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published/20151117 How bad a boss is Linus Torvalds.md
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Linus Torvalds 是一个糟糕的老板吗？
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================================================================================
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*1999 年 8 月 10 日，加利福尼亚州圣何塞市，在 LinuxWorld Show 上 Linus Torvalds 在一个坐满 Linux 爱好者的礼堂中发表了一篇演讲。图片来自：James Niccolai*
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**这取决于所处的领域。在软件开发的世界中，他也是个普通人。问题是，这种情况是否应该继续下去？**
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Linus Torvalds 是 Linux 的发明者，我认识他超过 20 年了。我们不是密友，但是我们欣赏彼此。
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最近，因为 Linus Torvalds 的管理风格，他正遭到严厉的炮轰。Linus 无法忍受胡来的人。“代码的质量有多好？”是他在 Linux 内核的开发过程中评判人的一种方式。
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没有什么比这个更重要了。正如 Linus 今年（2015年）早些时候在 Linux.conf.au 会议上说的那样，“我不是一个友好的人，我也不在意你。对我重要的是『[我所关心的技术和内核][1]』。”
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现在我也可以和这种只关心技术的人打交道了。如果你不能，你应当避免参加 Linux 内核会议，因为在那里你会遇到许多有这种精英思想的人。这不代表我认为在 Linux 领域所有东西都是极好的，并且不应该受到其他影响而带来改变。我能够和一个精英待在一起；而在一个男性做主导的大城堡中遇到的问题是，女性经常受到蔑视和无礼的对待。
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这就是我看到的最近关于 Linus 管理风格所引发争论的原因 -- 或者更准确的说，他对于个人管理方面是完全冷漠的 -- 就像是在软件开发世界的标准操作流程一样。与此同时，我看到了揭示了这个事情需要改变的另外一个证据。
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第一次是在 [Linux 4.3 发布][2]的时候出现的这个情况，Linus 使用 Linux 内核邮件列表来狠狠的数落了一个插入了一些网络方面的代码的开发者——这些代码很“烂”，“[生成了如此烂的代码][3]。这看起来太糟糕了，并且完全没有理由这样做。”他继续咆哮了半天。这里使用“烂”这个词，相对他早期使用的“愚蠢的”这个同义词来说还算好的。
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但是，事情就是这样。Linus 是对的。我读了代码后，发现代码确实很烂，并且开发者只是为了用新的“overflow_usub()” 函数而用的。
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现在，一些人把 Linus 的这种谩骂的行为看作他脾气不好而且恃强凌弱的证据。我见过一个完美主义者，在他的领域中，他无法忍受这种糟糕。
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许多人告诉我，这不是一个专业的程序员应当有的行为。群众们，你曾经和最优秀的开发者一起工作过吗？据我所知道的，在 Apple，Microsoft，Oracle 这就是他们的行为。
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我曾经听过 Steve Jobs 攻击一个开发者，就像要把他撕成碎片那样。我也被一个 Oracle 的高级开发者攻击一屋子的新开发者吓到过，就像食人鱼穿过一群金鱼那样。
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在 Robert X. Cringely 关于 PC 崛起的经典书籍《[意外帝国（Accidental Empires）][5]》，中，他这样描述了微软的软件管理风格，比尔·盖茨像计算机系统一样管理他们，“比尔·盖茨的是最高等级，从他开始每一个等级依次递减，上级会向下级叫嚷，刺激他们，甚至羞辱他们。”
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Linus 和所有大型的商业软件公司的领导人不同的是，Linus 说在这里所有的东西是向全世界公开的。而其他人是在自己的会议室中做东西的。我听有人说 Linus 在那种公司中可能会被开除。这是不可能的。他会处于他现在所处的地位，他在编程世界的最顶端。
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但是，这里有另外一个不同。如果 Larry Ellison （Oracle 的首席执行官）向你发火，你就别想在这里干了。如果 Linus 向你发火，你会在邮件中收到他的责骂。这就是差别。
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你知道的，Linus 不是任何人的老板。他完全没有雇佣和解聘的权利，他只是负责着有 10000 个贡献者的一个项目而已。他仅仅能做的就是从心理上伤害你。
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这说明，在开源软件开发圈和商业软件开发圈中同时存在一个非常严重的问题。不管你是一个多么好的编程者，如果你是一个女性，你的这个身份就是对你不利的。
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这种情况并没有在 Sarah Sharp 的身上有任何好转，她现在是一个 Intel 的开发者，以前是一个顶尖的 Linux 程序员。[在她博客上10月份的一个帖子中][4]，她解释道：“我最终发现，我不能够再为 Linux 社区做出贡献了。因为在那里，我虽然能够得到技术上的尊重，却得不到个人的尊重……我不想专职于同那些有着轻微的性别歧视或开同性恋玩笑的人一起工作。”
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谁会责怪她呢？我不会。很抱歉，我必须说，Linus 就像所有我见过的软件经理一样，是他造成了这种不利的工作环境。
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他可能会说，确保 Linux 的贡献者都表现出专业精神和相互尊重不应该是他的工作。除了代码以外，他不关心任何其他事情。
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就像 Sarah Sharp 写的那样：
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> 我对于 Linux 内核社区做出的技术努力表示最大尊重。他们在那维护一些最高标准的代码，以此来平衡并且发展一个项目。他们专注于优秀的技术，以及超过负荷的维护人员，他们有不同的文化背景和社会规范，这些意味着这些 Linux 内核维护者说话非常直率、粗鲁，或者为了完成他们的任务而不讲道理。顶尖的 Linux 内核开发者经常为了使别人改正行为而向他们大喊大叫。
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>
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> 这种事情发生在我身上，但它不是一种有效的沟通方式。
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>
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> 许多高级的 Linux 内核开发者支持那些技术上和人性上不讲道理的维护者的权利。即使他们自己是非常友好的人，他们不想看到 Linux 内核交流方式改变。
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她是对的。
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我和其他观察者不同的是，我不认为这个问题对于 Linux 或开源社区在任何方面有特殊之处。作为一个从事技术商业工作超过五年和有着 25 年技术工作经历的记者，我见多了这种不成熟的小孩子行为。
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这不是 Linus 的错误。他不是一个经理，他是一个有想象力的技术领导者。看起来真正的问题是，在软件开发领域没有人能够用一种支持的语气来对待团队和社区。
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展望未来，我希望像 Linux 基金会这样的公司和组织，能够找到一种方式去授权社区经理或其他经理来鼓励并且强制实施民主的行为。
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非常遗憾的是，我们不能够在我们这种纯技术或纯商业的领导人中找到这种管理策略。它不存在于这些人的基因中。
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--------------------------------------------------------------------------------
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via: http://www.computerworld.com/article/3004387/it-management/how-bad-a-boss-is-linus-torvalds.html
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作者：[Steven J. Vaughan-Nichols][a]
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译者：[FrankXinqi](https://github.com/FrankXinqi)
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校对：[wxy](https://github.com/wxy)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
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[a]:http://www.computerworld.com/author/Steven-J.-Vaughan_Nichols/
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[1]:http://www.computerworld.com/article/2874475/linus-torvalds-diversity-gaffe-brings-out-the-best-and-worst-of-the-open-source-world.html
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[2]:http://www.zdnet.com/article/linux-4-3-released-after-linus-torvalds-scraps-brain-damage-code/
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[3]:http://lkml.iu.edu/hypermail/linux/kernel/1510.3/02866.html
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[4]:http://sarah.thesharps.us/2015/10/05/closing-a-door/
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[5]:https://www.amazon.cn/Accidental-Empires-Cringely-Robert-X/dp/0887308554/479-5308016-9671450?ie=UTF8&qid=1447101469&ref_=sr_1_1&tag=geo-23
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@ -1,4 +1,4 @@
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基于 Python、 RabbitMQ 和 Nameko 的微服务
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用 Python、 RabbitMQ 和 Nameko 实现微服务
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==============================================
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>"微服务是一股新浪潮" - 现如今，将项目拆分成多个独立的、可扩展的服务是保障代码演变的最好选择。在 Python 的世界里，有个叫做 “Nameko” 的框架，它将微服务的实现变得简单并且强大。
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@ -8,19 +8,17 @@
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> 在最近的几年里，“微服务架构”如雨后春笋般涌现。它用于描述一种特定的软件应用设计方式，这种方式使得应用可以由多个独立部署的服务以服务套件的形式组成。 - M. Fowler
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|
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推荐各位读一下 [Fowler's posts][1] 以理解它背后的原理。
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推荐各位读一下 [Fowler 的文章][1] 以理解它背后的原理。
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#### 好吧，那它究竟意味着什么呢？
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简单来说，**微服务架构**可以将你的系统拆分成多个负责不同任务的小块儿，它们之间互不依赖，各自只提供用于通讯的通用指向。这个指向通常是已经将通讯协议和接口定义好的消息队列。
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简单来说，**微服务架构**可以将你的系统拆分成多个负责不同任务的小的（单一上下文内）功能块（responsibilities blocks），它们彼此互无感知，各自只提供用于通讯的通用指向（common point）。这个指向通常是已经将通讯协议和接口定义好的消息队列。
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#### 这里给大家提供一个真实案例
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>案例的代码可以通过github: <http://github.com/rochacbruno/nameko-example> 访问，查看 service 和 api 文件夹可以获取更多信息。
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> 案例的代码可以通过 github: <http://github.com/rochacbruno/nameko-example> 访问，查看 service 和 api 文件夹可以获取更多信息。
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想象一下，你有一个 REST API ，这个 API 有一个端点（译者注：REST 风格的 API 可以有多个端点用于处理对同一资源的不同类型的请求）用来接受数据，并且你需要将接收到的数据进行一些运算。那么相比阻塞接口调用者的请求来说，异步实现此接口是一个更好的选择。你可以先给用户返回一个 "OK - 你的请求稍后会处理" 的状态，然后在后台任务中完成运算。
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想象一下，你有一个 REST API ，这个 API 有一个端点（LCTT 译注：REST 风格的 API 可以有多个端点用于处理对同一资源的不同类型的请求）用来接受数据，并且你需要将接收到的数据进行一些运算工作。那么相比阻塞接口调用者的请求来说，异步实现此接口是一个更好的选择。你可以先给用户返回一个 "OK - 你的请求稍后会处理" 的状态，然后在后台任务中完成运算。
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|
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同样，如果你想要在不阻塞主进程的前提下，在计算完成后发送一封提醒邮件，那么将“邮件发送”委托给其他服务去做会更好一些。
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@ -30,20 +28,18 @@
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### 用代码说话：
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### 用代码说话
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让我们将系统创建起来，在实践中理解它：
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#### 环境
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我们需要的环境：
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- 运行良好的 RabbitMQ（译者注：[RabbitMQ][2]是一个流行的消息队列实现）
|
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- 运行良好的 RabbitMQ（LCTT 译注：[RabbitMQ][2] 是一个流行的消息队列实现）
|
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- 由 VirtualEnv 提供的 Services 虚拟环境
|
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- 由 VirtualEnv 提供的 API 虚拟环境
|
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|
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|
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#### Rabbit
|
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在开发环境中使用 RabbitMQ 最简单的方式就是运行其官方的 docker 容器。在你已经拥有 Docker 的情况下，运行：
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@ -56,10 +52,9 @@ docker run -d --hostname my-rabbit --name some-rabbit -p 15672:15672 -p 5672:567
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#### 服务环境
|
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现在让我们创建微服务来消费我们的任务。其中一个服务用来执行计算任务，另一个用来发送邮件。按以下步骤执行：
|
||||
现在让我们创建微服务来满足我们的任务需要。其中一个服务用来执行计算任务，另一个用来发送邮件。按以下步骤执行：
|
||||
|
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在 Shell 中创建项目的根目录
|
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|
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@ -82,7 +77,6 @@ $ source service_env/bin/activate
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(service_env)$ pip install yagmail
|
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```
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#### 服务的代码
|
||||
|
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现在我们已经准备好了 virtualenv 所提供的虚拟环境（可以想象成我们的服务是运行在一个独立服务器上的，而我们的 API 运行在另一个服务器上），接下来让我们编码，实现 nameko 的 RPC 服务。
|
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@ -135,7 +129,7 @@ class Compute(object):
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|
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现在我们已经用以上代码定义好了两个服务，下面让我们将 Nameko RPC service 运行起来。
|
||||
|
||||
>注意：我们会在控制台中启动并运行它。但在生产环境中，建议大家使用 supervisord 替代控制台命令。
|
||||
> 注意：我们会在控制台中启动并运行它。但在生产环境中，建议大家使用 supervisord 替代控制台命令。
|
||||
|
||||
在 Shell 中启动并运行服务
|
||||
|
||||
@ -149,7 +143,7 @@ Connected to amqp://guest:**@127.0.0.1:5672//
|
||||
|
||||
#### 测试
|
||||
|
||||
在另外一个 Shell 中(使用相同的虚拟环境)，用 nameko shell 进行测试：
|
||||
在另外一个 Shell 中（使用相同的虚拟环境），用 nameko shell 进行测试：
|
||||
|
||||
```
|
||||
(service_env)$ nameko shell --broker amqp://guest:guest@localhost
|
||||
@ -178,19 +172,18 @@ Broker: amqp://guest:guest@localhost
|
||||
3
|
||||
```
|
||||
|
||||
|
||||
### 在 API 中调用微服务
|
||||
|
||||
在另外一个 Shell 中（甚至可以是另外一台服务器上），准备好 API 环境。
|
||||
|
||||
用 virtualenv 工具创建并且激活一个虚拟环境(你也可以使用virtualenv-wrapper)
|
||||
用 virtualenv 工具创建并且激活一个虚拟环境（你也可以使用 virtualenv-wrapper）
|
||||
|
||||
```
|
||||
$ virtualenv api_env
|
||||
$ source api_env/bin/activate
|
||||
```
|
||||
|
||||
安装 Nameko, Flask 和 Flasgger
|
||||
安装 Nameko、 Flask 和 Flasgger
|
||||
|
||||
```
|
||||
(api_env)$ pip install nameko
|
||||
@ -269,7 +262,7 @@ app.run(debug=True)
|
||||
|
||||
|
||||
|
||||
>注意： 你可以在 shell 中查看到服务的运行日志，打印信息和错误信息。也可以访问 RabbitMQ 控制面板来查看消息在队列中的处理情况。
|
||||
> 注意： 你可以在 shell 中查看到服务的运行日志，打印信息和错误信息。也可以访问 RabbitMQ 控制面板来查看消息在队列中的处理情况。
|
||||
|
||||
Nameko 框架还为我们提供了很多高级特性，你可以从 <https://nameko.readthedocs.org/en/stable/> 获取更多的信息。
|
||||
|
||||
@ -282,7 +275,7 @@ via: http://brunorocha.org/python/microservices-with-python-rabbitmq-and-nameko.
|
||||
|
||||
作者: [Bruno Rocha][a]
|
||||
译者: [mr-ping](http://www.mr-ping.com)
|
||||
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
|
||||
|
||||
@ -0,0 +1,45 @@
|
||||
Cassandra 和 Spark 数据处理一窥
|
||||
==============================================================
|
||||
|
||||
|
||||
|
||||
Apache Cassandra 数据库近来引起了很多的兴趣，这主要源于现代云端软件对于可用性及性能方面的要求。
|
||||
|
||||
那么，Apache Cassandra 是什么？它是一种为高可用性及线性可扩展性优化的分布式的联机交易处理 (OLTP) 数据库。具体说到 Cassandra 的用途时，可以想想你希望贴近用户的系统，比如说让我们的用户进行交互的系统、需要保证实时可用的程序等等，如：产品目录，物联网，医疗系统，以及移动应用。对这些程序而言，下线时间意味着利润降低甚至导致其他更坏的结果。Netfilix 是这个在 2008 年开源的项目的早期使用者，他们对此项目的贡献以及带来的成功让这个项目名声大噪。
|
||||
|
||||
Cassandra 于2010年成为了 Apache 软件基金会的顶级项目，并从此之后就流行起来。现在，只要你有 Cassadra 的相关知识，找工作时就能轻松不少。想想看，NoSQL 语言和开源技术能达到企业级 SQL 技术的高度，真让人觉得十分疯狂而又不可思议的。这引出了一个问题。是什么让它如此的流行？
|
||||
|
||||
因为采用了[亚马逊发表的 Dynamo 论文][1]中率先提出的设计，Cassandra 有能力在大规模的硬件及网络故障时保持实时在线。由于采用了点对点模式，在没有单点故障的情况下，我们能幸免于机架故障甚至全网中断。我们能在不影响用户体验的前提下处理数据中心故障。一个能考虑到故障的分布式系统才是一个没有后顾之忧的分布式系统，因为老实说，故障是迟早会发生的。有了 Cassandra， 我们可以直面残酷的生活并将之融入数据库的结构和功能中。
|
||||
|
||||
我们能猜到你现在在想什么，“但我只有关系数据库相关背景，难道这样的转变不会很困难吗？”这问题的答案介于是和不是之间。使用 Cassandra 建立数据模型对有关系数据库背景的开发者而言是轻车熟路。我们使用表格来建立数据模型，并使用 CQL （ Cassandra 查询语言）来查询数据库。然而，与 SQL 不同的是，Cassandra 支持更加复杂的数据结构，例如嵌套和用户自定义类型。举个例子，当要储存对一个小猫照片的点赞数目时，我们可以将整个数据储存在一个包含照片本身的集合之中从而获得更快的顺序查找而不是建立一个独立的表。这样的表述在 CQL 中十分的自然。在我们照片表中，我们需要记录名字，URL以及给此照片点赞过的人。
|
||||
|
||||
|
||||
|
||||
在一个高性能系统中，毫秒级处理都能对用户体验和客户维系产生影响。昂贵的 JOIN 操作制约了我们通过增加不可预见的网络调用而扩容的能力。当我们将数据反范式化使其能通过尽可能少的请求就可获取时，我们即可从磁盘空间成本的降低中获益并获得可预期的、高性能应用。我们将反范式化同 Cassandra 一同介绍是因为它提供了很有吸引力的的折衷方案。
|
||||
|
||||
很明显，我们不会局限于对于小猫照片的点赞数量。Canssandra 是一款为高并发写入优化的方案。这使其成为需要时常吞吐数据的大数据应用的理想解决方案。实时应用和物联网方面的应用正在稳步增长，无论是需求还是市场表现，我们也会不断的利用我们收集到的数据来寻求改进技术应用的方式。
|
||||
|
||||
这就引出了我们的下一步，我们已经提到了如何以一种现代的、性价比高的方式储存数据，但我们应该如何获得更多的动力呢？具体而言，当我们收集到了所需的数据，我们应该怎样处理呢？如何才能有效的分析几百 TB 的数据呢？如何才能实时的对我们所收集到的信息进行反馈，并在几秒而不是几小时的时间利作出决策呢？Apache Spark 将给我们答案。
|
||||
|
||||
Spark 是大数据变革中的下一步。 Hadoop 和 MapReduce 都是革命性的产品，它们让大数据界获得了分析所有我们所取得的数据的机会。Spark 对性能的大幅提升及对代码复杂度的大幅降低则将大数据分析提升到了另一个高度。通过 Spark，我们能大批量的处理计算，对流处理进行快速反应，通过机器学习作出决策，并通过图遍历来理解复杂的递归关系。这并非只是为你的客户提供与快捷可靠的应用程序连接（Cassandra 已经提供了这样的功能），这更是能洞悉 Canssandra 所储存的数据，作出更加合理的商业决策并同时更好地满足客户需求。
|
||||
|
||||
你可以看看 [Spark-Cassandra Connector][2] (开源) 并动手试试。若想了解更多关于这两种技术的信息，我们强烈推荐名为 [DataStax Academy][3] 的自学课程
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/5/basics-cassandra-and-spark-data-processing
|
||||
|
||||
作者：[Jon Haddad][a],[Dani Traphagen][b]
|
||||
译者：[KevinSJ](https://github.com/KevinSJ)
|
||||
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://twitter.com/rustyrazorblade
|
||||
[b]: https://opensource.com/users/dtrapezoid
|
||||
[1]: http://www.allthingsdistributed.com/files/amazon-dynamo-sosp2007.pdf
|
||||
[2]: https://github.com/datastax/spark-cassandra-connector
|
||||
[3]: https://academy.datastax.com/
|
||||
[4]: http://conferences.oreilly.com/oscon/open-source-us/public/schedule/detail/49162
|
||||
[5]: https://twitter.com/dtrapezoid
|
||||
[6]: https://twitter.com/rustyrazorblade
|
||||
@ -0,0 +1,65 @@
|
||||
共享的未来：Pydio 与 ownCloud 的联合
|
||||
=========================================================
|
||||
|
||||
|
||||
|
||||
*图片来源 : opensource.com*
|
||||
|
||||
开源共享生态圈内容纳了许多各异的项目，它们每一个都给出了自己的解决方案，且每一个都不按套路来。有很多原因导致你选择开源的解决方案，而非 Dropbox、Google Drive、iCloud 或 OneDrive 这些商业的解决方案。这些商业的解决方案虽然能让你不必为如何管理数据担心，但也理所应当的带着种种限制，其中就包括对于原有基础结构的控制和整合不足。
|
||||
|
||||
对于用户而言仍有相当一部分可供选择的文件分享和同步的替代品，其中就包括了 Pydio 和 ownCloud。
|
||||
|
||||
### Pydio
|
||||
|
||||
Pydio （Put your data in orbit 把你的数据放上轨道） 项目由一位作曲家 Charles du Jeu 发起，起初他只是需要一种与乐队成员分享大型音频文件的方法。[Pydio][1] 是一种文件分享与同步的解决方案，综合了多存储后端，设计时还同时考虑了开发者和系统管理员两方面。在世界各地有逾百万的下载量，已被翻译成 27 种语言。
|
||||
|
||||
项目在刚开始的时候便开源了，先是在 [SourceForge][2] 上茁壮的成长，现在已在 [GitHub][3] 上安了家。
|
||||
|
||||
用户界面基于 Google 的 [Material 设计风格][4]。用户可以使用现有的传统文件基础结构或是根据预估的需求部署 Pydio，并通过 web、桌面和移动端应用随时随地地管理自己的东西。对于管理员来说，细粒度的访问权限绝对是配置访问时的利器。
|
||||
|
||||
在 [Pydio 社区][5]，你可以找到许多让你增速的资源。Pydio 网站 [对于如何为 Pydio GitHub 仓库贡献][6] 给出了明确的指导方案。[论坛][7]中也包含了开发者板块和社区。
|
||||
|
||||
### ownCloud
|
||||
|
||||
[ownCloud][8] 在世界各地拥有逾 8 百万的用户，它是一个开源、自行管理的文件同步共享技术。同步客户端支持所有主流平台并支持 WebDAV 通过 web 界面实现。ownCloud 拥有简单的使用界面，强大的管理工具，和大规模的共享及协作功能——以满足用户管理数据时的需求。
|
||||
|
||||
ownCloud 的开放式架构是通过 API 和为应用提供平台来实现可扩展性的。迄今已有逾 300 款应用，功能包括处理像日历、联系人、邮件、音乐、密码、笔记等诸多数据类型。ownCloud 由一个数百位贡献者的国际化的社区开发，安全，并且能做到为小到一个树莓派大到好几百万用户的 PB 级存储集群量身定制。
|
||||
|
||||
### 联合共享 （Federated sharing）
|
||||
|
||||
文件共享开始转向团队合作时代，而标准化为合作提供了坚实的土壤。
|
||||
|
||||
联合共享（Federated sharing）——一个由 [OpenCloudMesh][9] 项目提供的新的开放标准，就是在这个方向迈出的一步。先不说别的，在支持该标准的服务器之间分享文件和文件夹，比如说 Pydio 和 ownCloud。
|
||||
|
||||
ownCloud 7 率先引入该标准，这种服务器到服务器的分享方式可以让你挂载远程服务器上共享的文件，实际上就是创建你自己的云上之云。你可以直接为其它支持联合共享的服务器上的用户创建共享链接。
|
||||
|
||||
实现这个新的 API 允许存储解决方案之间更深层次的集成，同时保留了原有平台的安全，控制和特性。
|
||||
|
||||
“交换和共享文件是当下和未来不可或缺的东西。”ownCloud 的创始人 Frank Karlitschek 说道：“正因如此，采用联合和分布的方式而非集中的数据孤岛就显得至关重要。联合共享的设计初衷便是在保证安全和用户隐私的同时追求分享的无缝、至简之道。”
|
||||
|
||||
### 下一步是什么呢？
|
||||
|
||||
正如 OpenCloudMesh 做的那样，将会通过像 Pydio 和 ownCloud 这样的机构和公司，合作推广这一文件共享的新开放标准。ownCloud 9 已经引入联合的服务器之间交换用户列表的功能，让你的用户们在你的服务器上享有和你同样的无缝体验。将来，一个中央地址簿服务（联合的）集合，用以检索其他联合云 ID 的构想可能会把云间合作推向一个新的高度。
|
||||
|
||||
这一举措无疑有助于日益开放的技术社区中的那些成员方便地讨论，开发，并推动“OCM 分享 API”作为一个厂商中立协议。所有领导 OCM 项目的合作伙伴都全心致力于开放 API 的设计原则，并欢迎其他开源的文件分享和同步社区参与并加入其中。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/business/16/5/sharing-files-pydio-owncloud
|
||||
|
||||
作者：[ben van 't ende][a]
|
||||
译者：[martin2011qi](https://github.com/martin2011qi)
|
||||
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/benvantende
|
||||
[1]: https://pydio.com/
|
||||
[2]: https://sourceforge.net/projects/ajaxplorer/
|
||||
[3]: https://github.com/pydio/
|
||||
[4]: https://www.google.com/design/spec/material-design/introduction.html
|
||||
[5]: https://pydio.com/en/community
|
||||
[6]: https://pydio.com/en/community/contribute
|
||||
[7]: https://pydio.com/forum/f
|
||||
[8]: https://owncloud.org/
|
||||
[9]: https://wiki.geant.org/display/OCM/Open+Cloud+Mesh
|
||||
@ -0,0 +1,64 @@
|
||||
教你用 google-drive-ocamlfuse 在 Linux 上挂载 Google Drive
|
||||
=====================
|
||||
|
||||
> 如果你在找一个方便的方式在 Linux 机器上挂载你的 Google Drive 文件夹， Jack Wallen 将教你怎么使用 google-drive-ocamlfuse 来挂载 Google Drive。
|
||||
|
||||
|
||||
|
||||
*图片来源: Jack Wallen*
|
||||
|
||||
Google 还没有发行 Linux 版本的 Google Drive 应用，尽管现在有很多方法从 Linux 中访问你的 Drive 文件。
|
||||
|
||||
如果你喜欢界面化的工具，你可以选择 Insync。如果你喜欢用命令行，有很多像 Grive2 这样的工具，和更容易使用的以 Ocaml 语言编写的基于 FUSE 的文件系统。我将会用后面这种方式演示如何在 Linux 桌面上挂载你的 Google Drive。尽管这是通过命令行完成的，但是它的用法会简单到让你吃惊。它太简单了以至于谁都能做到。
|
||||
|
||||
这个系统的特点：
|
||||
|
||||
- 对普通文件/文件夹有完全的读写权限
|
||||
- 对于 Google Docs，sheets，slides 这三个应用只读
|
||||
- 能够访问 Drive 回收站（.trash）
|
||||
- 处理重复文件功能
|
||||
- 支持多个帐号
|
||||
|
||||
让我们接下来完成 google-drive-ocamlfuse 在 Ubuntu 16.04 桌面的安装，然后你就能够访问云盘上的文件了。
|
||||
|
||||
### 安装
|
||||
|
||||
1. 打开终端。
|
||||
2. 用 `sudo add-apt-repository ppa:alessandro-strada/ppa` 命令添加必要的 PPA
|
||||
3. 出现提示的时候，输入你的 root 密码并按下回车。
|
||||
4. 用 `sudo apt-get update` 命令更新应用。
|
||||
5. 输入 `sudo apt-get install google-drive-ocamlfuse` 命令安装软件。
|
||||
|
||||
### 授权
|
||||
|
||||
接下来就是授权 google-drive-ocamlfuse，让它有权限访问你的 Google 账户。先回到终端窗口敲下命令 `google-drive-ocamlfuse`，这个命令将会打开一个浏览器窗口，它会提示你登陆你的 Google 帐号或者如果你已经登陆了 Google 帐号，它会询问是否允许 google-drive-ocamlfuse 访问 Google 账户。如果你还没有登录，先登录然后点击“允许”。接下来的窗口（在 Ubuntu 16.04 桌面上会出现，但不会出现在 Elementary OS Freya 桌面上）将会询问你是否授给 gdfuse 和 OAuth2 Endpoint 访问你的 Google 账户的权限，再次点击“允许”。然后出现的窗口就会告诉你等待授权令牌下载完成，这个时候就能最小化浏览器了。当你的终端提示如下图一样的内容，你就能知道令牌下载完了，并且你已经可以挂载 Google Drive 了。
|
||||
|
||||
|
||||
|
||||
*应用已经得到授权，你可以进行后面的工作。*
|
||||
|
||||
### 挂载 Google Drive
|
||||
|
||||
在挂载 Google Drive 之前，你得先创建一个文件夹，作为挂载点。在终端里，敲下`mkdir ~/google-drive`命令在你的家目录下创建一个新的文件夹。最后敲下命令`google-drive-ocamlfuse ~/google-drive`将你的 Google Drive 挂载到 google-drive 文件夹中。
|
||||
|
||||
这时你可以查看本地 google-drive 文件夹中包含的 Google Drive 文件/文件夹。你可以把 Google Drive 当作本地文件系统来进行工作。
|
||||
|
||||
当你想卸载 google-drive 文件夹，输入命令 `fusermount -u ~/google-drive`。
|
||||
|
||||
### 没有 GUI，但它特别好用
|
||||
|
||||
我发现这个特别的系统非常容易使用，在同步 Google Drive 时它出奇的快，并且这可以作为一种本地备份你的 Google Drive 账户的巧妙方式。（LCTT 译注：然而首先你得能使用……）
|
||||
|
||||
试试 google-drive-ocamlfuse，看看你能用它做出什么有趣的事。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.techrepublic.com/article/how-to-mount-your-google-drive-on-linux-with-google-drive-ocamlfuse/
|
||||
|
||||
作者：[Jack Wallen][a]
|
||||
译者：[GitFuture](https://github.com/GitFuture)
|
||||
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]: http://www.techrepublic.com/search/?a=jack+wallen
|
||||
@ -1,17 +1,17 @@
|
||||
在 Ubuntu 16.04 上安装使用 VBoxManage 以及 VBoxManage 命令行选项的用法
|
||||
在 Linux 上安装使用 VirtualBox 的命令行管理界面 VBoxManage
|
||||
=================
|
||||
|
||||
VirtualBox 拥有一套命令行工具，然后你可以使用 VirtualBox 的命令行界面 (CLI) 对远端无界面的服务器上的虚拟机进行管理操作。在这篇教程中，你将会学到如何在没有 GUI 的情况下使用 VBoxManage 创建、启动一个虚拟机。VBoxManage 是 VirtualBox 的命令行界面，你可以在你的主机操作系统的命令行中来用它实现对 VirtualBox 的所有操作。VBoxManage 拥有图形化用户界面所支持的全部功能，而且它支持的功能远不止这些。它提供虚拟引擎的所有功能，甚至包含 GUI 还不能实现的那些功能。如果你想尝试不同的用户界面而不仅仅是 GUI，或者更改虚拟机更多高级和实验性的配置，那么你就需要用到命令行。
|
||||
VirtualBox 拥有一套命令行工具，你可以使用 VirtualBox 的命令行界面 (CLI) 对远程无界面的服务器上的虚拟机进行管理操作。在这篇教程中，你将会学到如何在没有 GUI 的情况下使用 VBoxManage 创建、启动一个虚拟机。VBoxManage 是 VirtualBox 的命令行界面，你可以在你的主机操作系统的命令行中用它来实现对 VirtualBox 的所有操作。VBoxManage 拥有图形化用户界面所支持的全部功能，而且它支持的功能远不止这些。它提供虚拟引擎的所有功能，甚至包含 GUI 还不能实现的那些功能。如果你想尝试下不同的用户界面而不仅仅是 GUI，或者更改虚拟机更多高级和实验性的配置，那么你就需要用到命令行。
|
||||
|
||||
当你想要在 VirtualBox 上创建或运行虚拟机时，你会发现 VBoxManage 非常有用，你只需要使用远程主机的终端就够了。这对于服务器来说是一种常见的情形，因为在服务器上需要进行虚拟机的远程操作。
|
||||
当你想要在 VirtualBox 上创建或运行虚拟机时，你会发现 VBoxManage 非常有用，你只需要使用远程主机的终端就够了。这对于需要远程管理虚拟机的服务器来说是一种常见的情形。
|
||||
|
||||
### 准备工作
|
||||
|
||||
在开始使用 VBoxManage 的命令行工具前，确保在运行着 Ubuntu 16.04 的服务器上，你拥有超级用户的权限或者你能够使用 sudo 命令，而且你已经在服务器上安装了 Oracle Virtual Box。 然后你需要安装 VirtualBox 扩展包，这是运行远程桌面环境，访问无界面启动虚拟机所必须的。（headless的翻译拿不准，翻译为无界面启动）
|
||||
在开始使用 VBoxManage 的命令行工具前，确保在运行着 Ubuntu 16.04 的服务器上，你拥有超级用户的权限或者你能够使用 sudo 命令，而且你已经在服务器上安装了 Oracle Virtual Box。 然后你需要安装 VirtualBox 扩展包，这是运行 VRDE 远程桌面环境，访问无界面虚拟机所必须的。
|
||||
|
||||
### 安装 VBoxManage
|
||||
|
||||
通过 [Virtual Box Download Page][1] 这个链接，你能够获取你所需要的软件扩展包的最新版本，扩展包的版本和你安装的 VirtualBox 版本需要一致！
|
||||
通过 [Virtual Box 下载页][1] 这个链接，你能够获取你所需要的软件扩展包的最新版本，扩展包的版本和你安装的 VirtualBox 版本需要一致！
|
||||
|
||||
|
||||
|
||||
@ -71,11 +71,11 @@ $ VBoxManage modifyvm Ubuntu10.10 --memory 512
|
||||
$ VBoxManage storagectl Ubuntu16.04 --name IDE --add ide --controller PIIX4 --bootable on
|
||||
```
|
||||
|
||||
这里的 “storagect1” 是给虚拟机创建存储控制器的，“--name” 指定了虚拟机里需要创建、更改或者移除的存储控制器的名称。“--add” 选项指明系统总线类型，可选的选项有 ide / sata / scsi / floppy，存储控制器必须要连接到系统总线。“--controller” 选择主板的类型，主板需要根据需要的存储控制器选择，可选的选项有 LsiLogic / LSILogicSAS / BusLogic / IntelAhci / PIIX3 / PIIX4 / ICH6 / I82078。最后的 “--bootable” 表示控制器是否可以引导。
|
||||
这里的 “storagect1” 是给虚拟机创建存储控制器的，“--name” 指定了虚拟机里需要创建、更改或者移除的存储控制器的名称。“--add” 选项指明存储控制器所需要连接到的系统总线类型，可选的选项有 ide / sata / scsi / floppy。“--controller” 选择主板的类型，主板需要根据需要的存储控制器选择，可选的选项有 LsiLogic / LSILogicSAS / BusLogic / IntelAhci / PIIX3 / PIIX4 / ICH6 / I82078。最后的 “--bootable” 表示控制器是否可以引导系统。
|
||||
|
||||
上面的命令创建了叫做 IDE 的存储控制器。然后虚拟设备就能通过 “storageattach” 命令连接到控制器。
|
||||
上面的命令创建了叫做 IDE 的存储控制器。之后虚拟介质就能通过 “storageattach” 命令连接到该控制器。
|
||||
|
||||
然后运行下面这个命令来创建一个叫做 SATA 的存储控制器，它将会连接到硬盘镜像上。
|
||||
然后运行下面这个命令来创建一个叫做 SATA 的存储控制器，它将会连接到之后的硬盘镜像上。
|
||||
|
||||
```
|
||||
$ VBoxManage storagectl Ubuntu16.04 --name SATA --add sata --controller IntelAhci --bootable on
|
||||
@ -87,7 +87,7 @@ $ VBoxManage storagectl Ubuntu16.04 --name SATA --add sata --controller IntelAhc
|
||||
$ VBoxManage storageattach Ubuntu16.04 --storagectl SATA --port 0 --device 0 --type hdd --medium "your_iso_filepath"
|
||||
```
|
||||
|
||||
用媒体把 SATA 存储控制器连接到 Ubuntu16.04 虚拟机中，也就是之前创建的虚拟硬盘镜像里。
|
||||
这将把 SATA 存储控制器及介质（比如之前创建的虚拟磁盘镜像）连接到 Ubuntu16.04 虚拟机中。
|
||||
|
||||
运行下面的命令添加像网络连接，音频之类的功能。
|
||||
|
||||
@ -120,9 +120,9 @@ $VBoxManage controlvm
|
||||
|
||||
|
||||
|
||||
完结！
|
||||
###完结
|
||||
|
||||
从这篇文章中，我们了解了 Oracle Virtual Box 中一个十分实用的工具，就是 VBoxManage，包含了 VBoxManage 的安装和在 Ubuntu 16.04 系统上的使用。文章包含详细的教程， 通过 VBoxManage 中实用的命令来创建和管理虚拟机。希望这篇文章对你有帮助，另外别忘了分享你的评论或者建议。
|
||||
从这篇文章中，我们了解了 Oracle Virtual Box 中一个十分实用的工具 VBoxManage，文章包含了 VBoxManage 的安装和在 Ubuntu 16.04 系统上的使用，包括通过 VBoxManage 中实用的命令来创建和管理虚拟机。希望这篇文章对你有帮助，另外别忘了分享你的评论或者建议。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -130,7 +130,7 @@ via: http://linuxpitstop.com/install-and-use-command-line-tool-vboxmanage-on-ubu
|
||||
|
||||
作者：[Kashif][a]
|
||||
译者：[GitFuture](https://github.com/GitFuture)
|
||||
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
|
||||
|
||||
227
published/20160620 Detecting cats in images with OpenCV.md
Normal file
227
