://opensource.com/article/19/11/python-web-api-flask)
-[#]: author: (Rachel Waston https://opensource.com/users/rachelwaston)
-
-How to write a Python web API with Flask
-======
-Use Flask, one of the fastest-growing Python frameworks, to fetch data
-from a server, in this quick tutorial.
-![spiderweb diagram][1]
-
-[Python][2] is a high-level, object-oriented programming language known for its simple syntax. It is consistently among the top-rated programming languages for building RESTful APIs.
-
-[Flask][3] is a customizable Python framework that gives developers complete control over how users access data. Flask is a "micro-framework" based on Werkzeug's [WSGI][4] toolkit and Jinja 2's templating engine. It is designed as a web framework for RESTful API development.
-
-Flask is one of the fastest-growing Python frameworks, and popular websites, including Netflix, Pinterest, and LinkedIn, have incorporated Flask into their development stacks. Here's an example of how Flask can permit users to fetch data from a server using the HTTP GET method.
-
-### Set up a Flask application
-
-First, create a structure for your Flask application. You can do this at any location on your system.
-
-
-```
-$ mkdir tutorial
-$ cd tutorial
-$ touch main.py
-$ python3 -m venv env
-$ source env/bin/activate
-(env) $ pip3 install flask-restful
-Collecting flask-restful
-Downloading
-Collecting Flask>=0.8 (from flask-restful)
-[...]
-```
-
-### Import the Flask modules
-
-Next, import the **flask** module and its **flask_restful** library into your **main.py** code:
-
-
-```
-from flask import Flask
-from flask_restful import Resource, Api
-
-app = Flask(__name__)
-api = Api(app)
-
-class Quotes(Resource):
- def get(self):
- return {
- 'William Shakespeare': {
- 'quote': ['Love all,trust a few,do wrong to none',
- 'Some are born great, some achieve greatness, and some greatness thrust upon them.']
- },
- 'Linus': {
- 'quote': ['Talk is cheap. Show me the code.']
- }
- }
-
-api.add_resource(Quotes, '/')
-
-if __name__ == '__main__':
- app.run(debug=True)
-```
-
-### Run the app
-
-Flask includes a built-in HTTP server for testing. Test the simple API you built:
-
-
-```
-(env) $ python main.py
- * Serving Flask app "main" (lazy loading)
- * Environment: production
- WARNING: This is a development server. Do not use it in a production deployment.
- Use a production WSGI server instead.
- * Debug mode: on
- * Running on (Press CTRL+C to quit)
-```
-
-Starting the development server starts your Flask application, which contains a method named **get** to respond to a simple HTTP GET request. You can test it using **wget** or **curl** or any web browser. The URL to use is provided in Flask's output after you start the server.
-
-
-```
-$ curl
-{
- "William Shakespeare": {
- "quote": [
- "Love all,trust a few,do wrong to none",
- "Some are born great, some achieve greatness, and some greatness thrust upon them."
- ]
- },
- "Linus": {
- "quote": [
- "Talk is cheap. Show me the code."
- ]
- }
-}
-```
-
-To see a more complex version of a similar web API using Python and Flask, navigate to the Library of Congress' [Chronicling America][5] website, which provides access to information about historic newspapers and digitized newspaper pages.
-
-### Why use Flask?
-
-Flask has several major benefits:
-
- 1. Python is popular and widely used, so anyone who knows Python can develop for Flask.
- 2. It's lightweight and minimalistic.
- 3. Built with security in mind.
- 4. Great documentation with plenty of clear, working example code.
-
-
-
-There are also some potential drawbacks:
-
- 1. It's lightweight and minimalistic. If you're looking for a framework with lots of bundled libraries and prefabricated components, this may not be your best option.
- 2. If you have to build your own framework around Flask, you might find that the cost of maintaining your customization negates the benefit of using Flask.
-
-
-
-If you're looking to build a web app or API, Flask is a good option to consider. It's powerful and robust, and the project documentation makes it easy to get started. Try it out, evaluate it, and see if it's right for your project.
-
-Learn more in this lesson in Python exception handling and how to do it in a secure manner.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/11/python-web-api-flask
-
-作者：[Rachel Waston][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/rachelwaston
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web-cms-build-howto-tutorial.png?itok=bRbCJt1U (spiderweb diagram)
-[2]: https://www.python.org/
-[3]: https://palletsprojects.com/p/flask/
-[4]: https://en.wikipedia.org/wiki/Web_Server_Gateway_Interface
-[5]: https://chroniclingamerica.loc.gov/about/api
diff --git a/sources/tech/20191203 Why use the Pantheon desktop for Linux Elementary OS.md b/sources/tech/20191203 Why use the Pantheon desktop for Linux Elementary OS.md
deleted file mode 100644
index e1b1fc16c8..0000000000
--- a/sources/tech/20191203 Why use the Pantheon desktop for Linux Elementary OS.md
+++ /dev/null
@@ -1,72 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (geekpi)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Why use the Pantheon desktop for Linux Elementary OS)
-[#]: via: (https://opensource.com/article/19/12/pantheon-linux-desktop)
-[#]: author: (Seth Kenlon https://opensource.com/users/seth)
-
-Why use the Pantheon desktop for Linux Elementary OS
-======
-This article is part of a special series on Linux desktops. Get a
-much-loved Mac OS feature on Linux with the Pantheon desktop for
-Elementary OS.
-![A person programming][1]
-
-Would you pay $20 for a Linux desktop? I would, and in fact, I regularly choose to pay more than that when I download free software! The reason I do this is that open source is worth it. For a copy of [Elementary OS][2], US$ 20 happens to be the default asking price (you can download it for $1 or even $0 if you can't afford anything more). What you get in return is an excellent and heavily curated distribution that ships with its own Pantheon desktop design.
-
-You may find Pantheon included in a software repository, as it is open source, but more likely, you'll have to download and install [Elementary][3] Linux to experience it. If you're not ready to install Elementary on your computer as the main OS, you can install it into a virtual machine, like [GNOME Boxes][4].
-
-The Pantheon desktop is clean, attractive, and features many of the little things many users want in a desktop but could never quite get from the usual Linux desktops.
-
-### Pantheon desktop tour
-
-At first glance, the Pantheon desktop looks a little like Cinnamon or Budgie or the Classic mode of GNOME 3. However, the most exciting features of Pantheon are the smallest touches. It excels in all the places you notice the very least, until that place is the only thing you're looking at one day, and you realize that the way it works has literally improved your quality of life, to say nothing of making your day a lot nicer.
-
-The clearest example of this is **file name highlighting**. For decades, Mac OS has had a much-loved feature whereby you can highlight the displayed name of an important file. People use this feature as a quick visual indicator to tell themselves which file is the "best" version of several, or which file should be sent to a friend, or which file still needs work. They're arbitrary colors and can mean whatever the user wants them to mean. Most importantly, it's noticeable visual metadata.
-
-Users switching from Mac OS tend to miss this feature in GNOME and KDE and every other desktop option Linux has on offer. Pantheon quietly and casually solves that problem.
-
-![A highlighted file in the Pantheon desktop][5]
-
-Of course, that's just one example of many. Pantheon is filled with small features that you don't think about until you need them.
-
-The desktop is refined and attractive, with all the intuitive parts that have disappeared from many other desktops. In many ways, it has taken the best of the good ideas of many different interfaces and refrained from implementing the excesses.
-
-![Pantheon desktop on Elementary OS][6]
-
-### Customizing the Pantheon desktop
-
-The Pantheon desktop represents a pretty clear vision of how a computer ought to be operated. The "problem" with this kind of design (outside of open source, at least) is that one person's preference may not be another person's efficiency.
-
-But this is open source. Things can be changed, and whatever can't be changed can be discarded for a different option. Pantheon is definitely a desktop for a specific set of users, but even those of us with our own expectations of how a desktop ought to work might find Pantheon refreshingly more flexible than it first appears. There are overrides for many built-in designs, and when you can't adjust something to your liking, you can easily choose an alternative application. The theme engine ensures that your replacement application looks integrated with the rest of your desktop, and the usual Linux system buses ensure that all of your chosen applications communicate with one another as expected.
-
-![Which one is the guest?][7]
-
-As compromises go, this one does a lot to meet you halfway.
-
-### A welcome addition
-
-Etymology aside, this desktop truly is an answer to the prayers of many Linux users. Whether it's your style or not, the Pantheon desktop is an important and welcome addition to the Linux user experience. Try it for yourself and see if it's the good news you've been waiting for.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/12/pantheon-linux-desktop
-
-作者：[Seth Kenlon][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/seth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb (A person programming)
-[2]: https://elementary.io/
-[3]: http://elementary.io
-[4]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
-[5]: https://opensource.com/sites/default/files/uploads/advent-pantheon-highlight.jpg (A highlighted file in the Pantheon desktop)
-[6]: https://opensource.com/sites/default/files/uploads/advent-pantheon.jpg (Pantheon desktop on Elementary OS)
-[7]: https://opensource.com/sites/default/files/uploads/advent-pantheon-pcmanfm.jpg (Which one is the guest?)
diff --git a/sources/tech/20191204 --acid -words- Handle Chromium - Firefox sessions with org-mode.md b/sources/tech/20191204 --acid -words- Handle Chromium - Firefox sessions with org-mode.md
new file mode 100644
index 0000000000..7b71e21ff3
--- /dev/null
+++ b/sources/tech/20191204 --acid -words- Handle Chromium - Firefox sessions with org-mode.md
@@ -0,0 +1,145 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lujun9972)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (#:acid 'words: Handle Chromium & Firefox sessions with org-mode)
+[#]: via: (https://acidwords.com/posts/2019-12-04-handle-chromium-and-firefox-sessions-with-org-mode.html)
+[#]: author: (Sanel Z https://acidwords.com/)
+
+Handle Chromium & Firefox sessions with org-mode
+======
+
+I was big fan of [Session Manager][1], small addon for Chrome and Chromium that will save all open tabs, assign the name to session and, when is needed, restore it.
+
+Very useful, especially if you are like me, switching between multiple "mind sessions" during the day - research, development or maybe news reading. Or simply, you'd like to remember workflow (and tabs) you had few days ago.
+
+After I decided to ditch all extensions from Chromium except [uBlock Origin][2], it was time to look for alternative. My main goal was it to be browser agnostic and session links had to be stored in text file, so I can enjoy all the goodies of plain text file. What would be better for that than good old [org-mode][3] ;)
+
+Long time ago I found this trick: [Get the currently open tabs in Google Chrome via the command line][4] and with some elisp sugar and coffee, here is the code:
+
+```
+(require 'cl-lib)
+
+(defun save-chromium-session ()
+ "Reads chromium current session and generate org-mode heading with items."
+ (interactive)
+ (save-excursion
+ (let* ((cmd "strings ~/'.config/chromium/Default/Current Session' | 'grep' -E '^https?://' | sort | uniq")
+ (ret (shell-command-to-string cmd)))
+ (insert
+ (concat
+ "* "
+ (format-time-string "[%Y-%m-%d %H:%M:%S]")
+ "\n"
+ (mapconcat 'identity
+ (cl-reduce (lambda (lst x)
+ (if (and x (not (string= "" x)))
+ (cons (concat " - " x) lst)
+ lst))
+ (split-string ret "\n")
+ :initial-value (list))
+ "\n"))))))
+
+(defun restore-chromium-session ()
+ "Restore session, by openning each link in list with (browse-url).
+Make sure to put cursor on date heading that contains list of urls."
+ (interactive)
+ (save-excursion
+ (beginning-of-line)
+ (when (looking-at "^\\*")
+ (forward-line 1)
+ (while (looking-at "^[ ]+-[ ]+\\(http.?+\\)$")
+ (let* ((ln (thing-at-point 'line t))
+ (ln (replace-regexp-in-string "^[ ]+-[ ]+" "" ln))
+ (ln (replace-regexp-in-string "\n" "" ln)))
+ (browse-url ln))
+ (forward-line 1)))))
+```
+
+So, how does it work?
+
+Evaluate above code, open new org-mode file and call `M-x save-chromium-session`. It will create something like this:
+
+```
+* [2019-12-04 12:14:02]
+ - https://www.reddit.com/r/emacs/comments/...
+ - https://www.reddit.com/r/Clojure
+ - https://news.ycombinator.com
+```
+
+or whatever urls are running in Chromium instance. To restore it back, put cursor on desired date and run `M-x restore-chromium-session`. All tabs should be back.
+
+Here is how I use it, with randomly generated data for the purpose of this text:
+
+```
+#+TITLE: Browser sessions
+
+* [2019-12-01 23:15:00]...
+* [2019-12-02 18:10:20]...
+* [2019-12-03 19:00:12]
+ - https://www.reddit.com/r/emacs/comments/...
+ - https://www.reddit.com/r/Clojure
+ - https://news.ycombinator.com
+
+* [2019-12-04 12:14:02]
+ - https://www.reddit.com/r/emacs/comments/...
+ - https://www.reddit.com/r/Clojure
+ - https://news.ycombinator.com
+```
+
+Note that hack for reading Chromium session isn't perfect: `strings` will read whatever looks like string and url from binary database and sometimes that will yield small artifacts in urls. But, you can easily edit those and keep session file lean and clean.
+
+To actually open tabs, elisp code will use [browse-url][5] and it can be further customized to run Chromium, Firefox or any other browser with `browse-url-browser-function` variable. Make sure to read documentation for this variable.
+
+Don't forget to put session file in git, mercurial or svn and enjoy the fact that you will never loose your session history again :)
+
+### What about Firefox?
+
+If you are using Firefox (recent versions) and would like to pull session urls, here is how to do it.
+
+First, download and compile [lz4json][6], small tool that will decompress Mozilla lz4json format, where Firefox stores session data. Session data (at the time of writing this post) is stored in `$HOME/.mozilla/firefox//sessionstore-backups/recovery.jsonlz4`.
+
+If Firefox is not running, `recovery.jsonlz4` will not be present, but use `previous.jsonlz4` instead.
+
+To extract urls, try this in terminal:
+
+```
+$ lz4jsoncat recovery.jsonlz4 | grep -oP '"(http.+?)"' | sed 's/"//g' | sort | uniq
+```
+
+and update `save-chromium-session` with:
+
+```
+(defun save-chromium-session ()
+ "Reads chromium current session and converts it to org-mode chunk."
+ (interactive)
+ (save-excursion
+ (let* ((path "~/.mozilla/firefox//sessionstore-backups/recovery.jsonlz4")
+ (cmd (concat "lz4jsoncat " path " | grep -oP '\"(http.+?)\"' | sed 's/\"//g' | sort | uniq"))
+ (ret (shell-command-to-string cmd)))
+...
+;; rest of the code is unchanged
+```
+
+Updating documentation strings, function name and any further refactoring is left for exercise.
+
+--------------------------------------------------------------------------------
+
+via: https://acidwords.com/posts/2019-12-04-handle-chromium-and-firefox-sessions-with-org-mode.html
+
+作者：[Sanel Z][a]
+选题：[lujun9972][b]
+译者：[lujun9972](https://github.com/lujun9972)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://acidwords.com/
+[b]: https://github.com/lujun9972
+[1]: https://chrome.google.com/webstore/detail/session-manager/mghenlmbmjcpehccoangkdpagbcbkdpc?hl=en-US
+[2]: https://chrome.google.com/webstore/detail/ublock-origin/cjpalhdlnbpafiamejdnhcphjbkeiagm?hl=en
+[3]: https://orgmode.org/
+[4]: https://superuser.com/a/1310873
+[5]: https://www.gnu.org/software/emacs/manual/html_node/emacs/Browse_002dURL.html
+[6]: https://github.com/andikleen/lz4json
diff --git a/sources/tech/20191204 Fedora Desktops - Memory Footprints.md b/sources/tech/20191204 Fedora Desktops - Memory Footprints.md
deleted file mode 100644
index f9a3ea0f3b..0000000000
--- a/sources/tech/20191204 Fedora Desktops - Memory Footprints.md
+++ /dev/null
@@ -1,82 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: ( )
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Fedora Desktops – Memory Footprints)
-[#]: via: (https://fedoramagazine.org/fedora-desktops-memory-footprints/)
-[#]: author: (Troy Dawson https://fedoramagazine.org/author/tdawson/)
-
-Fedora Desktops – Memory Footprints
-======
-
-![][1]
-
-There are over 40 desktops in Fedora. Each desktop has it’s own strengths and weaknesses. Usually picking a desktop is a very personal preference based on features, looks, and other qualities. Sometimes, what you pick for a desktop is limited by hardware constraints.
-
-This article is to help people compare Fedora desktops based on the desktop baseline memory. To narrow the scope, we are only looking at the desktops that have an official Fedora Live image.
-
-### Installation and Setup
-
-Each of the desktops was installed on it’s own KVM virtual machine. Each virtual machine had 1 CPU, 4GB of memory, 15 GB virtio solid state disk, and everything else that comes standard on RHEL 8.0 kvm.
-
-The images for installation were the standard Fedora 31 Live images. For GNOME, that image was the Fedora Workstation. For the other desktops, the corresponding Spin was used. Sugar On A Stick (SOAS) was not tested because it does not install easily onto a local drive.
-
-The virtual machine booted into the Live CD. “Install to Hard Disk” was selected. During the install, only the defaults were used. A root user, and a regular users were created. After installation and reboot, the Live image was verified to not be in the virtual CDROM.
-
-The settings for each desktop was not touched. They each ran whatever settings came default from the Live CD installation. Each desktop was logged into via the regular user. A terminal was opened. Using sudo each machine ran “dnf -y update”. After update, in that sudo terminal, each machine ran “/sbin/shutdown -h now” to shut down.
-
-### Testing
-
-Each machine was started up. The desktop was logged into via the regular user. Three of the desktop terminals were opened. xterm was never used, it was always the terminal for that desktop, such as konsole.
-
-In one terminal, top was started and M pressed, showing the processes sorted by memory. In another terminal, a simple while loop showed “free -m” every 30 seconds. The third terminal was idle.
-
-I then waited 5 minutes. This allowed any startup services to finish. I recorded the final free result, as well as the final top three memory consumers from top.
-
-### Results
-
- * Cinnamon
- * 624 MB Memory used
- * cinnamon 4.8% / Xorg 2.2% / dnfdragora 1.8%
- * GNOME
- * 612 MB Memory used
- * gnome-shell 6.9% / gnome-software 1.8% / ibus-x11 1.5%
- * KDE
- * 733 MB Memory used
- * plasmashell 6.2% / kwin_x11 3.6% / akonadi_mailfil 2.9%
- * LXDE
- * 318 MB Memory used
- * Xorg 1.9% / nm-applet 1.8% / dnfdragora 1.8%
- * LXQt
- * 391 MB Memory used
- * lxqt-panel 2.2% / pcmanfm-qt 2.1% / Xorg 2.1%
- * MATE
- * 465 MB Memory used
- * Xorg 2.5% / dnfdragora 1.8% / caja 1.5%
- * XFCE
- * 448 MB Memory used
- * Xorg 2.3% / xfwm4 2.0% / dnfdragora 1.8%
-
-
-
-### Conclusion
-
-I will let the numbers speak for themselves.
-
-Remember that these numbers are from a default Live install. If you remove, or add services and features, your memory usage will change. But this is a good baseline to look at if you are determining your desktop based on memory consumption.
-
---------------------------------------------------------------------------------
-
-via: https://fedoramagazine.org/fedora-desktops-memory-footprints/
-
-作者：[Troy Dawson][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://fedoramagazine.org/author/tdawson/
-[b]: https://github.com/lujun9972
-[1]: https://fedoramagazine.org/wp-content/uploads/2019/11/desktop-memory-footprint-816x346.jpg
diff --git a/sources/tech/20191205 Add jumping to your Python platformer game.md b/sources/tech/20191205 Add jumping to your Python platformer game.md
new file mode 100644
index 0000000000..9d64001082
--- /dev/null
+++ b/sources/tech/20191205 Add jumping to your Python platformer game.md
@@ -0,0 +1,512 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Add jumping to your Python platformer game)
+[#]: via: (https://opensource.com/article/19/12/jumping-python-platformer-game)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Add jumping to your Python platformer game
+======
+Learn how to fight gravity with jumping in this installment on
+programming video games with Python's Pygame module.
+![Arcade games][1]
+
+In the [previous article][2] in this series, you simulated gravity, but now you need to give your player a way to fight against gravity by jumping.
+
+A jump is a temporary reprieve from gravity. For a few moments, you jump _up_ instead of falling down, the way gravity is pulling you. But once you hit the peak of your jump, gravity kicks in again and pulls you back down to earth.
+
+In code, this translates to variables. First, you must establish variables for the player sprite so that Python can track whether or not the sprite is jumping. Once the player sprite is jumping, then gravity is applied to the player sprite again, pulling it back down to the nearest object.
+
+### Setting jump state variables
+
+You must add two new variables to your Player class:
+
+ * One to track whether your player is jumping or not, determined by whether or not your player sprite is standing on solid ground
+ * One to bring the player back down to the ground
+
+
+
+Add these variables to your **Player** class. In the following code, the lines above the comment are for context, so just add the final two lines:
+
+
+```
+ self.movex = 0
+ self.movey = 0
+ self.frame = 0
+ self.health = 10
+ # gravity variables here
+ self.collide_delta = 0
+ self.jump_delta = 6
+```
+
+The first variable (**collide_delta**) is set to 0 because, in its natural state, the player sprite is not in a mid-jump. The other variable (**jump_delta**) is set to 6 to prevent the sprite from bouncing (actually, jumping) when it first lands in the game world. When you've finished this article's examples, try setting it to 0 to see what happens.
+
+### Colliding mid-jump
+
+If you jump on a trampoline, your jumps are pretty impressive. But what would happen if you jumped into a wall? (Don't try it to find out!) Your jump, no matter how impressively it started, would end very quickly when you collide with something much larger and much more solid than you.
+
+To mimic this in your video game, you must set the **self.collide_delta** variable to 0 whenever your player sprite collides with something, like the ground. If **self.collide_delta** is anything other than 0, then your player is jumping, and your player can't jump when it hits a wall or the ground.
+
+In the **update** function of your **Player** class, modify the ground collision block to look like this:
+
+
+```
+ ground_hit_list = pygame.sprite.spritecollide(self, ground_list, False)
+ for g in ground_hit_list:
+ self.movey = 0
+ self.rect.y = worldy-ty-ty
+ self.collide_delta = 0 # stop jumping
+ if self.rect.y > g.rect.y:
+ self.health -=1
+ print(self.health)
+```
+
+This code block checks for collisions happening between the ground sprites and the player sprite. In the event of a collision, it sets the Y-position of the player to a value equal to the height of the game window (**worldy**) minus the height of a tile minus the height of another tile (so that the player sprite appears to be standing on top of the ground and not in the middle of it). It also sets **self.collide_delta** to 0 so that the program is aware that the player is not in mid-jump. Additionally, it sets **self.movey** to 0 so that the program is aware that the player is not being pulled by gravity (it's a quirk of game physics that you don't need to continue to pull your player toward earth once the player has been grounded).
+
+The **if** statement detects whether the player has descended _below_ the level of the ground; if so, it deducts health points as a penalty. This assumes that you want your player to lose health points for falling off the world. That's not strictly necessary; it's just a common convention in platformers. More than likely, you want this event to trigger something, though, or else your real-world player will be stuck playing a game with a sprite that's fallen off the screen. An easy recovery is to set **self.rect.y** to 0 again so that when the player sprite falls off the world, it respawns at the top of the world and falls back onto solid ground.
+
+### Hitting the ground
+
+Your simulated gravity wants your player's Y-axis movement to be 0 or more. To create a jump, write code that sends your player sprite off solid ground and into the air.
+
+In the **update** function of your **Player** class, add a temporary reprieve from gravity:
+
+
+```
+ if self.collide_delta < 6 and self.jump_delta < 6:
+ self.jump_delta = 6*2
+ self.movey -= 33 # how high to jump
+ self.collide_delta += 6
+ self.jump_delta += 6
+```
+
+According to this code, a jump sends the player sprite 33 pixels into the air. It's _negative_ 33 because a lower number in Pygame means it's closer to the top of the screen.
+
+This event is conditional, though. It only happens if **self.collide_delta** is less than 6 (its default value established in the **init** function of your **Player** sprite) and if **self.jump_delta** is less than 6. This condition prevents the player from triggering another jump until it collides with a platform. In other words, it prevents mid-air jumps.
+
+You don't have to prevent mid-air jumps, or you can allow for mid-air jumps under special conditions; for instance, if a player obtains a special loot item, then you could grant it the ability to perform mid-air jumps until the next time it is hit by an enemy.
+
+When you've finished this article's examples, try setting **self.collide_delta** and **self.jump_delta** to 0 for a 100% chance to jump in mid-air.
+
+### Landing on a platform
+
+So far, you've defined an anti-gravity condition for when the player sprite hits the ground, but the game code keeps platforms and the ground in separate lists. (As with so many choices made in this article, that's not strictly necessary, and you can experiment with treating the ground as just another platform.) To enable a player sprite to stand on top of a platform, you must detect a collision between the player sprite and a platform sprite and then perform the same actions as you did for a ground collision. Place this code into your **update** function:
+
+
+```
+ plat_hit_list = pygame.sprite.spritecollide(self, plat_list, False)
+ for p in plat_hit_list:
+ self.collide_delta = 0 # stop jumping
+ self.movey = 0
+```
+
+There's one additional concern, though: platforms hang in the air, meaning the player can interact with them by approaching them from either the top or the bottom.
+
+It's up to you how you want the platforms to react to your player. It's not uncommon to block a player from accessing a platform from below. Add this code to the above code block to treat platforms as a sort of ceiling or pergola, such that the player sprite can jump onto a platform as long as it jumps higher than the platform's topside, but obstructs the player when it tries to jump from beneath:
+
+
+```
+ if self.rect.y > p.rect.y:
+ self.rect.y = p.rect.y+ty
+ else:
+ self.rect.y = p.rect.y-ty
+```
+
+The first clause of this **if** statement blocks the player from accessing a platform when the player sprite is directly under the platform. It does this by detecting that the player sprite's position is greater (in Pygame, that means lower on the screen, from top to bottom), and then sets the player sprite's new Y position to its current Y position plus the height of a tile, effectively keeping the player one tile's height away from ever passing through a platform from beneath it.
+
+The **else** clause does the opposite. If the program is running this code, then the player sprite's Y position is _not_ greater than the platforms, meaning that the player sprite is falling from the sky (either because it has been freshly spawned there or because the player has jumped). In this event, the player sprite's position is set to the position of the platform minus one tile's height (because, remember, in Pygame, lower numbers mean something is higher up on the screen). This keeps the player on top of the platform unless it jumps or walks off of it.
+
+You can experiment with other ways of dealing with sprite and platform interaction. For instance, maybe the player is assumed to be "in front" of the platforms and can seamlessly jump through them to stand on top of one. Or a platform could slow a player's leap but not block it entirely. You can even mix and match by grouping platforms into different lists.
+
+### Triggering a jump
+
+Your code now simulates all the necessary jump conditions, but it still lacks a jump trigger. Your player sprite's **self.jump_delta** is set to 6 initially, and the jump update code is triggered only when it's less than 6.
+
+To trigger a new setting for the jumping variable, create a **jump** function in your **Player** class that sets the **self.jump_delta** to less than 6, causing gravity to be temporarily reprieved by sending your player sprite 33 pixels into the air:
+
+
+```
+ def jump(self,platform_list):
+ self.jump_delta = 0
+```
+
+That's all the **jump** function requires, believe it or not. The rest happens in the **update** function, and you've already written that code.
+
+There's one last thing to do before jumping is functional in your game. If you can't think of what it is, try playing your game to see how jumping works for you.
+
+The problem is that nothing in your main loop is calling the **jump** function. You made a placeholder keypress for it early on, but right now, all the jump key does is print **jump** to the terminal.
+
+### Calling the jump function
+
+In your main loop, change the result of the Up arrow from printing a debug statement to calling the **jump** function.
+
+Notice that the **jump** function, like the **update** function, needs to know about collisions, so you have to tell it which **plat_list** to use.
+
+
+```
+ if event.key == pygame.K_UP or event.key == ord('w'):
+ player.jump(plat_list)
+```
+
+If you would rather use the Spacebar for jumping, set the key to **pygame.K_SPACE** instead of **pygame.K_UP**. Alternately, you can use both (as separate **if** statements) so that the player has a choice.
+
+Try your game now. In the next article, you'll make your world scroll.
+
+![Pygame platformer][3]
+
+Here's all the code so far:
+
+
+```
+#!/usr/bin/env python3
+# draw a world
+# add a player and player control
+# add player movement
+# add enemy and basic collision
+# add platform
+# add gravity
+# add jumping
+
+# GNU All-Permissive License
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved. This file is offered as-is,
+# without any warranty.
+
+import pygame
+import sys
+import os
+
+'''
+Objects
+'''
+
+class Platform(pygame.sprite.Sprite):
+ # x location, y location, img width, img height, img file
+ def __init__(self,xloc,yloc,imgw,imgh,img):
+ pygame.sprite.Sprite.__init__(self)
+ self.image = pygame.image.load(os.path.join('images',img)).convert()
+ self.image.convert_alpha()
+ self.rect = self.image.get_rect()
+ self.rect.y = yloc
+ self.rect.x = xloc
+
+class Player(pygame.sprite.Sprite):
+ '''
+ Spawn a player
+ '''
+ def __init__(self):
+ pygame.sprite.Sprite.__init__(self)
+ self.movex = 0
+ self.movey = 0
+ self.frame = 0
+ self.health = 10
+ self.collide_delta = 0
+ self.jump_delta = 6
+ self.score = 1
+ self.images = []
+ for i in range(1,9):
+ img = pygame.image.load(os.path.join('images','hero' + str(i) + '.png')).convert()
+ img.convert_alpha()
+ img.set_colorkey(ALPHA)
+ self.images.append(img)
+ self.image = self.images[0]
+ self.rect = self.image.get_rect()
+
+ def jump(self,platform_list):
+ self.jump_delta = 0
+
+ def gravity(self):
+ self.movey += 3.2 # how fast player falls
+
+ if self.rect.y > worldy and self.movey >= 0:
+ self.movey = 0
+ self.rect.y = worldy-ty
+
+ def control(self,x,y):
+ '''
+ control player movement
+ '''
+ self.movex += x
+ self.movey += y
+
+ def update(self):
+ '''
+ Update sprite position
+ '''
+
+ self.rect.x = self.rect.x + self.movex
+ self.rect.y = self.rect.y + self.movey
+
+ # moving left
+ if self.movex < 0:
+ self.frame += 1
+ if self.frame > ani*3:
+ self.frame = 0
+ self.image = self.images[self.frame//ani]
+
+ # moving right
+ if self.movex > 0:
+ self.frame += 1
+ if self.frame > ani*3:
+ self.frame = 0
+ self.image = self.images[(self.frame//ani)+4]
+
+ # collisions
+ enemy_hit_list = pygame.sprite.spritecollide(self, enemy_list, False)
+ for enemy in enemy_hit_list:
+ self.health -= 1
+ #print(self.health)
+
+ plat_hit_list = pygame.sprite.spritecollide(self, plat_list, False)
+ for p in plat_hit_list:
+ self.collide_delta = 0 # stop jumping
+ self.movey = 0
+ if self.rect.y > p.rect.y:
+ self.rect.y = p.rect.y+ty
+ else:
+ self.rect.y = p.rect.y-ty
+
+ ground_hit_list = pygame.sprite.spritecollide(self, ground_list, False)
+ for g in ground_hit_list:
+ self.movey = 0
+ self.rect.y = worldy-ty-ty
+ self.collide_delta = 0 # stop jumping
+ if self.rect.y > g.rect.y:
+ self.health -=1
+ print(self.health)
+
+ if self.collide_delta < 6 and self.jump_delta < 6:
+ self.jump_delta = 6*2
+ self.movey -= 33 # how high to jump
+ self.collide_delta += 6
+ self.jump_delta += 6
+
+class Enemy(pygame.sprite.Sprite):
+ '''
+ Spawn an enemy
+ '''
+ def __init__(self,x,y,img):
+ pygame.sprite.Sprite.__init__(self)
+ self.image = pygame.image.load(os.path.join('images',img))
+ self.movey = 0
+ #self.image.convert_alpha()
+ #self.image.set_colorkey(ALPHA)
+ self.rect = self.image.get_rect()
+ self.rect.x = x
+ self.rect.y = y
+ self.counter = 0
+
+
+ def move(self):
+ '''
+ enemy movement
+ '''
+ distance = 80
+ speed = 8
+
+ self.movey += 3.2
+
+ if self.counter >= 0 and self.counter <= distance:
+ self.rect.x += speed
+ elif self.counter >= distance and self.counter <= distance*2:
+ self.rect.x -= speed
+ else:
+ self.counter = 0
+
+ self.counter += 1
+
+ if not self.rect.y >= worldy-ty-ty:
+ self.rect.y += self.movey
+
+ plat_hit_list = pygame.sprite.spritecollide(self, plat_list, False)
+ for p in plat_hit_list:
+ self.movey = 0
+ if self.rect.y > p.rect.y:
+ self.rect.y = p.rect.y+ty
+ else:
+ self.rect.y = p.rect.y-ty
+
+ ground_hit_list = pygame.sprite.spritecollide(self, ground_list, False)
+ for g in ground_hit_list:
+ self.rect.y = worldy-ty-ty
+
+
+class Level():
+ def bad(lvl,eloc):
+ if lvl == 1:
+ enemy = Enemy(eloc[0],eloc[1],'yeti.png') # spawn enemy
+ enemy_list = pygame.sprite.Group() # create enemy group
+ enemy_list.add(enemy) # add enemy to group
+
+ if lvl == 2:
+ print("Level " + str(lvl) )
+
+ return enemy_list
+
+ def loot(lvl,lloc):
+ print(lvl)
+
+ def ground(lvl,gloc,tx,ty):
+ ground_list = pygame.sprite.Group()
+ i=0
+ if lvl == 1:
+ while i < len(gloc):
+ ground = Platform(gloc[i],worldy-ty,tx,ty,'ground.png')
+ ground_list.add(ground)
+ i=i+1
+
+ if lvl == 2:
+ print("Level " + str(lvl) )
+
+ return ground_list
+
+ def platform(lvl,tx,ty):
+ plat_list = pygame.sprite.Group()
+ ploc = []
+ i=0
+ if lvl == 1:
+ ploc.append((0,worldy-ty-128,3))
+ ploc.append((300,worldy-ty-256,3))
+ ploc.append((500,worldy-ty-128,4))
+
+ while i < len(ploc):
+ j=0
+ while j <= ploc[i][2]:
+ plat = Platform((ploc[i][0]+(j*tx)),ploc[i][1],tx,ty,'ground.png')
+ plat_list.add(plat)
+ j=j+1
+ print('run' + str(i) + str(ploc[i]))
+ i=i+1
+
+ if lvl == 2:
+ print("Level " + str(lvl) )
+
+ return plat_list
+
+'''
+Setup
+'''
+worldx = 960
+worldy = 720
+
+fps = 40 # frame rate
+ani = 4 # animation cycles
+clock = pygame.time.Clock()
+pygame.init()
+main = True
+
+BLUE = (25,25,200)
+BLACK = (23,23,23 )
+WHITE = (254,254,254)
+ALPHA = (0,255,0)
+
+world = pygame.display.set_mode([worldx,worldy])
+backdrop = pygame.image.load(os.path.join('images','stage.png')).convert()
+backdropbox = world.get_rect()
+player = Player() # spawn player
+player.rect.x = 0
+player.rect.y = 0
+player_list = pygame.sprite.Group()
+player_list.add(player)
+steps = 10 # how fast to move
+jump = -24
+
+eloc = []
+eloc = [200,20]
+gloc = []
+#gloc = [0,630,64,630,128,630,192,630,256,630,320,630,384,630]
+tx = 64 #tile size
+ty = 64 #tile size
+
+i=0
+while i <= (worldx/tx)+tx:
+ gloc.append(i*tx)
+ i=i+1
+
+enemy_list = Level.bad( 1, eloc )
+ground_list = Level.ground( 1,gloc,tx,ty )
+plat_list = Level.platform( 1,tx,ty )
+
+'''
+Main loop
+'''
+while main == True:
+ for event in pygame.event.get():
+ if event.type == pygame.QUIT:
+ pygame.quit(); sys.exit()
+ main = False
+
+ if event.type == pygame.KEYDOWN:
+ if event.key == pygame.K_LEFT or event.key == ord('a'):
+ print("LEFT")
+ player.control(-steps,0)
+ if event.key == pygame.K_RIGHT or event.key == ord('d'):
+ print("RIGHT")
+ player.control(steps,0)
+ if event.key == pygame.K_UP or event.key == ord('w'):
+ print('jump')
+
+ if event.type == pygame.KEYUP:
+ if event.key == pygame.K_LEFT or event.key == ord('a'):
+ player.control(steps,0)
+ if event.key == pygame.K_RIGHT or event.key == ord('d'):
+ player.control(-steps,0)
+ if event.key == pygame.K_UP or event.key == ord('w'):
+ player.jump(plat_list)
+
+ if event.key == ord('q'):
+ pygame.quit()
+ sys.exit()
+ main = False
+
+# world.fill(BLACK)
+ world.blit(backdrop, backdropbox)
+ player.gravity() # check gravity
+ player.update()
+ player_list.draw(world) #refresh player position
+ enemy_list.draw(world) # refresh enemies
+ ground_list.draw(world) # refresh enemies
+ plat_list.draw(world) # refresh platforms
+ for e in enemy_list:
+ e.move()
+ pygame.display.flip()
+ clock.tick(fps)
+```
+
+This is the 7th installment in an ongoing series about creating video games in [Python 3][4] using the [Pygame][5] module. Previous articles are:
+
+ * [Learn how to program in Python by building a simple dice game][6]
+ * [Build a game framework with Python using the Pygame module][7]
+ * [How to add a player to your Python game][8]
+ * [Using Pygame to move your game character around][9]
+ * [What's a hero without a villain? How to add one to your Python game][10]
+ * [Simulate gravity in your Python game][2]
+
+
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/jumping-python-platformer-game
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/arcade_game_gaming.jpg?itok=84Rjk_32 (Arcade games)
+[2]: https://opensource.com/article/19/11/simulate-gravity-python
+[3]: https://opensource.com/sites/default/files/uploads/pygame-jump.jpg (Pygame platformer)
+[4]: https://www.python.org/
+[5]: https://www.pygame.org/
+[6]: https://opensource.com/article/17/10/python-101
+[7]: https://opensource.com/article/17/12/game-framework-python
+[8]: https://opensource.com/article/17/12/game-python-add-a-player
+[9]: https://opensource.com/article/17/12/game-python-moving-player
+[10]: https://opensource.com/article/18/5/pygame-enemy
diff --git a/sources/tech/20191205 Challenge- find Twitter memes with suffix arrays.md b/sources/tech/20191205 Challenge- find Twitter memes with suffix arrays.md
new file mode 100644
index 0000000000..c767c9f1ed
--- /dev/null
+++ b/sources/tech/20191205 Challenge- find Twitter memes with suffix arrays.md
@@ -0,0 +1,220 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Challenge: find Twitter memes with suffix arrays)
+[#]: via: (https://jvns.ca/blog/twitter-memes-challenge/)
+[#]: author: (Julia Evans https://jvns.ca/)
+
+Challenge: find Twitter memes with suffix arrays
+======
+
+This challenge is a mix of data analysis and using fun algorithms! It’s the second challenge in a a short series of programming challenge I’m writing with Julian. (the [first one was to write a tiny fun window manager][1])
+
+Twitter has a lot of memes. For example, if you search Twitter for [Flight attendant: is there a doctor on this flight?][2], you’ll find a bunch of tweets making jokes like this:
+
+```
+Flight Attendant: is there a doctor on board?
+Parent: *nudging* That should've been you
+Me: Not now, this is serious
+Parent: Not asking for a hacker to help, are they?
+Me: AAAAAAAA\x00\xd0X?\xfc\x7fBBBBj\x0bX\x99Rfh-p\x89\xe1Rjhh/bash/bin\x89\xe3RQS\x89\xe1\xcd\x80
+Parent:~#
+```
+
+or if you search [as a kpop fan][3] there are thousands of these:
+
+```
+me as a kpop fan
+
+- kpop fan age: 10 years
+- first group ever stan: super junior
+- current ult groups: iKON, X1, Day6
+- number of albums: >20
+- concerts attended: 6
+- lightsticks owned: 2
+```
+
+So! Suppose you have a million tweets from the last 2 days. How do you find the jokes / quizzes / memes people are playing with on Twitter?
+
+### Challenge: find the twitter memes in 1 million tweets
+
+This is a pretty open ended challenge and you can do it any way you want. Here’s a [SQLite database with 1.2 million tweets][4], collected from the [twitter streaming api][5] over 2 days. It’s 250MB (70MB compressed), it only has English tweets. It excludes retweets and many tweets that are generated by bots.
+
+The challenge: find at least 5 Twitter memes using that dataset.
+
+### memes as common substrings
+
+The idea here is that memes are substrings like “me as a kpop fan” that many different people are using. The tricky thing is that you don’t really know how long those substrings will be, and maybe you’re interested in phrases of different lengths.
+
+You can probably do this challenge without using anything fancy (with a hashmap of phrases or something) but I think it’s a nice opportunity to play with a fun data structure: suffix arrays! So let’s talk about what those are.
+
+### suffix arrays: sort all suffixes
+
+Suffix arrays sort all suffixes of a string. For example, here’s the suffix array for “plantain” which has the suffixes plantain, lantain, antain, ntain, tain, ain, in, n.
+
+```
+ain
+antain
+in
+lantain
+n
+ntain
+plantain
+tain
+```
+
+Representing this as a list of strings would be very inefficient (quadratic space), so instead we replace each suffix with the index of its first character in the original string – `[5,2,6,1,7,3,0,4]`.
+
+```
+5 (ain)
+2 (antain)
+6 (in)
+1 (lantain)
+7 (n)
+3 (ntain)
+0 (plantain)
+4 (tain)
+```
+
+Here’s a real example of what a suffix array of 1 million tweets concatenated looks like. This is an excerpt from the middle of the suffix array, with some of the suffixes that start with `A little`.
+
+```
+...
+ A little distracted for a bit ...what do i do w my life hon.........
+ A little exercise I did this afternoon. #comics #art #clip.........
+ A little extra Christmas Cash on me! Good Luck to everyone!.........
+ A little girl in Savannah, Ga., appears to be the 38th huma.........
+ A little heavy on the smut t… https://t.co/nvoxE7SNjTI wa.........
+ A little in state battle tonight. #nova vs #penn. two very .........
+ A little kiss...” one more time I’m going to vomit. #TT.........
+ A little late catching up on last nights @GoodDoctorABC. On.........
+ A little less bling never hurt anyone! Next project...🎄 .........
+ A little more intensity to augment their talent and a coupl.........
+ A little more time, because I have never lived really - Os.........
+ A little mor… https://t.co/kcq3zf9jgeWe love MX ❤️<9F>.........
+ A little over 50k! Can We Guess How Much Is In Your Account.........
+ A little ray of joy & light in the midst of these very .........
+ A little refreshment… https://t.co/HgX8PmYwPIThank you @L.........
+ A little respect goes a long way. .........
+ A little salt in d country's troubled legal system“Grant................
+ A little snow & people lose all common senseromantic st...............
+ A little sun for the soul @realfreewebcams https://t.co/3CB...............
+ A little sunkissed moment for y’all. ...............
+ ....
+```
+
+Again, this is actually represented by a bunch of integer indexes into a concatenated string of all the tweets, like `[18238223, 1921812, ...]` so it’s a LOT more memory efficient than actually repeating all those strings.
+
+### suffix arrays let you find common substrings!
+
+So what does this have to do with Twitter memes? Well, we can basically
+
+ 1. concatenate all tweets into a big string
+ 2. make a suffix array of that string
+ 3. iterate through the suffix array and notice when you see a lot of repeated substrings, like here:
+
+
+
+```
+me as a kpop fan ✨kpop fan age: 15 y/o ✨first group ever stan: blackpink ✨current ult groups: btxt ✨number of albu… https://t.co/24diHX9sLm
+me as a kpop fan ⭐k-pop fan age: 12 y/o ⭐first group ever stan: bts ⭐current ult gps: bts and txt ⭐number of albu… https://t.co/8R95roQXoE
+me as a kpop fan ⭐k-pop fan age: 14 y/o ⭐first group ever stan: girls generation ⭐current ult gp: txt ⭐number of a… https://t.co/010hLuJscF
+me as a kpop fan ⭐k-pop fan age: 14-16 y/o ⭐first group ever stan: bts ⭐current ult gps: bts txt ⭐number of albums… https://t.co/0fDcxZGRrh
+me as a kpop fan ⭐k-pop fan age: 15 y/o ⭐first group ever stan: blackpink ⭐current ult gps: txt ⭐number of albums… https://t.co/d8zZL83TvV
+me as a kpop fan 🌸 k-pop fan age: 12 years old 🌸 first group ever stan: bts 🌸 current ult gps: bts & wanna one 🌸 n… https://t.co/22R1nJpwNX
+me as a kpop fan 🌸k-pop fan age: 10 🌸first group ever stan: 2pm 🌸current ult gps: skz,got7,itzy,twice, 🌸number of… https://t.co/mAluaP2yxH
+me as a kpop fan 🌸k-pop fan age: 11 yo 🌸first group ever stan: beast 🌸current ult gps: ateez 🌸number of albums: 1… https://t.co/qxtFHG9HDg
+me as a kpop fan 🌸k-pop fan age: 11 🌸first group ever stan: bts 🌸current ult gps: bts and ateez 🌸number of albums:… https://t.co/mKXlkrBBtC
+me as a kpop fan 🌸k-pop fan age: 13 (now im 19) 🌸first group ever stan: snsd 🌸current ult gps: nct day6 aoa mamam… https://t.co/8XyQ3r5hwz
+me as a kpop fan 🌸k-pop fan age: 13 years 🌸first group ever stan: 2pm,suju,bigbang 🌸current ult gps: bts,tbz,ateez… https://t.co/Zs1nQQz6Lt
+me as a kpop fan 🌸k-pop fan age: 14 (2005) 🌸first group ever stan: super junior 🌸current ult gps: exo, gfriend, rv… https://t.co/vgmhe2vFMY
+me as a kpop fan 🌸k-pop fan age: 14 y/o 🌸first group ever stan: nct dream 🌸current ult gps: svt and,,*insert stan… https://t.co/I38Ui69PvL
+me as a kpop fan 🌸k-pop fan age: 15 y/o 🌸first group ever stan: 5sos 🌸current ult gps: bts and 5sos also some ggs… https://t.co/61ZmRkzmdl
+me as a kpop fan 🌸k-pop fan age: 15 y/o 🌸first group ever stan: bts 🌸current ult gps: SVT, GOT7, Day6 🌸number of… https://t.co/16SWb3mSPg
+me as a kpop fan 🌸k-pop fan age: 18 🌸first group ever stan: suju & soshi 🌸current ult gps: snsd & izone 🌸number of… https://t.co/SmSBFqJnGk
+me as a kpop fan 🌸k-pop fan age: 19 y/o marupok 🌸first group ever stan: APINK 🌸current ult gps: SEVENTEEN 🌸number… https://t.co/StYjxr6uq9
+me as a kpop fan 🌸k-pop fan age: 19 🌸first group ever stan: SuJu 🌸current ult gps: SuJu, SF9, SKZ, VIXX, ONEUS, NO… https://t.co/2o2DulCY5b
+```
+
+### suffix arrays also enable really fast search
+
+As an aside, the reason I got interested in suffix arrays in the first place was actually not for finding Twitter memes at all but for search.
+
+I’ve spent a lot of time using Nelson Elhage’s [livegrep][6] at work to search code. It creates a suffix array using the divsufsort library. He has a blog post [Regular Expression Search with Suffix Arrays][7] where he talks about some of the implementation details.
+
+The reason suffix arrays work for fast search is basically that if you’re looking for the string `A little`, you can do a binary search over the suffix array to find every instance of `A little` in your dataset. Binary searches are extremely fast so every search is guaranteed to run very quickly (in less than a microsecond I believe). What livegrep does is more complicated than that because it does a regular expression search, but that’s the idea to start.
+
+There’s another blog post [How to use suffix arrays to combat common limitations of full-text search][8] applying suffix arrays to searching through a patent database. In that example, like with code search, the patent officers want to search patents for exact strings.
+
+### How do you make a suffix array?
+
+You can use an existing suffix array library, for example [index/suffixarray in Go][9], which is what I used, or [divsufsort][10]. There are [Python bindings for divsufsort][11].
+
+If you’re more excited about the data structures/algorithms aspect of suffix arrays you can also implement a suffix array-building algorithm yourself! I did not do this but you can see an implementation of [qsufsort here in Go][12]. That implementation links to a paper. There are lots of algorithms for constructing suffix arrays –`sais` and `divsufsort` are a couple of others.
+
+### 5 or so hours, 100 lines of Go
+
+As always with these challenges, I did this one to make sure that it’s both doable in a reasonable amount of time and fun for at least one person (me).
+
+I did this one in about 5 hours and 100 lines of Go using the suffixarray implementation in the Go standard library, with a bit of bash shell scripting to postprocess the results. This is a messy data analysis challenge – as an example of a messy thing, Spotify released their end-of-2019 results while I was building the dataset and so there are a lot of tweets generated by the Spotify app.
+
+My results ended up looking something like this:
+
+```
+5 an Aries and that’s why I gotta
+5 an Aries and that’s why I am so
+5 an Aquarius and that’s why I
+5 AM SO PROUD OF YOU
+5 am not a fan of
+5 am I the only one who
+5 am going to have to
+```
+
+Then I sifted through them pretty manually to find the Twitter memes.
+
+### suffix arrays are used in bioinformatics
+
+This “find twitter memes using suffix arrays” approach is a silly thing but it does have some relationship to reality – DNA sequences are basically really long strings, and biologists need to find patterns in them, and they sometimes use suffix arrays to do it.
+
+I looked up [packages in Debian that use libdivsufsort][13] and I found [infernal][14]:
+
+> Infernal (“INFERence of RNA ALignment”) is for searching DNA sequence databases for RNA structure and sequence similarities. It is an implementation of a special case of profile stochastic context-free grammars called covariance models (CMs). A CM is like a sequence profile, but it scores a combination of sequence consensus and RNA secondary structure consensus, so in many cases, it is more capable of identifying RNA homologs that conserve their secondary structure more than their primary sequence.
+
+### email me the twitter memes you find if you do this!
+
+If you do this exercise, I’d love it if you emailed me ([[email protected]][15]) with the twitter memes you found and/or your code! I found about 8 but I’m sure there are more.
+
+I’ll publish any solutions I get (unless you don’t want me to publish your solution – just let me know!).
+
+Thanks to Julian for discussing suffix arrays and suffix trees and trigram indexes with me at length, and to Kamal who had the idea of using suffix arrays to find Twitter memes.
+
+--------------------------------------------------------------------------------
+
+via: https://jvns.ca/blog/twitter-memes-challenge/
+
+作者：[Julia Evans][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://jvns.ca/
+[b]: https://github.com/lujun9972
+[1]: https://jvns.ca/blog/2019/11/25/challenge--make-a-bouncy-window-manager/
+[2]: https://twitter.com/search?q=%22attendant%3A%20is%20there%20a%20doctor%20on%20%22&src=typed_query&f=live
+[3]: https://twitter.com/search?q=%22as%20a%20kpop%20fan%22&src=typed_query
+[4]: https://www.dropbox.com/s/5xnaf1mbdr1424p/twitter.db.gz?dl=0
+[5]: https://developer.twitter.com/en/docs/tutorials/consuming-streaming-data
+[6]: https://livegrep.com/search/linux
+[7]: https://blog.nelhage.com/2015/02/regular-expression-search-with-suffix-arrays/
+[8]: https://blog.griddynamics.com/using-suffix-arrays-to-fix-limitations-of-full-text-search/
+[9]: https://golang.org/pkg/index/suffixarray/
+[10]: https://github.com/y-256/libdivsufsort
+[11]: https://github.com/debatem1/pydivsufsort
+[12]: https://github.com/golang/go/blob/release-branch.go1.12/src/index/suffixarray/qsufsort.go
+[13]: https://codesearch.debian.net/search?q=divsufsort
+[14]: http://eddylab.org/infernal/
+[15]: https://jvns.ca/cdn-cgi/l/email-protection
diff --git a/sources/tech/20191206 A beginner-s guide to using Vagrant.md b/sources/tech/20191206 A beginner-s guide to using Vagrant.md
new file mode 100644
index 0000000000..a96389215c
--- /dev/null
+++ b/sources/tech/20191206 A beginner-s guide to using Vagrant.md
@@ -0,0 +1,219 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (A beginner's guide to using Vagrant)
+[#]: via: (https://opensource.com/article/19/12/beginner-vagrant)
+[#]: author: (Jessica Repka https://opensource.com/users/jrepka)
+
+A beginner's guide to using Vagrant
+======
+This easy "hello world" tutorial makes it easy to start using Vagrant
+for virtual machine management.
+![A person programming][1]
+
+Vagrant [describes itself][2] as "a tool for building and managing virtual machine environments in a single workflow. With an easy-to-use workflow and focus on automation, Vagrant lowers development environment setup time, increases production parity, and makes the 'works on my machine' excuse a relic of the past."
+
+Vagrant works with a standard format for documenting an environment, called a Vagrantfile. [According to Vagrant's website][3]:
+
+> "The primary function of the Vagrantfile is to describe the type of machine required for a project, and how to configure and provision these machines. Vagrantfiles are called Vagrantfiles because the actual literal filename for the file is **Vagrantfile** (casing does not matter unless your file system is running in a strict case sensitive mode)."
+
+Vagrant is essentially a wrapper to allow for repeatable virtual machine management, but it does not run VMs itself. This tutorial will use [VirtualBox][4] as that environment manager, though Hyper-V and Docker also work by default. Check out Vagrant's documentation to [learn how to use a different provider][5] for this tutorial.
+
+### Build a Vagrantfile
+
+This tutorial works through an example application for a simple Hello World page inside a Ruby on Rails (Rails for short) web app. Before you begin, install the following (if you haven't already):
+
+ * [Vagrant][6]
+ * [VirtualBox][7]
+ * [Ruby on Rails][8]
+ * An editing environment, like [Atom][9] or [Notepad++][10]
+
+
+
+If you're on Fedora and prefer using the command line, there is an [excellent Fedora tutorial][11], and there's a similarly helpful tutorial for [Windows using Chocolatey][12]. After everything is installed, open your terminal and create a new directory to work in. You can put your directory wherever you like; I prefer to use a folder under my user account:
+
+
+```
+$ mkdir -p ~/Development/Rails_app
+$ cd ~/Development/Rails_app
+$ vagrant init
+
+A `Vagrantfile` has been placed in this directory. You are now
+ready to `vagrant up` your first virtual environment! Please read
+the comments in the Vagrantfile as well as documentation on
+`vagrantup.com` for more information on using Vagrant.
+```
+
+This creates a Vagrantfile with the default configuration information written in Ruby syntax. Look at line 15:
+
+
+```
+`config.vm.box = "base"`
+```
+
+This indicates that Vagrant will use a default operating system image it hosts called **base**, which you don't have yet. Confirm that by running **box list**:
+
+
+```
+$ vagrant box list
+
+There are no installed boxes! Use `vagrant box add` to add some.
+```
+
+If you try to start your environment using the **up** command, it will fail, because Vagrant expects an OS called **base** to exist locally. Switch to the most commonly used environment, **bento/ubuntu-16.04**, then try to spin up your environment. Change the **config.vm.box** line in your Vagrantfile to:
+
+
+```
+`config.vm.box = "centos/7"`
+```
+
+And now you can run the most satisfying command in virtual machine history:
+
+
+```
+$ vagrant up
+Bringing machine 'default' up with 'libvirt' provider...
+==> default: Box 'centos/7' could not be found. Attempting to find and install...
+ default: Box Provider: libvirt
+ default: Box Version: >= 0
+==> default: Loading metadata for box 'centos/7'
+ default: URL:
+==> default: Adding box 'centos/7' (v1905.1) for provider: libvirt
+ default: Downloading:
+ default: Download redirected to host: cloud.centos.org
+...
+```
+
+Here is why this is so nice. This tutorial sets up a small website, but if you had a larger website and needed to check whether the frontend looks right, your playbook file and copy-over files would allow you to see your changes. If you have small applications you want to test quickly—without doing an entire Docker image build or logging into a server—this local testing is good for quick checks and repairs. If you're working within hardware, this will make it easy to see if the application will work within your operating system, and it allows you to know which dependencies you need. In the end, it makes for easier deployment and faster testing than doing a from-scratch continuous integration and deployment (CI/CD) to a test server, and it provides quicker access and more control.
+
+The reason this is so cool can be explained in one simple sentence: You now have local automation. It also allows you to gather a larger breadth of knowledge behind [Ansible][13] and headless server deployments.
+
+### Verify Vagrant worked correctly
+
+One way to determine whether this finished properly is seeing a bunch of green text and the words **rails server -h** for startup options. This means the web app has started and is running.
+
+![Verifying with the vagrant status command][14]
+
+But you want to use **vagrant global-status** as well as **vagrant status**.
+
+![Verifying with the vagrant global-status command][15]
+
+The **vagrant status** command checks the machine states that originate in the current directory. So, if you have a VM up and running, it will show as up and running. If it is broken in any way, it will display a message with an error and some logs when you run **vagrant up**. If some machines are down, they will also show as not running or shut down.
+
+However, the **vagrant global-status** command can give the status of multiple environments created in Vagrant. So, if you split the environments for different VM types or storage types, this command gives you an option to see everything in all the environments you've created.
+
+### Customize the Vagrant configuration
+
+The machine settings have multiple [config.vm][16] options. This tutorial will use the networking option to allow port forwarding. Port forwarding allows you to access a network port in our virtual environment as if it was a local port via a special local network. This means traffic is allowed to see the one thing you allow on this server; in this case, it's a tiny frontend webpage.
+
+The main reason this matters is for security. Limiting traffic can prevent bad actors and traffic overflow. The way this is built, you can't log into this server unless you configure it as such. This also means no one else can SSH in or see anything except the one little frontend webpage.
+
+Before moving on, remove the VM so you can start over by running [**vagrant destroy**][17]:
+
+
+```
+$ vagrant destroy
+ default: Are you sure you want to destroy the 'default' VM? [y/N] y
+==> default: Removing domain...
+```
+
+To include port forwarding, add this in the next config line:
+
+
+```
+ Vagrant.configure("2") do |config|
+ config.vm.box = "bento/ubuntu-16.04"
+ config.vm.network "forwarded_port", guest: 3000, host: 9090
+ end
+```
+
+Save the file and run:
+
+
+```
+`vagrant up`
+```
+
+You now have a VM that forwards port **3000** out to the open world as **9090**. You should now be able to go to **127.0.0.1:9090** on your web browser and see nothing but a plain white page.
+
+Run **vagrant destroy** again to remove the VM so you can start over.
+
+### Provision Vagrant with Ansible and scripts
+
+While base boxes offer a good starting point, it's common to customize a VM during the provisioning process, and you can use multiple provisioning tactics. To follow along, [download the playbook and script][18].
+
+This example uses Ansible to set up a basic install of the Ruby on Rails web framework. Then, it adds an extra shell script to configure the web app's welcome page to say: _Hello World, Sorry for the Delay_. (The purpose of this message is because this build takes a long time and people may become frustrated by the delay.)
+
+The following Vagrantfile reflects Ansible and a playbook running locally on my machine, so it will differ from yours. You can read about [using Ansible with Vagrant][19] in Vagrant's docs.
+
+
+```
+Vagrant.configure("2") do |config|
+ config.vm.box = "bento/ubuntu-16.04"
+ config.vm.network "forwarded_port", guest: 3000, host: 9090
+ ####### Provision #######
+ config.vm.provision "ansible_local" do |ansible|
+ ansible.playbook = "prov/playbook.yml"
+ ansible.verbose = true
+ config.vm.provision "shell", path: "script.sh"
+ end
+end
+```
+
+After saving the file, run my favorite command:
+
+
+```
+`vagrant up`
+```
+
+You now have a VM up and running with Rails, and when you enter **127.0.0.1:9090** in your web browser, you see a webpage that says: _Hello World, Sorry for the Delay_.
+
+Now that you have all this background, you can try to [build your own script][20].
+
+### Final notes
+
+Vagrant is fairly easy to work with and has abundant [documentation][21] to help you along the way. It's is a great tool if you're looking to work with code in a small staging or development environment; any destruction is a non-issue because the environment itself is disposable.
+
+Want to give it a try? Take a look at my [repo][18].
+
+In this short video, Daniel Farrell tells us about Vagrant, a tool for working with Virtual...
+
+Learn how Vagrant and Ansible can be used to provision virtual machines for web development.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/beginner-vagrant
+
+作者：[Jessica Repka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/jrepka
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb (A person programming)
+[2]: https://www.vagrantup.com/intro/index.html
+[3]: https://www.vagrantup.com/docs/vagrantfile/
+[4]: https://www.virtualbox.org/browser/vbox/trunk
+[5]: https://www.vagrantup.com/docs/providers/basic_usage.html
+[6]: https://www.vagrantup.com/docs/installation/
+[7]: https://www.virtualbox.org/wiki/Downloads
+[8]: http://installrails.com/steps/choose_os
+[9]: https://atom.io/
+[10]: https://notepad-plus-plus.org/downloads/
+[11]: https://computingforgeeks.com/how-to-install-vagrant-and-virtualbox-on-fedora/
+[12]: https://codingbee.net/vagrant/vagrant-installing-vagrant-on-windows
+[13]: https://www.ansible.com/
+[14]: https://opensource.com/sites/default/files/uploads/vagrant1_vagrant-status.png (Verifying with the vagrant status command)
+[15]: https://opensource.com/sites/default/files/uploads/vagrant2_vagrant-global-status.png (Verifying with the vagrant global-status command)
+[16]: https://www.vagrantup.com/docs/vagrantfile/machine_settings.html
+[17]: https://www.vagrantup.com/docs/cli/destroy.html
+[18]: https://github.com/Alynder/vagrant_adwx
+[19]: https://www.vagrantup.com/docs/provisioning/ansible.html
+[20]: https://www.bogotobogo.com/RubyOnRails/RubyOnRails_HelloWorld_Rails.php
+[21]: https://www.vagrantup.com/docs/index.html
diff --git a/sources/tech/20191208 8 Best Open Source Accounting Software.md b/sources/tech/20191208 8 Best Open Source Accounting Software.md
new file mode 100644
index 0000000000..3639504902
--- /dev/null
+++ b/sources/tech/20191208 8 Best Open Source Accounting Software.md
@@ -0,0 +1,199 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (8 Best Open Source Accounting Software)
+[#]: via: (https://itsfoss.com/open-source-accounting-software/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+8 Best Open Source Accounting Software
+======
+
+Accounting software is a necessity when it comes to managing billings, debts, stocks, invoices and any other kind of financial transactions. You might require something for your personal finances or perhaps for enterprise-focused accounting software. No matter what, it is important to consider open source solutions available (especially being Linux enthusiasts).
+
+So, in this article, I list out some of the best open source accounting software that I think would come in handy for you. At the end of the list, feel free to suggest your favorite ones in the comments.
+
+### Best Open Source Accounting Software
+
+**Note:** _The list is in no particular order of ranking._
+
+#### 1\. Skrooge
+
+![][1]
+
+Key Highlights:
+
+ * Personal finances manager
+ * Tailored for Plasma Desktop but compatible with others too
+ * Cross-platform (Windows, Linux, and macOS)
+
+
+
+Skrooge is one of the most useful personal finances manager by KDE. It is originally tailored for the Plasma Desktop but other desktop environments are compatible.
+
+Supports most of the basic features (reporting, budgeting, etc.) and allows you to work on some pretty big data sets.
+
+[Skrooge][2]
+
+#### 2\. Akaunting
+
+![][3]
+
+Key Highlights:
+
+ * Online accounting software
+ * Completely free and open source
+ * Client portal
+ * Invoicing
+ * Expense tracking
+ * Reporting
+ * Cashflow
+
+
+
+Akaunting is an interesting online accounting software that’s available for free. Yes, surprisingly, there’s no hidden subscription charges or additional upgrade options. It is totally free. If you are looking for a FreshBooks alternative, you should give it a try.
+
+Ranging from invoicing to managing deposits and transfers. A whole lot of features. You can either utilize their hosting (again, it is free!) or host it yourself. It’s fit for both personal and enterprise needs. Try it out!
+
+[Akaunting][4]
+
+#### 3\. Apache OFBiz
+
+![][5]
+
+Key Highlights:
+
+ * ERP & CRM
+ * Developer-friendly
+ * Powerful Java Web Framework
+ * Cross-platform (Linux and macOS)
+
+
+
+We’ve already mentioned this in our list of [best open source CRM software][6]. Apache OFBiz is an impressive open source solution that incorporates an ERP system and a CRM suite for various types of requirements.
+
+It’s completely free – however, you will have to host it yourself (or just hire someone to do it). In addition to all the basic features needed for accounting software, it lets a developer extend/enhance features easily while being a Java-based web framework.
+
+[Apache OFBiz][7]
+
+#### 4\. iDempiere
+
+![][8]
+
+Key Highlights:
+
+ * Community-focused
+ * Simple and useful
+ * Cross-platform (Linux and Windows)
+
+
+
+Originally based on ADEmpiere ERP. It is a community focused accounting software maintained by an active group of people. iDempiere aims to utilize technologies like [Apache Maven][9] to provide a business suite ERP/CRM/SCM.
+
+There’s a ready-to-use Virtual machine available to download. In addition, you can utilize it on Windows or Linux.
+
+[iDempiere][10]
+
+#### 5\. Openmiracle
+
+![Openmiracle][11]
+
+Key Highlights:
+
+ * Plug-ins available
+ * Completely free
+
+
+
+Openmiracle is a quite popular open source and free accounting software. There’s no premium plans to it. So, you can utilize all the power and flexibility for free.
+
+It features all the necessary options needed in an accounting software. From setting the budget to managing the payroll, there’s a lot of things to explore.
+
+[Openmiracle][12]
+
+#### 6\. GnuCash
+
+![][13]
+
+Key Highlights:
+
+ * Cross-platform (Linux, Windows, and macOS)
+ * Fit for personal and small businesses
+
+
+
+GNUCash is a great open-source financial accounting software to manage stocks/income/expenses for small business or individuals.
+
+From reports to quick calculation features, it has a lot to offer. And, the best thing is – it is available across multiple platforms (including Linux), so that’s a plus.
+
+[GNUCash][14]
+
+#### 7\. LedgerSMB
+
+![Ledgersmb Screenshot][15]
+
+Key Highlights:
+
+ * Dead simple open source ERP
+ * Optional commercial support available
+ * Cross-platform (Windows, Linux, and macOS)
+
+
+
+A powerful yet simple open source accounting solution. It has been tailored to small and medium sized businesses. Starting from managing invoices to inventory – you also get the ability to translate (up to 45 languages supported). You can try pre-release version or just get the latest stable build to test it out yourself!
+
+[LedgerSMB][16]
+
+#### 8\. GNUKhata
+
+Key Highlights:
+
+ * GST, VAT compliant Invoices if you are based in India (tailored for Indian users)
+ * Easy to use
+ * Simple user interface
+ * Cross-platform (Windows and Linux)
+
+
+
+We already covered an article on [GNUKhata][17], if you want to dive into the details.
+
+However, it is a simple and robust accounting software that is available for free. From the looks of it, the setup is easy and anyone can get used to it. Feel free to try it out and explore.
+
+[GNUKhata][18]
+
+**Wrapping Up**
+
+These are our recommended picks for an open source accounting software. If we missed listing your favorite open-source accounting software, let us in the comments below.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/open-source-accounting-software/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/09/skrooge.jpg?ssl=1
+[2]: https://skrooge.org/
+[3]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/09/akaunting.jpg?ssl=1
+[4]: https://akaunting.com/
+[5]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/07/apache-ofbiz.jpg?ssl=1
+[6]: https://itsfoss.com/best-open-source-crm/
+[7]: https://ofbiz.apache.org/
+[8]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/09/idempiere.jpg?ssl=1
+[9]: https://en.wikipedia.org/wiki/Apache_Maven
+[10]: https://www.idempiere.org/home
+[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/09/openmiracle.jpg?ssl=1
+[12]: http://www.openmiracle.com/
+[13]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/09/gnucash-screenshot.png?ssl=1
+[14]: https://www.gnucash.org/
+[15]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/09/ledgerSMB-screenshot.jpg?ssl=1
+[16]: https://ledgersmb.org/
+[17]: https://itsfoss.com/using-gnu-khata/
+[18]: https://gnukhata.in/
diff --git a/sources/tech/20191208 Dynamically scoped variables in Go.md b/sources/tech/20191208 Dynamically scoped variables in Go.md
new file mode 100644
index 0000000000..959799f89e
--- /dev/null
+++ b/sources/tech/20191208 Dynamically scoped variables in Go.md
@@ -0,0 +1,200 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Dynamically scoped variables in Go)
+[#]: via: (https://dave.cheney.net/2019/12/08/dynamically-scoped-variables-in-go)
+[#]: author: (Dave Cheney https://dave.cheney.net/author/davecheney)
+
+Dynamically scoped variables in Go
+======
+
+This is a thought experiment in API design. It starts with the classic Go unit testing idiom:
+
+```
+func TestOpenFile(t *testing.T) {
+ f, err := os.Open("notfound")
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // ...
+}
+```
+
+What’s the problem with this code? The assertion. `if err != nil { ... }` is repetitive and in the case where multiple conditions need to be checked, somewhat error prone if the author of the test uses `t.Error` not `t.Fatal`, eg:
+
+```
+f, err := os.Open("notfound")
+if err != nil {
+ t.Error(err)
+}
+f.Close() // boom!
+```
+
+What’s the solution? DRY it up, of course, by moving the repetitive assertion logic to a helper:
+
+```
+func TestOpenFile(t *testing.T) {
+ f, err := os.Open("notfound")
+ check(t, err)
+
+ // ...
+}
+
+func check(t *testing.T, err error) {
+ if err != nil {
+ t.Helper()
+ t.Fatal(err)
+ }
+}
+```
+
+Using the `check` helper the code is a little cleaner, and clearer, _check the error_, and hopefully the indecision between `t.Error` and `t.Fatal` has been solved. The downside of abstracting the assertion to a helper function is now you need to pass a `testing.T` into _each and every invocation_. Worse, you need to pass a `*testing.T` to everything that needs to call `check`, transitively, just in case.
+
+This is ok, I guess, but I will make the observation that the `t` variable is only needed _when the assertion fails_ — and even in a testing scenario, most of the time, most of the tests pass, so that means reading, and writing, all these `t`‘s is a constant overhead for the relatively rare occasion that a test fails.
+
+What about if we did something like this instead?
+
+```
+func TestOpenFile(t *testing.T) {
+ f, err := os.Open("notfound")
+ check(err)
+
+ // ...
+}
+
+func check(err error) {
+ if err != nil {
+ panic(err.Error())
+ }
+}
+```
+
+Yeah, that’ll work, but it has a few problems
+
+```
+% go test
+--- FAIL: TestOpenFile (0.00s)
+panic: open notfound: no such file or directory [recovered]
+ panic: open notfound: no such file or directory
+
+goroutine 22 [running]:
+testing.tRunner.func1(0xc0000b4400)
+ /Users/dfc/go/src/testing/testing.go:874 +0x3a3
+panic(0x111b040, 0xc0000866f0)
+ /Users/dfc/go/src/runtime/panic.go:679 +0x1b2
+github.com/pkg/expect_test.check(...)
+ /Users/dfc/src/github.com/pkg/expect/expect_test.go:18
+github.com/pkg/expect_test.TestOpenFile(0xc0000b4400)
+ /Users/dfc/src/github.com/pkg/expect/expect_test.go:10 +0xa1
+testing.tRunner(0xc0000b4400, 0x115ac90)
+ /Users/dfc/go/src/testing/testing.go:909 +0xc9
+created by testing.(*T).Run
+ /Users/dfc/go/src/testing/testing.go:960 +0x350
+exit status 2
+```
+
+Let’s start with the good; we didn’t have to pass a `testing.T` every place we call `check`, the test fails immediately, and we get a nice message in the panic — albeit twice. But _where_ the assertion failed is hard to see. It occurred on `expect_test.go:11` but you’d be forgiven for not knowing that.
+
+So `panic` isn’t really a good solution, but there’s something in this stack trace that is — can you see it? Here’s a hint, `github.com/pkg/expect_test.TestOpenFile(0xc0000b4400)`.
+
+`TestOpenFile` has a `t` value, it was passed to it by `tRunner`, so there’s a `testing.T` in memory at address `0xc0000b4400`. What if we could get access to that `t` inside `check`? Then we could use it to call `t.Helper` and `t.Fatal`. Is that possible?
+
+### Dynamic scoping
+
+What we want is to be able to access a variable whose declaration is neither global, or local to the function, but somewhere higher in the call stack. This is called _dynamic scoping_. Go doesn’t support dynamic scoping, but it turns out, for restricted cases, we can fake it. I’ll skip to the chase:
+
+```
+// getT returns the address of the testing.T passed to testing.tRunner
+// which called the function which called getT. If testing.tRunner cannot
+// be located in the stack, say if getT is not called from the main test
+// goroutine, getT returns nil.
+func getT() *testing.T {
+ var buf [8192]byte
+ n := runtime.Stack(buf[:], false)
+ sc := bufio.NewScanner(bytes.NewReader(buf[:n]))
+ for sc.Scan() {
+ var p uintptr
+ n, _ := fmt.Sscanf(sc.Text(), "testing.tRunner(%v", &p)
+ if n != 1 {
+ continue
+ }
+ return (*testing.T)(unsafe.Pointer(p))
+ }
+ return nil
+}
+```
+
+We know that each `Test` is called by the `testing` package in its own goroutine (see the stack trace above). The `testing` package launches the test via a function called `tRunner` which takes a `*testing.T` and a `func(*testing.T)` to invoke. Thus we grab a stack trace of the current goroutine, scan through it for the line beginning with `testing.tRunner` — which can only be the `testing` package as `tRunner` is a private function — and parse the address of the first parameter, which is a pointer to a `testing.T`. With a little `unsafe` we convert the raw pointer back to a `*testing.T` and we’re done.
+
+If the search fails then it is likely that `getT` wasn’t called from a `Test`. This is actually ok because the reason we needed the `*testing.T` was to call `t.Fatal` and the testing package already requires that `t.Fatal` be called from the [main test goroutine][1].
+
+```
+import "github.com/pkg/expect"
+
+func TestOpenFile(t *testing.T) {
+ f, err := os.Open("notfound")
+ expect.Nil(err)
+
+ // ...
+}
+```
+
+Putting it all together we’ve eliminated the assertion boilerplate and possibly made the expectation of the test a little clearer to read, _after opening the file `err` is expected to be nil_.
+
+### Is this fine?
+
+At this point you should be asking, _is this fine?_ And the answer is, no, this is not fine. You should be screaming internally at this point. But it’s probably worth introspecting those feelings of revulsion.
+
+Apart from the inherent fragility of scrobbling around in a goroutine’s call stack, there are some serious design issues:
+
+ 1. The `expect.Nil`‘s behaviour now depends on _who called it_. Provided with the same arguments it may have different behaviour depending on where it appears in the call stack — this is unexpected.
+ 2. Taken to the extreme dynamic scoping effective brings into the scope of a single function all the variables passed into any function that preceded it. It is a side channel for passing data in to and out of functions that is not explicitly documented in function declaration.
+
+
+
+Ironically these are precisely the critiques I have of [`context.Context`][2]. I’ll leave it to you to decide if they are justified.
+
+### A final word
+
+This is a bad idea, no argument there. This is not a pattern you should ever use in production code. But, this isn’t production code, it’s a test, and perhaps there are different rules that apply to test code. After all, we use mocks, and stubs, and monkey patching, and type assertions, and reflection, and helper functions, and build flags, and global variables, all so we can test our code effectively. None of those, uh, _hacks_ will ever show up in the production code path, so is it really the end of the world?
+
+If you’ve read this far perhaps you’ll agree with me that as unconventional as this approach is, not having to pass a `*testing.T` into every function that could possibly need to assert something transitively, makes for clearer test code.
+
+So maybe, in this case, the ends do justify the means.
+
+* * *
+
+If you’re interested, I’ve put together a [small assertion library][3] using this pattern. _Caveat emptor_.
+
+#### Related posts:
+
+ 1. [Go, without package scoped variables][4]
+ 2. [On declaring variables][5]
+ 3. [A whirlwind tour of Go’s runtime environment variables][6]
+ 4. [You shouldn’t name your variables after their types for the same reason you wouldn’t name your pets “dog” or “cat”][7]
+
+
+
+--------------------------------------------------------------------------------
+
+via: https://dave.cheney.net/2019/12/08/dynamically-scoped-variables-in-go
+
+作者：[Dave Cheney][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://dave.cheney.net/author/davecheney
+[b]: https://github.com/lujun9972
+[1]: https://golang.org/pkg/testing/#T.FailNow
+[2]: https://dave.cheney.net/2017/01/26/context-is-for-cancelation
+[3]: https://github.com/pkg/expect
+[4]: https://dave.cheney.net/2017/06/11/go-without-package-scoped-variables (Go, without package scoped variables)
+[5]: https://dave.cheney.net/2014/05/24/on-declaring-variables (On declaring variables)
+[6]: https://dave.cheney.net/2015/11/29/a-whirlwind-tour-of-gos-runtime-environment-variables (A whirlwind tour of Go’s runtime environment variables)
+[7]: https://dave.cheney.net/2019/01/29/you-shouldnt-name-your-variables-after-their-types-for-the-same-reason-you-wouldnt-name-your-pets-dog-or-cat (You shouldn’t name your variables after their types for the same reason you wouldn’t name your pets “dog” or “cat”)
diff --git a/sources/tech/20191208 What-s your favorite terminal emulator.md b/sources/tech/20191208 What-s your favorite terminal emulator.md
new file mode 100644
index 0000000000..ff3ed8349d
--- /dev/null
+++ b/sources/tech/20191208 What-s your favorite terminal emulator.md
@@ -0,0 +1,74 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (What's your favorite terminal emulator?)
+[#]: via: (https://opensource.com/article/19/12/favorite-terminal-emulator)
+[#]: author: (Opensource.com https://opensource.com/users/admin)
+
+What's your favorite terminal emulator?
+======
+We asked our community to tell us about their experience with terminal
+emulators. Here are a few of the responses we received. Take our poll to
+weigh in on your favorite.
+![Terminal window with green text][1]
+
+Preference of a terminal emulator can say a lot about a person's workflow. Is the ability to drive mouseless a must-have? Do you like to navigate between tabs or windows? There's something to be said about how it makes you feel, too. Does it have that cool factor? Tell us about your favorite terminal emulator by taking our poll or leaving us a comment. How many have you tried?
+
+We asked our community to tell us about their experience with terminal emulators. Here are a few of the responses we received.
+
+"My favorite terminal emulator is Tilix, customized with Powerline. I love that it supports multiple terminals open in a single window." —Dan Arel
+
+"urxvt ([rxvt-unicode][2]). It's simple to configure via files, is lightweight, and readily available in most package manager repositories." —Brian Tomlinson
+
+"gnome-terminal is still my go-to even though I don't use GNOME anymore. :)" —Justin W. Flory
+
+"Terminator at this point on FC31. I just started using it but like the split screen feature and it seems light enough for me. Investigating plugins." —Marc Maxwell
+
+"I switched over to Tilix a while back and it does everything I need terminals to do. :) Multiple panes, notifications, lean and runs my tmux sessions great." —Kevin Fenzi
+
+"alacritty. It's optimized for speed, implemented in Rust and generally feature packed, but, honestly speaking, I only care about one feature: configurable inter-glyph spacing that allows me to further condense my font. I'm so-o hooked." —Alexander Sosedkin
+
+
+"I am old and grumpy: KDE Konsole. With tmux in it if session is remote." —Marcin Juszkiewicz
+
+"iTerm2 for macOS. Yes, it's open source. :-) Terminator on Linux." —Patrick Mullins
+
+ "I've been using alacritty for a year or two now, but recently I started also using cool-retro-term in fullscreen mode whenever I have to run a script that has a lot of output because it looks cool and makes me feel cool. This is important to me." —Nick Childers
+
+"I love Tilix, partly because it's good at staying out of the way (I usually just run it full screen with tmux inside), but also for the custom hotlinking support: in my terminal, text like "rhbz#1234" is a hotlink that takes me to bugzilla. Similar for LaunchPad issues, Gerrit change ids for OpenStack, etc." —Lars Kellogg-Stedman
+
+"Eterm, also presentations look best in cool-retro-term with Vintage profile." —Ivan Horvath
+
+"+1 for Tilix. It’s the best for an option for GNOME users, IMO!" —Eric Rich
+
+"urxvt. Fast. Small. Configurable. Extendable via perl plugins, which can make it mouseless." —Roman Dobosz
+
+"Konsole is the best, the only app I use from KDE project. The highlight of all search result occurrences is a killer feature which afaik does not have any other Linux terminal (glad if you prove me wrong). Best for searching compilation errors and output logs." —Jan Horak
+
+"I use Terminator in past a lot. Now I cloned the theme (dark one) in Tilix and I didn't miss a thing. Is easy to move between tabs. That's all." —Alberto Fanjul Alonso
+
+"Started my journey in using Terminator, I have since (in the past 3 years or so) completely switched over to Tilix." —Mike Harris
+
+"I use Drop Down Terminal X. It's a very simple extension for GNOME 3 that lets me have a terminal always at the stroke of a single key (F12 for me). And it also supports tabs, which is kind of all I need." —Germán Pulido
+
+"xfce4-terminal: wayland support, zoom, no borders, no title bar, no scroll bar - that's all I want from terminal emulator, for everything else I have tmux. I want my terminal emulator to use as much screen space as possible as I usually have editor (Vim) and repl side by side in tmux panes." —Martin Kourim
+
+"Fish! Don’t ask! ;-)" —Eric Schabell
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/favorite-terminal-emulator
+
+作者：[Opensource.com][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/admin
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc_terminals_0.png?itok=XwIRERsn (Terminal window with green text)
+[2]: https://opensource.com/article/19/10/why-use-rxvt-terminal
diff --git a/sources/tech/20191208 Why choose Xfce for your lightweight Linux desktop.md b/sources/tech/20191208 Why choose Xfce for your lightweight Linux desktop.md
new file mode 100644
index 0000000000..cde1d600d7
--- /dev/null
+++ b/sources/tech/20191208 Why choose Xfce for your lightweight Linux desktop.md
@@ -0,0 +1,63 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Why choose Xfce for your lightweight Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/xfce-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Why choose Xfce for your lightweight Linux desktop
+======
+This article is part of a special series of 24 days of Linux desktops.
+Looking for for a lightweight Linux distribution with plenty of
+features? The Xfce Linux desktop has been the standard for a long time.
+![Woman sitting in front of her laptop][1]
+
+The [Xfce desktop][2] has a specific, self-stated goal: to be fast on a system with low resources while being visually appealing and user-friendly. It's been the de facto choice for lightweight Linux distributions (or remixes) for years and is often cited by its fans as a desktop that provides just enough to be useful, but never so much as to be a burden.
+
+You may find Xfce included in the software repository of your Linux distribution, or you can download and install a distribution that ships Xfce as an available desktop (like the Xfce [Mageia][3] or [Fedora][4] spins or [Slackware][5]). Before you install it, be aware that, while it's lightweight, it is intended to provide a full desktop experience, so many Xfce apps are installed along with the desktop. If you're already running a different desktop, you may find yourself with redundant applications (two PDF readers, two file managers, and so on). If you just want to try the Xfce desktop, you can install an Xfce-based distribution in a virtual machine, such as [GNOME Boxes][6].
+
+### Xfce desktop tour
+
+True to the Unix philosophy, Xfce keeps its desktop modular. Many different components, such as the xfwm4 window manager, xfce4-panel, xfdesktop, Thunar, Xfconf, and so on, are bundled together to form the Xfce desktop environment. That may seem a pedantic way of defining a bunch of components that are always bundled together as a desktop, but in the case of Xfce, it's significant because these components truly are separate. You can run the Xfce panel over your Openbox or PekWM window manager, or use Xfce applets in your Fluxbox toolbar, and run Thunar as your file manager in Cinnamon or Pantheon. The possibilities are endless, but together they form the Xfce desktop.
+
+The design of the Xfce desktop is clean, direct, and true to its Unix origins. Xfce began as some desktop widgets written with the XForms framework, even before GNOME existed. It was based conceptually upon the CDE desktop, which was the ubiquitous desktop at the time. Neither CDE nor XForms were open source, but Xfce was distributed freely. Eventually, Xfce was rewritten using the open source GTK toolkit, was included in several distributions, became a popular CDE and GNOME alternative, and eventually became the dominant choice of "lightweight" distributions.
+
+Here's what it looked like on [Alan Formy-Duval's][7] desktop back in 2003:
+
+![XFCE in 2003][8]
+
+Xfce isn't necessarily a simple desktop: its application menu is in the upper-left corner (a tradition familiar to Linux users but probably foreign to newcomers), and it has a place for pinned application launchers, a system tray, virtual desktops, and a taskbar. It's a proper control panel for the GUI side of a Linux computer, with all the essential knobs and switches exposed for easy access. And it does all of that without making much of an impact on your system resources.
+
+![XFCE in 2019 on Mageia Linux][9]
+
+Significantly, Xfce uses GTK libraries to accomplish a lightweight desktop, and in doing so, it looks good, it looks familiar, and it can be themed to look really beautiful. The [Xfce screenshot forum][10] affords users the opportunity to show off their themes and configurations.
+
+### Using the Xfce desktop
+
+Xfce is an ideal desktop for a server or when you want quick access to important settings on a desktop that you rarely _look_ at. It's also ideal for Linux power users who want to adjust common settings quickly, but otherwise rarely deals with the GUI. Then again, it's a good-looking lightweight desktop, it can be themed easily, and it's got plenty of features. It may be the perfect desktop for you, no matter how you use your Linux computer. The only way to find out is to try!
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/xfce-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_women_computing_4.png?itok=VGZO8CxT (Woman sitting in front of her laptop)
+[2]: http://xfce.org
+[3]: http://mageia.org
+[4]: http://fedoraproject.org
+[5]: http://slackware.com
+[6]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[7]: https://opensource.com/users/alanfdoss
+[8]: https://opensource.com/sites/default/files/advent-xfce-2003.jpg (XFCE in 2003)
+[9]: https://opensource.com/sites/default/files/advent-xfce.jpg (XFCE on Mageia Linux in 2019)
+[10]: https://forum.xfce.org/viewtopic.php?id=12676
diff --git a/sources/tech/20191209 Use the Fluxbox Linux desktop as your window manager.md b/sources/tech/20191209 Use the Fluxbox Linux desktop as your window manager.md
new file mode 100644
index 0000000000..8c7ddcb1e5
--- /dev/null
+++ b/sources/tech/20191209 Use the Fluxbox Linux desktop as your window manager.md
@@ -0,0 +1,164 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Use the Fluxbox Linux desktop as your window manager)
+[#]: via: (https://opensource.com/article/19/12/fluxbox-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Use the Fluxbox Linux desktop as your window manager
+======
+This article is part of a special series of 24 days of Linux desktops.
+Fluxbox is very light on system resources, yet it has vital Linux
+desktop features to make your user experience easy, blazingly efficient,
+and unduly fast.
+![Text editor on a browser, in blue][1]
+
+The concept of a desktop may differ from one computer user to another. Many people see the desktop as a home base, or a comfy living room, or even a literal desktop where they place frequently used notepads, their best pens and pencils, and their favorite coffee mug. KDE, GNOME, Pantheon (and so on) provide that kind of comfort on Linux.
+
+But for some users, the desktop is just empty monitor space, a side effect of not yet having any free-floating application windows projected directly onto their retina. For these users, the desktop is a void over which they can run applications—whether big office and graphic suites, or a simple terminal window, or docked applets—to manage services. This model of operating a [POSIX][2] computer has a long history, and one branch of that family tree is the *box window managers: Blackbox, Fluxbox, and Openbox.
+
+[Fluxbox][3] is a window manager for X11 systems that's based on an older project called Blackbox. Blackbox development was waning when I discovered Linux, so I fell into Fluxbox, and I've used it ever since on at least one of my active systems. It is written in C++ and is licensed under the MIT open source license.
+
+### Installing Fluxbox
+
+You are likely to find Fluxbox included in the software repository of your Linux distribution, but you can also find it on [Fluxbox.org][4]. If you're already running a different desktop, it's safe to install Fluxbox on the same system because Fluxbox doesn't predetermine any configuration or accompanying applications.
+
+After installing Fluxbox, log out of your current desktop session so you can log into your new one. By default, your session manager (KDM, GDM, LightDM, or XDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+To override the desktop with GDM:
+
+![Select your desktop session in GDM][5]
+
+Or with KDM:
+
+![Select your desktop session with KDM][6]
+
+### Configuring the Fluxbox desktop
+
+When you first log in, the screen is mostly empty because all Fluxbox provides are panels (for a taskbar, system tray, and so on) and window decoration for application windows.
+
+![Default Fluxbox configuration on CentOS 7][7]
+
+If your distribution delivers a plain Fluxbox desktop, you can set a background for your desktop using the **feh** command (you may need to install it from your distribution's repository). This command has a few options for setting the background, including **\--bg-fill** to fill the screen with your wallpaper of choice, **\--bg-scale** to scale it to fit, and so on.
+
+
+```
+`$ feh --bg-fill ~/photo/oamaru/leaf-spiral.jpg`
+```
+
+![Fluxbox with a theme applied][8]
+
+By default, Fluxbox auto-generates a menu, available with a right-click anywhere on the desktop, that gives you access to applications. Depending on your distribution, this menu may be very minimal, or it may list all the launchers in your **/usr/share/applications** directory.
+
+Fluxbox configuration is set in text files, and those text files are contained in the **$HOME/.fluxbox** directory. You can:
+
+ * Set keyboard shortcuts in **keys**
+ * Set startup services and applications in **startup**
+ * Set desktop preferences (such as the number of workspaces, locations of panels, and so on) in **init**
+ * Set menu items in **menu**
+
+
+
+The text configuration files are easy to reverse-engineer, but you also can (and should) read the Fluxbox [documentation][9].
+
+For example, this is my typical menu (or at least the basic structure of it):
+
+
+```
+# to use your own menu, copy this to ~/.fluxbox/menu, then edit
+# ~/.fluxbox/init and change the session.menuFile path to ~/.fluxbox/menu
+
+[begin] (fluxkbox)
+ [submenu] (apps) {}
+ [submenu] (txt) {}
+ [exec] (Emacs 23 (text\\)) { x-terminal-emulator -T "Emacs (text)" -e /usr/bin/emacs -nw} <>
+ [exec] (Emacs (X11\\)) {/usr/bin/emacs} <>
+ [exec] (LibreOffice) {/usr/bin/libreoffice}
+ [end]
+ [submenu] (code) {}
+ [exec] (qtCreator) {/usr/bin/qtcreator}
+ [exec] (eclipse) {/usr/bin/eclipse}
+ [end]
+ [submenu] (graphics) {}
+ [exec] (ksnapshot) {/usr/bin/ksnapshot}
+ [exec] (gimp) {/usr/bin/gimp}
+ [exec] (blender) {/usr/bin/blender}
+ [end]
+ [submenu] (files) {}
+ [exec] (dolphin) {/usr/bin/dolphin}
+ [exec] (konqueror) { /usr/bin/kfmclient openURL $HOME }
+ [end]
+ [submenu] (network) {}
+ [exec] (firefox) {/usr/bin/firefox}
+ [exec] (konqueror) {/usr/bin/konqueror}
+ [end]
+ [end]
+## change window manager or work env
+[submenu] (environments) {}
+ [restart] (flux) {/usr/bin/startfluxbox}
+ [restart] (ratpoison) {/usr/bin/ratpoison}
+ [exec] (openIndiana) {/home/kenlon/qemu/startSolaris.sh}
+[end]
+
+[config] (config)
+ [submenu] (styles) {}
+ [stylesdir] (/usr/share/fluxbox/styles)
+ [stylesdir] (~/.fluxbox/styles)
+ [end]
+[workspaces] (workspaces)
+[reconfig] (reconfigure)
+[restart] (restart)
+[exit] (exeunt)
+[end]
+```
+
+The menu also provides a few preference settings, such as the ability to pick a theme and restart or log out from your Fluxbox session.
+
+I launch most applications using keyboard shortcuts, which are entered into the **keys** configuration file. Here are some examples (the **Mod4** key is the Super key, which I use to designate global shortcuts):
+
+
+```
+# open apps
+Mod4 t :Exec konsole
+Mod4 k :Exec konqueror
+Mod4 z :Exec fbrun
+Mod4 e :Exec emacs
+Mod4 f :Exec firefox
+Mod4 x :Exec urxvt
+Mod4 d :Exec dolphin
+Mod4 q :Exec xscreensaver-command -activate
+Mod4 3 :Exec ksnapshot
+```
+
+Between these shortcuts and an open terminal, I have little use for a mouse during most of my workday, so there's no wasted time switching from one controller to another. And because Fluxbox stays well out of the way, there's little distraction.
+
+### Why you should use Fluxbox
+
+Fluxbox is very light on system resources, yet it has vital features to make your user experience easy, blazingly efficient, and unduly fast. It's simple to customize, and it allows you to define your own workflow. You don't have to use Fluxbox's panels, because there are other excellent panels out there. You can even middle-click and drag two separate application windows into one another so that they become one window, each in its own tab.
+
+The possibilities are endless, so try the steady simplicity that is Fluxbox on your Linux box today!
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/fluxbox-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/browser_blue_text_editor_web.png?itok=lcf-m6N7 (Text editor on a browser, in blue)
+[2]: https://opensource.com/article/19/7/what-posix-richard-stallman-explains
+[3]: http://fluxbox.org
+[4]: http://fluxbox.org/download/
+[5]: https://opensource.com/sites/default/files/advent-gdm_0.jpg (Select your desktop session in GDM)
+[6]: https://opensource.com/sites/default/files/advent-kdm.jpg (Select your desktop session with KDM)
+[7]: https://opensource.com/sites/default/files/advent-fluxbox-default.jpg (Default Fluxbox configuration on CentOS 7)
+[8]: https://opensource.com/sites/default/files/advent-fluxbox-green.jpg (Fluxbox with a theme applied)
+[9]: http://fluxbox.org/features/
diff --git a/sources/tech/20191210 App Highlight- Open Source Video Transcoder Handbrake.md b/sources/tech/20191210 App Highlight- Open Source Video Transcoder Handbrake.md
new file mode 100644
index 0000000000..d6e239c3eb
--- /dev/null
+++ b/sources/tech/20191210 App Highlight- Open Source Video Transcoder Handbrake.md
@@ -0,0 +1,151 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (App Highlight: Open Source Video Transcoder Handbrake)
+[#]: via: (https://itsfoss.com/handbrake/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+App Highlight: Open Source Video Transcoder Handbrake
+======
+
+_**Brief: HandBrake is a free and open-source video conversion tool that is quite useful. Let’s see what are its main features and how to use them for converting videos from one format to another.**_
+
+### HandBrake: An Open Source Video Transcoder
+
+![][1]
+
+[HandBrake][2] is a quite useful tool which helps you to convert a video from one format to some of the widely supported codecs (**.mp4/.m4v/.mkv/.webm**)
+
+It can support any video format and help you convert it. In addition to that, you have several features on board to customize the video attributes while converting.
+
+If you are looking for a [Format Factory alternative][3], this is your best bet.
+
+I shall highlight the key features to help you know more.
+
+![HandBrake][4]
+
+### Features of HandBrake
+
+When you start using the video transcoder, you will find a lot of tiny features for video conversion. However, here, I’ll highlight the important things you need to know about HandBrake:
+
+#### Video Conversion Presets
+
+![HandBrake Presets][5]
+
+Suppose you want to convert a full HD video to play on a mobile which was originally tailored for desktop viewing, what do you do?
+
+Would you test various dimensions and convert them repeatedly to get the perfect mobile port? Or, would you rather prefer to have pre-defined settings for such conversions?
+
+If you opt for a preset, you just have to select the target device (or type of device) from the list of available presets.
+
+It even features presets for PS4 Pro (4K) and Discord. So, you can expect a big list of presets available.
+
+#### Input Sources Support
+
+Unless the file has some sort of copy protection, HandBrake can help you convert it. You will have no problems whatsoever even if you have an Ultra HD Blu-ray disc as the source with no copyright protection.
+
+All the available video encoding formats should work fine as an input source file.
+
+#### Basic Video Manipulation
+
+![HandBrake Screenshot][6]
+
+In addition to the ability of video conversion, it also lets you tweak the video to suit your requirements.
+
+You can change the dimensions, crop it, add a filter, change the frame rate settings, and a lot more things.
+
+If that wasn’t enough, you also get the ability to add subtitles and chapter markers.
+
+#### Live Video Preview
+
+This may not be a big deal to have – but I haven’t seen any video converter tool featuring video previews while being able to convert/tweak the video. It could come in handy for someone specific.
+
+### Installing HandBrake on Ubuntu and other Linux distributions
+
+HandBrake is a cross-platform application and you can install it on all different platforms like Linux, macOS and Windows. Just head over to heir website and download it from there.
+
+[Download HandBrake for any platform][7]
+
+On It’s FOSS, our focus is on Linux so I am going to show the steps to install it on Linux.
+
+**Installing HandBrake on Ubuntu**
+
+HandBrake is available in the [universe repository in Ubuntu][8]. If you have it enabled, you should find it in the software center. Just search for the name and install it from there.
+
+![HandBrake in Ubuntu Software Center][9]
+
+You can also use terminal for installing HandBrake with apt or [apt-get command][10]:
+
+```
+sudo apt-get install handbrake
+```
+
+However, the software center might feature the older version. If you want to install the latest version of HandBrake on Ubuntu and other Ubuntu-based distributions, you can [use its official PPA][11]. It’s better to uninstall any existing version of HandBrake beforehand.
+
+```
+sudo apt remove handbrake
+sudo add-apt-repository ppa:stebbins/handbrake-releases
+sudo apt update
+sudo apt install handbrake-gtk
+```
+
+You can [learn more about using PPA here][12]. It will help you to [remove PPA][13], if you ever need to uninstall HandBrake installed via the PPA.
+
+If you want to install the CLI version of Handbrake, simply use this command:
+
+```
+sudo apt install handbrake-cli
+```
+
+Quite honestly, HandBrake should be used as a GUI application. If you want command line, you can always [use ffmpeg][14] that is more powerful and HandBrake uses it underneath anyways.
+
+**Installing HandBrake on other Linux distributions**
+
+HandBrake is one of the [popular Linux software][15] and it should be available in the official repositories of almost all Linux distributions.
+
+Just use the software center or package manager of your distribution to install HandBrake.
+
+But again, your distribution might not have the latest version of HandBrale. So, if you want the latest version installed, you can try installing the [Flatpak package][16] available. If you are not sure how to use Flatpak, refer to our guide on [using Flatpak on Linux][17].
+
+[HandBrake][2]
+
+**Wrapping Up**
+
+A free and open-source video conversion tool that gets the job done. I’m quite satisfied with it personally.
+
+If you use HandBrake extensively, mention at least one feature that you like the most about it.
+
+If you use some other application for converting video formats, do share it with us in the comments.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/handbrake/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/12/handbrake_software_logo.png?ssl=1
+[2]: https://handbrake.fr/
+[3]: https://itsfoss.com/format-factory-alternative-linux/
+[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/handbrake.png?ssl=1
+[5]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/handbrake-presets.png?ssl=1
+[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/11/handbrake-screenshot.png?ssl=1
+[7]: https://handbrake.fr/downloads.php
+[8]: https://itsfoss.com/ubuntu-repositories/
+[9]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/handbrake_ubuntu_software_center.png?ssl=1
+[10]: https://itsfoss.com/apt-get-linux-guide/
+[11]: https://launchpad.net/~stebbins/+archive/ubuntu/handbrake-releases
+[12]: https://itsfoss.com/ppa-guide/
+[13]: https://itsfoss.com/how-to-remove-or-delete-ppas-quick-tip/
+[14]: https://itsfoss.com/ffmpeg/
+[15]: https://itsfoss.com/essential-linux-applications/
+[16]: https://flathub.org/apps/details/fr.handbrake.ghb
+[17]: https://itsfoss.com/flatpak-guide/
diff --git a/sources/tech/20191210 Lessons learned from programming in Go.md b/sources/tech/20191210 Lessons learned from programming in Go.md
new file mode 100644
index 0000000000..1702d36c47
--- /dev/null
+++ b/sources/tech/20191210 Lessons learned from programming in Go.md
@@ -0,0 +1,334 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Lessons learned from programming in Go)
+[#]: via: (https://opensource.com/article/19/12/go-common-pitfalls)
+[#]: author: (Eduardo Ferreira https://opensource.com/users/edufgf)
+
+Lessons learned from programming in Go
+======
+Prevent future concurrent processing headaches by learning how to
+address these common pitfalls.
+![Goland gopher illustration][1]
+
+When you are working with complex distributed systems, you will likely come across the need for concurrent processing. At [Mode.net][2], we deal daily with real-time, fast and resilient software. Building a global private network that dynamically routes packets at the millisecond scale wouldn’t be possible without a highly concurrent system. This dynamic routing is based on the state of the network and, while there are many parameters to consider here, our focus is on link [metrics][3]. In our context, link metrics can be anything related to the status or current properties of a network link (e.g.: link latency).
+
+### Concurrent probing for link metrics
+
+[H.A.L.O.][4] (Hop-by-Hop Adaptive Link-State Optimal Routing), our dynamic routing algorithm relies partially on link metrics to compute its routing table. Those metrics are collected by an independent component that sits on each [PoP][5] (Point of Presence). PoPs are machines that represent a single routing entity in our networks, connected by links and spread around multiple locations shaping our network. This component probes neighboring machines using network packets, and those neighbors will bounce back the initial probe. Link latency values can be derived from the received probes. Because each PoP has more than one neighbor, the nature of such a task is intrinsically concurrent: we need to measure latency for each neighboring link in real-time. We can’t afford sequential processing; each probe must be processed as soon as possible in order to compute this metric.
+
+![latency computation graph][6]
+
+### Sequence numbers and resets: A reordering situation
+
+Our probing component exchanges packets and relies on sequence numbers for packet processing. This aims to avoid processing of packet duplication or out-of-order packets. Our first implementation relied on a special sequence number 0 to reset sequence numbers. Such a number was only used during initialization of a component. The main problem was that we were considering an increasing sequence number value that always started at 0. After the component restarts, packet reordering could happen, and a packet could easily replace the sequence number with the value that was being used before the reset. This meant that the following packets would be ignored until it reaches the sequence number that was in use just before the reset.
+
+### UDP handshake and finite state machine
+
+The problem here was proper agreement of a sequence number after a component restarts. There are a few ways to handle this and, after discussing our options, we chose to implement a 3-way handshake protocol with a clear definition of states. This handshake establishes sessions over links during initialization. This guarantees that nodes are communicating over the same session and using the appropriate sequence number for it.
+
+To properly implement this, we have to define a finite state machine with clear states and transitions. This allows us to properly manage all corner cases for the handshake formation.
+
+![finite state machine diagram][7]
+
+Session IDs are generated by the handshake initiator. A full exchange sequence is as follows:
+
+ 1. The sender sends out a **SYN (ID)*** *packet.
+ 2. The receiver stores the received **ID** and sends a **SYN-ACK (ID)**.
+ 3. The sender receives the **SYN-ACK (ID) *_and sends out an **ACK (ID)**._ *It also starts sending packets starting with sequence number 0.
+ 4. The receiver checks the last received **ID*** _and accepts the **ACK (ID)**_ *if the ID matches. It also starts accepting packets with sequence number 0.
+
+
+
+### Handling state timeouts
+
+Basically, at each state, you need to handle, at most, three types of events: link events, packet events, and timeout events. And those events show up concurrently, so here you have to handle concurrency properly.
+
+ * Link events are either link up or link down updates. This can either initiate a link session or break an existing session.
+ * Packet events are control packets **(SYN/SYN-ACK/ACK)** or just probe responses.
+ * Timeout events are the ones triggered after a scheduled timeout expires for the current session state.
+
+
+
+The main challenge here is how to handle concurrent timeout expiration and other events. And this is where one can easily fall into the traps of deadlocks and race conditions.
+
+### A first approach
+
+The language used for this project is [Golang][8]. It does provide native synchronization mechanisms such as native channels and locks and is able to spin lightweight threads for concurrent processing.
+
+![gophers hacking together][9]
+
+gophers hacking together
+
+You can start first by designing a structure that represents our **Session** and **Timeout Handlers**.
+
+
+```
+type Session struct {
+ State SessionState
+ Id SessionId
+ RemoteIp string
+}
+
+type TimeoutHandler struct {
+ callback func(Session)
+ session Session
+ duration int
+ timer *timer.Timer
+}
+```
+
+**Session** identifies the connection session, with the session ID, neighboring link IP, and the current session state.
+
+**TimeoutHandler** holds the callback function, the session for which it should run, the duration, and a pointer to the scheduled timer.
+
+There is a global map that will store, per neighboring link session, the scheduled timeout handler.
+
+
+```
+`SessionTimeout map[Session]*TimeoutHandler`
+```
+
+Registering and canceling a timeout is achieved by the following methods:
+
+
+```
+// schedules the timeout callback function.
+func (timeout* TimeoutHandler) Register() {
+ timeout.timer = time.AfterFunc(time.Duration(timeout.duration) * time.Second, func() {
+ timeout.callback(timeout.session)
+ })
+}
+
+func (timeout* TimeoutHandler) Cancel() {
+ if timeout.timer == nil {
+ return
+ }
+ timeout.timer.Stop()
+}
+```
+
+For the timeouts creation and storage, you can use a method like the following:
+
+
+```
+func CreateTimeoutHandler(callback func(Session), session Session, duration int) *TimeoutHandler {
+ if sessionTimeout[session] == nil {
+ sessionTimeout[session] := new(TimeoutHandler)
+ }
+
+ timeout = sessionTimeout[session]
+ timeout.session = session
+ timeout.callback = callback
+ timeout.duration = duration
+ return timeout
+}
+```
+
+Once the timeout handler is created and registered, it runs the callback after _duration_ seconds have elapsed. However, some events will require you to reschedule a timeout handler (as it happens at **SYN** state — every 3 seconds).
+
+For that, you can have the callback rescheduling a new timeout:
+
+
+```
+func synCallback(session Session) {
+ sendSynPacket(session)
+
+ // reschedules the same callback.
+ newTimeout := NewTimeoutHandler(synCallback, session, SYN_TIMEOUT_DURATION)
+ newTimeout.Register()
+
+ sessionTimeout[state] = newTimeout
+}
+```
+
+This callback reschedules itself in a new timeout handler and updates the global **sessionTimeout** map.
+
+### **Data race and references**
+
+Your solution is ready. One simple test is to check that a timeout callback is executed after the timer has expired. To do this, register a timeout, sleep for its duration, and then check whether the callback actions were done. After the test is executed, it is a good idea to cancel the scheduled timeout (as it reschedules), so it won’t have side effects between tests.
+
+Surprisingly, this simple test found a bug in the solution. Canceling timeouts using the cancel method was just not doing its job. The following order of events would cause a data race condition:
+
+ 1. You have one scheduled timeout handler.
+ 2. Thread 1:
+a) You receive a control packet, and you now want to cancel the registered timeout and move on to the next session state. (e.g. received a **SYN-ACK** **after you sent a **SYN**).
+b) You call **timeout.Cancel()**, which calls a **timer.Stop()**. (Note that a Golang timer stop doesn’t prevent an already expired timer from running.)
+ 3. Thread 2:
+a) Right before that cancel call, the timer has expired, and the callback was about to execute.
+b) The callback is executed, it schedules a new timeout and updates the global map.
+ 4. Thread 1:
+a) Transitions to a new session state and registers a new timeout, updating the global map.
+
+
+
+Both threads were updating the timeout map concurrently. The end result is that you failed to cancel the registered timeout, and then you also lost the reference to the rescheduled timeout done by thread 2. This results in a handler that keeps executing and rescheduling for a while, doing unwanted behavior.
+
+### When locking is not enough
+
+Using locks also doesn’t fix the issue completely. If you add locks before processing any event and before executing a callback, it still doesn’t prevent an expired callback to run:
+
+
+```
+func (timeout* TimeoutHandler) Register() {
+ timeout.timer = time.AfterFunc(time.Duration(timeout.duration) * time._Second_, func() {
+ stateLock.Lock()
+ defer stateLock.Unlock()
+
+ timeout.callback(timeout.session)
+ })
+}
+```
+
+The difference now is that the updates in the global map are synchronized, but this doesn’t prevent the callback from running after you call the **timeout.Cancel() **— This is the case if the scheduled timer expired but didn’t grab the lock yet. You should again lose reference to one of the registered timeouts.
+
+### Using cancellation channels
+
+Instead of relying on golang’s **timer.Stop()**, which doesn’t prevent an expired timer to execute, you can use cancellation channels.
+
+It is a slightly different approach. Now you won’t do a recursive re-scheduling through callbacks; instead, you register an infinite loop that waits for cancellation signals or timeout events.
+
+The new **Register()** spawns a new go thread that runs your callback after a timeout and schedules a new timeout after the previous one has been executed. A cancellation channel is returned to the caller to control when the loop should stop.
+
+
+```
+func (timeout *TimeoutHandler) Register() chan struct{} {
+ cancelChan := make(chan struct{})
+
+ go func () {
+ select {
+ case _ = <\- cancelChan:
+ return
+ case _ = <\- time.AfterFunc(time.Duration(timeout.duration) * time.Second):
+ func () {
+ stateLock.Lock()
+ defer stateLock.Unlock()
+
+ timeout.callback(timeout.session)
+ } ()
+ }
+ } ()
+
+ return cancelChan
+}
+
+func (timeout* TimeoutHandler) Cancel() {
+ if timeout.cancelChan == nil {
+ return
+ }
+ timeout.cancelChan <\- struct{}{}
+}
+```
+
+This approach gives you a cancellation channel for each timeout you register. A cancel call sends an empty struct to the channel and triggers the cancellation. However, this doesn’t resolve the previous issue; the timeout can expire right before you call cancel over the channel, and before the lock is grabbed by the timeout thread.
+
+The solution here is to check the cancellation channel inside the timeout scope after you grab the lock.
+
+
+```
+ case _ = <\- time.AfterFunc(time.Duration(timeout.duration) * time.Second):
+ func () {
+ stateLock.Lock()
+ defer stateLock.Unlock()
+
+ select {
+ case _ = <\- handler.cancelChan:
+ return
+ default:
+ timeout.callback(timeout.session)
+ }
+ } ()
+ }
+```
+
+Finally, this guarantees that the callback is only executed after you grab the lock and no cancellation was triggered.
+
+### Beware of deadlocks
+
+This solution seems to work; however, there is one hidden pitfall here: [deadlocks][10].
+
+Please read the code above again and try to find it yourself. Think of concurrent calls to any of the methods described.
+
+The last problem here is with the cancellation channel itself. We made it an unbuffered channel, which means that sending is a blocking call. Once you call cancel in a timeout handler, you only proceed once that handler is canceled. The problem here is when you have multiple calls to the same cancelation channel, where a cancel request is only consumed once. And this can easily happen if concurrent events were to cancel the same timeout handler, like a link down or control packet event. This results in a deadlock situation, possibly bringing the application to a halt.
+
+![gophers on a wire, talking][11]
+
+Is anyone listening?
+
+By Trevor Forrey. Used with permission.
+
+The solution here is to at least make the channel buffered by one, so sends are not always blocking, and also explicitly make the send non-blocking in case of concurrent calls. This guarantees the cancellation is sent once and won’t block the subsequent cancel calls.
+
+
+```
+func (timeout* TimeoutHandler) Cancel() {
+ if timeout.cancelChan == nil {
+ return
+ }
+
+ select {
+ case timeout.cancelChan <\- struct{}{}:
+ default:
+ // can’t send on the channel, someone has already requested the cancellation.
+ }
+}
+```
+
+### Conclusion
+
+You learned in practice how common mistakes can show up while working with concurrent code. Due to their non-deterministic nature, those issues can go easily undetected, even with extensive testing. Here are the three main problems we encountered in the initial implementation.
+
+#### Updating shared data without synchronization
+
+This seems like an obvious one, but it’s actually hard to spot if your concurrent updates happen in different locations. The result is data race, where multiple updates to the same data can cause update loss, due to one update overriding another. In our case, we were updating the scheduled timeout reference on the same shared map. (Interestingly, if Go detects a concurrent read/write on the same Map object, it throws a fatal error —you can try to run Go’s [data race detector][12]). This eventually results in losing a timeout reference and making it impossible to cancel that given timeout. Always remember to use locks when they are needed.
+
+![gopher assembly line][13]
+
+don’t forget to synchronize gophers’ work
+
+#### Missing condition checks
+
+Condition checks are needed in situations where you can’t rely only on the lock exclusivity. Our situation is a bit different, but the core idea is the same as [condition variables][14]. Imagine a classic situation where you have one producer and multiple consumers working with a shared queue. A producer can add one item to the queue and wake up all consumers. The wake-up call means that some data is available at the queue, and because the queue is shared, access must be synchronized through a lock. Every consumer has a chance to grab the lock; however, you still need to check if there are items in the queue. A condition check is needed because you don’t know the queue status by the time you grab the lock.
+
+In our example, the timeout handler got a ‘wake up’ call from a timer expiration, but it still needed to check if a cancel signal was sent to it before it could proceed with the callback execution.
+
+![gopher boot camp][15]
+
+condition checks might be needed if you wake up multiple gophers
+
+#### Deadlocks
+
+This happens when one thread is stuck, waiting indefinitely for a signal to wake up, but this signal will never arrive. Those can completely kill your application by halting your entire program execution.
+
+In our case, this happened due to multiple send calls to a non-buffered and blocking channel. This meant that the send call would only return after a receive is done on the same channel. Our timeout thread loop was promptly receiving signals on the cancellation channel; however, after the first signal is received, it would break off the loop and never read from that channel again. The remaining callers are stuck forever. To avoid this situation, you need to carefully think through your code, handle blocking calls with care, and guarantee that thread starvation doesn’t happen. The fix in our example was to make the cancellation calls non-blocking—we didn’t need a blocking call for our needs.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/go-common-pitfalls
+
+作者：[Eduardo Ferreira][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/edufgf
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/go-golang.png?itok=OAW9BXny (Goland gopher illustration)
+[2]: http://mode.net
+[3]: https://en.wikipedia.org/wiki/Metrics_%28networking%29
+[4]: https://people.ece.cornell.edu/atang/pub/15/HALO_ToN.pdf
+[5]: https://en.wikipedia.org/wiki/Point_of_presence
+[6]: https://opensource.com/sites/default/files/uploads/image2_0_3.png (latency computation graph)
+[7]: https://opensource.com/sites/default/files/uploads/image3_0.png (finite state machine diagram)
+[8]: https://golang.org/
+[9]: https://opensource.com/sites/default/files/uploads/image4.png (gophers hacking together)
+[10]: https://en.wikipedia.org/wiki/Deadlock
+[11]: https://opensource.com/sites/default/files/uploads/image5_0_0.jpg (gophers on a wire, talking)
+[12]: https://golang.org/doc/articles/race_detector.html
+[13]: https://opensource.com/sites/default/files/uploads/image6.jpeg (gopher assembly line)
+[14]: https://en.wikipedia.org/wiki/Monitor_%28synchronization%29#Condition_variables
+[15]: https://opensource.com/sites/default/files/uploads/image7.png (gopher boot camp)
diff --git a/sources/tech/20191211 Enable your Python game player to run forward and backward.md b/sources/tech/20191211 Enable your Python game player to run forward and backward.md
new file mode 100644
index 0000000000..fb9b020278
--- /dev/null
+++ b/sources/tech/20191211 Enable your Python game player to run forward and backward.md
@@ -0,0 +1,474 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Enable your Python game player to run forward and backward)
+[#]: via: (https://opensource.com/article/19/12/python-platformer-game-run)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Enable your Python game player to run forward and backward
+======
+Let your player run free by enabling the side-scroller effect in your
+Python platformer using the Pygame module.
+![Gaming artifacts with joystick, GameBoy, paddle][1]
+
+This is part 8 in an ongoing series about creating video games in Python 3 using the Pygame module. Previous articles are:
+
+ * [Learn how to program in Python by building a simple dice game][2]
+ * [Build a game framework with Python using the Pygame module][3]
+ * [How to add a player to your Python game][4]
+ * [Using Pygame to move your game character around][5]
+ * [What's a hero without a villain? How to add one to your Python game][6]
+ * [Simulate gravity in your Python game][7]
+ * [Add jumping to your Python platformer game][8]
+
+
+
+In previous entries in this series about creating video games in [Python 3][9] using the [Pygame][10] module, you designed your level-design layout, but some portion of your level probably extended past your viewable screen. The ubiquitous solution to that problem in platformer games is, as the term "side-scroller" suggests, scrolling.
+
+The key to scrolling is to make the platforms around the player sprite move when the player sprite gets close to the edge of the screen. This provides the illusion that the screen is a "camera" panning across the game world.
+
+This scrolling trick requires two dead zones at either edge of the screen, at which point your avatar stands still while the world scrolls by.
+
+### Putting the scroll in side-scroller
+
+You need one trigger point to go forward and another if you want your player to be able to go backward. These two points are simply two variables. Set them each about 100 or 200 pixels from each screen edge. Create the variables in your **setup** section. In the following code, the first two lines are for context, so just add the last two lines:
+
+
+```
+player_list.add(player)
+steps = 10
+forwardX = 600
+backwardX = 230
+```
+
+In the main loop, check to see if your player sprite is at the **forwardx** or **backwardx** scroll point. If so, move all platforms either left or right, depending on whether the world is moving forward or backward. In the following code, the final three lines of code are only for your reference:
+
+
+```
+ # scroll the world forward
+ if player.rect.x >= forwardx:
+ scroll = player.rect.x - forwardx
+ player.rect.x = forwardx
+ for p in plat_list:
+ p.rect.x -= scroll
+
+ # scroll the world backward
+ if player.rect.x <= backwardx:
+ scroll = backwardx - player.rect.x
+ player.rect.x = backwardx
+ for p in plat_list:
+ p.rect.x += scroll
+
+ ## scrolling code above
+ world.blit(backdrop, backdropbox)
+ player.gravity() # check gravity
+ player.update()
+```
+
+Launch your game and try it out.
+
+![Scrolling the world in Pygame][11]
+
+Scrolling works as expected, but you may notice a small problem that happens when you scroll the world around your player and non-player sprites: the enemy sprite doesn't scroll along with the world. Unless you want
+
+your enemy sprite to pursue your player endlessly, you need to modify the enemy code so that when your player makes an expeditious retreat, the enemy is left behind.
+
+### Enemy scroll
+
+In your main loop, you must apply the same rules for scrolling platforms to your enemy's position. Because your game world will (presumably) have more than one enemy in it, the rules are applied to your enemy list rather than an individual enemy sprite. That's one of the advantages of grouping similar elements into lists.
+
+The first two lines are for context, so just add the final two to your main loop:
+
+
+```
+ # scroll the world forward
+ if player.rect.x >= forwardx:
+ scroll = player.rect.x - forwardx
+ player.rect.x = forwardx
+ for p in plat_list:
+ p.rect.x -= scroll
+ for e in enemy_list:
+ e.rect.x -= scroll
+```
+
+To scroll in the other direction:
+
+
+```
+ # scroll the world backward
+ if player.rect.x <= backwardx:
+ scroll = backwardx - player.rect.x
+ player.rect.x = backwardx
+ for p in plat_list:
+ p.rect.x += scroll
+ for e in enemy_list:
+ e.rect.x += scroll
+```
+
+Launch the game again and see what happens.
+
+Here's all the code you've written for this Python platformer so far:
+
+
+```
+#!/usr/bin/env python3
+# draw a world
+# add a player and player control
+# add player movement
+# add enemy and basic collision
+# add platform
+# add gravity
+# add jumping
+# add scrolling
+
+# GNU All-Permissive License
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved. This file is offered as-is,
+# without any warranty.