published/20160620 Detecting cats in images with OpenCV.md
Normal file
@ -0,0 +1,227 @@
|
||||
使用 OpenCV 识别图片中的猫咪
|
||||
=======================================
|
||||
|
||||
|
||||
|
||||
你知道 OpenCV 可以识别在图片中小猫的脸吗？而且是拿来就能用，不需要其它的库之类的。
|
||||
|
||||
之前我也不知道。
|
||||
|
||||
但是在 [Kendrick Tan 曝出这个功能][1]后，我需要亲自体验一下……去看看到 OpenCV 是如何在我没有察觉到的情况下，将这一个功能添加进了他的软件库（就像一只悄悄溜进空盒子的猫咪一样，等待别人发觉）。
|
||||
|
||||
下面，我将会展示如何使用 OpenCV 的猫咪检测器在图片中识别小猫的脸。同样的，该技术也可以用在视频流中。
|
||||
|
||||
### 使用 OpenCV 在图片中检测猫咪
|
||||
|
||||
如果你查找过 [OpenCV 的代码仓库][3]，尤其是在 [haarcascades 目录][4]里（OpenCV 在这里保存处理它预先训练好的 Haar 分类器，以检测各种物体、身体部位等）， 你会看到这两个文件:
|
||||
|
||||
- haarcascade_frontalcatface.xml
|
||||
- haarcascade\_frontalcatface\_extended.xml
|
||||
|
||||
这两个 Haar Cascade 文件都将被用来在图片中检测小猫的脸。实际上，我使用了相同的 cascades 分类器来生成这篇博文顶端的图片。
|
||||
|
||||
在做了一些调查工作之后，我发现这些 cascades 分类器是由鼎鼎大名的 [Joseph Howse][5]训练和贡献给 OpenCV 仓库的，他写了很多很棒的教程和书籍，在计算机视觉领域有着很高的声望。
|
||||
|
||||
下面，我将会展示给你如何使用 Howse 的 Haar cascades 分类器来检测图片中的小猫。
|
||||
|
||||
### 猫咪检测代码
|
||||
|
||||
让我们开始使用 OpenCV 来检测图片中的猫咪。新建一个叫 cat_detector.py 的文件，并且输入如下的代码:
|
||||
|
||||
```
|
||||
# import the necessary packages
|
||||
import argparse
|
||||
import cv2
|
||||
|
||||
# construct the argument parse and parse the arguments
|
||||
ap = argparse.ArgumentParser()
|
||||
ap.add_argument("-i", "--image", required=True,
|
||||
help="path to the input image")
|
||||
ap.add_argument("-c", "--cascade",
|
||||
default="haarcascade_frontalcatface.xml",
|
||||
help="path to cat detector haar cascade")
|
||||
args = vars(ap.parse_args())
|
||||
```
|
||||
|
||||
第 2 和第 3 行主要是导入了必要的 python 包。6-12 行用于解析我们的命令行参数。我们仅要求一个必需的参数 `--image` ，它是我们要使用 OpenCV 检测猫咪的图片。
|
||||
|
||||
我们也可以（可选的）通过 `--cascade` 参数指定我们的 Haar cascade 分类器的路径。默认使用 `haarcascades_frontalcatface.xml`，假定这个文件和你的 `cat_detector.py` 在同一目录下。
|
||||
|
||||
注意：我已经打包了猫咪的检测代码，还有在这个教程里的样本图片。你可以在博文原文的 “下载” 部分下载到。如果你是刚刚接触 Python+OpenCV（或者 Haar cascade），我建议你下载这个 zip 压缩包，这个会方便你跟着教程学习。
|
||||
|
||||
接下来，就是检测猫的时刻了：
|
||||
|
||||
```
|
||||
# load the input image and convert it to grayscale
|
||||
image = cv2.imread(args["image"])
|
||||
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
|
||||
|
||||
# load the cat detector Haar cascade, then detect cat faces
|
||||
# in the input image
|
||||
detector = cv2.CascadeClassifier(args["cascade"])
|
||||
rects = detector.detectMultiScale(gray, scaleFactor=1.3,
|
||||
minNeighbors=10, minSize=(75, 75))
|
||||
```
|
||||
|
||||
在 15、16 行，我们从硬盘上读取了图片，并且进行灰度化（这是一个在将图片传给 Haar cascade 分类器之前的常用的图片预处理步骤，尽管不是必须的）
|
||||
|
||||
20 行，从硬盘加载 Haar casacade 分类器，即猫咪检测器，并且实例化 `cv2.CascadeClassifier` 对象。
|
||||
|
||||
在 21、22 行通过调用 `detector` 的 `detectMultiScale` 方法使用 OpenCV 完成猫脸检测。我们给 `detectMultiScale` 方法传递了四个参数。包括：
|
||||
|
||||
1. 图片 `gray`，我们要在该图片中检测猫脸。
|
||||
2. 检测猫脸时的[图片金字塔][6] 的检测粒度 `scaleFactor` 。更大的粒度将会加快检测的速度，但是会对检测准确性（ true-positive）产生影响。相反的，一个更小的粒度将会影响检测的时间，但是会增加准确性（ true-positive）。但是，细粒度也会增加误报率（false-positive）。你可以看这篇博文的“ Haar cascades 注意事项”部分来获得更多的信息。
|
||||
3. `minNeighbors` 参数控制了检定框的最少数量，即在给定区域内被判断为猫脸的最少数量。这个参数可以很好的排除误报（false-positive）结果。
|
||||
4. 最后，`minSize` 参数不言自明。这个值描述每个检定框的最小宽高尺寸（单位是像素），这个例子中就是 75\*75
|
||||
|
||||
`detectMultiScale` 函数会返回 `rects`，这是一个 4 元组列表。这些元组包含了每个检测到的猫脸的 (x,y) 坐标值，还有宽度、高度。
|
||||
|
||||
最后，让我们在图片上画下这些矩形来标识猫脸：
|
||||
|
||||
```
|
||||
# loop over the cat faces and draw a rectangle surrounding each
|
||||
for (i, (x, y, w, h)) in enumerate(rects):
|
||||
cv2.rectangle(image, (x, y), (x + w, y + h), (0, 0, 255), 2)
|
||||
cv2.putText(image, "Cat #{}".format(i + 1), (x, y - 10),
|
||||
cv2.FONT_HERSHEY_SIMPLEX, 0.55, (0, 0, 255), 2)
|
||||
|
||||
# show the detected cat faces
|
||||
cv2.imshow("Cat Faces", image)
|
||||
cv2.waitKey(0)
|
||||
```
|
||||
|
||||
给我们这些框（比如，rects）的数据，我们在 25 行依次遍历它。
|
||||
|
||||
在 26 行，我们在每张猫脸的周围画上一个矩形。27、28 行展示了一个整数，即图片中猫咪的数量。
|
||||
|
||||
最后，31，32 行在屏幕上展示了输出的图片。
|
||||
|
||||
### 猫咪检测结果
|
||||
|
||||
为了测试我们的 OpenCV 猫咪检测器，可以在原文的最后，下载教程的源码。
|
||||
|
||||
然后，在你解压缩之后，你将会得到如下的三个文件/目录:
|
||||
|
||||
1. cat_detector.py：我们的主程序
|
||||
2. haarcascade_frontalcatface.xml： 猫咪检测器 Haar cascade
|
||||
3. images：我们将会使用的检测图片目录。
|
||||
|
||||
到这一步，执行以下的命令：
|
||||
|
||||
```
|
||||
$ python cat_detector.py --image images/cat_01.jpg
|
||||
```
|
||||
|
||||
|
||||
|
||||
*图 1. 在图片中检测猫脸，甚至是猫咪部分被遮挡了。*
|
||||
|
||||
注意，我们已经可以检测猫脸了，即使它的其余部分是被遮挡的。
|
||||
|
||||
试下另外的一张图片:
|
||||
|
||||
```
|
||||
python cat_detector.py --image images/cat_02.jpg
|
||||
```
|
||||
|
||||
|
||||
|
||||
*图 2. 使用 OpenCV 检测猫脸的第二个例子，这次猫脸稍有不同。*
|
||||
|
||||
这次的猫脸和第一次的明显不同，因为它正在发出“喵呜”叫声的当中。这种情况下，我们依旧能检测到正确的猫脸。
|
||||
|
||||
在下面这张图片的结果也是正确的：
|
||||
|
||||
```
|
||||
$ python cat_detector.py --image images/cat_03.jpg
|
||||
```
|
||||
|
||||
|
||||
|
||||
*图 3. 使用 OpenCV 和 python 检测猫脸*
|
||||
|
||||
我们最后的一个样例就是在一张图中检测多张猫脸:
|
||||
|
||||
```
|
||||
$ python cat_detector.py --image images/cat_04.jpg
|
||||
```
|
||||
|
||||
|
||||
|
||||
*图 4. 在同一张图片中使用 OpenCV 检测多只猫*
|
||||
|
||||
注意，Haar cascade 返回的检定框不一定是以你预期的顺序。这种情况下，中间的那只猫会被标记成第三只。你可以通过判断他们的 (x, y) 坐标来自己排序这些检定框。
|
||||
|
||||
#### 关于精度的说明
|
||||
|
||||
在这个 xml 文件中的注释非常重要，Joseph Hower 提到了这个猫脸检测器有可能会将人脸识别成猫脸。
|
||||
|
||||
这种情况下，他推荐使用两种检测器（人脸 & 猫脸），然后将出现在人脸识别结果中的结果剔除掉。
|
||||
|
||||
#### Haar cascades 注意事项
|
||||
|
||||
这个方法首先出现在 Paul Viola 和 Michael Jones 2001 年出版的 [Rapid Object Detection using a Boosted Cascade of Simple Features][7] 论文中。现在它已经成为了计算机识别领域引用最多的论文之一。
|
||||
|
||||
这个算法能够识别图片中的对象，无论它们的位置和比例。而且最令人感兴趣的或许是它能在现有的硬件条件下实现实时检测。
|
||||
|
||||
在他们的论文中，Viola 和 Jones 关注在训练人脸检测器；但是，这个框架也能用来检测各类事物，如汽车、香蕉、路标等等。
|
||||
|
||||
#### 问题是？
|
||||
|
||||
Haar cascades 最大的问题就是如何确定 `detectMultiScale` 方法的参数正确。特别是 `scaleFactor` 和 `minNeighbors` 参数。你很容易陷入一张一张图片调参数的坑，这个就是该对象检测器很难被实用化的原因。
|
||||
|
||||
这个 `scaleFactor` 变量控制了用来检测对象的图片的各种比例的[图像金字塔][8]。如果 `scaleFactor` 参数过大，你就只需要检测图像金字塔中较少的层，这可能会导致你丢失一些在图像金字塔层之间缩放时少了的对象。
|
||||
|
||||
换句话说，如果 `scaleFactor` 参数过低，你会检测过多的金字塔图层。这虽然可以能帮助你检测到更多的对象。但是他会造成计算速度的降低，还会**明显**提高误报率。Haar cascades 分类器就是这样。
|
||||
|
||||
为了避免这个，我们通常使用 [Histogram of Oriented Gradients + 线性 SVM 检测][9] 替代。
|
||||
|
||||
上述的 HOG + 线性 SVM 框架的参数更容易调优。而且更好的误报率也更低，但是唯一不好的地方是无法实时运算。
|
||||
|
||||
### 对对象识别感兴趣？并且希望了解更多？
|
||||
|
||||
|
||||
|
||||
*图 5. 在 PyImageSearch Gurus 课程中学习如何构建自定义的对象识别器。*
|
||||
|
||||
如果你对学习如何训练自己的自定义对象识别器感兴趣，请务必要去了解下 PyImageSearch Gurus 课程。
|
||||
|
||||
在这个课程中，我提供了 15 节课，覆盖了超过 168 页的教程，来教你如何从 0 开始构建自定义的对象识别器。你会掌握如何应用 HOG + 线性 SVM 框架来构建自己的对象识别器来识别路标、面孔、汽车（以及附近的其它东西）。
|
||||
|
||||
要学习 PyImageSearch Gurus 课程（有 10 节示例免费课程），点此：https://www.pyimagesearch.com/pyimagesearch-gurus/?src=post-cat-detection
|
||||
|
||||
### 总结
|
||||
|
||||
在这篇博文里，我们学习了如何使用 OpenCV 默认就有的 Haar cascades 分类器来识别图片中的猫脸。这些 Haar casacades 是由 [Joseph Howse][9] 训练兵贡献给 OpenCV 项目的。我是在 Kendrick Tan 的[这篇文章][10]中开始注意到这个。
|
||||
|
||||
尽管 Haar cascades 相当有用，但是我们也经常用 HOG + 线性 SVM 替代。因为后者相对而言更容易使用，并且可以有效地降低误报率。
|
||||
|
||||
我也会[在 PyImageSearch Gurus 课程中][11]详细的讲述如何构建定制的 HOG + 线性 SVM 对象识别器，来识别包括汽车、路标在内的各种事物。
|
||||
|
||||
不管怎样，我希望你喜欢这篇博文。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.pyimagesearch.com/2016/06/20/detecting-cats-in-images-with-opencv/
|
||||
|
||||
作者：[Adrian Rosebrock][a]
|
||||
译者：[MikeCoder](https://github.com/MikeCoder)
|
||||
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]: http://www.pyimagesearch.com/author/adrian/
|
||||
[1]: http://kendricktan.github.io/find-cats-in-photos-using-computer-vision.html
|
||||
[2]: http://www.pyimagesearch.com/2016/06/20/detecting-cats-in-images-with-opencv/#
|
||||
[3]: https://github.com/Itseez/opencv
|
||||
[4]: https://github.com/Itseez/opencv/tree/master/data/haarcascades
|
||||
[5]: http://nummist.com/
|
||||
[6]: http://www.pyimagesearch.com/2015/03/16/image-pyramids-with-python-and-opencv/
|
||||
[7]: https://www.cs.cmu.edu/~efros/courses/LBMV07/Papers/viola-cvpr-01.pdf
|
||||
[8]: http://www.pyimagesearch.com/2015/03/16/image-pyramids-with-python-and-opencv/
|
||||
[9]: http://www.pyimagesearch.com/2014/11/10/histogram-oriented-gradients-object-detection/
|
||||
[10]: http://kendricktan.github.io/find-cats-in-photos-using-computer-vision.html
|
||||
[11]: https://www.pyimagesearch.com/pyimagesearch-gurus/
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,105 @@
|
||||
Fedora 中的容器技术：systemd-nspawn
|
||||
===
|
||||
|
||||
欢迎来到“Fedora 中的容器技术”系列！本文是该系列文章中的第一篇，它将说明你可以怎样使用 Fedora 中各种可用的容器技术。本文将学习 `systemd-nspawn` 的相关知识。
|
||||
|
||||
### 容器是什么？
|
||||
|
||||
一个容器就是一个用户空间实例，它能够在与托管容器的系统（叫做宿主系统）相隔离的环境中运行一个程序或者一个操作系统。这和 `chroot` 或 [虚拟机][1] 的思想非常类似。运行在容器中的进程是由与宿主操作系统相同的内核来管理的，但它们是与宿主文件系统以及其它进程隔离开的。
|
||||
|
||||
### 什么是 systemd-nspawn？
|
||||
|
||||
systemd 项目认为应当将容器技术变成桌面的基础部分，并且应当和用户的其余系统集成在一起。为此，systemd 提供了 `systemd-nspawn`，这款工具能够使用多种 Linux 技术创建容器。它也提供了一些容器管理工具。
|
||||
|
||||
`systemd-nspawn` 和 `chroot` 在许多方面都是类似的，但是前者更加强大。它虚拟化了文件系统、进程树以及客户系统中的进程间通信。它的吸引力在于它提供了很多用于管理容器的工具，例如用来管理容器的 `machinectl`。由 `systemd-nspawn` 运行的容器将会与 systemd 组件一同运行在宿主系统上。举例来说，一个容器的日志可以输出到宿主系统的日志中。
|
||||
|
||||
在 Fedora 24 上，`systemd-nspawn` 已经从 systemd 软件包分离出来了，所以你需要安装 `systemd-container` 软件包。一如往常，你可以使用 `dnf install systemd-container` 进行安装。
|
||||
|
||||
### 创建容器
|
||||
|
||||
使用 `systemd-nspawn` 创建一个容器是很容易的。假设你有一个专门为 Debian 创造的应用，并且无法在其它发行版中正常运行。那并不是一个问题，我们可以创造一个容器！为了设置容器使用最新版本的 Debian（现在是 Jessie），你需要挑选一个目录来放置你的系统。我暂时将使用目录 `~/DebianJessie`。
|
||||
|
||||
一旦你创建完目录，你需要运行 `debootstrap`，你可以从 Fedora 仓库中安装它。对于 Debian Jessie，你运行下面的命令来初始化一个 Debian 文件系统。
|
||||
|
||||
```
|
||||
$ debootstrap --arch=amd64 stable ~/DebianJessie
|
||||
```
|
||||
|
||||
以上默认你的架构是 x86_64。如果不是的话，你必须将架构的名称改为 `amd64`。你可以使用 `uname -m` 得知你的机器架构。
|
||||
|
||||
一旦设置好你的根目录，你就可以使用下面的命令来启动你的容器。
|
||||
|
||||
```
|
||||
$ systemd-nspawn -bD ~/DebianJessie
|
||||
```
|
||||
|
||||
容器将会在数秒后准备好并运行，当你试图登录时就会注意到：你无法使用你的系统上任何账户。这是因为 `systemd-nspawn` 虚拟化了用户。修复的方法很简单：将之前的命令中的 `-b` 移除即可。你将直接进入容器的 root 用户的 shell。此时，你只能使用 `passwd` 命令为 root 设置密码，或者使用 `adduser` 命令添加一个新用户。一旦设置好密码或添加好用户，你就可以把 `-b` 标志添加回去然后继续了。你会进入到熟悉的登录控制台，然后你使用设置好的认证信息登录进去。
|
||||
|
||||
以上对于任意你想在容器中运行的发行版都适用，但前提是你需要使用正确的包管理器创建系统。对于 Fedora，你应使用 DNF 而非 `debootstrap`。想要设置一个最小化的 Fedora 系统，你可以运行下面的命令，要将“/absolute/path/”替换成任何你希望容器存放的位置。
|
||||
|
||||
```
|
||||
$ sudo dnf --releasever=24 --installroot=/absolute/path/ install systemd passwd dnf fedora-release
|
||||
```
|
||||
|
||||
|
||||
|
||||
### 设置网络
|
||||
|
||||
如果你尝试启动一个服务，但它绑定了你宿主机正在使用的端口，你将会注意到这个问题：你的容器正在使用和宿主机相同的网络接口。幸运的是，`systemd-nspawn` 提供了几种可以将网络从宿主机分开的方法。
|
||||
|
||||
#### 本地网络
|
||||
|
||||
第一种方法是使用 `--private-network` 标志，它默认仅创建一个回环设备。这对于你不需要使用网络的环境是非常理想的，例如构建系统和其它持续集成系统。
|
||||
|
||||
#### 多个网络接口
|
||||
|
||||
如果你有多个网络接口设备，你可以使用 `--network-interface` 标志给容器分配一个接口。想要给我的容器分配 `eno1`，我会添加选项 `--network-interface=eno1`。当某个接口分配给一个容器后，宿主机就不能同时使用那个接口了。只有当容器彻底关闭后，宿主机才可以使用那个接口。
|
||||
|
||||
#### 共享网络接口
|
||||
|
||||
对于我们中那些并没有额外的网络设备的人来说，还有其它方法可以访问容器。一种就是使用 `--port` 选项。这会将容器中的一个端口定向到宿主机。使用格式是 `协议:宿主机端口:容器端口`，这里的协议可以是 `tcp` 或者 `udp`，`宿主机端口` 是宿主机的一个合法端口，`容器端口` 则是容器中的一个合法端口。你可以省略协议，只指定 `宿主机端口:容器端口`。我通常的用法类似 `--port=2222:22`。
|
||||
|
||||
你可以使用 `--network-veth` 启用完全的、仅宿主机模式的网络，这会在宿主机和容器之间创建一个虚拟的网络接口。你也可以使用 `--network-bridge` 桥接二者的连接。
|
||||
|
||||
### 使用 systemd 组件
|
||||
|
||||
如果你容器中的系统含有 D-Bus，你可以使用 systemd 提供的实用工具来控制并监视你的容器。基础安装的 Debian 并不包含 `dbus`。如果你想在 Debian Jessie 中使用 `dbus`，你需要运行命令 `apt install dbus`。
|
||||
|
||||
#### machinectl
|
||||
|
||||
为了能够轻松地管理容器，systemd 提供了 `machinectl` 实用工具。使用 `machinectl`，你可以使用 `machinectl login name` 登录到一个容器中、使用 `machinectl status name`检查状态、使用 `machinectl reboot name` 启动容器或者使用 `machinectl poweroff name` 关闭容器。
|
||||
|
||||
### 其它 systemd 命令
|
||||
|
||||
多数 systemd 命令，例如 `journalctl`, `systemd-analyze` 和 `systemctl`，都支持使用 `--machine` 选项来指定容器。例如，如果你想查看一个名为 “foobar” 的容器的日志，你可以使用 `journalctl --machine=foobar`。你也可以使用 `systemctl --machine=foobar status service` 来查看运行在这个容器中的服务状态。
|
||||
|
||||
|
||||
|
||||
### 和 SELinux 一起工作
|
||||
|
||||
如果你要使用 SELinux 强制模式（Fedora 默认模式），你需要为你的容器设置 SELinux 环境。想要那样的话，你需要在宿主系统上运行下面两行命令。
|
||||
|
||||
```
|
||||
$ semanage fcontext -a -t svirt_sandbox_file_t "/path/to/container(/.*)?"
|
||||
$ restorecon -R /path/to/container/
|
||||
```
|
||||
|
||||
确保使用你的容器路径替换 “/path/to/container”。对于我的容器 "DebianJessie"，我会运行下面的命令：
|
||||
|
||||
```
|
||||
$ semanage fcontext -a -t svirt_sandbox_file_t "/home/johnmh/DebianJessie(/.*)?"
|
||||
$ restorecon -R /home/johnmh/DebianJessie/
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/container-technologies-fedora-systemd-nspawn/
|
||||
|
||||
作者：[John M. Harris, Jr.][a]
|
||||
译者：[ChrisLeeGit](https://github.com/chrisleegit)
|
||||
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/container-technologies-fedora-systemd-nspawn/
|
||||
[1]: https://en.wikipedia.org/wiki/Virtual_machine
|
||||
@ -0,0 +1,63 @@
|
||||
IT 运行在云端，而云运行在 Linux 上。你怎么看？
|
||||
===================================================================
|
||||
|
||||
> IT 正在逐渐迁移到云端。那又是什么驱动了云呢？答案是 Linux。 当连微软的 Azure 都开始拥抱 Linux 时，你就应该知道这一切都已经改变了。
|
||||
|
||||
|
||||
|
||||
*图片： ZDNet*
|
||||
|
||||
不管你接不接受， 云正在接管 IT 已经成为现实。 我们这几年见证了 [ 云在内部 IT 的崛起 ][1] 。 那又是什么驱动了云呢？ 答案是 Linux 。
|
||||
|
||||
[Uptime Institute][2] 最近对 1000 个 IT 决策者进行了调查，发现约 50% 左右的资深企业 IT 决策者认为在将来[大部分的 IT 工作应该放在云上 ][3] 或托管网站上。在这个调查中，23% 的人认为这种改变即将发生在明年，有 70% 的人则认为这种情况会在四年内出现。
|
||||
|
||||
这一点都不奇怪。 我们中的许多人仍热衷于我们的物理服务器和机架， 但一般运营一个自己的数据中心并不会产生任何的经济效益。
|
||||
|
||||
很简单， 只需要对比你[运行在你自己的硬件上的资本费用（CAPEX）和使用云的业务费用（OPEX）][4]即可。 但这并不是说你应该把所有的东西都一股脑外包出去，而是说在大多数情况下你应该把许多工作都迁移到云端。
|
||||
|
||||
相应地，如果你想充分地利用云，你就得了解 Linux 。
|
||||
|
||||
[亚马逊的 AWS][5]、 [Apache CloudStack][6]、 [Rackspace][7]、[谷歌的 GCP][8] 以及 [ OpenStack ][9] 的核心都是运行在 Linux 上的。那么结果如何？截至到 2014 年， [在 Linux 服务器上部署的应用达到所有企业的 79% ][10]，而 在 Windows 服务器上部署的则跌到 36%。从那时起， Linux 就获得了更多的发展动力。
|
||||
|
||||
即便是微软自身也明白这一点。
|
||||
|
||||
Azure 的技术主管 Mark Russinovich 曾说，仅仅在过去的几年内微软就从[四分之一的 Azure 虚拟机运行在 Linux 上][11] 变为[将近三分之一的 Azure 虚拟机运行在 Linux 上][12]。
|
||||
|
||||
试想一下。微软，一家正逐渐将[云变为自身财政收入的主要来源][13] 的公司，其三分之一的云产业依靠于 Linux 。
|
||||
|
||||
即使是到目前为止， 这些不论喜欢或者不喜欢微软的人都很难想象得到[微软会从一家以商业软件为基础的软件公司转变为一家开源的、基于云服务的企业][14] 。
|
||||
|
||||
Linux 对于这些专用服务器机房的渗透甚至比它刚开始的时候更深了。 举个例子， [Docker 最近发行了其在 Windows 10 和 Mac OS X 上的公测版本 ][15] 。 这难道是意味着 [Docker][16] 将会把其同名的容器服务移植到 Windows 10 和 Mac 上吗？ 并不是的。
|
||||
|
||||
在这两个平台上， Docker 只是运行在一个 Linux 虚拟机内部。 在 Mac OS 上是 HyperKit ，在 Windows 上则是 Hyper-V 。 在图形界面上可能看起来就像另一个 Mac 或 Windows 上的应用， 但在其内部的容器仍然是运行在 Linux 上的。
|
||||
|
||||
所以，就像大量的安卓手机和 Chromebook 的用户压根就不知道他们所运行的是 Linux 系统一样。这些 IT 用户也会随之悄然地迁移到 Linux 和云上。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.zdnet.com/article/it-runs-on-the-cloud-and-the-cloud-runs-on-linux-any-questions/
|
||||
|
||||
作者：[Steven J. Vaughan-Nichols][a]
|
||||
译者：[chenxinlong](https://github.com/chenxinlong)
|
||||
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]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/
|
||||
[1]: http://www.zdnet.com/article/2014-the-year-the-cloud-killed-the-datacenter/
|
||||
[2]: https://uptimeinstitute.com/
|
||||
[3]: http://www.zdnet.com/article/move-to-cloud-accelerating-faster-than-thought-survey-finds/
|
||||
[4]: http://www.zdnet.com/article/rethinking-capex-and-opex-in-a-cloud-centric-world/
|
||||
[5]: https://aws.amazon.com/
|
||||
[6]: https://cloudstack.apache.org/
|
||||
[7]: https://www.rackspace.com/en-us
|
||||
[8]: https://cloud.google.com/
|
||||
[9]: http://www.openstack.org/
|
||||
[10]: http://www.zdnet.com/article/linux-foundation-finds-enterprise-linux-growing-at-windows-expense/
|
||||
[11]: http://news.microsoft.com/bythenumbers/azure-virtual
|
||||
[12]: http://www.zdnet.com/article/microsoft-nearly-one-in-three-azure-virtual-machines-now-are-running-linux/
|
||||
[13]: http://www.zdnet.com/article/microsofts-q3-azure-commercial-cloud-strong-but-earnings-revenue-light/
|
||||
[14]: http://www.zdnet.com/article/why-microsoft-is-turning-into-an-open-source-company/
|
||||
[15]: http://www.zdnet.com/article/new-docker-betas-for-azure-windows-10-now-available/
|
||||
[16]: http://www.docker.com/
|
||||
|
||||
31
published/20160630 What makes up the Fedora kernel.md
Normal file
31
published/20160630 What makes up the Fedora kernel.md
Normal file
@ -0,0 +1,31 @@
|
||||
Fedora 内核是由什么构成的？
|
||||
====================================
|
||||
|
||||
|
||||
|
||||
每个 Fedora 系统都运行着一个内核。许多代码片段组合在一起使之成为现实。
|
||||
|
||||
每个 Fedora 内核都起始于一个来自于[上游社区][1]的基线版本——通常称之为 vanilla 内核。上游内核就是标准。（Fedora 的）目标是包含尽可能多的上游代码，这样使得 bug 修复和 API 更新更加容易，同时也会有更多的人审查代码。理想情况下，Fedora 能够直接获取 kernel.org 的内核，然后发送给所有用户。
|
||||
|
||||
现实情况是，使用 vanilla 内核并不能完全满足 Fedora。Vanilla 内核可能并不支持一些 Fedora 用户希望拥有的功能。用户接收的 [Fedora 内核] 是在 vanilla 内核之上打了很多补丁的内核。这些补丁被认为“不在树上（out of tree）”。许多这些位于补丁树之外的补丁都不会存在太久。如果某补丁能够修复一个问题，那么该补丁可能会被合并到 Fedora 树，以便用户能够更快地收到修复。当内核变基到一个新版本时，在新版本中的补丁都将被清除。
|
||||
|
||||
一些补丁会在 Fedora 内核树上存在很长时间。一个很好的例子是，安全启动补丁就是这类补丁。这些补丁提供了 Fedora 希望支持的功能，即使上游社区还没有接受它们。保持这些补丁更新是需要付出很多努力的，所以 Fedora 尝试减少不被上游内核维护者接受的补丁数量。
|
||||
|
||||
通常来说，想要在 Fedora 内核中获得一个补丁的最佳方法是先给 [Linux 内核邮件列表（LKML）][3] 发送补丁，然后请求将该补丁包含到 Fedora 中。如果某个维护者接受了补丁，就意味着 Fedora 内核树中将来很有可能会包含该补丁。一些来自于 GitHub 等地方的还没有提交给 LKML 的补丁是不可能进入内核树的。首先向 LKML 发送补丁是非常重要的，它能确保 Fedora 内核树中携带的补丁是功能正常的。如果没有社区审查，Fedora 最终携带的补丁将会充满 bug 并会导致问题。
|
||||
|
||||
Fedora 内核中包含的代码来自许多地方。一切都需要提供最佳的体验。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/makes-fedora-kernel/
|
||||
|
||||
作者：[Laura Abbott][a]
|
||||
译者：[ChrisLeeGit](https://github.com/chrisleegit)
|
||||
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/makes-fedora-kernel/
|
||||
[1]: http://www.kernel.org/
|
||||
[2]: http://pkgs.fedoraproject.org/cgit/rpms/kernel.git/
|
||||
[3]: http://www.labbott.name/blog/2015/10/02/the-art-of-communicating-with-lkml/
|
||||
@ -0,0 +1,144 @@
|
||||
如何在 Ubuntu 上建立网桥
|
||||
=======================================================================
|
||||
|
||||
> 作为一个 Ubuntu 16.04 LTS 的初学者。如何在 Ubuntu 14.04 和 16.04 的主机上建立网桥呢？
|
||||
|
||||
顾名思义，网桥的作用是通过物理接口连接内部和外部网络。对于虚拟端口或者 LXC/KVM/Xen/容器来说，这非常有用。网桥虚拟端口看起来是网络上的一个常规设备。在这个教程中，我将会介绍如何在 Ubuntu 服务器上通过 bridge-utils (brctl) 命令行来配置 Linux 网桥。
|
||||
|
||||
### 网桥化的网络示例
|
||||
|
||||
|
||||
|
||||
*图 01: Kvm/Xen/LXC 容器网桥示例 (br0)*
|
||||
|
||||
在这个例子中，eth0 和 eth1 是物理网络接口。eth0 连接着局域网，eth1 连接着上游路由器和互联网。
|
||||
|
||||
### 安装 bridge-utils
|
||||
|
||||
使用 [apt-get 命令][1] 安装 bridge-utils：
|
||||
|
||||
```
|
||||
$ sudo apt-get install bridge-utils
|
||||
```
|
||||
|
||||
或者
|
||||
|
||||
````
|
||||
$ sudo apt install bridge-utils
|
||||
```
|
||||
|
||||
样例输出:
|
||||
|
||||
|
||||
|
||||
*图 02: Ubuntu 安装 bridge-utils 包*
|
||||
|
||||
### 在 Ubuntu 服务器上创建网桥
|
||||
|
||||
使用你熟悉的文本编辑器修改 `/etc/network/interfaces` ，例如 vi 或者 nano ：
|
||||
|
||||
```
|
||||
$ sudo cp /etc/network/interfaces /etc/network/interfaces.bakup-1-july-2016
|
||||
$ sudo vi /etc/network/interfaces
|
||||
```
|
||||
|
||||
接下来设置 eth1 并且将它映射到 br1 ，输入如下（删除或者注释所有 eth1 相关配置）：
|
||||
|
||||
```
|
||||
# br1 使用静态公网 IP 地址，并以 ISP 的路由器作为网关
|
||||
auto br1
|
||||
iface br1 inet static
|
||||
address 208.43.222.51
|
||||
network 255.255.255.248
|
||||
netmask 255.255.255.0
|
||||
broadcast 208.43.222.55
|
||||
gateway 208.43.222.49
|
||||
bridge_ports eth1
|
||||
bridge_stp off
|
||||
bridge_fd 0
|
||||
bridge_maxwait 0
|
||||
```
|
||||
|
||||
接下来设置 eth0 并将它映射到 br0，输入如下（删除或者注释所有 eth0 相关配置）：
|
||||
|
||||
```
|
||||
auto br0
|
||||
iface br0 inet static
|
||||
address 10.18.44.26
|
||||
netmask 255.255.255.192
|
||||
broadcast 10.18.44.63
|
||||
dns-nameservers 10.0.80.11 10.0.80.12
|
||||
# set static route for LAN
|
||||
post-up route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.18.44.1
|
||||
post-up route add -net 161.26.0.0 netmask 255.255.0.0 gw 10.18.44.1
|
||||
bridge_ports eth0
|
||||
bridge_stp off
|
||||
bridge_fd 0
|
||||
bridge_maxwait 0
|
||||
```
|
||||
|
||||
### 关于 br0 和 DHCP 的一点说明
|
||||
|
||||
如果使用 DHCP ，配置选项是这样的：
|
||||
|
||||
```
|
||||
auto br0
|
||||
iface br0 inet dhcp
|
||||
bridge_ports eth0
|
||||
bridge_stp off
|
||||
bridge_fd 0
|
||||
bridge_maxwait 0
|
||||
```
|
||||
|
||||
保存并且关闭文件。
|
||||
|
||||
### 重启服务器或者网络服务
|
||||
|
||||
你需要重启服务器或者输入下列命令来重启网络服务（在 SSH 登录的会话中这可能不管用）：
|
||||
|
||||
```
|
||||
$ sudo systemctl restart networking
|
||||
```
|
||||
|
||||
如果你证使用 Ubuntu 14.04 LTS 或者更老的没有 systemd 的系统，输入：
|
||||
|
||||
```
|
||||
$ sudo /etc/init.d/restart networking
|
||||
```
|
||||
|
||||
### 验证网络配置成功
|
||||
|
||||
使用 ping/ip 命令来验证 LAN 和 WAN 网络接口运行正常：
|
||||
```
|
||||
# 查看 br0 和 br1
|
||||
ip a show
|
||||
# 查看路由信息
|
||||
ip r
|
||||
# ping 外部站点
|
||||
ping -c 2 cyberciti.biz
|
||||
# ping 局域网服务器
|
||||
ping -c 2 10.0.80.12
|
||||
```
|
||||
|
||||
样例输出：
|
||||
|
||||
|
||||
|
||||
*图 03: 验证网桥的以太网连接*
|
||||
|
||||
现在，你就可以配置 br0 和 br1 来让 XEN/KVM/LXC 容器访问因特网或者私有局域网了。再也没有必要去设置特定路由或者 iptables 的 SNAT 规则了。
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.cyberciti.biz/faq/how-to-create-bridge-interface-ubuntu-linux/
|
||||
|
||||
作者：[VIVEK GITE][a]
|
||||
译者：[MikeCoder](https://github.com/MikeCoder)
|
||||
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://twitter.com/nixcraft
|
||||
[1]: http://www.cyberciti.biz/tips/linux-debian-package-management-cheat-sheet.html
|
||||
|
||||
@ -1,7 +1,7 @@
|
||||
使用 Python 创建你自己的 Shell：Part I
|
||||
使用 Python 创建你自己的 Shell （一）
|
||||
==========================================
|
||||
|
||||
我很想知道一个 shell （像 bash，csh 等）内部是如何工作的。为了满足自己的好奇心，我使用 Python 实现了一个名为 **yosh** （Your Own Shell）的 Shell。本文章所介绍的概念也可以应用于其他编程语言。
|
||||
我很想知道一个 shell （像 bash，csh 等）内部是如何工作的。于是为了满足自己的好奇心，我使用 Python 实现了一个名为 **yosh** （Your Own Shell）的 Shell。本文章所介绍的概念也可以应用于其他编程语言。
|
||||
|
||||
（提示：你可以在[这里](https://github.com/supasate/yosh)查找本博文使用的源代码，代码以 MIT 许可证发布。在 Mac OS X 10.11.5 上，我使用 Python 2.7.10 和 3.4.3 进行了测试。它应该可以运行在其他类 Unix 环境，比如 Linux 和 Windows 上的 Cygwin。）
|
||||
|
||||
@ -20,15 +20,15 @@ yosh_project
|
||||
|
||||
`yosh_project` 为项目根目录（你也可以把它简单命名为 `yosh`）。
|
||||
|
||||
`yosh` 为包目录，且 `__init__.py` 可以使它成为与包目录名字相同的包（如果你不写 Python，可以忽略它。）
|
||||
`yosh` 为包目录，且 `__init__.py` 可以使它成为与包的目录名字相同的包（如果你不用 Python 编写的话，可以忽略它。）
|
||||
|
||||
`shell.py` 是我们主要的脚本文件。
|
||||
|
||||
### 步骤 1：Shell 循环
|
||||
|
||||
当启动一个 shell，它会显示一个命令提示符并等待你的命令输入。在接收了输入的命令并执行它之后（稍后文章会进行详细解释），你的 shell 会重新回到循环，等待下一条指令。
|
||||
当启动一个 shell，它会显示一个命令提示符并等待你的命令输入。在接收了输入的命令并执行它之后（稍后文章会进行详细解释），你的 shell 会重新回到这里，并循环等待下一条指令。
|
||||
|
||||
在 `shell.py`，我们会以一个简单的 mian 函数开始，该函数调用了 shell_loop() 函数，如下：
|
||||
在 `shell.py` 中，我们会以一个简单的 main 函数开始，该函数调用了 shell_loop() 函数，如下：
|
||||
|
||||
```
|
||||
def shell_loop():
|
||||
@ -43,7 +43,7 @@ if __name__ == "__main__":
|
||||
main()
|
||||
```
|
||||
|
||||
接着，在 `shell_loop()`，为了指示循环是否继续或停止，我们使用了一个状态标志。在循环的开始，我们的 shell 将显示一个命令提示符，并等待读取命令输入。
|
||||
接着，在 `shell_loop()` 中，为了指示循环是否继续或停止，我们使用了一个状态标志。在循环的开始，我们的 shell 将显示一个命令提示符，并等待读取命令输入。
|
||||
|
||||
```
|
||||
import sys
|
||||
@ -56,15 +56,15 @@ def shell_loop():
|
||||
status = SHELL_STATUS_RUN
|
||||
|
||||
while status == SHELL_STATUS_RUN:
|
||||
# Display a command prompt
|
||||
### 显示命令提示符
|
||||
sys.stdout.write('> ')
|
||||
sys.stdout.flush()
|
||||
|
||||
# Read command input
|
||||
### 读取命令输入
|
||||
cmd = sys.stdin.readline()
|
||||
```
|
||||
|
||||
之后，我们切分命令输入并进行执行（我们即将实现`命令切分`和`执行`函数）。
|
||||
之后，我们切分命令（tokenize）输入并进行执行（execute）（我们即将实现 `tokenize` 和 `execute` 函数）。
|
||||
|
||||
因此，我们的 shell_loop() 会是如下这样：
|
||||
|
||||
@ -79,33 +79,33 @@ def shell_loop():
|
||||
status = SHELL_STATUS_RUN
|
||||
|
||||
while status == SHELL_STATUS_RUN:
|
||||
# Display a command prompt
|
||||
### 显示命令提示符
|
||||
sys.stdout.write('> ')
|
||||
sys.stdout.flush()
|
||||
|
||||
# Read command input
|
||||
### 读取命令输入
|
||||
cmd = sys.stdin.readline()
|
||||
|
||||
# Tokenize the command input
|
||||
### 切分命令输入
|
||||
cmd_tokens = tokenize(cmd)
|
||||
|
||||
# Execute the command and retrieve new status
|
||||
### 执行该命令并获取新的状态
|
||||
status = execute(cmd_tokens)
|
||||
```
|
||||
|
||||
这就是我们整个 shell 循环。如果我们使用 `python shell.py` 启动我们的 shell，它会显示命令提示符。然而如果我们输入命令并按回车，它会抛出错误，因为我们还没定义`命令切分`函数。
|
||||
这就是我们整个 shell 循环。如果我们使用 `python shell.py` 启动我们的 shell，它会显示命令提示符。然而如果我们输入命令并按回车，它会抛出错误，因为我们还没定义 `tokenize` 函数。
|
||||
|
||||
为了退出 shell，可以尝试输入 ctrl-c。稍后我将解释如何以优雅的形式退出 shell。
|
||||
|
||||
### 步骤 2：命令切分
|
||||
### 步骤 2：命令切分（tokenize）
|
||||
|
||||
当用户在我们的 shell 中输入命令并按下回车键，该命令将会是一个包含命令名称及其参数的很长的字符串。因此，我们必须切分该字符串（分割一个字符串为多个标记）。
|
||||
当用户在我们的 shell 中输入命令并按下回车键，该命令将会是一个包含命令名称及其参数的长字符串。因此，我们必须切分该字符串（分割一个字符串为多个元组）。
|
||||
|
||||
咋一看似乎很简单。我们或许可以使用 `cmd.split()`，以空格分割输入。它对类似 `ls -a my_folder` 的命令起作用，因为它能够将命令分割为一个列表 `['ls', '-a', 'my_folder']`，这样我们便能轻易处理它们了。
|
||||
|
||||
然而，也有一些类似 `echo "Hello World"` 或 `echo 'Hello World'` 以单引号或双引号引用参数的情况。如果我们使用 cmd.spilt，我们将会得到一个存有 3 个标记的列表 `['echo', '"Hello', 'World"']` 而不是 2 个标记的列表 `['echo', 'Hello World']`。
|
||||
|
||||
幸运的是，Python 提供了一个名为 `shlex` 的库，它能够帮助我们效验如神地分割命令。（提示：我们也可以使用正则表达式，但它不是本文的重点。）
|
||||
幸运的是，Python 提供了一个名为 `shlex` 的库，它能够帮助我们如魔法般地分割命令。（提示：我们也可以使用正则表达式，但它不是本文的重点。）
|
||||
|
||||
|
||||
```
|
||||
@ -120,23 +120,23 @@ def tokenize(string):
|
||||
...