+
+import pygame
+import sys
+import os
+
+'''
+Objects
+'''
+
+class Platform(pygame.sprite.Sprite):
+ # x location, y location, img width, img height, img file
+ def __init__(self,xloc,yloc,imgw,imgh,img):
+ pygame.sprite.Sprite.__init__(self)
+ self.image = pygame.image.load(os.path.join('images',img)).convert()
+ self.image.convert_alpha()
+ self.rect = self.image.get_rect()
+ self.rect.y = yloc
+ self.rect.x = xloc
+
+class Player(pygame.sprite.Sprite):
+ '''
+ Spawn a player
+ '''
+ def __init__(self):
+ pygame.sprite.Sprite.__init__(self)
+ self.movex = 0
+ self.movey = 0
+ self.frame = 0
+ self.health = 10
+ self.collide_delta = 0
+ self.jump_delta = 6
+ self.score = 1
+ self.images = []
+ for i in range(1,9):
+ img = pygame.image.load(os.path.join('images','hero' + str(i) + '.png')).convert()
+ img.convert_alpha()
+ img.set_colorkey(ALPHA)
+ self.images.append(img)
+ self.image = self.images[0]
+ self.rect = self.image.get_rect()
+
+ def jump(self,platform_list):
+ self.jump_delta = 0
+
+ def gravity(self):
+ self.movey += 3.2 # how fast player falls
+
+ if self.rect.y > worldy and self.movey >= 0:
+ self.movey = 0
+ self.rect.y = worldy-ty
+
+ def control(self,x,y):
+ '''
+ control player movement
+ '''
+ self.movex += x
+ self.movey += y
+
+ def update(self):
+ '''
+ Update sprite position
+ '''
+
+ self.rect.x = self.rect.x + self.movex
+ self.rect.y = self.rect.y + self.movey
+
+ # moving left
+ if self.movex < 0:
+ self.frame += 1
+ if self.frame > ani*3:
+ self.frame = 0
+ self.image = self.images[self.frame//ani]
+
+ # moving right
+ if self.movex > 0:
+ self.frame += 1
+ if self.frame > ani*3:
+ self.frame = 0
+ self.image = self.images[(self.frame//ani)+4]
+
+ # collisions
+ enemy_hit_list = pygame.sprite.spritecollide(self, enemy_list, False)
+ for enemy in enemy_hit_list:
+ self.health -= 1
+ #print(self.health)
+
+ plat_hit_list = pygame.sprite.spritecollide(self, plat_list, False)
+ for p in plat_hit_list:
+ self.collide_delta = 0 # stop jumping
+ self.movey = 0
+ if self.rect.y > p.rect.y:
+ self.rect.y = p.rect.y+ty
+ else:
+ self.rect.y = p.rect.y-ty
+
+ ground_hit_list = pygame.sprite.spritecollide(self, ground_list, False)
+ for g in ground_hit_list:
+ self.movey = 0
+ self.rect.y = worldy-ty-ty
+ self.collide_delta = 0 # stop jumping
+ if self.rect.y > g.rect.y:
+ self.health -=1
+ print(self.health)
+
+ if self.collide_delta < 6 and self.jump_delta < 6:
+ self.jump_delta = 6*2
+ self.movey -= 33 # how high to jump
+ self.collide_delta += 6
+ self.jump_delta += 6
+
+class Enemy(pygame.sprite.Sprite):
+ '''
+ Spawn an enemy
+ '''
+ def __init__(self,x,y,img):
+ pygame.sprite.Sprite.__init__(self)
+ self.image = pygame.image.load(os.path.join('images',img))
+ self.movey = 0
+ #self.image.convert_alpha()
+ #self.image.set_colorkey(ALPHA)
+ self.rect = self.image.get_rect()
+ self.rect.x = x
+ self.rect.y = y
+ self.counter = 0
+
+
+ def move(self):
+ '''
+ enemy movement
+ '''
+ distance = 80
+ speed = 8
+
+ self.movey += 3.2
+
+ if self.counter >= 0 and self.counter <= distance:
+ self.rect.x += speed
+ elif self.counter >= distance and self.counter <= distance*2:
+ self.rect.x -= speed
+ else:
+ self.counter = 0
+
+ self.counter += 1
+
+ if not self.rect.y >= worldy-ty-ty:
+ self.rect.y += self.movey
+
+ plat_hit_list = pygame.sprite.spritecollide(self, plat_list, False)
+ for p in plat_hit_list:
+ self.movey = 0
+ if self.rect.y > p.rect.y:
+ self.rect.y = p.rect.y+ty
+ else:
+ self.rect.y = p.rect.y-ty
+
+ ground_hit_list = pygame.sprite.spritecollide(self, ground_list, False)
+ for g in ground_hit_list:
+ self.rect.y = worldy-ty-ty
+
+
+class Level():
+ def bad(lvl,eloc):
+ if lvl == 1:
+ enemy = Enemy(eloc[0],eloc[1],'yeti.png') # spawn enemy
+ enemy_list = pygame.sprite.Group() # create enemy group
+ enemy_list.add(enemy) # add enemy to group
+
+ if lvl == 2:
+ print("Level " + str(lvl) )
+
+ return enemy_list
+
+ def loot(lvl,lloc):
+ print(lvl)
+
+ def ground(lvl,gloc,tx,ty):
+ ground_list = pygame.sprite.Group()
+ i=0
+ if lvl == 1:
+ while i < len(gloc):
+ ground = Platform(gloc[i],worldy-ty,tx,ty,'ground.png')
+ ground_list.add(ground)
+ i=i+1
+
+ if lvl == 2:
+ print("Level " + str(lvl) )
+
+ return ground_list
+
+ def platform(lvl,tx,ty):
+ plat_list = pygame.sprite.Group()
+ ploc = []
+ i=0
+ if lvl == 1:
+ ploc.append((0,worldy-ty-128,3))
+ ploc.append((300,worldy-ty-256,3))
+ ploc.append((500,worldy-ty-128,4))
+
+ while i < len(ploc):
+ j=0
+ while j <= ploc[i][2]:
+ plat = Platform((ploc[i][0]+(j*tx)),ploc[i][1],tx,ty,'ground.png')
+ plat_list.add(plat)
+ j=j+1
+ print('run' + str(i) + str(ploc[i]))
+ i=i+1
+
+ if lvl == 2:
+ print("Level " + str(lvl) )
+
+ return plat_list
+
+'''
+Setup
+'''
+worldx = 960
+worldy = 720
+
+fps = 40 # frame rate
+ani = 4 # animation cycles
+clock = pygame.time.Clock()
+pygame.init()
+main = True
+
+BLUE = (25,25,200)
+BLACK = (23,23,23 )
+WHITE = (254,254,254)
+ALPHA = (0,255,0)
+
+world = pygame.display.set_mode([worldx,worldy])
+backdrop = pygame.image.load(os.path.join('images','stage.png')).convert()
+backdropbox = world.get_rect()
+player = Player() # spawn player
+player.rect.x = 0
+player.rect.y = 0
+player_list = pygame.sprite.Group()
+player_list.add(player)
+steps = 10
+forwardx = 600
+backwardx = 230
+
+eloc = []
+eloc = [200,20]
+gloc = []
+#gloc = [0,630,64,630,128,630,192,630,256,630,320,630,384,630]
+tx = 64 #tile size
+ty = 64 #tile size
+
+i=0
+while i <= (worldx/tx)+tx:
+ gloc.append(i*tx)
+ i=i+1
+
+enemy_list = Level.bad( 1, eloc )
+ground_list = Level.ground( 1,gloc,tx,ty )
+plat_list = Level.platform( 1,tx,ty )
+
+'''
+Main loop
+'''
+while main == True:
+ for event in pygame.event.get():
+ if event.type == pygame.QUIT:
+ pygame.quit(); sys.exit()
+ main = False
+
+ if event.type == pygame.KEYDOWN:
+ if event.key == pygame.K_LEFT or event.key == ord('a'):
+ print("LEFT")
+ player.control(-steps,0)
+ if event.key == pygame.K_RIGHT or event.key == ord('d'):
+ print("RIGHT")
+ player.control(steps,0)
+ if event.key == pygame.K_UP or event.key == ord('w'):
+ print('jump')
+
+ if event.type == pygame.KEYUP:
+ if event.key == pygame.K_LEFT or event.key == ord('a'):
+ player.control(steps,0)
+ if event.key == pygame.K_RIGHT or event.key == ord('d'):
+ player.control(-steps,0)
+ if event.key == pygame.K_UP or event.key == ord('w'):
+ player.jump(plat_list)
+
+ if event.key == ord('q'):
+ pygame.quit()
+ sys.exit()
+ main = False
+
+ # scroll the world forward
+ if player.rect.x >= forwardx:
+ scroll = player.rect.x - forwardx
+ player.rect.x = forwardx
+ for p in plat_list:
+ p.rect.x -= scroll
+ for e in enemy_list:
+ e.rect.x -= scroll
+
+ # scroll the world backward
+ if player.rect.x <= backwardx:
+ scroll = backwardx - player.rect.x
+ player.rect.x = backwardx
+ for p in plat_list:
+ p.rect.x += scroll
+ for e in enemy_list:
+ e.rect.x += scroll
+
+ world.blit(backdrop, backdropbox)
+ player.gravity() # check gravity
+ player.update()
+ player_list.draw(world) #refresh player position
+ enemy_list.draw(world) # refresh enemies
+ ground_list.draw(world) # refresh enemies
+ plat_list.draw(world) # refresh platforms
+ for e in enemy_list:
+ e.move()
+ pygame.display.flip()
+ clock.tick(fps)
+```
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/python-platformer-game-run
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/open_gaming_games_roundup_news.png?itok=KM0ViL0f (Gaming artifacts with joystick, GameBoy, paddle)
+[2]: https://opensource.com/article/17/10/python-101
+[3]: https://opensource.com/article/17/12/game-framework-python
+[4]: https://opensource.com/article/17/12/game-python-add-a-player
+[5]: https://opensource.com/article/17/12/game-python-moving-player
+[6]: https://opensource.com/article/18/5/pygame-enemy
+[7]: https://opensource.com/article/19/11/simulate-gravity-python
+[8]: https://opensource.com/article/19/12/jumping-python-platformer-game
+[9]: https://www.python.org/
+[10]: https://www.pygame.org/news
+[11]: https://opensource.com/sites/default/files/uploads/pygame-scroll.jpg (Scrolling the world in Pygame)
diff --git a/sources/tech/20191211 Revamp your old Linux desktop with Joe-s Window Manager.md b/sources/tech/20191211 Revamp your old Linux desktop with Joe-s Window Manager.md
new file mode 100644
index 0000000000..97240d2de9
--- /dev/null
+++ b/sources/tech/20191211 Revamp your old Linux desktop with Joe-s Window Manager.md
@@ -0,0 +1,78 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Revamp your old Linux desktop with Joe's Window Manager)
+[#]: via: (https://opensource.com/article/19/12/joes-window-manager-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Revamp your old Linux desktop with Joe's Window Manager
+======
+This article is part of a special series of 24 days of Linux desktops.
+JWM's meager weight and simplicity makes it a great window manager for
+slow or old Linux computers.
+![and old computer and a new computer, representing migration to new software or hardware][1]
+
+Joe's Window Manager ([JWM][2] for short) is a lightweight window manager for X11. It's written in C, minimally using [Xlib][3]. Because it's so small and simple, JWM makes a great window manager for slow or old computers. The Raspberry Pi barely registers that JWM is running, leaving precious system resources for more important tasks than the desktop.
+
+JWM follows in the footsteps of environments like FVWM, Window Maker, and Fluxbox. It provides an application menu, window decoration, and a panel with an application menu, taskbar, and clock.
+
+Install JWM from your distribution's software repository. After installing it, log out of your current desktop session so you can log into JWM. By default, your session manager (KDM, GDM, LightDM, or XDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+To select a new desktop with GDM:
+
+![Select your desktop session in GDM][4]
+
+With KDM:
+
+![Select your desktop session with KDM][5]
+
+The first time you log into JWM, you may find a black screen with a panel at the bottom. It's normal on most distributions to let you choose the wallpaper for this minimal desktop. You can set a wallpaper with the **feh** command (you may need to install it from your repository). This command has a few options for setting the background, including **\--bg-fill** to fill the screen with your wallpaper of choice, **\--bg-scale** to scale it to fit, and so on.
+
+
+```
+`$ feh --bg-fill ~/Pictures/wallpapers/mybackground.jpg`
+```
+
+### Application menu
+
+There are two locations for the application menus in JWM: it appears at your mouse cursor when you left-click on the desktop, and it is also available by clicking the JWM logo in the lower-left corner.
+
+![JWM running on Debian][6]
+
+There aren't any applications bundled with JWM, so it's up to you to decide what applications to use. You can get applications from any desktop, like GNOME or KDE, or you can use independent applications. Most of the integration between applications is done by [D-Bus][7] and other backend technology on Linux, so it's safe to mix and match them. I use [PCManFM-Qt][8] as a file manager, [unicode-rxvt][9] as a terminal, and, of course, Firefox as an internet browser.
+
+### Configuration
+
+Two configuration files govern JWM. The system-wide configuration file is **/etc/jwm/system.jwmrc**, and the user local file is **$HOME/.jwmrc**. Configuration files are written in XML, but the schema is very basic and easy to reverse-engineer, whether you know XML or not. Configuration options are well-documented on [Joewing.net][10], home of the JWM project.
+
+### Why you should use JWM
+
+There's no shortage of lightweight window managers available for Linux, and you might wonder why there seems to be so much redundancy, much less why you should try Joe's. There are a few reasons JWM is as important as any of the others. When looking at software projects, redundancy is a _good thing_. Should one project's implementation of a desktop paradigm fade, you have many others to choose from. And often, the strengths of each project are in the minor details. For example, the quick and easy setup of a taskbar and application menu makes for a quick, sensible default configuration for all the users who want that common setup. For technical users, the XML configuration may be a refreshing change from the custom configuration formats in other environments.
+
+Joe's Window Manager, in a way, demonstrates the rich diversity of open source and how it's a luxury Linux users enjoy. If you're interested in JWM, try it out today, and see if you can make your own window manager, too.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/joes-window-manager-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/migration_innovation_computer_software.png?itok=VCFLtd0q (and old computer and a new computer, representing migration to new software or hardware)
+[2]: http://joewing.net/projects/jwm/
+[3]: https://en.wikipedia.org/wiki/Xlib
+[4]: https://opensource.com/sites/default/files/advent-gdm_0.jpg (Select your desktop session in GDM)
+[5]: https://opensource.com/sites/default/files/advent-kdm.jpg (Select your desktop session with KDM)
+[6]: https://opensource.com/sites/default/files/uploads/advent-jwm_675px.jpg (JWM running on Debian)
+[7]: https://en.wikipedia.org/wiki/D-Bus
+[8]: https://blog.lxqt.org/category/pcmanfm-qt/
+[9]: https://opensource.com/article/19/10/why-use-rxvt-terminal
+[10]: http://joewing.net/projects/jwm/config-2.3.html
diff --git a/sources/tech/20191212 15 Useful Firefox Keyboard Shortcuts You Should Know.md b/sources/tech/20191212 15 Useful Firefox Keyboard Shortcuts You Should Know.md
new file mode 100644
index 0000000000..345802439f
--- /dev/null
+++ b/sources/tech/20191212 15 Useful Firefox Keyboard Shortcuts You Should Know.md
@@ -0,0 +1,129 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (15 Useful Firefox Keyboard Shortcuts You Should Know)
+[#]: via: (https://itsfoss.com/firefox-keyboard-shortcuts/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+15 Useful Firefox Keyboard Shortcuts You Should Know
+======
+
+[Firefox][1] is one of the most popular free and open-source browsers for Linux users. Even though you have a lot of [open source chrome alternatives][2], Firefox still is one of the best choices to go with.
+
+And you don’t even need to [install Firefox on Ubuntu][3] or most other distributions because it is installed by default.
+
+What if you can make your browsing experience on Firefox even better by using some keyboard shortcuts?
+
+Hold on, of course, not everyone prefers to use keyboard shortcuts. But, if you’re comfortable with that and want to do perform tasks in a jiffy, you should know some of the most common Firefox keyboard shortcuts.
+
+It is also worth noting that you could use some of these shortcuts on Chrome/Chromium as well- however, we already have a list of [useful Google Chrome shortcuts][4] to help you out. So, if you’re using Chrome/Chromium, I insist you check out that article.
+
+### 15 Useful Firefox Keyboard Shortcuts
+
+![][5]
+
+You could always refer to the [official documentation][6] of keyboard shortcuts for Firefox. However, that’s a very long list, and you probably do not need to use all of that.
+
+So, here, I shall be listing the most commonly used (and useful) keyboard shortcuts that you can use on Firefox. To be honest, these are the shortcuts that I use most frequently on Firefox.
+
+#### 1\. Open A New Tab
+
+You don’t have to hover your cursor over to the **+** sign in the browser.
+
+Simply press **CTRL + T** to open a new tab in the same window.
+
+#### 2\. Open A New Tab In A New Window
+
+If you want to open up a new window along with a new tab, you just have to press **CTRL + N**.
+
+#### 3\. Close A Tab
+
+Lazy to use your mouse to navigate and close the tab? Fret not, just press **CTRL + W** to make your active tab vanish!
+
+#### 4\. Open A New Private Window
+
+Don’t want to store the history/cookies for a specific browsing session? You can try the private mode by pressing **CTRL + Shift + P** as the keyboard shortcut for Firefox.
+
+#### 5\. Open Recently Closed Tabs
+
+If you closed a tab recently (or a number of tabs), just press **CTRL + Shift + T** till you get all your closed tabs restored.
+
+#### 6\. Reload Webpage
+
+You might want to reload a webpage quickly, to do that press **F5**.
+
+If you want to ignore the cached content and want to fetch a new copy of the webpage, you can try **CTRL + F5**.
+
+#### 7\. Scroll Up/Down Webpage
+
+You can also scroll up/down using just your keyboard.
+
+Simply use **PAGE UP** to scroll up and **PAGE DOWN** key to scroll down.
+
+#### 8\. Find A Text In Webpage
+
+You do not need to endlessly look for a word on a webpage just like you would in a physical book.
+
+Simply press **CTRL + F** and then type in the exact word, it should highlight the matching words if it exists.
+
+#### 9\. Close Your Browser At Once
+
+Hit **CTRL + Shift + W** to close all the tabs in one go. However, you might get the prompt to confirm it.
+
+#### 10\. View The Page Source
+
+If you’re interested to take peek at the webpage’s source code, you just have to press **CTRL + U** to open view source in a new tab.
+
+#### 11\. Switch Tabs Quickly
+
+If you have multiple tabs opened up, you can easily navigate through them by pressing:
+
+**CTRL + Tab**.
+
+#### 12\. View Your Downloads
+
+Do you want to quickly take a look at your download library? All you need to do is press:
+
+**CTRL + Shift + Y**
+
+#### 13\. Bookmark A Webpage
+
+To bookmark a webpage, hit **CTRL + D** and press the **ENTER** key to save it.
+
+#### 14\. Select the Address/Search Bar
+
+If you want to search for something through the address bar, hit **CTRL + L** to immediately highlight the search bar for you.
+
+#### 15\. Check Browsing History
+
+Usually, it needs a couple of clicks to view your history. But, you can just press **CTRL + H** to launch the sidebar to view your history right away.
+
+### Wrapping Up
+
+As I mentioned, you will find a huge list of Firefox keyboard shortcuts if you take a look at their [official documentation][6].
+
+If you want to explore more options, feel free to check the documentation. In either case, the mentioned keyboard shortcuts should come pretty handy.
+
+I’ll be interested to know what Firefox keyboard shortcuts do you use? Let me know your thoughts in the comments below.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/firefox-keyboard-shortcuts/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://www.mozilla.org/en-US/firefox/
+[2]: https://itsfoss.com/open-source-browsers-linux/
+[3]: https://itsfoss.com/firefox-quantum-ubuntu/
+[4]: https://itsfoss.com/google-chrome-shortcuts/
+[5]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/Firefox_Keyboard_Shortcuts.jpg?ssl=1
+[6]: https://developer.mozilla.org/en-US/docs/Tools/Keyboard_shortcuts
diff --git a/sources/tech/20191213 How to generate code with Apache Velocity.md b/sources/tech/20191213 How to generate code with Apache Velocity.md
new file mode 100644
index 0000000000..ad431b0a55
--- /dev/null
+++ b/sources/tech/20191213 How to generate code with Apache Velocity.md
@@ -0,0 +1,88 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to generate code with Apache Velocity)
+[#]: via: (https://opensource.com/article/19/12/generate-code-apache-velocity)
+[#]: author: (Girish Managoli https://opensource.com/users/gammay)
+
+How to generate code with Apache Velocity
+======
+Get started with Velocity, an open source, Java-based template engine
+and code generator that converts templates into source code.
+![Binary code on a computer screen][1]
+
+Apache [Velocity][2] is an open source, Java-based template engine and code generator that converts templates into source code. Because it is implemented in Java, it is capable of interpreting varied templates and generating code for any language (web, service, SQL, scripts, etc.), although it seems to be oriented mostly toward web development.
+
+## Velocity's structure
+
+Velocity's structure is comprised of an engine and tools. Its core is the Velocity Engine, which uses the defined template, interprets the template language, and generates the code.
+
+Templates are defined with Velocity Template Language ([VTL][3]), a simple language with effective directives. VTL statements are directives or variables, and variables can be standalone or class methods.
+
+Examples of VTL expressions include:
+
+
+```
+`package ${packagename};`[/code] | Inserts a package statement in Java where the package name is defined as **packagename**
+---|---
+```
+`public ${classname} implements Serializable {`[/code] | Adds a class with name **classname**
+
+```
+ #foreach( $property in $properties )
+ public ${property.fieldType} get${property.getField()}() {
+ return this.${property.fieldName};
+ }
+#end [/code] | Creates getter methods for all defined properties
+
+Velocity tools are collections of basic user-friendly capabilities. There are [GenericTools][4], a "set of classes that provide basic infrastructure for using tools in standard Java SE Velocity projects, as well as a set of tools for use in generic Velocity templates." They include DateTool, MathTool, NumberTool, SortTool, and XmlTool. There are also [VelocityView][5] tools, which include "all of the GenericTools and adds infrastructure and specialized tools for using Velocity in the view layer of web applications (Java EE projects)." VelocityView tools include BrowserTool, CookieTool, and ImportTool
+
+## Velocity advantages and disadvantages
+
+Velocity is easy to use and has the capability to generate any language. On the downside, there is a learning curve to understand and apply its template language. Velocity is morphology- and ontology-free. It has no knowledge of the design capability of the module it generates. As a practical example, Velocity may use a template for a controller (e.g., Model-View-Controller or an architecture style) and generate the code, but it has no awareness of the concept of a controller. This is both an advantage and disadvantage, with a generator being simple and easy to use but with no awareness of the design's aptitude.
+
+## Using Velocity
+
+Velocity's Java library is available on the [Maven repository][6]. To use the .jar file, define Velocity's latest version in your Maven build config. (Velocity 1.7 is the latest version, as of this writing.) For example, enter the following in your Maven Project Object Model (POM):
+```
+
+
+<dependency>
+ <groupId>org.apache.velocity</groupId>
+ <artifactId>velocity</artifactId>
+ <version>1.7</version>
+</dependency>
+
+```
+### Java Hello World example
+
+To generate code, you need two things:
+
+ 1. The **Velocity template** to be used for generation, e.g., java_example.vm: [code] public class ${className} {
+
+ public static void main([String][7][] args) {
+ [System][8].out.println("${message}");
+ }
+
+}
+```
+
+
+
+ 2. The **Velocity generator** that uses the template to generate code, e.g., VelocityStartGenerator.java: [code] public class VelocityStartGenerator {
+
+ static [String][7] inputTemplate = "java_example.vm";
+ static [String][7] className = "VelocityExample";
+ static [String][7] message = "Hello World!";
+ static [String][7] outputFile = className + ".java";
+
+ public static void main([String][7][] args) throws [IOException][9] {
+
+ VelocityEngine velocityEngine = new VelocityEngine();
+ velocityEngine.init();
+
+ VelocityContext context = new VelocityContext();
+ context.put("className", className);
+
\ No newline at end of file
diff --git a/sources/tech/20191213 Why you need to know about Seeed hardware devices.md b/sources/tech/20191213 Why you need to know about Seeed hardware devices.md
new file mode 100644
index 0000000000..eec34577da
--- /dev/null
+++ b/sources/tech/20191213 Why you need to know about Seeed hardware devices.md
@@ -0,0 +1,121 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Why you need to know about Seeed hardware devices)
+[#]: via: (https://opensource.com/article/19/12/seeeduino-nano-review)
+[#]: author: (Alan Smithee https://opensource.com/users/alansmithee)
+
+Why you need to know about Seeed hardware devices
+======
+Learn how Seeed microcontrollers solve the problem of building modular
+projects.
+![Multi-colored and directional network computer cables][1]
+
+The microcontroller craze doesn't seem to be dying down—and that's a good thing because these products consistently succeed where the mobile market consistently fails: Users get open software _and hardware_, a portable form factor, and a wide choice of vendors and products that are built to last.
+
+Among the best of the open hardware and software vendors is [Seeed][2], the self-proclaimed "IoT Hardware Enabler." I recently started seeing the Seeed logo on projects, so I contacted the company to learn about the interesting things they're doing. In response, they generously sent me one of their latest products: the [Seeeduino Nano][3], a compact board that the company says is fully compatible with the Arduino Nano but at half the price and a quarter the size, along with a sample sensor to get me started.
+
+I spent a few days with it, and I'm already working on a project to improve my home garden and thinking of several others for home automation. Far from just another Arduino-like product, the Seeeduino Nano solves several problems new makers face when they get a microcontroller and want to use it.
+
+### What do I do with this?
+
+The most common problem I hear from people underwhelmed by the Raspberry Pi, Arduino, or similar microcontroller is that they excitedly got a board, stepped through its tutorial, and then realized they didn't know what to do with it. As computer users, we're not used to purpose-driven devices. You get a computer-like device and use it for many purposes, so it feels strange to get a computing device and build it into a project.
+
+It can also be a little overwhelming to get a microcontroller. It's full of potential, but it's also just a microcontroller. It can be intimidating to figure out what kind of project to start when you have a device that apparently is capable of anything.
+
+Seeed has a line of input and output peripherals (they call it Grove) that are easy to connect and provide an easy way to modularly build projects based on what kind of information you want to process. There's nothing special about the Grove modules compared to sensors or servos you can get for any other device, but Seeed makes what can sometimes seem to be an overwhelming number of choices a lot more navigable. And better yet, Seeed provides libraries for each Grove module, so you'll never buy a part for your project then find that you don't know how to make your controller recognize it.
+
+Because Seeed sent me a temperature and humidity sensor, my potential projects, at least in the short term, became highly focused. I knew I'd be designing either a thermometer and humidity detector for my home or a moisture monitor for some of my favorite plants. Based on the other Grove modules, I've come up with several more projects, too.
+
+### Clean connectors
+
+What makes the Grove modules especially nice is that they're based around I2C connectors. That means you can turn this:
+
+![Cables and pins and alligator clips][4]
+
+into this:
+
+![The Seeeduino Nano with a Grove module connected][5]
+
+Of course, you can also solve that problem with any number of attachments for a Pi or Arduino or whatever product you happen to own, but the Seeed and Grove are built for one another, so if you're embarking on a new project, this is an easy way to keep things under control from the start.
+
+### Small footprint
+
+The Seeeduino Nano is small. It's just 18mm by 43mm (that's about 1.5" by 1"), yet it has eight analog pins, 14 digital pins, and features the ATmega328P 8-bit AVR microcontroller. If your project has space issues, this is a great option.
+
+![Seeeduino Nano microcontroller][6]
+
+The sensors tend to be small, too. Size varies depending on what you purchase, but they're generally designed to save space.
+
+![The Grove temperature and humidity pro \(left\) and a US quarter \(right\)][7]
+
+### Setup
+
+Getting started with the Seeeduino Nano was as easy as getting started with an Arduino. That's not always the case with Arduino-like products, because some of them assume you know the components they're built from. You might get a microcontroller, download the Arduino IDE, and discover that the product you purchased isn't an option in the Board menu, leaving you to guess which Arduino board yours is equivalent to. Seeed leaves nothing to chance and provides board definitions for all of its products. You have to import them yourself since they don't ship with the Arduino IDE, but the [Seeed wiki][8] provides instructions on how to do that through the IDE's Board Manager interface.
+
+After you've imported the board definition, you can either start with the ritual flashing of the Blink code onto your device or just code in the Arduino IDE as usual. There are instructions on the Seeed wiki for that, too.
+
+### Code
+
+In addition to board definitions, Seeed provides sample code for each Grove module, so you know how to send data to the module or gather data from it. I was using the Temperature and Humidity Pro sensor, which requires the [DHT library][9]. Seeed provides the library along with a DHTtester [project][10], and instructions on how to install it are on its wiki.
+
+The only thing Seeed doesn't provide is the name of the correct input pin for the Grove module. The project's example code, written by [LadyAda][11], uses the first analog pin (A0), but, on the Seeeduino Nano, the Grove attaches to what turns out to be A5. This is difficult to tell by looking at it, because the Grove physically attaches to the I2C plug, with no indication of what pin it's connected to. However, the Seeed is open source, so you can either look at the specs for the board, or you can just do what these kinds of gadgets beg you to do: experiment!
+
+In the end, the basic code to get information from the Grove humidity and temperature sensor is about 20 lines of code (25 if you build in sanity checks, as LadyAda's code does):
+
+
+```
+// public domain code by ladyada
+#include "DHT.h"
+#define DHTPIN A5
+#define DHTTYPE DHT22
+
+DHT dht(DHTPIN, DHTTYPE);
+
+void setup() {
+ Serial.begin(9600);
+ dht.begin(); }
+
+void loop() {
+ float h = dht.readHumidity();
+ float t = dht.readTemperature();
+ Serial.print("Humidity: ");
+ Serial.print(h);
+ Serial.print(" %\t");
+ Serial.print("Temperature: ");
+ Serial.print(t);
+ Serial.println(" *C"); }
+```
+
+### Open source everything
+
+The Seeeduino is open source, from the [downloadable Eagle file][12] to the [software][13] that helps you drive it. It's a dream platform for new users who feel overwhelmed by confusing and disparate choices or for experienced makers who have moved on from a prototype and are ready to build a neatly organized and cleanly wired project. If you've got a budding inventor in your life, let Seeed help seed their projects.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/seeeduino-nano-review
+
+作者：[Alan Smithee][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/alansmithee
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/connections_wires_sysadmin_cable.png?itok=d5WqHmnJ (Multi-colored and directional network computer cables)
+[2]: http://seeedstudio.com
+[3]: http://wiki.seeedstudio.com/Seeeduino-Nano/
+[4]: https://opensource.com/sites/default/files/uploads/rpi-mess.jpg (Cables and pins and alligator clips)
+[5]: https://opensource.com/sites/default/files/uploads/seeeduino-grove.jpg (The Seeeduino Nano with a Grove module connected)
+[6]: https://opensource.com/sites/default/files/uploads/seeeduino-nano-wiki_0.jpg (Seeeduino Nano microcontroller)
+[7]: https://opensource.com/sites/default/files/uploads/tempandhumid.jpg (The Grove temperature and humidity pro (left) and a US quarter (right))
+[8]: http://wiki.seeedstudio.com/
+[9]: https://github.com/Seeed-Studio/Grove_Temperature_And_Humidity_Sensor/releases
+[10]: https://project.seeedstudio.com/
+[11]: https://www.adafruit.com
+[12]: https://github.com/SeeedDocument/Seeeduino-Nano/raw/master/res/Seeeduino%20nano.zip
+[13]: https://github.com/Seeed-Studio
diff --git a/sources/tech/20191214 Make VLC More Awesome With These Simple Tips.md b/sources/tech/20191214 Make VLC More Awesome With These Simple Tips.md
new file mode 100644
index 0000000000..de91a1105b
--- /dev/null
+++ b/sources/tech/20191214 Make VLC More Awesome With These Simple Tips.md
@@ -0,0 +1,131 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Make VLC More Awesome With These Simple Tips)
+[#]: via: (https://itsfoss.com/simple-vlc-tips/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+Make VLC More Awesome With These Simple Tips
+======
+
+[VLC][1] is one of the [best open source video players][2], if not the best. What most people don’t know about it is that it is a lot more than just a video player.
+
+You can do a lot of complex tasks like broadcasting live videos, capturing devices etc. Just open its menu and you’ll see how many options it has.
+
+It’s FOSS has a detailed tutorial discussing some of the [pro VLC tricks][3] but those are way too complicated for normal users.
+
+This is why I am writing another article to show you some of the simple tips that you can use with VLC.
+
+### Do more with VLC with these simple tips
+
+Let’s see what can you do with VLC other than just playing a video file.
+
+#### 1\. Watch YouTube videos with VLC
+
+![][4]
+
+If you do not want to watch the annoying advertisements on [YouTube][5] or simply want a distraction-free experience for watching a YouTube video, you can use VLC.
+
+Yes, it is very easy to stream a YouTube video on VLC.
+
+Simply launch the VLC player, head to the Media settings and click on “**Open Network Stream**” or **CTRL + N** as a shortcut to that.
+
+![][6]
+
+Next, you just have to paste the URL of the video that you want to watch. There are some options to tweak – usually, you should not bother using them. But, if you are curious you can click on the “**Advanced options**” to explore.
+
+You can also add subtitles to the YouTube videos this way. However, an easier way to [watch YouTube or any online video with subtitles is using Penguin subtitle player][7].
+
+#### 2\. Convert videos to different formats
+
+![][8]
+
+You can [use ffmpeg to convert videos in Linux command line][9]. You can also use a graphical tool like [HandBrake to convert video formats][10].
+
+But if you do not want a separate app to transcode videos, you can use VLC media player to get the job done.
+
+To do that, just head on to the Media option on VLC and then click on “**Convert/Save**” or press CTRL + R as a shortcut to get there while you have VLC media player active.
+
+Next, you will need to either import the video from your computer/disk or paste the URL of the video that you want to save/convert.
+
+Whatever your input source is – just hit the “**Convert/Save**” button after selecting the file.
+
+Now, you will find another window that gives you the option to change the “**Profile**” from the settings. Click on it and choose a format that you’d like the video to be converted to (and saved).
+
+You can also change the storage path for the converted file by setting the destination folder at the bottom of the screen before converting it.
+
+#### 3\. Record Audio/Video From Source
+
+![Vlc Advanced Controls][11]
+
+Do you want to record the audio/video you’re playing on VLC Media Player?
+
+If yes, there’s an easy solution to that. Simply navigate your way through **View->click on “Advanced Controls”**.
+
+Once you do that, you should observe new buttons (including a red record button in your VLC player).
+
+#### 4\. Download subtitles automatically
+
+![][12]
+
+Yes, you can [automatically download subtitles with VLC][13]. You do not even have to look for it on a separate website. You just have to navigate your way to **View->VLSub**.
+
+By default, it is deactivated, so when you click on the option it gets activated and lets you search/download the subtitles you wanted.
+
+[VLC also lets you synchronize the subtitles][14] with simple keyboard shortcuts.
+
+#### 5\. Take A Snapshot
+
+![][15]
+
+With VLC, you can get some screenshots/images of the video while watching it.
+
+You just need to right-click on the player while the video is playing/paused, you will notice a bunch of options now, navigate through **Video->Take Snapshot**.
+
+If you have an old version installed, you might observe the snapshot option right after performing a right-click.
+
+#### Bonus Tip: Add Audio/Video Effects to a video
+
+From the menu, go to the “**Tools**” option. Now, click on “**Effects and Filters**” or simply press **CTRL + E** from the VLC player window to open up the option.
+
+Here, you can observe audio effects and video effects that you can add to your video. You may not be able to see all the changes in real-time, so you will have to tweak it and save it in order to see what happens.
+
+![][16]
+
+I’ll suggest keeping a backup of the original video before you modify the video.
+
+#### What’s your favorite VLC tip?
+
+I shared some of my favourite VLC tips. Do you know some cool tip that you use regularly with VLC? Why not share it with us? I may add it to the list here.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/simple-vlc-tips/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://www.videolan.org/
+[2]: https://itsfoss.com/video-players-linux/
+[3]: https://itsfoss.com/vlc-pro-tricks-linux/
+[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/youtube-video-stream.jpg?ssl=1
+[5]: https://www.youtube.com/
+[6]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/youtube-video-play.jpg?ssl=1
+[7]: https://itsfoss.com/penguin-subtitle-player/
+[8]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/vlc-video-convert.jpg?ssl=1
+[9]: https://itsfoss.com/ffmpeg/
+[10]: https://itsfoss.com/handbrake/
+[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/vlc-advanced-controls.png?ssl=1
+[12]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/vlc-subtitles-automatic.png?ssl=1
+[13]: https://itsfoss.com/download-subtitles-automatically-vlc-media-player-ubuntu/
+[14]: https://itsfoss.com/how-to-synchronize-subtitles-with-movie-quick-tip/
+[15]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/vlc-snapshot.png?ssl=1
+[16]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/vlc-effects-screenshot.jpg?ssl=1
diff --git a/sources/tech/20191215 Customize your Linux desktop with the Trinity Desktop Environment.md b/sources/tech/20191215 Customize your Linux desktop with the Trinity Desktop Environment.md
new file mode 100644
index 0000000000..561e90d771
--- /dev/null
+++ b/sources/tech/20191215 Customize your Linux desktop with the Trinity Desktop Environment.md
@@ -0,0 +1,65 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Customize your Linux desktop with the Trinity Desktop Environment)
+[#]: via: (https://opensource.com/article/19/12/linux-trinity-desktop-environment-tde)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Customize your Linux desktop with the Trinity Desktop Environment
+======
+This article is part of a special series of 24 days of Linux desktops.
+TDE is a fully customizable Linux desktop that will be instantly
+recognizable to anyone who knew and loved KDE 3.
+![Person standing in front of a giant computer screen with numbers, data][1]
+
+When KDE 4 was released in 2008, KDE 3 went into support mode until support was dropped entirely. That's the usual lifecycle of software, desktops included, but the KDE 3 fanbase wasn't universally pleased with KDE 4, and some of them decided a fork was in order.
+
+Some of them formed a new project with the mission of preserving the look and feel of KDE 3, starting from KDE 3.5.10 (the last official release in the 3.x series), and then forking Qt 3 into TQt to keep the underlying technology updated. Today, the [Trinity Desktop Environment][2] (TDE) delivers a traditional desktop environment that looks and feels essentially the same as KDE 3 did 10-plus years ago.
+
+You may find the Trinity desktop included in the software repository of your distribution. Before you install it, be aware that it is meant to provide a full desktop experience, so many TDE apps are installed along with the desktop. If you're already running another desktop, you may find yourself with redundant applications (two PDF readers, two media players, two file managers, and so on).
+
+If your software repo doesn't offer Trinity, or you just don't want to install it and all of its applications, you can install a TDE distribution in a virtual machine, such as [GNOME Boxes][3]. I used the [exeGNU][4] distribution for the screenshots below, and there are other distros listed on [TDE's LiveCDs][5] page.
+
+### TDE desktop tour
+
+The Trinity Desktop Environment is a very traditional desktop. It's one that's likely to be familiar to you—whether or not you've used KDE at all, in fact. It has one panel at the bottom of the screen that contains an application menu in the left corner, a taskbar in the middle, and a system tray in the right, and there are icons for common locations on the desktop. It behaves exactly as you'd expect a desktop to behave, and you can probably change whatever you want to change because TDE is completely customizable.
+
+If you were a KDE 3 user in the past, revisiting the Trinity Desktop Environment is a little like stepping back in time. While a side-by-side comparison of the two desktops might reveal significant differences, it would be a real challenge to find a deviation in TDE from the desktop you remember. All the key components are there: the sidebar tabs, the Konqueror file manager, the traditional application menu, the retractable panel, and the classic layout.
+
+![TDE on exeGNU][6]
+
+How different this is from KDE 4 or KDE 5 is a matter of perspective. To many users, the TDE default is pretty much the same as the default layout of late KDE 4 or current KDE 5 desktops. As is often the case, however, the biggest differences are in the smallest of details. The absence of Dolphin in favor of [Konqueror][7] is one of the biggest non-changes. Konqueror has quite literally set the standard for both file management and web browsing (KHTML is the code that Apple and Google forked to create the Safari and Chrome browsers), so preserving it as the central desktop application is particularly noteworthy.
+
+All the "old" applications are still there, and seemingly not a button or widget has moved from the old default 3.5 location. The defaults are always set to what they were in KDE 3.5, but nearly everything can be rearranged, changed, hidden, or disassembled. User experience is supreme, and TDE never assumes that any two users want the same experience.
+
+![Trinity Control Center][8]
+
+To a tried and true KDE 3.5.x user, using TDE is just a matter of surrendering to muscle memory.
+
+### Trinity and open source
+
+Trinity, along with the Mate fork of GNOME 2, is one of the most direct examples of how open source empowers developers to sustain a beloved software project that's otherwise reached its end. Not all software is kept alive by a fork and a dedicated team of true believers, but sometimes it does happen, and when it does, it results in greater variety and more choice. Whether you choose KDE 5 or TDE, or GNOME 3 or Mate, you get to make those choices because open source empowers developers and users to make technology work better for everyone.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-trinity-desktop-environment-tde
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/data_metrics_analytics_desktop_laptop.png?itok=9QXd7AUr (Person standing in front of a giant computer screen with numbers, data)
+[2]: https://www.trinitydesktop.org/
+[3]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[4]: http://exegnulinux.net
+[5]: https://wiki.trinitydesktop.org/LiveCDs
+[6]: https://opensource.com/sites/default/files/uploads/advent-trinity.jpg (TDE on exeGNU)
+[7]: https://kde.org/applications/internet/org.kde.konqueror
+[8]: https://opensource.com/sites/default/files/uploads/advent-trinity-control.jpg (Trinity Control Center)
diff --git a/sources/tech/20191215 How to Add Border Around Text in GIMP.md b/sources/tech/20191215 How to Add Border Around Text in GIMP.md
new file mode 100644
index 0000000000..d691bafb41
--- /dev/null
+++ b/sources/tech/20191215 How to Add Border Around Text in GIMP.md
@@ -0,0 +1,139 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to Add Border Around Text in GIMP)
+[#]: via: (https://itsfoss.com/gimp-text-outline/)
+[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
+
+How to Add Border Around Text in GIMP
+======
+
+This simple tutorial explains the steps to outline text in [GIMP][1]. The text outline helps you highlight text against background of other color.
+
+![Outlined Text created in GIMP][2]
+
+Let’s see how can you add a border around your text.
+
+### Adding text outline in GIMP
+
+The entire procedure can be described in these easy steps:
+
+ * Create your text and copy its outlined path
+ * Add a new transparent layer and add the outlined path to this layer
+ * Change the size of the outline, add a different color to it
+
+
+
+That’s all. Don’t worry, I am going to show each steps in detail with proper screenshots. By following this tutorial, you should be able to add outline to text even if you never used GIMP before.
+
+Just make sure that you have [GIMP installed on Linux][3] or whatever operating system you are using.
+
+This tutorial has been performed with GIMP 2.10 version.
+
+#### Step 1: Create your primary text and copy its outline
+
+Open GIMP and create a new file by going to the top menu->File->New. You can also use Ctrl+N keyboard shortcut.
+
+![Create New File][4]
+
+You can select the size of your canvas here. You may also choose if you want white background or a transparent background. It is under the Advanced Options->Color profile.
+
+I have chosen the default white background. It can be changed later.
+
+Now select the Text tool from the toolbox in the left sidebar.
+
+![Adding text in GIMP][5]
+
+Write the text you want. You can change the font, size and alignment of the text as per your choice. I have kept the default left alignment of the text for this article.
+
+I have deliberately chose a light color for the text so that it is difficult to read. I’ll add a darker outline to this light text in this tutorial.
+
+![Text added in GIMP][6]
+
+When you are done writing your text, right click the text box and select **Path from Text**.
+
+![Right click on the text box and select ‘Path from Text’][7]
+
+#### Step 2: Add a transparent layer with the text outline
+
+Now, go to the top menu, go to Layer and add a new layer.
+
+![Use Shift+Ctrl+N to add a new layer][8]
+
+Make sure to add the new layer as transparent. You can give it a suitable name like ‘outline for text’. Click OK to add this transparent layer.
+
+![Add a transparent layer][9]
+
+Go to the menu again and this time go to **Select** and click **From path**. You’ll see that your text has been highlighted.
+
+![Go to Select and choose From Path][10]
+
+Basically, you just created a transparent layer that has the same text (but transparent) as your original text. What you need to do now is to increase the size of the text on this layer.
+
+#### Step 3: Adding the text outline by increasing its size and changing its color
+
+To do that, go to Select in menu once again and this time choose Grow. This will allow you to grow the size of the text on the transparent layer.
+
+![Grow the selection on the additional layer][11]
+
+Grow it by 5 or 10 pixel or whatever you prefer.
+
+![Grow it by 5 or 10 pixel][12]
+
+What you need to do now is to fill this enlarged selection with a choice of your color. Since my original text is of light color, I am going to use back color for the outline here.
+
+**Select your main image layer** if it’s not already selected. The layers are visible at the right sidebar. Then go to the toolbox and select the bucket fill tool. Select the desired color you want for the outline.
+
+Now use the tool to fill black color to your selection. Mind that you fill the outer outline of the text, not the text itself.
+
+![Fill the outline of the text with a different color][13]
+
+You are pretty much done here. Use Ctrl+Shift+A to de-select your current selection.
+
+![Outline added to the text][14]
+
+So now you have successfully added outline to your text in GIMP. It is on white background and if you want a transparent background, just delete the background layer from the layer menu in the right sidebar.
+
+![Remove the white background layer if you want a transparent background][15]
+
+If you are happy with the result, save the file as PNG file (to keep transparent background) or whichever file format you prefer.
+
+**Did you make it work?**
+
+That’s it. That’s all you need to do to add a text outline in GIMP.
+
+I hope you find this GIMP tutorial helpful. You may want to check out another [simple tutorial about adding a watermark in GIMP][16].
+
+If you have questions or suggestions, please feel free to leave a comment below.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/gimp-text-outline/
+
+作者：[Abhishek Prakash][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/abhishek/
+[b]: https://github.com/lujun9972
+[1]: https://www.gimp.org/
+[2]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/outlined_text_GIMP.png?ssl=1
+[3]: https://itsfoss.com/gimp-2-10-release/
+[4]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/12/create_outline_text_gimp_1.jpeg?ssl=1
+[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_2.jpg?ssl=1
+[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp-3.jpg?ssl=1
+[7]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_4.jpg?ssl=1
+[8]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_5.jpg?ssl=1
+[9]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_6.jpg?ssl=1
+[10]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_7.jpg?ssl=1
+[11]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_8.jpg?ssl=1
+[12]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_9.jpg?ssl=1
+[13]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_10.jpg?ssl=1
+[14]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_11.jpg?ssl=1
+[15]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/outline_text_gimp_12.jpg?ssl=1
+[16]: https://itsfoss.com/add-watermark-gimp-linux/
diff --git a/sources/tech/20191216 Relive Linux history with the ROX desktop.md b/sources/tech/20191216 Relive Linux history with the ROX desktop.md
new file mode 100644
index 0000000000..215006514f
--- /dev/null
+++ b/sources/tech/20191216 Relive Linux history with the ROX desktop.md
@@ -0,0 +1,104 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Relive Linux history with the ROX desktop)
+[#]: via: (https://opensource.com/article/19/12/linux-rox-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Relive Linux history with the ROX desktop
+======
+This article is part of a special series of 24 days of Linux desktops.
+If you're looking for a fun trip back in time, the ROX desktop is well
+worth a go.
+![Person typing on a 1980's computer][1]
+
+The [ROX][2] desktop is no longer being actively developed, but its legacy resounds today, and even when it was active, it was a unique take on what a Linux desktop could be. While other desktops felt roughly similar to old Unix or Windows interfaces, ROX belongs solidly in the BeOS, AmigaOS, and [RISC OS][3] desktop camps.
+
+It focuses on drag-and-drop actions (which makes its accessibility non-optimal for some users), point-and-click actions, pop-up contextual menus, and a unique system of app directories for running local applications with no installation required.
+
+### Installing ROX
+
+Today, ROX is mostly abandoned and left in fragments that the user is left to sort out. Luckily, the puzzle is relatively easy to solve, but don't get confused when you find bits and pieces of the ROX desktop in your distribution's repository—but not _every_ bit of the ROX desktop. The popular parts of ROX—the file manager ([ROX-Filer][4]) and the terminal ([ROXTerm][5])—seem to have endured in most of the popular distribution repositories, and you can install (and use) them as standalone applications. However, to run the ROX desktop, you must also install ROX-Session and the libraries it depends on.
+
+I installed ROX on Slackware 14.2, but it should work on any Linux or BSD system.
+
+First, you must install [ROX-lib2][6] from its repository. True to its philosophy of minimal installs, all you have to do to install ROX-lib2 is download the tarball, [unarchive it][7], and move the **ROX-Lib** directory to **/usr/local/lib**.
+
+Next, you have to install [ROX-Session][8]. This probably needs to be compiled from source code, as it's not likely to be in your software repository. The compile process requires build tools, which ship by default on Slackware but are often omitted in other distributions to save space on the initial download. The names of the packages you must install to build from source code vary depending on your distro, so refer to the documentation for specifics. For example, on Debian-based distributions, you can learn about build requirements in [Debian's wiki][9], and on Fedora-based distributions, refer to [Fedora's docs][10]. Once you have the build tools installed, execute the custom ROX-Session build script:
+
+
+```
+`$ ./AppRun`
+```
+
+This manages its own build and installation and prompts you for root permissions to add itself as an option on your login screen.
+
+If you have not installed ROX-Filer from your software repository, do that before continuing.
+
+Together, these components create a complete ROX desktop. To log into your new desktop, log out of your current desktop session. By default, your session manager (KDM, GDM, LightDM, or XDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+With SDDM:
+
+![][11]
+
+With GDM:
+
+![][12]
+
+### ROX desktop features
+
+The ROX desktop is simple by default, with a single panel at the bottom of the screen and a shortcut icon to your home directory on the desktop. The panel contains shortcuts to common locations. That's all there is to the ROX desktop, at least as it's configured out of the box. If you want a clock or a calendar or a system tray, you need to find applications that provide them.
+
+![Default ROX desktop][13]
+
+There is no taskbar, as such, but when you minimize a window, it becomes a temporary icon on your desktop. You can click the icon to bring its window back to its former size and placement.
+
+The panel can be modified some, as well. You can place different shortcuts into it and even create your own applets.
+
+There's no application menu, either, nor are there shortcuts to applications in a contextual menu. Instead, you can navigate manually to **/usr/share/applications**, or you can add your application directory or directories to the ROX panel.
+
+![ROX desktop][14]
+
+The ROX desktop's workflow concentrates on being mouse-driven, reminiscent of Mac OS 7.5 and 8. With ROX-filer, you can manage permissions, file management, introspection, script launching, background setting, and nearly anything else you can think of, provided that you're patient enough for the point-and-click style of interaction. For power users, this seems slow, but ROX manages to make it relatively painless and very intuitive.
+
+### App directories, AppRun, and AppImage
+
+The ROX desktop has an elegant convention by which a directory containing a script named **AppRun** is executed as if it were an application. This means that in order to make a ROX app, all you have to do is compile code into a directory, place a script called **AppRun** at the root of that directory to execute the binary you've compiled, and then mark the directory executable. ROX-Filer displays a directory configured in the manner you set with a special icon and color. When you click on an app directory, ROX-Filer automatically runs the **AppRun** script inside. It looks and behaves exactly like an application that has been installed, but it's local to the user's home directory and requires no special permissions.
+
+This is a convenience feature, but it's one of those small features that feels great when you use it because it's so easy to implement. It's by no means essential, and it's only a few steps ahead of building an application locally, hiding the directory somewhere out of the way, and drumming up a quick **.desktop** file to act as your launcher. However, the concept of an application directory has been [cited][15] as an inspiration for the [AppImage][16] packaging system.
+
+### Why you should try ROX desktop
+
+Getting ROX set up and usable is somewhat difficult, and it appears to truly be abandoned. However, its legacy lives on in many ways today, and it's a fascinating and fun bit of Linux history. It may not become your primary desktop, but if you're looking for a fun trip back in time, then ROX is well worth a go. Explore it, customize it, and see what clever ideas it contains. There may yet be hidden gems that the open source community can benefit from.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-rox-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/1980s-computer-yearbook.png?itok=eGOYEKK- (Person typing on a 1980's computer)
+[2]: http://rox.sourceforge.net/desktop/
+[3]: https://www.riscosopen.org/content/
+[4]: http://rox.sourceforge.net/desktop/ROX-Filer
+[5]: http://roxterm.sourceforge.net/
+[6]: http://rox.sourceforge.net/desktop/ROX-Lib
+[7]: https://opensource.com/article/17/7/how-unzip-targz-file
+[8]: http://rox.sourceforge.net/desktop/ROX-Session.html
+[9]: https://wiki.debian.org/BuildingTutorial
+[10]: https://docs.pagure.org/docs-fedora/installing-software-from-source.html
+[11]: https://opensource.com/sites/default/files/advent-kdm_0.jpg
+[12]: https://opensource.com/sites/default/files/advent-gdm_1.jpg
+[13]: https://opensource.com/sites/default/files/uploads/advent-rox.jpg (Default ROX desktop)
+[14]: https://opensource.com/sites/default/files/uploads/advent-rox-custom.jpg (ROX desktop)
+[15]: https://github.com/AppImage/AppImageKit/wiki/AppDir
+[16]: https://appimage.org/
diff --git a/sources/tech/20191216 Setting up the sway window manager on Fedora.md b/sources/tech/20191216 Setting up the sway window manager on Fedora.md
new file mode 100644
index 0000000000..67c1e34f4c
--- /dev/null
+++ b/sources/tech/20191216 Setting up the sway window manager on Fedora.md
@@ -0,0 +1,157 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Setting up the sway window manager on Fedora)
+[#]: via: (https://fedoramagazine.org/setting-up-the-sway-window-manager-on-fedora/)
+[#]: author: (George Luiz Maluf https://fedoramagazine.org/author/georgelmaluf/)
+
+Setting up the sway window manager on Fedora
+======
+
+![][1]
+
+Sometimes during a critical activity, working with overlapping windows becomes counterproductive. You might find a tiled window manager like sway to be a good alternative.
+
+Sway is a tiling Wayland compositor. It has the advantage of compatibility with an existing [i3 configuration][2], so you can use it to replace i3 and use Wayland as the display protocol.
+
+### Installing sway
+
+To setup sway, open a new terminal and type the following command
+
+```
+sudo dnf install sway
+```
+
+Once the installation is completed, log out of your user session. At the login screen, select your user account. Before you enter your password, choose _Sway_ from the menu, as shown in the following image.
+
+![][3]
+
+After login, your desktop looks like this:
+
+![][4]
+
+### Configuration
+
+To begin configuration, copy the default config into your user directory. Do that using the following commands.
+
+```
+mkdir -p .config/sway
+cp /etc/sway/config ~/.config/sway/
+```
+
+Sway is highly configurable. It’s suggested you read the project’s [wiki page][5] to fine tune your settings. For example, to change the keyboard layout, open a new terminal and run this command:
+
+```
+$ swaymsg -t get_inputs
+[george@mrwhite ~]$ swaymsg -t get_inputs
+ Input device: VirtualPS/2 VMware VMMouse
+ Type: Mouse
+ Identifier: 2:19:VirtualPS/2_VMware_VMMouse
+ Product ID: 19
+ Vendor ID: 2
+ Libinput Send Events: enabled
+ Input device: VirtualPS/2 VMware VMMouse
+ Type: Mouse
+ Identifier: 2:19:VirtualPS/2_VMware_VMMouse
+ Product ID: 19
+ Vendor ID: 2
+ Libinput Send Events: enabled
+ Input device: AT Translated Set 2 keyboard
+ Type: Keyboard
+ Identifier: 1:1:AT_Translated_Set_2_keyboard
+ Product ID: 1
+ Vendor ID: 1
+ Active Keyboard Layout: Portuguese (Brazil)
+ Libinput Send Events: enabled
+```
+
+Copy the identifier keyboard code. Open your _~/.config/sway/config file_ with your text editor and edit the configuration accordingly:
+
+```
+## Input configuration
+input "1:1:AT_Translated_Set_2_keyboard" {
+ xkb_layout br
+}
+```
+
+Save the settings. To reload the configurations, press **Super+Shift+c**. (Typically the **Super** key is mapped to the logo key on a PC.)
+
+### Waybar
+
+Sway’s default status bar may not have all the functions you want. Fortunately Waybar is a good replacement. To install, run the follow commands. _(Note, however, that COPR is not an official Fedora repository and not supported by the Fedora Project.)_
+
+```
+sudo dnf copr enable alebastr/waybar
+sudo dnf install waybar
+```
+
+Open your _~/.config/sway/config_ file. Edit the bar configuration like this:
+
+```
+bar {
+ swaybar_command waybar
+}
+```
+
+Reload the configuration and you’ll now see the waybar in action, as shown below.
+
+![][6]
+
+To customize the waybar, you can visit this [wiki page][7] for more details and ideas.
+
+### Alacritty
+
+Alacritty is a terminal emulator that uses the GPU for rendering, and a good replacement for _urxvt_. To install run the following lines
+
+```
+sudo dnf copr enable pschyska/alacritty
+sudo dnf install alacritty
+```
+
+To enable it as default terminal emulator edit your _~/.config/sway/config_. Change this line:
+
+```
+set $term urxvt256c-ml
+```
+
+To:
+
+```
+set $term alacritty
+```
+
+Reload your configuration.
+
+When you open a new terminal with **Super+C**, alacritty will be open as seen in the following image:
+
+![][8]
+
+* * *
+
+_Photo by [Ivan Vranić][9] on [Unsplash][10]._
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/setting-up-the-sway-window-manager-on-fedora/
+
+作者：[George Luiz Maluf][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/georgelmaluf/
+[b]: https://github.com/lujun9972
+[1]: https://fedoramagazine.org/wp-content/uploads/2019/12/sway-816x345.jpg
+[2]: https://fedoramagazine.org/getting-started-i3-window-manager/
+[3]: https://fedoramagazine.org/wp-content/uploads/2019/11/sway_login_menu-1024x522.png
+[4]: https://fedoramagazine.org/wp-content/uploads/2019/11/sway_desktop_default-1024x522.png
+[5]: https://github.com/swaywm/sway/wiki
+[6]: https://fedoramagazine.org/wp-content/uploads/2019/11/sway_waybar_default-1024x522.png
+[7]: https://github.com/Alexays/Waybar/wiki/Configuration
+[8]: https://fedoramagazine.org/wp-content/uploads/2019/11/sway_alacritty-1024x522.png
+[9]: https://unsplash.com/@hvranic?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
+[10]: https://unsplash.com/s/photos/sway?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
diff --git a/sources/tech/20191217 App Highlight- Open Source Disk Partitioning Tool GParted.md b/sources/tech/20191217 App Highlight- Open Source Disk Partitioning Tool GParted.md
new file mode 100644
index 0000000000..6c78a12ecb
--- /dev/null
+++ b/sources/tech/20191217 App Highlight- Open Source Disk Partitioning Tool GParted.md
@@ -0,0 +1,116 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (App Highlight: Open Source Disk Partitioning Tool GParted)
+[#]: via: (https://itsfoss.com/gparted/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+App Highlight: Open Source Disk Partitioning Tool GParted
+======
+
+_**Brief: GParted is an incredibly popular and free partition editor available for Linux distros. Here, we take a look at what it offers in brief.**_
+
+### GParted: A Free & Open-Source GUI-based Partition Manager
+
+![][1]
+
+GParted is undoubtedly one of the [best partition managers for Linux][2] out there. The user interface is very simple and gets the job done.
+
+In some cases, you end up using [GParted][3] to fix or format your USB drive as well. I had a [USB disk which I couldn’t format in Ubuntu][4] using the “Disks” app – this is where GParted came to the rescue.
+
+So, it is a quite useful tool with a lot of good features. Let me highlight them for you.
+
+Warning!
+
+Playing with disk partitioning is a risky task. Don’t do it unless it’s absolutely necessary. Or else, you might just end up wiping the entire disk.
+
+### Features of GParted
+
+You can do a lot of things with GParted, ranging from a simple format task to important partitioning tasks. I’ll highlight the key features with some screenshots to help you know more about it before installing it.
+
+#### Create partition tables
+
+You can create a new partition table for your new disks or erase the content of your existing disk to modify the partition table.
+
+![][5]
+
+You will be able to select msdos, gpt, atari, and a lot more types of partition tables.
+
+#### Create, move, label, delete & modify partitions
+
+You can easily create, label, delete or modify the partitions with a bunch of options available within GParted.
+
+![][6]
+
+Of course, you will have to be careful about what you want to do.
+
+The good thing is that GParted makes sure that you do not directly apply any changes – it queues up your selected operations/tasks and asks for another final confirmation before you hit it.
+
+The tick mark symbol ✓on the top allows you to confirm the changes and then only your changes take into effect.
+
+Here’s another screenshot for the options you have available for the partitions:
+
+![][7]
+
+#### Attempt data rescue
+
+Apart from editing partitions, you can also try to [recover your lost data in Linux][8] using the “**Attempt Data Rescue**” feature as shown in the screenshot below.
+
+![][9]
+
+It is worth noting that you do not have this feature installed by default – you only see the option visible. So, for the data recovery feature to work, you have to install gpart separately using the following command (on Ubuntu/Debian-based distributions):
+
+```
+sudo apt install gpart
+```
+
+In addition to all the key features, it supports a wide range of storage devices and filesystems. You can learn more about it from the [list of features][10] on their official website.
+
+### Installing GParted on Ubuntu and other Linux distributions
+
+You might have GParted pre-installed. So, make sure to verify that. If you do not have it installed, you can head into the software center to get it installed.
+
+In case you want to use the terminal, simply type in the following command:
+
+```
+sudo apt install gparted
+```
+
+As I mentioned above, if you want the data recovery option, you should install gpart package in addition to gparted package.
+
+If you’re using any other Linux distribution, you can either find it in the respective software manager or simply check out the [official download instructions][11].
+
+[Download GParted][11]
+
+**Wrapping Up**
+
+GParted is a very useful and important tool when it comes to dealing with disk management and partitions. However, you will have to be careful while using it for the obvious reasons.
+
+Have you tried GParted? Which other partitioning tool you use on Linux? Feel free to share your experiences in the comments below.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/gparted/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/gparted-screenshot.png?ssl=1
+[2]: https://itsfoss.com/partition-managers-linux/
+[3]: https://gparted.org/
+[4]: https://itsfoss.com/format-usb-drive-sd-card-ubuntu/
+[5]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/gparted-create-partition-table.png?ssl=1
+[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/gparted-modify-partitions.png?ssl=1
+[7]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/gparted-partition-options.png?ssl=1
+[8]: https://itsfoss.com/recover-deleted-files-linux/
+[9]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/gparted-attempt-data-rescue-feature.png?ssl=1
+[10]: https://gparted.org/features.php
+[11]: https://gparted.org/download.php
diff --git a/sources/tech/20191218 Emacs for Vim users- Getting started with the Spacemacs text editor.md b/sources/tech/20191218 Emacs for Vim users- Getting started with the Spacemacs text editor.md
new file mode 100644
index 0000000000..a5782451e1
--- /dev/null
+++ b/sources/tech/20191218 Emacs for Vim users- Getting started with the Spacemacs text editor.md
@@ -0,0 +1,113 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Emacs for Vim users: Getting started with the Spacemacs text editor)
+[#]: via: (https://opensource.com/article/19/12/spacemacs)
+[#]: author: (Kevin Sonney https://opensource.com/users/ksonney)
+
+Emacs for Vim users: Getting started with the Spacemacs text editor
+======
+Spacemacs offers all the power of Emacs combined with the keystroke
+commands and functionality you are used to in Vim.
+![Hands programming][1]
+
+I use [Vim][2] a lot. I'm a site reliability engineer (SRE), and Vim is the one thing I know I can access on every machine in our fleet. I also like [Emacs][3], with its wide variety of useful packages, ease of extending, and its many built-in tools. Because they each have their own set of commands, I have to actively switch codes in my head (usually after typing **:wq** in Emacs or trying to **C+X** in Vim). The [Evil][4] package for Emacs helps quite a bit by making Emacs behave more like Vim, but there is some effort required to set it up the first time.
+
+### Enter Spacemacs
+
+![Spacemacs splash screen][5]
+
+[Spacemacs][6] is a set of configurations for Emacs that combines an easy setup, Evil, and a system to manage and set up additional Emacs packages with pre-built configurations to make them easier to use out of the box.
+
+### Installation and setup
+
+As I mentioned above, Spacemacs is easy to install. No, really: it takes just one command:
+
+
+```
+`git clone https://github.com/syl20bnr/spacemacs ~/.emacs.d`
+```
+
+Then just start Emacs. It will prompt you through the basic configuration options and generate a **.spacemacs** configuration file. The defaults are as safe as can be: Vim keybindings, Spacemacs' recommended packages, and the Helm search engine. When the configuration completes, you will see a help screen with some basic information and commands.
+
+![Spacemacs help screen][7]
+
+Now Spacemacs is set up and ready to go and will behave like Vim. You can start right away by entering **:e </path/to/file>** to open and edit a file and using good old **:wq** to save (among other commands). As a bonus, if you are a seasoned Emacs user, many of the commands you are used to are still there.
+
+### Using Spacemacs
+
+On the main splash screen, you'll notice a lot of information. There are buttons to update Spacemacs and the packages, access different forms of documentation, and open recently edited files.
+
+Whenever you're not in insert mode, you can press the **Space Bar** to bring up a menu of other available options. The default options include access to the Helm search engine and the basic functions for opening and editing files. As you add packages, they will also show up in the menu. In most special screens (i.e., those that are not a document you are editing), the **q** key will exit the screen.
+
+### Configuring Spacemacs
+
+Before getting into Spacemacs' configuration, you need to understand **layers**. Layers are self-contained configuration files that load on top of one another. A layer is comprised of the instructions to download and install the package and any dependencies, as well as the basic configuration and key mappings for the package.
+
+Spacemacs has quite a few [layers available][8], and more are being added all the time. You can find the complete list in the **~/.emacs.d/layers** directory tree. They are organized by type; to use one, just add it in the main **.spacemacs** configuration file to the **dotspacemacs-configuration-layers** list.
+
+I generally enable the Git, Version-Control, Markdown, and Colors (theme support) layers. If you are familiar with configuring Emacs, you can also add custom configurations in [Lisp][9] to the **dotspacemacs/user-config** section.
+
+You can also enable a Nyan Cat progress bar by adding the following line in your layers list:
+
+
+```
+`(colors :variables colors-enable-nyan-cat-progress-bar t)`
+```
+
+
+
+![Nyan Cat progress bar in Spacemacs][10]
+
+### Using Org mode in Spacemacs
+
+One of my other favorite layers is [Org mode][11], probably one of the most popular notes, to-do, and project management applications in the open source world.
+
+To install Org, just open up the **.spacemacs** file and uncomment the line for **org** under **dotspacemacs-configuration-layers**.
+
+![Installing Org mode in Spacemacs][12]
+
+Exit and restart Emacs, and it will download the Org packages and set them up. Type **Space Bar+a**, and you see a new menu item for Org with the hotkey **o**, and the common Org functions—agenda, to-do list, etc.—are under that menu. They are blank until you configure the default Org files. The easiest way to do that is with the built-in Emacs configuration tool, which you can access by typing **Space Bar+?** and searching for **Customize**. When the Customize screen opens, search for **org-agenda-files**. Add a file or two to the list (I used **~/todo.org** and **~/notes.org**), click Apply and Save, then exit Customize.
+
+![Emacs Customize tool in Spacemacs][13]
+
+Next, create a file so that Org can read them into the agenda and to-do list. Even if the file is blank, that's OK—it just has to exist. Since I added two files—todo.org and notes.org—to my configuration, I can type **:e todo.org** and **:e notes.org** to open both, and then **:w** to save the blank files.
+
+Next, enter the Org agenda with **Space Bar+a+o+a** or the Org to-do list with **Space Bar+a+o+t**. If you have added actionable items or scheduled events to the notes or to-do files, you will see them now. You can find out more about Org's structure and syntax in _[Get started with Org mode without Emacs][14]_ or on the [Org mode][11] website.
+
+![Spacemacs todo.org and the Org todo agenda][15]
+
+Spacemacs offers all the power of Emacs combined with the keystroke commands and functionality you are used to with Vim. Give it a try, and please let me know what you think in the comments.
+
+This is a short list of my favorite graphical text editors for Linux that can be classified as IDE...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/spacemacs
+
+作者：[Kevin Sonney][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/ksonney
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/programming-code-keyboard-laptop.png?itok=pGfEfu2S (Hands programming)
+[2]: https://www.vim.org/
+[3]: https://www.gnu.org/software/emacs
+[4]: https://www.emacswiki.org/emacs/Evil
+[5]: https://opensource.com/sites/default/files/uploads/spacemacs_spash.png (Spacemacs splash screen)
+[6]: https://www.spacemacs.org/
+[7]: https://opensource.com/sites/default/files/uploads/spacemacs_help.png (Spacemacs help screen)
+[8]: https://www.spacemacs.org/layers/LAYERS.html
+[9]: https://en.wikipedia.org/wiki/Lisp_(programming_language)
+[10]: https://opensource.com/sites/default/files/uploads/nyan-cat-progress.png (Nyan Cat progress bar in Spacemacs)
+[11]: https://orgmode.org
+[12]: https://opensource.com/sites/default/files/uploads/spacemacs_org_change.png (Installing Org mode in Spacemacs)
+[13]: https://opensource.com/sites/default/files/uploads/emacs_customize.png (Emacs Customize tool in Spacemacs)
+[14]: https://opensource.com/article/19/1/productivity-tool-org-mode
+[15]: https://opensource.com/sites/default/files/uploads/spacemacs_org.png (Spacemacs todo.org and the Org todo agenda)
diff --git a/sources/tech/20191218 How to tell if you-re using a bash builtin in Linux.md b/sources/tech/20191218 How to tell if you-re using a bash builtin in Linux.md
new file mode 100644
index 0000000000..466dde98c7
--- /dev/null
+++ b/sources/tech/20191218 How to tell if you-re using a bash builtin in Linux.md
@@ -0,0 +1,153 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to tell if you’re using a bash builtin in Linux)
+[#]: via: (https://www.networkworld.com/article/3505818/how-to-tell-if-youre-using-a-bash-builtin-in-linux.html)
+[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
+
+How to tell if you’re using a bash builtin in Linux
+======
+A built-in is a Linux command that's part of whatever shell you're using. Can you tell what commands are built-ins and which are not?
+Guenter Guni / Getty Images
+
+If you’re not sure if you’re running a Linux command or you’re using a bash builtin, don’t stress, it isn’t all that obvious. In fact, you can get very used to commands like **cd** without realizing that they’re part of your shell, unlike commands like **date** and **whoami** that invoke executables (**/bin/date** and **/usr/bin/whoami**).
+
+Builtins in general are commands that are built into shell interpreters, and bash is especially rich in them, which is a good thing because built-ins by their very nature run a bit faster than commands which have to be loaded into memory when you call them into play.
+
+[[Get regularly scheduled insights by signing up for Network World newsletters.]][1]
+
+In other words, some commands are built into the shell because they pretty much have to be. After all, a command like **cd** needs to change the shell’s view of the world – or at least its perspective on the file system. Others provide the shell with its special ability to loop and evaluate data – like **case**, **for** and **while** commands. In short, these commands make the shell what it is for all of its devoted users. Still others just make commands run a little faster.
+
+[][2]
+
+BrandPost Sponsored by HPE
+
+[Take the Intelligent Route with Consumption-Based Storage][2]
+
+Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
+
+To get a list of bash built-ins, all you have to type is “help”.
+
+```
+$ help
+GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu)
+These shell commands are defined internally. Type `help' to see this list.
+Type `help name' to find out more about the function `name'.
+Use `info bash' to find out more about the shell in general.
+Use `man -k' or `info' to find out more about commands not in this list.
+
+A star (*) next to a name means that the command is disabled.
+
+ job_spec [&] history [-c] [-d offset] [n] or history -an>
+ (( expression )) if COMMANDS; then COMMANDS; [ elif COMMANDS>
+ . filename [arguments] jobs [-lnprs] [jobspec ...] or jobs -x comm>
+ : kill [-s sigspec | -n signum | -sigspec] pi>
+ [ arg... ] let arg [arg ...]
+ [[ expression ]] local [option] name[=value] ...
+ alias [-p] [name[=value] ... ] logout [n]
+ bg [job_spec ...] mapfile [-d delim] [-n count] [-O origin] [>
+ bind [-lpsvPSVX] [-m keymap] [-f filename] [> popd [-n] [+N | -N]
+ break [n] printf [-v var] format [arguments]
+ builtin [shell-builtin [arg ...]] pushd [-n] [+N | -N | dir]
+ caller [expr] pwd [-LP]
+ case WORD in [PATTERN [| PATTERN]...) COMMAN> read [-ers] [-a array] [-d delim] [-i text]>
+ cd [-L|[-P [-e]] [-@]] [dir] readarray [-d delim] [-n count] [-O origin]>
+ command [-pVv] command [arg ...] readonly [-aAf] [name[=value] ...] or reado>
+ compgen [-abcdefgjksuv] [-o option] [-A acti> return [n]
+ complete [-abcdefgjksuv] [-pr] [-DEI] [-o op> select NAME [in WORDS ... ;] do COMMANDS; d>
+ compopt [-o|+o option] [-DEI] [name ...] set [-abefhkmnptuvxBCHP] [-o option-name] [>
+ continue [n] shift [n]
+ coproc [NAME] command [redirections] shopt [-pqsu] [-o] [optname ...]
+ declare [-aAfFgilnrtux] [-p] [name[=value] .> source filename [arguments]
+ dirs [-clpv] [+N] [-N] suspend [-f]
+ disown [-h] [-ar] [jobspec ... | pid ...] test [expr]
+ echo [-neE] [arg ...] time [-p] pipeline
+ enable [-a] [-dnps] [-f filename] [name ...> times
+ eval [arg ...] trap [-lp] [[arg] signal_spec ...]
+ exec [-cl] [-a name] [command [arguments ...> true
+ exit [n] type [-afptP] name [name ...]
+ export [-fn] [name[=value] ...] or export -> typeset [-aAfFgilnrtux] [-p] name[=value] .>
+ false ulimit [-SHabcdefiklmnpqrstuvxPT] [limit]
+ fc [-e ename] [-lnr] [first] [last] or fc -s> umask [-p] [-S] [mode]
+ fg [job_spec] unalias [-a] name [name ...]
+ for NAME [in WORDS ... ] ; do COMMANDS; don> unset [-f] [-v] [-n] [name ...]
+ for (( exp1; exp2; exp3 )); do COMMANDS; don> until COMMANDS; do COMMANDS; done
+ function name { COMMANDS ; } or name () { CO> variables - Names and meanings of some shel>
+ getopts optstring name [arg] wait [-fn] [id ...]
+ hash [-lr] [-p pathname] [-dt] [name ...] while COMMANDS; do COMMANDS; done
+ help [-dms] [pattern ...] { COMMANDS ; }
+```
+
+You might notice that some of these built-ins (e.g., **echo** and **kill**) also exist as executables.
+
+```
+$ ls -l /bin/echo /bin/kill
+-rwxr-xr-x 1 root root 39256 Sep 5 06:38 /bin/echo
+-rwxr-xr-x 1 root root 30952 Aug 8 12:46 /bin/kill
+```
+
+One quick way to determine whether the command you are using is a bash built-in or not is to use the command “command”. Yes, the command is called “command”. Try it with a **-V** (capital V) option like this:
+
+```
+$ command -V command
+command is a shell builtin
+$ command -V echo
+echo is a shell builtin
+$ command -V date
+date is hashed (/bin/date)
+```
+
+When you see a “command is hashed” message like the one above, that means that the command has been put into a hash table for quicker lookup.
+
+### **Looking for help in other shells**
+
+If you switch shells and try running “help”, you’ll notice that some support this command and others do not. You can run a command like this in bash to see what each of the shells on your system will tell you:
+
+```
+for shell in `ls /bin/*sh`
+do
+ echo $shell
+ $shell -c "help"
+ echo ===============
+done
+```
+
+This loop will try running the help command in each of the shells in /bin. The $shell -c (e.g., zsh -c) syntax will run just the single help command in that shell and then exit.
+
+### How to tell what shell you're currently using
+
+If you switch shells you can’t depend on $SHELL to tell you what shell you’re currently using because $SHELL is just an environment variable that is set when you log in and doesn't necessarily reflect your current shell. Try **ps -p $$** instead as shown in these examples:
+
+```
+$ ps -p $$
+ PID TTY TIME CMD
+18340 pts/0 00:00:00 bash <==
+$ /bin/dash
+$ ps -p $$
+ PID TTY TIME CMD
+19517 pts/0 00:00:00 dash <==
+```
+
+Built-ins are extremely useful and give each shell a lot of its character. If you use some particular shell all of the time, it’s easy to lose track of which commands are part of your shell and which are not. Differentiating a shell built-in from a Linux executable requires only a little extra effort.
+
+Join the Network World communities on [Facebook][3] and [LinkedIn][4] to comment on topics that are top of mind.
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3505818/how-to-tell-if-youre-using-a-bash-builtin-in-linux.html
+
+作者：[Sandra Henry-Stocker][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
+[b]: https://github.com/lujun9972
+[1]: https://www.networkworld.com/newsletters/signup.html
+[2]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
+[3]: https://www.facebook.com/NetworkWorld/
+[4]: https://www.linkedin.com/company/network-world
diff --git a/sources/tech/20191218 Introduction to automation with Bash scripts.md b/sources/tech/20191218 Introduction to automation with Bash scripts.md
new file mode 100644
index 0000000000..f73c6e36c4
--- /dev/null
+++ b/sources/tech/20191218 Introduction to automation with Bash scripts.md
@@ -0,0 +1,164 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Introduction to automation with Bash scripts)
+[#]: via: (https://opensource.com/article/19/12/automation-bash-scripts)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+Introduction to automation with Bash scripts
+======
+In the first article in this four-part series, learn how to create a
+simple shell script and why they are the best way to automate tasks.
+![Person using a laptop][1]
+
+Sysadmins, those of us who run and manage Linux computers most closely, have direct access to tools that help us work more efficiently. To help you use these tools to their maximum benefit to make your life easier, this series of articles explores using automation in the form of Bash shell scripts. It covers:
+
+ * The advantages of automation with Bash shell scripts
+ * Why using shell scripts is a better choice for sysadmins than compiled languages like C or C++
+ * Creating a set of requirements for new scripts
+ * Creating simple Bash shell scripts from command-line interface (CLI) programs
+ * Enhancing security through using the user ID (UID) running the script
+ * Using logical comparison tools to provide execution flow control for command-line programs and scripts
+ * Using command-line options to control script functionality
+ * Creating Bash functions that can be called from one or more locations within a script
+ * Why and how to license your code as open source
+ * Creating and implementing a simple test plan
+
+
+
+I previously wrote a series of articles about Bash commands and syntax and creating Bash programs at the command line, which you can find in the references section at the end of this article. But this series of four articles is as much about creating scripts (and some techniques that I find useful) as it is about Bash commands and syntax.
+
+### Why I use shell scripts
+
+In Chapter 9 of [_The Linux Philosophy for Sysadmins_][2], I write:
+
+> "A sysadmin is most productive when thinking—thinking about how to solve existing problems and about how to avoid future problems; thinking about how to monitor Linux computers in order to find clues that anticipate and foreshadow those future problems; thinking about how to make [their] job more efficient; thinking about how to automate all of those tasks that need to be performed whether every day or once a year.
+>
+> "Sysadmins are next most productive when creating the shell programs that automate the solutions that they have conceived while appearing to be unproductive. The more automation we have in place, the more time we have available to fix real problems when they occur and to contemplate how to automate even more than we already have."
+
+This first article explores why shell scripts are an important tool for the sysadmin and the basics of creating a very simple Bash script.
+
+### Why automate?
+
+Have you ever performed a long and complex task at the command line and thought, "Glad that's done. Now I never have to worry about it again!"? I have—frequently. I ultimately figured out that almost everything that I ever need to do on a computer (whether mine or one that belongs to an employer or a consulting customer) will need to be done again sometime in the future.
+
+Of course, I always think that I will remember how I did the task. But, often, the next time is far enough into the future that I forget that I have _ever_ done it, let alone _how_ to do it. I started writing down the steps required for some tasks on bits of paper, then thought, "How stupid of me!" So I transferred those scribbles to a simple notepad application on my computer, until one day, I thought again, "How stupid of me!" If I am going to store this data on my computer, I might as well create a shell script and store it in a standard location, like **/usr/local/bin** or **~/bin**, so I can just type the name of the shell program and let it do all the tasks I used to do manually.
+
+For me, automation also means that I don't have to remember or recreate the details of how I performed the task in order to do it again. It takes time to remember how to do things and time to type in all the commands. This can become a significant time sink for tasks that require typing large numbers of long commands. Automating tasks by creating shell scripts reduces the typing necessary to perform routine tasks.
+
+### Shell scripts
+
+Writing shell programs—also known as scripts—is the best strategy for leveraging my time. Once I write a shell program, I can rerun it as many times as I need to. I can also update my shell scripts to compensate for changes from one release of Linux to the next, installing new hardware and software, changing what I want or need to accomplish with the script, adding new functions, removing functions that are no longer needed, and fixing the not-so-rare bugs in my scripts. These kinds of changes are just part of the maintenance cycle for any type of code.
+
+Every task performed via the keyboard in a terminal session by entering and executing shell commands can and should be automated. Sysadmins should automate everything we are asked to do or decide needs to be done. Many times, doing the automation upfront saves me time the first time.
+
+One Bash script can contain anywhere from a few commands to many thousands. I have written Bash scripts with only one or two commands, and I have written a script with over 2,700 lines, more than half of which are comments.
+
+### Getting started
+
+Here's a trivial example of a shell script and how to create it. In my earlier series on Bash command-line programming, I used the example from every book on programming I have ever read: "Hello world." From the command line, it looks like this:
+
+
+```
+[student@testvm1 ~]$ echo "Hello world"
+Hello world
+```
+
+By definition, a program or shell script is a sequence of instructions for the computer to execute. But typing them into the command line every time is quite tedious, especially when the programs are long and complex. Storing them in a file that can be executed with a single command saves time and reduces the possibility for errors to creep in.
+
+I recommend trying the following examples as a non-root user on a test system or virtual machine (VM). Although the examples are harmless, mistakes do happen, and being safe is always wise.
+
+The first task is to create a file to contain your program. Use the **touch** command to create the empty file, **hello**, then make it executable:
+
+
+```
+[student@testvm1 ~]$ touch hello
+[student@testvm1 ~]$ chmod 774 hello
+```
+
+Now, use your favorite editor to add the following line to the file:
+
+
+```
+`echo "Hello world"`
+```
+
+Save the file and run it from the command line. You can use a separate shell session to execute the scripts in this series:
+
+
+```
+[student@testvm1 ~]$ ./hello
+Hello world!
+```
+
+This is the simplest Bash program you may ever create—a single statement in a file. For this exercise, your complete shell script will be built around this simple Bash statement. The function of the program is irrelevant for this purpose, and this simple statement allows you to build a program structure—a template for other programs—without being concerned about the logic of a functional purpose. You can concentrate on the basic program structure and creating your template in a very simple way, and you can create and test the template itself rather than a complex functional program.
+
+### Shebang
+
+The single statement works fine as long as you use Bash or a shell compatible with the commands used in the script. If no shell is specified in the script, the default shell will be used to execute the script commands.
+
+The next task is to ensure that the script will run using the Bash shell, even if another shell is the default. This is accomplished with the shebang line. Shebang is the geeky way to describe the **#!** characters that explicitly specify which shell to use when running the script. In this case, that is Bash, but it could be any other shell. If the specified shell is not installed, the script will not run.
+
+Add the shebang line as the first line of the script, so now it looks like this:
+
+
+```
+#!/usr/bin/bash
+echo "Hello world!"
+```
+
+Run the script again—you should see no difference in the result. If you have other shells installed (such as ksh, csh, tcsh, zsh, etc.), start one and run the script again.
+
+### Scripts vs. compiled programs
+
+When writing programs to automate—well, everything—sysadmins should always use shell scripts. Because shell scripts are stored in ASCII text format, they can be viewed and modified by humans just as easily as they can by computers. You can examine a shell program and see exactly what it does and whether there are any obvious errors in the syntax or logic. This is a powerful example of what it means to be _open_.
+
+I know some developers consider shell scripts something less than "true" programming. This marginalization of shell scripts and those who write them seems to be predicated on the idea that the only "true" programming language is one that must be compiled from source code to produce executable code. I can tell you from experience that this is categorically untrue.
+
+I have used many languages, including BASIC, C, C++, Pascal, Perl, Tcl/Expect, REXX (and some of its variations, including Object REXX), many shell languages (including Korn, csh and Bash), and even some assembly language. Every computer language ever devised has had one purpose: to allow humans to tell computers what to do. When you write a program, regardless of the language you choose, you are giving the computer instructions to perform specific tasks in a specific sequence.
+
+Scripts can be written and tested far more quickly than compiled languages. Programs usually must be written quickly to meet time constraints imposed by circumstances or the pointy-haired boss. Most scripts that sysadmins write are to fix a problem, to clean up the aftermath of a problem, or to deliver a program that must be operational long before a compiled program could be written and tested.
+
+Writing a program quickly requires shell programming because it enables a quick response to the needs of the customer—whether that is you or someone else. If there are problems with the logic or bugs in the code, they can be corrected and retested almost immediately. If the original set of requirements is flawed or incomplete, shell scripts can be altered very quickly to meet the new requirements. In general, the need for speed of development in the sysadmin's job overrides the need to make the program run as fast as possible or to use as little as possible in the way of system resources like RAM.
+
+Most things sysadmins do take longer to figure out how to do than to execute. Thus, it might seem counterproductive to create shell scripts for everything you do. It takes some time to write the scripts and make them into tools that produce reproducible results and can be used as many times as necessary. The time savings come every time you can run the script without having to figure out (again) how to do the task.
+
+### Final thoughts
+
+This article didn't get very far with creating a shell script, but it did create a very small one. It also explored the reasons for creating shell scripts and why they are the most efficient option for the system administrator (rather than compiled programs).
+
+In the next article, you will begin creating a Bash script template that can be used as a starting point for other Bash scripts. The template will ultimately contain a Help facility, a GNU licensing statement, a number of simple functions, and some logic to deal with those options, as well as others that might be needed for the scripts that will be based on this template.
+
+### Resources
+
+ * [How to program with Bash: Syntax and tools][3]
+ * [How to program with Bash: Logical operators and shell expansions][4]
+ * [How to program with Bash: Loops][5]
+
+
+
+* * *
+
+_This series of articles is partially based on Volume 2, Chapter 10 of David Both's three-part Linux self-study course, [Using and Administering Linux—Zero to SysAdmin][6]._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/automation-bash-scripts
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/laptop_screen_desk_work_chat_text.png?itok=UXqIDRDD (Person using a laptop)
+[2]: http://www.both.org/?page_id=903
+[3]: https://opensource.com/article/19/10/programming-bash-syntax-tools
+[4]: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
+[5]: https://opensource.com/article/19/10/programming-bash-loops
+[6]: http://www.both.org/?page_id=1183
diff --git a/sources/tech/20191218 Linux desktops for minimalists- Getting started with LXQt and LXDE.md b/sources/tech/20191218 Linux desktops for minimalists- Getting started with LXQt and LXDE.md
new file mode 100644
index 0000000000..4d12d6c268
--- /dev/null
+++ b/sources/tech/20191218 Linux desktops for minimalists- Getting started with LXQt and LXDE.md
@@ -0,0 +1,72 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Linux desktops for minimalists: Getting started with LXQt and LXDE)
+[#]: via: (https://opensource.com/article/19/12/lxqt-lxde-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Linux desktops for minimalists: Getting started with LXQt and LXDE
+======
+This article is part of a special series of 24 days of Linux desktops.
+Both LXDE and LXQt aim to provide a lightweight desktop for users who
+either need it or just prefer it, with minimal setup or configuration
+required.
+![Penguins walking on the beach ][1]
+
+Preserving and resurrecting old computers is a popular part of the Linux hacker's ethos, and one way to help make that possible is with a desktop environment that doesn't use up scarce system resources. After all, the fact that a current version of Linux can run effectively on a computer over 15 years old is quite a feat, but it doesn't make the CPU and RAM any better than the day they were slotted in. There are extremely light desktops available, but there's usually a catch: the user must assemble the parts. Fortunately, a number of lightweight desktops have appeared over the years in an attempt to provide a fast and light desktop with no setup required.
+
+Two early implementations of this idea were [LXDE][2] and [Razor-qt][3], the former based on GTK (the libraries used by GNOME) and the latter based on Qt (the libraries used by KDE). Coincidentally, the lead maintainer of LXDE discovered [the bliss that is Qt development][4] and decided to port (just as a side project!) the entire desktop to Qt. LXDE, the Qt port of it, and the Razor-qt project were combined to form [LXQt][5], although today, LXDE and LXQt coexist as separate projects.
+
+Whether you use LXDE or LXQt, their goals are the same: to provide a lightweight desktop for users who either need it or just prefer it, with minimal setup or configuration required. These are drop-in desktops for any Linux or BSD system, whether it's 15 years old, or a new Raspberry Pi, or a hefty workstation that was just assembled. I used LXQt for this article, but everything apart from the GUI toolkit and some application names applies equally to LXQt and LXDE.
+
+![LXQt on CentOS][6]
+
+You may find LXQt or LXDE included your distribution's software repository, or you can download and install a distribution that ships LXQt or LXDE as a default desktop. Before you do, though, be aware that an LX* desktop is meant to provide a full desktop experience, so many applications are installed along with the desktop. If you're already running another desktop, you may find yourself with redundant applications (two PDF readers, two media players, two file managers, and so on). If you just want to try the LXQt or LXDE desktop, consider using a desktop virtualization application, such as [GNOME Boxes][7].
+
+After installing, log out of your current desktop session so you can log into your new desktop. By default, your session manager (KDM, GDM, or LightDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+With GDM:
+
+![][8]
+
+With SDDM:
+
+![][9]
+
+### LXQt and LXDE desktop tour
+
+The desktop layout has a classic look that's familiar to anyone who's used KDE's Plasma desktop or, realistically, any computer within the past two decades. There's an application menu in the lower-left corner, a taskbar for pinned and active applications, and a system tray in the lower-right corner. Because this is a full desktop environment, a few lightweight but robust applications are included. There's a text editor, an excellent file manager called PCManFM on LXDE and PCManFM-Qt on LXQt, configuration panels, a terminal, theme settings, and so on.
+
+![LXDE desktop on Fedora][10]
+
+The goal, aside from being light on resources, is to be intuitive, and these desktops excel at that. This isn't the place to look for an innovative new desktop design. The LXDE and LXQt desktops feel like they've been around forever, gliding through user actions with ease, finding just the right balance between explanatory prompts and minimal design. All the default settings are sensible, and 90% of what most users need to do on a desktop is covered (I'm reserving a conservative 10% for unique personal tastes that nobody expects any desktop to guess).
+
+### To LXDE or to LXQt
+
+Linux power users know GTK from Qt and sometimes even _care_ about which one they use, but it seems everyone admits it's down to personal taste and, in the end, doesn't actually matter. If you have no preference between GTK and Qt, then whether you use LXDE or LXQt may as well be a flip of a coin. They each have the same admirable goal: to provide a full desktop experience to any Linux computer that needs one, regardless of processor power or amount of RAM. If you're a fan of simplicity, then both desktops will appeal to you, and you're likely to settle into the defaults without spending hours customizing or rearranging anything at all. Sometimes it's refreshing to not care about the details and get straight to work. LXDE and LXQt are determined to bring that convenience to you, so give one a try.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/lxqt-lxde-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/community-penguins-osdc-lead.png?itok=BmqsAF4A (Penguins walking on the beach )
+[2]: http://lxde.org
+[3]: https://web.archive.org/web/20160220061334/http://razor-qt.org/
+[4]: https://opensource.com/article/17/4/pyqt-versus-wxpython
+[5]: http://lxqt.org
+[6]: https://opensource.com/sites/default/files/uploads/advent-lxqt-file.jpg (LXQt on CentOS)
+[7]: https://opensource.com/article/19/5/getting-started-gnome-boxes-virtualization
+[8]: https://opensource.com/sites/default/files/advent-gdm_1.jpg
+[9]: https://opensource.com/sites/default/files/advent-kdm_0.jpg
+[10]: https://opensource.com/sites/default/files/uploads/advent-lxde.jpg (LXDE desktop on Fedora)
diff --git a/sources/tech/20191218 Make sysadmin work on Fedora easier with screen.md b/sources/tech/20191218 Make sysadmin work on Fedora easier with screen.md
new file mode 100644
index 0000000000..1523293a7d
--- /dev/null
+++ b/sources/tech/20191218 Make sysadmin work on Fedora easier with screen.md
@@ -0,0 +1,165 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Make sysadmin work on Fedora easier with screen)
+[#]: via: (https://fedoramagazine.org/make-sysadmin-work-on-fedora-easier-with-screen/)
+[#]: author: (Carmine Zaccagnino https://fedoramagazine.org/author/carzacc/)
+
+Make sysadmin work on Fedora easier with screen
+======
+
+![][1]
+
+When you manage a Linux instance, you’ll find that your job is made much easier by the many tools designed specifically to deal with something specific within the system. For example, if you need to install packages, you have easy-to-use package managers that make that a breeze. If you need to create, resize or delete filesystems, you can do so using tools that are built to be used by humans. The same goes for managing services and browsing logs with [systemd][2] using the _systemctl_ and _journalctl_ commands respectively. The _screen_ tool is another such example.
+
+You can run all of those tools directly at the command line interface. But if you’re connecting to a server remotely using SSH, sometimes you need another layer between you and the operating system so the command you’re running doesn’t stop if your remote connection terminates. Sysadmins do this to prevent sudden termination in case of a connection issue, but also on purpose to run a command that needs to keep running indefinitely in the background. Enter the _screen_ utility.
+
+### Introducing screen
+
+The _screen_ tool allows you to have multiple sessions (called _screens_) that are independent from each other and that you can name, leave and join as you desire. It’s multi-tasking for the remote CLI. You can get started with it simply by running this command:
+
+```
+$ screen
+```
+
+The command creates a screen and connect you to it: your current session is now a screen. You can run any command that does something and doesn’t automatically terminate after a few seconds. For example, you might call a web app executable or a game server. Then press **Ctrl+A** and, right after that, the **D** key and you will _detach_ from the screen, leaving it running in the background.
+
+The **Ctrl+A** combination, given that it is part of every _screen_ command, is often shortened in documentation to **C-a**. Then the _detach_ command used earlier can be described simply as **C-a d**.
+
+#### Getting in and out of sessions
+
+If you want to connect to that screen again, run _screen -r_ and you will _attach_ to that screen. Just running **screen** will create a new screen, and subsequent _screen -r_ commands will print out something like this:
+
+```
+There are several suitable screens on:
+ 5589.pts-0.hostname (Detached)
+ 5536.pts-0.hostname (Detached)
+ Type "screen [-d] -r [pid.]tty.host" to resume one of them.
+```
+
+You can then choose whether to resume the first or the second screen you created by running either one of these commands:
+
+```
+$ screen -r 5536
+$ screen -r 5589
+```
+
+Adding the rest of the name of the string is optional in this case.
+
+#### Named screens
+
+If you know you’ll have multiple screens, you might want to be able to connect to a screen using a name you choose. This is easier than choosing from a list of numbers that only reflect the process IDs of the screen sessions. To do that, use the _-S_ option as in the following example:
+
+```
+$ screen -S mywebapp
+```
+
+Then you can resume that screen in the future using this command:
+
+```
+$ screen -r mywebapp
+```
+
+#### Starting a process in the background using screen
+
+An optional argument is the command to be executed inside the created session. For example:
+
+```
+$ screen -S session_name command args
+```
+
+This would be the same as running:
+
+```
+$ screen -S session_name
+```
+
+…And then running this command inside the _screen_ session:
+
+```
+$ command args
+```
+
+The screen session will terminate when the command finishes its execution.
+
+This is made particularly useful by passing the **-dm** option, which starts the screen in the background without attaching to it. For example, you can copy a very large file in the background by running this command:
+
+```
+$ screen -S copy -d -m cp /path/to/file /path/to/output
+```
+
+### Other screen features
+
+Now that you’ve seen the basics, let’s see some of the other most commonly used screen features.
+
+#### Easily switching between windows in a screen
+
+When inside a screen, you can create a new window using **C-a c**. After you do that, you can switch between the windows using **C-a n** to go to the next one and **C-a p** to go to the previous window. You can destroy (kill) the current window with **C-a k**.
+
+#### Copying and pasting text
+
+The screen tool also enables you to copy any text on the screen and paste it later wherever you can type some text.
+
+The **C-a [** keybinding frees your cursor of any constraints and lets it go anywhere your will takes it using the arrow keys on your keyboard. To select and copy text, move to the start of the string you want to copy, and press **Enter** on the keyboard. Then move the cursor to the end of the text you want to copy and press **Enter** again.
+
+After you’ve done that, use **C-a ]** to paste that text in your shell. Or you can open a text editor like _vim_ or _nano_ and paste the text you copied there.
+
+### Important notes about screen
+
+Here are some other tips to keep in mind when using this utility.
+
+#### Privileged sessions vs. sudo inside a screen
+
+What if you need to run a command with root privileges inside screen? You can run either of these commands:
+
+```
+$ screen -S sessionname sudo command
+$ sudo screen -S sessionname command
+```
+
+Notice that the second command is like running this command:
+
+```
+# screen -S sessionname command
+```
+
+Seeing things this way makes it a lot more obvious coupled with the fact that each screen is associated to a user:
+
+ * The first one creates a screen with root privileges that can be accessed by the current user even if, within that screen, they switch to another user or _root_ using the _sudo -i_ command.
+ * The second one creates a screen that can only be accessed by the _root_ user, or by running _sudo screen -r_ as a user with the [appropriate _sudo_ access][3].
+
+
+
+#### Notes about screen in systemd units
+
+You might be tempted to run a screen session in the background as part of a systemd unit executed at startup, just like any Unix daemon. That way you can resume the screen session and interact with whatever you ran that way. That can work, but you need to consider that it requires the right setup.
+
+By default, [systemd assumes][4] services are either _oneshot,_ meaning they set up something and then shut down, or _simple_. A service is simple by default when you create a unit file with no _Type_. What you actually need to do is to set the _Type_ to _forking_, which describes _screen_‘s actual behavior when the **-dm** option is passed. It starts the process and then forks itself, leaving the process running in the background while the foreground process closes.
+
+If you don’t set that, that _screen_ behavior is interpreted by systemd as the service exiting or failing. This causes systemd to kill the background process when the foreground process exits, which is not what you want.
+
+* * *
+
+_Photo by [Vlad Tchompalov][5] on [Unsplash][6]._
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/make-sysadmin-work-on-fedora-easier-with-screen/
+
+作者：[Carmine Zaccagnino][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/carzacc/
+[b]: https://github.com/lujun9972
+[1]: https://fedoramagazine.org/wp-content/uploads/2019/12/screen-816x345.jpg
+[2]: https://fedoramagazine.org/what-is-an-init-system/
+[3]: https://fedoramagazine.org/howto-use-sudo/
+[4]: https://www.freedesktop.org/software/systemd/man/systemd.service.html
+[5]: https://unsplash.com/@tchompalov?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
+[6]: https://unsplash.com/s/photos/screen?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
diff --git a/sources/tech/20191219 An Actionable Guide to Enhance Your Online Privacy With Tor.md b/sources/tech/20191219 An Actionable Guide to Enhance Your Online Privacy With Tor.md
new file mode 100644
index 0000000000..36fb202b9e
--- /dev/null
+++ b/sources/tech/20191219 An Actionable Guide to Enhance Your Online Privacy With Tor.md
@@ -0,0 +1,260 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (An Actionable Guide to Enhance Your Online Privacy With Tor)
+[#]: via: (https://itsfoss.com/tor-guide/)
+[#]: author: (Community https://itsfoss.com/author/itsfoss/)
+
+An Actionable Guide to Enhance Your Online Privacy With Tor
+======
+
+In a world where technology is rapidly evolving, companies are gathering data and information from users in order to optimize the functionality of their applications as much as possible, privacy has slowly begun to fade and look like a myth.
+
+Many people believe that completely concealing their identity online is a difficult process that cannot be achieved. But of course, for security experts and for those who are optimistic that anonymity will not be lost, the answer is that we can enhance anonymity on the Internet.
+
+This can clearly be achieved with the help of _Tor_. Tor stands for The Onion Routing.
+
+Tor is a free and open source software developed by the [Tor project][1], a non-profit organization focusing on the freedom and privacy of users on the Internet.
+
+![Tor Onion][2]
+
+Let’s see below how you can enhance our online privacy with Tor.
+
+### What is Tor?
+
+As I mentioned before, Tor is a free open source software which defends users’ privacy. Specifically, The Onion Router software is being used by students, companies, universities, reporters who maybe want to share an idea anonymously for many years. In order to conceal users’ identities, Tor routes traffic through a worldwide overlay network which consisting of thousand of relays.
+
+![Tor Network][3]
+
+In addition, it has a very handy functionality as it encrypts the data multiple times, including the next IP address for the node it is intended for, and sends it through a virtual circuit that includes a random node. Each node decrypts a layer of encrypted information in order to reveal the next node. The result is that the remaining encrypted information will be decrypted at the last node without revealing the source IP address. This process builds the Tor circuit.
+
+### How to install Tor on Linux
+
+Since Tor is one of the most popular software in the open source community, it can be found in almost every Linux distribution’s repository.
+
+For Ubuntu-based distributions, it is available in the universe repository. We have a separate article on [installing Tor browser on Ubuntu][4] which you may refer. It also has a few tips on using the browser that you may find useful.
+
+I am using Debian 10 so I’ll mention the steps for installing Tor on Debian:
+
+All you have to do is to add the backport repository to our sources.list and then we can easily install Tor and its components. Use the following commands:
+
+```
+echo "deb http://deb.debian.org/debian buster-backports main contrib" > /etc/apt/sources.list.d/buster-backports.list
+
+sudo apt update
+sudo apt install tor torbrowser-launcher
+```
+
+Remember!
+
+Do not run Tor as root, as it is not secure for your operating system. It is recommended to run it as a normal user.
+
+### What can you achieve with Tor?
+
+As we move on, you will see numerous privacy enhancements that can be impressively accomplished with Tor.
+
+Particularly, below we will see the topics that will be covered:
+
+ * Explore the Tor Network with Tor Browser
+ * Use Tor through Firefox
+
+
+
+Note: It would be helpful to take into consideration that Tor can be used alongside with many applications, so anyone can privately use the application she/he desires.
+
+ * Create a hidden Tor service
+ * Create a middle Tor relay
+
+
+
+#### Explore the Tor network with Tor browser
+
+To connect to the Tor network through the Tor browser, open the application that will be with the rest of your internet applications or type in the terminal:
+
+```
+torbrowser-launcher
+```
+
+Initially, a window will appear, which allows some settings to be modified in the connection. For example, for users who wish to access the Tor network, and their country does not allow them, they must have the necessary settings for a successful connection.
+
+![Tor Network Settings][5]
+
+You can always request a bridge from the Tor Database, [BridgeDB][6].
+
+If everything is under control, all that’s left is to connect.
+
+![Tor Browser][7]
+
+_**Welcome to Tor..**_
+
+It is worth mentioning that it would be helpful and safe to avoid adding extensions to Tor Browser as it can reveal user’s real location and IP address to the website operators.
+
+It is also recommended to avoid downloading torrents, to avoid IP revealing.
+
+_**Let the exploration begin ..**_
+
+#### How to use Tor through Firefox
+
+You don’t always need to use the Tor browser. The [awesome Firefox][8] allows you to use Tor network.
+
+In order to connect to tor network via Firefox, you must first open the tor service. To do this, execute the following command:
+
+```
+sudo service tor start
+```
+
+To ensure that the tor is active, you can observe the open links. Below you can see the running port, which is the 9050.
+
+```
+netstat -nvlp
+```
+
+Here’s the output:
+
+```
+.. .. .. .. ..
+
+tcp 0 0 127.0.0.1:9050 0.0.0.0:* LISTEN
+```
+
+The only thing left to do is to set Firefox to be connected through Tor proxy.
+
+Go to Preferences → General → Network Proxy and set the localhost IP and Tor listening port to SOCKS v5 as shows below:
+
+![Setting Tor in Firefox][9]
+
+#### How to create a Tor Hidden Service
+
+Ttry to search for the term “Hidden Wiki”, you will notice that you will not find any hidden content. This is because the content discussed above does not represent the standard domain, but a top-level domain that can be found through Tor. This domain is .onion.
+
+So let’s see how you can create your own _**secret onion service**_.
+
+With the installation of Tor, torrc was created. The torrc is the tor configuration file, and its path is /etc/tor/torrc.
+
+Note: In order for modification to be applied, the ‘#’ symbol must be removed from the start of the line.
+
+To create the onion service you need to modify the configuration file so that after its modification it contains our service.
+
+You can open the file with a [command line text editor][10] of your choice. Personally, my favourite text editor is Vim. If Vim is used and you have any difficulty, you can take a look at the following article to make the situation clearer.
+
+In torrc you will find a lot of content, which can, in any case, be analyzed in a related article. For the time being, we are interested in the line mentioned by “Hidden Service”.
+
+![][11]
+
+At first glance, it can be understood that a path, a network address and finally two doors should be set.
+
+```
+HiddenServiceDir /var/lib/tor/hidden_service/
+```
+
+‘HiddenServiceDir’ denotes the path the hostname will generate, which will then be the user visit point to the secret service created.
+
+HiddenServicePort 80 127.0.0.1:80
+
+‘HiddenServicePort’ indicates which address and port the .onion service will be connected to.
+
+For example, below is the creation of a hidden service named linuxhandbook, which as a port destination will have port 80, as the address will have localhost’s IP and port 80 respectively.
+
+![][12]
+
+Finally, the only thing left to complete the creation is to restart the tor service. Once the tor is restarted, the /var/lib/tor// path will have both the public and private secret service key, as well as the hostname file. The ‘Hostname’ file contains the .onion link provided for our onion site.
+
+Here is the output of my ‘hostname’ file.
+
+```
+ogl3kz3nfckz22xp4migfed76fgbofwueytf7z6d2tnlh7vuto3zjjad.onion
+```
+
+Just visit this link through your Tor Browser and you will see your up and running server based on a .onion domain.
+
+![Sample Onion Web Page][13]
+
+#### How to Create a Middle Tor Relay
+
+The Tor network, as mentioned before, is an open network, which consists of many nodes. Tor nodes are a creation of volunteers, that is, contributors to enhancing privacy. It is worth noting that the nodes are over 7000 and they are getting bigger day by day. Everyone’s contribution is always acceptable as we expand one of the predominantly largest networks worldwide.
+
+Tor contains Guard, Middle and Exit Relays. A Guard Relay is the the first relay of a Tor circuit. The Middle Relay is the second hop of the circuit. Guard and Middle Relays are listed in the public list of Tor relays. Exit Relay is the final relay of a tor circuit. It is a crucial relay, as it sends traffic out its destination.
+
+All relays are meaningful but in this article, we will cover about Middle relays.
+
+Here’s and image showing middle-relay traffic the last two months.
+
+![][14]
+
+Lets see how we can create a middle relay.
+
+Once again, in order to create your own middle relay, you have to modify the torrc file.
+
+In any case, as I mentioned above, you can uncomment the lines when you need your configuration to be enabled.
+
+However, it is feasible to copy the following lines and then modify them.
+
+```
+#change the nickname “Linuxhandbook” to a name that you like
+Nickname Linuxhandbook
+ORPort 443
+ExitRelay 0
+SocksPort 0
+ControlSocket 0
+#change the email address below and be aware that it will be published
+ContactInfo [email protected]
+```
+
+An explanation should make the situation clearer.
+
+ * Nickname: Set your own relay name.
+ * ORPort: Set a port which will be the relay’s listening port.
+ * ExitRelay: By default, is set to 0, we want to create a middle relay.
+
+
+
+Note: tor service needs to be open.
+
+You should see your middle-relay up and running in Tor Metrics after a few couple of hours. Therefore, it usually takes 3 hours to be published, according to [Tormetrics][15].
+
+Warning!
+
+For sure, some of you may have heard of the term “Deep Web”, “Hidden Wiki” and many other services that you haven’t been able to visit yet. Besides, you may have heard that there is content posted on the Tor network which may be illegal.
+
+In the Tor network, one can find almost anything, such as forums with any kind of discussion. Quite right, since there is no censorship in a network whose entities are anonymous. This is both good and bad at the same time.
+
+I am not going to give sermons here about what you should use and what you should not use. I believe that you are sensible enough to make that decision.
+
+In conclusion, you can thoroughly see, that one can, in any case, enhance their privacy as well as defend themselves from Internet censorship. I would love to hear your opinion about Tor.
+
+##### Panos
+
+Penetration Tester and Operating System developer
+
+Panos’ love for Free Open Source Software is invaluable. In his spare time, he observes the night sky with his telescope.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/tor-guide/
+
+作者：[Community][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/itsfoss/
+[b]: https://github.com/lujun9972
+[1]: https://www.torproject.org/
+[2]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/tor_onion.jpg?ssl=1
+[3]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/tor-network-diagram.png?ssl=1
+[4]: https://itsfoss.com/install-tar-browser-linux/
+[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/tor_browser.png?ssl=1
+[6]: https://www.bridgedb.org/
+[7]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/tor_firefox.jpg?ssl=1
+[8]: https://itsfoss.com/why-firefox/
+[9]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/tor_settings.png?ssl=1
+[10]: https://itsfoss.com/command-line-text-editors-linux/
+[11]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/create_tor_relay.jpg?ssl=1
+[12]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/create_tor_relay_2.jpg?ssl=1
+[13]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/onion_web_page.jpg?ssl=1
+[14]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/tor_relay.jpg?ssl=1
+[15]: https://metrics.torproject.org/
diff --git a/sources/tech/20191219 Creating a Bash script template.md b/sources/tech/20191219 Creating a Bash script template.md
new file mode 100644
index 0000000000..3cfd549c3d
--- /dev/null
+++ b/sources/tech/20191219 Creating a Bash script template.md
@@ -0,0 +1,236 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Creating a Bash script template)
+[#]: via: (https://opensource.com/article/19/12/bash-script-template)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+Creating a Bash script template
+======
+In the second article in this series, create a fairly simple template
+that you can use as a starting point for other Bash programs, then test
+it.
+![A person programming][1]
+
+In the [first article][2] in this series, you created a very small, one-line Bash script and explored the reasons for creating shell scripts and why they are the most efficient option for the system administrator, rather than compiled programs.
+
+In this second article, you will begin creating a Bash script template that can be used as a starting point for other Bash scripts. The template will ultimately contain a Help facility, a licensing statement, a number of simple functions, and some logic to deal with those options and others that might be needed for the scripts that will be based on this template.
+
+### Why create a template?
+
+Like automation in general, the idea behind creating a template is to be the "[lazy sysadmin][3]." A template contains the basic components that you want in all of your scripts. It saves time compared to adding those components to every new script and makes it easy to start a new script.
+
+Although it can be tempting to just throw a few command-line Bash statements together into a file and make it executable, that can be counterproductive in the long run. A well-written and well-commented Bash program with a Help facility and the capability to accept command-line options provides a good starting point for sysadmins who maintain the program, which includes the programs that _you_ write and maintain.
+
+### The requirements
+
+You should always create a set of requirements for every project you do. This includes scripts, even if it is a simple list with only two or three items on it. I have been involved in many projects that either failed completely or failed to meet the customer's needs, usually due to the lack of a requirements statement or a poorly written one.
+
+The requirements for this Bash template are pretty simple:
+
+ 1. Create a template that can be used as the starting point for future Bash programming projects.
+ 2. The template should follow standard Bash programming practices.
+ 3. It must include:
+ * A heading section that can be used to describe the function of the program and a changelog
+ * A licensing statement
+ * A section for functions
+ * A Help function
+ * A function to test whether the program user is root
+ * A method for evaluating command-line options
+
+
+
+### The basic structure
+
+A basic Bash script has three sections. Bash has no way to delineate sections, but the boundaries between the sections are implicit.
+
+ * All scripts must begin with the shebang (**#!**), and this must be the first line in any Bash program.
+ * The functions section must begin after the shebang and before the body of the program. As part of my need to document everything, I place a comment before each function with a short description of what it is intended to do. I also include comments inside the functions to elaborate further. Short, simple programs may not need functions.
+ * The main part of the program comes after the function section. This can be a single Bash statement or thousands of lines of code. One of my programs has a little over 200 lines of code, not counting comments. That same program has more than 600 comment lines.
+
+
+
+That is all there is—just three sections in the structure of any Bash program.
+
+### Leading comments
+
+I always add more than this for various reasons. First, I add a couple of sections of comments immediately after the shebang. These comment sections are optional, but I find them very helpful.
+
+The first comment section is the program name and description and a change history. I learned this format while working at IBM, and it provides a method of documenting the long-term development of the program and any fixes applied to it. This is an important start in documenting your program.
+
+The second comment section is a copyright and license statement. I use GPLv2, and this seems to be a standard statement for programs licensed under GPLv2. If you use a different open source license, that is fine, but I suggest adding an explicit statement to the code to eliminate any possible confusion about licensing. Scott Peterson's article [_The source code is the license_][4] helps explain the reasoning behind this.
+
+So now the script looks like this:
+
+
+```
+#!/bin/bash
+################################################################################
+# scriptTemplate #
+# #
+# Use this template as the beginning of a new program. Place a short #
+# description of the script here. #
+# #
+# Change History #
+# 11/11/2019 David Both Original code. This is a template for creating #
+# new Bash shell scripts. #
+# Add new history entries as needed. #
+# #
+# #
+################################################################################
+################################################################################
+################################################################################
+# #
+# Copyright (C) 2007, 2019 David Both #
+# [LinuxGeek46@both.org][5] #
+# #
+# This program is free software; you can redistribute it and/or modify #
+# it under the terms of the GNU General Public License as published by #
+# the Free Software Foundation; either version 2 of the License, or #
+# (at your option) any later version. #
+# #
+# This program is distributed in the hope that it will be useful, #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
+# GNU General Public License for more details. #
+# #
+# You should have received a copy of the GNU General Public License #
+# along with this program; if not, write to the Free Software #
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #
+# #
+################################################################################
+################################################################################
+################################################################################
+
+echo "hello world!"
+```
+
+Run the revised program to verify that it still works as expected.
+
+### About testing
+
+Now is a good time to talk about testing.
+
+> "_There is always one more bug."_
+> — Lubarsky's Law of Cybernetic Entomology
+
+Lubarsky—whoever that might be—is correct. You can never find all the bugs in your code. For every bug I find, there always seems to be another that crops up, usually at a very inopportune time.
+
+Testing is not just about programs. It is also about verification that problems—whether caused by hardware, software, or the seemingly endless ways users can find to break things—that are supposed to be resolved actually are. Just as important, testing is also about ensuring that the code is easy to use and the interface makes sense to the user.
+
+Following a well-defined process when writing and testing shell scripts can contribute to consistent and high-quality results. My process is simple:
+
+ 1. Create a simple test plan.
+ 2. Start testing right at the beginning of development.
+ 3. Perform a final test when the code is complete.
+ 4. Move to production and test more.
+
+
+
+#### The test plan
+
+There are lots of different formats for test plans. I have worked with the full range—from having it all in my head; to a few notes jotted down on a sheet of paper; and all the way to a complex set of forms that require a full description of each test, which functional code it would test, what the test would accomplish, and what the inputs and results should be.
+
+Speaking as a sysadmin who has been (but is not now) a tester, I try to take the middle ground. Having at least a short written test plan will ensure consistency from one test run to the next. How much detail you need depends upon how formal your development and test functions are.
+
+The sample test plan documents I found using Google were complex and intended for large organizations with very formal development and test processes. Although those test plans would be good for people with "test" in their job title, they do not apply well to sysadmins' more chaotic and time-dependent working conditions. As in most other aspects of the job, sysadmins need to be creative. So here is a short list of things to consider including in your test plan. Modify it to suit your needs:
+
+ * The name and a short description of the software being tested
+ * A description of the software features to be tested
+ * The starting conditions for each test
+ * The functions to follow for each test
+ * A description of the desired outcome for each test
+ * Specific tests designed to test for negative outcomes
+ * Tests for how the program handles unexpected inputs
+ * A clear description of what constitutes pass or fail for each test
+ * Fuzzy testing, which is described below
+
+
+
+This list should give you some ideas for creating your test plans. Most sysadmins should keep it simple and fairly informal.
+
+#### Test early—test often
+
+I always start testing my shell scripts as soon as I complete the first portion that is executable. This is true whether I am writing a short command-line program or a script that is an executable file.
+
+I usually start creating new programs with the shell script template. I write the code for the Help function and test it. This is usually a trivial part of the process, but it helps me get started and ensures that things in the template are working properly at the outset. At this point, it is easy to fix problems with the template portions of the script or to modify it to meet needs that the standard template does not.
+
+Once the template and Help function are working, I move on to creating the body of the program by adding comments to document the programming steps required to meet the program specifications. Now I start adding code to meet the requirements stated in each comment. This code will probably require adding variables that are initialized in that section of the template—which is now becoming a shell script.
+
+This is where testing is more than just entering data and verifying the results. It takes a bit of extra work. Sometimes I add a command that simply prints the intermediate result of the code I just wrote and verify that. For more complex scripts, I add a **-t** option for "test mode." In this case, the internal test code executes only when the **-t** option is entered on the command line.
+
+#### Final testing
+
+After the code is complete, I go back to do a complete test of all the features and functions using known inputs to produce specific outputs. I also test some random inputs to see if the program can handle unexpected input.
+
+Final testing is intended to verify that the program is functioning essentially as intended. A large part of the final test is to ensure that functions that worked earlier in the development cycle have not been broken by code that was added or changed later in the cycle.
+
+If you have been testing the script as you add new code to it, you may think there should not be any surprises during the final test. Wrong! There are always surprises during final testing. Always. Expect those surprises, and be ready to spend time fixing them. If there were never any bugs discovered during final testing, there would be no point in doing a final test, would there?
+
+#### Testing in production
+
+Huh—what?
+
+> "Not until a program has been in production for at least six months will the most harmful error be discovered."
+> — Troutman's Programming Postulates
+
+Yes, testing in production is now considered normal and desirable. Having been a tester myself, this seems reasonable. "But wait! That's dangerous," you say. My experience is that it is no more dangerous than extensive and rigorous testing in a dedicated test environment. In some cases, there is no choice because there is no test environment—only production.
+
+Sysadmins are no strangers to the need to test new or revised scripts in production. Anytime a script is moved into production, that becomes the ultimate test. The production environment constitutes the most critical part of that test. Nothing that testers can dream up in a test environment can fully replicate the true production environment.
+
+The allegedly new practice of testing in production is just the recognition of what sysadmins have known all along. The best test is production—so long as it is not the only test.
+
+#### Fuzzy testing
+
+This is another of those buzzwords that initially caused me to roll my eyes. Its essential meaning is simple: have someone bang on the keys until something happens, and see how well the program handles it. But there really is more to it than that.
+
+Fuzzy testing is a bit like the time my son broke the code for a game in less than a minute with random input. That pretty much ended my attempts to write games for him.
+
+Most test plans utilize very specific input that generates a specific result or output. Regardless of whether the test defines a positive or negative outcome as a success, it is still controlled, and the inputs and results are specified and expected, such as a specific error message for a specific failure mode.
+
+Fuzzy testing is about dealing with randomness in all aspects of the test, such as starting conditions, very random and unexpected input, random combinations of options selected, low memory, high levels of CPU contending with other programs, multiple instances of the program under test, and any other random conditions that you can think of to apply to the tests.
+
+I try to do some fuzzy testing from the beginning. If the Bash script cannot deal with significant randomness in its very early stages, then it is unlikely to get better as you add more code. This is a good time to catch these problems and fix them while the code is relatively simple. A bit of fuzzy testing at each stage is also useful in locating problems before they get masked by even more code.
+
+After the code is completed, I like to do some more extensive fuzzy testing. Always do some fuzzy testing. I have certainly been surprised by some of the results. It is easy to test for the expected things, but users do not usually do the expected things with a script.
+
+### Previews of coming attractions
+
+This article accomplished a little in the way of creating a template, but it mostly talked about testing. This is because testing is a critical part of creating any kind of program. In the next article in this series, you will add a basic Help function along with some code to detect and act on options, such as **-h**, to your Bash script template.
+
+### Resources
+
+ * [How to program with Bash: Syntax and tools][6]
+ * [How to program with Bash: Logical operators and shell expansions][7]
+ * [How to program with Bash: Loops][8]
+
+
+
+* * *
+
+_This series of articles is partially based on Volume 2, Chapter 10 of David Both's three-part Linux self-study course, [Using and Administering Linux—Zero to SysAdmin][9]._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/bash-script-template
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb (A person programming)
+[2]: https://opensource.com/article/19/12/introduction-automation-bash-scripts
+[3]: https://opensource.com/article/18/7/how-be-lazy-sysadmin
+[4]: https://opensource.com/article/17/12/source-code-license
+[5]: mailto:LinuxGeek46@both.org
+[6]: https://opensource.com/article/19/10/programming-bash-syntax-tools
+[7]: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
+[8]: https://opensource.com/article/19/10/programming-bash-loops
+[9]: http://www.both.org/?page_id=1183
diff --git a/sources/tech/20191219 Go mouseless with the Linux Ratpoison window manager.md b/sources/tech/20191219 Go mouseless with the Linux Ratpoison window manager.md
new file mode 100644
index 0000000000..fa66d18314
--- /dev/null
+++ b/sources/tech/20191219 Go mouseless with the Linux Ratpoison window manager.md
@@ -0,0 +1,107 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Go mouseless with the Linux Ratpoison window manager)
+[#]: via: (https://opensource.com/article/19/12/ratpoison-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Go mouseless with the Linux Ratpoison window manager
+======
+This article is part of a special series of 24 days of Linux desktops.
+If you'd rather live in a terminal all day and avoid mousing around, the
+Ratpoison window manager is the solution for you.
+![Buildings with different color windows][1]
+
+Maybe you don't like desktops. Maybe even a lightweight window manager seems excessive to you. Maybe all you really use is a graphical user interface (GUI) application or two, and you're otherwise perfectly happy living in a terminal all day. If one or more of these sentiments sound familiar, then [Ratpoison][2] is the solution.
+
+![Ratpoison][3]
+
+The Ratpoison window manager models itself after [GNU Screen][4]. All window controls are performed with keyboard shortcuts, so you don't have to grab the mouse just to move a window out of your way. The trade-off is that it's impossibly minimalistic, which is, conveniently, also its greatest strength.
+
+### Installing Ratpoison
+
+Install Ratpoison from your distribution's software repository. After installing it, log out of your current desktop session so you can log into your new one. By default, your session manager (KDM, GDM, LightDM, or XDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+With GDM:
+
+![][5]
+
+With SDDM:
+
+![][6]
+
+### Ratpoison desktop tour
+
+The first time you log into Ratpoison, you are greeted by a black screen with some text in the upper-right corner telling you that you can press **Ctrl+t** for help.
+
+That's all there is to the Ratpoison desktop.
+
+### Interacting with Ratpoison
+
+Ratpoison documentation uses Emacs-style notation for keyboard controls, so I'll use the same notation in this article. If you're unfamiliar with Emacs or GNU Screen, it can look confusing at first, so here's explicit instruction on how to "decode" this style of notation. The Control key on your keyboard is written as **C-**. To trigger Ratpoison's command mode, you press **C-t**, which means that you press **Ctrl+t**.
+
+Since the **C-t** shortcut puts you into command mode, it's expected that some other key sequence will follow. For instance, to launch an xterm window, press **Ctrl+t**, just as you would when opening a new tab in a web browser, then press **c**. This may feel a little unnatural at first, because most of the keyboard shortcuts you're used to probably involve only one action. Ratpoison (and GNU Screen and Emacs) more often involve two.
+
+The first application you probably should launch is either Emacs or a terminal.
+
+In Ratpoison, your terminal is your exclusive gateway to the rest of the computer because there's no application menu or icons to click. The default terminal is the humble xterm, and it's available with the **C-t c** shortcut (I remember the **c** as being short for "console").
+
+#### Launching applications
+
+I usually start with Emacs instead, because it has most of the features I use anyway, including the **shell** terminal and the **dired** file manager. To start an arbitrary application in Ratpoison, press **C-t** and then the **!** (exclamation point) symbol. This provides a prompt in the upper-right corner of the screen. Type the command for the application you want to start and press **Return** or **Enter** to launch it.
+
+#### Switching windows
+
+Each application you launch takes over the entire screen by default. That means if [urxvt][7] is running, and then you launch Emacs, you can no longer interact with urxvt. Because switching back and forth between two application windows is a pretty common task, Ratpoison assigns it to the same keystroke as your usual Ratpoison command: **C-t C-t**. That means you press **Ctrl+t** once, and then **Ctrl+t** a second time. This is a toggle, like the default (at least in KDE and GNOME) behavior of a quick **Alt+Tab**.
+
+To cycle through all open windows, use **C-t n** for _next_ and **C-t p** for _previous_.
+
+#### Tiling window manager
+
+You're free to use Ratpoison as a full-screen viewscreen, but most of us are used to seeing more than one window at a time. To allow that, Ratpoison lets you split your screen into frames or tiles and launch an application within each space.
+
+![Ratpoison in split-screen mode][8]
+
+With at least one application open, you can split the screen horizontally with **C-t s** (that's a lowercase "s") or vertically with **C-t S** (that's a capital "S").
+
+To switch to another frame, use **C-t Tab**.
+
+To remove another frame, press **C-t R**.
+
+#### Moving windows in split-screen mode
+
+Rearranging frames when Ratpoison has been split into several parts is done with the **Ctrl** key and a corresponding **Arrow** key. For instance, suppose you have a vertical split in the top half of your screen and a single frame in the bottom half. If an application is in the top-left frame, and you want to move it to the lower half of the screen, then—with that application active (use **C-t Tab** to get there)—press **C-t** to enter command mode and then **C-Down** (that's **Ctrl** with the **Down arrow** key). The application moves to the bottom half of the screen, with the application that took up the bottom half moving into the top-left.
+
+To move that application to the top-right frame instead, press **C-t Right** (**Ctrl** with the **Right arrow** key).
+
+To remove the top-left frame entirely, use **C-t R**. This doesn't kill the application in the frame, it only removes the frame from your viewport. The application that once occupied the frame is sent to the background and can be reached by cycling through the windows as usual (**C-t n**, for instance).
+
+### Why you need to try Ratpoison
+
+Ratpoison is a great example of an early (but current) tiling window manager. Other window managers like it exist, and some desktops even borrow concepts from this tradition by offering tiling features (KWin in KDE, for example, has an option to spawn new windows in tiles across the desktop).
+
+If you've never used a tiling window manager, you owe it to yourself to try at least once. First, make it a goal to use Ratpoison. Then make it a goal to get through a whole afternoon without your mouse. Once you get the hang of it, you might be surprised at how quickly you can work.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/ratpoison-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/colors-colorful-box-rectangle.png?itok=doWmqCdf (Buildings with different color windows)
+[2]: https://www.nongnu.org/ratpoison/
+[3]: https://opensource.com/sites/default/files/uploads/advent-ratpoison.png (Ratpoison)
+[4]: https://opensource.com/article/17/3/introduction-gnu-screen
+[5]: https://opensource.com/sites/default/files/advent-gdm_1.jpg
+[6]: https://opensource.com/sites/default/files/advent-kdm_0.jpg
+[7]: https://opensource.com/article/19/10/why-use-rxvt-terminal
+[8]: https://opensource.com/sites/default/files/uploads/advent-ratpoison-split.jpg (Ratpoison in split-screen mode)
diff --git a/sources/tech/20191220 4 ways to volunteer this holiday season.md b/sources/tech/20191220 4 ways to volunteer this holiday season.md
new file mode 100644
index 0000000000..e90a48cebc
--- /dev/null
+++ b/sources/tech/20191220 4 ways to volunteer this holiday season.md
@@ -0,0 +1,67 @@
+[#]: collector: (lujun9972)
+[#]: translator: (Morisun029)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (4 ways to volunteer this holiday season)
+[#]: via: (https://opensource.com/article/19/12/ways-volunteer)
+[#]: author: (John Jones https://opensource.com/users/johnjones4)
+
+4 ways to volunteer this holiday season
+======
+Looking to spread some holiday cheer? Donate your talents to open source
+organizations that help communities in need.
+![Gift box opens with colors coming out][1]
+
+Social impact happens when leaders deploy individuals and resources to make positive change, but many social efforts are lacking technology resources that are up to the task of serving these change-makers. However, there are organizations helping to accelerate tech for good by connecting developers who want to make a change with communities and nonprofits who desperately need better technology. These organizations often serve specific audiences and recruit specific kinds of technologists, but they all share a common thread: open source.