|
||||
```
|
||||
|
||||
然后我们将这些标记发送到执行进程。
|
||||
然后我们将这些元组发送到执行进程。
|
||||
|
||||
### 步骤 3：执行
|
||||
|
||||
这是 shell 中核心和有趣的一部分。当 shell 执行 `mkdir test_dir` 时，到底发生了什么？（提示： `mkdir` 是一个带有 `test_dir` 参数的执行程序，用于创建一个名为 `test_dir` 的目录。）
|
||||
这是 shell 中核心而有趣的一部分。当 shell 执行 `mkdir test_dir` 时，到底发生了什么？（提示： `mkdir` 是一个带有 `test_dir` 参数的执行程序，用于创建一个名为 `test_dir` 的目录。）
|
||||
|
||||
`execvp` 是涉及这一步的首个函数。在我们解释 `execvp` 所做的事之前，让我们看看它的实际效果。
|
||||
`execvp` 是这一步的首先需要的函数。在我们解释 `execvp` 所做的事之前，让我们看看它的实际效果。
|
||||
|
||||
```
|
||||
import os
|
||||
...
|
||||
|
||||
def execute(cmd_tokens):
|
||||
# Execute command
|
||||
### 执行命令
|
||||
os.execvp(cmd_tokens[0], cmd_tokens)
|
||||
|
||||
# Return status indicating to wait for next command in shell_loop
|
||||
### 返回状态以告知在 shell_loop 中等待下一个命令
|
||||
return SHELL_STATUS_RUN
|
||||
|
||||
...
|
||||
@ -144,11 +144,11 @@ def execute(cmd_tokens):
|
||||
|
||||
再次尝试运行我们的 shell，并输入 `mkdir test_dir` 命令，接着按下回车键。
|
||||
|
||||
在我们敲下回车键之后，问题是我们的 shell 会直接退出而不是等待下一个命令。然而，目标正确地被创建。
|
||||
在我们敲下回车键之后，问题是我们的 shell 会直接退出而不是等待下一个命令。然而，目录正确地创建了。
|
||||
|
||||
因此，`execvp` 实际上做了什么？
|
||||
|
||||
`execvp` 是系统调用 `exec` 的一个变体。第一个参数是程序名字。`v` 表示第二个参数是一个程序参数列表（可变参数）。`p` 表示环境变量 `PATH` 会被用于搜索给定的程序名字。在我们上一次的尝试中，它将会基于我们的 `PATH` 环境变量查找`mkdir` 程序。
|
||||
`execvp` 是系统调用 `exec` 的一个变体。第一个参数是程序名字。`v` 表示第二个参数是一个程序参数列表（参数数量可变）。`p` 表示将会使用环境变量 `PATH` 搜索给定的程序名字。在我们上一次的尝试中，它将会基于我们的 `PATH` 环境变量查找`mkdir` 程序。
|
||||
|
||||
（还有其他 `exec` 变体，比如 execv、execvpe、execl、execlp、execlpe；你可以 google 它们获取更多的信息。）
|
||||
|
||||
@ -158,7 +158,7 @@ def execute(cmd_tokens):
|
||||
|
||||
因此，我们需要其他的系统调用来解决问题：`fork`。
|
||||
|
||||
`fork` 会开辟新的内存并拷贝当前进程到一个新的进程。我们称这个新的进程为**子进程**，调用者进程为**父进程**。然后，子进程内存会被替换为被执行的程序。因此，我们的 shell，也就是父进程，可以免受内存替换的危险。
|
||||
`fork` 会分配新的内存并拷贝当前进程到一个新的进程。我们称这个新的进程为**子进程**，调用者进程为**父进程**。然后，子进程内存会被替换为被执行的程序。因此，我们的 shell，也就是父进程，可以免受内存替换的危险。
|
||||
|
||||
让我们看看修改的代码。
|
||||
|
||||
@ -166,34 +166,34 @@ def execute(cmd_tokens):
|
||||
...
|
||||
|
||||
def execute(cmd_tokens):
|
||||
# Fork a child shell process
|
||||
# If the current process is a child process, its `pid` is set to `0`
|
||||
# else the current process is a parent process and the value of `pid`
|
||||
# is the process id of its child process.
|
||||
### 分叉一个子 shell 进程
|
||||
### 如果当前进程是子进程，其 `pid` 被设置为 `0`
|
||||
### 否则当前进程是父进程的话，`pid` 的值
|
||||
### 是其子进程的进程 ID。
|
||||
pid = os.fork()
|
||||
|
||||
if pid == 0:
|
||||
# Child process
|
||||
# Replace the child shell process with the program called with exec
|
||||
### 子进程
|
||||
### 用被 exec 调用的程序替换该子进程
|
||||
os.execvp(cmd_tokens[0], cmd_tokens)
|
||||
elif pid > 0:
|
||||
# Parent process
|
||||
### 父进程
|
||||
while True:
|
||||
# Wait response status from its child process (identified with pid)
|
||||
### 等待其子进程的响应状态（以进程 ID 来查找）
|
||||
wpid, status = os.waitpid(pid, 0)
|
||||
|
||||
# Finish waiting if its child process exits normally
|
||||
# or is terminated by a signal
|
||||
### 当其子进程正常退出时
|
||||
### 或者其被信号中断时，结束等待状态
|
||||
if os.WIFEXITED(status) or os.WIFSIGNALED(status):
|
||||
break
|
||||
|
||||
# Return status indicating to wait for next command in shell_loop
|
||||
### 返回状态以告知在 shell_loop 中等待下一个命令
|
||||
return SHELL_STATUS_RUN
|
||||
|
||||
...
|
||||
```
|
||||
|
||||
当我们的父进程调用 `os.fork()`时，你可以想象所有的源代码被拷贝到了新的子进程。此时此刻，父进程和子进程看到的是相同的代码，且并行运行着。
|
||||
当我们的父进程调用 `os.fork()` 时，你可以想象所有的源代码被拷贝到了新的子进程。此时此刻，父进程和子进程看到的是相同的代码，且并行运行着。
|
||||
|
||||
如果运行的代码属于子进程，`pid` 将为 `0`。否则，如果运行的代码属于父进程，`pid` 将会是子进程的进程 id。
|
||||
|
||||
@ -205,13 +205,13 @@ def execute(cmd_tokens):
|
||||
|
||||
现在，你可以尝试运行我们的 shell 并输入 `mkdir test_dir2`。它应该可以正确执行。我们的主 shell 进程仍然存在并等待下一条命令。尝试执行 `ls`，你可以看到已创建的目录。
|
||||
|
||||
但是，这里仍有许多问题。
|
||||
但是，这里仍有一些问题。
|
||||
|
||||
第一，尝试执行 `cd test_dir2`，接着执行 `ls`。它应该会进入到一个空的 `test_dir2` 目录。然而，你将会看到目录并没有变为 `test_dir2`。
|
||||
|
||||
第二，我们仍然没有办法优雅地退出我们的 shell。
|
||||
|
||||
我们将会在 [Part 2][1] 解决诸如此类的问题。
|
||||
我们将会在 [第二部分][1] 解决诸如此类的问题。
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
@ -219,8 +219,8 @@ def execute(cmd_tokens):
|
||||
via: https://hackercollider.com/articles/2016/07/05/create-your-own-shell-in-python-part-1/
|
||||
|
||||
作者：[Supasate Choochaisri][a]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
译者：[cposture](https://github.com/cposture)
|
||||
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
|
||||
|
||||
211
published/20160706 Create Your Own Shell in Python - Part II.md
Normal file
211
published/20160706 Create Your Own Shell in Python - Part II.md
Normal file
@ -0,0 +1,211 @@
|
||||
使用 Python 创建你自己的 Shell（下）
|
||||
===========================================
|
||||
|
||||
在[上篇][1]中，我们已经创建了一个 shell 主循环、切分了命令输入，以及通过 `fork` 和 `exec` 执行命令。在这部分，我们将会解决剩下的问题。首先，`cd test_dir2` 命令无法修改我们的当前目录。其次，我们仍无法优雅地从 shell 中退出。
|
||||
|
||||
### 步骤 4：内置命令
|
||||
|
||||
“`cd test_dir2` 无法修改我们的当前目录” 这句话是对的，但在某种意义上也是错的。在执行完该命令之后，我们仍然处在同一目录，从这个意义上讲，它是对的。然而，目录实际上已经被修改，只不过它是在子进程中被修改。
|
||||
|
||||
还记得我们分叉（fork）了一个子进程，然后执行命令，执行命令的过程没有发生在父进程上。结果是我们只是改变了子进程的当前目录，而不是父进程的目录。
|
||||
|
||||
然后子进程退出，而父进程在原封不动的目录下继续运行。
|
||||
|
||||
因此，这类与 shell 自己相关的命令必须是内置命令。它必须在 shell 进程中执行而不是在分叉中（forking）。
|
||||
|
||||
#### cd
|
||||
|
||||
让我们从 `cd` 命令开始。
|
||||
|
||||
我们首先创建一个 `builtins` 目录。每一个内置命令都会被放进这个目录中。
|
||||
|
||||
```shell
|
||||
yosh_project
|
||||
|-- yosh
|
||||
|-- builtins
|
||||
| |-- __init__.py
|
||||
| |-- cd.py
|
||||
|-- __init__.py
|
||||
|-- shell.py
|
||||
```
|
||||
|
||||
在 `cd.py` 中，我们通过使用系统调用 `os.chdir` 实现自己的 `cd` 命令。
|
||||
|
||||
```python
|
||||
import os
|
||||
from yosh.constants import *
|
||||
|
||||
def cd(args):
|
||||
os.chdir(args[0])
|
||||
|
||||
return SHELL_STATUS_RUN
|
||||
```
|
||||
|
||||
注意，我们会从内置函数返回 shell 的运行状态。所以，为了能够在项目中继续使用常量，我们将它们移至 `yosh/constants.py`。
|
||||
|
||||
```shell
|
||||
yosh_project
|
||||
|-- yosh
|
||||
|-- builtins
|
||||
| |-- __init__.py
|
||||
| |-- cd.py
|
||||
|-- __init__.py
|
||||
|-- constants.py
|
||||
|-- shell.py
|
||||
```
|
||||
|
||||
在 `constants.py` 中，我们将状态常量都放在这里。
|
||||
|
||||
```python
|
||||
SHELL_STATUS_STOP = 0
|
||||
SHELL_STATUS_RUN = 1
|
||||
```
|
||||
|
||||
现在，我们的内置 `cd` 已经准备好了。让我们修改 `shell.py` 来处理这些内置函数。
|
||||
|
||||
```python
|
||||
...
|
||||
### 导入常量
|
||||
from yosh.constants import *
|
||||
|
||||
### 使用哈希映射来存储内建的函数名及其引用
|
||||
built_in_cmds = {}
|
||||
|
||||
def tokenize(string):
|
||||
return shlex.split(string)
|
||||
|
||||
def execute(cmd_tokens):
|
||||
### 从元组中分拆命令名称与参数
|
||||
cmd_name = cmd_tokens[0]
|
||||
cmd_args = cmd_tokens[1:]
|
||||
|
||||
### 如果该命令是一个内建命令，使用参数调用该函数
|
||||
if cmd_name in built_in_cmds:
|
||||
return built_in_cmds[cmd_name](cmd_args)
|
||||
|
||||
...
|
||||
```
|
||||
|
||||
我们使用一个 python 字典变量 `built_in_cmds` 作为哈希映射（hash map），以存储我们的内置函数。我们在 `execute` 函数中提取命令的名字和参数。如果该命令在我们的哈希映射中，则调用对应的内置函数。
|
||||
|
||||
（提示：`built_in_cmds[cmd_name]` 返回能直接使用参数调用的函数引用。)
|
||||
|
||||
我们差不多准备好使用内置的 `cd` 函数了。最后一步是将 `cd` 函数添加到 `built_in_cmds` 映射中。
|
||||
|
||||
```
|
||||
...
|
||||
### 导入所有内建函数引用
|
||||
from yosh.builtins import *
|
||||
|
||||
...
|
||||
|
||||
### 注册内建函数到内建命令的哈希映射中
|
||||
def register_command(name, func):
|
||||
built_in_cmds[name] = func
|
||||
|
||||
|
||||
### 在此注册所有的内建命令
|
||||
def init():
|
||||
register_command("cd", cd)
|
||||
|
||||
|
||||
def main():
|
||||
###在开始主循环之前初始化 shell
|
||||
init()
|
||||
shell_loop()
|
||||
```
|
||||
|
||||
我们定义了 `register_command` 函数，以添加一个内置函数到我们内置的命令哈希映射。接着，我们定义 `init` 函数并且在这里注册内置的 `cd` 函数。
|
||||
|
||||
注意这行 `register_command("cd", cd)` 。第一个参数为命令的名字。第二个参数为一个函数引用。为了能够让第二个参数 `cd` 引用到 `yosh/builtins/cd.py` 中的 `cd` 函数引用，我们必须将以下这行代码放在 `yosh/builtins/__init__.py` 文件中。
|
||||
|
||||
```
|
||||
from yosh.builtins.cd import *
|
||||
```
|
||||
|
||||
因此，在 `yosh/shell.py` 中，当我们从 `yosh.builtins` 导入 `*` 时，我们可以得到已经通过 `yosh.builtins` 导入的 `cd` 函数引用。
|
||||
|
||||
我们已经准备好了代码。让我们尝试在 `yosh` 同级目录下以模块形式运行我们的 shell，`python -m yosh.shell`。
|
||||
|
||||
现在，`cd` 命令可以正确修改我们的 shell 目录了，同时非内置命令仍然可以工作。非常好！
|
||||
|
||||
#### exit
|
||||
|
||||
最后一块终于来了：优雅地退出。
|
||||
|
||||
我们需要一个可以修改 shell 状态为 `SHELL_STATUS_STOP` 的函数。这样，shell 循环可以自然地结束，shell 将到达终点而退出。
|
||||
|
||||
和 `cd` 一样，如果我们在子进程中分叉并执行 `exit` 函数，其对父进程是不起作用的。因此，`exit` 函数需要成为一个 shell 内置函数。
|
||||
|
||||
让我们从这开始：在 `builtins` 目录下创建一个名为 `exit.py` 的新文件。
|
||||
|
||||
```
|
||||
yosh_project
|
||||
|-- yosh
|
||||
|-- builtins
|
||||
| |-- __init__.py
|
||||
| |-- cd.py
|
||||
| |-- exit.py
|
||||
|-- __init__.py
|
||||
|-- constants.py
|
||||
|-- shell.py
|
||||
```
|
||||
|
||||
`exit.py` 定义了一个 `exit` 函数，该函数仅仅返回一个可以退出主循环的状态。
|
||||
|
||||
```
|
||||
from yosh.constants import *
|
||||
|
||||
def exit(args):
|
||||
return SHELL_STATUS_STOP
|
||||
```
|
||||
|
||||
然后，我们导入位于 `yosh/builtins/__init__.py` 文件的 `exit` 函数引用。
|
||||
|
||||
```
|
||||
from yosh.builtins.cd import *
|
||||
from yosh.builtins.exit import *
|
||||
```
|
||||
|
||||
最后，我们在 `shell.py` 中的 `init()` 函数注册 `exit` 命令。
|
||||
|
||||
```
|
||||
...
|
||||
|
||||
### 在此注册所有的内建命令
|
||||
def init():
|
||||
register_command("cd", cd)
|
||||
register_command("exit", exit)
|
||||
|
||||
...
|
||||
```
|
||||
|
||||
到此为止！
|
||||
|
||||
尝试执行 `python -m yosh.shell`。现在你可以输入 `exit` 优雅地退出程序了。
|
||||
|
||||
### 最后的想法
|
||||
|
||||
我希望你能像我一样享受创建 `yosh` （**y**our **o**wn **sh**ell）的过程。但我的 `yosh` 版本仍处于早期阶段。我没有处理一些会使 shell 崩溃的极端状况。还有很多我没有覆盖的内置命令。为了提高性能，一些非内置命令也可以实现为内置命令（避免新进程创建时间）。同时，大量的功能还没有实现（请看 [公共特性](http://tldp.org/LDP/Bash-Beginners-Guide/html/x7243.html) 和 [不同特性](http://www.tldp.org/LDP/intro-linux/html/x12249.html)）
|
||||
|
||||
我已经在 https://github.com/supasate/yosh 中提供了源代码。请随意 fork 和尝试。
|
||||
|
||||
现在该是创建你真正自己拥有的 Shell 的时候了。
|
||||
|
||||
Happy Coding!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://hackercollider.com/articles/2016/07/06/create-your-own-shell-in-python-part-2/
|
||||
|
||||
作者：[Supasate Choochaisri][a]
|
||||
译者：[cposture](https://github.com/cposture)
|
||||
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://disqus.com/by/supasate_choochaisri/
|
||||
[1]: https://linux.cn/article-7624-1.html
|
||||
[2]: http://tldp.org/LDP/Bash-Beginners-Guide/html/x7243.html
|
||||
[3]: http://www.tldp.org/LDP/intro-linux/html/x12249.html
|
||||
[4]: https://github.com/supasate/yosh
|
||||
200
published/20160722 7 Best Markdown Editors for Linux.md
Normal file
200
published/20160722 7 Best Markdown Editors for Linux.md
Normal file
@ -0,0 +1,200 @@
|
||||
Linux 上 10 个最好的 Markdown 编辑器
|
||||
======================================
|
||||
|
||||
在这篇文章中，我们会点评一些可以在 Linux 上安装使用的最好的 Markdown 编辑器。 你可以找到非常多的 Linux 平台上的 Markdown 编辑器，但是在这里我们将尽可能地为您推荐那些最好的。
|
||||
|
||||
|
||||
|
||||
*Best Linux Markdown Editors*
|
||||
|
||||
对于不了解 Markdown 的人做个简单介绍，Markdown 是由著名的 Aaron Swartz 和 John Gruber 发明的标记语言，其最初的解析器是一个用 Perl 写的简单、轻量的[同名工具][1]。它可以将用户写的纯文本转为可用的 HTML（或 XHTML）。它实际上是一门易读，易写的纯文本语言，以及一个用于将文本转为 HTML 的转换工具。
|
||||
|
||||
希望你先对 Markdown 有一个稍微的了解，接下来让我们逐一列出这些编辑器。
|
||||
|
||||
### 1. Atom
|
||||
|
||||
Atom 是一个现代的、跨平台、开源且强大的文本编辑器，它可以运行在 Linux、Windows 和 MAC OS X 等操作系统上。用户可以在它的基础上进行定制，删减修改任何配置文件。
|
||||
|
||||
它包含了一些非常杰出的特性：
|
||||
|
||||
- 内置软件包管理器
|
||||
- 智能自动补全功能
|
||||
- 提供多窗口操作
|
||||
- 支持查找替换功能
|
||||
- 包含一个文件系统浏览器
|
||||
- 轻松自定义主题
|
||||
- 开源、高度扩展性的软件包等
|
||||
|
||||
|
||||
|
||||
*Atom Markdown Editor for Linux*
|
||||
|
||||
访问主页: <https://atom.io/>
|
||||
|
||||
### 2. GNU Emacs
|
||||
|
||||
Emacs 是 Linux 平台上一款的流行文本编辑器。它是一个非常棒的、具备高扩展性和定制性的 Markdown 语言编辑器。
|
||||
|
||||
它综合了以下这些神奇的特性：
|
||||
|
||||
- 带有丰富的内置文档，包括适合初学者的教程
|
||||
- 有完整的 Unicode 支持，可显示所有的人类符号
|
||||
- 支持内容识别的文本编辑模式
|
||||
- 包括多种文件类型的语法高亮
|
||||
- 可用 Emacs Lisp 或 GUI 对其进行高度定制
|
||||
- 提供了一个包系统可用来下载安装各种扩展等
|
||||
|
||||
|
||||
|
||||
*Emacs Markdown Editor for Linux*
|
||||
|
||||
访问主页: <https://www.gnu.org/software/emacs/>
|
||||
|
||||
### 3. Remarkable
|
||||
|
||||
Remarkable 可能是 Linux 上最好的 Markdown 编辑器了，它也适用于 Windows 操作系统。它的确是是一个卓越且功能齐全的 Markdown 编辑器，为用户提供了一些令人激动的特性。
|
||||
|
||||
一些卓越的特性：
|
||||
|
||||
- 支持实时预览
|
||||
- 支持导出 PDF 和 HTML
|
||||
- 支持 Github Markdown 语法
|
||||
- 支持定制 CSS
|
||||
- 支持语法高亮
|
||||
- 提供键盘快捷键
|
||||
- 高可定制性和其他
|
||||
|
||||
|
||||
|
||||
*Remarkable Markdown Editor for Linux*
|
||||
|
||||
访问主页: <https://remarkableapp.github.io>
|
||||
|
||||
### 4. Haroopad
|
||||
|
||||
Haroopad 是为 Linux，Windows 和 Mac OS X 构建的跨平台 Markdown 文档处理程序。用户可以用它来书写许多专家级格式的文档，包括电子邮件、报告、博客、演示文稿和博客文章等等。
|
||||
|
||||
功能齐全且具备以下的亮点：
|
||||
|
||||
- 轻松导入内容
|
||||
- 支持导出多种格式
|
||||
- 广泛支持博客和邮件
|
||||
- 支持许多数学表达式
|
||||
- 支持 Github Markdown 扩展
|
||||
- 为用户提供了一些令人兴奋的主题、皮肤和 UI 组件等等
|
||||
|
||||
|
||||
|
||||
*Haroopad Markdown Editor for Linux*
|
||||
|
||||
访问主页: <http://pad.haroopress.com/>
|
||||
|
||||
### 5. ReText
|
||||
|
||||
ReText 是为 Linux 和其它几个 POSIX 兼容操作系统提供的简单、轻量、强大的 Markdown 编辑器。它还可以作为一个 reStructuredText 编辑器，并且具有以下的特性：
|
||||
|
||||
- 简单直观的 GUI
|
||||
- 具备高定制性，用户可以自定义语法文件和配置选项
|
||||
- 支持多种配色方案
|
||||
- 支持使用多种数学公式
|
||||
- 启用导出扩展等等
|
||||
|
||||
|
||||
|
||||
*ReText Markdown Editor for Linux*
|
||||
|
||||
访问主页: <https://github.com/retext-project/retext>
|
||||
|
||||
### 6. UberWriter
|
||||
|
||||
UberWriter 是一个简单、易用的 Linux Markdown 编辑器。它的开发受 Mac OS X 上的 iA writer 影响很大，同样它也具备这些卓越的特性：
|
||||
|
||||
- 使用 pandoc 进行所有的文本到 HTML 的转换
|
||||
- 提供了一个简洁的 UI 界面
|
||||
- 提供了一种专心（distraction free）模式，高亮用户最后的句子
|
||||
- 支持拼写检查
|
||||
- 支持全屏模式
|
||||
- 支持用 pandoc 导出 PDF、HTML 和 RTF
|
||||
- 启用语法高亮和数学函数等等
|
||||
|
||||
|
||||
|
||||
*UberWriter Markdown Editor for Linux*
|
||||
|
||||
访问主页: <http://uberwriter.wolfvollprecht.de/>
|
||||
|
||||
### 7. Mark My Words
|
||||
|
||||
Mark My Words 同样也是一个轻量、强大的 Markdown 编辑器。它是一个相对比较新的编辑器，因此提供了包含语法高亮在内的大量的功能，简单和直观的 UI。
|
||||
|
||||
下面是一些棒极了，但还未捆绑到应用中的功能：
|
||||
|
||||
- 实时预览
|
||||
- Markdown 解析和文件 IO
|
||||
- 状态管理
|
||||
- 支持导出 PDF 和 HTML
|
||||
- 监测文件的修改
|
||||
- 支持首选项设置
|
||||
|
||||
|
||||
|
||||
*MarkMyWords Markdown Editor for-Linux*
|
||||
|
||||
访问主页: <https://github.com/voldyman/MarkMyWords>
|
||||
|
||||
### 8. Vim-Instant-Markdown 插件
|
||||
|
||||
Vim 是 Linux 上的一个久经考验的强大、流行而开源的文本编辑器。它用于编程极棒。它也高度支持插件功能，可以让用户为其增加一些其它功能，包括 Markdown 预览。
|
||||
|
||||
有好几种 Vim 的 Markdown 预览插件，但是 [Vim-Instant-Markdown][2] 的表现最佳。
|
||||
|
||||
###9. Bracket-MarkdownPreview 插件
|
||||
|
||||
Brackets 是一个现代、轻量、开源且跨平台的文本编辑器。它特别为 Web 设计和开发而构建。它的一些重要功能包括：支持内联编辑器、实时预览、预处理支持及更多。
|
||||
|
||||
它也是通过插件高度可扩展的，你可以使用 [Bracket-MarkdownPreview][3] 插件来编写和预览 Markdown 文档。
|
||||
|
||||
|
||||
|
||||
*Brackets Markdown Plugin Preview*
|
||||
|
||||
### 10. SublimeText-Markdown 插件
|
||||
|
||||
Sublime Text 是一个精心打造的、流行的、跨平台文本编辑器，用于代码、markdown 和普通文本。它的表现极佳，包括如下令人兴奋的功能：
|
||||
|
||||
- 简洁而美观的 GUI
|
||||
- 支持多重选择
|
||||
- 提供专心模式
|
||||
- 支持窗体分割编辑
|
||||
- 通过 Python 插件 API 支持高度插件化
|
||||
- 完全可定制化，提供命令查找模式
|
||||
|
||||
[SublimeText-Markdown][4] 插件是一个支持格式高亮的软件包，带有一些漂亮的颜色方案。
|
||||
|
||||
|
||||
|
||||
*SublimeText Markdown Plugin Preview*
|
||||
|
||||
### 结论
|
||||
|
||||
通过上面的列表，你大概已经知道要为你的 Linux 桌面下载、安装什么样的 Markdown 编辑器和文档处理程序了。
|
||||
|
||||
请注意，这里提到的最好的 Markdown 编辑器可能对你来说并不是最好的选择。因此你可以通过下面的反馈部分，为我们展示你认为列表中未提及的，并且具备足够的资格的，令人兴奋的 Markdown 编辑器。
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/best-markdown-editors-for-linux/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[Locez](https://github.com/locez)
|
||||
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]: http://www.tecmint.com/author/aaronkili/
|
||||
[1]: https://daringfireball.net/projects/markdown/
|
||||
[2]: https://github.com/suan/vim-instant-markdown
|
||||
[3]: https://github.com/gruehle/MarkdownPreview
|
||||
[4]: https://github.com/SublimeText-Markdown/MarkdownEditing
|
||||
|
||||
@ -0,0 +1,69 @@
|
||||
怎样在 Ubuntu 中修改默认程序
|
||||
==============================================
|
||||
|
||||
|
||||
|
||||
> 简介: 这个新手指南会向你展示如何在 Ubuntu Linux 中修改默认程序
|
||||
|
||||
对于我来说，安装 [VLC 多媒体播放器][1]是[安装完 Ubuntu 16.04 该做的事][2]中最先做的几件事之一。为了能够使我双击一个视频就用 VLC 打开，在我安装完 VLC 之后我会设置它为默认程序。
|
||||
|
||||
作为一个新手，你需要知道如何在 Ubuntu 中修改任何默认程序，这也是我今天在这篇指南中所要讲的。
|
||||
|
||||
### 在 UBUNTU 中修改默认程序
|
||||
|
||||
这里提及的方法适用于所有的 Ubuntu 12.04，Ubuntu 14.04 和Ubuntu 16.04。在 Ubuntu 中，这里有两种基本的方法可以修改默认程序：
|
||||
|
||||
- 通过系统设置
|
||||
- 通过右键菜单
|
||||
|
||||
#### 1.通过系统设置修改 Ubuntu 的默认程序
|
||||
|
||||
进入 Unity 面板并且搜索系统设置（System Settings）：
|
||||
|
||||
|
||||
|
||||
在系统设置（System Settings）中，选择详细选项（Details）：
|
||||
|
||||
|
||||
|
||||
在左边的面板中选择默认程序（Default Applications），你会发现在右边的面板中可以修改默认程序。
|
||||
|
||||
|
||||
|
||||
正如看到的那样，这里只有少数几类的默认程序可以被改变。你可以在这里改变浏览器、邮箱客户端、日历、音乐、视频和相册的默认程序。那其他类型的默认程序怎么修改？
|
||||
|
||||
不要担心，为了修改其他类型的默认程序，我们会用到右键菜单。
|
||||
|
||||
#### 2.通过右键菜单修改默认程序
|
||||
|
||||
如果你使用过 Windows 系统，你应该看见过右键菜单的“打开方式”，可以通过这个来修改默认程序。我们在 Ubuntu 中也有相似的方法。
|
||||
|
||||
右键一个还没有设置默认打开程序的文件，选择“属性（properties）”
|
||||
|
||||
|
||||
|
||||
*从右键菜单中选择属性*
|
||||
|
||||
在这里，你可以选择使用什么程序打开，并且设置为默认程序。
|
||||
|
||||
|
||||
|
||||
*在 Ubuntu 中设置打开 WebP 图片的默认程序为 gThumb*
|
||||
|
||||
小菜一碟不是么？一旦你做完这些，所有同样类型的文件都会用你选择的默认程序打开。
|
||||
|
||||
我很希望这个新手指南对你在修改 Ubuntu 的默认程序时有帮助。如果你有任何的疑问或者建议，可以随时在下面评论。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/change-default-applications-ubuntu/
|
||||
|
||||
作者：[Abhishek Prakash][a]
|
||||
译者：[Locez](https://github.com/locez)
|
||||
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/
|
||||
[1]: http://www.videolan.org/vlc/index.html
|
||||
[2]: https://linux.cn/article-7453-1.html
|
||||
@ -0,0 +1,136 @@
|
||||
Terminix：一个很赞的基于 GTK3 的平铺式 Linux 终端模拟器
|
||||
============================================================
|
||||
|
||||
现在，你可以很容易的找到[大量的 Linux 终端模拟器][1]，每一个都可以给用户留下深刻的印象。
|
||||
|
||||
但是，很多时候，我们会很难根据我们的喜好来找到一款心仪的日常使用的终端模拟器。这篇文章中，我们将会推荐一款叫做 Terminix 的令人激动的终端模拟机。
|
||||
|
||||
|
||||
|
||||
*Terminix Linux 终端模拟器*
|
||||
|
||||
Terminix 是一个使用 VTE GTK+ 3 组件的平铺式终端模拟器。使用 GTK 3 开发的原因主要是为了符合 GNOME HIG（人机接口 Human Interface Guidelines) 标准。另外，Terminix 已经在 GNOME 和 Unity 桌面环境下测试过了，也有用户在其他的 Linux 桌面环境下测试成功。
|
||||
|
||||
和其他的终端模拟器一样，Terminix 有着很多知名的特征，列表如下：
|
||||
|
||||
- 允许用户进行任意的垂直或者水平分屏
|
||||
- 支持拖拽功能来进行重新排布终端
|
||||
- 支持使用拖拽的方式终端从窗口中将脱离出来
|
||||
- 支持终端之间的输入同步，因此，可以在一个终端输入命令，而在另一个终端同步复现
|
||||
- 终端的分组配置可以保存在硬盘，并再次加载
|
||||
- 支持透明背景
|
||||