+
+As developers, we all seek to participate in the open source community for a variety of reasons. Some participate for professional development, some participate so that they may collaborate with a vast, impressive network of technologists, and others participate because they know their contributions are necessary for the success of a project. Why not also volunteer your talents as a developer to an effort that needs them, and contribute to open source all at the same time? The organizations below are prime examples of how you can do that.
+
+### Code for America
+
+Code for America is an example of how government can still be by the people and for the people in the digital age. Through its Brigade Network, the organization has cultivated a national alliance of volunteer programmers, data scientists, concerned citizens, and designers organized in cities all over the United States. These local affiliates host regular meet-ups which are open to the community to both pitch new projects to the group and collaborate on ongoing efforts. To match volunteers with projects, the brigades’ websites often list the specific skills needed for a project such as data analysis, content creation, and JavaScript. While the brigades focus on local issues, shared experiences like natural disasters can foster collaboration. For example, a multi-brigade effort from the New Orleans, Houston, and Tampa Bay teams developed a hurricane response website that can be quickly adapted to different cities when disaster strikes.
+
+To get involved, visit Code for America’s [website][2] for a list of its over 70 brigades, and a path for individuals to start their own if there is not one already in their community.
+
+### Code for Change
+
+Code for Change shows that social impact can start even in high school. A group of high school coders in Indianapolis started their own club to give back to local organizations by creating open source software solutions to issues in their community. Code for Change encourages local organizations to reach out with a project idea, and the student group steps in to develop a completely free and open source solution. The group has developed projects such as "Sapphire," which optimized volunteer management systems for a local refugee organization, and a Civil Rights Commission complaint form that makes it easier for citizens to voice their concerns online.
+
+For more information on how to create a Code for Change chapter in your own community, [visit their website][3].
+
+### Python for Good/Ruby for Good
+
+Python for Good and Ruby for Good are twin annual events in Portland, Oregon and Fairfax, Virginia, that bring people together to develop and program solutions for those respective communities. Over a weekend, individuals get together to hear pitches from local nonprofits and tackle their issues by building open source solutions. In 2017, Ruby For Good participants created "Justice for Juniors," which mentors and tutors current and formerly incarcerated youths to integrate them back into the community. Participants have also created "Diaperbase," an inventory management system that has been used by diaper banks all over the United States. One of the main objectives of these events is to bring organizations and people from seemingly different industries and mindsets to come together for a common good. Companies can sponsor the events, nonprofits can submit project ideas, and people of all skill levels can register to attend the event and contribute. Through their bicoastal efforts, Ruby for Good and Python for Good are living up to their motto of "making the world gooder."
+
+[Ruby for Good][4] is held in the summer and hosted on George Mason’s campus in Fairfax, Virginia.
+
+### Social Coder
+
+UK-based Ed Guiness created Social Coder to bring together volunteers and charities to create and use open source projects for nonprofits across six continents. Social Coder actively recruits a network of skilled IT volunteers from all over the world and matches them to charities and nonprofits registered through Social Coder. Projects can range from simple website updates to entire mobile app development.
+
+For example, PHASE Worldwide, a small non-governmental association supporting efforts in Nepal, got access to key support and expertise leveraging open source technology because of Social Coder.
+
+While a bulk of the charities already partnered with Social Coder are based in the UK, organizations in other countries are welcome. Through their website, individuals can register to work on social software projects and connect with organizations and charities seeking their help.
+
+Individuals interested in volunteering with Social Coder can sign up [here][5].
+
+The four-day-long siege of a Nairobi mall ended Tuesday with a death toll of more than 60 people –...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/ways-volunteer
+
+作者：[John Jones][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/johnjones4
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_gift_giveaway_box_520x292.png?itok=w1YQhNH1 (Gift box opens with colors coming out)
+[2]: https://brigade.codeforamerica.org/
+[3]: http://codeforchange.herokuapp.com/
+[4]: https://rubyforgood.org/
+[5]: https://socialcoder.org/Home/Programmer
diff --git a/sources/tech/20191220 How to add a Help facility to your Bash program.md b/sources/tech/20191220 How to add a Help facility to your Bash program.md
new file mode 100644
index 0000000000..d51466411f
--- /dev/null
+++ b/sources/tech/20191220 How to add a Help facility to your Bash program.md
@@ -0,0 +1,346 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to add a Help facility to your Bash program)
+[#]: via: (https://opensource.com/article/19/12/help-bash-program)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+How to add a Help facility to your Bash program
+======
+In the third article in this series, learn about using functions as you
+create a simple Help facility for your Bash script.
+![bash logo on green background][1]
+
+In the [first article][2] in this series, you created a very small, one-line Bash script and explored the reasons for creating shell scripts and why they are the most efficient option for the system administrator, rather than compiled programs. In the [second article][3], you began the task of creating a fairly simple template that you can use as a starting point for other Bash programs, then explored ways to test it.
+
+This third of the four articles in this series explains how to create and use a simple Help function. While creating your Help facility, you will also learn about using functions and how to handle command-line options such as **-h**.
+
+### Why Help?
+
+Even fairly simple Bash programs should have some sort of Help facility, even if it is fairly rudimentary. Many of the Bash shell programs I write are used so infrequently that I forget the exact syntax of the command I need. Others are so complex that I need to review the options and arguments even when I use them frequently.
+
+Having a built-in Help function allows you to view those things without having to inspect the code itself. A good and complete Help facility is also a part of program documentation.
+
+### About functions
+
+Shell functions are lists of Bash program statements that are stored in the shell's environment and can be executed, like any other command, by typing their name at the command line. Shell functions may also be known as procedures or subroutines, depending upon which other programming language you are using.
+
+Functions are called in scripts or from the command-line interface (CLI) by using their names, just as you would for any other command. In a CLI program or a script, the commands in the function execute when they are called, then the program flow sequence returns to the calling entity, and the next series of program statements in that entity executes.
+
+The syntax of a function is:
+
+
+```
+`FunctionName(){program statements}`
+```
+
+Explore this by creating a simple function at the CLI. (The function is stored in the shell environment for the shell instance in which it is created.) You are going to create a function called **hw**, which stands for "hello world." Enter the following code at the CLI and press **Enter**. Then enter **hw** as you would any other shell command:
+
+
+```
+[student@testvm1 ~]$ hw(){ echo "Hi there kiddo"; }
+[student@testvm1 ~]$ hw
+Hi there kiddo
+[student@testvm1 ~]$
+```
+
+OK, so I am a little tired of the standard "Hello world" starter. Now, list all of the currently defined functions. There are a lot of them, so I am showing just the new **hw** function. When it is called from the command line or within a program, a function performs its programmed task and then exits and returns control to the calling entity, the command line, or the next Bash program statement in a script after the calling statement:
+
+
+```
+[student@testvm1 ~]$ declare -f | less
+<snip>
+hw ()
+{
+ echo "Hi there kiddo"
+}
+<snip>
+```
+
+Remove that function because you do not need it anymore. You can do that with the **unset** command:
+
+
+```
+[student@testvm1 ~]$ unset -f hw ; hw
+bash: hw: command not found
+[student@testvm1 ~]$
+```
+
+### Creating the Help function
+
+Open the **hello** program in an editor and add the Help function below to the **hello** program code after the copyright statement but before the **echo "Hello world!"** statement. This Help function will display a short description of the program, a syntax diagram, and short descriptions of the available options. Add a call to the Help function to test it and some comment lines that provide a visual demarcation between the functions and the main portion of the program:
+
+
+```
+################################################################################
+# Help #
+################################################################################
+Help()
+{
+ # Display Help
+ echo "Add description of the script functions here."
+ echo
+ echo "Syntax: scriptTemplate [-g|h|v|V]"
+ echo "options:"
+ echo "g Print the GPL license notification."
+ echo "h Print this Help."
+ echo "v Verbose mode."
+ echo "V Print software version and exit."
+ echo
+}
+
+################################################################################
+################################################################################
+# Main program #
+################################################################################
+################################################################################
+
+Help
+echo "Hello world!"
+```
+
+The options described in this Help function are typical for the programs I write, although none are in the code yet. Run the program to test it:
+
+
+```
+[student@testvm1 ~]$ ./hello
+Add description of the script functions here.
+
+Syntax: scriptTemplate [-g|h|v|V]
+options:
+g Print the GPL license notification.
+h Print this Help.
+v Verbose mode.
+V Print software version and exit.
+
+Hello world!
+[student@testvm1 ~]$
+```
+
+Because you have not added any logic to display Help only when you need it, the program will always display the Help. Since the function is working correctly, read on to add some logic to display the Help only when the **-h** option is used when you invoke the program at the command line.
+
+### Handling options
+
+A Bash script's ability to handle command-line options such as **-h** gives some powerful capabilities to direct the program and modify what it does. In the case of the **-h** option, you want the program to print the Help text to the terminal session and then quit without running the rest of the program. The ability to process options entered at the command line can be added to the Bash script using the **while** command (see [_How to program with Bash: Loops_][4] to learn more about **while**) in conjunction with the **getops** and **case** commands.
+
+The **getops** command reads any and all options specified at the command line and creates a list of those options. In the code below, the **while** command loops through the list of options by setting the variable **$options** for each. The **case** statement is used to evaluate each option in turn and execute the statements in the corresponding stanza. The **while** statement will continue to evaluate the list of options until they have all been processed or it encounters an exit statement, which terminates the program.
+
+Be sure to delete the Help function call just before the **echo "Hello world!"** statement so that the main body of the program now looks like this:
+
+
+```
+################################################################################
+################################################################################
+# Main program #
+################################################################################
+################################################################################
+################################################################################
+# Process the input options. Add options as needed. #
+################################################################################
+# Get the options
+while getopts ":h" option; do
+ case $option in
+ h) # display Help
+ Help
+ exit;;
+ esac
+done
+
+echo "Hello world!"
+```
+
+Notice the double semicolon at the end of the exit statement in the case option for **-h**. This is required for each option added to this case statement to delineate the end of each option.
+
+### Testing
+
+Testing is now a little more complex. You need to test your program with a number of different options—and no options—to see how it responds. First, test with no options to ensure that it prints "Hello world!" as it should:
+
+
+```
+[student@testvm1 ~]$ ./hello
+Hello world!
+```
+
+That works, so now test the logic that displays the Help text:
+
+
+```
+[student@testvm1 ~]$ ./hello -h
+Add description of the script functions here.
+
+Syntax: scriptTemplate [-g|h|t|v|V]
+options:
+g Print the GPL license notification.
+h Print this Help.
+v Verbose mode.
+V Print software version and exit.
+```
+
+That works as expected, so try some testing to see what happens when you enter some unexpected options:
+
+
+```
+[student@testvm1 ~]$ ./hello -x
+Hello world!
+[student@testvm1 ~]$ ./hello -q
+Hello world!
+[student@testvm1 ~]$ ./hello -lkjsahdf
+Add description of the script functions here.
+
+Syntax: scriptTemplate [-g|h|t|v|V]
+options:
+g Print the GPL license notification.
+h Print this Help.
+v Verbose mode.
+V Print software version and exit.
+
+[student@testvm1 ~]$
+```
+
+The program just ignores any options without specific responses without generating any errors. But notice the last entry (with **-lkjsahdf** for options): because there is an **h** in the list of options, the program recognizes it and prints the Help text. This testing has shown that the program doesn't have the ability to handle incorrect input and terminate the program if any is detected.
+
+You can add another case stanza to the case statement to match any option that doesn't have an explicit match. This general case will match anything you have not provided a specific match for. The case statement now looks like this, with the catch-all match of **\?** as the last case. Any additional specific cases must precede this final one:
+
+
+```
+while getopts ":h" option; do
+ case $option in
+ h) # display Help
+ Help
+ exit;;
+ \?) # incorrect option
+ echo "Error: Invalid option"
+ exit;;
+ esac
+done
+```
+
+Test the program again using the same options as before and see how it works now.
+
+### Where you are
+
+You have accomplished a good amount in this article by adding the capability to process command-line options and a Help procedure. Your Bash script now looks like this:
+
+
+```
+#!/usr/bin/bash
+################################################################################
+# scriptTemplate #
+# #
+# Use this template as the beginning of a new program. Place a short #
+# description of the script here. #
+# #
+# Change History #
+# 11/11/2019 David Both Original code. This is a template for creating #
+# new Bash shell scripts. #
+# Add new history entries as needed. #
+# #
+# #
+################################################################################
+################################################################################
+################################################################################
+# #
+# Copyright (C) 2007, 2019 David Both #
+# [LinuxGeek46@both.org][5] #
+# #
+# This program is free software; you can redistribute it and/or modify #
+# it under the terms of the GNU General Public License as published by #
+# the Free Software Foundation; either version 2 of the License, or #
+# (at your option) any later version. #
+# #
+# This program is distributed in the hope that it will be useful, #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
+# GNU General Public License for more details. #
+# #
+# You should have received a copy of the GNU General Public License #
+# along with this program; if not, write to the Free Software #
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #
+# #
+################################################################################
+################################################################################
+################################################################################
+
+################################################################################
+# Help #
+################################################################################
+Help()
+{
+ # Display Help
+ echo "Add description of the script functions here."
+ echo
+ echo "Syntax: scriptTemplate [-g|h|t|v|V]"
+ echo "options:"
+ echo "g Print the GPL license notification."
+ echo "h Print this Help."
+ echo "v Verbose mode."
+ echo "V Print software version and exit."
+ echo
+}
+
+################################################################################
+################################################################################
+# Main program #
+################################################################################
+################################################################################
+################################################################################
+# Process the input options. Add options as needed. #
+################################################################################
+# Get the options
+while getopts ":h" option; do
+ case $option in
+ h) # display Help
+ Help
+ exit;;
+ \?) # incorrect option
+ echo "Error: Invalid option"
+ exit;;
+ esac
+done
+
+echo "Hello world!"
+```
+
+Be sure to test this version of the program very thoroughly. Use random inputs and see what happens. You should also try testing valid and invalid options without using the dash (**-**) in front.
+
+### Next time
+
+In this article, you added a Help function as well as the ability to process command-line options to display it selectively. The program is getting a little more complex, so testing is becoming more important and requires more test paths in order to be complete.
+
+The next article will look at initializing variables and doing a bit of sanity checking to ensure that the program will run under the correct set of conditions.
+
+### Resources
+
+ * [How to program with Bash: Syntax and tools][6]
+ * [How to program with Bash: Logical operators and shell expansions][7]
+ * [How to program with Bash: Loops][4]
+
+
+
+* * *
+
+_This series of articles is partially based on Volume 2, Chapter 10 of David Both's three-part Linux self-study course, [Using and Administering Linux—Zero to SysAdmin][8]._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/help-bash-program
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/bash_command_line.png?itok=k4z94W2U (bash logo on green background)
+[2]: https://opensource.com/article/19/12/introduction-automation-bash-scripts
+[3]: https://opensource.com/article/19/12/creating-bash-script-template
+[4]: https://opensource.com/article/19/10/programming-bash-loops
+[5]: mailto:LinuxGeek46@both.org
+[6]: https://opensource.com/article/19/10/programming-bash-syntax-tools
+[7]: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
+[8]: http://www.both.org/?page_id=1183
diff --git a/sources/tech/20191221 Testing your Bash script.md b/sources/tech/20191221 Testing your Bash script.md
new file mode 100644
index 0000000000..4a8504cbe9
--- /dev/null
+++ b/sources/tech/20191221 Testing your Bash script.md
@@ -0,0 +1,288 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Testing your Bash script)
+[#]: via: (https://opensource.com/article/19/12/testing-bash-script)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+Testing your Bash script
+======
+In the fourth and final article in this series on automation with shell
+scripts, learn about initializing variables and ensuring your program
+runs correctly.
+![Team checklist and to dos][1]
+
+In the [first article][2] in this series, you created your first, very small, one-line Bash script and explored the reasons for creating shell scripts. In the [second article][3], you began creating a fairly simple template that can be a starting point for other Bash programs and began testing it. In the [third article][4], you created and used a simple Help function and learned about using functions and how to handle command-line options such as **-h**.
+
+This fourth and final article in the series gets into variables and initializing them as well as how to do a bit of sanity testing to help ensure the program runs under the proper conditions. Remember, the objective of this series is to build working code that will be used for a template for future Bash programming projects. The idea is to make getting started on new programming projects easy by having common elements already available in the template.
+
+### Variables
+
+The Bash shell, like all programming languages, can deal with variables. A variable is a symbolic name that refers to a specific location in memory that contains a value of some sort. The value of a variable is changeable, i.e., it is variable. If you are not familiar with using variables, read my article [_How to program with Bash: Syntax and tools_][5] before you go further.
+
+Done? Great! Let's now look at some good practices when using variables.
+
+I always set initial values for every variable used in my scripts. You can find this in your template script immediately after the procedures as the first part of the main program body, before it processes the options. Initializing each variable with an appropriate value can prevent errors that might occur with uninitialized variables in comparison or math operations. Placing this list of variables in one place allows you to see all of the variables that are supposed to be in the script and their initial values.
+
+Your little script has only a single variable, **$option**, so far. Set it by inserting the following lines as shown:
+
+
+```
+################################################################################
+################################################################################
+# Main program #
+################################################################################
+################################################################################
+# Initialize variables
+option=""
+################################################################################
+# Process the input options. Add options as needed. #
+################################################################################
+```
+
+Test this to ensure that everything works as it should and that nothing has broken as the result of this change.
+
+### Constants
+
+Constants are variables, too—at least they should be. Use variables wherever possible in command-line interface (CLI) programs instead of hard-coded values. Even if you think you will use a particular value (such as a directory name, a file name, or a text string) just once, create a variable and use it where you would have placed the hard-coded name.
+
+For example, the message printed as part of the main body of the program is a string literal, **echo "Hello world!"**. Change that to a variable. First, add the following statement to the variable initialization section:
+
+
+```
+`Msg="Hello world!"`
+```
+
+And now change the last line of the program from:
+
+
+```
+`echo "Hello world!"`
+```
+
+to:
+
+
+```
+`echo "$Msg"`
+```
+
+Test the results.
+
+### Sanity checks
+
+Sanity checks are simply tests for conditions that need to be true in order for the program to work correctly, such as: the program must be run as the root user, or it must run on a particular distribution and release of that distro. Add a check for _root_ as the running user in your simple program template.
+
+Testing that the root user is running the program is easy because a program runs as the user that launches it.
+
+The **id** command can be used to determine the numeric user ID (UID) the program is running under. It provides several bits of information when it is used without any options:
+
+
+```
+[student@testvm1 ~]$ id
+uid=1001(student) gid=1001(student) groups=1001(student),5000(dev)
+```
+
+Using the **-u** option returns just the user's UID, which is easily usable in your Bash program:
+
+
+```
+[student@testvm1 ~]$ id -u
+1001
+[student@testvm1 ~]$
+```
+
+Add the following function to the program. I added it after the Help procedure, but you can place it anywhere in the procedures section. The logic is that if the UID is not zero, which is always the root user's UID, the program exits:
+
+
+```
+################################################################################
+# Check for root. #
+################################################################################
+CheckRoot()
+{
+ if [ `id -u` != 0 ]
+ then
+ echo "ERROR: You must be root user to run this program"
+ exit
+ fi
+}
+```
+
+Now, add a call to the **CheckRoot** procedure just before the variable's initialization. Test this, first running the program as the student user:
+
+
+```
+[student@testvm1 ~]$ ./hello
+ERROR: You must be root user to run this program
+[student@testvm1 ~]$
+```
+
+then as the root user:
+
+
+```
+[root@testvm1 student]# ./hello
+Hello world!
+[root@testvm1 student]#
+```
+
+You may not always need this particular sanity test, so comment out the call to **CheckRoot** but leave all the code in place in the template. This way, all you need to do to use that code in a future program is to uncomment the call.
+
+### The code
+
+After making the changes outlined above, your code should look like this:
+
+
+```
+#!/usr/bin/bash
+################################################################################
+# scriptTemplate #
+# #
+# Use this template as the beginning of a new program. Place a short #
+# description of the script here. #
+# #
+# Change History #
+# 11/11/2019 David Both Original code. This is a template for creating #
+# new Bash shell scripts. #
+# Add new history entries as needed. #
+# #
+# #
+################################################################################
+################################################################################
+################################################################################
+# #
+# Copyright (C) 2007, 2019 David Both #
+# [LinuxGeek46@both.org][6] #
+# #
+# This program is free software; you can redistribute it and/or modify #
+# it under the terms of the GNU General Public License as published by #
+# the Free Software Foundation; either version 2 of the License, or #
+# (at your option) any later version. #
+# #
+# This program is distributed in the hope that it will be useful, #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
+# GNU General Public License for more details. #
+# #
+# You should have received a copy of the GNU General Public License #
+# along with this program; if not, write to the Free Software #
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #
+# #
+################################################################################
+################################################################################
+################################################################################
+
+################################################################################
+# Help #
+################################################################################
+Help()
+{
+ # Display Help
+ echo "Add description of the script functions here."
+ echo
+ echo "Syntax: scriptTemplate [-g|h|v|V]"
+ echo "options:"
+ echo "g Print the GPL license notification."
+ echo "h Print this Help."
+ echo "v Verbose mode."
+ echo "V Print software version and exit."
+ echo
+}
+
+################################################################################
+# Check for root. #
+################################################################################
+CheckRoot()
+{
+ # If we are not running as root we exit the program
+ if [ `id -u` != 0 ]
+ then
+ echo "ERROR: You must be root user to run this program"
+ exit
+ fi
+}
+
+################################################################################
+################################################################################
+# Main program #
+################################################################################
+################################################################################
+
+################################################################################
+# Sanity checks #
+################################################################################
+# Are we rnning as root?
+# CheckRoot
+
+# Initialize variables
+option=""
+Msg="Hello world!"
+################################################################################
+# Process the input options. Add options as needed. #
+################################################################################
+# Get the options
+while getopts ":h" option; do
+ case $option in
+ h) # display Help
+ Help
+ exit;;
+ \?) # incorrect option
+ echo "Error: Invalid option"
+ exit;;
+ esac
+done
+
+echo "$Msg"
+```
+
+### A final exercise
+
+You probably noticed that the Help function in your code refers to features that are not in the code. As a final exercise, figure out how to add those functions to the code template you created.
+
+### Summary
+
+In this article, you created a couple of functions to perform a sanity test for whether your program is running as root. Your program is getting a little more complex, so testing is becoming more important and requires more test paths to be complete.
+
+This series looked at a very minimal Bash program and how to build a script up a bit at a time. The result is a simple template that can be the starting point for other, more useful Bash scripts and that contains useful elements that make it easy to start new scripts.
+
+By now, you get the idea: Compiled programs are necessary and fill a very important need. But for sysadmins, there is always a better way. Always use shell scripts to meet your job's automation needs. Shell scripts are open; their content and purpose are knowable. They can be readily modified to meet different requirements. I have never found anything that I need to do in my sysadmin role that cannot be accomplished with a shell script.
+
+What you have created so far in this series is just the beginning. As you write more Bash programs, you will find more bits of code that you use frequently and should be included in your program template.
+
+### Resources
+
+ * [How to program with Bash: Syntax and tools][5]
+ * [How to program with Bash: Logical operators and shell expansions][7]
+ * [How to program with Bash: Loops][8]
+
+
+
+* * *
+
+_This series of articles is partially based on Volume 2, Chapter 10 of David Both's three-part Linux self-study course, [Using and Administering Linux—Zero to SysAdmin][9]._
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/testing-bash-script
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/todo_checklist_team_metrics_report.png?itok=oB5uQbzf (Team checklist and to dos)
+[2]: https://opensource.com/article/19/12/introduction-automation-bash-scripts
+[3]: https://opensource.com/article/19/12/creating-bash-script-template
+[4]: https://opensource.com/article/19/12/give-your-bash-program-some-help
+[5]: https://opensource.com/article/19/10/programming-bash-syntax-tools
+[6]: mailto:LinuxGeek46@both.org
+[7]: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
+[8]: https://opensource.com/article/19/10/programming-bash-loops
+[9]: http://www.both.org/?page_id=1183
diff --git a/sources/tech/20191222 Create a unique Linux experience with the Unix Desktop Environment.md b/sources/tech/20191222 Create a unique Linux experience with the Unix Desktop Environment.md
new file mode 100644
index 0000000000..bf82680c8b
--- /dev/null
+++ b/sources/tech/20191222 Create a unique Linux experience with the Unix Desktop Environment.md
@@ -0,0 +1,179 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Create a unique Linux experience with the Unix Desktop Environment)
+[#]: via: (https://opensource.com/article/19/12/linux-unix-desktop-environment-ude)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Create a unique Linux experience with the Unix Desktop Environment
+======
+This article is part of a special series of 24 days of Linux desktops.
+If you're in the mood for something completely unique, then UDE is the
+desktop you need to try.
+![Penguins][1]
+
+When the UDE project started in 1996, the developers took on a bold name—[Unix Desktop Environment (UDE)][2]—and held high hopes of reinventing what a desktop could be. They weren't just trying to redefine Unix desktops; they were trying to change the way users interacted with applications on their system. Windows 95 had just come out, so the idea of managing a make-believe "desktop" filled with "folders" and "windows" meant to mimic a real-world desktop had not won all computer users' mindshare (it still hasn't, but it does at least seem to be a reliably stable option now). There was still room for experimentation in computer user interfaces (UIs), and the UDE project introduced some truly innovative ideas.
+
+One of UDE's most intriguing concepts is that its windows have no title bars or handles. All window control is performed with a hex menu that appears when a window border is clicked. Windows are moved with a middle-click and resized with a right-click.
+
+![Unix Desktop Environment][3]
+
+If you're in the mood for something completely unique, then UDE is the desktop you need to try.
+
+### Installing UDE
+
+Your distribution probably doesn't have UDE in its software repository, but it's relatively easy to compile for someone who's used to building software from raw source code.
+
+I installed UDE on Slackware 14.2, but it doesn't rely on any libraries other than standard Xlibs, so it should work on any Linux or BSD system. The compile process requires build tools, which ship by default on Slackware but are often omitted on other distributions to save space on the initial download. The names of the packages you must install to build from source code vary depending on your distro, so refer to the documentation for specifics. For example, on Debian-based distributions, you can learn about build requirements in [Debian's BuildingTutorial][4] doc, and on Fedora-based distributions, refer to [Fedora's Installing software from source][5] doc. Once you have the build tools installed, you can build UDE the standard [GNU Automake][6] way:
+
+
+```
+$ ./configure
+$ make -j2
+$ sudo make install
+```
+
+The default location for installation is **/usr/local**, but you can adjust the paths during the configuration step.
+
+### Xinitrc and UDE
+
+The easiest way to get up and running with UDE is to let Xorg do the bulk of the work. First, you must create a **$HOME/.xinitrc** file. I adapted this from scripts bundled in Slackware:
+
+
+```
+#!/bin/sh
+# $XConsortium: xinitrc.cpp,v 1.4 91/08/22 11:41:34 rws Exp $
+
+userresources=$HOME/.Xresources
+usermodmap=$HOME/.Xmodmap
+sysresources=/etc/X11/xinit/.Xresources
+sysmodmap=/etc/X11/xinit/.Xmodmap
+
+# merge in defaults and keymaps
+
+if [ -f $sysresources ]; then
+ xrdb -merge $sysresources
+fi
+
+if [ -f $sysmodmap ]; then
+ xmodmap $sysmodmap
+fi
+
+if [ -f $userresources ]; then
+ xrdb -merge $userresources
+fi
+
+if [ -f $usermodmap ]; then
+ xmodmap $usermodmap
+fi
+
+# window manager
+exec /usr/local/bin/uwm
+```
+
+According to this file, the default action for the **startx** command is to launch the **uwm** window manager (which houses UDE). However, your distribution may have other ideas about what happens when your graphic server is launched (or killed to be restarted), so this file may do you little good. On many distributions, you can add a **.desktop** file to **/usr/share/xsessions** to have it listed in the GDM or KDM menu, so create a file called **uwm.desktop** and enter this text:
+
+
+```
+[Desktop Entry]
+Name=UDE
+Comment=UNIX Desktop Environment
+Exec=/usr/local/bin/uwm
+Type=Application
+```
+
+Log out from your desktop session and log back into UDE. By default, your session manager (KDM, GDM, or LightDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+With GDM:
+
+![][7]
+
+With SDDM:
+
+![][8]
+
+#### Launching with brute force
+
+If UDE fails to start, try installing XDM, a lightweight session manager that doesn't look at **/usr/share/xsessions** and instead just does whatever the authenticated user's **.xinitrc** prescribes.
+
+### Desktop tour
+
+When UDE first launches, you may find yourself staring at a black screen. That's the default primary desktop for UDE, and it's blank because no background wallpaper has been set. You can set one for yourself with the **feh** command (you may need to install it from your repository). This command has a few options for setting the background, including **\--bg-fill** to fill the screen with your wallpaper of choice, **\--bg-scale** to scale it to fit, and so on.
+
+
+```
+`$ feh --bg-fill ~/Pictures/wallpapers/mybackground.jpg`
+```
+
+### Interacting with the desktop
+
+The next task is to launch an application. UDE provides an application menu, which you can bring up at your mouse pointer's position with a right-click on the desktop. Because you haven't customized the menu yet, your best bet is to launch an **xterm** window so that you can issue arbitrary commands.
+
+Once you have an xterm window open, you might notice that there's no window decoration. This is the central idea behind UDE: windows are manipulated primarily with a "honeycomb" or hex menu that appears when you left-click on the border of any window.
+
+![UDE honeycomb menu][9]
+
+Clockwise from the top hex, the options are:
+
+ * Close
+ * Kill (confirm by selecting the pop-up hex that appears upon mouseover)
+ * Make sticky or send to a different desktop
+ * Maximize
+ * Send behind other windows
+ * Minimize
+
+
+
+Most of them are self-explanatory, but the minimize option can be confusing because there's no place for windows to be minimized _to_ because there's no taskbar, no docklet, and no desktop icons. To retrieve a minimized window, middle-click on the desktop.
+
+![UDE middle-click menu][10]
+
+This presents a menu of virtual desktops, one of which is your current desktop and therefore contains even your minimized applications. Select the minimized application to restore it to your screen.
+
+### Menus and configuration
+
+There are example and default config files in **/usr/local/share/uwm/config**, including one for the right-click application menu configuration. The syntax for the menu is simple and well-documented at the top of the file. This code sample changes the browser option from Netscape to Firefox:
+
+
+```
+LINE;
+% ITEM "Netscape":"netscape";
+ITEM "Firefox":"firefox";
+LINE;
+```
+
+To see your changes, restart UDE from the left-click menu. The **uwmrc** configuration files dictate the layout of UDE, including the size of window borders, fonts, and other stylistic choices. They are
+
+also well-documented in comments, so look through them and make changes to experiment and find what works best for you.
+
+### Old innovations, new again
+
+UDE's interface is strange and new and—if you're intrigued by UI design—very exciting. UDE's design exemplifies the advantages and disadvantages of creating standards in computing. On the one hand, something like UDE is so alien to most users that it's bound to get in the way, yet on the other hand, it's fresh and different and forces users to re-evaluate their workflows, which may result in several unexpected improvements. The reaction you probably have when trying UDE is the same one you're likely to see when you introduce a friend to Linux: What's an old, familiar GNOME or KDE desktop to you is a puzzle to them. But deep down, most of us know the potential benefits of changing the way we look at something we take for granted.
+
+That said, UDE is unquestionably an experiment, not a finished project. It probably isn't going to be your primary desktop, but it's well worth exploring. This is innovation. It's sometimes messy, sometimes slow, sometimes tumultuous. But it's important, bold, and a heck of a lot of fun.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-unix-desktop-environment-ude
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/linux-penguins.png?itok=yKOpaJM_ (Penguins)
+[2]: http://udeproject.sourceforge.net/
+[3]: https://opensource.com/sites/default/files/uploads/advent-ude.jpg (Unix Desktop Environment)
+[4]: https://wiki.debian.org/BuildingTutorial
+[5]: https://docs.pagure.org/docs-fedora/installing-software-from-source.html
+[6]: https://opensource.com/article/19/7/introduction-gnu-autotools
+[7]: https://opensource.com/sites/default/files/advent-gdm_2.jpg
+[8]: https://opensource.com/sites/default/files/advent-kdm_1.jpg
+[9]: https://opensource.com/sites/default/files/uploads/advent-ude-hex.jpg (UDE honeycomb menu)
+[10]: https://opensource.com/sites/default/files/uploads/advent-ude-middle.jpg (UDE middle-click menu)
diff --git a/sources/tech/20191223 10 articles to learn Linux your way.md b/sources/tech/20191223 10 articles to learn Linux your way.md
new file mode 100644
index 0000000000..0ef668ad28
--- /dev/null
+++ b/sources/tech/20191223 10 articles to learn Linux your way.md
@@ -0,0 +1,96 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (10 articles to learn Linux your way)
+[#]: via: (https://opensource.com/article/19/12/learn-linux)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+10 articles to learn Linux your way
+======
+It's been a good year for Linux, so take a look back at the top 10 Linux
+articles on Opensource.com from 2019.
+![Penguins gathered together in the Artic][1]
+
+The year 2019 has been good for Linux with Opensource.com readers. Obviously, the term "Linux" itself is weighted: Does it refer to the kernel or the desktop or the ecosystem? In this look back at the top Linux articles of the year, I've intentionally taken a broad view in defining the top 10 Linux articles (for some definition of "top" and some definition of "Linux"). Here they are, offered in no particular order.
+
+### A beginner's guide to Linux permissions
+
+[_A beginner's guide to Linux permissions_][2] by Bryant Son introduces new users to the concept of file permissions with graphics and charts to illustrate each point. It can be hard to come up with visuals for concepts that are, at their core, purely text-based, and this article is friendly for the visual learners out there. I also like how Bryant stays focused. Any discussion of file permissions can lead to several related topics (like ownership and access control lists and so on), but this article is dedicated to explaining one thing and explaining it well.
+
+### Why I made the switch from Mac to Linux
+
+Matthew Broberg offers an insightful and honest look at his migration to Linux from MacOS in [_Why I made the switch from Mac to Linux_][3]. Changing platforms is always tough, and it's important to record what's behind the decision to switch. Matt's article, I think, serves several purposes, but the two most important for me: it's an invitation for the Linux community to support him by answering questions and offering potential solutions, and it's a good data point for others who are considering Linux adoption.
+
+### Troubleshooting slow WiFi on Linux
+
+In [_Troubleshooting slow WiFi on Linux_][4], David Clinton provides a useful analysis of a problem everyone has on every platform—and has tips on how to solve it. It's a good example of an "incidentally Linux" tip that not only helps everyday people with everyday problems but also shows non-Linux users how approachable troubleshooting (on any platform) is.
+
+### How GNOME uses Git
+
+[_How GNOME uses Git_][5] by Molly de Blanc takes a look behind the scenes, revealing how one of the paragons of open source software (the GNOME desktop) uses one of the other paragons of open source (Git) for development. It's always heartening to me to hear about an open source project that defaults to an open source solution for whatever needs to be done. Believe it or not, this isn't always the case, but for GNOME, it's an important and welcoming part of the project's identity.
+
+### Virtual filesystems in Linux: Why we need them and how they work
+
+Alison Chaiken masterfully explains what is considered incomprehensible to many users in [_Virtual filesystems in Linux: Why we need them and how they work_][6]. Understanding what a filesystem is and what it does is one thing, but _virtual_ ones aren't even, by definition, real. And yet Linux delivers them in a way that even casual users can benefit from, and Alison's article explains it in a way that anyone can understand. As a bonus, Alison goes even deeper in the second half of the article and demonstrates how to use bcc scripts to monitor everything she just taught you.
+
+### Understanding file paths and how to use them
+
+I thought [_Understanding file paths and how to use them_][7] was important to write about because it's a concept most users (on any platform) don't seem to be taught. It's a strange phenomenon, because now, more than ever, the _file path_ is something people see literally on a daily basis: Nearly all internet URLs contain a file path telling you exactly where within the domain you are. I often wonder why computer education doesn't start with the internet, the most familiar app of all and arguably the most heavily used supercomputer in existence, and use it to explain the appliances we interface with each day. (I guess it would help if those appliances were running Linux, but we're working on that.)
+
+### Inter-process communication in Linux
+
+[_Inter-process communication in Linux: Shared storage_][8] by Marty Kalin delves into the developer side of Linux, explaining IPC and how to interact with it in your code. I'm cheating by including this article because it's actually a three-part series, but it's the best explanation of its kind. There is very little documentation that manages to explain how Linux handles IPC, much less what IPC is, why it's important, or how to take advantage of it when programming. It's normally a topic you work your way up to in university. Now you can read all about it here instead.
+
+### Understanding system calls on Linux with strace
+
+[_Understanding system calls on Linux with strace_][9] by Gaurav Kamathe is highly technical in ways I wish that every conference talk I've ever seen about **strace** was. This is a clear and helpful demonstration of a complex but amazingly useful command. To my surprise, the command I've found myself using since this article isn't the titular command, but **ltrace** (to see which functions are called by a command). Obviously, this article's packed with information and is a handy reference for developers and QA testers.
+
+### How the Linux desktop has grown
+
+[_How the Linux desktop has grown_][10] by Jim Hall is a visual journey through the history of the Linux desktop. It starts with [TWM][11] and passes by [FVWM][12], [GNOME][13], [KDE][14], and others. If you're new to Linux, this is a fascinating history lesson from someone who was there (and has the screenshots to prove it). If you've been with Linux for many years, then this will definitely bring back memories. In the end, though, one thing is certain: Anyone who can still locate screenshots from 20 years ago is a superhuman data archivist.
+
+### Create your own video streaming server with Linux
+
+[_Create your own video streaming server with Linux_][15] by Aaron J. Prisk breaks down more than just a few preconceptions most of us have about the services we take for granted. Because services like YouTube and Twitch exist, many people assume that those are the only gateways to broadcasting video to the world. Of course, people used to think that Windows and Mac were the only gateways into computing, and that, thankfully, turned out to be a gross miscalculation. In this article, Aaron sets up a video-streaming server and even manages to find space to talk about [OBS][16] in so you can create videos to stream. Is it a fun weekend project or the start of a new career? You decide.
+
+### 10 moments that shaped Linux history
+
+[_10 moments that shaped Linux history_][17] by Alan Formy-Duval attempts the formidable task of choosing just 10 things to highlight in the history of Linux. It's an exercise in futility, of course, because there have been so many important moments, so I love how Alan filters it through his own experience. For example, when was it obvious that Linux was going to last? When Alan realized that all the systems he maintained at work were running Linux. There's a beauty to interpreting history this way because the moments of importance will differ for each person. There's no definitive list for Linux, or articles about Linux, or for open source. You make your own list, and you make yourself a part of it.
+
+### What do you want to learn?
+
+What else do you want to know about Linux? Please tell us about it in the comments, or [write an article][18] for Opensource.com about your experience with Linux.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/learn-linux
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/OSDC_Penguin_Image_520x292_12324207_0714_mm_v1a.png?itok=p7cWyQv9 (Penguins gathered together in the Artic)
+[2]: https://opensource.com/article/19/6/understanding-linux-permissions
+[3]: https://opensource.com/article/19/10/why-switch-mac-linux
+[4]: http://opensource.com/article/19/4/troubleshooting-wifi-linux
+[5]: https://opensource.com/article/19/10/how-gnome-uses-git
+[6]: https://opensource.com/article/19/3/virtual-filesystems-linux
+[7]: https://opensource.com/article/19/8/understanding-file-paths-linux
+[8]: https://opensource.com/article/19/4/interprocess-communication-linux-storage
+[9]: https://opensource.com/article/19/2/linux-backup-solutions
+[10]: https://opensource.com/article/19/8/how-linux-desktop-grown
+[11]: https://github.com/freedesktop/twm
+[12]: http://www.fvwm.org/
+[13]: http://gnome.org
+[14]: http://kde.org
+[15]: https://opensource.com/article/19/1/basic-live-video-streaming-server
+[16]: https://opensource.com/life/15/12/real-time-linux-video-editing-with-obs-studio
+[17]: https://opensource.com/article/19/4/top-moments-linux-history
+[18]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191223 10 resources to become a better Bash user.md b/sources/tech/20191223 10 resources to become a better Bash user.md
new file mode 100644
index 0000000000..b00f359d4d
--- /dev/null
+++ b/sources/tech/20191223 10 resources to become a better Bash user.md
@@ -0,0 +1,77 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (10 resources to become a better Bash user)
+[#]: via: (https://opensource.com/article/19/12/bash-resources)
+[#]: author: (David Both https://opensource.com/users/dboth)
+
+10 resources to become a better Bash user
+======
+Take a look through our top 10 Bash articles from 2019.
+![bash logo on green background][1]
+
+As another great year wraps up at Opensource.com, my fascination with all things [Bash][2] has me looking back at the top 10 Bash articles we published in 2019. These articles include basic how-to articles, tools, shortcuts, and even a way to build your own command-line game with Bash.
+
+I didn't select these articles based solely on the number of hits they had but rather on a number of criteria. In the true spirit of top 10 countdowns, the top Bash article from 2019 is at the end for the final reveal.
+
+ 10. [_Bash vs. Python: Which language should you use?_][3] by Archit Modi looks at the strengths and weaknesses of these popular languages. Although both have many good points, the bottom line—as with most things Linux—is, "it depends."
+
+
+ 9. [_How to program with Bash: Logical operators and shell expansions_][4] is the second in a three-part series I wrote about Bash programming. This article lists all of the Bash logical operators and provides some easy examples for using them. It also discusses five of the seven types of shell expansions and includes easy-to-understand examples that help to clarify how these expansions work.
+
+
+ 8. Abhishek Tamrakar shows us how to _[Hone advanced Bash skills by building Minesweeper][5]._ This is an interesting, fun, and informative way to improve the Bash skills you already have. When finished, you have a working command-line game of Minesweeper and some serious skills. This article is one of my favorites because it not only stretches our skills, but it illustrates the power of Bash as a programming language.
+
+
+ 7. [_How to program with Bash: Syntax and tools_][6] is the first article in my Bash programming series. In addition to introducing Bash as a programming language, it looks at the basic syntax of Bash programming, the use of variables, and flow control.
+
+
+ 6. Matthew Broberg's [_The birth of the Bash shell_][7] delves into the history of the Bash shell with a look at how it all started with Unix and the original (Ken) Thompson shell. As someone who appreciates the historical roots of Linux and many of its components, I gained some new insights from this article.
+
+
+ 5. Seth Kenlon contributed _[How to write a loop in Bash][8],_ which explores the _for_ loop in some detail. A _for_ loop is a recipe detailing what actions you want your computer to take for each data object (such as a file) you specify. This article has some excellent examples to get you started and shows the power that loops can bring to Bash scripts.
+
+
+ 4. _[7 Bash history shortcuts you will actually use][9]_ shows how to save time on the command line by using Bash shortcuts. Ian Miell describes time-saving tools that go far beyond just simple command-line recall. These are very cool, and I especially like the easy method for reissuing the previous command while reordering the arguments.
+
+
+ 3. Seth Kenlon also shows some [_Bash aliases you can't live without_][10] that will save even more time. This article takes us through one of the ways that we "lazy sysadmins" can become even more efficient than we already are. This is all about less typing while getting more results.
+
+
+ 2. I always recommend testing scripts to ensure that they do what they are intended to—and that they don't create any other problems while doing so. Darin London introduces us to _[Testing Bash with BATS][11],_ the Bash Automated Testing System, a TAP-compliant testing framework for Bash. The [Test Anything Protocol][12] is also used for testing many other Unix languages. This article is loaded with examples and recommendations for structuring Bash programs so that they can be tested easily with this tool.
+
+
+ 1. Our number 1 spot for 2019 is—drum-roll—Seth Kenlon with [_3 command line games for learning Bash the fun way_][13]. Learning is work, but it can be fun. If you are into games (and it seems that we sysadmins like to have fun), this article looks at three tools for learning more about Bash for everyone from noobs to gurus. Everything you do in the game of Bashcrawl, for example, is a valid Bash command that you can use later in real life, and playing the game provides Bash practice because the "game" is made out of actual directories and files on your computer.
+
+
+
+These articles can help you learn Bash and some of its many powerful features. I have certainly learned a lot from them.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/bash-resources
+
+作者：[David Both][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/dboth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/bash_command_line.png?itok=k4z94W2U (bash logo on green background)
+[2]: https://opensource.com/downloads/bash-cheat-sheet
+[3]: https://opensource.com/article/19/4/bash-vs-python
+[4]: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
+[5]: https://opensource.com/article/19/9/advanced-bash-building-minesweeper
+[6]: https://opensource.com/article/19/10/programming-bash-syntax-tools
+[7]: https://opensource.com/19/9/command-line-heroes-bash
+[8]: https://opensource.com/article/19/6/how-write-loop-bash
+[9]: https://opensource.com/article/19/10/bash-history-shortcuts
+[10]: https://opensource.com/article/19/7/bash-aliases
+[11]: https://opensource.com/article/19/2/testing-bash-bats
+[12]: https://testanything.org/producers.html
+[13]: https://opensource.com/article/19/10/learn-bash-command-line-games
diff --git a/sources/tech/20191223 Best of 2019- Fedora for system administrators.md b/sources/tech/20191223 Best of 2019- Fedora for system administrators.md
new file mode 100644
index 0000000000..5e57ff2912
--- /dev/null
+++ b/sources/tech/20191223 Best of 2019- Fedora for system administrators.md
@@ -0,0 +1,70 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Best of 2019: Fedora for system administrators)
+[#]: via: (https://fedoramagazine.org/best-of-2019-fedora-for-system-administrators/)
+[#]: author: (Paul W. Frields https://fedoramagazine.org/author/pfrields/)
+
+Best of 2019: Fedora for system administrators
+======
+
+![][1]
+
+The end of the year is a perfect time to look back on some of the Magazine’s most popular articles of 2019. One of the Fedora operating systems’s many strong points is its wide array of tools for system administrators. As your skills progress, you’ll find that the Fedora OS has even more to offer. And because Linux is the sysadmin’s best friend, you’ll always be in good company. In 2019, there were quite a few articles about sysadmin tools our readers enjoyed. Here’s a sampling.
+
+### Introducing Fedora CoreOS
+
+If you follow modern IT topics, you know that containers are a hot topic — and [containers mean Linux][2]. This summer brought the first preview release of [Fedora CoreOS][3]. This new edition of Fedora can run containerized workloads. You can use it to deploy apps and services in a modern way.
+
+> [Introducing Fedora CoreOS][4]
+
+### InitRAMFS, dracut and the dracut emergency shell
+
+To be a good sysadmin, you need to understand system startup and the boot process. From time to time, you’ll encounter software errors, configuration problems, or other issues that keep your system from starting normally. With the information in the article below, you can do some life-saving surgery on your system, and restore it to working order.
+
+> [InitRAMFS, Dracut, and the Dracut Emergency Shell][5]
+
+### How to reset your root password
+
+Although this article was published a few years ago, it continues to be one of the most popular. Apparently, we’re not the only people who sometimes get locked out of our own system! If this happens to you, and you need to reset the root password, the article below should do the trick.
+
+> [How to reset a root password on Fedora][6]
+
+### Systemd: unit dependencies and order
+
+This article is part of [an entire series][7] on systemd, the modern system and process manager in Fedora and other distributions. As you may know, systemd has sophisticated but easy to use methods to start up or shut own services in the right order. This article shows you how they work. That way you can apply the right options to unit files you create for systemd.
+
+> [systemd: Unit dependencies and order][8]
+
+### Setting kernel command line arguments
+
+Fedora 30 introduced new ways to change the boot options for your kernel. This article from Laura Abbott on the Fedora kernel team explains the new Bootloader Spec (BLS). It also tells you how to use it to set options on your kernel for boot time.
+
+> [Setting kernel command line arguments with Fedora 30][9]
+
+Stay tuned to the Magazine for other upcoming “Best of 2019” categories. All of us at the Magazine hope you have a great end of year and holiday season.
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/best-of-2019-fedora-for-system-administrators/
+
+作者：[Paul W. Frields][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/pfrields/
+[b]: https://github.com/lujun9972
+[1]: https://fedoramagazine.org/wp-content/uploads/2019/12/2019top-sysadmins.png-816x345.jpg
+[2]: https://www.redhat.com/en/blog/containers-are-linux
+[3]: https://getfedora.org/coreos/
+[4]: https://fedoramagazine.org/introducing-fedora-coreos/
+[5]: https://fedoramagazine.org/initramfs-dracut-and-the-dracut-emergency-shell/
+[6]: https://fedoramagazine.org/reset-root-password-fedora/
+[7]: https://fedoramagazine.org/series/systemd-series/
+[8]: https://fedoramagazine.org/systemd-unit-dependencies-and-order/
+[9]: https://fedoramagazine.org/setting-kernel-command-line-arguments-with-fedora-30/
diff --git a/sources/tech/20191223 Get back to basics with the TWM Linux desktop.md b/sources/tech/20191223 Get back to basics with the TWM Linux desktop.md
new file mode 100644
index 0000000000..19b16daf6f
--- /dev/null
+++ b/sources/tech/20191223 Get back to basics with the TWM Linux desktop.md
@@ -0,0 +1,109 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Get back to basics with the TWM Linux desktop)
+[#]: via: (https://opensource.com/article/19/12/twm-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Get back to basics with the TWM Linux desktop
+======
+This article is part of a special series of 24 days of Linux desktops.
+TWM may be bare-bones by default, but it's a great foundation for a
+customized Linux desktop that has all your favorite bits and pieces.
+![Penguin driving a car with a yellow background][1]
+
+The most humble of window managers, TWM, is a little akin to those sample photographs you get when you buy a picture frame. It's basic, almost a bare-minimum proof of concept that Xorg ships with the [X11][2] Windows System to demonstrate that a desktop can indeed be created for a graphical user interface (GUI).
+
+Some distributions treat it as a fallback window manager that can be launched in a pinch if you break your usual desktop and need a terminal just long enough for repairs. Now that Xorg is basically bulletproof and moving aside for [Wayland][3], sometimes TWM isn't even included at all. And yet, amazingly, TWM, short for either _Timeless Window Manager_ or _Tabbed Window Manager_, depending on who you ask, has some fun features and configuration options.
+
+![TWM][4]
+
+Your distribution (XQuartz on Mac OS included) may discreetly include TWM as a fallback window manager. Otherwise, you are likely to find it in your software repository, and you can also get it from the [Freedesktop][5] GitHub repository. If you're already running a different desktop, it's safe to install TWM on the same system because it doesn't include any bundled applications aside from a few configuration panels.
+
+After installing, log out of your current desktop session so you can log into TWM. By default, your session manager (KDM, GDM, LightDM, or XDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging into your new one.
+
+With GDM:
+
+![Selecting your desktop in GDM][6]
+
+With SDDM:
+
+![Selecting your desktop in KDM][7]
+
+### Desktop tour
+
+TWM's basic configuration is usually unspectacular. Here's TWM on my Slackware system:
+
+![TWM by default][8]
+
+You can get a pop-up menu with a left-click on the desktop. By default, it has one application listed: xterm. When you launch xterm, the outline of a window appears until you click to place it on the desktop.
+
+More actions are available with a right-click or a middle-click on the desktop or a window's title bar. For instance, to resize a window, you can middle-click the title bar and select **Resize**; this places you into resize mode so you can drag your mouse across the edge of the window you want to make smaller or larger. Click again to confirm the new size.
+
+When you right-click the icon in the upper-left corner of any window, that window is minimized into a desktop icon (a precursor to the OS X dock). You can drag this icon anywhere on your desktop and right-click on it to restore it back to a full-sized window.
+
+These are all old Unix conventions; tricks of the visual interface that long-time Unix users will remember fondly but are utterly baffling at first to new users. You can learn to love them by using TWM, but if you do that, you'll no doubt want something a little prettier and more tailored to your daily workflow.
+
+### TWM configuration
+
+One of my favorite sites is [Linux Questions][9], a tried-and-true Linux support forum. I stumbled across a post there about TWM, where user **rkfb** was, apparently in all seriousness, praising TWM as his favorite lightweight window manager. What's more, **rkfb** had [the config file to prove it][10].
+
+I downloaded the sample **.twmrc** file and discovered that there are a surprising number of options and features in TWM. Like other "building-block" window managers, such as [FVWM][11] or [MLVWM][12], it takes a lot of work to customize it and bring it up to modern expectations. You can also add the usual laundry list of applications to TWM. For instance, you could run [Tint2][13] or [Xfce-panel][14] to provide a traditional taskbar and other applets, or [stalonetray][15] for a system tray, and [vdesk][16] to provide virtual desktops, but then again, TWM isn't meant to be a _modern_ window manager, but a _timeless_ window manager. You may not want to make it too modern.
+
+There are _lots_ of options and definitions in the config file for TWM. Two of my favorites are **RandomPlacement** (an option to activate random placement of windows, so you don't have to manually click to set the location of each window you launch) and **ShowIconManager** (which displays a vertical taskbar).
+
+The syntax to define the contents of the menus is pretty easy to understand:
+
+
+```
+menu "Shells" {
+ "Shells" f.title
+ "rxvt" f.exec "urxvt -fg cyan -bg black -cr white &"
+ "Konsole" f.exec "konsole &"
+}
+```
+
+Color themes are similarly intuitive from the sample file.
+
+You can set a background using the **feh** command (you probably need to install it first):
+
+
+```
+`$ feh --bg-fill ~/christopher-burns_unsplash.jpg`
+```
+
+### Old TWM is new TWM
+
+TWM looks and feels like an artifact of a bygone era, when desktops were simpler in design but complex in configuration. It's probably not the best or the most flexible window manager available, but it's surprisingly configurable. You can use it as the foundation of a customized desktop consisting of all your favorite desktop bits and pieces. You can spend the time to make TWM something you enjoy using, and you'll learn a lot about interface design, Unix history, and pixmap bit depth along the way. Give TWM another look, and make that look beautiful.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/twm-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/car-penguin-drive-linux-yellow.png?itok=twWGlYAc (Penguin driving a car with a yellow background)
+[2]: https://en.wikipedia.org/wiki/X_Window_System
+[3]: https://wayland.freedesktop.org/
+[4]: https://opensource.com/sites/default/files/uploads/advent-twm.jpg (TWM)
+[5]: https://github.com/freedesktop/twm
+[6]: https://opensource.com/sites/default/files/uploads/advent-gdm_3.jpg (Selecting your desktop in GDM)
+[7]: https://opensource.com/sites/default/files/uploads/advent-kdm_2.jpg (Selecting your desktop in KDM)
+[8]: https://opensource.com/sites/default/files/uploads/advent-twm-basic.jpg (TWM by default)
+[9]: http://linuxquestions.org
+[10]: https://www.linuxquestions.org/questions/linux-desktop-74/share-your-configuration-file-of-twm-best-x-windows-manager-4175585974
+[11]: https://opensource.com/article/19/12/fvwm-linux-desktop
+[12]: https://opensource.com/article/19/12/linux-mlvwm-desktop
+[13]: https://opensource.com/article/19/1/productivity-tool-tint2
+[14]: https://opensource.com/article/19/12/xfce-linux-desktop
+[15]: http://stalonetray.sourceforge.net/
+[16]: https://offog.org/code/vdesk
diff --git a/sources/tech/20191223 Prioritizing simplicity in your Python code.md b/sources/tech/20191223 Prioritizing simplicity in your Python code.md
new file mode 100644
index 0000000000..53662a8f1c
--- /dev/null
+++ b/sources/tech/20191223 Prioritizing simplicity in your Python code.md
@@ -0,0 +1,59 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Prioritizing simplicity in your Python code)
+[#]: via: (https://opensource.com/article/19/12/zen-python-simplicity-complexity)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+Prioritizing simplicity in your Python code
+======
+This is the second part of a special series about the Zen of Python
+focusing on the third and fourth principles: simplicity and complexity.
+![Person reading a book and digital copy][1]
+
+> "Il semble que la perfection soit atteinte non quand il n'y a plus rien à ajouter, mais quand il n'y plus rien à retrancher."
+>
+> "It seems that perfection is finally attained not when there is no longer anything to add, but when there is no longer anything to take away."
+> —Antoine de Saint-Exupéry, _[Terre des Hommes][2]_, 1939
+
+A common concern in programming is the struggle with complexity. It is easy for any programmer to make a program so complicated no expert can debug it or modify it. The [Zen of Python][3] would not be complete if it did not touch on this.
+
+### Simple is better than complex.
+
+When it is possible to choose at all, choose the simple solution. Python is rarely in the business of _disallowing_ things. This means it is possible, and even straightforward, to design baroque programs to solve straightforward problems.
+
+It is worthwhile to remember at each point that simplicity is one of the easiest things to lose and the hardest to regain when writing code.
+
+This can mean choosing to write something as a function, rather than introducing an extraneous class. This can mean avoiding a robust third-party library in favor of writing a two-line function that is perfect for the immediate use-case. Most often, it means avoiding predicting the future in favor of solving the problem at hand.
+
+It is much easier to change the program later, especially if simplicity and beauty were among its guiding principles than to load the code down with all possible future variations.
+
+### Complex is better than complicated.
+
+This is possibly the most misunderstood principle because understanding the precise meanings of the words is crucial. Something is _complex_ when it is composed of multiple parts. Something is _complicated_ when it has a lot of different, often hard to predict, behaviors.
+
+When solving a hard problem, it is often the case that no simple solution will do. In that case, the most Pythonic strategy is to go "bottom-up." Build simple tools and combine them to solve the problem.
+
+This is where techniques like _object composition_ shine. Instead of having a complicated inheritance hierarchy, have objects that forward some method calls to a separate object. Each of those can be tested and developed separately and then finally put together.
+
+Another example of "building up" is using [singledispatch][4], so that instead of one complicated object, we have a simple, mostly behavior-less object and separate behaviors.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/zen-python-simplicity-complexity
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/read_book_guide_tutorial_teacher_student_apaper.png?itok=_GOufk6N (Person reading a book and digital copy)
+[2]: https://en.wikipedia.org/wiki/Wind,_Sand_and_Stars
+[3]: https://www.python.org/dev/peps/pep-0020/
+[4]: https://opensource.com/article/19/5/python-singledispatch
diff --git a/sources/tech/20191224 Chill out with the Linux Equinox Desktop Environment.md b/sources/tech/20191224 Chill out with the Linux Equinox Desktop Environment.md
new file mode 100644
index 0000000000..59abeb92b8
--- /dev/null
+++ b/sources/tech/20191224 Chill out with the Linux Equinox Desktop Environment.md
@@ -0,0 +1,95 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Chill out with the Linux Equinox Desktop Environment)
+[#]: via: (https://opensource.com/article/19/12/ede-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+Chill out with the Linux Equinox Desktop Environment
+======
+This article is part of a special series of 24 days of Linux desktops.
+EDE is not the most glamorous, minimal, nor efficient desktop. But its
+soft, muted tones are calming, its familiarity soothing, and its icon
+theme fun.
+![Linux penguin at the north pole beside an igloo][1]
+
+I haven't used the Fast Light Toolkit ([FLTK][2]) for anything serious yet, but I'm a fan of the C++ GUI toolkit that's pretty simple to learn and (in my experience) reliable even across updates. When I found out that there was a desktop environment built with FLTK, I was eager to try it—and I was quickly glad I did. The [Equinox Desktop Environment (EDE)][3] is a fast and simple desktop written in C++ and FLTK for Unix desktops. It uses common desktop conventions, so it looks and feels familiar right away, and after only a few days of using it, I found its simplicity provides a minimal elegance that I enjoy.
+
+![EDE desktop][4]
+
+### Installing EDE
+
+You are likely to find EDE included in your distribution's software repository, but you can also find it in its [SourceForge repository][5]. If you're already running a different desktop, it's safe to install EDE on the same system because it brings along just a few extra applications, which are specific to EDE so they won't get in your way on other desktops.
+
+EDE is only the desktop, and it uses the [Pekwm][6] window manager to handle layout.
+
+After installing EDE, log out of your current desktop session so you can log into your new one. By default, your session manager (KDM, GDM, LightDM, or XDM, depending on your setup) will continue to log you into your previous desktop, so you must override that before logging in.
+
+With GDM:
+
+![][7]
+
+With SDDM:
+
+![][8]
+
+When EDE first boots, you might be prompted to confirm some startup tasks. On my Slackware workstation, KDE had marked some services as startup tasks (such as the HPLIP print monitor and a Bluetooth daemon), and EDE imported them with just one confirmation box.
+
+![Importing desktop services in EDE][9]
+
+After setting it up once, you won't need to do it again.
+
+### EDE desktop tour
+
+EDE's layout is exactly what most people expect from a desktop: application menu on the left, taskbar in the middle, system tray on the right. It's the standard off-the-shelf layout that confuses nobody; this is a desktop that's safe to install on a Linux computer and hand over, with confidence, to someone who's never used Linux in their life. They'll fall right into this desktop with a soft and gentle landing.
+
+You can bring up a small desktop menu with a right-click. This allows you to make an application launcher on the desktop, create a folder, and set some theme options.
+
+The panel at the bottom of the screen is retractable, so you can work full-screen if you prefer. Click the clock in the bottom-right of the screen to bring up a calendar and time-zone settings.
+
+EDE has a small Configuration Place application that provides access to a few simple preferences:
+
+ * Background and icon settings
+ * Screensaver settings
+ * Time and clock
+ * System bell
+ * Keyboard
+ * Preferred applications
+
+
+
+![EDE Configuration Place][10]
+
+There's not much more to EDE. There's no file manager, no text editor, or paint program, or game of solitaire. You must bring anything you want to run on your desktop. That means you get to pick and choose from the wide array of Linux applications and use whatever you love the most.
+
+### EDE as a statement
+
+I found the simplicity of EDE oddly comforting, at least as a kind of "holiday" desktop; it's a nice place to visit. It's not the most glamorous desktop available, nor the most minimal, nor the most efficient. But its soft, muted tones are calming, its familiarity soothing, and its icon theme fun and exuberant. EDE is a desktop that's proud of its slow and steady pace.