- 允许使用背景图片
|
||||
- 基于主机和目录来自动切换配置
|
||||
- 支持进程完成的通知信息
|
||||
- 配色方案采用文件存储，同时支持自定义配色方案
|
||||
|
||||
### 如何在 Linux 系统上安装 Terminix
|
||||
|
||||
现在来详细说明一下在不同的 Linux 发行版本上安装 Terminix 的步骤。首先，在此列出 Terminix 在 Linux 所需要的环境需求。
|
||||
|
||||
#### 依赖组件
|
||||
|
||||
为了正常运行，该应用需要使用如下库：
|
||||
|
||||
- GTK 3.14 或者以上版本
|
||||
- GTK VTE 0.42 或者以上版本
|
||||
- Dconf
|
||||
- GSettings
|
||||
- Nautilus 的 iNautilus-Python 插件
|
||||
|
||||
如果你已经满足了如上的系统要求，接下来就是安装 Terminix 的步骤。
|
||||
|
||||
#### 在 RHEL/CentOS 7 或者 Fedora 22-24 上
|
||||
|
||||
首先，你需要通过新建文件 `/etc/yum.repos.d/terminix.repo` 来增加软件仓库，使用你最喜欢的文本编辑器来进行编辑：
|
||||
|
||||
```
|
||||
# vi /etc/yum.repos.d/terminix.repo
|
||||
```
|
||||
|
||||
然后拷贝如下的文字到我们刚新建的文件中：
|
||||
|
||||
```
|
||||
[heikoada-terminix]
|
||||
name=Copr repo for terminix owned by heikoada
|
||||
baseurl=https://copr-be.cloud.fedoraproject.org/results/heikoada/terminix/fedora-$releasever-$basearch/
|
||||
skip_if_unavailable=True
|
||||
gpgcheck=1
|
||||
gpgkey=https://copr-be.cloud.fedoraproject.org/results/heikoada/terminix/pubkey.gpg
|
||||
enabled=1
|
||||
enabled_metadata=1
|
||||
```
|
||||
|
||||
保存文件并退出。
|
||||
|
||||
然后更新你的系统，并且安装 Terminix，步骤如下：
|
||||
|
||||
```
|
||||
---------------- On RHEL/CentOS 7 ----------------
|
||||
# yum update
|
||||
# yum install terminix
|
||||
|
||||
---------------- On Fedora 22-24 ----------------
|
||||
# dnf update
|
||||
# dnf install terminix
|
||||
```
|
||||
|
||||
#### 在 Ubuntu 16.04-14.04 和 Linux Mint 18-17
|
||||
|
||||
虽然没有基于 Debian/Ubuntu 发行版本的官方的软件包，但是你依旧可以通过如下的命令手动安装。
|
||||
|
||||
```
|
||||
$ wget -c https://github.com/gnunn1/terminix/releases/download/1.1.1/terminix.zip
|
||||
$ sudo unzip terminix.zip -d /
|
||||
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas/
|
||||
```
|
||||
|
||||
#### 其它 Linux 发行版
|
||||
|
||||
OpenSUSE 用户可以从默认仓库中安装 Terminix，Arch Linux 用户也可以安装 [AUR Terminix 软件包][2]。
|
||||
|
||||
### Terminix 截图教程
|
||||
|
||||
|
||||
|
||||
*Terminix 终端*
|
||||
|
||||
|
||||
|
||||
*Terminix 终端设置*
|
||||
|
||||
|
||||
|
||||
*Terminix 多终端界面*
|
||||
|
||||
### 如何卸载删除 Terminix
|
||||
|
||||
|
||||
如果你是手动安装的 Terminix 并且想要删除它，那么你可以参照如下的步骤来卸载它。从 [Github 仓库][3]上下载 uninstall.sh，并且给它可执行权限并且执行它：
|
||||
|
||||
```
|
||||
$ wget -c https://github.com/gnunn1/terminix/blob/master/uninstall.sh
|
||||
$ chmod +x uninstall.sh
|
||||
$ sudo sh uninstall.sh
|
||||
```
|
||||
|
||||
但是如果你是通过包管理器安装的 Terminix，你可以使用包管理器来卸载它。
|
||||
|
||||
在这篇介绍中，我们在众多优秀的终端模拟器中发现了一个重要的 Linux 终端模拟器。你可以尝试着去体验下它的新特性，并且可以将它和你现在使用的终端进行比较。
|
||||
|
||||
重要的一点，如果你想得到更多信息或者有疑问，请使用评论区，而且不要忘了，给我一个关于你使用体验的反馈。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/terminix-tiling-terminal-emulator-for-linux/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[MikeCoder](https://github.com/MikeCoder)
|
||||
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]: http://www.tecmint.com/author/aaronkili/
|
||||
[1]: http://www.tecmint.com/linux-terminal-emulators/
|
||||
[2]: https://aur.archlinux.org/packages/terminix
|
||||
[3]: https://github.com/gnunn1/terminix
|
||||
@ -1,14 +1,15 @@
|
||||
LFCS 系列第十一讲：如何使用命令 vgcreate、lvcreate 和 lvextend 管理和创建 LVM
|
||||
============================================================================================
|
||||
========================================================================================
|
||||
|
||||
由于 LFCS 考试中的一些改变已在 2016 年 2 月 2 日生效，我们添加了一些必要的专题到 [LFCS 系列][1]。我们也非常推荐备考的同学，同时阅读 [LFCE 系列][2]。
|
||||
|
||||
|
||||
>LFCS：管理 LVM 和创建 LVM 分区
|
||||
|
||||
在安装 Linux 系统的时候要做的最重要的决定之一便是给系统文件，home 目录等分配空间。在这个地方犯了错，再要增长空间不足的分区，那样既麻烦又有风险。
|
||||
*LFCS：管理 LVM 和创建 LVM 分区*
|
||||
|
||||
**逻辑卷管理** （即 **LVM**）相较于传统的分区管理有许多优点，已经成为大多数（如果不能说全部的话） Linux 发行版安装时的默认选择。LVM 最大的优点应该是能方便的按照你的意愿调整（减小或增大）逻辑分区的大小。
|
||||
在安装 Linux 系统的时候要做的最重要的决定之一便是给系统文件、home 目录等分配空间。在这个地方犯了错，再要扩大空间不足的分区，那样既麻烦又有风险。
|
||||
|
||||
**逻辑卷管理** （**LVM**）相较于传统的分区管理有许多优点，已经成为大多数（如果不能说全部的话） Linux 发行版安装时的默认选择。LVM 最大的优点应该是能方便的按照你的意愿调整（减小或增大）逻辑分区的大小。
|
||||
|
||||
LVM 的组成结构：
|
||||
|
||||
@ -16,7 +17,7 @@ LVM 的组成结构：
|
||||
* 一个用一个或多个物理卷创建出的卷组（**VG**）。可以把一个卷组想象成一个单独的存储单元。
|
||||
* 在一个卷组上可以创建多个逻辑卷。每个逻辑卷相当于一个传统意义上的分区 —— 优点是它的大小可以根据需求重新调整大小，正如之前提到的那样。
|
||||
|
||||
本文，我们将使用三块 **8 GB** 的磁盘（**/dev/sdb**、**/dev/sdc** 和 **/dev/sdd**）分别创建三个物理卷。你既可以直接在设备上创建 PV，也可以先分区在创建。
|
||||
本文，我们将使用三块 **8 GB** 的磁盘（**/dev/sdb**、**/dev/sdc** 和 **/dev/sdd**）分别创建三个物理卷。你既可以直接在整个设备上创建 PV，也可以先分区在创建。
|
||||
|
||||
在这里我们选择第一种方式，如果你决定使用第二种（可以参考本系列[第四讲：创建分区和文件系统][3]）确保每个分区的类型都是 `8e`。
|
||||
|
||||
@ -59,7 +60,8 @@ LVM 的组成结构：
|
||||
由于 `vg00` 是由两个 **8 GB** 的磁盘组成的，所以它将会显示成一个 **16 GB** 的硬盘：
|
||||
|
||||
|
||||
>LVM 卷组列表
|
||||
|
||||
*LVM 卷组列表*
|
||||
|
||||
当谈到创建逻辑卷，空间的分配必须考虑到当下和以后的需求。根据每个逻辑卷的用途来命名是一个好的做法。
|
||||
|
||||
@ -78,7 +80,7 @@ LVM 的组成结构：
|
||||
# lvs
|
||||
```
|
||||
|
||||
或是详细信息，通过：
|
||||
或是查看详细信息，通过：
|
||||
|
||||
```
|
||||
# lvdisplay
|
||||
@ -91,9 +93,10 @@ LVM 的组成结构：
|
||||
```
|
||||
|
||||
|
||||
>逻辑卷列表
|
||||
|
||||
如上图，我们看到 LV 已经被创建成存储设备了（参考 LV Path line）。在使用每个逻辑卷之前，需要先在上面创建文件系统。
|
||||
*逻辑卷列表*
|
||||
|
||||
如上图，我们看到 LV 已经被创建成存储设备了（参考 LV Path 那一行）。在使用每个逻辑卷之前，需要先在上面创建文件系统。
|
||||
|
||||
这里我们拿 ext4 来做举例，因为对于每个 LV 的大小， ext4 既可以增大又可以减小（相对的 xfs 就只允许增大）：
|
||||
|
||||
@ -116,7 +119,8 @@ LVM 的组成结构：
|
||||
```
|
||||
|
||||
|
||||
>减小逻辑卷和卷组
|
||||
|
||||
*减小逻辑卷和卷组*
|
||||
|
||||
在调整逻辑卷的时候，其中包含的减号 `(-)` 或加号 `(+)` 是十分重要的。否则 LV 将会被设置成指定的大小，而非调整指定大小。
|
||||
|
||||
@ -135,7 +139,8 @@ LVM 的组成结构：
|
||||
```
|
||||
|
||||
|
||||
>查看卷组磁盘大小
|
||||
|
||||
*查看卷组磁盘大小*
|
||||
|
||||
现在，你可以使用新加的空间，按照你的需求调整现有 LV 的大小，或者创建一个新的 LV。
|
||||
|
||||
@ -151,7 +156,8 @@ LVM 的组成结构：
|
||||
```
|
||||
|
||||
|
||||
>寻找逻辑卷的 UUID
|
||||
|
||||
*寻找逻辑卷的 UUID*
|
||||
|
||||
为每个 LV 创建挂载点：
|
||||
|
||||
@ -175,7 +181,8 @@ UUID=e1929239-5087-44b1-9396-53e09db6eb9e /home/backups ext4 defaults 0 0
|
||||
```
|
||||
|
||||
|
||||
>挂载逻辑卷
|
||||
|
||||
*挂载逻辑卷*
|
||||
|
||||
在涉及到 LV 的实际使用时，你还需要按照曾在本系列[第八讲：管理用户和用户组][4]中讲解的那样，为其设置合适的 `ugo+rwx`。
|
||||
|
||||
@ -193,7 +200,7 @@ via: http://www.tecmint.com/manage-and-create-lvm-parition-using-vgcreate-lvcrea
|
||||
|
||||
作者：[Gabriel Cánepa][a]
|
||||
译者：[martin2011qi](https://github.com/martin2011qi)
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
@ -202,5 +209,5 @@ via: http://www.tecmint.com/manage-and-create-lvm-parition-using-vgcreate-lvcrea
|
||||
[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/
|
||||
[3]: https://linux.cn/article-7187-1.html
|
||||
[4]: https://linux.cn/article-7418-1.html
|
||||
[5]: http://www.tecmint.com/create-lvm-storage-in-linux/
|
||||
[5]: https://linux.cn/article-3965-1.html
|
||||
[6]: https://linux.cn/article-7229-1.html
|
||||
@ -0,0 +1,184 @@
|
||||
LFCS 系列第十二讲：如何使用 Linux 的帮助文档和工具
|
||||
==================================================================================
|
||||
|
||||
由于 2016 年 2 月 2 号开始启用了新的 LFCS 考试要求, 我们在 [LFCS 系列][1]系列添加了一些必要的内容。为了考试的需要，我们强烈建议你看一下[LFCE 系列][2]。
|
||||
|
||||
|
||||
|
||||
*LFCS: 了解 Linux 的帮助文档和工具*
|
||||
|
||||
当你习惯了在命令行下进行工作，你会发现 Linux 已经有了许多使用和配置 Linux 系统所需要的文档。
|
||||
|
||||
另一个你必须熟悉命令行帮助工具的理由是，在[LFCS][3] 和 [LFCE][4] 考试中，它们是你唯一能够使用的信息来源，没有互联网也没有百度。你只能依靠你自己和命令行。
|
||||
|
||||
基于上面的理由，在这一章里我们将给你一些建议来可以让你有效的使用这些安装的文档和工具，以帮助你通过**Linux 基金会认证**考试。
|
||||
|
||||
### Linux 帮助手册（man）
|
||||
|
||||
man 手册是 manual 手册的缩写，就是其名字所揭示的那样：一个给定工具的帮助手册。它包含了命令所支持的选项列表（以及解释），有些工具甚至还提供一些使用范例。
|
||||
|
||||
我们用 **man 命令** 跟上你想要了解的工具名称来打开一个帮助手册。例如：
|
||||
|
||||
```
|
||||
# man diff
|
||||
```
|
||||
|
||||
这将打开`diff`的手册页，这个工具将逐行对比文本文件（如你想退出只需要轻轻的点一下 q 键）。
|
||||
|
||||
下面我来比较两个文本文件 `file1` 和 `file2`。这两个文本文件包含了使用同一个 Linux 发行版相同版本安装的两台机器上的的安装包列表。
|
||||
|
||||
输入`diff` 命令它将告诉我们 `file1` 和`file2` 有什么不同:
|
||||
|
||||
```
|
||||
# diff file1 file2
|
||||
```
|
||||
|
||||
|
||||
|
||||
*在Linux中比较两个文本文件*
|
||||
|
||||
`<` 这个符号是说`file2`缺失的行。如果是 `file1`缺失，我们将用 `>` 符号来替代指示。
|
||||
|
||||
另外，**7d6** 意思是说`file1`的第**7**行要删除了才能和`file2`一致（**24d22** 和 **41d38** 也是同样的意思） **65,67d61** 告诉需要删除从第 **65** 行到 **67** 行。我们完成了以上步骤，那么这两个文件将完全一致。
|
||||
|
||||
此外，根据 man 手册说明，你还可以通过 `-y` 选项来以两路的方式显示文件。你可以发现这对于你找到两个文件间的不同根据方便容易。
|
||||
|
||||
```
|
||||
# diff -y file1 file2
|
||||
```
|
||||
|
||||
|
||||
|
||||
*比较并列出两个文件的不同*
|
||||
|
||||
此外，你也可以用`diff`来比较两个二进制文件。如果它们完全一样，`diff` 将什么也不会输出。否则，它将会返回如下信息：“**Binary files X and Y differ**”。
|
||||
|
||||
### –help 选项
|
||||
|
||||
`--help`选项，大多数命令都支持它（并不是所有）， 它可以理解为一个命令的简短帮助手册。尽管它没有提供工具的详细介绍，但是确实是一个能够快速列出程序的所支持的选项的不错的方法。
|
||||
|
||||
例如，
|
||||
|
||||
```
|
||||
# sed --help
|
||||
```
|
||||
|
||||
将显示 sed （流编辑器）的每个支持的选项。
|
||||
|
||||
`sed`命令的一个典型用法是替换文件中的字符。用 `-i` 选项（意思是 “**原地编辑编辑文件**”），你可以编辑一个文件而且并不需要打开它。 如果你想要同时备份一个原始文件，用 `-i` 选项加后缀来创建一个原始文件的副本。
|
||||
|
||||
例如，替换 `lorem.txt` 中的`Lorem` 为 `Tecmint`（忽略大小写），并且创建一个原文件的备份副本，命令如下：
|
||||
|
||||
```
|
||||
# less lorem.txt | grep -i lorem
|
||||
# sed -i.orig 's/Lorem/Tecmint/gI' lorem.txt
|
||||
# less lorem.txt | grep -i lorem
|
||||
# less lorem.txt.orig | grep -i lorem
|
||||
```
|
||||
|
||||
请注意`lorem.txt`文件中`Lorem` 都已经替换为 `Tecmint`，并且原文件 `lorem.txt` 被保存为`lorem.txt.orig`。
|
||||
|
||||
|
||||
|
||||
*替换文件中的文本*
|
||||
|
||||
### /usr/share/doc 内的文档
|
||||
|
||||
这可能是我最喜欢的方法。如果你进入 `/usr/share/doc` 目录，并列出该目录，你可以看到许多以安装在你的 Linux 上的工具为名称的文件夹。
|
||||
|
||||
根据 [文件系统层级标准][5]，这些文件夹包含了许多帮助手册没有的信息，还有一些可以使配置更方便的模板和配置文件。
|
||||
|
||||
例如，让我们来看一下 `squid-3.3.8` （不同发行版的版本可能会不同），这还是一个非常受欢迎的 HTTP 代理和 [squid 缓存服务器][6]。
|
||||
|
||||
让我们用`cd`命令进入目录：
|
||||
|
||||
```
|
||||
# cd /usr/share/doc/squid-3.3.8
|
||||
```
|
||||
|
||||
列出当前文件夹列表：
|
||||
|
||||
```
|
||||
# ls
|
||||
```
|
||||
|
||||
|
||||
|
||||
*使用 ls 列出目录*
|
||||
|
||||
你应该特别注意 `QUICKSTART` 和 `squid.conf.documented`。这些文件分别包含了 Squid 详细文档及其经过详细备注的配置文件。对于别的安装包来说，具体的名字可能不同（有可能是 **QuickRef** 或者**00QUICKSTART**），但意思是一样的。
|
||||
|
||||
对于另外一些安装包，比如 Apache web 服务器，在`/usr/share/doc`目录提供了配置模板，当你配置独立服务器或者虚拟主机的时候会非常有用。
|
||||
|
||||
### GNU 信息文档
|
||||
|
||||
你可以把它看做帮助手册的“开挂版”。它不仅仅提供工具的帮助信息，而且还是超级链接的形式（没错，在命令行中的超级链接），你可以通过箭头按钮从一个章节导航到另外章节，并按下回车按钮来确认。
|
||||
|
||||
一个典型的例子是：
|
||||
|
||||
```
|
||||
# info coreutils
|
||||
```
|
||||
|
||||
因为 coreutils 包含了每个系统中都有的基本文件、shell 和文本处理工具，你自然可以从 coreutils 的 info 文档中得到它们的详细介绍。
|
||||
|
||||
|
||||
|
||||
*Info Coreutils*
|
||||
|
||||
和帮助手册一样，你可以按 q 键退出。
|
||||
|
||||
此外，GNU info 还可以显示标准的帮助手册。 例如：
|
||||
|
||||
```
|
||||
# info tune2fs
|
||||
```
|
||||
|
||||
它将显示 **tune2fs**的帮助手册, 这是一个 ext2/3/4 文件系统管理工具。
|
||||
|
||||
我们现在看到了，让我们来试试怎么用**tune2fs**：
|
||||
|
||||
显示 **/dev/mapper/vg00-vol_backups** 文件系统信息：
|
||||
|
||||
```
|
||||
# tune2fs -l /dev/mapper/vg00-vol_backups
|
||||
```
|
||||
|
||||
修改文件系统标签（修改为 Backups）：
|
||||
|
||||
```
|
||||
# tune2fs -L Backups /dev/mapper/vg00-vol_backups
|
||||
```
|
||||
|
||||
设置文件系统的自检间隔及挂载计数（用`-c` 选项设置挂载计数间隔， 用 `-i` 选项设置自检时间间隔，这里 **d 表示天，w 表示周，m 表示月**)。
|
||||
|
||||
```
|
||||
# tune2fs -c 150 /dev/mapper/vg00-vol_backups # 每 150 次挂载检查一次
|
||||
# tune2fs -i 6w /dev/mapper/vg00-vol_backups # 每 6 周检查一次
|
||||
```
|
||||
|
||||
以上这些内容也可以通过 `--help` 选项找到，或者查看帮助手册。
|
||||
|
||||
### 摘要
|
||||
|
||||
不管你选择哪种方法，知道并且会使用它们在考试中对你是非常有用的。你知道其它的一些方法吗? 欢迎给我们留言。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/explore-linux-installed-help-documentation-and-tools/
|
||||
|
||||
作者：[Gabriel Cánepa][a]
|
||||
译者：[kokialoves](https://github.com/kokialoves)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://www.tecmint.com/author/gacanepa/
|
||||
[1]: https://linux.cn/article-7161-1.html
|
||||
[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/
|
||||
[3]: https://linux.cn/article-7161-1.html
|
||||
[4]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/
|
||||
[5]: https://linux.cn/article-6132-1.html
|
||||
[6]: http://www.tecmint.com/configure-squid-server-in-linux/
|
||||
[7]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
Part 1 - LXD 2.0: LXD 入门
|
||||
LXD 2.0 系列（一）：LXD 入门
|
||||
======================================
|
||||
|
||||
这是 [LXD 2.0 系列介绍文章][1]的第一篇。
|
||||
@ -20,12 +20,11 @@ LXD 最主要的目标就是使用 Linux 容器而不是硬件虚拟化向用户
|
||||
|
||||
LXD 聚焦于系统容器，通常也被称为架构容器。这就是说 LXD 容器实际上如在裸机或虚拟机上运行一般运行了一个完整的 Linux 操作系统。
|
||||
|
||||
这些容器一般基于一个干净的发布镜像并会长时间运行。传统的配置管理工具和部署工具可以如在虚拟机、云和物理机器上一样与 LXD 一起使用。
|
||||
这些容器一般基于一个干净的发布镜像并会长时间运行。传统的配置管理工具和部署工具可以如在虚拟机、云实例和物理机器上一样与 LXD 一起使用。
|
||||
|
||||
相对的， Docker 关注于短期的、无状态的最小容器，这些容器通常并不会升级或者重新配置，而是作为一个整体被替换掉。这就使得 Docker 及类似项目更像是一种软件发布机制，而不是一个机器管理工具。
|
||||
|
||||
这两种模型并不是完全互斥的。你完全可以使用 LXD 为你的用户提供一个完整的 Linux 系统，而他们可以在 LXD 内安装 Docker 来运行他们想要的软件。
|
||||
相对的， Docker 关注于短期的、无状态的、最小化的容器，这些容器通常并不会升级或者重新配置，而是作为一个整体被替换掉。这就使得 Docker 及类似项目更像是一种软件发布机制，而不是一个机器管理工具。
|
||||
|
||||
这两种模型并不是完全互斥的。你完全可以使用 LXD 为你的用户提供一个完整的 Linux 系统，然后他们可以在 LXD 内安装 Docker 来运行他们想要的软件。
|
||||
|
||||
#### 为什么要用 LXD?
|
||||
|
||||
@ -35,56 +34,55 @@ LXD 聚焦于系统容器，通常也被称为架构容器。这就是说 LXD
|
||||
|
||||
我们把 LXD 作为解决这些缺陷的一个很好的机会。作为一个长时间运行的守护进程， LXD 可以绕开 LXC 的许多限制，比如动态资源限制、无法进行容器迁移和高效的在线迁移；同时，它也为创造新的默认体验提供了机会：默认开启安全特性，对用户更加友好。
|
||||
|
||||
|
||||
### LXD 的主要组件
|
||||
|
||||
LXD 是由几个主要组件构成的，这些组件都是 LXD 目录结构、命令行客户端和 API 结构体里下可见的。
|
||||
LXD 是由几个主要组件构成的，这些组件都出现在 LXD 目录结构、命令行客户端和 API 结构体里。
|
||||
|
||||
#### 容器
|
||||
|
||||
LXD 中的容器包括以下及部分：
|
||||
|
||||
- 根文件系统
|
||||
- 根文件系统（rootfs）
|
||||
- 配置选项列表，包括资源限制、环境、安全选项等等
|
||||
- 设备：包括磁盘、unix 字符/块设备、网络接口
|
||||
- 一组继承而来的容器配置文件
|
||||
- 属性（容器架构，暂时的或持久的，容器名）
|
||||
- 运行时状态（当时为了记录检查点、恢复时用到了 CRIU时）
|
||||
- 属性（容器架构、暂时的还是持久的、容器名）
|
||||
- 运行时状态（当用 CRIU 来中断/恢复时）
|
||||
|
||||
#### 快照
|
||||
|
||||
容器快照和容器是一回事，只不过快照是不可修改的，只能被重命名，销毁或者用来恢复系统，但是无论如何都不能被修改。
|
||||
|
||||
值得注意的是，因为我们允许用户保存容器的运行时状态，这就有效的为我们提供了“有状态”的快照的功能。这就是说我们可以使用快照回滚容器的 CPU 和内存。
|
||||
值得注意的是，因为我们允许用户保存容器的运行时状态，这就有效的为我们提供了“有状态”的快照的功能。这就是说我们可以使用快照回滚容器的状态，包括快照当时的 CPU 和内存状态。
|
||||
|
||||
#### 镜像
|
||||
|
||||
LXD 是基于镜像实现的，所有的 LXD 容器都是来自于镜像。容器镜像通常是一些纯净的 Linux 发行版的镜像，类似于你们在虚拟机和云实例上使用的镜像。
|
||||
|
||||
所以就可以「发布」容器：使用容器制作一个镜像并在本地或者远程 LXD 主机上使用。
|
||||
所以可以「发布」一个容器：使用容器制作一个镜像并在本地或者远程 LXD 主机上使用。
|
||||
|
||||
镜像通常使用全部或部分 sha256 哈希码来区分。因为输入长长的哈希码对用户来说不好，所以镜像可以使用几个自身的属性来区分，这就使得用户在镜像商店里方便搜索镜像。别名也可以用来 1 对 1 地把对用户友好的名字映射到某个镜像的哈希码。
|
||||
镜像通常使用全部或部分 sha256 哈希码来区分。因为输入长长的哈希码对用户来说不方便，所以镜像可以使用几个自身的属性来区分，这就使得用户在镜像商店里方便搜索镜像。也可以使用别名来一对一地将一个用户好记的名字映射到某个镜像的哈希码上。
|
||||
|
||||
LXD 安装时已经配置好了三个远程镜像服务器（参见下面的远程一节）：
|
||||
|
||||
- “ubuntu：” 提供稳定版的 Ubuntu 镜像
|
||||
- “ubuntu-daily：” 提供每天构建出来的 Ubuntu
|
||||
- “images：” 社区维护的镜像服务器，提供一系列的 Linux 发布版，使用的是上游 LXC 的模板
|
||||
- “ubuntu”：提供稳定版的 Ubuntu 镜像
|
||||
- “ubuntu-daily”：提供 Ubuntu 的每日构建镜像
|
||||
- “images”： 社区维护的镜像服务器，提供一系列的其它 Linux 发布版，使用的是上游 LXC 的模板
|
||||
|
||||
LXD 守护进程会从镜像上次被使用开始自动缓存远程镜像一段时间（默认是 10 天），超过时限后这些镜像才会失效。
|
||||
|
||||
此外， LXD 还会自动更新远程镜像（除非指明不更新），所以本地的镜像会一直是最新版的。
|
||||
|
||||
|
||||
#### 配置
|
||||
|
||||
配置文件是一种在一处定义容器配置和容器设备，然后应用到一系列容器的方法。
|
||||
配置文件是一种在一个地方定义容器配置和容器设备，然后将其应用到一系列容器的方法。
|
||||
|
||||
一个容器可以被应用多个配置文件。当构建最终容器配置时（即通常的扩展配置），这些配置文件都会按照他们定义顺序被应用到容器上，当有重名的配置时，新的会覆盖掉旧的。然后本地容器设置会在这些基础上应用，覆盖所有来自配置文件的选项。
|
||||
一个容器可以被应用多个配置文件。当构建最终容器配置时（即通常的扩展配置），这些配置文件都会按照他们定义顺序被应用到容器上，当有重名的配置键或设备时，新的会覆盖掉旧的。然后本地容器设置会在这些基础上应用，覆盖所有来自配置文件的选项。
|
||||
|
||||
LXD 自带两种预配置的配置文件：
|
||||
|
||||
- 「 default 」配置是自动应用在所有容器之上，除非用户提供了一系列替代的配置文件。目前这个配置文件只做一件事，为容器定义 eth0 网络设备。
|
||||
- 「 docker” 」配置是一个允许你在容器里运行 Docker 容器的配置文件。它会要求 LXD 加载一些需要的内核模块以支持容器嵌套并创建一些设备入口。
|
||||
- “default”配置是自动应用在所有容器之上，除非用户提供了一系列替代的配置文件。目前这个配置文件只做一件事，为容器定义 eth0 网络设备。
|
||||
- “docker”配置是一个允许你在容器里运行 Docker 容器的配置文件。它会要求 LXD 加载一些需要的内核模块以支持容器嵌套并创建一些设备。
|
||||
|
||||
#### 远程
|
||||
|
||||
@ -92,14 +90,14 @@ LXD 自带两种预配置的配置文件：
|
||||
|
||||
默认情况下，我们的命令行客户端会与下面几个预定义的远程服务器通信：
|
||||
|
||||
- local：（默认的远程服务器，使用 UNIX socket 和本地的 LXD 守护进程通信）
|
||||
- ubuntu：（ Ubuntu 镜像服务器，提供稳定版的 Ubuntu 镜像）
|
||||
- ubuntu-daily：（ Ubuntu 镜像服务器，提供每天构建出来的 Ubuntu ）
|
||||
- images：（ images.linuxcontainers.org 镜像服务器）
|
||||
- local：默认的远程服务器，使用 UNIX socket 和本地的 LXD 守护进程通信
|
||||
- ubuntu：Ubuntu 镜像服务器，提供稳定版的 Ubuntu 镜像
|
||||
- ubuntu-daily：Ubuntu 镜像服务器，提供 Ubuntu 的每日构建版
|
||||
- images：images.linuxcontainers.org 的镜像服务器
|
||||
|
||||
所有这些远程服务器的组合都可以在命令行客户端里使用。
|
||||
|
||||
你也可以添加任意数量的远程 LXD 主机来监听网络。匿名的开放镜像服务器，或者通过认证可以管理远程容器的镜像服务器，都可以添加进来。
|
||||
你也可以添加任意数量的远程 LXD 主机，并配置它们监听网络。匿名的开放镜像服务器，或者通过认证可以管理远程容器的镜像服务器，都可以添加进来。
|
||||
|
||||
正是这种远程机制使得与远程镜像服务器交互及在主机间复制、移动容器成为可能。
|
||||
|
||||
@ -107,30 +105,29 @@ LXD 自带两种预配置的配置文件：
|
||||
|
||||
我们设计 LXD 时的一个核心要求，就是在不修改现代 Linux 发行版的前提下，使容器尽可能的安全。
|
||||
|
||||
LXD 使用的、通过使用 LXC 库实现的主要安全特性有：
|
||||
LXD 通过使用 LXC 库实现的主要安全特性有：
|
||||
|
||||
- 内核名字空间。尤其是用户名字空间，它让容器和系统剩余部分完全分离。LXD 默认使用用户名字空间（和 LXC 相反），并允许用户在需要的时候以容器为单位打开或关闭。
|
||||
- 内核名字空间。尤其是用户名字空间，它让容器和系统剩余部分完全分离。LXD 默认使用用户名字空间（和 LXC 相反），并允许用户在需要的时候以容器为单位关闭（将容器标为“特权的”）。
|
||||
- Seccomp 系统调用。用来隔离潜在危险的系统调用。
|
||||
- AppArmor：对 mount、socket、ptrace 和文件访问提供额外的限制。特别是限制跨容器通信。
|
||||
- AppArmor。对 mount、socket、ptrace 和文件访问提供额外的限制。特别是限制跨容器通信。
|
||||
- Capabilities。阻止容器加载内核模块，修改主机系统时间，等等。
|
||||
- CGroups。限制资源使用，防止对主机的 DoS 攻击。
|
||||
- CGroups。限制资源使用，防止针对主机的 DoS 攻击。
|
||||
|
||||
为了对用户友好，LXD 构建了一个新的配置语言把大部分的这些特性都抽象封装起来，而不是如 LXC 一般直接将这些特性暴露出来。举了例子，一个用户可以告诉 LXD 把主机设备放进容器而不需要手动检查他们的主/次设备号来手动更新 CGroup 策略。
|
||||
|
||||
为了对用户友好 ， LXD 构建了一个新的配置语言把大部分的这些特性都抽象封装起来，而不是如 LXC 一般直接将这些特性暴露出来。举了例子，一个用户可以告诉 LXD 把主机设备放进容器而不需要手动检查他们的主/次设备号来更新 CGroup 策略。
|
||||
|
||||
和 LXD 本身通信是基于使用 TLS 1.2 保护的链路，这些链路只允许使用有限的几个被允许的密钥。当和那些经过系统证书认证之外的主机通信时， LXD 会提示用户验证主机的远程足迹（SSH 方式），然后把足迹缓存起来以供以后使用。
|
||||
和 LXD 本身通信是基于使用 TLS 1.2 保护的链路，只允许使用有限的几个被允许的密钥算法。当和那些经过系统证书认证之外的主机通信时， LXD 会提示用户验证主机的远程指纹（SSH 方式），然后把指纹缓存起来以供以后使用。
|
||||
|
||||
### REST 接口
|
||||
|
||||
LXD 的工作都是通过 REST 接口实现的。在客户端和守护进程之间并没有其他的通讯手段。
|
||||
LXD 的工作都是通过 REST 接口实现的。在客户端和守护进程之间并没有其他的通讯渠道。
|
||||
|
||||
REST 接口可以通过本地的 unix socket 访问，这只需要经过组认证，或者经过 HTTP 套接字使用客户端认证进行通信。
|
||||
REST 接口可以通过本地的 unix socket 访问，这只需要经过用户组认证，或者经过 HTTP 套接字使用客户端认证进行通信。
|
||||
|
||||
REST 接口的结构能够和上文所说的不同的组件匹配，是一种简单、直观的使用方法。
|
||||
|
||||
当需要一种复杂的通信机制时， LXD 将会进行 websocket 协商完成剩余的通信工作。这主要用于交互式终端会话、容器迁移和事件通知。
|
||||
|
||||
LXD 2.0 附带了 1.0 版的稳定 API。虽然我们在 1.0 版 API 添加了额外的特性，但是这不会在 1.0 版 API 的端点里破坏向后兼容性，因为我们会声明额外的 API 扩展使得客户端可以找到新的接口。
|
||||
LXD 2.0 附带了 1.0 版的稳定 API。虽然我们在 1.0 版 API 添加了额外的特性，但是这不会在 1.0 版 API 端点里破坏向后兼容性，因为我们会声明额外的 API 扩展使得客户端可以找到新的接口。
|
||||
|
||||
### 容器规模化
|
||||
|
||||
@ -1,28 +1,28 @@
|
||||
如何使用Awk和正则表达式过滤文本或文件中的字符串
|
||||
awk 系列：如何使用 awk 和正则表达式过滤文本或文件中的字符串
|
||||
=============================================================================
|
||||
|
||||
|
||||
|
||||
当我们在 Unix/Linux 下使用特定的命令从字符串或文件中读取或编辑文本时，我们经常会尝试过滤输出以得到感兴趣的部分。这时正则表达式就派上用场了。
|
||||
当我们在 Unix/Linux 下使用特定的命令从字符串或文件中读取或编辑文本时，我们经常需要过滤输出以得到感兴趣的部分。这时正则表达式就派上用场了。
|
||||
|
||||
### 什么是正则表达式?
|
||||
|
||||
正则表达式可以定义为代表若干个字符序列的字符串。它最重要的功能就是它允许你过滤一条命令或一个文件的输出，编辑文本或配置等文件的一部分。
|
||||
正则表达式可以定义为代表若干个字符序列的字符串。它最重要的功能之一就是它允许你过滤一条命令或一个文件的输出、编辑文本或配置文件的一部分等等。
|
||||
|
||||
### 正则表达式的特点
|
||||
|
||||
正则表达式由以下内容组合而成：
|
||||
|
||||
- 普通的字符，例如空格、下划线、A-Z、a-z、0-9。
|
||||
- 可以扩展为普通字符的元字符，它们包括：
|
||||
- **普通字符**，例如空格、下划线、A-Z、a-z、0-9。
|
||||
- 可以扩展为普通字符的**元字符**，它们包括：
|
||||
- `(.)` 它匹配除了换行符外的任何单个字符。
|
||||
- `(*)` 它匹配零个或多个在其之前的立即字符。
|
||||
- `[ character(s) ]` 它匹配任何由 character(s) 指定的一个字符，你可以使用连字符(-)代表字符区间，例如 [a-f]、[1-5]等。
|
||||
- `(*)` 它匹配零个或多个在其之前紧挨着的字符。
|
||||
- `[ character(s) ]` 它匹配任何由其中的字符/字符集指定的字符，你可以使用连字符(-)代表字符区间，例如 [a-f]、[1-5]等。
|
||||
- `^` 它匹配文件中一行的开头。
|
||||
- `$` 它匹配文件中一行的结尾。
|
||||
- `\` 这是一个转义字符。
|
||||
|
||||
你必须使用类似 awk 这样的文本过滤工具来过滤文本。你还可以把 awk 当作一个用于自身的编程语言。但由于这个指南的适用范围是关于使用 awk 的，我会按照一个简单的命令行过滤工具来介绍它。
|
||||
你必须使用类似 awk 这样的文本过滤工具来过滤文本。你还可以把 awk 自身当作一个编程语言。但由于这个指南的适用范围是关于使用 awk 的，我会按照一个简单的命令行过滤工具来介绍它。
|
||||
|
||||
awk 的一般语法如下：
|
||||
|
||||
@ -30,13 +30,13 @@ awk 的一般语法如下：
|
||||
# awk 'script' filename
|
||||
```
|
||||
|
||||
此处 `'script'` 是一个由 awk 使用并应用于 filename 的命令集合。
|
||||
此处 `'script'` 是一个由 awk 可以理解并应用于 filename 的命令集合。
|
||||
|
||||
它通过读取文件中的给定的一行，复制该行的内容并在该行上执行脚本的方式工作。这个过程会在该文件中的所有行上重复。
|
||||
它通过读取文件中的给定行，复制该行的内容并在该行上执行脚本的方式工作。这个过程会在该文件中的所有行上重复。
|
||||
|
||||
该脚本 `'script'` 中内容的格式是 `'/pattern/ action'`，其中 `pattern` 是一个正则表达式，而 `action` 是当 awk 在该行中找到此模式时应当执行的动作。
|
||||
|
||||
### 如何在 Linux 中使用 Awk 过滤工具
|
||||
### 如何在 Linux 中使用 awk 过滤工具
|
||||
|
||||
在下面的例子中，我们将聚焦于之前讨论过的元字符。
|
||||
|
||||
@ -45,13 +45,14 @@ awk 的一般语法如下：
|
||||
下面的例子打印文件 /etc/hosts 中的所有行，因为没有指定任何的模式。
|
||||
|
||||
```
|
||||
# awk '//{print}'/etc/hosts
|
||||
# awk '//{print}' /etc/hosts
|
||||
```
|
||||
|
||||
|
||||
>Awk 打印文件中的所有行
|
||||
|
||||
#### 结合模式使用 Awk
|
||||
*awk 打印文件中的所有行*
|
||||
|
||||
#### 结合模式使用 awk
|
||||
|
||||
在下面的示例中，指定了模式 `localhost`，因此 awk 将匹配文件 `/etc/hosts` 中有 `localhost` 的那些行。
|
||||
|
||||
@ -60,22 +61,24 @@ awk 的一般语法如下：
|
||||
```
|
||||
|
||||
|
||||
>Awk 打印文件中匹配模式的行
|
||||
|
||||
#### 在 Awk 模式中使用通配符 (.)
|
||||
*awk 打印文件中匹配模式的行*
|
||||
|
||||
#### 在 awk 模式中使用通配符 (.)
|
||||
|
||||
在下面的例子中，符号 `(.)` 将匹配包含 loc、localhost、localnet 的字符串。
|
||||
|
||||
这里的意思是匹配 *** l 一些单个字符 c ***。
|
||||
这里的正则表达式的意思是匹配 **l一个字符c**。
|
||||
|
||||
```
|
||||
# awk '/l.c/{print}' /etc/hosts
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 打印文件中匹配模式的字符串
|
||||
|
||||
#### 在 Awk 模式中使用字符 (*)
|
||||
*使用 awk 打印文件中匹配模式的字符串*
|
||||
|
||||
#### 在 awk 模式中使用字符 (*)
|
||||
|
||||
在下面的例子中，将匹配包含 localhost、localnet、lines, capable 的字符串。
|
||||
|
||||
@ -84,7 +87,8 @@ awk 的一般语法如下：
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 匹配文件中的字符串
|
||||
|
||||
*使用 awk 匹配文件中的字符串*
|
||||
|
||||
你可能也意识到 `(*)` 将会尝试匹配它可能检测到的最长的匹配。
|
||||
|
||||
@ -112,7 +116,7 @@ this is tecmint, where you get the best good tutorials, how tos, guides, tecmint
|
||||
this is tecmint, where you get the best good tutorials, how to's, guides, tecmint
|
||||
```
|
||||
|
||||
#### 结合集合 [ character(s) ] 使用 Awk
|
||||
#### 结合集合 [ character(s) ] 使用 awk
|
||||
|
||||
以集合 [al1] 为例，awk 将匹配文件 /etc/hosts 中所有包含字符 a 或 l 或 1 的字符串。
|
||||
|
||||
@ -121,7 +125,8 @@ this is tecmint, where you get the best good tutorials, how to's, guides, tecmin
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 打印文件中匹配的字符
|
||||
|
||||
*使用 awk 打印文件中匹配的字符*
|
||||
|
||||
下一个例子匹配以 `K` 或 `k` 开始头，后面跟着一个 `T` 的字符串：
|
||||
|
||||
@ -130,7 +135,8 @@ this is tecmint, where you get the best good tutorials, how to's, guides, tecmin
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 打印文件中匹配的字符
|
||||
|
||||
*使用 awk 打印文件中匹配的字符*
|
||||
|
||||
#### 以范围的方式指定字符
|
||||
|
||||
@ -149,11 +155,12 @@ awk 所能理解的字符：
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 打印文件中匹配的数字
|
||||
|
||||
*使用 awk 打印文件中匹配的数字*
|
||||
|
||||
在上面的例子中，文件 /etc/hosts 中的所有行都至少包含一个单独的数字 [0-9]。
|
||||
|
||||
#### 结合元字符 (\^) 使用 Awk
|
||||
#### 结合元字符 (\^) 使用 awk
|
||||
|
||||
在下面的例子中，它匹配所有以给定模式开头的行：
|
||||
|
||||
@ -163,9 +170,10 @@ awk 所能理解的字符：
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 打印与模式匹配的行
|
||||
|
||||
#### 结合元字符 ($) 使用 Awk
|
||||
*使用 awk 打印与模式匹配的行*
|
||||
|
||||
#### 结合元字符 ($) 使用 awk
|
||||
|
||||
它将匹配所有以给定模式结尾的行：
|
||||
|
||||
@ -176,9 +184,10 @@ awk 所能理解的字符：
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 打印与模式匹配的字符串
|
||||
|
||||
#### 结合转义字符 (\\) 使用 Awk
|
||||
*使用 awk 打印与模式匹配的字符串*
|
||||
|
||||
#### 结合转义字符 (\\) 使用 awk
|
||||
|
||||
它允许你将该转义字符后面的字符作为文字，即理解为其字面的意思。
|
||||
|
||||
@ -193,11 +202,12 @@ awk 所能理解的字符：
|
||||
```
|
||||
|
||||
|
||||
>结合转义字符使用 Awk
|
||||
|
||||
*结合转义字符使用 awk*
|
||||
|
||||
### 总结
|
||||
|
||||
以上内容并不是 Awk 命令用做过滤工具的全部，上述的示例均是 awk 的基础操作。在下面的章节中，我将进一步介绍如何使用 awk 的高级功能。感谢您的阅读，请在评论区贴出您的评论。
|
||||
以上内容并不是 awk 命令用做过滤工具的全部，上述的示例均是 awk 的基础操作。在下面的章节中，我将进一步介绍如何使用 awk 的高级功能。感谢您的阅读，请在评论区贴出您的评论。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -205,7 +215,7 @@ via: http://www.tecmint.com/use-linux-awk-command-to-filter-text-string-in-files
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[wwy-hust](https://github.com/wwy-hust)
|
||||
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
|
||||
|
||||
@ -1,18 +1,19 @@
|
||||
如何使用 Awk 输出文本中的字段和列
|
||||
awk 系列：如何使用 awk 输出文本中的字段和列
|
||||
======================================================
|
||||
|
||||
在 Awk 系列的这一节中，我们将看到 Awk 最重要的特性之一，字段编辑。
|
||||
在 Awk 系列的这一节中，我们将看到 awk 最重要的特性之一，字段编辑。
|
||||
|
||||
需要知道的是，Awk 能够自动将输入的行，分隔为若干字段。每一个字段就是一组字符，它们和其他的字段由一个内部字段分隔符分隔开来。
|
||||
首先我们要知道，Awk 能够自动将输入的行，分隔为若干字段。每一个字段就是一组字符，它们和其他的字段由一个内部字段分隔符分隔开来。
|
||||
|
||||
|
||||
>Awk Print Fields and Columns
|
||||
|
||||
如果你熟悉 Unix/Linux 或者使用 [bash 脚本][1]编过程，那么你应该知道什么是内部字段分隔符（IFS）变量。Awk 中默认的 IFS 是制表符和空格。
|
||||
*Awk 输出字段和列*
|
||||
|
||||
Awk 中的字段分隔符的工作流程如下：当读到一行输入时，将它按照指定的 IFS 分割为不同字段，第一组字符就是字段一，可以通过 $1 来访问，第二组字符就是字段二，可以通过 $2 来访问，第三组字符就是字段三，可以通过 $3 来访问，以此类推，直到最后一组字符。
|
||||
如果你熟悉 Unix/Linux 或者懂得 [bash shell 编程][1]，那么你应该知道什么是内部字段分隔符（IFS）变量。awk 中默认的 IFS 是制表符和空格。
|
||||
|
||||
为了更好地理解 Awk 的字段编辑，让我们看一个下面的例子：
|
||||
awk 中的字段分隔符的工作原理如下：当读到一行输入时，将它按照指定的 IFS 分割为不同字段，第一组字符就是字段一，可以通过 $1 来访问，第二组字符就是字段二，可以通过 $2 来访问，第三组字符就是字段三，可以通过 $3 来访问，以此类推，直到最后一组字符。
|
||||
|
||||
为了更好地理解 awk 的字段编辑，让我们看一个下面的例子：
|
||||
|
||||
**例 1**：我创建了一个名为 tecmintinfo.txt 的文本文件。
|
||||
|
||||
@ -22,7 +23,8 @@ Awk 中的字段分隔符的工作流程如下：当读到一行输入时，将
|
||||
```
|
||||
|
||||
|
||||
>在 Linux 上创建一个文件
|
||||
|
||||
*在 Linux 上创建一个文件*
|
||||
|
||||
然后在命令行中，我试着使用下面的命令从文本 tecmintinfo.txt 中输出第一个，第二个，以及第三个字段。
|
||||
|
||||
@ -47,15 +49,16 @@ $ awk '//{print $1, $2, $3; }' tecmintinfo.txt
|
||||
TecMint.com is the
|
||||
```
|
||||
|
||||
需要记住而且非常重要的是，`($)` 在 Awk 和在 shell 脚本中的使用是截然不同的！
|
||||
需要记住而且非常重要的是，`($)` 在 awk 和在 shell 脚本中的使用是截然不同的！
|
||||
|
||||
在 shell 脚本中，`($)` 被用来获取变量的值。而在 Awk 中，`($)` 只有在获取字段的值时才会用到，不能用于获取变量的值。
|
||||
在 shell 脚本中，`($)` 被用来获取变量的值。而在 awk 中，`($)` 只有在获取字段的值时才会用到，不能用于获取变量的值。
|
||||
|
||||
**例 2**：让我们再看一个例子，用到了一个名为 my_shoping.list 的包含多行的文件。
|
||||
|
||||
```
|
||||
No Item_Name Unit_Price Quantity Price
|
||||
1 Mouse #20,000 1 #20,000
|
||||
2 Monitor #500,000 1 #500,000
|
||||
2 Monitor #500,000 1 #500,000
|
||||
3 RAM_Chips #150,000 2 #300,000
|
||||
4 Ethernet_Cables #30,000 4 #120,000
|
||||
```
|
||||
@ -72,7 +75,7 @@ RAM_Chips #150,000
|
||||
Ethernet_Cables #30,000
|
||||
```
|
||||
|
||||
可以看到上面的输出不够清晰，Awk 还有一个 `printf` 的命令，可以帮助你将输出格式化。
|
||||
可以看到上面的输出不够清晰，awk 还有一个 `printf` 的命令，可以帮助你将输出格式化。
|
||||
|
||||
使用 `printf` 来格式化 Item_Name 和 Unit_Price 的输出：
|
||||
|
||||
@ -88,7 +91,7 @@ Ethernet_Cables #30,000
|
||||
|
||||
### 总结
|
||||
|
||||
使用 Awk 过滤文本或字符串时，字段编辑的功能是非常重要的。它能够帮助你从一个表的数据中得到特定的列。一定要记住的是，Awk 中 `($)` 操作符的用法与其在 shell 脚本中的用法是不同的！
|
||||
使用 awk 过滤文本或字符串时，字段编辑的功能是非常重要的。它能够帮助你从一个表的数据中得到特定的列。一定要记住的是，awk 中 `($)` 操作符的用法与其在 shell 脚本中的用法是不同的！
|
||||
|
||||
希望这篇文章对您有所帮助。如有任何疑问，可以在评论区域发表评论。
|
||||
|
||||
@ -97,8 +100,8 @@ Ethernet_Cables #30,000
|
||||
via: http://www.tecmint.com/awk-print-fields-columns-with-space-separator/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[Cathon](https://github.com/Cathon)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
译者：[Cathon](https://github.com/Cathon)，[ictlyh](https://github.com/ictlyh)
|
||||
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
|
||||
|
||||
@ -1,11 +1,11 @@
|
||||
如何使用 Awk 来筛选文本或字符串
|
||||
awk 系列：如何使用 awk 按模式筛选文本或字符串
|
||||
=========================================================================
|
||||
|
||||
|
||||
|
||||
作为 Awk 命令系列的第三部分，这次我们将看一看如何基于用户定义的特定模式来筛选文本或字符串。
|
||||
作为 awk 命令系列的第三部分，这次我们将看一看如何基于用户定义的特定模式来筛选文本或字符串。
|
||||
|
||||
在筛选文本时，有时你可能想根据某个给定的条件或使用一个特定的可被匹配的模式，去标记某个文件或数行字符串中的某几行。使用 Awk 来完成这个任务是非常容易的，这也正是 Awk 中可能对你有所帮助的几个特色之一。
|
||||
在筛选文本时，有时你可能想根据某个给定的条件或使用一个可被匹配的特定模式，去标记某个文件或数行字符串中的某几行。使用 awk 来完成这个任务是非常容易的，这也正是 awk 中可能对你有所帮助的几个功能之一。
|
||||
|
||||
让我们看一看下面这个例子，比方说你有一个写有你想要购买的食物的购物清单，其名称为 food_prices.list，它所含有的食物名称及相应的价格如下所示：
|
||||
|
||||
@ -28,9 +28,10 @@ $ awk '/ *\$[2-9]\.[0-9][0-9] */ { print $1, $2, $3, $4, "*" ; } / *\$[0-1]\.[0-
|
||||
```
|
||||
|
||||
|
||||
>打印出单价大于 $2 的项目
|
||||
|
||||
从上面的输出你可以看到在含有 芒果(mangoes) 和 菠萝(pineapples) 的那行末尾都已经有了一个 `(*)` 标记。假如你检查它们的单价，你可以看到它们的单价的确超过了 $2 。
|
||||
*打印出单价大于 $2 的项目*
|
||||
|
||||
从上面的输出你可以看到在含有 芒果（mangoes） 和菠萝（pineapples）的那行末尾都已经有了一个 `(*)` 标记。假如你检查它们的单价，你可以看到它们的单价的确超过了 $2 。
|
||||
|
||||
在这个例子中，我们已经使用了两个模式：
|
||||
|
||||
@ -39,33 +40,35 @@ $ awk '/ *\$[2-9]\.[0-9][0-9] */ { print $1, $2, $3, $4, "*" ; } / *\$[0-1]\.[0-
|
||||
|
||||
上面的命令具体做了什么呢？这个文件有四个字段，当模式一匹配到含有食物单价大于 $2 的行时，它便会输出所有的四个字段并在该行末尾加上一个 `(*)` 符号来作为标记。
|
||||
|
||||
第二个模式只是简单地输出其他含有食物单价小于 $2 的行，因为它们出现在输入文件 food_prices.list 中。
|
||||
第二个模式只是简单地输出其他含有食物单价小于 $2 的行，按照它们出现在输入文件 food_prices.list 中的样子。
|
||||
|
||||
这样你就可以使用模式来筛选出那些价格超过 $2 的食物项目，尽管上面的输出还有些问题，带有 `(*)` 符号的那些行并没有像其他行那样被格式化输出，这使得输出显得不够清晰。
|
||||
|
||||
我们在 Awk 系列的第二部分中也看到了同样的问题，但我们可以使用下面的两种方式来解决：
|
||||
我们在 awk 系列的第二部分中也看到了同样的问题，但我们可以使用下面的两种方式来解决：
|
||||
|
||||
1. 可以像下面这样使用 printf 命令，但这样使用又长又无聊：
|
||||
1、可以像下面这样使用 printf 命令，但这样使用又长又无聊：
|
||||
|
||||
```
|
||||
$ awk '/ *\$[2-9]\.[0-9][0-9] */ { printf "%-10s %-10s %-10s %-10s\n", $1, $2, $3, $4 "*" ; } / *\$[0-1]\.[0-9][0-9] */ { printf "%-10s %-10s %-10s %-10s\n", $1, $2, $3, $4; }' food_prices.list
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 和 Printf 来筛选和输出项目
|
||||
|
||||
2. 使用 `$0` 字段。Awk 使用变量 **0** 来存储整个输入行。对于上面的问题，这种方式非常方便，并且它还简单、快速：
|
||||
*使用 Awk 和 Printf 来筛选和输出项目*
|
||||
|
||||
2、 使用 `$0` 字段。Awk 使用变量 **0** 来存储整个输入行。对于上面的问题，这种方式非常方便，并且它还简单、快速：
|
||||
|
||||
```
|
||||
$ awk '/ *\$[2-9]\.[0-9][0-9] */ { print $0 "*" ; } / *\$[0-1]\.[0-9][0-9] */ { print ; }' food_prices.list
|
||||
```
|
||||
|
||||
|
||||
>使用 Awk 和变量来筛选和输出项目
|
||||
|
||||
*使用 Awk 和变量来筛选和输出项目*
|
||||
|
||||
### 结论
|
||||
|
||||
这就是全部内容了，使用 Awk 命令你便可以通过几种简单的方法去利用模式匹配来筛选文本，帮助你在一个文件中对文本或字符串的某些行做标记。
|
||||
这就是全部内容了，使用 awk 命令你便可以通过几种简单的方法去利用模式匹配来筛选文本，帮助你在一个文件中对文本或字符串的某些行做标记。
|
||||
|
||||
希望这篇文章对你有所帮助。记得阅读这个系列的下一部分，我们将关注在 awk 工具中使用比较运算符。
|
||||
|
||||
@ -75,7 +78,7 @@ via: http://www.tecmint.com/awk-filter-text-or-string-using-patterns/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[FSSlc](https://github.com/FSSlc)
|
||||
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
|
||||
|
||||
@ -1,15 +1,15 @@
|
||||
在 Linux 下如何使用 Awk 比较操作符
|
||||
awk 系列：如何使用 awk 比较操作符
|
||||
===================================================
|
||||
|
||||
|
||||
|
||||
对于 Awk 命令的用户来说，处理一行文本中的数字或者字符串时，使用比较运算符来过滤文本和字符串是十分方便的。
|
||||
对于 使用 awk 命令的用户来说，处理一行文本中的数字或者字符串时，使用比较运算符来过滤文本和字符串是十分方便的。
|
||||
|
||||
在 Awk 系列的此部分中，我们将探讨一下如何使用比较运算符来过滤文本或者字符串。如果你是程序员，那么你应该已经熟悉比较运算符；对于其它人，下面的部分将介绍比较运算符。
|
||||
在 awk 系列的此部分中，我们将探讨一下如何使用比较运算符来过滤文本或者字符串。如果你是程序员，那么你应该已经熟悉了比较运算符；对于其它人，下面的部分将介绍比较运算符。
|
||||
|
||||
### Awk 中的比较运算符是什么？
|
||||
### awk 中的比较运算符是什么？
|
||||
|
||||
Awk 中的比较运算符用于比较字符串和或者数值，包括以下类型：
|
||||
awk 中的比较运算符用于比较字符串和或者数值，包括以下类型：
|
||||
|
||||
- `>` – 大于
|
||||
- `<` – 小于
|
||||
@ -17,12 +17,12 @@ Awk 中的比较运算符用于比较字符串和或者数值，包括以下类
|
||||
- `<=` – 小于等于
|
||||
- `==` – 等于
|
||||
- `!=` – 不等于
|
||||
- `some_value ~ / pattern/` – 如果some_value匹配模式pattern，则返回true
|
||||
- `some_value !~ / pattern/` – 如果some_value不匹配模式pattern，则返回true
|
||||
- `some_value ~ / pattern/` – 如果 some_value 匹配模式 pattern，则返回 true
|
||||
- `some_value !~ / pattern/` – 如果 some_value 不匹配模式 pattern，则返回 true
|
||||
|
||||
现在我们通过例子来熟悉 Awk 中各种不同的比较运算符。
|
||||
现在我们通过例子来熟悉 awk 中各种不同的比较运算符。
|
||||
|
||||
在这个例子中，我们有一个文件名为 food_list.txt 的文件，里面包括不同食物的购买列表。我想给食物数量小于或等于30的物品所在行的后面加上`(**)`
|
||||
在这个例子中，我们有一个文件名为 food_list.txt 的文件，里面包括不同食物的购买列表。我想给食物数量小于或等于 30 的物品所在行的后面加上`(**)`
|
||||
|
||||
```
|
||||
File – food_list.txt
|
||||
@ -38,7 +38,7 @@ No Item_Name Quantity Price
|
||||
Awk 中使用比较运算符的通用语法如下：
|
||||
|
||||
```
|
||||
# expression { actions; }
|
||||
# 表达式 { 动作; }
|
||||
```
|
||||
|
||||
为了实现刚才的目的，执行下面的命令：
|
||||
@ -57,8 +57,8 @@ No Item_Name` Quantity Price
|
||||
|
||||
在刚才的例子中，发生如下两件重要的事情：
|
||||
|
||||
- 第一个表达式 `{ action ; }` 组合， `$3 <= 30 { printf “%s\t%s\n”, $0,”**” ; }` 打印出数量小于等于30的行，并且在后面增加`(**)`。物品的数量是通过 `$3`这个域变量获得的。
|
||||
- 第二个表达式 `{ action ; }` 组合, `$3 > 30 { print $0 ;}` 原样输出数量小于等于 `30` 的行。
|
||||
- 第一个“表达式 {动作;}”组合中， `$3 <= 30 { printf “%s\t%s\n”, $0,”**” ; }` 打印出数量小于等于30的行，并且在后面增加`(**)`。物品的数量是通过 `$3` 这个域变量获得的。
|
||||
- 第二个“表达式 {动作;}”组合中， `$3 > 30 { print $0 ;}` 原样输出数量小于等于 `30` 的行。
|
||||
|
||||
再举一个例子：
|
||||
|
||||
@ -78,9 +78,9 @@ No Item_Name Quantity Price
|
||||
|
||||
### 总结
|
||||
|
||||
这是一篇对 Awk 中的比较运算符介绍性的指引，因此你需要尝试其他选项，发现更多使用方法。
|
||||
这是一篇对 awk 中的比较运算符介绍性的指引，因此你需要尝试其他选项，发现更多使用方法。
|
||||
|
||||
如果你遇到或者想到任何问题，请在下面评论区留下评论。请记得阅读 Awk 系列下一部分的文章，那里我将介绍组合表达式。
|
||||
如果你遇到或者想到任何问题，请在下面评论区留下评论。请记得阅读 awk 系列下一部分的文章，那里我将介绍组合表达式。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -88,7 +88,7 @@ via: http://www.tecmint.com/comparison-operators-in-awk/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[chunyang-wen](https://github.com/chunyang-wen)
|
||||
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
|
||||
|
||||
@ -1,31 +1,31 @@
|
||||
如何使用 Awk 复合表达式
|
||||
awk 系列：如何使用 awk 复合表达式
|
||||
====================================================
|
||||
|
||||
|
||||
|
||||
一直以来在查对条件是否匹配时，我们寻求的都是简单的表达式。那如果你想用超过一个表达式，来查对特定的条件呢？
|
||||
一直以来在查对条件是否匹配时，我们使用的都是简单的表达式。那如果你想用超过一个表达式来查对特定的条件呢？
|
||||
|
||||
本文，我们将看看如何在过滤文本和字符串时，结合多个表达式，即复合表达式，用以查对条件。
|
||||
|
||||
Awk 的复合表达式可由表示`与`的组合操作符 `&&` 和表示`或`的 `||` 构成。
|
||||
awk 的复合表达式可由表示“与”的组合操作符 `&&` 和表示“或”的 `||` 构成。
|
||||
|
||||
复合表达式的常规写法如下：
|
||||
|
||||
```
|
||||
( first_expression ) && ( second_expression )
|
||||
( 第一个表达式 ) && ( 第二个表达式 )
|
||||
```
|
||||
|
||||
为了保证整个表达式的正确，在这里必须确保 `first_expression` 和 `second_expression` 是正确的。
|
||||
这里只有当“第一个表达式” 和“第二个表达式”都是真值时整个表达式才为真。
|
||||
|
||||
```
|
||||
( first_expression ) || ( second_expression)
|
||||
( 第一个表达式 ) || ( 第二个表达式)
|
||||
```
|
||||
|
||||
为了保证整个表达式的正确，在这里必须确保 `first_expression` 或 `second_expression` 是正确的。
|
||||
这里只要“第一个表达式” 为真或“第二个表达式”为真，整个表达式就为真。
|
||||
|
||||
**注意**：切记要加括号。
|
||||
|
||||
表达式可以由比较操作符构成，具体可查看 awk 系列的第四部分。
|
||||
表达式可以由比较操作符构成，具体可查看[ awk 系列的第四节][1]。
|
||||
|
||||
现在让我们通过一个例子来加深理解：
|
||||
|
||||
@ -43,7 +43,7 @@ No Name Price Type
|
||||
7 Nano_Prowler_Mini_Drone $36.99 Tech
|
||||
```
|
||||
|
||||
我们只想打印出价格超过 $20 的物品，并在其中种类为 “Tech” 的物品的行末用 (**) 打上标记。
|
||||
我们只想打印出价格超过 $20 且其种类为 “Tech” 的物品，在其行末用 (*) 打上标记。
|
||||
|
||||
我们将要执行以下命令。
|
||||
|
||||
@ -56,13 +56,13 @@ No Name Price Type
|
||||
|
||||
此例，在复合表达式中我们使用了两个表达式：
|
||||
|
||||
- 表达式 1：`($3 ~ /^\$[2-9][0-9]*\.[0-9][0-9]$/)` ；查找交易价格超过 `$20` 的行，即只有当 `$3` 也就是价格满足 `/^\$[2-9][0-9]*\.[0-9][0-9]$/` 时值才为 true。
|
||||
- 表达式 2：`($4 == “Tech”)` ；查找是否有种类为 “`Tech`”的交易，即只有当 `$4` 等于 “`Tech`” 时值才为 true。
|
||||
切记，只有当 `&&` 操作符的两端状态，也就是两个表达式都是 true 的情况下，这一行才会被打上 `(**)` 标志。
|
||||
- 表达式 1：`($3 ~ /^\$[2-9][0-9]*\.[0-9][0-9]$/)` ；查找交易价格超过 `$20` 的行，即只有当 `$3` 也就是价格满足 `/^\$[2-9][0-9]*\.[0-9][0-9]$/` 时值才为真值。
|
||||
- 表达式 2：`($4 == “Tech”)` ；查找是否有种类为 “`Tech`”的交易，即只有当 `$4` 等于 “`Tech`” 时值才为真值。
|
||||
切记，只有当 `&&` 操作符的两端状态，也就是两个表达式都是真值的情况下，这一行才会被打上 `(*)` 标志。
|
||||
|
||||
### 总结
|
||||
|
||||
有些时候为了匹配你的真实想法，就不得不用到复合表达式。当你掌握了比较和复合表达式操作符的用法之后，在难的文本或字符串过滤条件也能轻松解决。
|
||||
有些时候为了真正符合你的需求，就不得不用到复合表达式。当你掌握了比较和复合表达式操作符的用法之后，复杂的文本或字符串过滤条件也能轻松解决。
|
||||
|
||||
希望本向导对你有所帮助，如果你有任何问题或者补充，可以在下方发表评论，你的问题将会得到相应的解释。
|
||||
|
||||
@ -71,9 +71,10 @@ No Name Price Type
|
||||
via: http://www.tecmint.com/combine-multiple-expressions-in-awk/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
译者：[martin2011qi](https://github.com/martin2011qi)
|
||||
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]: http://www.tecmint.com/author/aaronkili/
|
||||
[1]: https://linux.cn/article-7602-1.html
|
||||
@ -1,13 +1,13 @@
|
||||
|
||||
如何使用AWK的‘next’命令
|
||||
awk 系列：如何使用 awk 的 ‘next’ 命令
|
||||
=============================================
|
||||
|
||||
|
||||
|
||||
在Awk 系列的第六章, 我们来看一下`next`命令 ，它告诉 Awk 跳过你所提供的表达式而是读取下一个输入行.
|
||||
`next` 命令帮助你阻止运行多余的步骤.
|
||||
在 awk 系列的第六节，我们来看一下`next`命令 ，它告诉 awk 跳过你所提供的所有剩下的模式和表达式，直接处理下一个输入行。
|
||||
|
||||
要明白它是如何工作的, 让我们来分析一下food_list.txt它看起来像这样 :
|
||||
`next` 命令帮助你阻止运行命令执行过程中多余的步骤。
|
||||
|
||||
要明白它是如何工作的, 让我们来分析一下 food_list.txt 它看起来像这样：
|
||||
|
||||
```
|
||||
Food List Items
|
||||
@ -20,7 +20,7 @@ No Item_Name Price Quantity
|
||||
6 Bananas $3.45 30
|
||||
```
|
||||
|
||||
运行下面的命令，它将在每个食物数量小于或者等于20的行后面标一个星号:
|
||||
运行下面的命令，它将在每个食物数量小于或者等于 20 的行后面标一个星号:
|
||||
|
||||
```
|
||||
# awk '$4 <= 20 { printf "%s\t%s\n", $0,"*" ; } $4 > 20 { print $0 ;} ' food_list.txt
|
||||
@ -36,14 +36,14 @@ No Item_Name Price Quantity
|
||||
|
||||
上面的命令实际运行如下:
|
||||
|
||||
- 首先, 它用`$4 <= 20`表达式检查每个输入行的第四列是否小于或者等于20，如果满足条件, 它将在末尾打一个星号 `(*)` .
|
||||
- 接着, 它用`$4 > 20`表达式检查每个输入行的第四列是否大于20，如果满足条件，显示出来.
|
||||
- 首先，它用`$4 <= 20`表达式检查每个输入行的第四列（数量（Quantity））是否小于或者等于 20，如果满足条件，它将在末尾打一个星号 `(*)`。
|
||||
- 接着，它用`$4 > 20`表达式检查每个输入行的第四列是否大于20，如果满足条件，显示出来。
|
||||
|
||||
但是这里有一个问题, 当第一个表达式用`{ printf "%s\t%s\n", $0,"**" ; }`命令进行标注的时候在同样的步骤第二个表达式也进行了判断这样就浪费了时间.
|
||||
|
||||
因此当我们已经用第一个表达式打印标志行的时候就不在需要用第二个表达式`$4 > 20`再次打印.
|
||||
因此当我们已经用第一个表达式打印标志行的时候就不再需要用第二个表达式`$4 > 20`再次打印。
|
||||
|
||||
要处理这个问题, 我们需要用到`next` 命令:
|
||||
要处理这个问题, 我们需要用到`next` 命令：
|
||||
|
||||
```
|
||||
# awk '$4 <= 20 { printf "%s\t%s\n", $0,"*" ; next; } $4 > 20 { print $0 ;} ' food_list.txt
|
||||
@ -57,11 +57,11 @@ No Item_Name Price Quantity
|
||||
6 Bananas $3.45 30
|
||||
```
|
||||
|
||||
当输入行用`$4 <= 20` `{ printf "%s\t%s\n", $0,"*" ; next ; }`命令打印以后,`next`命令 将跳过第二个`$4 > 20` `{ print $0 ;}`表达式, 继续判断下一个输入行,而不是浪费时间继续判断一下是不是当前输入行还大于20.
|
||||
当输入行用`$4 <= 20` `{ printf "%s\t%s\n", $0,"*" ; next ; }`命令打印以后，`next`命令将跳过第二个`$4 > 20` `{ print $0 ;}`表达式，继续判断下一个输入行，而不是浪费时间继续判断一下是不是当前输入行还大于 20。
|
||||
|
||||
next命令在编写高效的命令脚本时候是非常重要的, 它可以很大的提高脚本速度. 下面我们准备来学习Awk的下一个系列了.
|
||||
`next`命令在编写高效的命令脚本时候是非常重要的，它可以提高脚本速度。本系列的下一部分我们将来学习如何使用 awk 来处理标准输入（STDIN）。
|
||||
|
||||
希望这篇文章对你有帮助,你可以给我们留言.
|
||||
希望这篇文章对你有帮助，你可以给我们留言。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -69,7 +69,7 @@ via: http://www.tecmint.com/use-next-command-with-awk-in-linux/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[kokialoves](https://github.com/kokialoves)
|
||||
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
|
||||
|
||||
@ -0,0 +1,75 @@
|
||||
awk 系列：awk 怎么从标准输入（STDIN）读取输入
|
||||
============================================
|
||||
|
||||
|
||||
|
||||
在 awk 系列的前几节，我们看到大多数操作都是从一个文件或多个文件读取输入，或者你想要把标准输入作为 awk 的输入。
|
||||
|
||||
在 awk 系列的第七节中，我们将会看到几个例子，你可以筛选其他命令的输出代替从一个文件读取输入作为 awk 的输入。
|
||||
|
||||
我们首先从使用 [dir 命令][1]开始，它类似于 [ls 命令][2]，在第一个例子下面，我们使用 `dir -l` 命令的输出作为 awk 命令的输入，这样就可以打印出文件拥有者的用户名，所属组组名以及在当前路径下他／她拥有的文件。
|
||||
|
||||
```
|
||||
# dir -l | awk '{print $3, $4, $9;}'
|
||||
```
|
||||
|
||||
|
||||
|
||||
*列出当前路径下的用户文件*
|
||||
|
||||
|
||||
再来看另一个例子，我们[使用 awk 表达式][3] ，在这里，我们想要在 awk 命令里使用一个表达式筛选出字符串来打印出属于 root 用户的文件。命令如下：
|
||||
|
||||
```
|
||||
# dir -l | awk '$3=="root" {print $1,$3,$4, $9;} '
|
||||
```
|
||||
|
||||
|
||||
|
||||
*列出 root 用户的文件*
|
||||
|
||||
上面的命令包含了 `(==)` 来进行比较操作，这帮助我们在当前路径下筛选出 root 用户的文件。这是通过使用 `$3=="root"` 表达式实现的。
|
||||
|
||||
让我们再看另一个例子，我们使用一个 [awk 比较运算符][4] 来匹配一个确定的字符串。
|
||||
|
||||
这里，我们使用了 [cat 命令][5] 来浏览文件名为 tecmint_deals.txt 的文件内容，并且我们想要仅仅查看有字符串 Tech 的部分，所以我们会运行下列命令：
|
||||
|
||||
```
|
||||
# cat tecmint_deals.txt
|
||||
# cat tecmint_deals.txt | awk '$4 ~ /tech/{print}'
|
||||
# cat tecmint_deals.txt | awk '$4 ~ /Tech/{print}'
|
||||
```
|
||||
|
||||
|
||||
|
||||
*用 Awk 比较运算符匹配字符串*
|
||||
|
||||
在上面的例子中，我们已经用了参数为 `~ /匹配字符/` 的比较操作，但是上面的两个命令给我们展示了一些很重要的问题。
|
||||
|
||||
当你运行带有 tech 字符串的命令时终端没有输出，因为在文件中没有 tech 这种字符串，但是运行带有 Tech 字符串的命令，你却会得到包含 Tech 的输出。
|
||||
|
||||
所以你应该在进行这种比较操作的时候时刻注意这种问题，正如我们在上面看到的那样，awk 对大小写很敏感。
|
||||
|
||||
你总是可以使用另一个命令的输出作为 awk 命令的输入来代替从一个文件中读取输入，这就像我们在上面看到的那样简单。
|
||||
|
||||
希望这些例子足够简单到可以使你理解 awk 的用法，如果你有任何问题，你可以在下面的评论区提问，记得查看 awk 系列接下来的章节内容，我们将关注 awk 的一些功能，比如变量，数字表达式以及赋值运算符。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/read-awk-input-from-stdin-in-linux/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[vim-kakali](https://github.com/vim-kakali)
|
||||
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]: http://www.tecmint.com/author/aaronkili/
|
||||
[1]: http://www.tecmint.com/linux-dir-command-usage-with-examples/
|
||||
[2]: http://www.tecmint.com/15-basic-ls-command-examples-in-linux/
|
||||
[3]: https://linux.cn/article-7599-1.html
|
||||
[4]: https://linux.cn/article-7602-1.html
|
||||
[5]: http://www.tecmint.com/13-basic-cat-command-examples-in-linux/
|
||||
|
||||
|
||||
|
||||
@ -1,47 +0,0 @@
|
||||
Linus Torvalds Talks IoT, Smart Devices, Security Concerns, and More[video]
|
||||
===========================================================================
|
||||
|
||||
|
||||
>Dirk Hohndel interviews Linus Torvalds at ELC.