+
+If you're in the mood to put your feet up and enjoy a clean and pleasant interface, try EDE.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/ede-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/penguin.igloo_.png?itok=K92O7H6b (Linux penguin at the north pole beside an igloo)
+[2]: https://www.fltk.org/
+[3]: https://sourceforge.net/projects/ede/
+[4]: https://opensource.com/sites/default/files/uploads/advent-ede.jpg (EDE desktop)
+[5]: http://ede.sf.net
+[6]: https://opensource.com/article/19/12/pekwm-linux-desktop
+[7]: https://opensource.com/sites/default/files/advent-gdm_2.jpg
+[8]: https://opensource.com/sites/default/files/advent-kdm_1.jpg
+[9]: https://opensource.com/sites/default/files/uploads/advent-ede-init.jpg (Importing desktop services in EDE)
+[10]: https://opensource.com/sites/default/files/uploads/advent-ede-conf.jpg (EDE Configuration Place)
diff --git a/sources/tech/20191224 Top articles for learning Python in 2020.md b/sources/tech/20191224 Top articles for learning Python in 2020.md
new file mode 100644
index 0000000000..3b0ba8b166
--- /dev/null
+++ b/sources/tech/20191224 Top articles for learning Python in 2020.md
@@ -0,0 +1,72 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Top articles for learning Python in 2020)
+[#]: via: (https://opensource.com/article/19/12/learn-python)
+[#]: author: (Matthew Broberg https://opensource.com/users/mbbroberg)
+
+Top articles for learning Python in 2020
+======
+No matter where you are in your Python programming journey,
+Opensource.com's top Python articles from 2019 will help you along the
+way.
+![Hands on a keyboard with a Python book ][1]
+
+Python had a big year in 2019. According to popular resources like [GitHub][2] and [Stack Overflow][3], it's trending as the second most popular language in the world.
+
+> "Python, the fastest-growing major programming language, has risen in the ranks of programming languages in our survey yet again, edging out Java this year and standing as the second most loved language (behind Rust)."
+> — [Stack Overflow Insights][3]
+
+Similarly, Python grew in readership on Opensource.com by leaps and bounds. Here are the top Python articles from 2019, grouped by topic, for your perusal.
+
+### Why choose Python?
+
+There are many languages out there, so what makes Python such a destination? If the most-read articles tell us anything, it's that people enjoy its flexibility. There are [multiple paradigms][4] that are accessible to Python developers, as Jigyasa Grover explains, including the popular [object-oriented programming][5] Seth Kenlon's tutorial shows.
+
+If you're a long-time user and looking for advanced examples of why Python is a perfect language, Moshe Zadka covers his [top 5 reasons for loving Python][6]. If that's not enough, you can also use it play around with powerful tools without a lot of code, like in Parul Pandey's tutorial on [image manipulation][7].
+
+### Configuring Python
+
+As Python's popularity continues to rise, more people are starting with the language than ever before. Many of those first-timers are doing so on the Mac operating system and are using a [guide to setting up Python 3][8] that Moshe and I wrote.
+
+After installing Python, decisions on where to write your code come next. There are many options when it comes to text editors and integrated development environments (IDEs), but readers appear to favor graphical options, as Stephan Avenwedde's article about [Pythonic][9] and my article on [JupyterLab][10] were the most read articles on that topic in 2019.
+
+On the path to getting confident with the language, developers will have to face the multitude of options available for how to manage versions of the language and project dependencies. Luckily, László Kiss Kollár's article makes [managing Python packages][11] a bit simpler.
+
+When you're ready to configure an IDE with all of the features you'll want to make the most of the language, be sure to give the [opinionated linter Black][12] a try, as Moshe explains, to keep your code clean.
+
+### Wrapping up
+
+No matter where you are in your path to enjoying Python programming, the top Python articles from 2019 are here to help you along the way. I can't wrap this up without at least one acknowledgment of the importance of testing, and Moshe offers another well-read article [on tox][13] for that purpose.
+
+Thank you to all the authors who wrote for Opensource.com in 2019! If you're just learning to program in Python, let us know in the comments what you want to know. And, if you're a seasoned veteran, consider sharing your tips and tricks with us by [writing an article][14] about your favorite Python topic.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/learn-python
+
+作者：[Matthew Broberg][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/mbbroberg
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/python-programming-code-keyboard.png?itok=fxiSpmnd (Hands on a keyboard with a Python book )
+[2]: https://octoverse.github.com/#top-languages
+[3]: https://insights.stackoverflow.com/survey/2019
+[4]: https://opensource.com/article/19/10/python-programming-paradigms
+[5]: https://opensource.com/article/19/7/get-modular-python-classes
+[6]: https://opensource.com/article/19/10/why-love-python
+[7]: https://opensource.com/article/19/3/python-image-manipulation-tools
+[8]: https://opensource.com/article/19/5/python-3-default-mac
+[9]: https://opensource.com/article/19/5/graphically-programming-pythonic
+[10]: https://opensource.com/article/19/5/jupyterlab-python-developers-magic
+[11]: https://opensource.com/article/19/4/managing-python-packages
+[12]: https://opensource.com/article/19/5/python-black
+[13]: https://opensource.com/article/19/5/python-tox
+[14]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191224 Why your Python code should be flat and sparse.md b/sources/tech/20191224 Why your Python code should be flat and sparse.md
new file mode 100644
index 0000000000..0e447c5d8e
--- /dev/null
+++ b/sources/tech/20191224 Why your Python code should be flat and sparse.md
@@ -0,0 +1,87 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Why your Python code should be flat and sparse)
+[#]: via: (https://opensource.com/article/19/12/zen-python-flat-sparse)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+Why your Python code should be flat and sparse
+======
+This is part of a special series about the Zen of Python focusing on the
+fifth and sixth principles: flatness and sparseness.
+![Digital creative of a browser on the internet][1]
+
+The [Zen of Python][2] is called that for a reason. It was never supposed to provide easy-to-follow guidelines for programming. The rules are specified tersely and are designed to engage the reader in deep thought.
+
+In order to properly appreciate the Zen of Python, you must read it and then meditate upon the meanings. If the Zen was designed to be a set of clear rules, it would be a fault that it has rules that contradict each other. However, as a tool to help you meditate on the best solution, contradictions are powerful.
+
+### Flat is better than nested.
+
+Nowhere is the pressure to be "flat" more obvious than in Python's strong insistence on indentation. Other languages will often introduce an implementation that "cheats" on the nested structure by reducing indentation requirements. To appreciate this point, let's take a look at JavaScript.
+
+JavaScript is natively async, which means that programmers write code in JavaScript using a lot of callbacks.
+
+
+```
+a(function(resultsFromA) {
+ b(resultsFromA, function(resultsfromB) {
+ c(resultsFromC, function(resultsFromC) {
+ console.log(resultsFromC)
+ }
+ }
+}
+```
+
+Ignoring the code, observe the pattern and the way indentation leads to a right-most point. This distinctive "arrow" shape is tough on the eye to quickly walk through the code, so it's seen as undesirable and even nicknamed "callback hell." However, in JavaScript, it is possible to "cheat" and not have indentation reflect nesting.
+
+
+```
+a(function(resultsFromA) {
+b(resultsFromA,
+ function(resultsfromB) {
+c(resultsFromC,
+ function(resultsFromC) {
+ console.log(resultsFromC)
+}}}
+```
+
+Python affords no such options to cheat: every nesting level in the program must be reflected in the indentation level. So deep nesting in Python _looks_ deeply nested. That makes "callback hell" was a worse problem in Python than in JavaScript: nesting callbacks mean indenting with no options to "cheat" with braces.
+
+This challenge, in combination with the Zen principle, has led to an elegant solution by a library I worked on. In the [Twisted][3] framework, we came up with the _deferred_ abstraction, which would later inspire the popular JavaScript _promise_ abstraction. In this way, Python's unwavering commitment to clear code forces Python developers to discover new, powerful abstractions.
+
+
+```
+future_value = future_result()
+future_value.addCallback(a)
+future_value.addCallback(b)
+future_value.addCallback(c)
+```
+
+(This might look familiar to modern JavaScript programmers: Promises were heavily influenced by Twisted's deferreds.)
+
+### Sparse is better than dense.
+
+The easiest way to make something less dense is to introduce nesting. This habit is why the principle of sparseness follows the previous one: after we have reduced nesting as much as possible, we are often left with _dense_ code or data structures. Density, in this sense, is jamming too much information into a small amount of code, making it difficult to decipher when something goes wrong.
+
+Reducing that denseness requires creative thinking, and there are no simple solutions. The Zen of Python does not offer simple solutions. All it offers are ways to find what can be improved in the code, without always giving guidance for "how."
+
+Take a walk. Take a shower. Smell the flowers. Sit in a lotus position and think hard, until finally, inspiration strikes. When you are finally enlightened, it is time to write the code.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/zen-python-flat-sparse
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/browser_web_internet_website.png?itok=g5B_Bw62 (Digital creative of a browser on the internet)
+[2]: https://www.python.org/dev/peps/pep-0020/
+[3]: https://twistedmatrix.com/trac/
diff --git a/sources/tech/20191225 12 open source resources for kids and young adults.md b/sources/tech/20191225 12 open source resources for kids and young adults.md
new file mode 100644
index 0000000000..48ca3107a4
--- /dev/null
+++ b/sources/tech/20191225 12 open source resources for kids and young adults.md
@@ -0,0 +1,97 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (12 open source resources for kids and young adults)
+[#]: via: (https://opensource.com/article/19/12/kids-students-education)
+[#]: author: (Don Watkins https://opensource.com/users/don-watkins)
+
+12 open source resources for kids and young adults
+======
+Explore new technologies with Opensource.com's top 12 articles from 2019
+about learning an open source technology.
+![Person reading a book and digital copy][1]
+
+Are you looking to challenge your children (or even yourself) to learn new things about open source technologies? Whether you're in elementary school, high school, or college, or even a parent or teacher, Opensource.com has some great reading about open source technologies suitable for the younger generation. Here are our top 12 articles from 2019 on open source for students (and those who love them).
+
+### Hacking math education with Python
+
+As a student, I had difficulty with the abstraction of mathematics. Traditional classroom instruction didn't work for me. Peter Farrell has another approach for learners who are challenged by conventional mathematics instruction. His unique approach, which teaches math using Python, resonated with me when I interviewed him about how he is [_Hacking math education with Python_][2].
+
+### 5 open source tools for teaching young children to read
+
+No doubt, you have seen how easy it is for children to master today's electronic devices—but what about traditional literacy? Are today's children getting the foundation in reading, writing, and arithmetic that they need to be successful? Laura Janusek's [_5 open source tools for teaching young children to read_][3] may help. She says, "Access to literary environments has been shown to impact literacy and attitudes towards reading. Why not strive to create a digital literacy environment for our kids by filling our devices with educational technologies, just like our shelves are filled with books?"
+
+### What programming language would you teach a kid first?
+
+Coding has become a hot area for schools and parents. Opinions abound on the best computer language to teach and when to begin teaching it. Lauren Pritchett celebrated Ada Lovelace Day 2019 by exploring [_What programming language would you teach kids first?_][4] Be sure to take the accompanying poll, too.
+
+### Getting started with the BBC Microbit
+
+Learning to code should be fun, and one of the ways to ensure a great early experience is by using an inexpensive open hardware board. In [_Getting started with the BBC Microbit_][5], I provide step-by-step directions and some code examples so your child can learn to program with MicroPython.
+
+### Introducing kids to computational thinking with Python
+
+Coding can be the key that lifts children out of poverty and empowers them to gain new skills, confidence, and the knowledge necessary to break free from socioeconomic disadvantages. In [_Introducing kids to computational thinking with Python_][6], I interviewed librarian Qumisha Goss, who is leveraging the power of Python to transform children's lives in Detroit.
+
+### A dozen ways to learn Python
+
+Do you know someone who really wants to learn to Python but is looking for the right hook to get started? Removing abstraction has been key to my best learning experiences, and I share some of the resources I've found in [_A dozen ways to learn Python_][7]. They will start you on your journey to Python proficiency and sustain your learning over the long haul.
+
+### 100 ways to learn Python and R for data science
+
+Many people want to learn data science but are drowning in the deluge of information available online, leaving them confused about where to find the best book, tutorial, or other learning resources. Where would you turn to learn the skills necessary to play a role in this rapidly growing field? Chris Englehardt, Dorris Scott, and Annu Singh share their suggestions in [_100 ways to learn Python and_ _R for data science_][8].
+
+### How a trip to China inspired Endless OS and teaching kids to hack
+
+I've long been interested in inexpensive, Linux-based computers that help children around the world learn how to code. One of these is Endless' Hack, a low-cost laptop, and an accompanying series of video games designed to get kids coding and become creative problem solvers while they're having fun. In 2019, I got to interview Endless' founder Matt Dalio, where he shares [_How a trip to China inspired Endless OS and teaching kids to hack_][9].
+
+### How to use the internet to learn IT skills
+
+Looking to do something meaningful in the new year? How about helping a few young people take their first steps in an IT career? You can follow the lead of David Clinton, a systems administrator, teacher, and writer, who shares [_How to use the internet to learn IT skills_][10]. Giving students access to open source tools and letting them explore and iterate creates a rich learning experience, he explains.
+
+### Digital divide? How the Asian Penguins share Linux at Minnesota charter school
+
+Stu Keroff is an educator who has turned his passion for Linux and open source into a school–community outreach program that serves a large number of immigrant families in Minnesota. He is a husband, father, teacher, speaker, and advocate for Linux in K-12 education and a winner of the [2016 Opensource.com Readers Choice Award][11]. In [_Digital divide? How the Asian Penguins share Linux at Minnesota charter school_][12], Stu shares his Linux-powered solution to expand digital literacy in his community.
+
+### 13 books for picking up new tech in 2019
+
+If you (or someone you know) learn best by reading, my [_13 books for picking up new tech in 2019_][13] may help you discover a new skill that piques your curiosity. The list includes books on everything from Python to Linux to developing games on a Raspberry Pi.
+
+### 11 surprising ways you use Linux every day
+
+If you, like me, wonder what powers all the electronic gadgets that power our day-to-day lives today, read my article on [_11 surprising ways you use Linux every day_][14]. You might be amazed at how much we depend on open source to get us through our days.
+
+### A lifetime of learning
+
+What would you like to know to help the children in your life expand their tech knowledge and skills? Please share your ideas in the comments, or even consider sharing your own experiences with Opensource.com readers by [submitting an article][15] about your favorite open source education topic.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/kids-students-education
+
+作者：[Don Watkins][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/don-watkins
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/read_book_guide_tutorial_teacher_student_apaper.png?itok=_GOufk6N (Person reading a book and digital copy)
+[2]: https://opensource.com/article/19/1/hacking-math
+[3]: https://opensource.com/article/19/4/early-literacy-tools
+[4]: https://opensource.com/article/19/10/first-programming-language-kids
+[5]: https://opensource.com/article/19/8/getting-started-bbc-microbit
+[6]: https://opensource.com/article/19/2/break-down-stereotypes-python
+[7]: https://opensource.com/article/19/8/dozen-ways-learn-python
+[8]: https://opensource.com/article/19/5/learn-python-r-data-science
+[9]: https://opensource.com/article/19/6/endless-digital-literacy
+[10]: https://opensource.com/article/19/5/it-skills-internet
+[11]: https://opensource.com/community/16/2/winners-2016-community-awards
+[12]: https://opensource.com/article/19/2/asian-penguins-close-digital-divide
+[13]: https://opensource.com/article/19/1/tech-books-new-skils
+[14]: https://opensource.com/article/19/8/everyday-tech-runs-linux
+[15]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191225 5 security tips from Santa.md b/sources/tech/20191225 5 security tips from Santa.md
new file mode 100644
index 0000000000..1c2f83c02a
--- /dev/null
+++ b/sources/tech/20191225 5 security tips from Santa.md
@@ -0,0 +1,84 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (5 security tips from Santa)
+[#]: via: (https://opensource.com/article/19/12/security-tips)
+[#]: author: (Mike Bursell https://opensource.com/users/mikecamel)
+
+5 security tips from Santa
+======
+Stay off Santa's (and your employer's) naughty list by following this
+list of useful security tips and practices.
+![Security monster][1]
+
+If you're reading this in 2019, it's almost Christmas (as celebrated according to the Western Christian calendar), and, like all children and IT professionals, it's time to write your letter to Santa/St. Nick/Father Christmas. Don't forget: those who have been good get nice presents and those who haven't get coal. Coal is _not_ a clean-burning fuel, and with climate change well and truly upon us,[1][2] you don't want to be going for the latter option.
+
+Think back to all of the good security practices you've adopted over the past 11 or so months. And then think back to all of the bad security practices you've adopted when you should have been doing the _right_ thing. Oh, dear. It's not looking good for you, is it?
+
+Here's the good news, though: because Santa is a benevolent soul, there's time to make amends (unless you're reading this after Christmas[2][3]). Here's a list of useful security tips and practices that Santa follows and therefore are bound to put you on his "good" side.
+
+### 1\. Use a password manager
+
+Santa is very careful with his passwords. Here's a little secret: from time to time, rather than have his elves handcraft every little present, he sources his gifts from other parties. I'm not suggesting that he pays market rates (he's ordering in bulk, and he has a very, very good credit rating), but he uses lots of different suppliers, and he's aware that not all of them take security as seriously as he does. He doesn't want all his account logins to be leaked if one of his suppliers is hacked, so he uses separate passwords for each account. Now, Santa, being Santa, could remember all of these details if he wanted to—and even generate unique passwords that meet all the relevant complexity requirements for each site—but he uses an open source [password manager][4] for safety and for succession planning.[3][5]
+
+### 2\. Manage personal information properly
+
+You may work for a large company, organisation, or government, and you may think you have lots of customers and associated data, but consider Santa. He manages (or has managed) names, birth dates, addresses, hobbies, shoe sizes, colour preferences, and other personal data for literally every person on Earth. That's an awful lot of sensitive data, and it needs to be protected. When people grow too old for presents from Santa,[4][6] he needs to delete their data securely. In fact, Santa may well be the archetypal [GDPR][7] data controller, and he needs to be very careful who and what can access the data that he holds. Of course, he encrypts all the data and is very careful about key management. He's also very aware of the dangers associated with cold boot attacks (given the average temperature around his residence), so he ensures data is properly wiped before shutdown.
+
+### 3\. Measure and mitigate risk
+
+Santa knows all about [risk][8]. He has complex systems for ordering, fulfillment, travel planning, logistics, and delivery that are the envy of most of the world. He understands what impact failure in any part of the supply chain can have on his customers: mainly children and IT professionals. He quantifies risk, recalculating it on a regular basis to ensure that he is up to date with possible vulnerabilities and ready with mitigations.
+
+### 4\. Patch frequently but carefully
+
+Santa absolutely cannot afford for his systems to go down, particularly around his most busy period. He has established processes to ensure that the [concerns of security are balanced with the needs of the business][9].[5][10] He knows that sometimes business continuity must take priority, and on other occasions, the impact of a security breach would be so major that patches just _have_ to be applied. He tells people what he wants and listens to their views, taking them into account where he can. In other words, he embraces open management, delegating decisions where possible to the people who are best positioned to make the call, and only intervenes when asked for an executive decision or when exceptions arise. Santa is a _very_ enlightened manager.
+
+### 5\. Embrace diversity
+
+One of the useful consequences of running a global operation is that Santa values diversity. Old or young (at heart); male, female, or gender-neutral; neurotypical or neurodiverse; of any culture, sexuality, race, ability, creed, or nose colour, Santa takes into account his stakeholders and their views on what might go wrong. What a fantastic set of viewpoints Santa has available to him! And he's surprisingly hip to the opportunities for security practices that a wide and [diverse set of opinions and experiences][11] can bring[6][12] not to mention the multiple [positive impacts][13] on his organisation.
+
+### Summary
+
+Here's my advice: Be like Santa, and adopt at least some of his security practices. You'll have a much better opportunity of getting onto his good side, and that's going to go down well—not just with him, but also with your employer, who is just certain to give you a nice bonus, right? And if not, well, it's not too late to write that letter directly to Santa himself.
+
+* * *
+
+ 1. If you have a problem with this statement, then either you need to find another article, or you're reading this in the far future where all our climate problems have been solved. I hope.
+ 2. Or you dwell in one of those cultures where Santa visits quite early in December.
+ 3. A high-flying goose in the face can do terrible damage to a fast-moving reindeer, and if the sleigh were to crash, what then...?
+ 4. Not me!
+ 5. Santa doesn't refer to it as a "business," but he's happy for us to call it that, so we can model our own experience on his. He's nice like that.
+ 6. Though Santa would never use the phrase "hip to the opportunities." He's way too cool for that.
+
+
+
+Download the free All Things Open interview series eBook Jessica McKellar is an entrepreneur,...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/security-tips
+
+作者：[Mike Bursell][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/mikecamel
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/security_password_chaos_engineer_monster.png?itok=J31aRccu (Security monster)
+[2]: tmp.PgLkHLx1Uz#1
+[3]: tmp.PgLkHLx1Uz#2
+[4]: https://opensource.com/article/18/4/3-password-managers-linux-command-line
+[5]: tmp.PgLkHLx1Uz#3
+[6]: tmp.PgLkHLx1Uz#4
+[7]: https://opensource.com/article/18/1/being-open-about-data-privacy
+[8]: http://aliceevebob.com/2019/03/12/dont-talk-security-talk-risk/
+[9]: http://aliceevebob.com/2017/10/17/stop-reading-start-patching/
+[10]: tmp.PgLkHLx1Uz#5
+[11]: http://aliceevebob.com/2017/08/08/diversity-in-it-security-not-just-a-canine-issue/
+[12]: tmp.PgLkHLx1Uz#6
+[13]: https://opensource.com/article/19/11/diversity-and-inclusion-strategies
diff --git a/sources/tech/20191225 8 Commands to Check Memory Usage on Linux.md b/sources/tech/20191225 8 Commands to Check Memory Usage on Linux.md
new file mode 100644
index 0000000000..89108b5ded
--- /dev/null
+++ b/sources/tech/20191225 8 Commands to Check Memory Usage on Linux.md
@@ -0,0 +1,416 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (8 Commands to Check Memory Usage on Linux)
+[#]: via: (https://www.2daygeek.com/linux-commands-check-memory-usage/)
+[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
+
+8 Commands to Check Memory Usage on Linux
+======
+
+Linux is not like Windows and you will not get a GUI always, especially in a server environment.
+
+As a Linux administrator, it is important to know how to check your available and used resources, such as memory, CPU, disk space, etc.
+
+If there are any applications that use too much resources on the system to run your system at the optimum level you need to find and fix.
+
+If you want to **[find out the top 10 memory (RAM) consumption processes in Linux][1]**, go to the following article.
+
+In Linux, there are commands for everything, so use the corresponding commands.
+
+In this tutorial, we will show you eight powerful commands to check memory usage on a Linux system, including RAM and swap.
+
+**[Creating swap space on a Linux system][2]** is very important.
+
+The following commands can help you check memory usage in Linux in different ways.
+
+ * free Command
+ * /proc/meminfo File
+ * vmstat Command
+ * ps_mem Command
+ * smem Command
+ * top Command
+ * htop Command
+ * glances Command
+
+
+
+### 1) How to Check Memory Usage on Linux Using the free Command
+
+**[Free command][3]** is the most powerful command widely used by the Linux administrator. But it provides very little information compared to the “/proc/meminfo” file.
+
+Free command displays the total amount of free and used physical and swap memory on the system, as well as buffers and caches used by the kernel.
+
+These information is gathered from the “/proc/meminfo” file.
+
+```
+# free -m
+ total used free shared buff/cache available
+Mem: 15867 9199 1702 3315 4965 3039
+Swap: 17454 666 16788
+```
+
+ * **total:** Total installed memory
+ * **used:** Memory is currently in use by running processes (used= total – free – buff/cache)
+ * **free:** Unused memory (free= total – used – buff/cache)
+ * **shared:** Memory shared between two or more processes (multiple processes)
+ * **buffers:** Memory reserved by the kernel to hold a process queue request.
+ * **cache:** Size of the page cache that holds recently used files in RAM
+ * **buff/cache:** Buffers + Cache
+ * **available:** Estimation of how much memory is available for starting new applications, without swapping.
+
+
+
+### 2) How to Check Memory Usage on Linux Using the /proc/meminfo File
+
+The “/proc/meminfo” file is a virtual file that contains various real-time information about memory usage.
+
+It shows memory stats in kilobytes, most of which are somewhat difficult to understand.
+
+However it contains useful information about memory usage.
+
+```
+# cat /proc/meminfo
+
+MemTotal: 16248572 kB
+MemFree: 1764576 kB
+MemAvailable: 3136604 kB
+Buffers: 234132 kB
+Cached: 4731288 kB
+SwapCached: 28516 kB
+Active: 9004412 kB
+Inactive: 3552416 kB
+Active(anon): 8094128 kB
+Inactive(anon): 2896064 kB
+Active(file): 910284 kB
+Inactive(file): 656352 kB
+Unevictable: 80 kB
+Mlocked: 80 kB
+SwapTotal: 17873388 kB
+SwapFree: 17191328 kB
+Dirty: 252 kB
+Writeback: 0 kB
+AnonPages: 7566736 kB
+Mapped: 3692368 kB
+Shmem: 3398784 kB
+Slab: 278976 kB
+SReclaimable: 125480 kB
+SUnreclaim: 153496 kB
+KernelStack: 23936 kB
+PageTables: 73880 kB
+NFS_Unstable: 0 kB
+Bounce: 0 kB
+WritebackTmp: 0 kB
+CommitLimit: 25997672 kB
+Committed_AS: 24816804 kB
+VmallocTotal: 34359738367 kB
+VmallocUsed: 0 kB
+VmallocChunk: 0 kB
+Percpu: 3392 kB
+HardwareCorrupted: 0 kB
+AnonHugePages: 0 kB
+ShmemHugePages: 0 kB
+ShmemPmdMapped: 0 kB
+HugePages_Total: 0
+HugePages_Free: 0
+HugePages_Rsvd: 0
+HugePages_Surp: 0
+Hugepagesize: 2048 kB
+Hugetlb: 0 kB
+DirectMap4k: 1059088 kB
+DirectMap2M: 14493696 kB
+DirectMap1G: 2097152 kB
+```
+
+### 3) How to Check Memory Usage on Linux Using the vmstat Command
+
+The **[vmstat command][4]** is another useful tool for reporting virtual memory statistics.
+
+vmstat reports information about processes, memory, paging, block IO, traps, disks, and cpu functionality.
+
+vmstat does not require special permissions, and it can help identify system bottlenecks.
+
+```
+# vmstat
+
+procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
+ r b swpd free buff cache si so bi bo in cs us sy id wa st
+ 1 0 682060 1769324 234188 4853500 0 3 25 91 31 16 34 13 52 0 0
+```
+
+If you want to understand this in detail, read the field description below.
+
+**Procs**
+
+ * **r:** The number of runnable processes (running or waiting for run time).
+ * **b:** The number of processes in uninterruptible sleep.
+
+
+
+**Memory**
+
+ * **swpd:** the amount of virtual memory used.
+ * **free:** the amount of idle memory.
+ * **buff:** the amount of memory used as buffers.
+ * **cache:** the amount of memory used as cache.
+ * **inact:** the amount of inactive memory. (-a option)
+ * **active:** the amount of active memory. (-a option)
+
+
+
+**Swap**
+
+ * **si:** Amount of memory swapped in from disk (/s).
+ * **so:** Amount of memory swapped to disk (/s).
+
+
+
+**IO**
+
+ * **bi:** Blocks received from a block device (blocks/s).
+ * **bo:** Blocks sent to a block device (blocks/s).
+
+
+
+**System**
+
+ * **in:** The number of interrupts per second, including the clock.
+ * **cs:** The number of context switches per second.
+
+
+
+**CPU : These are percentages of total CPU time.**
+
+ * **us:** Time spent running non-kernel code. (user time, including nice time)
+ * **sy:** Time spent running kernel code. (system time)
+ * **id:** Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time.
+ * **wa:** Time spent waiting for IO. Prior to Linux 2.5.41, included in idle.
+ * **st:** Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown.
+
+
+
+Run the following command for detailed information.
+
+```
+# vmstat -s
+
+ 16248580 K total memory
+ 2210256 K used memory
+ 2311820 K active memory
+ 2153352 K inactive memory
+ 11368812 K free memory
+ 107584 K buffer memory
+ 2561928 K swap cache
+ 17873388 K total swap
+ 0 K used swap
+ 17873388 K free swap
+ 44309 non-nice user cpu ticks
+ 164 nice user cpu ticks
+ 14332 system cpu ticks
+ 382418 idle cpu ticks
+ 1248 IO-wait cpu ticks
+ 1407 IRQ cpu ticks
+ 2147 softirq cpu ticks
+ 0 stolen cpu ticks
+ 1022437 pages paged in
+ 260296 pages paged out
+ 0 pages swapped in
+ 0 pages swapped out
+ 1424838 interrupts
+ 4979524 CPU context switches
+ 1577163147 boot time
+ 3318 forks
+```
+
+### 4) How to Check Memory Usage on Linux Using the ps_mem Command
+
+**[ps_mem][5]** is a simple Python script that allows you to get core memory usage accurately for a program in Linux.
+
+This can determine how much RAM is used per program (not per process).
+
+It calculates the total amount of memory used per program, total = sum (private RAM for program processes) + sum (shared RAM for program processes).
+
+The shared RAM is problematic to calculate, and the tool automatically selects the most accurate method available for the running kernel.
+
+```
+# ps_mem
+
+ Private + Shared = RAM used Program
+180.0 KiB + 30.0 KiB = 210.0 KiB xf86-video-intel-backlight-helper (2)
+192.0 KiB + 66.0 KiB = 258.0 KiB cat (2)
+312.0 KiB + 38.5 KiB = 350.5 KiB lvmetad
+380.0 KiB + 25.5 KiB = 405.5 KiB crond
+392.0 KiB + 32.5 KiB = 424.5 KiB rtkit-daemon
+852.0 KiB + 117.0 KiB = 969.0 KiB gnome-session-ctl (2)
+928.0 KiB + 56.5 KiB = 984.5 KiB gvfs-mtp-volume-monitor
+ 1.0 MiB + 42.5 KiB = 1.0 MiB dconf-service
+ 1.0 MiB + 106.5 KiB = 1.1 MiB gvfs-goa-volume-monitor
+ 1.0 MiB + 180.5 KiB = 1.2 MiB gvfsd
+.
+.
+ 5.3 MiB + 3.0 MiB = 8.3 MiB evolution-addressbook-factory
+ 8.5 MiB + 1.2 MiB = 9.7 MiB gnome-session-binary (4)
+ 7.5 MiB + 3.1 MiB = 10.5 MiB polkitd
+ 7.4 MiB + 3.3 MiB = 10.7 MiB pulseaudio (2)
+ 7.0 MiB + 7.0 MiB = 14.0 MiB msm_notifier
+ 12.7 MiB + 2.3 MiB = 15.0 MiB evolution-source-registry
+ 13.3 MiB + 2.5 MiB = 15.8 MiB gnome-terminal-server
+ 15.8 MiB + 1.0 MiB = 16.8 MiB tracker-miner-fs
+ 18.7 MiB + 1.8 MiB = 20.5 MiB python3.7
+ 16.6 MiB + 4.0 MiB = 20.5 MiB evolution-calendar-factory
+ 22.3 MiB + 753.0 KiB = 23.0 MiB gsd-keyboard (2)
+ 22.4 MiB + 832.0 KiB = 23.2 MiB gsd-wacom (2)
+ 20.8 MiB + 2.5 MiB = 23.3 MiB blueman-tray
+ 22.0 MiB + 1.8 MiB = 23.8 MiB blueman-applet
+ 23.1 MiB + 934.0 KiB = 24.0 MiB gsd-xsettings (2)
+ 23.7 MiB + 1.2 MiB = 24.9 MiB gsd-media-keys (2)
+ 23.4 MiB + 1.6 MiB = 25.0 MiB gsd-color (2)
+ 23.9 MiB + 1.2 MiB = 25.1 MiB gsd-power (2)
+ 16.5 MiB + 8.9 MiB = 25.4 MiB evolution-alarm-notify
+ 27.2 MiB + 2.0 MiB = 29.2 MiB systemd-journald
+ 28.7 MiB + 2.8 MiB = 31.5 MiB c
+ 29.6 MiB + 2.2 MiB = 31.8 MiB chrome-gnome-sh (2)
+ 43.9 MiB + 6.8 MiB = 50.7 MiB WebExtensions
+ 46.7 MiB + 6.7 MiB = 53.5 MiB goa-daemon
+ 86.5 MiB + 55.2 MiB = 141.7 MiB Xorg (2)
+191.4 MiB + 24.1 MiB = 215.4 MiB notepadqq-bin
+306.7 MiB + 29.0 MiB = 335.7 MiB gnome-shell (2)
+601.6 MiB + 77.7 MiB = 679.2 MiB firefox
+ 1.0 GiB + 109.7 MiB = 1.1 GiB chrome (15)
+ 2.3 GiB + 123.1 MiB = 2.5 GiB Web Content (8)
+----------------------------------
+ 5.6 GiB
+==================================
+```
+
+### 5) How to Check Memory Usage on Linux Using the smem Command
+
+**[smem][6]** is a tool that can provide numerous reports of memory usage on Linux systems. Unlike existing tools, smem can report Proportional Set Size (PSS), Unique Set Size (USS) and Resident Set Size (RSS).
+
+Proportional Set Size (PSS): refers to the amount of memory used by libraries and applications in the virtual memory system.
+
+Unique Set Size (USS) : Unshared memory is reported as USS (Unique Set Size).
+
+Resident Set Size (RSS) : The standard measure of physical memory (it typically shared among multiple applications) usage known as resident set size (RSS) will significantly overestimate memory usage.
+
+```
+# smem -tk
+
+ PID User Command Swap USS PSS RSS
+3383 daygeek cat 0 92.0K 123.0K 1.7M
+3384 daygeek cat 0 100.0K 129.0K 1.7M
+1177 daygeek /usr/lib/gnome-session-ctl 0 436.0K 476.0K 4.6M
+1171 daygeek /usr/bin/dbus-daemon --conf 0 524.0K 629.0K 3.8M
+1238 daygeek /usr/lib/xdg-permission-sto 0 592.0K 681.0K 5.9M
+1350 daygeek /usr/lib/gsd-screensaver-pr 0 652.0K 701.0K 5.8M
+1135 daygeek /usr/lib/gdm-x-session --ru 0 648.0K 723.0K 6.0M
+.
+.
+1391 daygeek /usr/lib/evolution-data-ser 0 16.5M 25.2M 63.3M
+1416 daygeek caffeine-ng 0 28.7M 31.4M 66.2M
+4855 daygeek /opt/google/chrome/chrome - 0 38.3M 46.3M 120.6M
+2174 daygeek /usr/lib/firefox/firefox -c 0 44.0M 50.7M 120.3M
+1254 daygeek /usr/lib/goa-daemon 0 46.7M 53.3M 80.4M
+3416 daygeek /opt/google/chrome/chrome - 0 44.7M 54.2M 103.3M
+4782 daygeek /opt/google/chrome/chrome - 0 57.2M 65.8M 142.3M
+1137 daygeek /usr/lib/Xorg vt2 -displayf 0 77.2M 129.6M 192.3M
+3376 daygeek /opt/google/chrome/chrome 0 117.8M 131.0M 210.9M
+4448 daygeek /usr/lib/firefox/firefox -c 0 124.4M 133.8M 224.1M
+3558 daygeek /opt/google/chrome/chrome - 0 157.3M 165.7M 242.2M
+2310 daygeek /usr/lib/firefox/firefox -c 0 159.6M 169.4M 259.6M
+4331 daygeek /usr/lib/firefox/firefox -c 0 176.8M 186.2M 276.8M
+4034 daygeek /opt/google/chrome/chrome - 0 179.3M 187.9M 264.6M
+3911 daygeek /opt/google/chrome/chrome - 0 183.1M 191.8M 269.4M
+3861 daygeek /opt/google/chrome/chrome - 0 199.8M 208.2M 285.2M
+2746 daygeek /usr/bin/../lib/notepadqq/n 0 193.5M 217.5M 261.5M
+1194 daygeek /usr/bin/gnome-shell 0 203.7M 219.0M 285.1M
+2945 daygeek /usr/lib/firefox/firefox -c 0 294.5M 308.0M 410.2M
+2786 daygeek /usr/lib/firefox/firefox -c 0 341.2M 354.3M 459.1M
+4193 daygeek /usr/lib/firefox/firefox -c 0 417.4M 427.6M 519.3M
+2651 daygeek /usr/lib/firefox/firefox -c 0 417.0M 430.1M 535.6M
+2114 daygeek /usr/lib/firefox/firefox -c 0 430.6M 473.9M 610.9M
+2039 daygeek /usr/lib/firefox/firefox -- 0 601.3M 677.5M 840.6M
+-------------------------------------------------------------------------------
+ 90 1 0 4.8G 5.2G 8.0G
+```
+
+### 6) How to Check Memory Usage on Linux Using the top Command
+
+**[top command][7]** is one of the most frequently used commands by Linux administrators to understand and view the resource usage for a process on a Linux system.
+
+It displays the total memory of the system, current memory usage, free memory and total memory used by the buffers.
+
+In addition, it displays total swap memory, current swap usage, free swap memory, and total cached memory by the system.
+
+```
+# top -b | head -10
+
+top - 11:04:39 up 40 min, 1 user, load average: 1.59, 1.42, 1.28
+Tasks: 288 total, 2 running, 286 sleeping, 0 stopped, 0 zombie
+%Cpu(s): 13.3 us, 1.5 sy, 0.0 ni, 84.4 id, 0.0 wa, 0.3 hi, 0.5 si, 0.0 st
+KiB Mem : 16248572 total, 7755928 free, 4657736 used, 3834908 buff/cache
+KiB Swap: 17873388 total, 17873388 free, 0 used. 9179772 avail Mem
+
+ PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
+ 2114 daygeek 20 3182736 616624 328228 R 83.3 3.8 7:09.72 Web Content
+ 2039 daygeek 20 4437952 849616 261364 S 13.3 5.2 7:58.54 firefox
+ 1194 daygeek 20 4046856 291288 165460 S 4.2 1.8 1:57.68 gnome-shell
+ 4034 daygeek 20 808556 273244 88676 S 4.2 1.7 1:44.72 chrome
+ 2945 daygeek 20 3309832 416572 150112 S 3.3 2.6 4:04.60 Web Content
+ 1137 daygeek 20 564316 197292 183380 S 2.5 1.2 2:55.76 Xorg
+ 2651 daygeek 20 3098420 547260 275700 S 1.7 3.4 2:15.96 Web Content
+ 2786 daygeek 20 2957112 463912 240744 S 1.7 2.9 3:22.29 Web Content
+ 1 root 20 182756 10208 7760 S 0.8 0.1 0:04.51 systemd
+ 442 root -51 S 0.8 0:05.02 irq/141-iw+
+ 1426 daygeek 20 373660 48948 29820 S 0.8 0.3 0:03.55 python3
+ 2174 daygeek 20 2466680 122196 78604 S 0.8 0.8 0:17.75 WebExtensi+
+```
+
+### 7) How to Check Memory Usage on Linux Using the htop Command
+
+The **[htop command][8]** is an interactive process viewer for Linux/Unix systems. It is a text-mode application and requires the ncurses library, it was developed by Hisham.
+
+It is designed as an alternative to the top command.
+
+This is similar to the top command, but allows you to scroll vertically and horizontally to see all the processes running the system.
+
+htop comes with Visual Colors, which have added benefits and are very evident when it comes to tracking system performance.
+
+You are free to carry out any tasks related to processes, such as process killing and renicing without entering their PIDs.
+
+[![][9]][10]
+
+### 8) How to Check Memory Usage on Linux Using the glances Command
+
+**[Glances][11]** is a cross-platform system monitoring tool written in Python.
+
+You can see all information in one place such as CPU usage, Memory usage, running process, Network interface, Disk I/O, Raid, Sensors, Filesystem info, Docker, System info, Uptime, etc,.
+
+![][9]
+
+--------------------------------------------------------------------------------
+
+via: https://www.2daygeek.com/linux-commands-check-memory-usage/
+
+作者：[Magesh Maruthamuthu][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.2daygeek.com/author/magesh/
+[b]: https://github.com/lujun9972
+[1]: https://www.2daygeek.com/how-to-find-high-cpu-consumption-processes-in-linux/
+[2]: https://www.2daygeek.com/add-extend-increase-swap-space-memory-file-partition-linux/
+[3]: https://www.2daygeek.com/free-command-to-check-memory-usage-statistics-in-linux/
+[4]: https://www.2daygeek.com/linux-vmstat-command-examples-tool-report-virtual-memory-statistics/
+[5]: https://www.2daygeek.com/ps_mem-report-core-memory-usage-accurately-in-linux/
+[6]: https://www.2daygeek.com/smem-linux-memory-usage-statistics-reporting-tool/
+[7]: https://www.2daygeek.com/linux-top-command-linux-system-performance-monitoring-tool/
+[8]: https://www.2daygeek.com/linux-htop-command-linux-system-performance-resource-monitoring-tool/
+[9]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
+[10]: https://www.2daygeek.com/wp-content/uploads/2019/12/linux-commands-check-memory-usage-2.jpg
+[11]: https://www.2daygeek.com/linux-glances-advanced-real-time-linux-system-performance-monitoring-tool/
diff --git a/sources/tech/20191225 Khadas VIM3L- An Open Source HTPC Device.md b/sources/tech/20191225 Khadas VIM3L- An Open Source HTPC Device.md
new file mode 100644
index 0000000000..9d25522d26
--- /dev/null
+++ b/sources/tech/20191225 Khadas VIM3L- An Open Source HTPC Device.md
@@ -0,0 +1,149 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Khadas VIM3L: An Open Source HTPC Device)
+[#]: via: (https://itsfoss.com/vim3l/)
+[#]: author: (Community https://itsfoss.com/author/itsfoss/)
+
+Khadas VIM3L: An Open Source HTPC Device
+======
+
+If you’ve read our list of [Raspberry Pi alternatives][1], you might have come across VIM by Khadas.
+
+China-based [Khadas][2] is becoming increasingly popular for its single board computers (SCB). Apart from the generic do-it-yourself (DIY) VIM series, Khadas also has [Tone boards][3] that can be utilized for DJing and [Edge][4] boards for AI and other related projects.
+
+As discussed in [Raspberry Pi projects][5], one of the most popular use of a single board computer is to use it as a media center. You can turn your TV in more than just a smart TV (without being monitored) and play local music, videos, pictures and even games on your TV. You can also watch streaming services through these media center.
+
+You can always configure VIm (or any other SCB) as a media center. It’s a good DIY exercise but not everyone would like it.
+
+This is why Khadas has introduced [VIM3L][6] which is a ready to use media center device based on VIM 3. In this article, we’ll have a look at this device and see how to set it up.
+
+### VIM 3L specifications
+
+One of the strong point of Khadas is its emphasis on open source. All their source code, including [U-Boot][7], mainline Linux and Android is available on [their GitHub repository][8].
+
+VIM3L comes with [CoreELEC][9] operating system. CoreELEC is a custom Linux distribution that comes with software like [Kodi][10] and its add-ons to give you a complete HTPC (home theatre PC) experience.
+
+![][11]
+
+You are not restricted to CoreELEC though. You can get the barebon version of VIM 3L and use Android or install your a Linux distribution of your choice.
+
+ * Amlogic S905D3 SoC with quad-core Cortex-A55 CPU clocked at 1.9GHz
+ * 16GB eMMC
+ * 2GB RAM
+ * 2x WiFi antennas
+ * PCIe 2.0 and M.2 NVMe SSD support
+ * HDMI port
+ * Dolby Audio
+
+
+
+The HTPC version costs slightly more than the bare board but it consists of some additional hardware along with CoreELEC operating system:
+
+ * Transparent DIY case
+ * Metal DIY case
+ * Heatsink
+ * IR Remote
+
+
+
+![VIM3L HTPC Kit][12]
+
+VIM3L is capable of running 4K video at 75 fps. It also includes TrustZone based security for DRM video streaming. Both Android and CoreELEC are capable of [OTA updates][13].
+
+[VIM3L HTPC version costs $89.99][14] and the bare board (with Android) costs $69.99. It’s FOSS readers can _**get $6 off with itsfossfuns coupon code**_ that can be used at the checkout page of Khadas shop.
+
+[Khadas VIM3 Series][15]
+
+You may opt for the free shipping option but it will take 2-3 weeks for the device to reach you from China. You can pay $20 extra for an express DHL shipping. The shipping options are available at checkout. I think you might have to pay custom tax depending on your country’s rules so ordering one from Amazon would be better in such a case but you won’t get the It’s FOSS special discount on Amazon.
+
+Now that you are aware of the specifications, let me show you how to set it up and how was my experience with it.
+
+_The amazon links in this article are affiliate links. Please read our [affiliate policy][16]._
+
+### Setting up VIM3L and using it as home theatre PC
+
+Initially, when you start VIM3L, a window appears on the screen which consists of a series of questions and options. Everything you choose determines the initial state of its operation. In each case, however, you can modify your options from the settings menu. Better not to rush through the settings, since the multitude of options you have at startup seem to turn the VIM3L into a superpower device.
+
+![Setting up proxy network][17]
+
+The addition of the proxy connectivity in the internet settings is a welcome option. As a enthusiast of user privacy, I enabled it to connect through the [Tor network][18]. The choice is of course yours.
+
+![Peripheral devices][19]
+
+You can modify how many and which peripheral devices you have on that device. For example, in addition to the handheld control, you can mount a keyboard or even a console controller. Correct! A console controller that will allow you to play games.
+
+![Option to save logs][20]
+
+An important addition is the log storage option. With this, the users can consult the logs in case of an event of an error or malfunction. This could help in troubleshooting the issue.
+
+![Plenty of add-ons][21]
+
+On the left, a user can see options such as music, videos, radio, photos, games and many other options that we would like to take some time to cover.
+
+Add-ons further extends the capabilities of your HTPC. Here, you can find music libraries, documentaries, games, open-source software and more. The software includes various graphics, audio, and video editors, simulators etc.
+
+You have the freedom to choose whether you want to download them through 3rd party repositories, or from the environment of the accessory. Also, if you try to install software, you will most likely notice that along with the program, appropriate libraries and software are also installed. As you can see, this is not an accessory from scratch, but an accessory that is ready to cope with its users’ choices.
+
+VIM3L has different configuration profile consisting of a standard, intermediate, expert profile. As you climb into difficulty, your choices are multiplied, giving you total freedom.
+
+### Thoughts on VIM3L
+
+![][22]
+
+I liked VIM3L for what it offers. This is not to say that it is a perfect device.
+
+I found that some point, the controller is not fully accurate in signal transmission. As a result, after pressing a button twice, the signal is sent later and there is a quick change of screen. Maybe the controller I received was faulty.
+
+In conclusion, I would like to say that it’s not an expensive device and the feature it offers are good enough to provide you with entertainment, fun, productivity, and creativity. Most importantly, the software it offers are free and open source.
+
+If you like what you see here, you can either order it from [its own shop that ships from China][6] or get it from [Amazon][23].
+
+Preview | Product | Price |
+---|---|---|---
+![Khadas Amlogic S905D3 VIM3L HTPC Kit][24] ![Khadas Amlogic S905D3 VIM3L HTPC Kit][24] | [Khadas Amlogic S905D3 VIM3L HTPC Kit][25] | $89.99[][26] | [Buy on Amazon][27]
+
+Have you used VIM3L or any other pre-built media center device? Or do you prefer making your own HTPC? Do share your views.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/vim3l/
+
+作者：[Community][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/itsfoss/
+[b]: https://github.com/lujun9972
+[1]: https://itsfoss.com/raspberry-pi-alternatives/
+[2]: https://www.khadas.com/
+[3]: https://www.amazon.com/dp/B07K6GQNH3?tag=chmod7mediate-20&linkCode=ogi&th=1&psc=1 (Tone boards)
+[4]: https://www.khadas.com/edge
+[5]: https://itsfoss.com/raspberry-pi-projects/
+[6]: https://www.khadas.com/vim3l
+[7]: https://www.denx.de/wiki/U-Boot
+[8]: https://github.com/khadas
+[9]: https://coreelec.org/
+[10]: https://itsfoss.com/install-kodi-ubuntu/
+[11]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/VIM3L_OS_Freedom_graphic.jpg?ssl=1
+[12]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/VIM3L-Htpc-Kit.jpg?ssl=1
+[13]: https://source.android.com/devices/tech/ota
+[14]: https://www.amazon.com/dp/B081H66D7Q?tag=chmod7mediate-20&linkCode=ogi&th=1&psc=1 (VIM3L HTPC version costs $89.99)
+[15]: https://www.khadas.com/shop-vim3
+[16]: https://itsfoss.com/affiliate-policy/
+[17]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/khadas_vim3l_3.jpg?ssl=1
+[18]: https://itsfoss.com/tor-guide/
+[19]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/khadas_vim3l_2.jpg?ssl=1
+[20]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/khadas_vim3l_4.jpg?ssl=1
+[21]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/khadas_vim3l_1.jpg?ssl=1
+[22]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/VIM3L.jpg?ssl=1
+[23]: https://www.amazon.com/dp/B081H66D7Q?tag=chmod7mediate-20&linkCode=ogi&th=1&psc=1 (Amazon)
+[24]: https://i0.wp.com/m.media-amazon.com/images/I/41YC-mlA2PL._SL160_.jpg?ssl=1
+[25]: https://www.amazon.com/dp/B081H66D7Q?tag=chmod7mediate-20&linkCode=ogi&th=1&psc=1 (Khadas Amlogic S905D3 VIM3L HTPC Kit)
+[26]: https://www.amazon.com/gp/prime/?tag=chmod7mediate-20 (Amazon Prime)
+[27]: https://www.amazon.com/dp/B081H66D7Q?tag=chmod7mediate-20&linkCode=ogi&th=1&psc=1 (Buy on Amazon)
diff --git a/sources/tech/20191225 Making trade-offs when writing Python code.md b/sources/tech/20191225 Making trade-offs when writing Python code.md
new file mode 100644
index 0000000000..47da30cb93
--- /dev/null
+++ b/sources/tech/20191225 Making trade-offs when writing Python code.md
@@ -0,0 +1,61 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Making trade-offs when writing Python code)
+[#]: via: (https://opensource.com/article/19/12/zen-python-trade-offs)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+Making trade-offs when writing Python code
+======
+This is part of a special series about the Zen of Python focusing on the
+seventh, eighth, and ninth principles: readability, special cases, and
+practicality.
+![Brick wall between two people, a developer and an operations manager][1]
+
+Software development is a discipline rife with trade-offs. For every choice, there is an equally defensible but opposite choice. Make a method private? You're encouraging copy-paste. Make a method public? You're committing prematurely to an interface.
+
+Software developers make hard choices every minute. While all the principles in the [Zen of Python][2] cover trade-offs to some extent, the following principles take the hardest, coldest look at some trade-offs.
+
+### Readability counts.
+
+In some sense, this middle principle is indeed the center of the entire Zen of Python. The Zen is not about writing efficient programs. It is not even about writing robust programs, for the most part. It is about writing programs that _other people can read_.
+
+Reading code, by its nature, happens after the code has been added to the system. Often, it happens long after. Neglecting readability is the easiest choice since it does not hurt right now. Whatever the reason for adding new code—a painful bug or a highly requested feature—it does hurt. Right now.
+
+In the face of immense pressure to throw readability to the side and just "solve the problem," the Zen of Python reminds us: readability counts. Writing the code so it can be read is a form of compassion for yourself and others.
+
+### Special cases aren't special enough to break the rules.
+
+There is always an excuse. This bug is particularly painful; let's not worry about simplicity. This feature is particularly urgent; let's not worry about beauty. The domain rules covering this case are particularly hairy; let's not worry about nesting levels.
+
+Once we allow special pleading, the dam wall breaks, and there are no more principles; things devolve into a Mad Max dystopia with every programmer for themselves, trying to find the best excuses.
+
+Discipline requires commitment. It is only when things are hard, when there is a strong temptation, that a software developer is tested. There is always a valid excuse to break the rules, and that's why the rules must be kept the rules. Discipline is the art of saying no to exceptions. No amount of explanation can change that.
+
+### Although, practicality beats purity.
+
+> "If you think only of hitting, springing, striking, or touching the enemy, you will not be able actually to cut him."
+> — Miyamoto Musashi, _[The Book of Water][3]_
+
+Ultimately, software development is a practical discipline. Its goal is to solve real problems, faced by real people. Practicality beats purity: above all else, we must _solve the problem_. If we think only about readability, simplicity, or beauty, we will not be able to actually _solve the problem_.
+
+As Musashi suggested, the primary goal of every code change should be to _solve a problem_. The problem must be foremost in our minds. If we waver from it and think only of the Zen of Python, we have failed the Zen of Python. This is another one of those contradictions inherent in the Zen of Python.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/zen-python-trade-offs
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/devops_confusion_wall_questions.png?itok=zLS7K2JG (Brick wall between two people, a developer and an operations manager)
+[2]: https://www.python.org/dev/peps/pep-0020/
+[3]: https://en.wikipedia.org/wiki/The_Book_of_Five_Rings#The_Book_of_Water
diff --git a/sources/tech/20191226 -server- is hard to define.md b/sources/tech/20191226 -server- is hard to define.md
new file mode 100644
index 0000000000..e53338857b
--- /dev/null
+++ b/sources/tech/20191226 -server- is hard to define.md
@@ -0,0 +1,196 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: ("server" is hard to define)
+[#]: via: (https://jvns.ca/blog/2019/12/26/whats-a-server/)
+[#]: author: (Julia Evans https://jvns.ca/)
+
+"server" is hard to define
+======
+
+Somebody asked me recently what a server was, and I had a harder time explaining it than I expected! I thought I was going to be able to give some kind of simple pithy answer but it kind of got away from me. So here’s an short exploration of what the word “server” can mean:
+
+### a server responds to requests
+
+A server definitely responds to requests. A few examples:
+
+webserver:
+
+```
+Me: "please give me google.com"
+Server: "here is the HTML for that webpage"
+```
+
+bittorrent server:
+
+```
+Me: "I would like this chunk of the good wife season 2"
+Server: "here are some of the bytes from that .avi file!"
+```
+
+mail server:
+
+```
+Me: "can you send this email to [email protected]"
+Server: "I sent it!"
+```
+
+But what is a server actually specifically exactly?
+
+### a server is a program
+
+My first instinct is to say “a server is a program” because for example a “the wordpress server” is a PHP program, so let’s start with that.
+
+A server is usually a program that listens on a **port** (like 80). For example, if we’re talking about a Rails webserver, then the program is a Ruby program that’s listening on a port for HTTP requests.
+
+For example, we can start a Python server to serve files out of the current directory.
+
+```
+$ python3 -m http.server &
+Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ..
+```
+
+and send requests to it with `curl`:
+
+```
+$ curl localhost:8000/config.yaml
+baseurl: https://jvns.ca
+disablePathToLower: true
+languageCode: en-us
+title: Julia Evans
+author: Julia Evans
+...
+```
+
+### a server might be a virtual machine
+
+But often when I talk about “a server” at work, I’ll use it in a sentence like “I’m going to SSH to that server to see what’s going on with it”, or “wow, that server is swapping a lot, that’s bad!“.
+
+So in those cases clearly I don’t mean a program when I say “that server” (you can’t ssh to a program, though the ssh server that runs on the VM is itself a program!), I mean the AWS instance that the server program is running on. That AWS instance is a virtual machine, which looks like a computer in a lot of ways (it’s running an operating system!) but it isn’t a physical computer.
+
+### a server might be a container
+
+Similarly to how your server might be a virtual machine, it could also be a container running in a virtual machine. So “the server is running out of memory” could mean “the container is running out of memory and crashing” which really means “we set a cgroup memory limit on this container and the programs in the container with that cgroup exceeded the limit so the Linux kernel OOM killed them”.
+
+But containers make everything a lot more complicated so I think we should stop there for now.
+
+### a server is a computer
+
+But also when you **buy** a server from Dell or some other computer company, you’re not buying a virtual machine, you’re buying an actual physical machine.
+
+Usually these computers are in building datacenters. For example in this video you can see thousands of servers in a Google datacenter.
+
+The computers in this datacenter don’t look like the computers in my house! They’re short and wide because they’re designed to fit into these giant racks of servers. For example if you search Newegg for [1U server][1] you’ll find servers that are 1 “[rack unit][2]” high, and a rack unit is 1.75 inches. There are also 2U servers which are twice as high.
+
+Here’s a picture of a 1U server I found on Newegg:
+
+![][3]
+
+I’ve only seen a server rack once at the [Internet Archive][4] which is in what used to be a church in San Francisco, and it was really cool to realize – wow, when I use the Wayback Machine it’s using the actual computers in this room!
+
+### “the server” might be 1000 computers
+
+Next, let’s say we’re talking about how Gmail works. You might ask “hey, when I search my email to find my boarding pass, does that happen in the frontend or on the server?”.
+
+The answer is “it happens on the server”, but what’s “the server” here? There’s not just one computer or program or virtual machine that searches your Gmail, there are probably lots of computers and programs at Google that are reponsible for that and they’re probably distributed across many datacenters all over the world.
+
+And even if we’re just talking about doing 1 search, there could easily be 20 different computers in 3 different countries involved in just running that 1 search.
+
+So the words “the server” in “oh yeah, that happens on the server” mean something kind of complicated here – what you’re actually saying is something “well the browser makes a request, and that request does _something_, but I’m not really going to worry about what because the important thing is just that the browser made a request and got some kind of response back.”
+
+### what happens when I search my email for a boarding pass?
+
+When I search for “boarding” in my email, the Javascript running on the frontend puts together this request. It’s mostly indecipherable but it definitely contains the word “boarding”:
+
+```
+{
+ "1": {
+ "1": 79,
+ "2": 101,
+ "4": "boarding",
+ "5": {
+ "5": 0,
+ "12": "1577376926313",
+ "13": -18000000
+ },
+ "6": "itemlist-ViewType(79)-5",
+ "7": 1,
+ "8": 2000,
+ "10": 0,
+ "14": 1,
+ "16": {
+ "1": 1,
+ "2": 0,
+ "3": 0,
+ "7": 1
+ },
+ "19": 1
+ },
+ "3": {
+ "1": "0",
+ "2": 5,
+ "5": 1,
+ "6": 1,
+ "7": 1
+ }
+}
+```
+
+We get a response back which is large and complicated and definitely contains search results from my email about boarding passes. Here’s an excerpt:
+
+```
+"your electronic boarding pass. You could also be asked to display this \nmessage to airport security. * PLEASE NOTE: A printable",
+"the attached boarding pass to present at the airport. Manage your booking \nBooking Details Passenger: JULIA EVANS Booking",
+"Electronic boarding pass is not offered for your flight. Click the link \nbelow to access the PRINTABLE VERSION of your boarding",
+"Save time at the airport Save time at the airport Web version",
+"GET YOUR BOARDING PASS IN ADVANCE > You can now check in for your flight \nand you will receive a boarding pass > allowing",
+"Save time at the airport Save time at the airport Web version",
+"Booking Confirmation Booking Reference: xxxxxx Date of issue: xxxxxxxxxxxx \nSelect Seats eUpgrade",
+"your electronic boarding pass. You could also be asked to display this \nmessage to airport security. * PLEASE NOTE: A printable",
+"your electronic boarding pass. You could also be asked to display this \nmessage to airport security. * PLEASE NOTE: A printable",
+"Save time at the airport Save time at the airport Web version",
+"house was boarded up during the last round of bombings. I have no spatial \nimagination and cannot picture the house in three",
+"Booking Confirmation Booking Reference: xxxxxx Date of issue: xxxxxxxxxxxx \nSelect Seats eUpgrade"
+"required when boarding a flight to Canada. For more details, please visit \nCanada.ca/eTA . - Terms and Conditions of Sale",
+"Your KLM boarding pass(s) on XXXXXX To: [image: KLM SkyTeam] Boarding \ninformation Thank you for checking in! Attached you",
+"Boarding information Thank you for checking in! Attached you will find your \nboarding pass and/or other documents. Below",
+"jetBlue® Your upcoming trip to SEATTLE, WA on xxxxxxxxxxx Flight status \nBaggage info Airport info TAG",
+"your electronic boarding pass. You could also be asked to display this \nmessage to airport security. * PLEASE NOTE: A printable"
+```
+
+That request got sent to 172.217.13.197:443, which corresponds to some edge server near me. There were probably many other computers involved in searching my email than just the first one who got my request, but the nice thing about this is that we don’t need to care exactly what happened behind the scenes! The browser sent a request, and it got search results back, and it doesn’t need to know what servers.
+
+We can just say “it happens on the server” and not worry too much about the ambiguity of what exactly that means (until something weird goes wrong :)).
+
+### the meaning of “server” depends on the context
+
+So we’ve arrived somewhere a little bit interesting – at first when I thought about the question “what’s a server?” I really thought there was going to be a single simple answer! But it turns out that if you look at sentences where we use the word “server” it can actually refer to a lot of different things in a way that can be confusing:
+
+ * “Let me just ssh into the server and see what’s going on” => a virtual machine (or possibly a computer)
+ * “I sent a SIGTERM to the server and that fixed the problem” => a program
+ * “Let’s look at the server code” => a program
+ * “Let’s buy 20 of those 2U servers” => a computer
+ * “We need to add more server capacity” => a program and a virtual machine probably
+ * “That happens on the server” => possibly some complex distributed system
+
+
+
+--------------------------------------------------------------------------------
+
+via: https://jvns.ca/blog/2019/12/26/whats-a-server/
+
+作者：[Julia Evans][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://jvns.ca/
+[b]: https://github.com/lujun9972
+[1]: https://www.newegg.com/p/pl?d=1u+server
+[2]: https://en.wikipedia.org/wiki/Rack_unit
+[3]: https://c1.neweggimages.com/NeweggImage/ProductImage/11-152-136-02.jpg
+[4]: https://archive.org/
diff --git a/sources/tech/20191226 10 Linux command tutorials for beginners and experts.md b/sources/tech/20191226 10 Linux command tutorials for beginners and experts.md
new file mode 100644
index 0000000000..3172f26ea1
--- /dev/null
+++ b/sources/tech/20191226 10 Linux command tutorials for beginners and experts.md
@@ -0,0 +1,86 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (10 Linux command tutorials for beginners and experts)
+[#]: via: (https://opensource.com/article/19/12/linux-commands)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+10 Linux command tutorials for beginners and experts
+======
+Learn how to make Linux do what you need it to do in Opensource.com's
+top 10 articles about Linux commands from 2019.
+![Penguin driving a car with a yellow background][1]
+
+Using Linux _well_ means understanding what commands are available and what they're capable of doing for you. We have covered a lot of them on Opensource.com during 2019, and here are 10 favorites from the bunch.