|
||||
|
||||
For the first time in the 11-year history of the [Embedded Linux Conference (ELC)][0], held in San Diego, April 4-6, the keynotes included a discussion with Linus Torvalds. The creator and lead overseer of the Linux kernel, and “the reason we are all here,” in the words of his interviewer, Intel Chief Linux and Open Source Technologist Dirk Hohndel, seemed upbeat about the state of Linux in embedded and Internet of Things applications. Torvalds very presence signaled that embedded Linux, which has often been overshadowed by Linux desktop, server, and cloud technologies, had come of age.
|
||||
|
||||
|
||||
>Linus Torvalds speaking at Embedded Linux Conference.
|
||||
|
||||
IoT was the main topic at ELC, which included an OpenIoT Summit track, and the chief topic in the Torvalds interview.
|
||||
|
||||
“Maybe you won’t see Linux at the IoT leaf nodes, but anytime you have a hub, you will need it,” Torvalds told Hohndel. “You need smart devices especially if you have 23 [IoT standards]. If you have all these stupid devices that don’t necessarily run Linux, and they all talk with slightly different standards, you will need a lot of smart devices. We will never have one completely open standard, one ring to rule them all, but you will have three of four major protocols, and then all these smart hubs that translate.”
|
||||
|
||||
Torvalds remained customarily philosophical when Hohndel asked about the gaping security holes in IoT. “I don’t worry about security because there’s not a lot we can do,” he said. “IoT is unpatchable -- it’s a fact of life.”
|
||||
|
||||
The Linux creator seemed more concerned about the lack of timely upstream contributions from one-off embedded projects, although he noted there have been significant improvements in recent years, partially due to consolidation on hardware.
|
||||
|
||||
“The embedded world has traditionally been hard to interact with as an open source developer, but I think that’s improving,” Torvalds said. “The ARM community has become so much better. Kernel people can now actually keep up with some of the hardware improvements. It’s improving, but we’re not nearly there yet.”
|
||||
|
||||
Torvalds admitted to being more at home on the desktop than in embedded and to having “two left hands” when it comes to hardware.
|
||||
|
||||
“I’ve destroyed things with a soldering iron many times,” he said. “I’m not really set up to do hardware.” On the other hand, Torvalds guessed that if he were a teenager today, he would be fiddling around with a Raspberry Pi or BeagleBone. “The great part is if you’re not great at soldering, you can just buy a new one.”
|
||||
|
||||
Meanwhile, Torvalds vowed to continue fighting for desktop Linux for another 25 years. “I’ll wear them down,” he said with a smile.
|
||||
|
||||
Watch the full video, below.
|
||||
|
||||
Get the Latest on Embedded Linux and IoT. Access 150+ recorded sessions from Embedded Linux Conference 2016. [Watch Now][1].
|
||||
|
||||
[video](https://youtu.be/tQKUWkR-wtM)
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/news/linus-torvalds-talks-iot-smart-devices-security-concerns-and-more-video
|
||||
|
||||
作者：[ERIC BROWN][a]
|
||||
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/users/ericstephenbrown
|
||||
[0]: http://events.linuxfoundation.org/events/embedded-linux-conference
|
||||
[1]: http://go.linuxfoundation.org/elc-openiot-summit-2016-videos?utm_source=lf&utm_medium=blog&utm_campaign=linuxcom
|
||||
|
||||
@ -1,57 +0,0 @@
|
||||
vim-kakali translating
|
||||
|
||||
The Anatomy of a Linux User
|
||||
================================
|
||||
|
||||
|
||||
**Some new GNU/Linux users understand right away that Linux isn’t Windows. Others never quite get it. The best distro designers strive to keep both in mind.**
|
||||
|
||||
### The Heart of Linux
|
||||
|
||||
Nicky isn’t outwardly remarkable in any way. She’s a thirtysomething who decided to go back to school later in life than most. She spent six years in the Navy until she decided a job offer from an old friend would be a better bet than a career in the armed forces. That happens a lot in any of the post-war military service branches. It was at that job where I met her. She was the regional manager for an eight state trucking broker and I was driving for a meat packing outfit in Dallas.
|
||||
|
||||
|
||||
|
||||
We became good friends in 2006, Nicky and me. She’s an outgoing spirit, curious about almost anyone whose path she crosses. We had an ongoing Friday night date to go fight in an indoor laser combat arena. It wasn’t rare for us to burn through three 30 minute sessions in a row. Maybe it wasn’t as cheap as a paint ball arena, but it was climate controlled and had a horror game feel to it. It was during one of those outings that she asked me if I could fix her computer.
|
||||
|
||||
She knew about my efforts to get computers into the homes of disadvantaged kids and I kidded her about paying into Bill Gates’ 401K plan when she complained about her computer becoming too slow. Nicky figured this was as good a time as any to see what Linux was all about.
|
||||
|
||||
Her computer was a decent machine, a mid 2005 Asus desktop with a Dell 19″ monitor. Unfortunately, it had all the obligatory toolbars and popups that a Windows computer can collect when not properly tended. After getting all of the files from the computer, we began the process of installing Linux. We sat together during the install process and I made sure she understood the partitioning process. Inside of an hour, she had a bright new and shiny PCLinuxOS desktop.
|
||||
|
||||
She remarked often, as she navigated her way through her new system, at how beautiful the system looked. She wasn’t mentioning this as an aside; she was almost hypnotized by the sleek beauty in front of her. She remarked that her screen “shimmered” with beauty. That’s something I took away from our install session and have made sure to deploy on every Linux computer I’ve installed since. I want the screen to shimmer for everyone.
|
||||
|
||||
The first week or so, she called or emailed me with the usual questions, but the one that was probably the most important was wanting to know how to save her OpenOffice documents so colleagues could read them. This is key when teaching anyone Linux or Open/LibreOffice. Most people just obey the first popup, allow the document to be saved in Open Document Format and get their fingers bit in the process.
|
||||
|
||||
There was a story going around a year or so ago about a high school kid who claimed he flunked an exam when his professor couldn’t open the file containing his paper. It made for some blustery comments from readers who couldn’t decide who was more of a moron, the kid for not having a clue or his professor for not having a ummm… clue of his own.
|
||||
|
||||
I know some college professors and each and every one of them could figure out how to open an ODF file. Heck, even as much as Microsoft can be grade A, blue-ribbon proprietary jerks, I think Microsoft Office has been able to open an ODT or ODF file for a while now. I can’t say for sure since I haven’t used Microsoft Office much since 2005.
|
||||
|
||||
Even in the bad ol’ days, when Microsoft was openly and flagrantly shoving their way onto enterprise desktops via their vendor lock-in, I never had a problem when conducting business or collaborating with users of Microsoft Office, because I became pro-active and never assumed. I would email the person or people I was to work with and ask what version of Office they were using. From that information, I could make sure to save my documents in a format they could readily open and read.
|
||||
|
||||
But back to Nicky, who put a lot of time into learning about her Linux computer. I was surprised by her enthusiasm.
|
||||
|
||||
Learning how to use Linux on the desktop is made much simpler when the person doing the learning realizes that all habits and tools for using Windows are to be left at the door. Even after telling our Reglue kids this, more often than not when I come back to do a check-up with them there is some_dodgy_file.exe on the desktop or in the download folder.
|
||||
|
||||
While we are in the general vicinity of discussing files, let’s talk about doing updates. For a long time I was dead set against having multiple program installers or updaters on the same computer. In the case of Mint, it was decided to disable the update ability completely within Synaptic and that frosted my flakes. But while for us older folks dpkg and apt are our friends, wise heads have prevailed and have come to understand that the command line doesn’t often seem warm and welcoming to new users.
|
||||
|
||||
I frothed at the mouth and raged against the machine over the crippling of Synaptic until it was ‘splained to me. Do you remember when you were just starting out and had full admin rights to your brand new Linux install? Remember when you combed through the massive amounts of software listed in Synaptic? Remember how you began check marking every cool program you found? Do you remember how many of those cool programs started with the letters “lib”?
|
||||
|
||||
Yeah, me too. I installed and broke a few brand new installations until I found out that those LIB files were the nuts and bolts of the application and not the application itself. That’s why the genius’ behind Linux Mint and Ubuntu have created smart, pretty-to-look-at and easy-to-use application installers. Synaptic is still there for us old heads, but for the people coming up behind us, there are just too many ways to leave a system open to major borks by installing lib files and the like. In the new installers, those files are tucked away and not even shown to the user. And really, that’s the way it should be.
|
||||
|
||||
Unless you are charging for support calls that is.
|
||||
|
||||
There are a lot of smarts built into today’s Linux distros and I applaud those folks because they make my job easier. Not every new user is a Nicky. She was pretty much an install and forget project for me, and she is in the minority. The majority of new Linux users can be needy at times.
|
||||
|
||||
That’s okay. They are the ones who will be teaching their kids how to use Linux.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://fossforce.com/2016/05/anatomy-linux-user/
|
||||
|
||||
作者：[Ken Starks][a]
|
||||
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]: http://linuxlock.blogspot.com/
|
||||
@ -0,0 +1,109 @@
|
||||
chenxinlong translating
|
||||
Who needs a GUI? How to live in a Linux terminal
|
||||
=================================================
|
||||
|
||||
|
||||
|
||||
### The best Linux shell apps for handling common functions
|
||||
|
||||
Ever consider the idea of living entirely in a Linux terminal? No graphical desktop. No modern GUI software. Just text—and nothing but text—inside a Linux shell. It may not be easy, but it’s absolutely doable. [I recently tried living completely in a Linux shell for 30 days][1]. What follows are my favorite shell applications for handling some of the most common bits of computer functionality (web browsing, word processing, etc.). With a few obvious holes. Because being text-only is hard.
|
||||
|
||||
|
||||
|
||||
### Emailing within a Linux terminal
|
||||
|
||||
For emailing in a terminal, we are spoiled for choice. Many people recommend mutt and notmuch. Both of those are powerful and excellent, but I prefer alpine. Why? Not only does it work well, but it’s also much more of a familiar interface if you are used to GUI email software like Thunderbird.
|
||||
|
||||
|
||||
|
||||
### Web browsing within a Linux terminal
|
||||
|
||||
I have one word for you: [w3m][5]. Well, I suppose that’s not even really a word. But w3m is definitely my terminal web browser of choice. It tenders things fairly well and is powerful enough to even let you post to sites such as Google Plus (albeit, not in a terribly fun way). Lynx may be the de facto text-based web browser, but w3m is my favorite.
|
||||
|
||||
|
||||
|
||||
### Text editing within a Linux terminal
|
||||
|
||||
For editing simple text files, I have one application that I straight-up love. No, not emacs. Also, definitely not vim. For editing of a text file or jotting down some notes, I like nano. Yes, nano. It’s simple, easy to learn and pleasant to use. Are there pieces of software with more features? Sure. But nano is just delightful.
|
||||
|
||||
|
||||
|
||||
### Word processing within a Linux terminal
|
||||
|
||||
In a shell—with nothing but text—there really isn’t a huge difference between a “text editor” and a “word processor.” But being as I do a lot of writing, having a piece of software built specifically for long-form writing is a definite must. My favorite is wordgrinder. It has just enough tools to make me happy, a nice menu-driven interface (with hot-keys), and it supports multiple file types, including OpenDocument, HTML and a bunch of other ones.
|
||||
|
||||
|
||||
|
||||
### Music playing within a Linux terminal
|
||||
|
||||
When it comes to playing music (mp3, Ogg, etc.) from a shell, one piece of software is king: [cmus][7]. It supports every conceivable file format. It’s super easy to use and incredibly fast and light on system resource usage. So clean. So streamlined. This is what a good music player should be like.
|
||||
|
||||
|
||||
|
||||
### Instant messaging within a Linux terminal
|
||||
|
||||
When I realized how will I could instant message from the terminal, my head exploded. You know Pidgin, the multi-protocol IM client? Well, it has a version for the terminal, called “[finch][8],” that allows you to connect to multiple networks and chat with multiple people at once. The interface is even similar to Pidgin. Just amazing. Use Google Hangouts? Try [hangups][9]. It has a nice tabbed interface and works amazingly well. Seriously. Other than needing perhaps some emoji and inline pictures, instant messaging from the shell is a great experience.
|
||||
|
||||
|
||||
|
||||
### Tweeting within a Linux terminal
|
||||
|
||||
No joke. Twitter, in your terminal, thanks to [rainbowstream][10]. I hit a few bugs here and there, but overall, it works rather well. Not as well as the website itself—and not as well as the official mobile clients—but, come on, this is Twitter in a shell. Even if it has one or two rough edges, this is pretty stinkin’ cool.
|
||||
|
||||
|
||||
|
||||
### Reddit-ing within a Linux terminal
|
||||
|
||||
Spending time on Reddit from the comforts of the command line feels right somehow. And with rtv, it’s a rather pleasant experience. Reading. Commenting. Voting. It all works. The experience isn’t actually all that different than the website itself.
|
||||
|
||||
|
||||
|
||||
### Process managing within a Linux terminal
|
||||
|
||||
Use [htop][12]. It’s like top—only better and prettier. Sometimes I just leave htop up and running all the time. Just because. In that regard, it’s like a music visualizer—only for RAM and CPU usage.
|
||||
|
||||
|
||||
|
||||
### File managing within a Linux terminal
|
||||
|
||||
Just because you’re in a text-based shell doesn’t mean you don’t enjoy the finer things in life. Like having a nice file browser and manager. In that regard, [Midnight Commander][13] is a pretty doggone great one.
|
||||
|
||||
|
||||
|
||||
### Terminal managing within a Linux terminal
|
||||
|
||||
If you spend much time in the shell, you’re going to need a terminal multiplexer. Basically it’s a piece of software that lets you split up your terminal session into a customizable grid, allowing you to use and see multiple terminal applications at the same time. It’s a tiled window manager for your shell. My favorite is [tmux][14]. But [GNU Screen][15] is also quite nice. It might take a few minutes to learn how to use it, but once you do, you’ll be glad you did.
|
||||
|
||||
|
||||
|
||||
### Presentation-ing within a Linux terminal
|
||||
|
||||
LibreOffice, Google Slides or, gasp, PowerPoint. I spend a lot of time in presentation software. The fact that one exists for the shell pleases me greatly. It’s called, appropriately, “[text presentation program][16].” There are no images (obviously), just a simple program for displaying slides put together in a simple markup language. It may not let you embed pictures of cats, but you’ll earn some serious nerd-cred for doing an entire presentation from the terminal.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.networkworld.com/article/3091139/linux/who-needs-a-gui-how-to-live-in-a-linux-terminal.html#slide1
|
||||
|
||||
作者：[Bryan Lunduke][a]
|
||||
译者：[译者ID](https://github.com/chenxinlong)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: http://www.networkworld.com/author/Bryan-Lunduke/
|
||||
[1]: http://www.networkworld.com/article/3083268/linux/30-days-in-a-terminal-day-0-the-adventure-begins.html
|
||||
[2]: https://en.wikipedia.org/wiki/Mutt_(email_client)
|
||||
[3]: https://notmuchmail.org/
|
||||
[4]: https://en.wikipedia.org/wiki/Alpine_(email_client)
|
||||
[5]: https://en.wikipedia.org/wiki/W3m
|
||||
[6]: http://cowlark.com/wordgrinder/index.html
|
||||
[7]: https://en.wikipedia.org/wiki/Cmus
|
||||
[8]: https://developer.pidgin.im/wiki/Using%20Finch
|
||||
[9]: https://github.com/tdryer/hangups
|
||||
[10]: http://www.rainbowstream.org/
|
||||
[11]: https://github.com/michael-lazar/rtv
|
||||
[12]: http://hisham.hm/htop/
|
||||
[13]: https://en.wikipedia.org/wiki/Midnight_Commander
|
||||
[14]: https://tmux.github.io/
|
||||
[15]: https://en.wikipedia.org/wiki/GNU_Screen
|
||||
[16]: http://www.ngolde.de/tpp.html
|
||||
@ -1,110 +0,0 @@
|
||||
Ubuntu Snap takes charge of Linux desktop and IoT software distribution
|
||||
===========================================================================
|
||||
|
||||
[Canonical][28] and [Ubuntu][29] founder Mark Shuttleworth said in an interview that he hadn't planned on an announcement about Ubuntu's new [Snap app package format][30]. But then in a matter of a few months, developers from multiple Linux distributions and companies announced they would use Snap as a universal Linux package format.
|
||||
|
||||
|
||||
>Linux distributors, ISVs, and companies are all adopting Ubuntu Snap to distribute and update programs across all Linux varieties.
|
||||
|
||||
Why? Because Snap enables a single binary package to work perfectly and securely on any Linux desktop, server, cloud or device. According to Olli Ries, head of Canonical's Ubuntu client platform products and releases:
|
||||
|
||||
>The [security mechanisms in Snap packages][1] allow us to open up the platform for much faster iteration across all our flavors as Snap applications are isolated from the rest of the system. Users can install a Snap without having to worry whether it will have an impact on their other apps or their system.
|
||||
|
||||
Of course, as Matthew Garrett, a former Linux kernel developer and CoreOS security developer, has pointed out: If you [use Snap with an insecure program, such as the X11][2] window system, you don't actually gain any security.
|
||||
|
||||
Shuttleworth agrees with Garrett but points out that you can control how Snap applications interact with the rest of this system. So, for example, a web browser can be contained within a secure Snap, which uses the Ubuntu packaged [openssl][3] Transport Layer Security (TLS) and Secure Sockets Layer (SSL) library. In addition, even if something does break into the browser instance, it still can't get to the underlying operating system.
|
||||
|
||||
Many companies agree. [Dell][4], [Samsung][5], [Mozilla][6], [Krita][7], [Mycroft][8], and [Horizon Computing][9] are adopting Snap. [Arch Linux][10], [Debian][11], [Gentoo][12], and [OpenWrt][13] developers have also embraced Snaps and are adding it to their Linux distributions
|
||||
|
||||
Snap packages, aka "Snaps", now work natively on Arch, Debian, Fedora, Kubuntu, Lubuntu, Ubuntu GNOME, Ubuntu Kylin, Ubuntu MATE, Ubuntu Unity, and Xubuntu. Snap is being validated on CentOS, Elementary, Gentoo, Mint, OpenSUSE, and Red Hat Enterprise Linux (RHEL), and are easy to enable on other Linux distributions.
|
||||
|
||||
These distributions are adopting Snaps, Shuttleworth explained, because "Snaps bring those apps to every Linux desktop, server, device or cloud machine, giving users freedom to choose any Linux distribution while retaining access to the best apps."
|
||||
|
||||
Taken together these distributions represent the vast majority of common Linux desktop, server and cloud distributions. Why would they switch from their existing package management systems? "One nice feature of Snaps is support for edge and beta channels, which allow users to opt-in to the pre-release developer versions of software or stick with the latest stable versions." explained Tim Jester-Pfadt, an Arch Linux contributor.
|
||||
|
||||
In addition to the Linux distributors, independent software vendors (ISVs) are embracing Snap since it greatly simplifies third-party Linux app distribution and security maintenance. For example, [The Document Foundation][14] will be making the popular open-source office suite [LibreOffice][15] available as a Snap.
|
||||
|
||||
Thorsten Behrens, co-founder of The Document Foundation explained:
|
||||
|
||||
>Our objective is to make LibreOffice easily available to as many users as possible. Snaps enable our users to get the freshest LibreOffice releases across different desktops and distributions quickly, easily and consistently. As a bonus, it should help our release engineers to eventually move away from bespoke, home-grown and ancient Linux build solutions, towards something that is collectively maintained.
|
||||
|
||||
In a statement, Nick Nguyen, Mozilla's [Firefox][16] VP, added:
|
||||
|
||||
>We strive to offer users a great experience and make Firefox available across many platforms, devices and operating systems. With the introduction of Snaps, continually optimizing Firefox will become possible, providing Linux users the most up-to-date features.
|
||||
|
||||
Boudewijn Rempt, project lead at the [Krita Foundation][17], a KDE-based graphics program, said:
|
||||
|
||||
>Maintaining DEB packages in a private repository was complex and time consuming, snaps are much easier to maintain, package and distribute. Putting the snap in the store was particularly simple, this is the most streamlined app store I have published software in. [Krita 3.0][18] has just been released as a snap which will be updated automatically as newer versions become available.
|
||||
|
||||
It's not just Linux desktop programmers who are excited by Snap. Internet of Things (IoT) and embedded developers are also grabbing on to Snap with both hands.
|
||||
|
||||
Because Snaps are isolated from one another to help with data security, and can be updated or rolled back automatically, they are ideal for devices. Multiple vendors have launched snappy IoT devices, enabling a new class of "smart edge" device with IoT app store. Snappy devices receive automatic updates for the base OS, together with updates to the apps installed on the device.
|
||||
|
||||
Dell, which according to Shuttleworth was one of the first IoT vendors to see the power of Snap, will be using Snap in its devices.
|
||||
|
||||
"We believe Snaps address the security risks and manageability challenges associated with deploying and running multiple third party applications on a single IoT Gateway," said Jason Shepherd, Dell's Director of IoT Strategy and Partnerships. "This trusted and universal app format is essential for Dell, our IoT Solutions Partners and commercial customers to build a scalable, IT-ready, and vibrant ecosystem of IoT applications."
|
||||
|
||||
It's simple, explained OpenWrt developer Matteo Croce. "Snaps deliver new applications to OpenWrt while leaving the core OS unchanged.... Snaps are a faster way to deliver a wider range of software to supported OpenWrt access points and routers."
|
||||
|
||||
Shuttleworth doesn't see Snaps replacing existing Linux package systems such as [RPM][19] and [DEB][20]. Instead he sees it as being complementary to them. Snaps will sit alongside the native package. Each distribution has its own mechanisms to provide and update the core operating system and its updates. What Snap brings to the table is universal apps that cannot interfere with the base operating system
|
||||
|
||||
Each Snap is confined using a range of kernel isolation and security mechanisms, tailored to the Snap application's needs. A careful review process ensures that snaps only receive the permissions they require to operate. Users will not have to make complex security decisions when installing the snap.
|
||||
|
||||
Since Snaps are essentially self-contained zip files that can be quickly executed in place, "Snaps are much easier to create than traditional Linux packages, and allow us to evolve dependencies independent of the base operating system, so we can easily provide the very best and latest Chinese Linux apps to users across all distributions," explained Jack Yu, leader of the popular [Chinese Ubuntu Kylin][21] team.
|
||||
|
||||
The snap format, designed by Canonical, is handled by [snapd][22]. Its development work is done on [GitHub][23]. Porting snapd to a wide range of Linux distributions has proven straightforward, and the community has grown to include contributors from a wide range of Linux backgrounds.
|
||||
|
||||
Snap packages are created with the snapcrafttool. The home of the project is [snapcraft.io][24], which includes a tour and step-by-step guides to Snap creation, along with documentation for users and contributors to the project. Snaps can be built from existing distribution packages, but are more commonly built from source for optimization and size efficiency.
|
||||
|
||||
Unless you're an Ubuntu power-user or serious Linux developer you may not have heard of Snap. In the future, anyone who does work with Linux on any platform will know the program. It's well on its way to becoming a major -- perhaps the most important of all -- Linux application installation and upgrade mechanism.
|
||||
|
||||
#### Related Stories:
|
||||
|
||||
- [Linux expert Matthew Garrett: Ubuntu 16.04's new Snap format is a security risk][25]
|
||||
- [Ubuntu Linux 16.04 is here][26]
|
||||
- [Microsoft and Canonical partner to bring Ubuntu to Windows 10][27]
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.zdnet.com/article/ubuntu-snap-takes-charge-of-linux-desktop-and-iot-software-distribution/
|
||||
|
||||
作者：[Steven J. Vaughan-Nichols][a]
|
||||
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]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/
|
||||
[28]: http://www.canonical.com/
|
||||
[29]: http://www.ubuntu.com/
|
||||
[30]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/
|
||||
[1]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/
|
||||
[2]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/
|
||||
[3]: https://www.openssl.org/
|
||||
[4]: http://www.dell.com/en-us/
|
||||
[5]: http://www.samsung.com/us/
|
||||
[6]: http://www.mozilla.com/
|
||||
[7]: https://krita.org/en/
|
||||
[8]: https://mycroft.ai/
|
||||
[9]: http://www.horizon-computing.com/
|
||||
[10]: https://www.archlinux.org/
|
||||
[11]: https://www.debian.org/
|
||||
[12]: https://www.gentoo.org/
|
||||
[13]: https://openwrt.org/
|
||||
[14]: https://www.documentfoundation.org/
|
||||
[15]: https://www.libreoffice.org/download/libreoffice-fresh/
|
||||
[16]: https://www.mozilla.org/en-US/firefox/new/
|
||||
[17]: https://krita.org/en/about/krita-foundation/
|
||||
[18]: https://krita.org/en/item/krita-3-0-released/
|
||||
[19]: http://rpm5.org/
|
||||
[20]: https://www.debian.org/doc/manuals/debian-faq/ch-pkg_basics.en.html
|
||||
[21]: http://www.ubuntu.com/desktop/ubuntu-kylin
|
||||
[22]: https://launchpad.net/ubuntu/+source/snapd
|
||||
[23]: https://github.com/snapcore/snapd
|
||||
[24]: http://snapcraft.io/
|
||||
[25]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/
|
||||
[26]: http://www.zdnet.com/article/ubuntu-linux-16-04-is-here/
|
||||
[27]: http://www.zdnet.com/article/microsoft-and-canonical-partner-to-bring-ubuntu-to-windows-10/
|
||||
|
||||
|
||||
125
sources/talk/20160620 5 SSH Hardening Tips.md
Normal file
125
sources/talk/20160620 5 SSH Hardening Tips.md
Normal file
@ -0,0 +1,125 @@
|
||||
5 SSH Hardening Tips
|
||||
======================
|
||||
|
||||
|
||||
>Make your OpenSSH sessions more secure with these simple tips.
|
||||
> Creative Commons Zero
|
||||
|
||||
When you look at your SSH server logs, chances are they are full of attempted logins from entities of ill intent. Here are 5 general ways (along with several specific tactics) to make your OpenSSH sessions more secure.
|
||||
|
||||
### 1. Make Password Auth Stronger
|
||||
|
||||
Password logins are convenient, because you can log in from any machine anywhere. But they are vulnerable to brute-force attacks. Try these tactics for strengthening your password logins.
|
||||
|
||||
- Use a password generator, such as pwgen. pwgen takes several options; the most useful is password length (e.g., pwgen 12 generates a 12-character password).
|
||||
|
||||
- Never reuse a password. Ignore all the bad advice about not writing down your passwords, and keep a notebook with your logins written in it. If you don't believe me that this is a good idea, then believe security guru [Bruce Schneier][1]. If you're reasonably careful, nobody will ever find your notebook, and it is immune from online attacks.
|
||||
|
||||
- You can add extra protection to your login notebook by obscuring the logins recorded in your notebook with character substitution or padding. Use a simple, easily-memorable convention such as padding your passwords with two extra random characters, or use a single simple character substitution such as # for *.
|
||||
|
||||
- Use a non-standard listening port on your SSH server. Yes, this is old advice, and it's still good. Examine your logs; chances are that port 22 is the standard attack point, with few attacks on other ports.
|
||||
|
||||
- Use [Fail2ban][2] to dynamically protect your server from brute force attacks.
|
||||
|
||||
- Create non-standard usernames. Never ever enable a remote root login, and avoid "admin".
|
||||
|
||||
### 2. Fix Too Many Authentication Failures
|
||||
|
||||
When my ssh logins fail with "Too many authentication failures for carla" error messages, it makes me feel bad. I know I shouldn't take it personally, but it still stings. But, as my wise granny used to say, hurt feelings don't fix the problem. The cure for this is to force a password-based login in your ~/.ssh/config file. If this file does not exist, first create the ~/.ssh/ directory:
|
||||
|
||||
```
|
||||
$ mkdir ~/.ssh
|
||||
$ chmod 700 ~/.ssh
|
||||
```
|
||||
|
||||
Then create the `~/.ssh/config` file in a text editor and enter these lines, using your own remote HostName address:
|
||||
|
||||
```
|
||||
HostName remote.site.com
|
||||
PubkeyAuthentication=no
|
||||
```
|
||||
|
||||
### 3. Use Public Key Authentication
|
||||
|
||||
Public Key authentication is much stronger than password authentication, because it is immune to brute-force password attacks, but it’s less convenient because it relies on RSA key pairs. To begin, you create a public/private key pair. Next, the private key goes on your client computer, and you copy the public key to the remote server that you want to log into. You can log in to the remote server only from computers that have your private key. Your private key is just as sensitive as your house key; anyone who has possession of it can access your accounts. You can add a strong layer of protection by putting a passphrase on your private key.
|
||||
|
||||
Using RSA key pairs is a great tool for managing multiple users. When a user leaves, disable their login by deleting their public key from the server.
|
||||
|
||||
This example creates a new key pair of 3072 bits strength, which is stronger than the default 2048 bits, and gives it a unique name so you know what server it belongs to:
|
||||
|
||||
```
|
||||
$ ssh-keygen -t rsa -b 3072 -f id_mailserver
|
||||
```
|
||||
|
||||
This creates two new keys, id_mailserver and id_mailserver.pub. id_mailserver is your private key -- do not share this! Now securely copy your public key to your remote server with the ssh-copy-id command. You must already have a working SSH login on the remote server:
|
||||
|
||||
```
|
||||
$ ssh-copy-id -i id_rsa.pub user@remoteserver
|
||||
|
||||
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
|
||||
user@remoteserver's password:
|
||||
|
||||
Number of key(s) added: 1
|
||||
|
||||
Now try logging into the machine, with: "ssh 'user@remoteserver'"
|
||||
and check to make sure that only the key(s) you wanted were added.
|
||||
```
|
||||
|
||||
ssh-copy-id ensures that you will not accidentally copy your private key. Test your new key login by copying the example from your command output, with single quotes:
|
||||
|
||||
```
|
||||
$ ssh 'user@remoteserver'
|
||||
```
|
||||
|
||||
It should log you in using your new key, and if you set a password on your private key, it will prompt you for it.
|
||||
|
||||
### 4. Disable Password Logins
|
||||
|
||||
Once you have tested and verified your public key login, disable password logins so that your remote server is not vulnerable to brute force password attacks. Do this in the /etc/sshd_config file on your remote server with this line:
|
||||
|
||||
```
|
||||
PasswordAuthentication no
|
||||
```
|
||||
|
||||
Then restart your SSH daemon.
|
||||
|
||||
### 5. Set Up Aliases -- They’re Fast and Cool
|
||||
|
||||
You can set up aliases for remote logins that you use a lot, so instead of logging in with something like "ssh -u username -p 2222 remote.site.with.long-name", you can use "ssh remote1". Set it up like this in your ~/.ssh/config file:
|
||||
|
||||
```
|
||||
Host remote1
|
||||
HostName remote.site.with.long-name
|
||||
Port 2222
|
||||
User username
|
||||
PubkeyAuthentication no
|
||||
```
|
||||
|
||||
If you are using public key authentication, it looks like this:
|
||||
|
||||
```
|
||||
Host remote1
|
||||
HostName remote.site.with.long-name
|
||||
Port 2222
|
||||
User username
|
||||
IdentityFile ~/.ssh/id_remoteserver
|
||||
```
|
||||
|
||||
The [OpenSSH documentation][3] is long and detailed, but after you have mastered basic SSH use, you'll find it's very useful and contains a trove of cool things you can do with OpenSSH.
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/learn/5-ssh-hardening-tips
|
||||
|
||||
作者：[CARLA SCHRODER][a]
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.linux.com/users/cschroder
|
||||
[1]: https://www.schneier.com/blog/archives/2005/06/write_down_your.html
|
||||
[2]: http://www.fail2ban.org/wiki/index.php/Main_Page
|
||||
[3]: http://www.openssh.com/
|
||||
@ -1,63 +0,0 @@
|
||||
[Cathon is translating]
|
||||
Training vs. hiring to meet the IT needs of today and tomorrow
|
||||
================================================================
|
||||
|
||||
|
||||
|
||||
In the digital era, IT skills requirements are in a constant state of flux thanks to the constant change of the tools and technologies companies need to keep pace. It’s not easy for companies to find and hire talent with coveted skills that will enable them to innovate. Meanwhile, training internal staff to take on new skills and challenges takes time that is often in short supply.
|
||||
|
||||
[Sandy Hill][1] is quite familiar with the various skills required across a variety of IT disciplines. As the director of IT for [Pegasystems][2], she is responsible for IT teams involved in areas ranging from application development to data center operations. What’s more, Pegasystems develops applications to help sales, marketing, service and operations teams streamline operations and connect with customers, which means she has to grasp the best way to use IT resources internally, and the IT challenges the company’s customers face.
|
||||
|
||||
|
||||
|
||||
**The Enterprisers Project (TEP): How has the emphasis you put on training changed in recent years?**
|
||||
|
||||
**Hill**: We’ve been growing exponentially over the past couple of years so now we’re implementing more global processes and procedures. With that comes the training aspect of making sure everybody is on the same page.
|
||||
|
||||
Most of our focus has shifted to training staff on new products and tools that get implemented to drive innovation and enhance end user productivity. For example, we’ve implemented an asset management system; we didn’t have one before. So we had to do training globally instead of hiring someone who already knew the product. As we’re growing, we’re also trying to maintain a tight budget and flat headcount. So we’d rather internally train than try to hire new people.
|
||||
|
||||
**TEP: Describe your approach to training. What are some of the ways you help employees evolve their skills?**
|
||||
|
||||
**Hill**: I require each staff member to have a technical and non-technical training goal, which are tracked and reported on as part of their performance review. Their technical goal needs to align within their job function, and the non-technical goal can be anything from focusing on sharpening one of their soft skills to learning something outside of their area of expertise. I perform yearly staff evaluations to see where the gaps and shortages are so that teams remain well-rounded.
|
||||
|
||||
**TEP: To what extent have your training initiatives helped quell recruitment and retention issues?**
|
||||
|
||||
**Hill**: Keeping our staff excited about learning new technologies keeps their skill sets sharp. Having the staff know that we value them, and we are vested in their professional growth and development motivates them.
|
||||
|
||||
**TEP: What sorts of training have you found to be most effective?**
|
||||
|
||||
**Hill**: We use several different training methods that we’ve found to be effective. With new or special projects, we try to incorporate a training curriculum led by the vendor as part of the project rollout. If that’s not an option, we use off-site training. We also purchase on-line training packages, and I encourage my staff to attend at least one conference per year to keep up with what’s new in the industry.
|
||||
|
||||
**TEP**: For what sorts of skills have you found it’s better to hire new people than train existing staff?
|
||||
|
||||
**Hill**: It depends on the project. In one recent initiative, trying to implement OpenStack, we didn’t have internal expertise at all. So we aligned with a consulting firm that specialized in that area. We utilized their expertise on-site to help run the project and train internal team members. It was a massive undertaking to get internal people to learn the skills they needed while also doing their day-to-day jobs.
|
||||
|
||||
The consultant helped us determine the headcount we needed to be proficient. This allowed us to assess our staff to see if gaps remained, which would require additional training or hiring. And we did end up hiring some of the contractors. But the alternative was to send some number of FTEs (full-time employees) for 6 to 8 weeks of training, and our pipeline of projects wouldn’t allow that.
|
||||
|
||||
**TEP: In thinking about some of your most recent hires, what skills did they have that are especially attractive to you?**
|
||||
|
||||
**Hill**: In recent hires, I’ve focused on soft skills. In addition to having solid technical skills, they need to be able to communicate effectively, work in teams and have the ability to persuade, negotiate and resolve conflicts.
|
||||
|
||||
IT people in general kind of keep to themselves; they’re often not the most social people. Now, where IT is more integrated throughout the organization, the ability to give useful updates and status reports to other business units is critical to show that IT is an active presence and to be successful.