+
+### Using the force at the Linux command line
+
+The Force has a light side and a dark side. Properly understanding that is crucial to true mastery. In his article [_Using the force at the Linux command line_][2], Alan Formy-Duval explains the **-f** option (also known as **\--force**) for several popular and sometimes dangerous commands.
+
+### Intro to the Linux useradd command
+
+Sharing accounts is a bad idea. Instead, give separate accounts to different people (and even different roles) with the quintessential **useradd** command. Part of his venerable series on basic Linux administration, Alan Formy-Duval provides an [_Intro to the Linux useradd command_][3], and, as usual, he explains it in _plain English_ so that both new and experienced admins can understand it.
+
+### Linux commands to display your hardware information
+
+What's _inside_ the box? Sometimes it's useful to inspect your hardware without using a screwdriver. In [_Linux commands to display your hardware information_][4], Howard Fosdick provides both popular and obscure commands to help you dig deep into the computer you're using, the computer you're testing at the store before buying, or the computer you're trying to repair.
+
+### How to encrypt files with gocryptfs on Linux
+
+Our files hold lots of private data, from social security numbers to personal letters to loved ones. In [_How to encrypt files with gocryptfs on Linux_][5], Brian "Bex" Exelbierd explains how to keep *private *what's meant to be private. As a bonus, he demonstrates encrypting files in a way that has little to no impact on your existing workflow. This isn't a complex PGP-style puzzle of key management and background key agents; this is quick, seamless, and secure file encryption.
+
+### How to use advanced rsync for large Linux backups
+
+In the New Year, many people will resolve to be more diligent about making backups. Alan Formy-Duval must have made that resolution years ago, because in [_How to use advanced rsync for large Linux backups_][6], he displays remarkable familiarity with the file synchronization command. You might not remember all the syntax right away, but the idea is to read and process the options, construct your backup command, and then automate it. That's the smart way to use **rsync**, and it's the _only_ way to do backups reliably.
+
+### Using more to view text files at the Linux command line
+
+In Scott Nesbitt's article [_Using more to view text files at the Linux command line_][7], the good old default pager **more** finally gets the spotlight. Many people install and use **less**, because it's more flexible than **more**. However, with more and more systems being implemented in the sparsest of containers, the luxury of fancy new tools like **less** or **most** sometimes just doesn't exist. Knowing and using **more** is simple, it's a common default, and it's the production system's debugging tool of last resort.
+
+### What you probably didn't know about sudo
+
+The **sudo** command is famous to a fault. People know the **sudo** term, and most of us believe we know what it does. And we're a little bit correct, but as Peter Czanik reveals in his article [_What you probably didn't know about sudo_][8], there's a lot more to the command than just "Simon says." Like that classic childhood game, the **sudo** command is powerful and also prone to silly mistakes—only with greater potential for horrible consequences. This is one game you do not want to lose!
+
+### How to program with Bash: Syntax and tools
+
+If you're a Linux, BSD, or Mac (and lately, Windows) user, you may have used the Bash shell interactively. It's a great shell for quick, one-off commands, which is why so many Linux users love to use it as their primary user interface. However, Bash is much more than just a command prompt. It's also a programming language, and if you're already using Bash commands, then the path to automation has never been more straightforward. Learn all about it in David Both's excellent [_How to program with Bash: Syntax and tools_][9].
+
+### Master the Linux ls command
+
+The **ls** command is one of those commands that merits a two-letter name; one-letter commands are an optimization for slow terminals where each letter causes a significant delay and also a nice bonus for lazy typists. Seth Kenlon explains how you can [_Master the Linux ls command_][10] and he does so with his usual clarity and pragmatism. Most significantly, in a system where "everything is a file," being able to list the files is crucial.
+
+### Getting started with the Linux cat command
+
+The **cat** command (short for con_cat_enate) is deceptively simple. Whether you use it to quickly see the contents of a file or to pipe the contents to another command, you may not be using **cat** to its full potential. Alan Formy-Duval's elucidating [_Getting started with the Linux cat command_][11] offers new ideas to take advantage of a command that lets you open a file without feeling like you've opened it. As a bonus, learn all about **zcat** so you can decompress files without all the trouble of decompression! It's a small and simple thing, but _this_ is what makes Linux great.
+
+### Continue the journey
+
+Don't let Opensource.com's 10 best articles about Linux commands of 2019 be the end of your journey. There's much more to discover about Linux and its versatile prompt, so stay tuned in 2020 for more insights. And, if there's a Linux command you want us to know about, please tell us about it in the comments, or share your knowledge with Opensource.com readers by [submitting an article][12] about your favorite Linux command.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/linux-commands
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/car-penguin-drive-linux-yellow.png?itok=twWGlYAc (Penguin driving a car with a yellow background)
+[2]: https://opensource.com/article/19/5/may-the-force-linux
+[3]: https://opensource.com/article/19/10/linux-useradd-command
+[4]: https://opensource.com/article/19/9/linux-commands-hardware-information
+[5]: https://opensource.com/article/19/8/how-encrypt-files-gocryptfs
+[6]: https://opensource.com/article/19/5/advanced-rsync
+[7]: https://opensource.com/article/19/1/more-text-files-linux
+[8]: https://opensource.com/article/19/10/know-about-sudo
+[9]: https://opensource.com/article/19/10/programming-bash-syntax-tools
+[10]: https://opensource.com/article/19/7/master-ls-command
+[11]: https://opensource.com/article/19/2/getting-started-cat-command
+[12]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191226 10 articles to become more data science savvy.md b/sources/tech/20191226 10 articles to become more data science savvy.md
new file mode 100644
index 0000000000..f334c7451a
--- /dev/null
+++ b/sources/tech/20191226 10 articles to become more data science savvy.md
@@ -0,0 +1,123 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (10 articles to become more data science savvy)
+[#]: via: (https://opensource.com/article/19/12/data-science-resources)
+[#]: author: (Lauren Maffeo https://opensource.com/users/lmaffeo)
+
+10 articles to become more data science savvy
+======
+Boost your data science game in 2020 with Opensource.com's top 10
+most-read articles on the topic from 2019.
+![Open data brain][1]
+
+When LinkedIn released its third annual [Emerging Jobs report][2], engineers everywhere said, "Amen." More than half the list consists of engineering roles, with new fields like robotics appearing for the first time.
+
+But data science had a strong showing as well. The role shows 37% annual growth, topping that aspect of the Emerging Jobs list for the third year in a row.
+
+Looking at the core skills a data scientist needs—including R, Python, and Apache Spark—it's easy to find overlaps with open source. So, we're not surprised that data science was one of the most popular topics at Opensource.com in 2019.
+
+We saw a need for knowledge about diverse data science topics. And our community of authors delivered answers.
+
+For your reading pleasure, we've listed the top 10 data science articles of 2019. We define "top" as the data science articles that were published in 2019 and earned the most page views, starting with the most popular.
+
+Whether you want to use Kubernetes for batch jobs or query 10 years' worth of GitHub data, these articles will boost your data science game in 2020.
+
+### Why data scientists love Kubernetes
+
+Kubernetes is having more than a moment. That's due in no small part to its versatility. You might already know that Kubernetes helps software developers and system operators deploy applications in Linux containers. But did you know how helpful it can be for data science as well?
+
+In [_Why data scientists love Kubernetes_][3], our most popular data science article in 2019, William Benton and Sophie Watson share how Kubernetes supports the data science workflow. From repeatable batch jobs to debugging ML models, this article shares several ways for data scientists to leverage Kubernetes.
+
+### How to use Spark SQL: A hands-on tutorial
+
+Wondering how to use a cloud service for big data analytics? [_How to use Spark SQL: A hands-on tutorial_][4] uses Spark DataFrames to show how to use relational databases at scale. DJ Sarkar uses a real-world dataset to walk readers through the process of using Spark SQL.
+
+Rich with screenshots and code, Sarkar's tutorial is the ideal sequel to [his first piece][5] on this subject. He shares several ways that you can use Spark to manage structured data obtained from flat files or databases.
+
+### 9 resources for data science projects
+
+The growth of data science in open source—from machine learning to neural networks—has left many engineers wanting to learn more. In [_9 resources for data science projects_][6], Dan Barker shares the books, tools, and online courses he thinks are a must for any engineer who wants to get started.
+
+Barker is especially keen on Cathy O'Neil's book [_Weapons of Math Destruction_][7], which shares how bias creeps into data and how you can stop it. He also shares a range of websites for newbies to explore.
+
+### Getting started with data science using Python
+
+Alongside the rise of data science techniques, Python has seen a meteoric rise. It's now one of the most popular programming languages. When used with libraries like pandas and Seaborn, Python is an ideal entry to data science.
+
+In [_Getting started with data science using Python_][8], a follow-up to his [intro to Python][9] article, Seth Kenlon shares how to create a Python virtual environment; install pandas and NumPy; create a sample dataset; and much more. This article is an especially good read if you want to learn more about data visualization.
+
+### How to analyze log data with Python and Apache Spark
+
+Like many articles in our top 10 list, [_How to analyze log data with Python and Apache Spark_][10] is a sequel to [an earlier article][11] on using Python and Apache Spark to wrangle data. Once you've learned how to put your data into a clean, structured format, DJ Sarkar offers this piece to help you analyze that data.
+
+Whether you want to see the top 10 error endpoints or content size statistics, Sarkar shows you how to analyze several types of log data in your [DataFrame][12]. The data that he uses isn't "big data" from a size or volume standpoint. But these techniques can scale for use with larger datasets.
+
+### How to wrangle log data with Python and Apache Spark
+
+[_How to wrangle log data with Python and Apache Spark_][11], DJ Sarkar's prequel to his piece on analyzing log data, also made our top 10 list. It's no surprise since most organizations use a range of systems and infrastructure that run constantly. Data logs are an ideal way to make sure that everything keeps working effectively.
+
+In this tutorial, Sarkar shows how to use Apache Spark on real-world production logs from NASA. He walks through the process of using Spark to do log analytics at scale on semi-structured log data. This ranges from setting up dependencies to data wrangling.
+
+### Querying 10 years of GitHub data with GHTorrent and Libraries.io
+
+Did you know that you can use Kibana or the Elasticsearch API to turn Amazon S3 object-storage data into a searchable Elasticsearch-type cluster? Likewise, did you know about the project that aims to build an offline version of all data available through GitHub APIs?
+
+In [_Querying 10 years of GitHub data with GHTorrent and Libraries.io_][13], Pete Cheslock explores how to access and query GHTorrent data. You can do it using several formats, including CSV and Google Big Query. Cheslock uses the latter to search indexed GHTorrent data to learn which software languages, licenses, and rates of growth are most popular for GitHub projects.
+
+### Predicting NFL play outcomes with Python and data science
+
+Want to increase your machine learning skills in Python? With the NFL playoff season upon us, it's a great time to read [_Predicting NFL play outcomes with Python and data science_][14], which shares some data science tips to predict plays.
+
+Christa Hayes shows how to spot weird values, predict downs and play types, make regression plots, and train models. Once you've read her article on [how to format data for training][15], this one is the ideal next step.
+
+### Analyzing the Stack Overflow Survey with Python and Pandas
+
+Stack Overflow's annual developer survey is a tech behemoth. Nearly 90,000 developers took this year's 20-minute survey and left a lot of data in their wake.
+
+To find certain results, Moshe Zadka used the pandas library to search the survey's [anonymized results][16]. If you want to filter Stack Overflow's dataset for certain details (like seeing how many developers use certain languages or contribute to open source projects), Moshe's [_Analyzing the Stack Overflow Survey with Python and Pandas_][17] tutorial shows you how.
+
+### 4 Python tools for getting started with astronomy
+
+For readers with their heads in the clouds, NumFOCUS republished some of its blog posts on Opensource.com this year. In [_4 Python tools for getting started with astronomy_][18], Dr. Gina Helfrich shares how you can get involved in astronomy.
+
+Intimidated? Don't be: Dr. Helfrich says Python packages are so advanced that building data-reduction scripts is much easier than ever before. If you want to play with astronomy imaging datasets, this piece will steer you in the right direction.
+
+### What do you want to know about data science?
+
+Data science is an exciting field with countless things to explore. If there's something you want to know about data science, please tell us about it in the comments so we can try to cover it in 2020. Or, if you are so inclined, please share your knowledge with Opensource.com readers by [submitting an article][19] about your favorite data science topic.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/data-science-resources
+
+作者：[Lauren Maffeo][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/lmaffeo
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc_520x292_opendata_0613mm.png?itok=UIjD_jhK (Open data brain)
+[2]: https://business.linkedin.com/content/dam/me/business/en-us/talent-solutions/emerging-jobs-report/Emerging_Jobs_Report_U.S._FINAL.pdf
+[3]: https://opensource.com/article/19/1/why-data-scientists-love-kubernetes
+[4]: https://opensource.com/article/19/3/apache-spark-and-dataframes-tutorial
+[5]: https://opensource.com/article/19/3/sql-scale-apache-spark-sql-and-dataframes
+[6]: https://opensource.com/article/19/2/learn-data-science-ai
+[7]: https://www.amazon.com/Weapons-Math-Destruction-Increases-Inequality/dp/0553418815
+[8]: https://opensource.com/article/19/9/get-started-data-science-python
+[9]: https://opensource.com/article/17/10/python-101
+[10]: https://opensource.com/article/19/5/visualize-log-data-apache-spark
+[11]: https://opensource.com/article/19/5/log-data-apache-spark
+[12]: https://pandas.pydata.org/pandas-docs/stable/getting_started/dsintro.html#dataframe
+[13]: https://opensource.com/article/19/5/chaossearch-github-ghtorrent
+[14]: https://opensource.com/article/19/10/predicting-nfl-plays-python
+[15]: https://opensource.com/article/19/10/formatting-nfl-data-python
+[16]: https://insights.stackoverflow.com/survey
+[17]: https://opensource.com/article/19/9/stack-overflow-survey-python-pandas
+[18]: https://opensource.com/article/19/10/python-astronomy-open-data
+[19]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191226 How the Zen of Python handles errors.md b/sources/tech/20191226 How the Zen of Python handles errors.md
new file mode 100644
index 0000000000..030c889db3
--- /dev/null
+++ b/sources/tech/20191226 How the Zen of Python handles errors.md
@@ -0,0 +1,56 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How the Zen of Python handles errors)
+[#]: via: (https://opensource.com/article/19/12/zen-python-errors)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+How the Zen of Python handles errors
+======
+This is part of a special series about the Zen of Python focusing on the
+10th and 11th principles: on the silence (or not) of errors.
+![a checklist for a team][1]
+
+Handling "exceptional conditions" is one of the most debated issues in programming. That could be because the stakes are high: mishandled error values can bring down even the largest systems. Since "exception conditions," by nature, are the least tested but occur with unpleasant frequency, correctly handling them can often distinguish a system that horror stories are told about to a system that "just works."
+
+From Java's **checked** exceptions through Erlang's fault isolation to Haskell's **Maybe**, different languages have remarkably different attitudes to error handling.
+
+The [Zen][2] offers Python's meditation on the topic.
+
+### Errors should never pass silently…
+
+Before the Zen of Python was a twinkle in Tim Peters' eye, before Wikipedia became informally known as "wiki," the first WikiWiki site, [C2][3], existed as a trove of programming guidelines. These are principles that mostly came out of a [Smalltalk][4] programming community. Smalltalk's ideas influenced many object-oriented languages, Python included.
+
+The C2 wiki defines the Samurai Principle: "return victorious, or not at all." In Pythonic terms, it encourages eschewing sentinel values, such as returning **None** or **-1** to indicate an inability to complete the task, in favor of raising exceptions. A **None** is silent: it looks like a value and can be put in a variable and passed around. Sometimes, it is even a _valid_ return value.
+
+The principle here is that if a function cannot accomplish its contract, it should "fail loudly": raise an exception. The raised exception will never look like a possible value. It will skip past the **returned_value = call_to_function(parameter)** line and go up the stack, potentially crashing the program.
+
+A crash is straightforward to debug: there is a stack trace indicating the problem as well as the call stack. The failure might mean that a necessary condition for the program was not met, and human intervention is needed. It might mean that the program's logic is faulty. In either case, the loud failure is better than a hidden, "missing" value, infecting the program's valid data with **None**, until it is used somewhere and an error message says "**None does not have method split**," which you probably already knew.
+
+### Unless explicitly silenced.
+
+Exceptions sometimes need to be explicitly caught. We might anticipate some of the lines in a file are misformatted and want to handle those in a special way, maybe by putting them in a "lines to be looked at by a human" file, instead of crashing the entire program.
+
+Python allows us to catch exceptions with **except**. This means errors can be _explicitly_ silenced. This explicitness means that the **except** line is visible in code reviews. It makes sense to question why this is the right place to silence, and potentially recover from, the exception. It makes sense to ask if we are catching too many exceptions or too few.
+
+Because this is all explicit, it is possible for someone to read the code and understand which exceptional conditions are recoverable.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/zen-python-errors
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/checklist_hands_team_collaboration.png?itok=u82QepPk (a checklist for a team)
+[2]: https://www.python.org/dev/peps/pep-0020/
+[3]: https://wiki.c2.com/
+[4]: https://en.wikipedia.org/wiki/Smalltalk
diff --git a/sources/tech/20191226 Top 10 Raspberry Pi articles of 2019.md b/sources/tech/20191226 Top 10 Raspberry Pi articles of 2019.md
new file mode 100644
index 0000000000..e4fae2c6ca
--- /dev/null
+++ b/sources/tech/20191226 Top 10 Raspberry Pi articles of 2019.md
@@ -0,0 +1,72 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Top 10 Raspberry Pi articles of 2019)
+[#]: via: (https://opensource.com/article/19/12/raspberry-pi-2019)
+[#]: author: (Joshua Allen Holm https://opensource.com/users/holmja)
+
+Top 10 Raspberry Pi articles of 2019
+======
+Take a look back at the year in Raspberry Pi and get excited for what's
+to come in 2020.
+![Raspberries with pi symbol overlay][1]
+
+Since its introduction, the Raspberry Pi has been one of the hottest topics on Opensource.com. This trend continued in 2019 with an impressive list of over 30 articles about various Raspberry Pi projects. The top 10 articles are covered below, but if you are a true Raspberry Pi aficionado, I encourage you to check out out our entire selection of [Raspberry Pi articles][2].
+
+ 1. _[Turn a Raspberry Pi 3B+ into a PriTunl VPN][3]_ by Stephen Bancroft demonstrates how to set up a PriTunl virtual private networking (VPN) on a Raspberry Pi 3B+. There are several sticky points about the process that Bancroft helpfully and clearly explains. Following his instructions, you can easily turn a Raspberry Pi into a VPN server.
+
+ 2. In _[Let’s get physical: How to use GPIO pins on the Raspberry Pi][4]_, Anderson Silva provides a brief introduction to using the GPIO pins on a Raspberry Pi. The article is full of links to other resources, including some of Silva’s other pieces, for those who want to dig deeper into the topic.
+
+ 3. Sam Bocetta’s article _[How to use your Raspberry Pi as a VPN server][5]_, demonstrates how to install and configure PiVPN on a Raspberry Pi to create a VPN server. The article covers every aspect of the installation and configuration process, so if the reader has followed all the instructions provided, they will end up with their own Raspberry Pi-powered VPN.
+
+ 4. _[Program the real world using Rust on Raspberry Pi][6]_ by Rahul Thakoor explores how to use the Rust programming language on the Raspberry Pi. By adding **rust_gpiozero** to a Rust project, it is possible to write code in Rust that can interact with buttons, servos, and other hardware connected to a Raspberry Pi. This article shows you how to get started.
+
+ 5. Ben Nuttall, Raspberry Pi community manager, proclaims _[Raspberry Pi 4 is here!][7]_ in this article covering the release of the Raspberry Pi 4. The Raspberry Pi 4 features many improvements over previous Raspberry Pi models, and Nuttall walks through them in detail. From the new hardware features to the software updates in the updated release of Raspbian, this article brings you up to speed on what the Raspberry Pi 4 brings to the Raspberry Pi ecosystem.
+
+ 6. _[How to build a WiFi picture frame with a Raspberry Pi][8]_ by Manuel Dewald shows you how to create a WiFi-connected digital picture frame using a Raspberry Pi 3. This step-by-step tutorial provides all the instructions needed to configure the software, but if you want to make a fancy case for your digital picture frame, that part is up to you.
+
+ 7. Anderson Silva’s _[How to boot up a new Raspberry Pi][9]_ explains what you need to do to boot an operating system on a Raspberry Pi. This article primarily provides an overview of NOOBS (New Out Of Box Software) and contains links to the official Raspberry Pi website for the most up-to-date installation instructions.
+
+ 8. _[How to build a mobile particulate matter sensor with a Raspberry Pi][10]_ by Stephan Tetzel illustrates how to build a sensor that can monitor your air quality using a Raspberry Pi, a small LCD display, and an inexpensive sensor. The particulate matter sensor you create can be used anywhere when paired with a power bank.
+
+ 9. _[3 popular programming languages you can learn with Raspberry Pi][11]_ by Anderson Silva looks at programming Python, Java, and JavaScript on the Raspberry Pi. The Thonny IDE for Python and the BlueJ IDE for Java are briefly covered. The article also encourages users who are interested in other programming languages with the assurance that "there’s a high likelihood that you can use your Raspberry Pi to compile or interpret any language of choice, including C, C++, PHP, and Ruby."
+
+ 10. Take a trip down memory lane by _[Resurrecting the Amiga on the Raspberry Pi][12]_ with this guide by Sarah Thornton. Using the instructions provided, you can experience the Amiga again on a Raspberry Pi or several other devices. Thornton even provides a helpful set of links for those interested in learning more about the history of the Amiga.
+
+
+
+
+I hope these articles encourage you to explore the possibilities of the Raspberry Pi. Maybe they have even inspired you to [share your own Raspberry Pi story][13] with us? Your story could end up on this list next year!
+
+In this month's Raspberry Pi column, Ben Nuttall introduces readers to five projects that you might...
+
+Owning a little cloud has a lot of benefits and can save you over $100 per month. In this step-by-...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/raspberry-pi-2019
+
+作者：[Joshua Allen Holm][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/holmja
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/life-raspberrypi_0.png?itok=Kczz87J2 (Raspberries with pi symbol overlay)
+[2]: https://opensource.com/tags/raspberry-pi
+[3]: https://opensource.com/article/19/1/pritunl-vpn-raspberry-pi
+[4]: https://opensource.com/article/19/3/gpio-pins-raspberry-pi
+[5]: https://opensource.com/article/19/6/raspberry-pi-vpn-server
+[6]: https://opensource.com/article/19/3/physical-computing-rust-raspberry-pi
+[7]: https://opensource.com/article/19/6/raspberry-pi-4
+[8]: https://opensource.com/article/19/2/wifi-picture-frame-raspberry-pi
+[9]: https://opensource.com/article/19/3/how-boot-new-raspberry-pi
+[10]: https://opensource.com/article/19/3/mobile-particulate-matter-sensor
+[11]: https://opensource.com/article/19/3/programming-languages-raspberry-pi
+[12]: https://opensource.com/article/19/3/amiga-raspberry-pi
+[13]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191227 Explained- Why Your Distribution Still Using an ‘Outdated- Linux Kernel.md b/sources/tech/20191227 Explained- Why Your Distribution Still Using an ‘Outdated- Linux Kernel.md
new file mode 100644
index 0000000000..6152697eb3
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+++ b/sources/tech/20191227 Explained- Why Your Distribution Still Using an ‘Outdated- Linux Kernel.md
@@ -0,0 +1,120 @@
+[#]: collector: (lujun9972)
+[#]: translator: (chen-ni)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Explained! Why Your Distribution Still Using an ‘Outdated’ Linux Kernel?)
+[#]: via: (https://itsfoss.com/why-distros-use-old-kernel/)
+[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
+
+Explained! Why Your Distribution Still Using an ‘Outdated’ Linux Kernel?
+======
+
+[Check your Linux kernel version][1]. Chances are that you’ll find that the kernel version your system is using has already reached end of life (EOL) as listed on Linux Kernel website.
+
+End of life means a software won’t get bug fixes and support anymore.
+
+That poses some valid questions. Why is my Linux distribution using a kernel that has reached end of life? Is this not a security risk? Is my system safe?
+
+Let me explain all these questions in this article.
+
+Summary
+
+The upstream kernel support and the your distribution’s kernel support are two different things.
+
+For example, Linux kernel 4.15 might have reached end of life (as per the official Linux kernel website) but Ubuntu 18.04 LTS release will use it and maintain it till April 2023 by backporting security patches and bug fixes.
+
+### Checking Linux kernel version and finding its end of life status
+
+Let’s first check the Linux kernel version on your system:
+
+```
+uname -r
+```
+
+I am using Ubuntu 18.04 here and it shows the Linux kernel version like this:
+
+```
+[email protected]:~$ uname -r
+5.0.0-37-generic
+```
+
+Now, you may go to the official Linux kernel website and see what Linux kernels are still being supported. It’s displayed on the homepage itself.
+
+[Linux Kernel Official Website][2]
+
+You should see a status like this:
+
+![Linux Kernel Status][3]
+
+If you don’t see a kernel version listed on the homepage of kernel website, it means that specific version has reached end of life.
+
+As you can see, kernel 5.0 is not listed here. It indicates that this kernel version is not being supported anymore. Actually, it [reached end of life in June 2019][4].
+
+The life cycle of a Linux kernel doesn’t follow a set pattern, unfortunately. It’s NOT like a regular kernel stable release will be supported for X months and a long term support(LTS) kernel will be supported for Y years.
+
+Based on the demand and requirements, there could be several LTS kernel versions with different EOL. You can find them along with their projected EOL on [this page][5].
+
+Now comes the big question. Why is Ubuntu providing kernel 5.0 if the Linux kernel website shows that it has reached its end of life?
+
+### Your distribution uses an EOL Linux kernel but that’s Okay!
+
+![][6]
+
+Have you ever wondered why Ubuntu/Debian/Fedora etc are called Linux distributions? It’s because they ‘distribute’ the Linux kernel.
+
+They have their own modification of the Linux kernel, they add the GUI elements (desktop environment, display server etc) and software and they make it available to their users.
+
+In the typical workflow, a Linux distribution will choose a kernel to provide to its users. And then it will hold on to this kernel for months or years even after the kernel has reached end of life.
+
+How is it safe then? It’s because the _**distribution maintains the kernel by backporting all the important fixes to its kernel**_.
+
+In other words, your Linux distribution makes sure that your Linux kernel is patched well and has all the bug fixes and important new features backported to it. There will be thousands of changes on top of the ‘old outdated Linux kernel’.
+
+When the Linux kernel website says that a certain kernel version has reached EOL, it means that the core Linux kernel maintainers are not going to update/patch that kernel version anymore.
+
+But at the same time, the developers at Debian/Ubuntu or other distributions work to keep the same old version alive by bringing the relevant changes from the newer kernel versions (being maintained by the core kernel team) to your distribution’s old kernel.
+
+Bottom line is that even if it seems like your distribution is using an outdated Linux kernel, it is actually being well maintained and not really outdated.
+
+### Should you use the latest stable kernel version?
+
+![][7]
+
+A new stable Linux kernel version is released every 2-3 months. And this makes many users wonder who they can get their hands on that new shiny thing.
+
+To be frank, you should not do that unless you have a pretty good reason for it. Your distribution doesn’t provide it to you. You cannot just use ‘_sudo apt give-me-the-latest-stable-kernel_‘.
+
+Now, manually [installing the mainline Linux kernel version][8] could be a challenge in itself. Even if you manage to install it, it is now up to you to make sure that this kernel is updated every time there is a bug fix. And when this new kernel reaches end of life, it becomes your responsibility to upgrade to the newer kernel version. It won’t be handled with apt upgrade like regular [Ubuntu updates][9].
+
+You should also keep in mind that your distribution also has drivers and patches which you may not be able to use if you switch to the mainline kernel.
+
+As [Greg Kroah-Hartman][10] puts it, “_**the best kernel you can use is one that someone else supports**_“. And who can be better at this job then your Linux distribution!
+
+I hope you have a better understanding on this topic and you won’t panic the next time you find out that the kernel version your system is using has reached end of life.
+
+I welcome your questions and suggestions. Please feel free to use the comment section.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/why-distros-use-old-kernel/
+
+作者：[Abhishek Prakash][a]
+选题：[lujun9972][b]
+译者：[chen-ni](https://github.com/chen-ni)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/abhishek/
+[b]: https://github.com/lujun9972
+[1]: https://itsfoss.com/find-which-kernel-version-is-running-in-ubuntu/
+[2]: https://www.kernel.org/
+[3]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/linux-kernel-status.jpg?ssl=1
+[4]: http://lkml.iu.edu/hypermail/linux/kernel/1906.0/02354.html
+[5]: https://www.kernel.org/category/releases.html
+[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/Keep_Calm_and_Trust_Your_Distribution.png?ssl=1
+[7]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/using_latest_kernel.png?ssl=1
+[8]: https://wiki.ubuntu.com/Kernel/MainlineBuilds
+[9]: https://itsfoss.com/update-ubuntu/
+[10]: https://en.wikipedia.org/wiki/Greg_Kroah-Hartman
diff --git a/sources/tech/20191227 The importance of consistency in your Python code.md b/sources/tech/20191227 The importance of consistency in your Python code.md
new file mode 100644
index 0000000000..812a4df058
--- /dev/null
+++ b/sources/tech/20191227 The importance of consistency in your Python code.md
@@ -0,0 +1,71 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (The importance of consistency in your Python code)
+[#]: via: (https://opensource.com/article/19/12/zen-python-consistency)
+[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
+
+The importance of consistency in your Python code
+======
+This is part of a special series about the Zen of Python focusing on the
+12th, 13th, and 14th principles: the roles of ambiguity and obviousness.
+![Two animated computers waving one missing an arm][1]
+
+The principle of least surprise is [a guideline][2] when designing user interfaces. It says that when the user performs an action, the program should do whatever would surprise the user the least. This is for the same reason kids love reading the same book over and over again: there is nothing more comforting to people than the ability to predict and have those predictions come true.
+
+A critical insight in the development of the [ABC language][3], Python's inspiration, was that programming languages are user interfaces and need to be designed with the same tools that UI designers use. Thankfully, since then, more languages have adopted the concepts of affordance and ergonomics from UI design, even if they apply them less strictly.
+
+This brings us to the next three principles in the [Zen of Python][4].
+
+### In the face of ambiguity, refuse the temptation to guess.
+
+What should the result of **1 + "1"** be? Both **"11"** and **2** would be valid guesses. This expression is _ambiguous_: there is no single thing it can do that would not be a surprise to at least some people.
+
+Some languages choose to guess. In JavaScript, the result is **"11"**. In Perl, the result is **2**. In C, naturally, the result is the empty string. In the face of ambiguity, JavaScript, Perl, and C all guess.
+
+In Python, this raises a **TypeError**: an error that is not silent. It is atypical to catch **TypeError**: it will usually terminate the program or at least the current task (for example, in most web frameworks, it will terminate the handling of the current request).
+
+Python refuses to guess what **1 + "1"** means. The programmer is forced to write code with clear intention: either **1 + int("1")**, which would be **2**; or **str(1) + "1"**, which would be **"11"**; or **"1"[1:]**, which would be an empty string. By refusing to guess, Python makes programs more predictable.
+
+### There should be one—and preferably only one—obvious way to do it.
+
+Prediction also goes the other way. Given a task, can you predict the code that will be written to achieve it? It is impossible, of course, to predict perfectly. Programming, after all, is a creative task.
+
+However, there is no reason to intentionally provide multiple, redundant ways to achieve the same thing. There is a sense in which some solutions are "better" or "more Pythonic."
+
+Part of the appreciation for the Pythonic aesthetic is that it is OK to have healthy debates about which solution is better. It is even OK to disagree and keep programming. It is even OK to agree to disagree for the sake of harmony. But beneath it all, there has to be a feeling that, eventually, the right solution will come to light. There must be the hope that eventually we can live in true harmony by agreeing on the best way to achieve a goal.
+
+### Although that way may not be obvious at first (unless you're Dutch).
+
+This is an important caveat: It is often _not_ obvious, at first, what is the best way to achieve a task. Ideas are evolving. _Python_ is evolving. The best way to read a file block-by-block is, probably, to wait until Python 3.8 and use the [walrus operator][5].
+
+This common task, reading a file block-by-block, did not have a "single best way to do it" for almost _30 years_ of Python's existence.
+
+When I started using Python in 1998 with Python 1.5.2, there was no single best way to read a file line-by-line. For many years, the best way to know if a dictionary had a key was to use **.haskey**, until the **in** operator became the best way.
+
+It is only by appreciating that sometimes, finding the one (and only one) way of achieving a goal can take 30 years of trying out alternatives that Python can keep aiming to find those ways. This view of history, where 30 years is an acceptable time for something to take, often feels foreign to people in the United States, when the country has existed for just over 200 years.
+
+The Dutch, whether it's Python creator [Guido van Rossum][6] or famous computer scientist [Edsger W. Dijkstra][7], have a different worldview according to this part of the Zen of Python. A certain European appreciation for time is essential to appreciate it.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/zen-python-consistency
+
+作者：[Moshe Zadka][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/moshez
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/rh_003499_01_other11x_cc.png?itok=I_kCDYj0 (Two animated computers waving one missing an arm)
+[2]: https://www.uxpassion.com/blog/the-principle-of-least-surprise/
+[3]: https://en.wikipedia.org/wiki/ABC_(programming_language)
+[4]: https://www.python.org/dev/peps/pep-0020/
+[5]: https://www.python.org/dev/peps/pep-0572/#abstract
+[6]: https://en.wikipedia.org/wiki/Guido_van_Rossum
+[7]: http://en.wikipedia.org/wiki/Edsger_W._Dijkstra
diff --git a/sources/tech/20191227 Top CI-CD resources to set you up for success.md b/sources/tech/20191227 Top CI-CD resources to set you up for success.md
new file mode 100644
index 0000000000..77d2391a5d
--- /dev/null
+++ b/sources/tech/20191227 Top CI-CD resources to set you up for success.md
@@ -0,0 +1,57 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Top CI/CD resources to set you up for success)
+[#]: via: (https://opensource.com/article/19/12/cicd-resources)
+[#]: author: (Jessica Cherry https://opensource.com/users/jrepka)
+
+Top CI/CD resources to set you up for success
+======
+Continuous integration and continuous deployment were key topics in 2019
+as organizations look to achieve seamless, flexible, and scalable
+deployments.
+![Plumbing tubes in many directions][1]
+
+This has been a fantastic year for continuous integration/continuous deployment (CI/CD) and the world of DevOps. Opensource.com authors shared how they're moving toward agile and scrum as they focus on seamless, flexible, and scalable deployments. Here are some of the big themes in the CI/CD articles we published this year.
+
+### Learning and improving your CI/CD skills
+
+Some of our favorite articles focus on hands-on CI/CD experience and cover a lot of ground as they do. The place to start is always with [Jenkins][2] pipelines, and Bryant Son's [_Building CI/CD pipelines with Jenkins_][3] will give you enough experience to get started building your first pipelines. Daniel Oh's [_Automate user acceptance testing with your DevOps pipeline_][4] provides great information on acceptance testing, including various CI/CD applications you can use for testing in its own right. And my article on [_Security scanning your DevOps pipeline_][5] is a very short, to the point tutorial on how to set up security in a pipeline using the Jenkins platform.
+
+### Delivery workflow
+
+While learning how to use and improve your skills with CI/CD, the workflow matters, especially when it comes to pipelines, as Jithin Emmanuel shares in [_Screwdriver: A scalable build platform for continuous delivery_][6]. Emily Burns explains having the flexibility to build exactly what you need with your CI/CD workflow in [_Why Spinnaker matters to CI/CD_][7]. And Willy-Peter Schaub extols the idea of creating a unified pipeline for everything to build consistently in [_One CI/CD pipeline per product to rule them all_][8]. These articles will give you a good sense of what happens after you onboard team members to the workflow process.
+
+### How CI/CD affects organizations
+
+2019 was also the year of recognizing CI/CD's business impact and how it affects day-to-day operations. Agnieszka Gancarczyk shares the results of Red Hat's [_Small Scale Scrum vs. Large Scale Scrum_][9] survey, including respondents' differing opinions on scrums, the agile movement, and the impact on teams. Will Kelly covers [_How continuous deployment impacts the entire organization_][10], including the importance of open communication, and Daniel Oh emphasizes the importance of metrics and observability in [_3 types of metric dashboards for DevOps teams_][11]. Last, but far from least, Ann Marie Fred's great article [_Don't test in production? Test in production!_][12] details why it's important for you to test in production—before your customers do.
+
+We are thankful to the many contributing authors who shared their insights with Opensource.com readers in 2019, and I look forward to learning more from them about the evolution of CI/CD in 2020.
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/cicd-resources
+
+作者：[Jessica Cherry][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/jrepka
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/plumbing_pipes_tutorial_how_behind_scenes.png?itok=F2Z8OJV1 (Plumbing tubes in many directions)
+[2]: https://jenkins.io/
+[3]: https://opensource.com/article/19/9/intro-building-cicd-pipelines-jenkins
+[4]: https://opensource.com/article/19/4/devops-pipeline-acceptance-testing
+[5]: https://opensource.com/article/19/7/security-scanning-your-devops-pipeline
+[6]: https://opensource.com/article/19/3/screwdriver-cicd
+[7]: https://opensource.com/article/19/8/why-spinnaker-matters-cicd
+[8]: https://opensource.com/article/19/7/cicd-pipeline-rule-them-all
+[9]: https://opensource.com/article/19/3/small-scale-scrum-vs-large-scale-scrum
+[10]: https://opensource.com/article/19/7/organizational-impact-continuous-deployment
+[11]: https://opensource.com/article/19/7/dashboards-devops-teams
+[12]: https://opensource.com/article/19/5/dont-test-production
diff --git a/sources/tech/20191228 Most-read open source news stories of 2019.md b/sources/tech/20191228 Most-read open source news stories of 2019.md
new file mode 100644
index 0000000000..6c5955bc84
--- /dev/null
+++ b/sources/tech/20191228 Most-read open source news stories of 2019.md
@@ -0,0 +1,90 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Most-read open source news stories of 2019)
+[#]: via: (https://opensource.com/article/19/12/open-source-news)
+[#]: author: (Scott Nesbitt https://opensource.com/users/scottnesbitt)
+
+Most-read open source news stories of 2019
+======
+Here are some of the big news items from the year and a look at the
+future of open source.
+![Radio wave.][1]
+
+A great deal happened in the world of open source in 2019. Once upon a time, you would have been hard-pressed to find news about Linux, free software, and open source software outside of a small handful of specialist publications. Today, though, news about open source is everywhere; the online edition of Forbes even has its own [Linux columnist][2].
+
+We regularly round up many of the most interesting and topical news articles in [fortnightly articles][3]. Of those, we’ve compiled the top 10 most read (by you, our readers) stories we curated during 2019.
+
+### Google's trusted hardware project
+
+Many of us take the security of our software seriously but, at the same time, take the security of our hardware for granted. How do we know if the hardware we’re using is secure and trusted? To help ensure that it is, Google [announced OpenTitan][4], a secure, open source chip design project. The project builds upon a chip that Google developed called Titan, and the search giant has recruited several hardware manufacturers to join this initiative.
+
+### Database makers embrace open source licenses
+
+Over the last 18 months or so, several open source database firms moved to less open licenses for the software they develop in an attempt to stay competitive in a tough market. Cloudera and YugaByte, however, went in the opposite direction in 2019. Cloudera put the proprietary portions of its products under the umbrella of the [AGPL and Apache 2.0 licenses][5], while YugaByte [announced it was adopting][6] the Apache 2.0 license for its wares.
+
+### GNOME and KDE agree to work together
+
+It’s always great when two rivals put aside their differences to work for a greater good; especially when that greater good is the further advancement of the Linux desktop. That’s what happened when the GNOME Foundation and KDE [announced they were going to work together][7]. The goal is to bring the GNOME and KDE communities together "to build an application ecosystem that transcends individual distros and broadens the market for everyone."
+
+### System76 announces Linux laptops with Coreboot firmware
+
+While there are several small companies selling Linux-powered computers, not all components of those computers are open source. That’s especially true for their firmware. Computer maker System76 is trying to change that. The company announced that it will [ship two of its most popular laptops][8] with the lightweight Coreboot open source firmware. According to Forbes Online, by adopting Coreboot (which helps computers start faster) System76 is taking another step in "the company’s steady march toward offering open source software and hardware."
+
+### Open source platform spans the globe to help local communities
+
+Open source knows no borders. Proof of that is at the St. Francis Neighborhood Center in West Baltimore, which [adopted the Lutèce platform][9] to help deliver its programs and services. While Lutèce was developed in France and runs services in French cities like Paris, Lyon, and Marseille, the implementation in West Baltimore is the first time the platform has been used outside of its country of origin.
+
+### Australian government uses open source to build notification platform
+
+When Australia’s Digital Transformation Agency (DTA) need to quickly deploy an email and text message notification system, it turned to software developed by the Government Digital Service in the UK. The result was a platform called Notify. Using existing software enabled the DTA to [get the platform up and running][10] in eight weeks. Notify is now being used by over 100 government departments across the country.
+
+### Dutch city to further embrace open source
+
+Like many cities in Europe, Nijmegen in the eastern part of the Netherlands has long been an advocate of using open source in government. Unfortunately, the city’s procurement processes still favored proprietary solutions. That’s starting to change, thanks to a [resolution passed in 2019][11] which requires the city to "deploy both the mandatory and the recommended open standards listed by the Dutch Standardisation Forum." The municipal government hopes that the resolution will spur wider use of open source software to avoid vendor lock-in.
+
+### Acquia buys Mautic
+
+Acquia, the company behind the popular open source content management system Drupal, took a big step in its ambition to create the first "open digital experience platform" by acquiring open source marketing automation firm Mautic. The idea behind the acquisition is to give companies that use Acquia’s offerings "the freedom they need to own their digital destiny without the constraint of vendor lock-in."
+
+### Mozilla Labs makes a return
+
+A few years ago, Mozilla had seemed to abandoned Mozilla Labs. Labs, you might remember, was the home of various beta features for Firefox that users could test drive. In early 2019, Mozilla [brought Labs back][12] with more experimental goodness. The new edition of Mozilla Labs is aimed at sharing ways to expand the capabilities of Firefox. It also showcases technologies that make it easier for anyone interact with virtual reality and the Internet of Things.
+
+### Making it easier to announce software's end of life
+
+Like many things, older versions of software have a use-by date - a date after which it won’t be supported or be compatible with its supporting software or operating systems. That information often gets buried on a project’s website. That’s where [endoflife.date][13] comes in. It’s a repository of information that "aims to overcome the complexity of end of life (EOL) announcements for software."
+
+### Predictions for 2020
+
+What Linux and open source projects and news do you predict being big stories in 2020? Let us know about them in the comments, or send a story proposal to [open@opensource.com][14].
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/open-source-news
+
+作者：[Scott Nesbitt][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/scottnesbitt
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/news-radio-wave-lead_520.png?itok=J86HG1Vg (Radio wave.)
+[2]: https://opensource.com/article/19/9/found-linux-video-gaming
+[3]: https://opensource.com/tags/news
+[4]: https://techcrunch.com/2019/11/05/google-opentitan-secure-chip/
+[5]: https://www.cbronline.com/news/cloudera-open-source
+[6]: http://www.dbta.com/Editorial/News-Flashes/YugaByte-Becomes-100-percent-Open-Source-Under-Apache-20-License-133083.aspx
+[7]: https://www.zdnet.com/article/gnome-and-kde-work-together-on-the-linux-desktop/
+[8]: https://www.forbes.com/sites/jasonevangelho/2019/10/10/system76-will-begin-shipping-2-linux-laptops-with-coreboot-based-open-source-firmware/#3c5fb7294e64
+[9]: https://technical.ly/baltimore/2019/04/19/paris-lutece-open-source-platform-city-services-west-baltimore-community-center-st-francis/
+[10]: https://www.zdnet.com/article/open-source-notify-gov-au-delivered-in-eight-weeks-for-a-cost-of-au150k/
+[11]: https://joinup.ec.europa.eu/collection/open-source-observatory-osor/news/not-having-choose
+[12]: https://betanews.com/2018/12/28/mozilla-labs-is-back/
+[13]: https://endoflife.date/
+[14]: mailto:open@opensource.com
diff --git a/sources/tech/20191229 The best resources for agile software development.md b/sources/tech/20191229 The best resources for agile software development.md
new file mode 100644
index 0000000000..2e504f3d45
--- /dev/null
+++ b/sources/tech/20191229 The best resources for agile software development.md
@@ -0,0 +1,65 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (The best resources for agile software development)
+[#]: via: (https://opensource.com/article/19/12/agile-resources)
+[#]: author: (Leigh Griffin https://opensource.com/users/lgriffin)
+
+The best resources for agile software development
+======
+Read our top articles that highlight the discussion around agile's past,
+present, and what it may look like in the future.
+![Women programming][1]
+
+It has been a great year for agile topics on Opensource.com. As we approach the end of 2019, reviewed our top agile-related articles, as read by you, our readers!
+
+### Small Scale Scrum guide
+
+Opensource.com's six-part guide to [Small Scale Scrum][2] (which I helped co-author) advises smaller teams on how to bring agile into their work. The traditional scrum framework outlined in the official [Scrum Guide][3] recommends a minimum of three people for the framework to realize its full potential. However, it provides no guidance for how teams of one or two people can follow scrum successfully. Our six-part series aims to formalize Small Scale Scrum and examines our experience with it in the real world. The series was received very warmly by our readers—so much such that the six individual articles comprise 60% of our Top 10 list. So, if you haven't already, make sure to download them from our [_Introduction to Small Scale Scrum_ page][2].
+
+### A comprehensive guide to agile project management
+
+Teams following traditional project management approaches, initially skeptical about agile, have warmed up to the agile way of working. Now agile has reached acceptance, and a more flexible, hybrid style has found a home. [_A comprehensive guide to agile project management_][4] by Matt Shealy covers 12 guiding principles of agile project management and is perfect for traditional project managers looking to bring some agility to their projects.
+
+### 4 steps to becoming an awesome agile developer
+
+A DevOps culture has emerged in many modern software teams that embrace agile software development principles that leverage cutting-edge tooling and automation. But this mechanically agile approach does not guarantee that developers are following agile practices in their day-to-day work. In [_4 steps to becoming an awesome agile developer_][5], Daniel Oh gives great tips for increasing your agility by focusing on design thinking, using predictable approaches, putting quality at the center, and continuously learning and exploring. Complementing these methods with your agile tooling will create very flexible and strong agile developers.
+
+### Scrum vs. kanban: Which agile framework is better?
+
+Scrum and kanban are two of the most popular approaches for teams running in an agile manner, and in [_Scrum vs. kanban: Which agile framework is better?_][6] Taz Brown explores the history and purpose of both. While reading this article, a great saying came to my mind: "If the only tool in your toolbox is a hammer, every problem looks like a nail." Knowing when to use kanban and when to use scrum is important, and this article helps show that both have a place, depending on your team, your challenge, and your goals.
+
+### 4 ways developers can have a say in what agile looks like
+
+Developers often have a fear of having a workstyle imposed upon them when the topic of adopting agile comes up. In [_4 ways developers can have a say in what agile looks like_][7], [Clément Verna][8] looks at ways that developers can flip that narrative by helping to determine what agile looks like on their team. Examining the origins and the basics of agile is a great starting point, but the real value is in having metrics to help guide your journey. Knowing what challenges you can expect to have will give you a firm ground to move forward. And making decisions empirically not only empowers teams but gives them a sense of ownership of the journey. Verna's article also examines the importance of putting people over processes and working as a team to achieve your goals.
+
+### Agile now and later
+
+This year, Opensource.com authors created a lot of discussion around agile's past, present, and what it may look like in the future. Thank you to all of them, and be sure to [share your own agile story][9] here in 2020.
+
+A look back at the tools Opensource.com covered in 2014 and 2015 , with updates on new releases,...
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/agile-resources
+
+作者：[Leigh Griffin][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/lgriffin
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/collab-team-pair-programming-code-keyboard2.png?itok=WnKfsl-G (Women programming)
+[2]: https://opensource.com/downloads/small-scale-scrum
+[3]: https://scrumguides.org/scrum-guide.html
+[4]: https://opensource.com/article/19/8/guide-agile-project-management
+[5]: https://opensource.com/article/19/2/steps-agile-developer
+[6]: https://opensource.com/article/19/8/scrum-vs-kanban
+[7]: https://opensource.com/article/19/10/ways-developers-what-agile
+[8]: https://twitter.com/clemsverna
+[9]: https://opensource.com/how-submit-article
diff --git a/sources/tech/20191230 Fixing -VLC is Unable to Open the MRL- Error -Quick Tip.md b/sources/tech/20191230 Fixing -VLC is Unable to Open the MRL- Error -Quick Tip.md
new file mode 100644
index 0000000000..d8bbaf3185
--- /dev/null
+++ b/sources/tech/20191230 Fixing -VLC is Unable to Open the MRL- Error -Quick Tip.md
@@ -0,0 +1,102 @@
+[#]: collector: (lujun9972)
+[#]: translator: ( )
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Fixing “VLC is Unable to Open the MRL” Error [Quick Tip])
+[#]: via: (https://itsfoss.com/vlc-is-unable-to-open-the-mrl/)
+[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
+
+Fixing “VLC is Unable to Open the MRL” Error [Quick Tip]
+======
+
+One of the [VLC tips][1] is to play YouTube and other online videos with [VLC][2]. This could help you [watch online videos with subtitles][3].
+
+But things may not always be simple because at times you’ll encounter this error when trying to open YouTube video with VLC:
+
+**Your input can’t be opened:
+VLC is unable to open the MRL ‘. Check the log for details.**
+
+![VLC error while playing YouTube videos][4]
+
+The thing here is that Google doesn’t want you to use any third party application for watching YouTube because then they cannot collect data properly.
+
+So, they keep changing stuff from their side to make it harder for third party devs to work with YouTube.
+
+Take [youtube-dl][5] for example. You’ll notice that you cannot [download YouTube videos][6] with it all of a sudden and the simplest solution is to have the latest version of youtube-dl installed.
+
+Same goes for VLC. If you [install the latest VLC in Ubuntu][7] or whichever operating system you are using, you probably won’t see this error.
+
+### Fixing “VLC is unable to open the MRL” error
+
+Let me show you the steps to fix this problem for YouTube at least.
+
+Go to this page and use Ctrl+S to save the file from the official GitHub repository of VLC media player:
+
+[Download youtube.lua file][8]
+
+Now, what you need to do is to replace the youtube.luac (mind the ‘c’ in luac) in lib/vlc/lua/playlist directory with this downloaded file.
+
+#### Steps for Linux
+
+If you are using Linux, open the terminal and use the [locate command][9] to find the exact location of youtube.luac file:
+
+```
+locate youtube.luac
+```
+
+When you get the path of the file, you just replace that file with your downloaded file. I trust you to handle this simple task.
+
+For me, it showed the path of the file here:
+
+```
+[email protected]:~$ locate youtube.lua
+/usr/lib/x86_64-linux-gnu/vlc/lua/playlist/youtube.luac
+```
+
+So all I did was to move the downloaded file to this location and replace the content of the file:
+
+```
+sudo cp ~/Downloads/youtube.lua /usr/lib/x86_64-linux-gnu/vlc/lua/playlist/youtube.luac
+```
+
+You should be able to play the YouTube videos in VLC now.
+
+#### Steps for Windows
+
+If you are using Windows, you should follow these steps:
+
+ * Rename the downloaded youtube.lua file to youtube.luac
+ * Now copy this file and paste it to C:\Program Files (x86)\VideoLAN\VLC\lua\playlist\
+
+
+
+That’s it.
+
+If you have trouble with Dailymotion or other video streaming websites, you can download their respective lua files from the VLC repository [here][10] and replace the existing one in your VLC install.
+
+I hope this quick tip fixed the problem with VLC unable to play YouTube videos for you.
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/vlc-is-unable-to-open-the-mrl/
+
+作者：[Abhishek Prakash][a]
+选题：[lujun9972][b]
+译者：[译者ID](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/abhishek/
+[b]: https://github.com/lujun9972
+[1]: https://itsfoss.com/simple-vlc-tips/
+[2]: https://www.videolan.org/index.html
+[3]: https://itsfoss.com/penguin-subtitle-player/
+[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/vlc_error_input_cant_be_played.png?ssl=1
+[5]: https://itsfoss.com/download-youtube-linux/
+[6]: https://itsfoss.com/download-youtube-videos-ubuntu/
+[7]: https://itsfoss.com/install-latest-vlc/
+[8]: https://raw.githubusercontent.com/videolan/vlc/master/share/lua/playlist/youtube.lua
+[9]: https://linuxhandbook.com/locate-command/
+[10]: https://github.com/videolan/vlc/tree/master/share/lua/playlist
diff --git a/translated/tech/20190724 How to make an old computer useful again.md b/translated/tech/20190724 How to make an old computer useful again.md
new file mode 100644
index 0000000000..1df6d5fabd
--- /dev/null
+++ b/translated/tech/20190724 How to make an old computer useful again.md
@@ -0,0 +1,180 @@
+[#]: collector: (lujun9972)
+[#]: translator: (chen-ni)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to make an old computer useful again)
+[#]: via: (https://opensource.com/article/19/7/how-make-old-computer-useful-again)
+[#]: author: (Howard Fosdick https://opensource.com/users/howtechhttps://opensource.com/users/don-watkinshttps://opensource.com/users/suehlehttps://opensource.com/users/aseem-sharmahttps://opensource.com/users/sethhttps://opensource.com/users/marcobravohttps://opensource.com/users/dragonbitehttps://opensource.com/users/don-watkinshttps://opensource.com/users/jamesfhttps://opensource.com/users/seth)
+
+如何把你的老爷机重新利用起来
+======
+按照下面各个步骤，让你的老爷机焕然一新
+![Person typing on a 1980's computer][1]
+
+你的地下室里有一台用来落灰的旧电脑？为什么不把它利用起来呢？如果你常用的电脑坏了，又想用一个比手机更大的屏幕上网，这时候一台备用电脑可能就派上用场了。或者，它也可以充当一台全家人共用的廉价辅助电脑，甚至还可以改造为一台复古游戏机。
+
+哪怕是一台有十余年历史的老爷机，只要选对了软件，也可以胜任很多新电脑能够完成的任务。其中的关键在于，要使用开源软件。
+
+我进行电脑翻新已经有二十年了。在这篇文章里，我会分享一下电脑翻新的技巧。此处讨论的范围包括双核笔记本，以及机龄在 5 到 12 年之间的台式机。
+
+### 检查硬件
+
+第一步是检查硬件是否运转正常。如果在这个环节忽略了一个问题，后面可能会让你非常头疼。
+
+灰尘是电子器件的天敌，所以第一件事应该是打开机箱，清除灰尘。[压缩空气设备][2]这时候可能会派上用场。请注意，进行任何接触电脑的操作时，都应该确保你是[触地][3]的。此外，_避免_ 清洁布与任何物体发生摩擦。即使是一次小到你无法察觉的静电放电，也可能会导致电路损毁。
+
+清洁工作完成之后，关闭机箱，检查是否所有硬件都可以正常工作。需要测试的项目包括：
+
+* 内存
+* 硬盘
+* 主板
+* 外围设备（DVD 驱动器、USB 接口、声卡，等等）
+
+首先，将计算机启动面板（[UEFI][4] 或者是 [BIOS][5]面板）上的诊断测试依次运行一遍。如果不知道按哪个程序功能按键进入你电脑的启动面板，可以参考 [这份列表][6]。
+
+此外，也可以使用诸如 [Hirens BootCD][7] 和 [Ultimate Boot CD][8] 之类的免费资源工具包，进行启动面板覆盖不到的测试。这些资源工具包涵盖了数百个测试程序，并且都是免费的，尽管不都开源。运行这些工具包无需安装任何软件，因为它们都是从 U 盘或者 DVD 驱动器启动的。
+
+测试一定要彻底！对于内存和硬盘来说，基础测试还不够，应该运行深度测试，哪怕是运行一整夜也无妨。只有这样，才能够查出那些不易发现的瞬时故障。
+
+如果发现了问题，可以参考我的[硬件故障排除快速指南][9]，帮你解决最常见的硬件问题。
+
+### 选择软件
+
+电脑翻新的关键在于，根据手头的硬件资源，恰如其分地安装软件。最核心的三种硬件资源分别是：
+
+1. 处理器（核数、速度）
+2. 内存
+3. 显存
+
+可以在启动时的 UEFI/BIOS 面板上，弄清楚你电脑的硬件资源。记得抄下数据，以免遗忘。接下来，可以在 [CPU Benchmark][10] 网站上查看你的处理器，该网站除了提供 CPU 的背景资料，还提供一个 CPU 的性能分数。
+
+了解了硬件性能之后，就可以选择能够在硬件上高效运行的软件了。软件的选择涉及四个重要的层面：
+
+1. 操作系统（OS）
+2. 桌面环境（DE）
+3. 浏览器
+4. 应用
+
+一个优秀的 Linux 发行版可以满足全部四个层面。不要试图使用已经停止维护的 Windows 版本，例如 Windows 8、Vista 或者 XP，哪怕已经安装在电脑上了。恶意软件的 [风险][11] 你是承受不起的。明智的做法是，使用一个更抗病毒的最新版本操作系统。
+
+那 Windows 7 呢？[维护宽限期][12] 至 2020 年 1 月 14 日结束，也就是说，在此日期之前你还可以获得安全补丁，之后就想都别想了。现在正是迁出 Windows 7 的绝佳时机。
+
+Linux 的巨大优势在于，有许多专门为过时硬件设计的[发行版][13]。此外，[桌面环境][14]和操作系统在 Linux 的设计中是分开的，你可以自行选择搭配。这一点非常重要，因为桌面环境对低端系统的性能有很大影响。（对于 Windows 和 MacOS 来说，你选择的操作系统版本决定了桌面环境，没得可选。）
+
+Linux 的另一个好处是，拥有数以千计免费且开源的应用，不需要担心激活或者许可的问题。此外，Linux 是可移植的，可以在不同的分区、硬盘、设备或计算机之间，对操作系统和应用进行复制、移动或克隆。（Windows 则不然，使用注册表将系统捆绑在了所安装的计算机上。）
+
+### 翻新后的电脑能够做什么？
+
+这里讨论的是大约在 2006 年到 2013 年之间生产的双核计算机，尤其是装载了 [Intel 酷睿 2][15] CPU 或 [AMD 速龙 64 X2][16] 系列处理器的计算机。它们的 [CPU 分数][10] 大多在 1000 到 4000 分之间。这种电脑卖不了几个钱，但用在运行轻量级 Linux 软件上，性能还是足够的。
+
+有一点需要注意：你的电脑应该至少拥有 2 GB 内存，如果不够就进行升级。就我翻新过的电脑来说，使用者用到的内存（不包括数据缓存）一般在 0.5 到 2 GB 之间，很少超过 2 GB。如果将内存升级到 2GB，系统就不至于进行 _swap_，即将硬盘当做内存使用。如果想要获得良好性能，这一点十分关键。
+
+以我自己为例，我用来写作这篇文章的是一台有十年机龄的翻新电脑。取下 1 GB 内存条之后，它只剩下了 1 GB 内存，然后就慢得像一只乌龟。用它浏览网页，或者是做类似的事情，都让人感到灰心，甚至痛苦。一旦把内存条重新装回去，有了 2 GB 内存，它就立马回到了可以使用的状态。
+
+一台 2 GB 的双核计算机可以满足大多数人的需求，只要安装的是轻量级发行版和浏览器。你可以用它浏览网页、发送电子邮件、编辑文档和电子表格、观看 YouTube 视频、参与 eBay 拍卖竞标、在社交网络上发帖、听播客、查看相簿、管理家庭收支和个人日程、玩游戏，等等。
+
+### 翻新电脑的局限
+
+那么，这些老爷机又有什么局限呢？由于它们的并发比不上最先进的计算机，所以应该使用轻量级浏览器，同时拦截广告（广告正是让网页加载变慢的罪魁祸首）。如果可以使用虚拟专用网络（VPN）拦截广告，为处理器免除广告加载的负荷，那就再好不过。此外，还需要禁用视频自动播放、Flash 以及网页动效；将浏览器上的标签页控制在少数几个，不要同时打开 20 个；以及下载可以开启/禁用 JavaScript 的浏览器扩展。
+
+让处理器专注于你目前正在做的事情吧，不要同时打开一堆应用，也不要在后台运行很多程序。图像编辑和视频编辑的高级工具可能会很慢；至于运行虚拟机，还是别想了吧。
+
+那游戏呢？开源软件仓库提供了数以千计的游戏。这就是我为什么将显存列为三种核心硬件资源之一。如果你的电脑没有显卡，那很可能只有 32 或者 64 MB 的显存。可以增加一张显卡，将显存提升到 256 或者 512 MB，这样一来，处理器密集型的游戏就会顺畅很多了。如果不确定你的电脑有多少显存，可以参考[这里][17]。请注意，需要确保显卡与电脑的[显卡插槽][18]（AGP、PCI-Express 或者 PCI）相匹配，同时使用正确的[连接线][19]（VGA、DVI 或者 HDMI）。
+
+#### 与 Windows 系统的兼容性如何？
+
+许多人关心 Linux 与 Windows 系统的兼容性如何。首先，对于任何一个 Windows 程序，都有一个 [Linux 的替代版本][20]。
+
+退一步说，即使你真的必须要运行某个特定的 Windows 程序，通常也可以借助 [Wine][21] 在 Linux 上运行。可以在 [Wine 数据库][22] 里查找一下你的应用，看看是否可以在 Wine 上运行，顺便学一些特殊安装技巧。[Winetricks][23] 和 [PlayOnLinux][24] 这两个辅助工具可以帮助你进行安装和配置。
+
+Wine 的另一个优势是可以运行 Windows 的老版本，例如 Vista、XP、ME/98/95 和 3.1。我认识一个家伙，搭建了一台特别赞的游戏电脑，然后用来玩 XP 上的老游戏。借助 [DOSBox][26]，你甚至还可以运行数以千计的[免费 DOS 程序][25]。但是有一点需要注意，如果 Windows 程序可以运行，那么 Windows [病毒][27]也同样可以。你需要保护 Linux 上的 Wine 环境，正如保护任何其他 Windows 环境一样。
+
+对了，与 Microsoft Office 的兼容性又如何呢？我使用的是 LibreOffice，经常编辑并交换 Word 和 Excel 文件，完全没有问题。不过，你应该避免使用隐晦或者过于专业的功能。
+
+### 如何选择发行版？
+
+假设选择了 Linux 作为操作系统，那么你还需要选择桌面环境、浏览器和各种应用。最简单的方法是，安装一个包含了你所需要的一切的发行版。
+
+通过从 [live USB][28] U 盘或者 DVD 启动，你无需安装任何程序，就可以尝试不同的发行版。关于在 Linux 或 Windows 上创建可启动的 Linux 的方法，可以参考 [这里][29]。
+
+我进行电脑翻新的目的是做慈善，所以无法指望电脑使用者具备任何相应知识。我需要的发行版应该具有以下特性：
+
+* 用户友好
+* 具有轻量级界面
+* 自带各种轻量级应用
+* 拥有足够大的软件仓库
+* 历史表现良好
+* 拥有庞大的用户社区和活跃的论坛
+* 通过长期维护版本（而不是滚动发布版本）确保稳定性
+* 更重视可靠性，而不是尖端功能
+* 可以通过图形化用户界面进行设置，而不是只能通过文本文件进行设置
+
+许多发行版都能够满足上面的要求。我曾经尝试成功的有 [Mint/Xfce][30]、[Xubuntu,][31] 和 [Lubuntu][32]。前两个发行版使用 Xfce 桌面环境，第三个使用 LXQt。相比 GNOME、Unity、KDE、MATE 和 Cinnamon 这些桌面环境，运行上面这两种桌面环境只需要[更少][33]的处理器和内存资源。
+
+Xfce 和 LXQt 用起来非常简单，我的客户们之前从未见过 Linux，但是都可以自如使用这些简单的、菜单驱动的用户界面。
+
+对于旧电脑来说，运行最快速、最高效的浏览器是一件非常重要的事情。[很多人觉得][34] Chromium 是最好的浏览器；此外，我还安装了 Firefox Quantum，因为大家比较熟悉它，并且[它的性能][35]可以和 [Chromium 的性能][36]媲美。我还加上了 Opera，因为它速度快，而且有一些独特功能，比如内置的广告拦截，以及免费的 [虚拟专用网络][37]。Opera 是免费的，但并非开源。
+
+无论你使用什么浏览器，一定要拦截广告和追踪器，尽量降低浏览器的负荷。此外，除非得到你的明确批准，否则视频和 Flash 都不应该被允许运行。
+
+至于应用，我使用的是 Mint/Xfce、Xubuntu 和 Lubuntu 自带的轻量级应用。它们足以满足一切需求了。
+
+### 行动起来吧
+
+你是否会对翻新后的电脑感到满意呢？就我来说，我所使用的两台电脑的机龄都已经超过十年了，其中一个装载的是 Intel 双核处理器（[eMachines T5274a][38]），另一个装载的是 AMD 速龙 64 x2 处理器（[HP dc5750][39]），两台电脑都有 2 GB 内存。它们和我的另一台具备四核 i5 处理器和 16 GB 内存 的电脑一样，完全能够胜任我的办公工作。如果说有什么功能是这两台电脑缺失的，那就是运行虚拟机了。
+
+我们生活在一个非常神奇的年代。只需要付出一点努力，就可以将一台机龄在 5 到 12 年之间的旧电脑，翻新为一台具备实用价值的机器。还有什么比这更有趣吗？
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/7/how-make-old-computer-useful-again
+
+作者：[Howard Fosdick][a]
+选题：[lujun9972][b]
+译者：[chen-ni](https://github.com/chen-ni)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/howtechhttps://opensource.com/users/don-watkinshttps://opensource.com/users/suehlehttps://opensource.com/users/aseem-sharmahttps://opensource.com/users/sethhttps://opensource.com/users/marcobravohttps://opensource.com/users/dragonbitehttps://opensource.com/users/don-watkinshttps://opensource.com/users/jamesfhttps://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/1980s-computer-yearbook.png?itok=eGOYEKK- (Person typing on a 1980's computer)
+[2]: https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=compressed+air+for+computers&rh=i%3Aaps%2Ck%3Acompressed+air+for+computers
+[3]: https://www.wikihow.com/Ground-Yourself-to-Avoid-Destroying-a-Computer-with-Electrostatic-Discharge
+[4]: https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface
+[5]: http://en.wikipedia.org/wiki/BIOS
+[6]: http://www.disk-image.com/faq-bootmenu.htm
+[7]: http://www.hirensbootcd.org/download/
+[8]: http://www.ultimatebootcd.com/
+[9]: http://www.rexxinfo.org/Quick_Guide/Quick_Guide_To_Fixing_Computer_Hardware
+[10]: http://www.cpubenchmark.net/
+[11]: https://askleo.com/unsupported-software-really-mean/
+[12]: http://home.bt.com/tech-gadgets/computing/windows-7/windows-7-support-end-11364081315419
+[13]: https://fossbytes.com/best-lightweight-linux-distros/
+[14]: http://en.wikipedia.org/wiki/Desktop_environment
+[15]: https://en.wikipedia.org/wiki/Intel_Core_2
+[16]: https://en.wikipedia.org/wiki/Athlon_64_X2
+[17]: http://www.cyberciti.biz/faq/howto-find-linux-vga-video-card-ram/
+[18]: https://www.onlinecomputertips.com/support-categories/hardware/493-pci-vs-agp-vs-pci-express-video-cards/
+[19]: https://silentpc.com/articles/video-connectors
+[20]: http://wiki.linuxquestions.org/wiki/Linux_software_equivalent_to_Windows_software
+[21]: https://en.wikipedia.org/wiki/Wine_%28software%29
+[22]: https://appdb.winehq.org/
+[23]: https://en.wikipedia.org/wiki/Winetricks
+[24]: https://en.wikipedia.org/wiki/PlayOnLinux
+[25]: https://archive.org/details/softwarelibrary_msdos
+[26]: https://en.wikipedia.org/wiki/DOSBox
+[27]: https://wiki.winehq.org/FAQ#Is_Wine_malware-compatible.3F
+[28]: https://www.howtogeek.com/howto/linux/create-a-bootable-ubuntu-usb-flash-drive-the-easy-way/
+[29]: https://unetbootin.github.io/
+[30]: https://linuxmint.com/
+[31]: https://xubuntu.org/
+[32]: https://lubuntu.me/
+[33]: https://www.makeuseof.com/tag/best-lean-linux-desktop-environment-lxde-vs-xfce-vs-mate/
+[34]: https://www.zdnet.com/article/chrome-is-the-most-popular-web-browser-of-all/
+[35]: https://www.laptopmag.com/articles/firefox-quantum-vs-chrome
+[36]: https://www.zdnet.com/article/just-how-fast-is-firefox-quantum/
+[37]: http://en.wikipedia.org/wiki/Virtual_private_network
+[38]: https://www.cnet.com/products/emachines-t5274/specs/
+[39]: https://community.spiceworks.com/products/7727-hewlett-packard-dc5750-microtower
diff --git a/translated/tech/20191024 Get sorted with sort at the command line.md b/translated/tech/20191024 Get sorted with sort at the command line.md
deleted file mode 100644
index 85d1e816e9..0000000000
--- a/translated/tech/20191024 Get sorted with sort at the command line.md
+++ /dev/null
@@ -1,249 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (lxbwolf)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (Get sorted with sort at the command line)
-[#]: via: (https://opensource.com/article/19/10/get-sorted-sort)
-[#]: author: (Seth Kenlon https://opensource.com/users/seth)
-
-命令行用 sort 进行排序
-======
-按自己的需求重新整理数据 — 用 Linux，BSD 或 Mac 的 terminal — 使用 sort 命令。
-![Coding on a computer][1]
-
-如果你曾经用过数据表应用程序，你就会知道可以按列的内容对行进行排序。例如，如果你有一列价格，你可能希望对它们进行按日期或升序抑或按类别进行排序。如果你熟悉 terminal 的使用，你不会仅为了排序文本数据就去使用庞大的办公软件。这正是 [**sort**][2] 命令的用处。
-
-### 安装
-
-你不必安装 **sort** ，因为它包含在任意 [POSIX][3] 系统里。在大多数 Linux 系统中，**sort** 命令被 GNU 组织捆绑在实用工具集合中。在其他的 POSIX 系统中，像 BSD 和 Mac，默认的 **sort** 命令不是 GNU 提供的，所以有一些选项可能不一样。本文中我尽量对 GNU 和 BSD 两者的实现都进行说明。
-
-### 按字母顺序排列行
-
-**sort** 命令默认会读取文件每行的第一个字符并对每行按字母升序排序后输出。两行中的第一个字符相同的情况下，对下一个字符进行对比。例如：
-
-
-```
-$ cat distro.list
-Slackware
-Fedora
-Red Hat Enterprise Linux
-Ubuntu
-Arch
-1337
-Mint
-Mageia
-Debian
-$ sort distro.list
-1337
-Arch
-Debian
-Fedora
-Mageia
-Mint
-Red Hat Enterprise Linux
-Slackware
-Ubuntu
-```
-
-使用 **sort** 不会改变原文件。sort 仅起到过滤的作用，所以如果你希望按排序后的格式保存数据，你需要用 **>** 或 **tee** 进行重定向。
-
-
-```
-$ sort distro.list | tee distro.sorted
-1337
-Arch
-Debian
-[...]