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://linoxide.com/firewall/pfsense-setup-basic-configuration/
|
||||
|
||||
作者：[ Paul Desmond][a]
|
||||
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://enterprisersproject.com/user/paul-desmond
|
||||
[1]: https://enterprisersproject.com/user/sandy-hill
|
||||
[2]: https://www.pega.com/pega-can?&utm_source=google&utm_medium=cpc&utm_campaign=900.US.Evaluate&utm_term=pegasystems&gloc=9009726&utm_content=smAXuLA4U|pcrid|102822102849|pkw|pegasystems|pmt|e|pdv|c|
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,101 @@
|
||||
Tips for managing your project's issue tracker
|
||||
==============================================
|
||||
|
||||
|
||||
|
||||
Issue-tracking systems are important for many open source projects, and there are many open source tools that provide this functionality but many projects opt to use GitHub's built-in issue tracker.
|
||||
|
||||
Its simple structure makes it easy for others to weigh in, but issues are really only as good as you make them.
|
||||
|
||||
Without a process, your repository can become unwieldy, overflowing with duplicate issues, vague feature requests, or confusing bug reports. Project maintainers can become burdened by the organizational load, and it can become difficult for new contributors to understand where priorities lie.
|
||||
|
||||
In this article, I'll discuss how to take your GitHub issues from good to great.
|
||||
|
||||
### The issue as user story
|
||||
|
||||
My team spoke with open source expert [Jono Bacon][1]—author of [The Art of Community][2], a strategy consultant, and former Director of Community at GitHub—who said that high-quality issues are at the core of helping a projects succeed. He says that while some see issues as merely a big list of problems you have to tend to, well-managed, triaged, and labeled issues can provide incredible insight into your code, your community, and where the problem spots are.
|
||||
|
||||
"At the point of submission of an issue, the user likely has little patience or interest in providing expansive detail. As such, you should make it as easy as possible to get the most useful information from them in the shortest time possible," Jono Bacon said.
|
||||
|
||||
A consistent structure can take a lot of burden off project maintainers, particularly for open source projects. We've found that encouraging a user story approach helps make clarity a constant. The common structure for a user story addresses the "who, what, and why" of a feature: As a [user type], I want to [task] so that [goal].
|
||||
|
||||
Here's what that looks like in practice:
|
||||
|
||||
>As a customer, I want to create an account so that I can make purchases.
|
||||
|
||||
We suggest sticking that user story in the issue's title. You can also set up [issue templates][3] to keep things consistent.
|
||||
|
||||
|
||||
> Issue templates bring consistency to feature requests.
|
||||
|
||||
The point is to make the issue well-defined for everyone involved: it identifies the audience (or user), the action (or task), and the outcome (or goal) as simply as possible. There's no need to obsess over this structure, though; as long as the what and why of a story are easy to spot, you're good.
|
||||
|
||||
### Qualities of a good issue
|
||||
|
||||
Not all issues are created equal—as any OSS contributor or maintainer can attest. A well-formed issue meets these qualities outlined in [The Agile Samurai][4].
|
||||
|
||||
Ask yourself if it is...
|
||||
|
||||
- something of value to customers
|
||||
- avoids jargon or mumbo jumbo; a non-expert should be able to understand it
|
||||
- "slices the cake," which means it goes end-to-end to deliver something of value
|
||||
- independent from other issues if possible; dependent issues reduce flexibility of scope
|
||||
- negotiable, meaning there are usually several ways to get to the stated goal
|
||||
- small and easily estimable in terms of time and resources required
|
||||
- measurable; you can test for results
|
||||
|
||||
### What about everything else? Working with constraints
|
||||
|
||||
If an issue is difficult to measure or doesn't seem feasible to complete within a short time period, you can still work with it. Some people call these "constraints."
|
||||
|
||||
For example, "the product needs to be fast" doesn't fit the story template, but it is non-negotiable. But how fast is fast? Vague requirements don't meet the criteria of a "good issue", but if you further define these concepts—for example, "the product needs to be fast" can be "each page needs to load within 0.5 seconds"—you can work with it more easily. Constraints can be seen as internal metrics of success, or a landmark to shoot for. Your team should test for them periodically.
|
||||
|
||||
### What's inside your issue?
|
||||
|
||||
In agile, user stories typically include acceptance criteria or requirements. In GitHub, I suggest using markdown checklists to outline any tasks that make up an issue. Issues should get more detail as they move up in priority.
|
||||
|
||||
Say you're creating an issue around a new homepage for a website. The sub-tasks for that task might look something like this.
|
||||
|
||||
|
||||
>Use markdown checklists to split a complicated issue into several parts.
|
||||
|
||||
If necessary, link to other issues to further define a task. (GitHub makes this really easy.)
|
||||
|
||||
Defining features as granularly as possible makes it easier to track progress, test for success, and ultimately ship valuable code more frequently.
|
||||
|
||||
Once you've gathered some data points in the form of issues, you can use APIs to glean deeper insight into the health of your project.
|
||||
|
||||
"The GitHub API can be hugely helpful here in identifying patterns and trends in your issues," Bacon said. "With some creative data science, you can identify problem spots in your code, active members of your community, and other useful insights."
|
||||
|
||||
Some issue management tools provide APIs that add additional context, like time estimates or historical progress.
|
||||
|
||||
### Getting others on board
|
||||
|
||||
Once your team decides on an issue structure, how do you get others to buy in? Think of your repo's ReadMe.md file as your project's "how-to." It should clearly define what your project does (ideally using searchable language) and explain how others can contribute (by submitting requests, bug reports, suggestions, or by contributing code itself.)
|
||||
|
||||
|
||||
>Edit your ReadMe file with clear instructions for new collaborators.
|
||||
|
||||
This is the perfect spot to share your GitHub issue guidelines. If you want feature requests to follow the user story format, share that here. If you use a tracking tool to organize your product backlog, share the badge so others can gain visibility.
|
||||
|
||||
"Issue templates, sensible labels, documentation for how to file issues, and ensuring your issues get triaged and responded to quickly are all important" for your open source project, Bacon said.
|
||||
|
||||
Remember: It's not about adding process for the process' sake. It's about setting up a structure that makes it easy for others to discover, understand, and feel confident contributing to your community.
|
||||
|
||||
"Focus your community growth efforts not just on growing the number of programmers, but also [on] people interested in helping issues be accurate, up to date, and a source of active conversation and productive problem solving," Bacon said.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/7/how-take-your-projects-github-issues-good-great
|
||||
|
||||
作者：[Matt Butler][a]
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/mattzenhub
|
||||
[1]: http://www.jonobacon.org/
|
||||
[2]: http://www.artofcommunityonline.org/
|
||||
[3]: https://help.github.com/articles/creating-an-issue-template-for-your-repository/
|
||||
[4]: https://www.amazon.ca/Agile-Samurai-Masters-Deliver-Software/dp/1934356581
|
||||
@ -1,110 +0,0 @@
|
||||
Translating by ivo-wang
|
||||
What is good stock portfolio management software on Linux
|
||||
================================================================================
|
||||
If you are investing in the stock market, you probably understand the importance of a sound portfolio management plan. The goal of portfolio management is to come up with the best investment plan tailored for you, considering your risk tolerance, time horizon and financial goals. Given its importance, no wonder there are no shortage of commercial portfolio management apps and stock market monitoring software, each touting various sophisticated portfolio performance tracking and reporting capabilities.
|
||||
|
||||
For those of you Linux aficionados who are looking for a **good open-source portfolio management tool** to manage and track your stock portfolio on Linux, I would highly recommend a Java-based portfolio manager called [JStock][1]. If you are not a big Java fan, you might be turned off by the fact that JStock runs on a heavyweight JVM. At the same time I am sure many people will appreciate the fact that JStock is instantly accessible on every Linux platform with JRE installed. No hoops to jump through to make it work on your Linux environment.
|
||||
|
||||
The day is gone when "open-source" means "cheap" or "subpar". Considering that JStock is just a one-man job, JStock is impressively packed with many useful features as a portfolio management tool, and all that credit goes to Yan Cheng Cheok! For example, JStock supports price monitoring via watchlists, multiple portfolios, custom/built-in stock indicators and scanners, support for 27 different stock markets and cross-platform cloud backup/restore. JStock is available on multiple platforms (Linux, OS X, Android and Windows), and you can save and restore your JStock portfolios seamlessly across different platforms via cloud backup/restore.
|
||||
|
||||
Sounds pretty neat, huh? Now I am going to show you how to install and use JStock in more detail.
|
||||
|
||||
### Install JStock on Linux ###
|
||||
|
||||
Since JStock is written in Java, you must [install JRE][2] to run it. Note that JStock requires JRE 1.7 or higher. If your JRE version does not meet this requirement, JStock will fail with the following error.
|
||||
|
||||
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/yccheok/jstock/gui/JStock : Unsupported major.minor version 51.0
|
||||
|
||||
Once you install JRE on your Linux, download the latest JStock release from the official website, and launch it as follows.
|
||||
|
||||
$ wget https://github.com/yccheok/jstock/releases/download/release_1-0-7-13/jstock-1.0.7.13-bin.zip
|
||||
$ unzip jstock-1.0.7.13-bin.zip
|
||||
$ cd jstock
|
||||
$ chmod +x jstock.sh
|
||||
$ ./jstock.sh
|
||||
|
||||
In the rest of the tutorial, let me demonstrate several useful features of JStock.
|
||||
|
||||
### Monitor Stock Price Movements via Watchlist ###
|
||||
|
||||
On JStock you can monitor stock price movement and automatically get notified by creating one or more watchlists. In each watchlist, you can add multiple stocks you are interested in. Then add your alert thresholds under "Fall Below" and "Rise Above" columns, which correspond to minimum and maximum stock prices you want to set, respectively.
|
||||
|
||||
|
||||
|
||||
For example, if you set minimum/maximum prices of AAPL stock to $102 and $115.50, you will be alerted via desktop notifications if the stock price goes below $102 or moves higher than $115.50 at any time.
|
||||
|
||||
You can also enable email alert option, so that you will instead receive email notifications for such price events. To enable email alerts, go to "Options" menu. Under "Alert" tab, turn on "Send message to email(s)" box, and enter your Gmail account. Once you go through Gmail authorization steps, JStock will start sending email alerts to that Gmail account (and optionally CC to any third-party email address).
|
||||
|
||||
|
||||
|
||||
### Manage Multiple Portfolios ###
|
||||
|
||||
JStock allows you to manage multiple portfolios. This feature is useful if you are using multiple stock brokers. You can create a separate portfolio for each broker and manage your buy/sell/dividend transactions on a per-broker basis. You can switch different portfolios by choosing a particular portfolio under "Portfolio" menu. The following screenshot shows a hypothetical portfolio.
|
||||
|
||||
|
||||
|
||||
Optionally you can enable broker fee option, so that you can enter any broker fees, stamp duty and clearing fees for each buy/sell transaction. If you are lazy, you can enable fee auto-calculation and enter fee schedules for each brokering firm from the option menu beforehand. Then JStock will automatically calculate and enter fees when you add transactions to your portfolio.
|
||||
|
||||
|
||||
|
||||
### Screen Stocks with Built-in/Custom Indicators ###
|
||||
|
||||
If you are doing any technical analysis on stocks, you may want to screen stocks based on various criteria (so-called "stock indicators"). For stock screening, JStock offers several [pre-built technical indicators][3] that capture upward/downward/reversal trends of individual stocks. The following is a list of available indicators.
|
||||
|
||||
- Moving Average Convergence Divergence (MACD)
|
||||
- Relative Strength Index (RSI)
|
||||
- Money Flow Index (MFI)
|
||||
- Commodity Channel Index (CCI)
|
||||
- Doji
|
||||
- Golden Cross, Death Cross
|
||||
- Top Gainers/Losers
|
||||
|
||||
To install any pre-built indicator, go to "Stock Indicator Editor" tab on JStock. Then click on "Install" button in the right-side panel. Choose "Install from JStock server" option, and then install any indicator(s) you want.
|
||||
|
||||
|
||||
|
||||
Once one or more indicators are installed, you can scan stocks using them. Go to "Stock Indicator Scanner" tab, click on "Scan" button at the bottom, and choose any indicator.
|
||||
|
||||
|
||||
|
||||
Once you select the stocks to scan (e.g., NYSE, NASDAQ), JStock will perform scan, and show a list of stocks captured by the indicator.
|
||||
|
||||
|
||||
|
||||
Besides pre-built indicators, you can also define custom indicator(s) on your own with a GUI-based indicator editor. The following example screens for stocks whose current price is less than or equal to its 60-day average price.
|
||||
|
||||
|
||||
|
||||
### Cloud Backup and Restore between Linux and Android JStock ###
|
||||
|
||||
Another nice feature of JStock is cloud backup and restore. JStock allows you to save and restore your portfolios/watchlists via Google Drive, and this features works seamlessly across different platforms (e.g., Linux and Android). For example, if you saved your JStock portfolios to Google Drive on Android, you can restore them on Linux version of JStock.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
If you don't see your portfolios/watchlists after restoring from Google Drive, make sure that your country is correctly set under "Country" menu.
|
||||
|
||||
JStock Android free version is available from [Google Play store][4]. You will need to upgrade to premium version for one-time payment if you want to use its full features (e.g., cloud backup, alerts, charts). I think the premium version is definitely worth it.
|
||||
|
||||
|
||||
|
||||
As a final note, I should mention that its creator, Yan Cheng Cheok, is pretty active in JStock development, and quite responsive in addressing any bugs. Kudos to him!
|
||||
|
||||
What do you think of JStock as portfolio tracking software?
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://xmodulo.com/stock-portfolio-management-software-linux.html
|
||||
|
||||
作者：[Dan Nanni][a]
|
||||
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]:http://xmodulo.com/author/nanni
|
||||
[1]:http://jstock.org/
|
||||
[2]:http://ask.xmodulo.com/install-java-runtime-linux.html
|
||||
[3]:http://jstock.org/ma_indicator.html
|
||||
[4]:https://play.google.com/store/apps/details?id=org.yccheok.jstock.gui
|
||||
@ -1,73 +0,0 @@
|
||||
xinglianfly translate
|
||||
Writing online multiplayer game with python and asyncio - part 1
|
||||
===================================================================
|
||||
|
||||
Have you ever combined async with Python? Here I’ll tell you how to do it and show it on a [working example][1] - a popular Snake game, designed for multiple players.
|
||||
|
||||
[Play gmae][2]
|
||||
|
||||
### 1. Introduction
|
||||
|
||||
Massive multiplayer online games are undoubtedly one of the main trends of our century, in both tech and cultural domains. And while for a long time writing a server for a MMO game was associated with massive budgets and complex low-level programming techniques, things are rapidly changing in the recent years. Modern frameworks based on dynamic languages allow handling thousands of parallel user connections on moderate hardware. At the same time, HTML 5 and WebSockets standards enabled the creation of real-time graphics-based game clients that run directly in web browser, without any extensions.
|
||||
|
||||
Python may be not the most popular tool for creating scalable non-blocking servers, especially comparing to node.js popularity in this area. But the latest versions of Python are aimed to change this. The introduction of [asyncio][3] library and a special [async/await][4] syntax makes asynchronous code look as straightforward as regular blocking code, which now makes Python a worthy choice for asynchronous programming. So I will try to utilize these new features to demonstrate a way to create an online multiplayer game.
|
||||
|
||||
### 2. Getting asynchronous
|
||||
|
||||
A game server should handle a maximum possible number of parallel users' connections and process them all in real time. And a typical solution - creating threads, doesn't solve a problem in this case. Running thousands of threads requires CPU to switch between them all the time (it is called context switching), which creates big overhead, making it very ineffective. Even worse with processes, because, in addition, they do occupy too much memory. In Python there is even one more problem - regular Python interpreter (CPython) is not designed to be multithreaded, it aims to achieve maximum performance for single-threaded apps instead. That's why it uses GIL (global interpreter lock), a mechanism which doesn't allow multiple threads to run Python code at the same time, to prevent uncontrolled usage of the same shared objects. Normally the interpreter switches to another thread when currently running thread is waiting for something, usually a response from I/O (like a response from web server for example). This allows having non-blocking I/O operations in your app, because every operation blocks only one thread instead of blocking the whole server. However, it also makes general multithreading idea nearly useless, because it doesn't allow you to execute python code in parallel, even on multi-core CPU. While at the same time it is completely possible to have non-blocking I/O in one single thread, thus eliminating the need of heavy context-switching.
|
||||
|
||||
Actually, a single-threaded non-blocking I/O is a thing you can do in pure python. All you need is a standard [select][5] module which allows you to write an event loop waiting for I/O from non-blocking sockets. However, this approach requires you to define all the app logic in one place, and soon your app becomes a very complex state-machine. There are frameworks that simplify this task, most popular are [tornado][6] and [twisted][7]. They are utilized to implement complex protocols using callback methods (and this is similar to node.js). The framework runs its own event loop invoking your callbacks on the defined events. And while this may be a way to go for some, it still requires programming in callback style, what makes your code fragmented. Compare this to just writing synchronous code and running multiple copies concurrently, like we would do with normal threads. Why wouldn't this be possible in one thread?
|
||||
|
||||
And this is where the concept of microthreads come in. The idea is to have concurrently running tasks in one thread. When you call a blocking function in one task, behind the scenes it calls a "manager" (or "scheduler") that runs an event loop. And when there is some event ready to process, a manager passes execution to a task waiting for it. That task will also run until it reaches a blocking call, and then it will return execution to a manager again.
|
||||
|
||||
>Microthreads are also called lightweight threads or green threads (a term which came from Java world). Tasks which are running concurrently in pseudo-threads are called tasklets, greenlets or coroutines.
|
||||
|
||||
One of the first implementations of microthreads in Python was [Stackless Python][8]. It got famous because it is used in a very successful online game [EVE online][9]. This MMO game boasts about a persistent universe, where thousands of players are involved in different activities, all happening in the real time. Stackless is a standalone Python interpreter which replaces standard function calling stack and controls the flow directly to allow minimum possible context-switching expenses. Though very effective, this solution remained less popular than "soft" libraries that work with a standard interpreter. Packages like [eventlet][10] and [gevent][11] come with patching of a standard I/O library in the way that I/O function pass execution to their internal event loop. This allows turning normal blocking code into non-blocking in a very simple way. The downside of this approach is that it is not obvious from the code, which calls are non-blocking. A newer version of Python introduced native coroutines as an advanced form of generators. Later in Python 3.4 they included asyncio library which relies on native coroutines to provide single-thread concurrency. But only in python 3.5 coroutines became an integral part of python language, described with the new keywords async and await. Here is a simple example, which illustrates using asyncio to run concurrent tasks:
|
||||
|
||||
```
|
||||
import asyncio
|
||||
|
||||
async def my_task(seconds):
|
||||
print("start sleeping for {} seconds".format(seconds))
|
||||
await asyncio.sleep(seconds)
|
||||
print("end sleeping for {} seconds".format(seconds))
|
||||
|
||||
all_tasks = asyncio.gather(my_task(1), my_task(2))
|
||||
loop = asyncio.get_event_loop()
|
||||
loop.run_until_complete(all_tasks)
|
||||
loop.close()
|
||||
```
|
||||
|
||||
We launch two tasks, one sleeps for 1 second, the other - for 2 seconds. The output is:
|
||||
|
||||
```
|
||||
start sleeping for 1 seconds
|
||||
start sleeping for 2 seconds
|
||||
end sleeping for 1 seconds
|
||||
end sleeping for 2 seconds
|
||||
```
|
||||
|
||||
As you can see, coroutines do not block each other - the second task starts before the first is finished. This is happening because asyncio.sleep is a coroutine which returns execution to a scheduler until the time will pass. In the next section, we will use coroutine-based tasks to create a game loop.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/
|
||||
|
||||
作者：[Kyrylo Subbotin][a]
|
||||
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://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/
|
||||
[1]: http://snakepit-game.com/
|
||||
[2]: http://snakepit-game.com/
|
||||
[3]: https://docs.python.org/3/library/asyncio.html
|
||||
[4]: https://docs.python.org/3/whatsnew/3.5.html#whatsnew-pep-492
|
||||
[5]: https://docs.python.org/2/library/select.html
|
||||
[6]: http://www.tornadoweb.org/
|
||||
[7]: http://twistedmatrix.com/
|
||||
[8]: http://www.stackless.com/
|
||||
[9]: http://www.eveonline.com/
|
||||
[10]: http://eventlet.net/
|
||||
[11]: http://www.gevent.org/
|
||||
@ -1,320 +0,0 @@
|
||||
wyangsun translating
|
||||
How to build and deploy a Facebook Messenger bot with Python and Flask, a tutorial
|
||||
==========================================================================
|
||||
|
||||
This is my log of how I built a simple Facebook Messenger bot. The functionality is really simple, it’s an echo bot that will just print back to the user what they write.
|
||||
|
||||
This is something akin to the Hello World example for servers, the echo server.
|
||||
|
||||
The goal of the project is not to build the best Messenger bot, but rather to get a feel for what it takes to build a minimal bot and how everything comes together.
|
||||
|
||||
- [Tech Stack][1]
|
||||
- [Bot Architecture][2]
|
||||
- [The Bot Server][3]
|
||||
- [Deploying to Heroku][4]
|
||||
- [Creating the Facebook App][5]
|
||||
- [Conclusion][6]
|
||||
|
||||
### Tech Stack
|
||||
|
||||
The tech stack that was used is:
|
||||
|
||||
- [Heroku][7] for back end hosting. The free-tier is more than enough for a tutorial of this level. The echo bot does not require any sort of data persistence so a database was not used.
|
||||
- [Python][8] was the language of choice. The version that was used is 2.7 however it can easily be ported to Python 3 with minor alterations.
|
||||
- [Flask][9] as the web development framework. It’s a very lightweight framework that’s perfect for small scale projects/microservices.
|
||||
- Finally the [Git][10] version control system was used for code maintenance and to deploy to Heroku.
|
||||
- Worth mentioning: [Virtualenv][11]. This python tool is used to create “environments” clean of python libraries so you can only install the necessary requirements and minimize the app footprint.
|
||||
|
||||
### Bot Architecture
|
||||
|
||||
Messenger bots are constituted by a server that responds to two types of requests:
|
||||
|
||||
- GET requests are being used for authentication. They are sent by Messenger with an authentication code that you register on FB.
|
||||
- POST requests are being used for the actual communication. The typical workflow is that the bot will initiate the communication by sending the POST request with the data of the message sent by the user, we will handle it, send a POST request of our own back. If that one is completed successfully (a 200 OK status is returned) we also respond with a 200 OK code to the initial Messenger request.
|
||||
For this tutorial the app will be hosted on Heroku, which provides a nice and easy interface to deploy apps. As mentioned the free tier will suffice for this tutorial.
|
||||
|
||||
After the app has been deployed and is running, we’ll create a Facebook app and link it to our app so that messenger knows where to send the requests that are meant for our bot.
|
||||
|
||||
### The Bot Server
|
||||
The basic server code was taken from the following [Chatbot][12] project by Github user [hult (Magnus Hult)][13], with a few modifications to the code to only echo messages and a couple bugfixes I came across. This is the final version of the server code:
|
||||
|
||||
```
|
||||
from flask import Flask, request
|
||||
import json
|
||||
import requests
|
||||
|
||||
app = Flask(__name__)
|
||||
|
||||
# This needs to be filled with the Page Access Token that will be provided
|
||||
# by the Facebook App that will be created.
|
||||
PAT = ''
|
||||
|
||||
@app.route('/', methods=['GET'])
|
||||
def handle_verification():
|
||||
print "Handling Verification."
|
||||
if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me':
|
||||
print "Verification successful!"
|
||||
return request.args.get('hub.challenge', '')
|
||||
else:
|
||||
print "Verification failed!"
|
||||
return 'Error, wrong validation token'
|
||||
|
||||
@app.route('/', methods=['POST'])
|
||||
def handle_messages():
|
||||
print "Handling Messages"
|
||||
payload = request.get_data()
|
||||
print payload
|
||||
for sender, message in messaging_events(payload):
|
||||
print "Incoming from %s: %s" % (sender, message)
|
||||
send_message(PAT, sender, message)
|
||||
return "ok"
|
||||
|
||||
def messaging_events(payload):
|
||||
"""Generate tuples of (sender_id, message_text) from the
|
||||
provided payload.
|
||||
"""
|
||||
data = json.loads(payload)
|
||||
messaging_events = data["entry"][0]["messaging"]
|
||||
for event in messaging_events:
|
||||
if "message" in event and "text" in event["message"]:
|
||||
yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape')
|
||||
else:
|
||||
yield event["sender"]["id"], "I can't echo this"
|
||||
|
||||
|
||||
def send_message(token, recipient, text):
|
||||
"""Send the message text to recipient with id recipient.
|
||||
"""
|
||||
|
||||
r = requests.post("https://graph.facebook.com/v2.6/me/messages",
|
||||
params={"access_token": token},
|
||||
data=json.dumps({
|
||||
"recipient": {"id": recipient},
|
||||
"message": {"text": text.decode('unicode_escape')}
|
||||
}),
|
||||
headers={'Content-type': 'application/json'})
|
||||
if r.status_code != requests.codes.ok:
|
||||
print r.text
|
||||
|
||||
if __name__ == '__main__':
|
||||
app.run()
|
||||
```
|
||||
|
||||
Let’s break down the code. The first part is the imports that will be needed:
|
||||
|
||||
```
|
||||
from flask import Flask, request
|
||||
import json
|
||||
import requests
|
||||
```
|
||||
|
||||
Next we define the two functions (using the Flask specific app.route decorators) that will handle the GET and POST requests to our bot.
|
||||
|
||||
```
|
||||
@app.route('/', methods=['GET'])
|
||||
def handle_verification():
|
||||
print "Handling Verification."
|
||||
if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me':
|
||||
print "Verification successful!"
|
||||
return request.args.get('hub.challenge', '')
|
||||
else:
|
||||
print "Verification failed!"
|
||||
return 'Error, wrong validation token'
|
||||
```
|
||||
|
||||
The verify_token object that is being sent by Messenger will be declared by us when we create the Facebook app. We have to validate the one we are being have against itself. Finally we return the “hub.challenge” back to Messenger.
|
||||
|
||||
The function that handles the POST requests is a bit more interesting.
|
||||
|
||||
```
|
||||
@app.route('/', methods=['POST'])
|
||||
def handle_messages():
|
||||
print "Handling Messages"
|
||||
payload = request.get_data()
|
||||
print payload
|
||||
for sender, message in messaging_events(payload):
|
||||
print "Incoming from %s: %s" % (sender, message)
|
||||
send_message(PAT, sender, message)
|
||||
return "ok"
|
||||
```
|
||||
|
||||
When called we grab the massage payload, use function messaging_events to break it down and extract the sender user id and the actual message sent, generating a python iterator that we can loop over. Notice that in each request sent by Messenger it is possible to have more than one messages.
|
||||
|
||||
```
|
||||
def messaging_events(payload):
|
||||
"""Generate tuples of (sender_id, message_text) from the
|
||||
provided payload.
|
||||
"""
|
||||
data = json.loads(payload)
|
||||
messaging_events = data["entry"][0]["messaging"]
|
||||
for event in messaging_events:
|
||||
if "message" in event and "text" in event["message"]:
|
||||
yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape')
|
||||
else:
|
||||
yield event["sender"]["id"], "I can't echo this"
|
||||
```
|
||||
|
||||
While iterating over each message we call the send_message function and we perform the POST request back to Messnger using the Facebook Graph messages API. During this time we still have not responded to the original Messenger request which we are blocking. This can lead to timeouts and 5XX errors.
|
||||
|
||||
The above was spotted during an outage due to a bug I came across, which was occurred when the user was sending emojis which are actual unicode ids, however Python was miss-encoding. We ended up sending back garbage.
|
||||
|
||||
This POST request back to Messenger would never finish, and that in turn would cause 5XX status codes to be returned to the original request, rendering the service unusable.
|
||||
|
||||
This was fixed by escaping the messages with `encode('unicode_escape')` and then just before we sent back the message decode it with `decode('unicode_escape')`.
|
||||
|
||||
```
|
||||
def send_message(token, recipient, text):
|
||||
"""Send the message text to recipient with id recipient.
|
||||
"""
|
||||
|
||||
r = requests.post("https://graph.facebook.com/v2.6/me/messages",
|
||||
params={"access_token": token},
|
||||
data=json.dumps({
|
||||
"recipient": {"id": recipient},
|
||||
"message": {"text": text.decode('unicode_escape')}
|
||||
}),
|
||||
headers={'Content-type': 'application/json'})
|
||||
if r.status_code != requests.codes.ok:
|
||||
print r.text
|
||||
```
|
||||
|
||||
### Deploying to Heroku
|
||||
|
||||
Once the code was built to my liking it was time for the next step.
|
||||
Deploy the app.
|
||||
|
||||
Sure, but how?
|
||||
|
||||
I have deployed apps before to Heroku (mainly Rails) however I was always following a tutorial of some sort, so the configuration has already been created. In this case though I had to start from scratch.
|
||||
|
||||
Fortunately it was the official [Heroku documentation][14] to the rescue. The article explains nicely the bare minimum required for running an app.
|
||||
|
||||
Long story short, what we need besides our code are two files. The first file is the “requirements.txt” file which is a list of of the library dependencies required to run the application.
|
||||
|
||||
The second file required is the “Procfile”. This file is there to inform the Heroku how to run our service. Again the bare minimum needed for this file is the following:
|
||||
|
||||
>web: gunicorn echoserver:app
|
||||
|
||||
The way this will be interpreted by heroku is that our app is started by running the echoserver.py file and the app will be using gunicorn as the web server. The reason we are using an additional webserver is performance related and is explained in the above Heroku documentation:
|
||||
|
||||
>Web applications that process incoming HTTP requests concurrently make much more efficient use of dyno resources than web applications that only process one request at a time. Because of this, we recommend using web servers that support concurrent request processing whenever developing and running production services.
|
||||
|
||||
>The Django and Flask web frameworks feature convenient built-in web servers, but these blocking servers only process a single request at a time. If you deploy with one of these servers on Heroku, your dyno resources will be underutilized and your application will feel unresponsive.
|
||||
|
||||
>Gunicorn is a pure-Python HTTP server for WSGI applications. It allows you to run any Python application concurrently by running multiple Python processes within a single dyno. It provides a perfect balance of performance, flexibility, and configuration simplicity.
|
||||
|
||||
Going back to our “requirements.txt” file let’s see how it binds with the Virtualenv tool that was mentioned.
|
||||
|
||||
At anytime, your developement machine may have a number of python libraries installed. When deploying applications you don’t want to have these libraries loaded as it makes it hard to make out which ones you actually use.
|
||||
|
||||
What Virtualenv does is create a new blank virtual enviroment so that you can only install the libraries that your app requires.
|
||||
|
||||
You can check which libraries are currently installed by running the following command:
|
||||
|
||||
```
|
||||
kostis@KostisMBP ~ $ pip freeze
|
||||
cycler==0.10.0
|
||||
Flask==0.10.1
|
||||
gunicorn==19.6.0
|
||||
itsdangerous==0.24
|
||||
Jinja2==2.8
|
||||
MarkupSafe==0.23
|
||||
matplotlib==1.5.1
|
||||
numpy==1.10.4
|
||||
pyparsing==2.1.0
|
||||
python-dateutil==2.5.0
|
||||
pytz==2015.7
|
||||
requests==2.10.0
|
||||
scipy==0.17.0
|
||||
six==1.10.0
|
||||
virtualenv==15.0.1
|
||||
Werkzeug==0.11.10
|
||||
```
|
||||
|
||||
Note: The pip tool should already be installed on your machine along with Python.
|
||||
|
||||
If not check the [official site][15] for how to install it.
|
||||
|
||||
Now let’s use Virtualenv to create a new blank enviroment. First we create a new folder for our project, and change dir into it:
|
||||
|
||||
```
|
||||
kostis@KostisMBP projects $ mkdir echoserver
|
||||
kostis@KostisMBP projects $ cd echoserver/
|
||||
kostis@KostisMBP echoserver $
|
||||
```
|
||||
|
||||
Now let’s create a new enviroment called echobot. To activate it you run the following source command, and checking with pip freeze we can see that it’s now empty.
|
||||
|
||||
```
|
||||
kostis@KostisMBP echoserver $ virtualenv echobot
|
||||
kostis@KostisMBP echoserver $ source echobot/bin/activate
|
||||
(echobot) kostis@KostisMBP echoserver $ pip freeze
|
||||
(echobot) kostis@KostisMBP echoserver $
|
||||
```
|
||||
|
||||
We can start installing the libraries required. The ones we’ll need are flask, gunicorn, and requests and with them installed we create the requirements.txt file:
|
||||
|
||||
```
|
||||
(echobot) kostis@KostisMBP echoserver $ pip install flask
|
||||
(echobot) kostis@KostisMBP echoserver $ pip install gunicorn
|
||||
(echobot) kostis@KostisMBP echoserver $ pip install requests
|
||||
(echobot) kostis@KostisMBP echoserver $ pip freeze
|
||||
click==6.6
|
||||
Flask==0.11
|
||||
gunicorn==19.6.0
|
||||
itsdangerous==0.24
|
||||
Jinja2==2.8
|
||||
MarkupSafe==0.23
|
||||
requests==2.10.0
|
||||
Werkzeug==0.11.10
|
||||
(echobot) kostis@KostisMBP echoserver $ pip freeze > requirements.txt
|
||||
```
|
||||
|
||||
After all the above have been run, we create the echoserver.py file with the python code and the Procfile with the command that was mentioned, and we should end up with the following files/folders:
|
||||
|
||||
```
|
||||
(echobot) kostis@KostisMBP echoserver $ ls
|
||||
Procfile echobot echoserver.py requirements.txt
|
||||
```
|
||||
|
||||
We are now ready to upload to Heroku. We need to do two things. The first is to install the Heroku toolbet if it’s not already installed on your system (go to [Heroku][16] for details). The second is to create a new Heroku app through the [web interface][17].
|
||||
|
||||
Click on the big plus sign on the top right and select “Create new app”.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/
|
||||
|
||||
作者：[Konstantinos Tsaprailis][a]
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://github.com/kostistsaprailis
|
||||
[1]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#tech-stack
|
||||
[2]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#bot-architecture
|
||||
[3]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#the-bot-server
|
||||
[4]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#deploying-to-heroku
|
||||
[5]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#creating-the-facebook-app
|
||||
[6]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#conclusion
|
||||
[7]: https://www.heroku.com
|
||||
[8]: https://www.python.org
|
||||
[9]: http://flask.pocoo.org
|
||||
[10]: https://git-scm.com
|
||||
[11]: https://virtualenv.pypa.io/en/stable
|
||||
[12]: https://github.com/hult/facebook-chatbot-python
|
||||
[13]: https://github.com/hult
|
||||
[14]: https://devcenter.heroku.com/articles/python-gunicorn
|
||||
[15]: https://pip.pypa.io/en/stable/installing
|
||||
[16]: https://toolbelt.heroku.com
|
||||
[17]: https://dashboard.heroku.com/apps
|
||||
|
||||
|
||||
@ -0,0 +1,73 @@
|
||||
Web Service Efficiency at Instagram with Python
|
||||
===============================================
|
||||
|
||||
Instagram currently features the world’s largest deployment of the Django web framework, which is written entirely in Python. We initially chose to use Python because of its reputation for simplicity and practicality, which aligns well with our philosophy of “do the simple thing first.” But simplicity can come with a tradeoff: efficiency. Instagram has doubled in size over the last two years and recently crossed 500 million users, so there is a strong need to maximize web service efficiency so that our platform can continue to scale smoothly. In the past year we’ve made our efficiency program a priority, and over the last six months we’ve been able to maintain our user growth without adding new capacity to our Django tiers. In this post, we’ll share some of the tools we built and how we use them to optimize our daily deployment flow.
|
||||
|
||||
### Why Efficiency?
|
||||
|
||||
Instagram, like all software, is limited by physical constraints like servers and datacenter power. With these constraints in mind, there are two main goals we want to achieve with our efficiency program:
|
||||
|
||||
1. Instagram should be able to serve traffic normally with continuous code rollouts in the case of lost capacity in one data center region, due to natural disaster, regional network issues, etc.
|
||||
2. Instagram should be able to freely roll out new products and features without being blocked by capacity.
|
||||
|
||||
To meet these goals, we realized we needed to persistently monitor our system and battle regression.
|
||||
|
||||
### Defining Efficiency
|
||||
|
||||
Web services are usually bottlenecked by available CPU time on each server. Efficiency in this context means using the same amount of CPU resources to do more work, a.k.a, processing more user requests per second (RPS). As we look for ways to optimize, our first challenge is trying to quantify our current efficiency. Up to this point, we were approximating efficiency using ‘Average CPU time per requests,’ but there were two inherent limitations to using this metric:
|
||||
|
||||
1. Diversity of devices. Using CPU time for measuring CPU resources is not ideal because it is affected by both CPU models and CPU loads.
|
||||
2. Request impacts data. Measuring CPU resource per request is not ideal because adding and removing light or heavy requests would also impact the efficiency metric using the per-requests measurement.
|
||||
|
||||
Compared to CPU time, CPU instruction is a better metric, as it reports the same numbers regardless of CPU models and CPU loads for the same request. Instead of linking all our data to each user request, we chose to use a ‘per active user’ metric. We eventually landed on measuring efficiency by using ‘CPU instruction per active user during peak minute.’ With our new metric established, our next step was to learn more about our regressions by profiling Django.