-$ cat distro.sorted
-1337
-Arch
-Debian
-[...]
-```
-
-### 按列排序
-
-复杂的数据有时候不止需要对每行的第一个字符进行排序。例如，假设有一个动物列表，用可预见的分隔符分隔每一个「字段」（数据表中的「单元格」）。这类由数据表导出的格式很常见，CSV（comma-separated values，以逗号分隔的数据）后缀可以标识这些文件（虽然 CSV 文件不一定用逗号分隔，有分隔符的文件也不一定用 CSV 后缀）。以下数据作为示例：
-
-
-```
-Aptenodytes;forsteri;Miller,JF;1778;Emperor
-Pygoscelis;papua;Wagler;1832;Gentoo
-Eudyptula;minor;Bonaparte;1867;Little Blue
-Spheniscus;demersus;Brisson;1760;African
-Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
-Eudyptes;chrysocome;Viellot;1816;Southern Rockhopper
-Torvaldis;linux;Ewing,L;1996;Tux
-```
-
-对于这组示例数据，你可以用 **--field-separator** （在 BSD 和 Mac 用 **-t**，或 GNU 上可以用简写 **-t** ）设置分隔符为分号（以为示例数据中是用分号而不是逗号，理论上分隔符可以是任意字符），用 **--key**（ 在 BSD 和 Mac 上用 **-k**，或 GNU 上可以用简写 **-k**）选项指定哪个字段被排序。例如，对每行第二个字段进行排序（以 1 开头而不是 0）：
-
-
-```
-sort --field-separator=";" --key=2
-Megadyptes;antipodes;Milne-Edwards;1880;Yellow-eyed
-Eudyptes;chrysocome;Viellot;1816;Sothern Rockhopper
-Spheniscus;demersus;Brisson;1760;African
-Aptenodytes;forsteri;Miller,JF;1778;Emperor
-Torvaldis;linux;Ewing,L;1996;Tux
-Eudyptula;minor;Bonaparte;1867;Little Blue
-Pygoscelis;papua;Wagler;1832;Gentoo
-```
-
-结果有点不容易读，但是 Unix 以构造命令的 **pipe** 方法而闻名，所以你可以使用 **column** 命令美化输出结果。使用 GNU **column**：
-
-
-```
-$ sort --field-separator=";" \
-\--key=2 penguins.list | \
-column --table --separator ";"
-Megadyptes antipodes Milne-Edwards 1880 Yellow-eyed
-Eudyptes chrysocome Viellot 1816 Southern Rockhopper
-Spheniscus demersus Brisson 1760 African
-Aptenodytes forsteri Miller,JF 1778 Emperor
-Torvaldis linux Ewing,L 1996 Tux
-Eudyptula minor Bonaparte 1867 Little Blue
-Pygoscelis papua Wagler 1832 Gentoo
-```
-
-对于初学者可能有点不好理解（但是写起来简单），BSD 和 Mac 上的命令选项：
-
-
-```
-$ sort -t ";" \
--k2 penguins.list | column -t -s ";"
-Megadyptes antipodes Milne-Edwards 1880 Yellow-eyed
-Eudyptes chrysocome Viellot 1816 Southern Rockhopper
-Spheniscus demersus Brisson 1760 African
-Aptenodytes forsteri Miller,JF 1778 Emperor
-Torvaldis linux Ewing,L 1996 Tux
-Eudyptula minor Bonaparte 1867 Little Blue
-Pygoscelis papua Wagler 1832 Gentoo
-```
-
-当然 **key** 不一定非要设为 **2**。任意存在的字段都可以被设为排序的 key。
-
-### 逆序排列
-
-你可以用 **--reverse**（BSD/Mac 上用 **-r**, GNU 也可以用简写 **-r**）选项来颠倒已经排好序的列表。
-
-
-```
-$ sort --reverse alphabet.list
-z
-y
-x
-w
-[...]
-```
-
-你也可以把输出结果通过管道传给命令 [tac][4] 来实现相同的效果。
-
-### 按月排序 (仅 GNU 支持)
-
-理想情况下，所有人都按照 ISO 8601 标准来写日期：年，月，日。这是一种合乎逻辑的指定精确日期的方法，也可以很容易地被计算机理解。也有很多情况下，人类用其他的方式标注日期，用很随意的名字表示月份。
-
-幸运的是，GNU **sort** 命令能识别这种写法，并可以按月份的名称正确排序。使用 **--month-sort (-M)** 选项：
-
-
-```
-$ cat month.list
-November
-October
-September
-April
-[...]
-$ sort --month-sort month.list
-January
-February
-March
-April
-May
-[...]
-November
-December
-```
-
-月份的全称和简写都可以被识别。
-
-### 人类可读的数字排序（仅 GNU 支持）
-
-另一个广泛的人类和计算机的混淆点是数字的组合。例如，人类通常把 ”1024 kilobytes“ 写成 “1KB”，因为人类解析 ”1 KB“ 比 ”1024“ 要容易且更快（数字越大，这种差异越明显）。对于计算机来说，一个 9 KB 的字符串要比诸如 1 MB 的字符串大（尽管 9 KB 是 1 兆的很小一部分）。GNU **sort** 命令提供了**--human-numeric-sort (-h)** 选项来帮助正确解析这些值。
-
-
-```
-$ cat sizes.list
-2M
-12MB
-1k
-9k
-900
-7000
-$ sort --human-numeric-sort
-900
-7000
-1k
-9k
-2M
-12MB
-```
-
-有一些情况例外。例如，16000 bytes 比 1 KB 大，但是 **sort** 识别不了。
-
-
-```
-$ cat sizes0.list
-2M
-12MB
-16000
-1k
-$ sort -h sizes0.list
-16000
-1k
-2M
-12MB
-```
-
-逻辑上来说，这个示例中16000 应该写成 16 KB，所以也不应该全部归咎于GNU **sort** 。只要你确保数字的一致性，**--human-numeric-sort** 可以用一种计算机友好的方式解析成人类可读的数字。
-
-### 随机排序（仅 GNU 支持）
-
-有时候工具也提供了一些与设计初衷相悖的选项。某种程度上说，**sort** 命令提供了对一个文件进行随机排序的能力没有任何意义。这个命令的工作流让这个特性变得很方便。你可以用其他的命令，像 [**shuf**][5] ，或者你可以用现在的命令添加一个选项。不管你认为它是一个臃肿的还是极具创造力的 UX 设计，GNU **sort** 命令提供了对文件进行随机排序的功能。
-
-最纯粹的随机排序格式选项是 **--random-sort** 或 **-R**（不要跟 **-r** 混淆，**-r** 是 **--reverse** 的简写）。
-
-
-```
-$ sort --random-sort alphabet.list
-d
-m
-p
-a
-[...]
-```
-
-每次对文件运行随机排序都会有不同的结果。
-
-### 结语
-
-GNU 和 BSD 命令 **sort** 还有很多功能，所以花点时间去了解这些选项。你会惊异于 **sort** 的灵活性，尤其是当它和其他的 Unix 工具一起使用时。
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/19/10/get-sorted-sort
-
-作者：[Seth Kenlon][a]
-选题：[lujun9972][b]
-译者：[lxbwolf](https://github.com/lxbwolf)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://opensource.com/users/seth
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_laptop_hack_work.png?itok=aSpcWkcl "Coding on a computer"
-[2]: https://en.wikipedia.org/wiki/Sort_(Unix)
-[3]: https://en.wikipedia.org/wiki/POSIX
-[4]: https://opensource.com/article/19/9/tac-command
-[5]: https://www.gnu.org/software/coreutils/manual/html_node/shuf-invocation.html
diff --git a/translated/tech/20191204 Fedora Desktops - Memory Footprints.md b/translated/tech/20191204 Fedora Desktops - Memory Footprints.md
new file mode 100644
index 0000000000..0fe78be674
--- /dev/null
+++ b/translated/tech/20191204 Fedora Desktops - Memory Footprints.md
@@ -0,0 +1,82 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Fedora Desktops – Memory Footprints)
+[#]: via: (https://fedoramagazine.org/fedora-desktops-memory-footprints/)
+[#]: author: (Troy Dawson https://fedoramagazine.org/author/tdawson/)
+
+Fedora 上的桌面环境内存占用测试
+======
+
+![][1]
+
+Fedora 中有 40 多中桌面环境。每种桌面环境都有自己的优点和缺点。通常，根据功能、外观和其他品质，选择桌面是非常个人的偏爱。但有时，你选择的桌面环境还会受到硬件限制。
+
+本文旨在帮助人们根据桌面环境占用的基准内存来比较 Fedora 桌面环境。为了缩小范围，我们仅查看具有正式 Fedora Live 镜像的桌面环境。
+
+### 安装与系统配置
+
+每个桌面环境都安装在自己的 KVM 虚拟机上。每个虚拟机都有 1 个 CPU、4GB 内存、15GB virtio 固态磁盘，以及 RHEL 8.0 kvm 上所有其他标准配置。
+
+用于安装的镜像是标准的 Fedora 31 Live 镜像。对于 GNOME，该镜像是 Fedora 工作站。对于其他桌面，使用了相应的 Spin 版本。未对“糖葫芦”（SOAS）进行测试，因为它不容易安装到本地驱动器上。
+
+用 Live CD 启动虚拟机，然后选择“安装到硬盘”。在安装过程中，仅使用默认值。创建一个 root 用户和一个普通用户。安装并重新启动后，live 镜像已确认不在虚拟 CDROM 中。
+
+每个桌面环境的设置都没有改动。它们每个都以 Live CD 安装中默认的设置运行。每个桌面环境都是通过普通用户登录的。打开了一个终端，在每台虚拟机中都使用 `sudo` 运行了 `dnf -y update`。在更新后，在该 sudo 终端中，每台虚拟机都运行 `/sbin/shutdown -h now` 以关闭。
+
+### 测试方式
+
+每台机器都已启动。桌面环境已通过普通用户登录。打开了三个桌面终端。xterm 从未使用过，始终用的是该桌面环境的终端，例如 konsole。
+
+在一个终端中，启动 `top` 并按下 `M`，以显示按内存排序的进程。在另一个终端中，一个简单的 `while` 循环每 30 秒显示一次 `free -m`。第三个终端闲置。
+
+然后，我等待了 5 分钟。这样就可以让所有启动的服务都启动完成。我记录了最终的 `free` 结果，以及 `top` 中最终的前三名内存使用者。
+
+### 结果
+
+ * Cinnamon
+ * 使用了624 MB
+ * cinnamon 4.8% / Xorg 2.2% / dnfdragora 1.8%
+ * GNOME
+ * 使用了 612 MB
+ * gnome-shell 6.9% / gnome-software 1.8% / ibus-x11 1.5%
+ * KDE
+ * 使用了 733 MB
+ * plasmashell 6.2% / kwin_x11 3.6% / akonadi_mailfil 2.9%
+ * LXDE
+ * 使用了 318 MB
+ * Xorg 1.9% / nm-applet 1.8% / dnfdragora 1.8%
+ * LXQt
+ * 使用了 391 MB
+ * lxqt-panel 2.2% / pcmanfm-qt 2.1% / Xorg 2.1%
+ * MATE
+ * 使用了 465 MB
+ * Xorg 2.5% / dnfdragora 1.8% / caja 1.5%
+ * XFCE
+ * 使用了 448 MB
+ * Xorg 2.3% / xfwm4 2.0% / dnfdragora 1.8%
+
+
+
+### 结论
+
+我会让数字说明一切。
+
+请记住，这些数字来自默认的 Live 安装环境。如果删除或添加服务和功能，则内存使用量将发生变化。但是，如果要根据内存消耗确定桌面环境，这是一个很好的基准。
+
+--------------------------------------------------------------------------------
+
+via: https://fedoramagazine.org/fedora-desktops-memory-footprints/
+
+作者：[Troy Dawson][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://fedoramagazine.org/author/tdawson/
+[b]: https://github.com/lujun9972
+[1]: https://fedoramagazine.org/wp-content/uploads/2019/11/desktop-memory-footprint-816x346.jpg
diff --git a/translated/tech/20191217 5 interview questions every Kubernetes job candidate should know.md b/translated/tech/20191217 5 interview questions every Kubernetes job candidate should know.md
new file mode 100644
index 0000000000..b7a6fa9c1d
--- /dev/null
+++ b/translated/tech/20191217 5 interview questions every Kubernetes job candidate should know.md
@@ -0,0 +1,88 @@
+[#]: collector: (lujun9972)
+[#]: translator: (Morisun029)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (5 interview questions every Kubernetes job candidate should know)
+[#]: via: (https://opensource.com/article/19/12/kubernetes-interview-questions)
+[#]: author: (Jessica Repka https://opensource.com/users/jrepka)
+
+每个 Kubernetes 应聘者应该知道的5个面试题
+======
+如果你要面试Kubernetes相关的应聘者，这里给出了要提问的问题以及这些问题的重要性。
+![Pair programming][1]
+
+面试对面试官及候选人来说都很不容易。最近，我发现面试 Kubernetes 相关工作的候选人似乎尤其困难。为什么呢？一方面，很难找到可以回答他们问题的人。而且，不管回答者回答的怎样，都很难确定他们是否有正确的经验。
+
+跳过这个问题，让我们来看看面试[Kubernetes][2]求职者时应该提问的一些问题。
+
+### Kubernetes 是什么？
+
+我发现这个问题是面试中最好的问题之一。我经常听到有人说“我用Kubernetes工作”，但是当我问道“Kubernetes 是什么时，从来都没有得到过一个满意答案。
+
+我最喜欢克里斯•肖特[Chris Short][3]给出的答案：“Kubernetes 就是带有一些 YAML 文件的 API 。”
+
+虽然他的回答没有错，但我会给你更详细的解释。 Kubernetes 是一个便携式容器编排工具，用于自动执行管理，监控，扩展和部署容器化应用程序。
+
+我认为“用于部署容器化应用程序的编排工具”这个回答可能与你期望的答案差不多了。能回答出这个，我觉得已经很不错了。尽管许多人相信 Kubernetes 可以增加很多，但总的来说，它提供了许多API来增加其核心功能：容器编排。
+
+我认为，这是你在面试中可以提问的最好的问题之一，因为它至少证明了候选人是否知道 Kubernetes 是什么。
+
+### Kubernetes 的 node(节点)和 Pod 有什么区别?
+
+该问题揭示了候选人对 Kubernetes 复杂性的初步了解。它将对话转换为体系结构概述，并可能导向许多有趣的后续细节问题。我已经听到了无数次关于该问题的错误解释了。
+
+[node][4] 是工作计算机。该计算机可以是虚拟机（VM）或物理计算机，具体取决于你是在虚拟机监控程序上运行还是在裸机上运行。该节点包含用于运行容器的服务，包括 kubelet，kube-proxy 和容器运行时。
+
+[pod][5] pod 包括（1）一个或多个具有共享网络（3）和存储（4）的容器（2）以及有关如何运行一起部署的容器的规范。这四个细节都很重要。更进一步，申请人应从技术层面解释，pod 是Kubernetes 可以创建和管理的最小可部署单元，而不是容器。
+
+对于这个问题，我听到的最好的简答是：“node 是计算机，而 pod 是容器中的东西。” 区别很重要。 Kubernetes 管理员的大部分工作是知道什么时间要部署什么，而节点可能非常非常昂贵，具体取决于它们的运行位置。我不希望有人一遍又一遍地部署节点，他们需要做的就是部署一堆Pod。
+
+### kubectl 是什么？ （你怎么发音？）
+
+这个问题是我的优先级中较高的问题之一，但可能与你和你的团队无关。在我的团队中，我们不会使用图形化界面来管理Kubernetes环境，我们使用命令行操作。
+
+那么什么是[kubectl][6]？它是 Kubernetes 的命令行界面。你可以从该界面获取并设置任何内容，从收集日志和事件到编辑部署环境和机密文件。随机提问候选人关于如何使用此工具对测试候选人对 kubectl 的熟悉度是很有帮助的。
+
+你是怎么读的？好吧，你随便吧（对此有很大的分歧），但是我很高兴向你介绍我朋友[Waldo][7]的精彩视频演示。
+
+### 名称空间是什么？
+
+在多次面试中，我都没有得到关于这个问题的答案。我不确定在其他环境中使用的名称空间是否会在我所在的团队经常使用。我在这里给出一个简短的答案：名称空间是Pod中的虚拟集群。这种抽象可以使你将多个虚拟群集保留在各种环境中以此来进行隔离。
+
+### 容器是什么?
+了解 Pod 中正在部署的内容总是有帮助的，因为如果都不知道其中部署的是什么，何谈部署？容器是打包代码及其所有依赖项的软件的标准单元。我收到了两个可以接收的答案，其中包括：a）精简的操作系统映像，以及b）在受限的 OS 环境中运行的应用程序。如果你可以命名使用[Docker][8]以外的其他容器的编排软件（例如你最喜欢的公共云的容器服务），则可以得到加分。
+
+### 其他问题
+如果你想知道为什么我没有在此问题列表中添加更多问题，那么我可以给出一个简单的答案：我所列出的这些问题是在面试候选人时应了解的最基本的问题。接下来的问题应该是基于具体的团队、环境及组织。如果你想知道为什么我没有在此问题列表中添加更多问题，那么我可以给出一个简单的答案：我所列出的这些问题是在面试候选人时应了解的最基本的问题。接下来的问题应该是基于具体的团队、环境及组织。
+
+**[阅读更多：如何准备 Kubernetes 相关的面试？]][9]**
+
+没有两个环境是完全相同的。这也适用于面试中。我在每次面试中都会混合提问。 我也有一个测试面试者的小环境。我经常发现回答问题是最容易的部分，而你所做的工作才是对你的真正的考验。
+
+我给面试官的最后一点建议是：如果你遇到一个很有潜力但没有经验的候选人时，请给他们一个证明自己的机会。如果当初没有人看到我的潜力，没有给我机会的话，我不会拥有今天的知识和经验。
+
+还有哪些重要的问题？请留言告诉我们。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/kubernetes-interview-questions
+
+作者：[Jessica Repka][a]
+选题：[lujun9972][b]
+译者：[Morisun029](https://github.com/译者ID)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/jrepka
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/collab-team-pair-programming-code-keyboard.png?itok=kBeRTFL1 (Pair programming)
+[2]: https://kubernetes.io/
+[3]: https://twitter.com/ChrisShort
+[4]: https://kubernetes.io/docs/concepts/architecture/nodes/
+[5]: https://kubernetes.io/docs/concepts/workloads/pods/pod/
+[6]: https://kubernetes.io/docs/reference/kubectl/kubectl/
+[7]: https://opensource.com/article/18/12/kubectl-definitive-pronunciation-guide
+[8]: https://opensource.com/resources/what-docker
+[9]: https://enterprisersproject.com/article/2019/2/kubernetes-job-interview-questions-how-prepare
diff --git a/translated/tech/20191219 Kubernetes namespaces for beginners.md b/translated/tech/20191219 Kubernetes namespaces for beginners.md
new file mode 100644
index 0000000000..5c1f6267b0
--- /dev/null
+++ b/translated/tech/20191219 Kubernetes namespaces for beginners.md
@@ -0,0 +1,189 @@
+[#]: collector: (lujun9972)
+[#]: translator: (lxbwolf)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Kubernetes namespaces for beginners)
+[#]: via: (https://opensource.com/article/19/12/kubernetes-namespaces)
+[#]: author: (Jessica Cherry https://opensource.com/users/jrepka)
+
+Kubernetes 命名空间入门
+======
+命名空间是什么？你为什么需要它？
+![Ship captain sailing the Kubernetes seas][1]
+
+kubernetes 命名空间是什么？Shakespeare 以前写过，我们声称的命名空间，或者任何其他名字，仍是一个虚拟集群。命名空间，意味着 kubernetes 可以在单个集群上提供多个 kubernetes 的集群，类似一个对其主机进行抽象的虚拟机。[kubernetes 文档][2] 中的解释：
+
+> kubernetes 在一个物理集群上提供了多个虚拟集群。这些虚拟集群被称为命名空间。
+
+你为什么需要命名空间？一句话概括：隔离。
+
+隔离有很多优点，如它提供了安全和干净的环境。如果你是基础设施的所属者，并且为开发者提供环境，隔离就相当重要。你最不需要的就是，一个不熟悉你集群是如何搭建的人去修改系统配置 — 这可能导致所有人都无法登录。
+
+### 初始命名空间
+
+ 一个集群的三个初始命名空间：**default**、**kube-system** 和 **kube-public**。虽然你可以用这三个命名空间作技术部署，但我还是推荐你把这三个命名空间留作系统配置用，而不是你的项目。
+
+ * **Default** 某些部署没有指明命名空间，这样部署可以快速创建一个网格，但如果做了很多错误信息的部署，就很能去清理。我不去修改它，因为它在为某一个目的服务时，会在不止一种情况下误导我。
+ * **Kube-system** 系统相关的所有对象组成的命名空间。任何此命名空间的部署都可能是危险的操作，可能对系统本身造成不可挽回的破坏。没错，我试过；所以我不推荐。
+ * **Kube-public** 所有人可读，但是这个命名空间是为系统保留的。
+
+### 用命名空间来实现隔离
+
+我用了多种方式通过命名空间来实现隔离。我经常用命名空间来把多个用户项目分割到不同的环境。这种方式可以有效防止跨项目的污染，因为命名空间提供了独立的环境。例如，使用者可以安装不同版本的 Jenkins，如果它们的环境变量是在不同的命名空间，就不会冲突。
+
+这种隔离对于清理也很有帮助。如果部署组的多个项目被废弃，你可以用命令 `kubectl delete ns <$NAMESPACENAME>` 一键删除命名空间，清理命名空间内的所有东西。（请确认被删除的是正确的命名空间。我曾经在生产环境删除了错误的命名空间，这很不好。）
+
+如果你是基础设施所有者，请谨慎操作，因为这可能会引发其他团队的的故障或引发其他问题。例如，如果你创建了一个特定的命名空间，里面有 DNS 函数，其他人删除了它，那么命名空间内的所有 pod 和它们运行的应用都会被清空。所有的**删除**操作在真正实施之前都应该由同事（通过 [GitOps][3]）评审一下。
+
+虽然官方文档不建议 [10 人以下团队][2] 使用多个命名空间，但出于架构需要，在我自己的集群上还是用了多个命名空间。集群越干净越好。
+
+### 关于命名空间管理员应该知道的
+
+首先，命名空间不能嵌套。部署只能在一个命名空间中进行。对于版本化项目，你不一定要用命名空间，你可以使用标签来区分有相同名字的版本化应用。命名空间使用配额来为不同的用户划分资源；例如，*某个命名空间最多能有 x 个 node*。最后，所有的命名空间对于资源类型只能使用一个独一无二的名字。
+
+### 命名空间命令操作
+
+你需要安装 [Minikube][4]、 [Helm][5] 和 [kubectl][6] 命令行，才能使用下面的命名空间命令。我的文章 [_安全浏览你的 DevOps 流水线_][7] 中有它们的安装教程，你也可以去每个工程的官方主页去找安装教程。我使用的是最新的 Minikube。手动安装很快，第一次就能成功运行。
+
+获取你的第一组命名空间：
+
+```
+jess@Athena:~$ kubectl get namespace
+NAME STATUS AGE
+default Active 5m23s
+kube-public Active 5m24s
+kube-system Active 5m24s
+```
+
+创建一个命名空间：
+
+```
+jess@Athena:~$ kubectl create namespace athena
+namespace/athena created
+```
+
+现在开发者可以部署到你创建的命名空间；例如，这里是一个简短的 Helm 结构信息：
+
+```
+jess@Athena:~$ helm install teset-deploy stable/redis --namespace athena
+NAME: teset-deploy
+LAST DEPLOYED: Sat Nov 23 13:47:43 2019
+NAMESPACE: athena
+STATUS: deployed
+REVISION: 1
+TEST SUITE: None
+NOTES:
+** Please be patient while the chart is being deployed **
+Redis can be accessed via port 6379 on the following DNS names from within your cluster:
+
+teset-deploy-redis-master.athena.svc.cluster.local for read/write operations
+teset-deploy-redis-slave.athena.svc.cluster.local for read-only operations
+```
+
+获取你的密码：
+
+```
+export REDIS_PASSWORD=$(kubectl get secret --namespace athena teset-deploy-redis -o jsonpath="{.data.redis-password}" | base64 --decode)
+```
+
+连接你的 redis 服务：
+
+1. 运行一个你可以作为客户端用的 Redis pod：
+
+ ```bash
+ kubectl run --namespace athena teset-deploy-redis-client --rm --tty -i --restart='Never' \
+ --env REDIS_PASSWORD=$REDIS_PASSWORD \
+ --image docker.io/bitnami/redis:5.0.7-debian-9-r0 -- bash
+ ```
+
+2. 使用 Redis CLI 连接：
+ ```bash
+ redis-cli -h teset-deploy-redis-master -a $REDIS_PASSWORD
+ redis-cli -h teset-deploy-redis-slave -a $REDIS_PASSWORD
+ ```
+
+从集群外连接你的数据库：
+
+```bash
+kubectl port-forward --namespace athena svc/teset-deploy-redis-master 6379:6379 &
+redis-cli -h 127.0.0.1 -p 6379 -a $REDIS_PASSWORD
+```
+
+现在这一套部署已经完成了，你有一个在命名空间 **test-deploy** 中部署的图表。
+
+查看你的命名空间中有哪些 pod：
+
+
+```
+jess@Athena:~$ kubectl get pods --namespace athena
+NAME READY STATUS RESTARTS AGE
+teset-deploy-redis-master-0 1/1 Running 0 2m38s
+teset-deploy-redis-slave-0 1/1 Running 0 2m38s
+teset-deploy-redis-slave-1 1/1 Running 0 90s
+```
+
+现在，你已经正式把你的应用隔离到了一个命名空间，创建了一个只在内部通信的虚拟集群。
+
+一键删除所有东西：
+
+
+```bash
+jess@Athena:~$ kubectl delete namespace athena
+namespace "athena" deleted
+```
+
+因为这会删除应用的所有内部配置，所以这个删除操作可能会持续一段时间，持续时间取决于你的部署到底有多大。
+
+再次检查一下所有东西是否被删除了：
+
+
+```bash
+jess@Athena:~$ kubectl get pods --all-namespaces
+NAMESPACE NAME READY STATUS RESTARTS AGE
+kube-system coredns-5644d7b6d9-4vxv6 1/1 Running 0 32m
+kube-system coredns-5644d7b6d9-t5wn7 1/1 Running 0 32m
+kube-system etcd-minikube 1/1 Running 0 31m
+kube-system kube-addon-manager-minikube 1/1 Running 0 32m
+kube-system kube-apiserver-minikube 1/1 Running 0 31m
+kube-system kube-controller-manager-minikube 1/1 Running 0 31m
+kube-system kube-proxy-5tdmh 1/1 Running 0 32m
+kube-system kube-scheduler-minikube 1/1 Running 0 31m
+kube-system storage-provisioner 1/1 Running 0 27m
+```
+
+这是一个所有 pod 及它们存在于的已知命名空间的列表。你可以看到，之前创建的应用和命名空间现在已经不在了。
+
+### 命名空间实践
+
+现在我是为了安全使用命名空间，如限制用户的权限。你可以限制所有的东西 — 从哪些角色可以访问命名空间，到命名空间可使用的集群资源（CPU 等）的配额等级。例如，我通过资源配额和基于角色的访问控制（role-based access control，RBAC）配置来确保只有允许的服务账号可以访问命名空间。
+
+对于隔离方面的安全，我不希望我的私人 Jenkins 应用可以通过一个信任的本地网络被当做有公共 IP 地址的安全镜像来访问（我不得不假定，可能会做出妥协）。
+
+如果你很难提前计算出到底要在你的云平台上部署多少 node（就我而言，在把我的私人服务器放到 [segfaulting][8] 之前可以部署多少个 node），那么命名空间在预算方面也很有用。虽然这超出了本文的讨论范围，而且很复杂，但值得你去调研和使用来防止你的集群过分扩展。
+
+### 总结
+
+命名空间是一个很好的隔离项目和应用的方法。本文仅是一个关于命名空间的简短介绍，所以我建议你更深入地研究下命名空间，在你的实践中更多地去使用它们。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/kubernetes-namespaces
+
+作者：[Jessica Cherry][a]
+选题：[lujun9972][b]
+译者：[lxbwolf](https://github.com/lxbwolf)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/jrepka
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/ship_captain_devops_kubernetes_steer.png?itok=LAHfIpek (Ship captain sailing the Kubernetes seas)
+[2]: https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/
+[3]: https://www.weave.works/blog/gitops-operations-by-pull-request
+[4]: https://kubernetes.io/docs/tasks/tools/install-minikube/
+[5]: https://helm.sh/
+[6]: https://kubernetes.io/docs/tasks/tools/install-kubectl/
+[7]: https://opensource.com/article/19/7/security-scanning-your-devops-pipeline
+[8]: https://en.wikipedia.org/wiki/Segmentation_fault
diff --git a/translated/tech/20191220 Why Vim fans love the Herbstluftwm Linux window manager.md b/translated/tech/20191220 Why Vim fans love the Herbstluftwm Linux window manager.md
new file mode 100644
index 0000000000..cba33f5166
--- /dev/null
+++ b/translated/tech/20191220 Why Vim fans love the Herbstluftwm Linux window manager.md
@@ -0,0 +1,104 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Why Vim fans love the Herbstluftwm Linux window manager)
+[#]: via: (https://opensource.com/article/19/12/herbstluftwm-linux-desktop)
+[#]: author: (Seth Kenlon https://opensource.com/users/seth)
+
+为什么 Vim 爱好者喜欢 Herbstluftwm Linux 窗口管理器
+======
+本文是 24 天 Linux 桌面特别系列的一部分。如果你是Vim爱好者，请试试 Herbstluftwm，这是一个受到 ”Vim 方式“启发的基于平铺的 Linux 窗口管理器。
+![OpenStack source code \(Python\) in VIM][1]
+
+每个人都喜欢 Vim（除了 Dvorak 和 Emacs 用户）。Vim 非常流行，以至于有整个 Web 浏览器都使用 Vim 键绑定来浏览网页，非常流行的 [Zsh][2] 终端仿真器中的 Vim 模式，甚至是文本编辑器。 还有一个名为 [herbstluftwm][3] 的窗口管理器，它部分模仿了 “Vim 方式”。Herbstluftwm 取消了窗口，在程序载入和使用时使用平铺或者象限代替。 你可以使用键盘（**Alt+h**、**Alt+j**、**Alt+k** 和 **Alt+l**）从一个平铺块移动到另一个平铺块。
+
+![Herbstluftwm][4]
+
+从发行版软件仓库安装 Herbstluftwm。安装后，请退出当前桌面会话，以便可以登录到新会话。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，具体取决于你的设置）将继续登录到以前的桌面，因此在登录之前必须覆盖它。
+
+在 GDM 中：
+
+![][5]
+
+在 SDDM 中：
+
+![][6]
+
+### Herbstluftwm 桌面之旅
+
+第一次登录 Herbstluftwm 时，你只会看到绿屏，边缘有深绿色边框。你所看到的是初始平铺，其中没有加载任何应用程序。要启动默认应用，请按 **Alt+回车**。
+
+文档中强调使用 **$HOME/.config/herbstluftwm/autostart** 作为登录时启动应用的配置文件。对于不必在每次登录时启动的应用，可以使用 xterm 作为启动守护进程。与往常一样，在命令将 shell 的控制权返回给你后加一个 **amp;** 符号。例如，要启动 Emacs：
+
+
+
+```
+`% emacs &`
+```
+
+这将在新平铺中启动 Emacs 窗口，然后返回命令行。
+
+![Emacs running in Herbstluftwm][7]
+
+#### 切换平铺
+
+要从一个平铺块移动到另一个平铺块，请使用经典的 **h**、**j**、**k** 或 **l** 与 **Alt** 的 Vim 导航组合键。例如，要从终端切换到其下方平铺中的应用（即屏幕底部），请按 **Alt+j**。要返回，请按 **Alt+k**。左移和右移分别为 **Alt+h** 和 **Alt+l**。
+
+#### 分割屏幕
+
+你可以使用 **Alt+o** 垂直分割屏幕，使用 **Alt+u** 水平分割屏幕。
+
+要删除空白平铺块，请移动到该平铺块，然后按 **Alt+r**。
+
+### 配置 herbstluftwm
+
+除了 **Alt** 键绑定外，你还可通过 **herbstclient** 命令与 Herbstluftwm 进行通信。此命令可以在 shell 中交互，或者你可在配置文件中保留你的首选项。
+
+你可以查看 Herbstluftwm 中的所有可用属性：
+
+
+```
+`$ herbstclient attr`
+```
+
+Herbstluftwm 的默认行为在默认配置文件中定义，你可以将其复制到家目录并进行修改。启动后，Herbstluftwm 执行配置文件中包含的命令。例如，你觉得使用以 **Alt** 为中心的键绑定很笨拙（它传统上是应用内保留快捷键），那你可以在配置文件中更改触发 Herbstluftwm 操作的键：
+
+
+```
+% mkdir ~/.config/herbstluftwm
+% cp /usr/xdg/herbstluftwm/autostart \
+~/.config/herbstluftwm
+% sed -i 's/Mod=Mod1/Mod=Mod4/' ~/.config/herbstluftwm
+% herbstclient reload
+```
+
+这将使 Herbstluftwm 的修饰键更改为 Super 键（”Windows“或 ”Tux“ 键，具体取决于你的键盘）。
+
+使用自动启动文件，你可以设置自定义键绑定，为特定类型的应用创建标签，以便以一致的方式平铺应用，并执行更多操作。
+
+### 为何你要尝试 herbstluftwm
+
+Herbstluftwm 是一个平铺窗口管理器的很好例子。它默认平铺窗口，并允许用户定义全局规则例外。它使用类似 Vim 的导航，但可以快速简单地覆盖它。你可能是你一直在寻找的平铺管理器，所以请尽快尝试一下。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/herbstluftwm-linux-desktop
+
+作者：[Seth Kenlon][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/seth
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/openstack_python_vim_2.jpg?itok=4fza48WU (OpenStack source code (Python) in VIM)
+[2]: https://opensource.com/article/19/9/getting-started-zsh
+[3]: https://herbstluftwm.org
+[4]: https://opensource.com/sites/default/files/uploads/advent-herbsluftwm.png (Herbstluftwm)
+[5]: https://opensource.com/sites/default/files/advent-gdm_1.jpg
+[6]: https://opensource.com/sites/default/files/advent-kdm_0.jpg
+[7]: https://opensource.com/sites/default/files/uploads/advent-herbsluftwm-emacs.jpg (Emacs running in Herbstluftwm)
diff --git a/translated/tech/20191221 Pop-_OS vs Ubuntu- Which One is Better.md b/translated/tech/20191221 Pop-_OS vs Ubuntu- Which One is Better.md
new file mode 100644
index 0000000000..3693d00e22
--- /dev/null
+++ b/translated/tech/20191221 Pop-_OS vs Ubuntu- Which One is Better.md
@@ -0,0 +1,154 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (Pop!_OS vs Ubuntu: Which One is Better?)
+[#]: via: (https://itsfoss.com/pop-os-vs-ubuntu/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+Pop!_OS 与 Ubuntu：哪个更棒？
+======
+
+好吧，你可能会发现从[最佳 Linux 发行版][1]列表中选择一个发行版很容易，但是，将两个类似的 Linux 发行版进行比较通常会令人困惑，就像 Pop!_OS 与 Ubuntu 一样。
+
+有趣的是，Pop!\_OS 基于 [Ubuntu][2]。那么，Pop!\_OS 和 Ubuntu 之间有什么区别呢？为什么要从中选择一个呢？
+
+在本文中，我将比较 Pop!_OS 和 Ubuntu（两者都是我的最爱）。
+
+**注意：**你可能会发现一些武断的观点，而本文只是一份比较的参考。随着 Linux 发行版的不断开发和更新，随着时间的流逝，很多事情都会改变。
+
+### 比较 Ubuntu 和 Pop!_OS
+
+![Pop!_OS Vs Ubuntu][3]
+
+发现相似之处可帮助你区分其他差异之处。因此，让我们从一些明显的相似之处开始。
+
+就像我提到的，Pop!\_OS 是基于 Ubuntu 之上的 Linux 发行版。因此，当你使用 Pop!_OS 时，你将获得使用 Ubuntu 的所有好处（从技术上说，其核心是一样的）。
+
+它们都默认带有 [GNOME 桌面环境][4]，因此它们具有相似的用户界面（UI）。
+
+在不讨论所有底层差异的情况下，我将在这里重点介绍一些重要的差异。
+
+#### 用户体验及主题
+
+![Pop!_OS][5]
+
+许多用户认为 Pop!_OS 只是具有不同外观的 Ubuntu。
+
+根据我的经验，我觉得这并非完全正确。
+
+是的，它们俩都很喜欢 [GNOME 桌面环境][4] —— 但是，Pop!_OS 让人感觉更加优美。
+
+除了外观之外，[Ubuntu 还通过添加程序坞和其他一些小花巧来定制了 GNOME 的体验][6]。如果你喜欢定制的 GNOME 体验，可能会发现它更好。
+
+但是，如果你更喜欢纯粹的 GNOME 体验，默认情况下 Pop!_OS 会为你提供。
+
+在你亲自尝试之前，我无法说服你。但是，Pop!_OS 中的总体配色方案、图标和主题可以说是令人愉悦的高级用户体验。
+
+这可能是一个主观的事情，但这是我所观察到的。你还可以查看 Ubuntu 19.10 的视频教程，亲自感受一下。
+
+#### 易于安装第三方应用
+
+![Pop Os PPA][7]
+
+Ubuntu 非常重视 Snap 软件包。这增加了它提供的应用程序的数量。
+
+但是 Snap 软件包存在一些重要的问题。它们占用了过多的磁盘空间，并且启动要花费大量的时间。
+
+这就是为什么我更喜欢使用应用程序的 APT 版本的原因。
+
+我为什么要说这个呢？
+
+因为 Pop!_OS 具有其[自己的官方 PPA][8]，并在默认情况下已启用。你会在此处找到一些有用的应用程序，例如 Android Studio、TensorFlow。无需下载 Android Studio 的 1GB 大的 Snap 程序包。只需使用 [apt-get install][9]就可以了。
+
+#### 预装应用
+
+![Ubuntu installation slideshow][10]
+
+对于某些人来说，它可能不是最大的问题，但是拥有大量预安装的应用程序可能会影响体验和性能。即使不影响性能，某些用户也只喜欢较少的预装应用程序。
+
+与 Ubuntu 相比，Pop!_OS 捆绑了更少的默认应用程序（潜在地减少了胖软件）。
+
+再一次提醒，这是主观的看法。如果你希望预安装更多应用程序，则可以考虑使用 Ubuntu 而不是 Pop!_OS。
+
+#### Snap 软件包支持
+
+![][11]
+
+对于熟悉 Snap 程序包的用户来说，Ubuntu 的软件中心是比 Pop!_OS 商店更好的解决方案，因为你可以在软件中心中列出快照程序包。
+
+你无法在软件中心中过滤快照包，但是当你在软件中心中发现一个 Snap 包（查看应用程序来源的详细信息为“ Snap store ”/“Snapcraft”）时安装它就更容易了。
+
+如果你感到困惑，Pop!\_OS 也确实支持快照包。但是，你不会在 Pop!_OS 商店中找到它们，这是唯一的区别。
+
+如果不确定什么是 Snap 软件包及其功能，可以查看我们的文章[在 Linux 上安装 Snap 应用][12]。
+
+#### 单独的 NVIDIA/AMD ISO 文件
+
+![ISOs][13]
+
+从技术上讲，它不是内部比较的一部分，而是某些用户关心的一个因素。
+
+因此，值得强调的是 Pop!_OS 提供了单独的 ISO。一个用于带 NVIDIA 显卡的系统，另一个用于带/不带 AMD 显卡的系统。
+
+使用 Ubuntu 19.10，你可以在 Ubuntu ISO 上获得 NVIDIA 驱动程序，但 AMD 显卡没有这个。
+
+#### 可靠性与问题
+
+毫无疑问，这两个[发行版都适合初学者][14]，并且相当可靠。如果你想要更好的可靠性和更少的问题，则可能希望一直用长期支持（LTS）版本。
+
+当出现新版本的 Ubuntu 时，Pop!_OS 将在其上开发，并有可能解决用户在 Ubuntu 原始发行版上遇到的问题，然后再进行新的升级。这给他们带来了一点优势，但这没什么实质性的不同，因为这些修复最终都可以运用于 Ubuntu。
+
+#### 性能
+
+性能将高度取决于你所安装的内容以及所安装的硬件配置。
+
+除非你有一个超级旧的系统，否则这两个发行版似乎都表现良好。
+
+我的机器是 i5-7400 处理器和 16GB 的 RAM（带有 GTX 1050ti 显卡），我发现两种发行版上的体验都足够好。
+
+当然，你可以手动进行一些优化调整以满足要求——无论它们中的哪个不满足你的硬件配置。
+
+但是，如果你想使用 System76 笔记本电脑，那么 Pop!\_OS 将可以证明自己是 [Linux 领域的苹果][15]，因为 Pop!_OS 是针对其硬件量身定制的，与 Ubuntu 有所不同。
+
+#### 硬件兼容性
+
+在比较其他 Linux 发行版时，这绝对是要考虑的事情。但是，在这种情况下，实际上并没有太大的区别。
+
+你可能会考虑 Pop!_OS 一直在使用较新的硬件配置，因为他们主要是为他们的笔记本电脑量身定制具有各种配置的 OS。而且，这只是一个观察，而不是事实。
+
+### 结语
+
+我知道在不亲自尝试的情况下从两个流行的 Linux 发行版中选择一个并不容易。如果可能的话，我建议你在进行比较的同时尝试两者，以供参考。
+
+你在这两者之间有何选择？我在比较中错过了什么吗？在下面的评论中让我知道。
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/pop-os-vs-ubuntu/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://itsfoss.com/best-linux-distributions/
+[2]: https://ubuntu.com/
+[3]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/pop_os_vs_ubuntu.png?ssl=1
+[4]: https://www.gnome.org/
+[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/11/pop-os-UI.jpg?ssl=1
+[6]: https://itsfoss.com/gnome-tricks-ubuntu/
+[7]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/pop-os-ppa.jpg?ssl=1
+[8]: https://launchpad.net/~system76/+archive/ubuntu/pop/
+[9]: https://itsfoss.com/apt-get-linux-guide/
+[10]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/08/install-ubuntu-linux-on-intel-nuc-14_tutorial.jpg?resize=800%2C516&ssl=1
+[11]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/11/snapcraft.jpg?ssl=1
+[12]: https://itsfoss.com/install-snap-linux/
+[13]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/11/iso-amd-nvidia-pop-os.jpg?ssl=1
+[14]: https://itsfoss.com/best-linux-beginners/
+[15]: https://www.phoronix.com/scan.php?page=news_item&px=System76-Integrated-Vision
diff --git a/translated/tech/20191224 App Highlight- Falkon Open Source Web Browser from KDE.md b/translated/tech/20191224 App Highlight- Falkon Open Source Web Browser from KDE.md
new file mode 100644
index 0000000000..18d42af58a
--- /dev/null
+++ b/translated/tech/20191224 App Highlight- Falkon Open Source Web Browser from KDE.md
@@ -0,0 +1,121 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (App Highlight: Falkon Open Source Web Browser from KDE)
+[#]: via: (https://itsfoss.com/falkon-browser/)
+[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
+
+应用推荐：来自 KDE 的 Falkon 开源 Web 浏览器
+======
+
+_**它以前称为 Qupzilla，Falkon 是基于 QtWebEngine 的 Web 浏览器。在本周的“应用推荐”中，我们来看看这个开源软件。**_
+
+### Falkon：适用于 Linux（和 Windows）的开源 Web 浏览器
+
+![][1]
+
+首先，[Falkon][2] 不是新的 Web 浏览器。它自 2010 年以来一直在开发中，但被称为 Qupzilla。
+
+2017 年，QupZilla 移到 KDE 旗下，并更名为 Falkon。处于 KDE 旗下意味着项目会按照 KDE 标准积极维护。
+
+它使用 [QtWebEngine][3] 渲染引擎，这是 Chromium 核心的简化版本。
+
+在本文中，我将仔细研究它提供的功能以及与 Linux 上其他主流 Web 浏览器的不同之处。
+
+### Falkon 浏览器的功能
+
+我认为它可能不是流行的浏览器，但我发现它足以浏览现代 Web 服务。
+
+让我重点介绍 Falkon 的主要功能，如果你觉得它很有趣，请尝试一下。
+
+#### 简单的用户界面
+
+![][4]
+
+我知道这不完全是一项“功能”，但是用户体验 （UX） 至关重要。尽管是轻量级的浏览器，但你会拥有一个不错的界面。你不会觉得使用的是 2000 年早期的浏览器。
+
+#### AdBlock 扩展
+
+![][5]
+
+它附带了 AdBlock 扩展程序，如果你想在浏览网站时摆脱广告，它大的效果很好。你还可以自定义 AdBlock 扩展的行为。
+
+#### DuckDuckGo 作为默认搜索引擎
+
+如果你不喜欢使用 Google，那么最好将[主打隐私的搜索引擎][6]之一设为默认搜索引擎。
+
+#### 会话管理器
+
+![][7]
+
+Falkon 在浏览器菜单的可用选项中包含了一个有用的会话管理器。你可以用它还原特定的近期会话，这应该能派上用场。
+
+#### 扩展支持
+
+![][8]
+
+它确实支持添加扩展，但你不能从 Chrome/Firefox 插件市场添加扩展。你只能选择有限的一组扩展。
+
+#### 主题支持
+
+Falkon 还允许你在某种程度上自定义外观。如果要更改浏览器的外观，可以尝试一下。
+
+![][9]
+
+#### 其他基本设置
+
+![][10]
+
+我还尝试了其他设置/功能，例如添加书签或管理密码。
+
+或者，管理网页的通知。
+
+我还试了 YouTube，没有任何问题。
+
+当然，这不是一个详尽的评测。但是，Falkon 确实拥有浏览器中需要的所有基本功能（除非你有特定要求）。
+
+### 安装 Falkon 浏览器
+
+你可以在软件中心轻松找到 Falkon 浏览器。
+
+如果没有，你可以从它的[官方下载页面][11]中找到 Flatpak/Snap 包。你还可以在下载页面上找到 Windows 的安装程序。
+
+[Download Falkon Browser][11]
+
+**总结**
+
+作为 KDE 产品，Falkon 是为 KDE 桌面环境量身定制的。一些 KDE 发行版（例如 OpenMandriva）使用 Falkon 作为默认的 Web 浏览器。
+
+Falkon 浏览器适合那些正在寻求轻巧且功能丰富的 Web 浏览器的人。值得尝试的一个替代是 [Midori][12]。
+
+我认为，除非你需要大量的扩展、跨平台同步并且需要访问某些特定于浏览器的网站，不然它是一个很好的替代浏览器，。
+
+你如何看待 Falkon 浏览器？请在下面的评论中让我知道你的想法。
+
+--------------------------------------------------------------------------------
+
+via: https://itsfoss.com/falkon-browser/
+
+作者：[Ankush Das][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://itsfoss.com/author/ankush/
+[b]: https://github.com/lujun9972
+[1]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/falkon-browser-screenshot.jpg?ssl=1
+[2]: https://www.falkon.org/
+[3]: https://wiki.qt.io/QtWebEngine
+[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/falkon-browser.png?ssl=1
+[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/falkon-adblock.jpg?ssl=1
+[6]: https://itsfoss.com/privacy-search-engines/
+[7]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/session-manager-falkon.jpg?ssl=1
+[8]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/falkon-browser-extensions.png?ssl=1
+[9]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/12/falkon-browser-theme.png?ssl=1
+[10]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/12/falkon-browser-preference.png?ssl=1
+[11]: https://www.falkon.org/download/
+[12]: https://itsfoss.com/midori-browser/
diff --git a/translated/tech/20191227 10 resources to boost your Git skills.md b/translated/tech/20191227 10 resources to boost your Git skills.md
new file mode 100644
index 0000000000..eee2be8848
--- /dev/null
+++ b/translated/tech/20191227 10 resources to boost your Git skills.md
@@ -0,0 +1,57 @@
+[#]: collector: (lujun9972)
+[#]: translator: (wxy)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (10 resources to boost your Git skills)
+[#]: via: (https://opensource.com/article/19/12/git-resources)
+[#]: author: (Joshua Allen Holm https://opensource.com/users/holmja)
+
+10 个提高 Git 技能的资源
+======
+
+> 年末总结一下 Git 的最佳表现。以下是在新的一年中以新奇的方式使用 Git 的十篇文章。
+
+![open source button on keyboard][1]
+
+快到 2019 年底了，是时候回顾一下我们今年发表的有关 Git 的前 10 篇文章了。
+
+这些文章包括从用例和教程到一些非常有趣的（甚至有些非常规的）使用 Git 的方法。所有这些文章都可以帮助你提高 Git 技能，但是，如果你确实需要 Git 入门介绍，请务必查看我们的《[Git 入门：术语入门][2]》文章，并下载我们的 [Git 备忘单][3]。
+
+1. Molly de Blanc 写的《[GNOME 如何使用 Git][4]》考察了 GNOME 项目采用的自托管 GitLab 实例的做法，该实例作为 GNOME 项目集中保存为 GNOME 做出的贡献的位置。De Blanc 从事于非编码职位，因此她的文章还探讨了切换到 GitLab 如何使主要角色不是编写代码的贡献者受益。
+2. Ahmad Awais 写的《[Emoji-Log：编写 Git 提交信息的新方法][5]》解释了如何使用 Emoji-Log（一种直白的、开源的 Git 提交日志标准）来编写更好、更用户友好的 Git 提交消息。本文概述了 Emoji-Log 背后的理论以及可添加到 `.bashrc`、`.zshrc` 或 `.gitconfig` 中的配置示例，以便你快速开始使用 Emoji-Log。
+3. 在《[用 Git 管理你的每日行程][6]》中，Seth Kenlon 解释了如何使用 Git 来管理日历。通过结合 Org 模式、Git 和其他一些工具，Kenlon 描述了如何创建可在设备之间同步的基于 Git 的日历工作流。
+4. 《[用 Git 作为聊天应用的后端][7]》，Seth Kenlon 探索了另一种使用 Git 的非常规方式。在本文中，他探讨了 GIC，这是一个用 Node.js 编写的聊天客户端，其中 Git 用作后端数据库。GIC 是一个概念验证模型，不是供产品环境使用的东西，但是它提供了一个有趣的示例，说明了使用 Git 的真正独特方法。
+5. Alan Formy-Duval 的《[Git 学习实用练习][8]》是一份他为提高 Git 技能而努力的编年史。他分享了自己的经验，以使其他人受益于他所学，而 Git 新手将从这篇对 Git 核心功能的出色概述中受益匪浅。
+6. 《[用 Git 帮助写作者更好地完成工作][9]》的作者 Seth Kenlon 着眼于写作者如何从基于 Git 的工作流中受益。本文介绍了如何使用 Git 和 Atom 利用 Markdown 进行书写。通过遵循本文中的示例，写作者可以轻松地将复杂的修订控制系统添加到其编写工作流中。
+7. Sachin Patil 在《[如何使用 Magit 管理 Git 项目][10]》中，解释了如何使用 Emacs 的 Magit 扩展来管理 Git 存储库。本文提供了有关如何在 Emacs 中执行一系列关键 Git 任务的清晰示例。这些示例由说明各种任务的屏幕截图支持。
+8. 《[把“点文件”放到版本控制中][11]》的作者 Matthew Broberg 演示了如何使用 Git 存储放在主目录中的点文件。将你的点文件存储在 Git 存储库中，可以更轻松地在计算机之间共享系统配置，并且，如果你愿意的话，也可以与其他人共享配置。这篇文章也有什么不要共享的警告，因为共享错误的点文件会暴露给其他人。
+9. Austin Dewey 的《[4 种用于 Git 加密的机密管理工具][12]》在本文中比较了 Git-crypt、BlackBox、SOPS 和 Transcrypt，研究了在 Git 中存储机密的工具。本文涵盖四个主要领域：支持的加密类型、每个项目的目标、项目的工作流和差异以及其他功能。
+10. Seth Kenlon 的《[使用 Git 管理 Git 服务器][13]》解释了如何使用 Gitolite 管理 Git 服务器。Gitolite 是使用 Git 来管理 Git 服务器的“管理杂项的后端应用程序”。本文演示了如何安装、配置和使用 Gitolite，并提供了清晰的示例详细说明了该过程的每个步骤。
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/19/12/git-resources
+
+作者：[Joshua Allen Holm][a]
+选题：[lujun9972][b]
+译者：[wxy](https://github.com/wxy)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://opensource.com/users/holmja
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/button_push_open_keyboard_file_organize.png?itok=KlAsk1gx (open source button on keyboard)
+[2]: https://opensource.com/article/19/2/git-terminology
+[3]: https://opensource.com/downloads/cheat-sheet-git
+[4]: https://opensource.com/article/19/10/how-gnome-uses-git
+[5]: https://linux.cn/article-10627-1.html
+[6]: https://linux.cn/article-11320-1.html
+[7]: https://linux.cn/article-11342-1.html
+[8]: https://opensource.com/article/19/5/practical-learning-exercise-git
+[9]: https://linux.cn/article-11499-1.html
+[10]: https://opensource.com/article/19/1/how-use-magit
+[11]: https://linux.cn/article-11419-1.html
+[12]: https://opensource.com/article/19/2/secrets-management-tools-git
+[13]: https://opensource.com/article/19/4/server-administration-git