|
||||
|
||||
### Profiling the Django Service
|
||||
|
||||
There are two major questions we want to answer by profiling our Django web service:
|
||||
|
||||
1. Does a CPU regression happen?
|
||||
2. What causes the CPU regression and how do we fix it?
|
||||
|
||||
To answer the first question, we need to track the CPU-instruction-per-active-user metric. If this metric increases, we know a CPU regression has occurred.
|
||||
|
||||
The tool we built for this purpose is called Dynostats. Dynostats utilizes Django middleware to sample user requests by a certain rate, recording key efficiency and performance metrics such as the total CPU instructions, end to end requests latency, time spent on accessing memcache and database services, etc. On the other hand, each request has multiple metadata that we can use for aggregation, such as the endpoint name, the HTTP return code of the request, the server name that serves this request, and the latest commit hash on the request. Having two aspects for a single request record is especially powerful because we can slice and dice on various dimensions that help us narrow down the cause of any CPU regression. For example, we can aggregate all requests by their endpoint names as shown in the time series chart below, where it is very obvious to spot if any regression happens on a specific endpoint.
|
||||
|
||||
|
||||
|
||||
CPU instructions matter for measuring efficiency — and they’re also the hardest to get. Python does not have common libraries that support direct access to the CPU hardware counters (CPU hardware counters are the CPU registers that can be programmed to measure performance metrics, such as CPU instructions). Linux kernel, on the other hand, provides the perf_event_open system call. Bridging through Python ctypes enables us to call the syscall function in standard C library, which also provides C compatible data types for programming the hardware counters and reading data from them.
|
||||
|
||||
With Dynostats, we can already find CPU regressions and dig into the cause of the CPU regression, such as which endpoint gets impacted most, who committed the changes that actually cause the CPU regression, etc. However, when a developer is notified that their changes have caused a CPU regression, they usually have a hard time finding the problem. If it was obvious, the regression probably wouldn’t have been committed in the first place!
|
||||
|
||||
That’s why we needed a Python profiler that the developer can use to find the root cause of the regression (once Dynostats identifies it). Instead of starting from scratch, we decided to make slight alterations to cProfile, a readily available Python profiler. The cProfile module normally provides a set of statistics describing how long and how often various parts of a program were executed. Instead of measuring in time, we took cProfile and replaced the timer with a CPU instruction counter that reads from hardware counters. The data is created at the end of the sampled requests and sent to some data pipelines. We also send metadata similar to what we have in Dynostats, such as server name, cluster, region, endpoint name, etc.
|
||||
On the other side of the data pipeline, we created a tailer to consume the data. The main functionality of the tailer is to parse the cProfile stats data and create entities that represent Python function-level CPU instructions. By doing so, we can aggregate CPU instructions by Python functions, making it easier to tell which functions contribute to CPU regression.
|
||||
|
||||
### Monitoring and Alerting Mechanism
|
||||
|
||||
At Instagram, we [deploy our backend 30–50 times a day][1]. Any one of these deployments can contain troublesome CPU regressions. Since each rollout usually includes at least one diff, it is easy to identify the cause of any regression. Our efficiency monitoring mechanism includes scanning the CPU instruction in Dynostats before and after each rollout, and sending out alerts when the change exceeds a certain threshold. For the CPU regressions happening over longer periods of time, we also have a detector to scan daily and weekly changes for the most heavily loaded endpoints.
|
||||
|
||||
Deploying new changes is not the only thing that can trigger a CPU regression. In many cases, the new features or new code paths are controlled by global environment variables (GEV). There are very common practices for rolling out new features to a subset of users on a planned schedule. We added this information as extra metadata fields for each request in Dynostats and cProfile stats data. Grouping requests by those fields reveal possible CPU regressions caused by turning the GEVs. This enables us to catch CPU regressions before they can impact performance.
|
||||
|
||||
### What’s Next?
|
||||
|
||||
Dynostats and our customized cProfile, along with the monitoring and alerting mechanism we’ve built to support them, can effectively identify the culprit for most CPU regressions. These developments have helped us recover more than 50% of unnecessary CPU regressions, which would have otherwise gone unnoticed.
|
||||
|
||||
There are still areas where we can improve and make it easier to embed into Instagram’s daily deployment flow:
|
||||
|
||||
1. The CPU instruction metric is supposed to be more stable than other metrics like CPU time, but we still observe variances that make our alerting noisy. Keeping signal:noise ratio reasonably low is important so that developers can focus on the real regressions. This could be improved by introducing the concept of confidence intervals and only alarm when it is high. For different endpoints, the threshold of variation could also be set differently.
|
||||
2. One limitation for detecting CPU regressions by GEV change is that we have to manually enable the logging of those comparisons in Dynostats. As the number of GEVs increases and more features are developed, this wont scale well. Instead, we could leverage an automatic framework that schedules the logging of these comparisons and iterates through all GEVs, and send alerts when regressions are detected.
|
||||
3. cProfile needs some enhancement to handle wrapper functions and their children functions better.
|
||||
|
||||
With the work we’ve put into building the efficiency framework for Instagram’s web service, we are confident that we will keep scaling our service infrastructure using Python. We’ve also started to invest more into the Python language itself, and are beginning to explore moving our Python from version 2 to 3. We will continue to explore this and more experiments to keep improving both infrastructure and developer efficiency, and look forward to sharing more soon.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://engineering.instagram.com/web-service-efficiency-at-instagram-with-python-4976d078e366#.tiakuoi4p
|
||||
|
||||
作者：[Min Ni][a]
|
||||
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://engineering.instagram.com/@InstagramEng?source=post_header_lockup
|
||||
[1]: https://engineering.instagram.com/continuous-deployment-at-instagram-1e18548f01d1#.p5adp7kcz
|
||||
@ -1,3 +1,4 @@
|
||||
Translating by ivo-wang
|
||||
Microfluidic cooling may prevent the demise of Moore's Law
|
||||
============================================================
|
||||
|
||||
|
||||
@ -0,0 +1,327 @@
|
||||
Excel “Filter and Edit” - Demonstrated in Pandas
|
||||
==================================================
|
||||
|
||||
|
||||
|
||||
### Introduction
|
||||
|
||||
I have heard from various people that my [previous][1] [articles][2] on common Excel tasks in pandas were useful in helping new pandas users translate Excel processes into equivalent pandas code. This article will continue that tradition by illustrating various pandas indexing examples using Excel’s Filter function as a model for understanding the process.
|
||||
|
||||
One of the first things most new pandas users learn is basic data filtering. Despite working with pandas over the past few months, I recently realized that there was another benefit to the pandas filtering approach that I was not using in my day to day work. Namely that you can filter on a given set of columns but update another set of columns using a simplified pandas syntax. This is similar to what I’ll call the “Filter and Edit” process in Excel.
|
||||
|
||||
This article will walk through some examples of filtering a pandas DataFrame and updating the data based on various criteria. Along the way, I will explain some more about panda’s indexing and how to use indexing methods such as .loc , .ix and .iloc to quickly and easily update a subset of data based on simple or complex criteria.
|
||||
|
||||
### Excel: “Filter and Edit”
|
||||
|
||||
Outside of the Pivot Table, one of the top go-to tools in Excel is the Filter. This simple tool allows a user to quickly filter and sort the data by various numeric, text and formatting criteria. Here is a basic screenshot of some sample data with data filtered by several different criteria:
|
||||
|
||||
|
||||
|
||||
The Filter process is intuitive and is easy to grasp for even the most novice Excel user. I have also noticed that people will use this feature to select rows of data, then update additional columns based on the row criteria. The example below shows what I’m describing:
|
||||
|
||||
|
||||
|
||||
In the example, I have filtered the data on Account Number, SKU and Unit Price. Then I manually added a Commission_Rate column and typed in 0.01 in each cell. The benefit to this approach is that it is easy to understand and can help someone manage relatively complex data without writing long Excel formulas or getting into VBA. The downside of this approach is that it is not repeatable and can be difficult for someone from the outside to understand which criteria were used for any filter.
|
||||
|
||||
For instance, if you look at the screenshot about, there is no obvious way to tell what is filtered without looking at each column. Fortunately, we can do something very similar in pandas. Not surprisingly, it is easy in pandas to execute this “Filter and Edit” model with simple and clean code.
|
||||
|
||||
### Boolean Indexing
|
||||
|
||||
Now that you have a feel for the problem, I want to step through some details of boolean indexing in pandas. This is an important concept to understand if you want to understand pandas’ [Indexing and Selecting of Data][3] in the most broad sense. This idea may seem a little complex to the new pandas user (and maybe too basic for experienced users) but I think it is important to take some time and understand it. If you grasp this concept, the basic process of working with data in pandas will be more straightforward.
|
||||
|
||||
Pandas supports indexing (or selecting data) by using labels, position based integers or a list of boolean values (True/False). Using a list of boolean values to select a row is called boolean indexing and will be the focus of the rest of this article.
|
||||
|
||||
I find that my pandas workflow tends to focus mostly on using lists of boolean values for selecting my data. In other words, when I create pandas DataFrames, I tend to keep the default index in the DataFrame. Therefore the index is not really meaningful on its own and not straightforward for selecting data.
|
||||
|
||||
>Key Point
|
||||
> Boolean indexing is one (of several) powerful and useful ways of selecting rows of data in pandas.
|
||||
|
||||
Let’s look at some example DataFrames to help clarify the what a boolean index in pandas does.
|
||||
|
||||
First, we will create a very small DataFrame purely from a python list and use it to show how boolean indexing works.
|
||||
|
||||
```
|
||||
import pandas as pd
|
||||
sales = [('account', ['Jones LLC', 'Alpha Co', 'Blue Inc', 'Mega Corp']),
|
||||
('Total Sales', [150, 200, 75, 300]),
|
||||
('Country', ['US', 'UK', 'US', 'US'])]
|
||||
df = pd.DataFrame.from_items(sales)
|
||||
```
|
||||
|
||||
|account |Total Sales |Country
|
||||
:--|:-- |:-- |:
|
||||
0 |Jones LLC |150 |US
|
||||
1 |Alpha Co |200 |UK
|
||||
2 |Blue Inc |75 |US
|
||||
3 |Mega Corp |300 |US
|
||||
|
||||
Notice how the values 0-3, get automatically assigned to the rows? Those are the indices and they are not particularly meaningful in this data set but are useful to pandas and are important to understand for other use cases not described below.
|
||||
|
||||
When we refer to boolean indexing, we simply mean that we can pass in a list of True or False values representing each row we want to view.
|
||||
|
||||
In this case, if we want to view the data for Jones LLC, Blue Inc and Mega Corp, we can see that the True False list would look like this:
|
||||
|
||||
```
|
||||
indices = [True, False, True, True]
|
||||
```
|
||||
|
||||
It should be no surprise, that you can pass this list to your DataFrame and it will only display the rows where our value is True :
|
||||
|
||||
```
|
||||
df[indices]
|
||||
```
|
||||
|
||||
|account |Total Sales |Country
|
||||
:--|:--|:--|:--
|
||||
0 |Jones LLC |150 |US
|
||||
2 |Blue Inc |75 |US
|
||||
3 |Mega Corp |300 |US
|
||||
|
||||
Here is a visual of what just happened:
|
||||
|
||||
|
||||
|
||||
This manual list creation of the index works but obviously is not scaleable or very useful for anything more than a trivial data set. Fortunately pandas makes it very easy to create these boolean indexes using a simple query language that should be familiar to someone that has used python (or any language for that matter).
|
||||
|
||||
For an example, let’s look at all sales lines from the US. If we execute a python expression based on the Country column:
|
||||
|
||||
```
|
||||
df.Country == 'US'
|
||||
```
|
||||
|
||||
```
|
||||
0 True
|
||||
1 False
|
||||
2 True
|
||||
3 True
|
||||
Name: Country, dtype: bool
|
||||
```
|
||||
|
||||
The example shows how pandas will take your traditional python logic, apply it to a DataFrame and return a list of boolean values. This list of boolean values can then be passed to the DataFrame to get the corresponding rows of data.
|
||||
|
||||
In real code, you would not do this two step process. The shorthand method for doing this would typically look like this:
|
||||
|
||||
```
|
||||
df[df["Country"] == 'US']
|
||||
```
|
||||
|
||||
|account |Total Sales |Country
|
||||
:--|:--|:--|:--
|
||||
0 |Jones LLC |150| US
|
||||
2 |Blue Inc |75 |US
|
||||
3 |Mega Corp| 300| US
|
||||
|
||||
While this concept is simple, you can write fairly complex logic to filter your data using the power of python.
|
||||
|
||||
>Key Point
|
||||
>In this example, `df[df.Country == 'US']` is equivalent to `df[df["Country"] == 'US']` The ‘.’ notation is cleaner but will not work when there are spaces in your column names.
|
||||
|
||||
### Selecting the Columns
|
||||
|
||||
Now that we have figured out how to select rows of data, how can we control which columns to display? In the example above, there’s no obvious way to do that. Pandas can support this use case using three types of location based indexing: .loc , iloc , and .ix . These functions also allow us to select columns in addition to the row selection we have seen so far.
|
||||
|
||||
There is a lot of confusion about when to use .loc , iloc , or .ix . The quick summary of the difference is that:
|
||||
|
||||
- .loc is used for label indexing
|
||||
- .iloc is used for position based integers
|
||||
- .ix is a shortcut that will try to use labels (like .loc ) but will fall back to position based integers (like .iloc )
|
||||
|
||||
So, the question is, which one should I use? I will profess that I get tripped up some times on this one too. I have found that I use .loc most frequently. Mainly because my data does not lend itself to meaningful position based indexing (in other words, I rarely find myself needing .iloc ) so I stick with .loc .
|
||||
|
||||
To be fair each of these methods do have their place and are useful in many situations. One area in particular is when dealing with MultiIndex DataFrames. I will not cover that topic in this article - maybe in a future post.
|
||||
|
||||
Now that we have covered this topic, let’s show how to filter a DataFrame on values in a row and select specific columns to display.
|
||||
|
||||
Continuing with our example, what if we just want to show the account names that correspond to our index? Using .loc it is simple:
|
||||
|
||||
```
|
||||
df.loc[[True, True, False, True], "account"]
|
||||
```
|
||||
|
||||
```
|
||||
1 Alpha Co
|
||||
2 Blue Inc
|
||||
3 Mega Corp
|
||||
Name: account, dtype: object
|
||||
```
|
||||
|
||||
If you would like to see multiple columns, just pass a list:
|
||||
|
||||
```
|
||||
df.loc[[True, True, False, True], ["account", "Country"]]
|
||||
```
|
||||
|
||||
| account |Country
|
||||
:--|:--|:--
|
||||
0 |Jones LLC| US
|
||||
1 |Alpha Co |UK
|
||||
3 |Mega Corp |US
|
||||
|
||||
The real power is when you create more complex queries on your data. In this case, let’s show all account names and Countries where sales > 200:
|
||||
|
||||
```
|
||||
df.loc[df["Total Sales"] > 200, ["account", "Country"]]
|
||||
```
|
||||
|
||||
|account| Country
|
||||
:--|:--|:--
|
||||
3 |Mega Corp| US
|
||||
|
||||
This process can be thought of somewhat equivalent to Excel’s Filter we discussed above. You have the added benefit that you can also limit the number of columns you retrieve, not just the rows.
|
||||
|
||||
### Editing Columns
|
||||
|
||||
All of this is good background but where this process really shines is when you use a similar approach for updating one or more columns based on a row selection.
|
||||
|
||||
For one simple example, let’s add a commission rate column to our data:
|
||||
|
||||
```
|
||||
df["rate"] = 0.02
|
||||
```
|
||||
|
||||
| account |Total Sales| Country |rate
|
||||
:--|:--|:--|:--|:--
|
||||
0 |Jones LLC |150 |US |0.02
|
||||
1 |Alpha Co |200 |UK |0.02
|
||||
2 |Blue Inc |75 |US |0.02
|
||||
3 |Mega Corp |300 |US |0.02
|
||||
|
||||
Let’s say that if you sold more than 100, your rate is 5%. The basic process is to setup a boolean index to select the columns, then assign the value to the rate column:
|
||||
|
||||
```
|
||||
df.loc[df["Total Sales"] > 100, ["rate"]] = .05
|
||||
```
|
||||
|
||||
| account |Total Sales| Country| rate
|
||||
:--|:--|:--|:--|:--
|
||||
0 |Jones LLC |150| US| 0.05
|
||||
1 |Alpha Co |200 |UK |0.05
|
||||
2| Blue Inc |75| US |0.02
|
||||
3 |Mega Corp |300| US| 0.05
|
||||
|
||||
Hopefully if you stepped through this article, this will make sense and that it will help you understand how this syntax works. Now you have the fundamentals of the “Filter and Edit” approach. The final section will show this process in a little more detail in Excel and pandas.
|
||||
|
||||
### Bringing It All Together
|
||||
|
||||
For the final example, we will create a simple commissions calculator using the following rules:
|
||||
|
||||
- All commissions calculated at the transaction level
|
||||
- Base commission on all sales is 2%
|
||||
- All shirts will get a commission of 2.5%
|
||||
- A special program is going on where selling > 10 belts in one transaction gets 4% commission
|
||||
- There is a special bonus of $250 plus a 4.5% commission for all shoe sales > $1000 in a single transaction
|
||||
|
||||
In order to do this in Excel, using the Filter and edit approach:
|
||||
|
||||
- Add a commission column with 2%
|
||||
- Add a bonus column of $0
|
||||
- Filter on shirts and change the vale to 2.5%
|
||||
- Clear the filter
|
||||
- Filter for belts and quantity > 10 and change the value to 4%
|
||||
- Clear the filter
|
||||
- Filter for shoes > $1000 and add commission and bonus values of 4.5% and $250 respectively
|
||||
|
||||
I am not going to show a screen shot of each step but here is the last filter:
|
||||
|
||||
|
||||
|
||||
This approach is simple enough to manipulate in Excel but it is not very repeatable nor audit-able. There are certainly other approaches to accomplish this in Excel - such as formulas or VBA. However, this Filter and Edit approach is common and is illustrative of the pandas logic.
|
||||
|
||||
Now, let’s walk through the whole example in pandas.
|
||||
|
||||
First, read in the [Excel file][4] and add a column with the 2% default rate:
|
||||
|
||||
```
|
||||
import pandas as pd
|
||||
df = pd.read_excel("https://github.com/chris1610/pbpython/blob/master/data/sample-sales-reps.xlsx?raw=true")
|
||||
df["commission"] = .02
|
||||
df.head()
|
||||
```
|
||||
|
||||
| account number| customer name| sales rep| sku |category |quantity |unit price| ext price| date| commission
|
||||
:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--
|
||||
0 |680916 |Mueller and Sons |Loring Predovic |GP-14407 | Belt |19 |88.49 |1681.31 |2015-11-17 05:58:34| 0.02
|
||||
1 |680916 |Mueller and Sons |Loring Predovic |FI-01804| Shirt |3| 78.07| 234.21 |2016-02-13 04:04:11 |0.02
|
||||
2 |530925 |Purdy and Sons| Teagan O’Keefe |EO-54210 |Shirt |19 |30.21 |573.99 |2015-08-11 12:44:38 |0.02
|
||||
3 |14406| Harber, Lubowitz and Fahey| Esequiel Schinner| NZ-99565| Shirt| 12| 90.29 |1083.48 |2016-01-23 02:15:50 |0.02
|
||||
4 |398620| Brekke Ltd |Esequiel Schinner |NZ-99565 |Shirt |5| 72.64 |363.20 |2015-08-10 07:16:03 |0.02
|
||||
|
||||
The next commission rule is for all shirts to get 2.5% and Belt sales > 10 get a 4% rate:
|
||||
|
||||
```
|
||||
df.loc[df["category"] == "Shirt", ["commission"]] = .025
|
||||
df.loc[(df["category"] == "Belt") & (df["quantity"] >= 10), ["commission"]] = .04
|
||||
df.head()
|
||||
```
|
||||
|
||||
| account number |customer name |sales rep| sku |category |quantity| unit price| ext price |date |commission
|
||||
:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--
|
||||
0 |680916| Mueller and Sons| Loring Predovic| GP-14407| Belt| 19 |88.49| 1681.31 |2015-11-17 05:58:34| 0.040
|
||||
1 |680916| Mueller and Sons| Loring Predovic| FI-01804| Shirt |3 |78.07 |234.21| 2016-02-13 04:04:11 |0.025
|
||||
2 |530925 |Purdy and Sons |Teagan O’Keefe| EO-54210 |Shirt| 19 |30.21 |573.99 |2015-08-11 12:44:38| 0.025
|
||||
3 |14406| Harber, Lubowitz and Fahey| Esequiel Schinner| NZ-99565| Shirt| 12| 90.29| 1083.48| 2016-01-23 02:15:50 |0.025
|
||||
4 |398620| Brekke Ltd| Esequiel Schinner| NZ-99565| Shirt| 5 |72.64 |363.20| 2015-08-10 07:16:03 |0.025
|
||||
|
||||
The final commission rule is to add the special bonus:
|
||||
|
||||
```
|
||||
df["bonus"] = 0
|
||||
df.loc[(df["category"] == "Shoes") & (df["ext price"] >= 1000 ), ["bonus", "commission"]] = 250, 0.045
|
||||
|
||||
# Display a sample of rows that show this bonus
|
||||
df.ix[3:7]
|
||||
```
|
||||
|
||||
| account number| customer name |sales rep| sku |category| quantity| unit price| ext price| date| commission| bonus
|
||||
:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--
|
||||
3| 14406| Harber, Lubowitz and Fahey| Esequiel Schinner| NZ-99565| Shirt |12 |90.29| 1083.48 |2016-01-23 02:15:50 |0.025 |0
|
||||
4| 398620| Brekke Ltd| Esequiel Schinner |NZ-99565| Shirt| 5| 72.64| 363.20| 2015-08-10 07:16:03| 0.025| 0
|
||||
5| 282122| Connelly, Abshire and Von Beth| Skiles| GJ-90272| Shoes| 20| 96.62| 1932.40 |2016-03-17 10:19:05 |0.045 |250
|
||||
6 |398620 |Brekke Ltd| Esequiel Schinner |DU-87462 |Shirt| 10| 67.64 |676.40| 2015-11-25 22:05:36| 0.025| 0
|
||||
7| 218667| Jaskolski-O’Hara| Trish Deckow| DU-87462| Shirt |11| 91.86| 1010.46 |2016-04-24 15:05:58| 0.025| 0
|
||||
|
||||
In order to do the commissions calculation:
|
||||
|
||||
```
|
||||
# Calculate the compensation for each row
|
||||
df["comp"] = df["commission"] * df["ext price"] + df["bonus"]
|
||||
|
||||
# Summarize and round the results by sales rep
|
||||
df.groupby(["sales rep"])["comp"].sum().round(2)
|
||||
```
|
||||
|
||||
```
|
||||
sales rep
|
||||
Ansley Cummings 2169.76
|
||||
Beth Skiles 3028.60
|
||||
Esequiel Schinner 10451.21
|
||||
Loring Predovic 10108.60
|
||||
Shannen Hudson 5275.66
|
||||
Teagan O'Keefe 7989.52
|
||||
Trish Deckow 5807.74
|
||||
Name: comp, dtype: float64
|
||||
```
|
||||
|
||||
If you are interested, an example notebook is hosted on [github][5].
|
||||
|
||||
### Conclusion
|
||||
|
||||
Thanks for reading through the article. I find that one of the biggest challenges for new users in learning how to use pandas is figuring out how to use their Excel-based knowledge to build an equivalent pandas-based solution. In many cases the pandas solution is going to be more robust, faster, easier to audit and more powerful. However, the learning curve can take some time. I hope that this example showing how to solve a problem using Excel’s Filter tool will be a useful guide for those just starting on this pandas journey. Good luck!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://pbpython.com/excel-filter-edit.html
|
||||
|
||||
作者：[Chris Moffitt ][a]
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: http://pbpython.com/author/chris-moffitt.html
|
||||
[1]: http://pbpython.com/excel-pandas-comp.html
|
||||
[2]: http://pbpython.com/excel-pandas-comp-2.html
|
||||
[3]: http://pandas.pydata.org/pandas-docs/stable/indexing.html
|
||||
[4]: https://github.com/chris1610/pbpython/blob/master/data/sample-sales-reps.xlsx?raw=true
|
||||
[5]: https://github.com/chris1610/pbpython/blob/master/notebooks/Commissions-Example.ipynb
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
Translating by cposture 2016-07-29
|
||||
An Introduction to Mocking in Python
|
||||
=====================================
|
||||
|
||||
|
||||
@ -1,106 +0,0 @@
|
||||
Container technologies in Fedora: systemd-nspawn
|
||||
===
|
||||
|
||||
Welcome to the “Container technologies in Fedora” series! This is the first article in a series of articles that will explain how you can use the various container technologies available in Fedora. This first article will deal with `systemd-nspawn`.
|
||||
|
||||
### What is a container?
|
||||
|
||||
A container is a user-space instance which can be used to run a program or an operating system in isolation from the system hosting the container (called the host system). The idea is very similar to a `chroot` or a [virtual machine][1]. The processes running in a container are managed by the same kernel as the host operating system, but they are isolated from the host file system, and from the other processes.
|
||||
|
||||
|
||||
### What is systemd-nspawn?
|
||||
|
||||
The systemd project considers container technologies as something that should fundamentally be part of the desktop and that should integrate with the rest of the user’s systems. To this end, systemd provides `systemd-nspawn`, a tool which is able to create containers using various Linux technologies. It also provides some container management tools.
|
||||
|
||||
In many ways, `systemd-nspawn` is similar to `chroot`, but is much more powerful. It virtualizes the file system, process tree, and inter-process communication of the guest system. Much of its appeal lies in the fact that it provides a number of tools, such as `machinectl`, for managing containers. Containers run by `systemd-nspawn` will integrate with the systemd components running on the host system. As an example, journal entries can be logged from a container in the host system’s journal.
|
||||
|
||||
In Fedora 24, `systemd-nspawn` has been split out from the systemd package, so you’ll need to install the `systemd-container` package. As usual, you can do that with a `dnf install systemd-container`.
|
||||
|
||||
### Creating the container
|
||||
|
||||
Creating a container with `systemd-nspawn` is easy. Let’s say you have an application made for Debian, and it doesn’t run well anywhere else. That’s not a problem, we can make a container! To set up a container with the latest version of Debian (at this point in time, Jessie), you need to pick a directory to set up your system in. I’ll be using `~/DebianJessie` for now.
|
||||
|
||||
Once the directory has been created, you need to run `debootstrap`, which you can install from the Fedora repositories. For Debian Jessie, you run the following command to initialize a Debian file system.
|
||||
|
||||
```
|
||||
$ debootstrap --arch=amd64 stable ~/DebianJessie
|
||||
```
|
||||
|
||||
This assumes your architecture is x86_64. If it isn’t, you must change `amd64` to the name of your architecture. You can find your machine’s architecture with `uname -m`.
|
||||
|
||||
Once your root directory is set up, you will start your container with the following command.
|
||||
|
||||
```
|
||||
$ systemd-nspawn -bD ~/DebianJessie
|
||||
```
|
||||
|
||||
You’ll be up and running within seconds. You’ll notice something as soon as you try to log in: you can’t use any accounts on your system. This is because systemd-nspawn virtualizes users. The fix is simple: remove -b from the previous command. You’ll boot directly to the root shell in the container. From there, you can just use passwd to set a password for root, or you can use adduser to add a new user. As soon as you’re done with that, go ahead and put the -b flag back. You’ll boot to the familiar login console and you log in with the credentials you set.
|
||||
|
||||
All of this applies for any distribution you would want to run in the container, but you need to create the system using the correct package manager. For Fedora, you would use DNF instead of debootstrap. To set up a minimal Fedora system, you can run the following command, replacing the absolute path with wherever you want the container to be.
|
||||
|
||||
```
|
||||
$ sudo dnf --releasever=24 --installroot=/absolute/path/ install systemd passwd dnf fedora-release
|
||||
```
|
||||
|
||||
|
||||
|
||||
### Setting up the network
|
||||
|
||||
You’ll notice an issue if you attempt to start a service that binds to a port currently in use on your host system. Your container is using the same network interface. Luckily, `systemd-nspawn` provides several ways to achieve separate networking from the host machine.
|
||||
|
||||
#### Local networking
|
||||
|
||||
The first method uses the `--private-network` flag, which only creates a loopback device by default. This is ideal for environments where you don’t need networking, such as build systems and other continuous integration systems.
|
||||
|
||||
#### Multiple networking interfaces
|
||||
|
||||
If you have multiple network devices, you can give one to the container with the `--network-interface` flag. To give `eno1` to my container, I would add the flag `--network-interface=eno1`. While an interface is assigned to a container, the host can’t use it at the same time. When the container is completely shut down, it will be available to the host again.
|
||||
|
||||
#### Sharing network interfaces
|
||||
|
||||
For those of us who don’t have spare network devices, there are other options for providing access to the container. One of those is the `--port` flag. This forwards a port on the container to the host. The format is `protocol:host:container`, where protocol is either `tcp` or `udp`, `host` is a valid port number on the host, and `container` is a valid port on the container. You can omit the protocol and specify only `host:container`. I often use something similar to `--port=2222:22`.
|
||||
|
||||
You can enable complete, host-only networking with the `--network-veth` flag, which creates a virtual Ethernet interface between the host and the container. You can also bridge two connections with `--network-bridge`.
|
||||
|
||||
### Using systemd components
|
||||
|
||||
If the system in your container has D-Bus, you can use systemd’s provided utilities to control and monitor your container. Debian doesn’t include dbus in the base install. If you want to use it with Debian Jessie, you’ll want to run `apt install dbus`.
|
||||
|
||||
#### machinectl
|
||||
|
||||
To easily manage containers, systemd provides the machinectl utility. Using machinectl, you can log in to a container with machinectl login name, check the status with machinectl status name, reboot with machinectl reboot name, or power it off with machinectl poweroff name.
|
||||
|
||||
### Other systemd commands
|
||||
|
||||
Most systemd commands, such as journalctl, systemd-analyze, and systemctl, support containers with the `--machine` option. For example, if you want to see the journals of a container named “foobar”, you can use journalctl `--machine=foobar`. You can also see the status of a service running in this container with `systemctl --machine=foobar` status service.
|
||||
|
||||
|
||||
|
||||
### Working with SELinux
|
||||
|
||||
If you’re running with SELinux enforcing (the default in Fedora), you’ll need to set the SELinux context for your container. To do that, you need to run the following two commands on the host system.
|
||||
|
||||
```
|
||||
$ semanage fcontext -a -t svirt_sandbox_file_t "/path/to/container(/.*)?"
|
||||
$ restorecon -R /path/to/container/
|
||||
```
|
||||
|
||||
Make sure you replace “/path/to/container” with the path to your container. For my container, “DebianJessie”, I would run the following:
|
||||
|
||||
```
|
||||
$ semanage fcontext -a -t svirt_sandbox_file_t "/home/johnmh/DebianJessie(/.*)?"
|
||||
$ restorecon -R /home/johnmh/DebianJessie/
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://linoxide.com/linux-how-to/set-nginx-reverse-proxy-centos-7-cpanel/
|
||||
|
||||
作者：[John M. Harris, Jr.][a]
|
||||
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]: http://linoxide.com/linux-how-to/set-nginx-reverse-proxy-centos-7-cpanel/
|
||||
[1]: https://en.wikipedia.org/wiki/Virtual_machine
|
||||
@ -1,124 +0,0 @@
|
||||
Johnny-Liao translating...
|
||||
|
||||
Advanced Image Processing with Python
|
||||
======================================
|
||||
|
||||
|
||||
|
||||
Building an image processing search engine is no easy task. There are several concepts, tools, ideas and technologies that go into it. One of the major image-processing concepts is reverse image querying (RIQ) or reverse image search. Google, Cloudera, Sumo Logic and Birst are among the top organizations to use reverse image search. Great for analyzing images and making use of mined data, RIQ provides a very good insight into analytics.
|
||||
|
||||
### Top Companies and Reverse Image Search
|
||||
|
||||
There are many top tech companies that are using RIQ to best effect. For example, Pinterest first brought in visual search in 2014. It subsequently released a white paper in 2015, revealing the architecture. Reverse image search enabled Pinterest to obtain visual features from fashion objects and display similar product recommendations.
|
||||
|
||||
As is generally known, Google images uses reverse image search allowing users to upload an image and then search for connected images. The submitted image is analyzed and a mathematical model made out of it, by advanced algorithm use. The image is then compared with innumerable others in the Google databases before results are matched and similar results obtained.
|
||||
|
||||
**Here is a graph representation from the OpenCV 2.4.9 Features Comparison Report:**
|
||||
|
||||
|
||||
|
||||
### Algorithms & Python Libraries
|
||||
|
||||
Before we get down to the workings of it, let us rush through the main elements that make building an image processing search engine with Python possible:
|
||||
|
||||
### Patented Algorithms
|
||||
|
||||
#### SIFT (Scale-Invariant Feature Transform) Algorithm
|
||||
|
||||
1. A patented technology with nonfree functionality that uses image identifiers in order to identify a similar image, even those clicked from different angles, sizes, depths and scale, that they are included in the search results. Check the detailed video on SIFT here.
|
||||
2. SIFT correctly matches the search criteria with a large database of features from many images.
|
||||
3. Matching same images with different viewpoints and matching invariant features to obtain search results is another SIFT feature. Read more about scale-invariant keypoints here.
|
||||
|
||||
#### SURF (Speeded Up Robust Features) Algorithm
|
||||
|
||||
1. [SURF][1] is also patented with nonfree functionality and a more ‘speeded’ up version of SIFT. Unlike SIFT, SURF approximates Laplacian of Gaussian (unlike SIFT) with Box Filter.
|
||||
|
||||
2. SURF relies on the determinant of Hessian Matrix for both its location and scale.
|
||||
|
||||
3. Rotation invariance is not a requisite in many applications. So not finding this orientation speeds up the process.
|
||||
|
||||
4. SURF includes several features that the speed improved in each step. Three times faster than SIFT, SURF is great with rotation and blurring. It is not as great in illumination and viewpoint change though.
|
||||
|
||||
5. Open CV, a programming function library provides SURF functionalities. SURF.compute() and SURF. Detect() can be used to find descriptors and keypoints. Read more about SURF [here][2].
|
||||
|
||||
### Open Source Algorithms
|
||||
|
||||
#### KAZE Algorithm
|
||||
|
||||
1.KAZE is a open source 2D multiscale and novel feature detection and description algorithm in nonlinear scale spaces. Efficient techniques in Additive Operator Splitting (AOS) and variable conductance diffusion is used to build the nonlinear scale space.
|
||||
|
||||
2. Multiscale image processing basics are simple – Creating an image’s scale space while filtering original image with right function over enhancing time or scale.
|
||||
|
||||
#### AKAZE (Accelerated-KAZE) Algorithm
|
||||
|
||||
1. As the name suggests, this is a faster mode to image search, finding matching keypoints between two images. AKAZE uses a binary descriptor and nonlinear scale space that balances accuracy and speed.
|
||||
|
||||
#### BRISK (Binary Robust Invariant Scalable Keypoints) Algorithm
|
||||
|
||||
1. BRISK is great for description, keypoint detection and matching.
|
||||
|
||||
2. An algorithm that is highly adaptive, scale-space FAST-based detector along with a bit-string descriptor, helps speed up the search significantly.
|
||||
|
||||
3. Scale-space keypoint detection and keypoint description helps optimize the performance with relation to the task at hand.
|
||||
|
||||
#### FREAK (Fast Retina Keypoint)
|
||||
|
||||
1. This is a novel keypoint descriptor inspired by the human eye.A binary strings cascade is efficiently computed by an image intensity comparison. The FREAK algorithm allows faster computing with lower memory load as compared to BRISK, SURF and SIFT.
|
||||
|
||||
#### ORB (Oriented FAST and Rotated BRIEF)
|
||||
|
||||
1.A fast binary descriptor, ORB is resistant to noise and rotation invariant. ORB builds on the FAST keypoint detector and the BRIEF descriptor, elements attributed to its low cost and good performance.
|
||||
|
||||
2. Apart from the fast and precise orientation component, efficiently computing the oriented BRIEF, analyzing variance and co-relation of oriented BRIEF features, is another ORB feature.
|
||||
|
||||
### Python Libraries
|
||||
|
||||
#### Open CV
|
||||
|
||||
1. OpenCV is available for both academic and commercial use. A open source machine learning and computer vision library, OpenCV makes it easy for organizations to utilize and modify code.
|
||||
|
||||
2. Over 2500 optimized algorithms, including state-of-the-art machine learning and computer vision algorithms serve various image search purposes – face detection, object identification, camera movement tracking, finding similar images from image database, following eye movements, scenery recognition, etc.
|
||||
|
||||
3. Top companies like Google, IBM, Yahoo, IBM, Sony, Honda, Microsoft and Intel make wide use of OpenCV.
|
||||
|
||||
4. OpenCV uses Python, Java, C, C++ and MATLAB interfaces while supporting Windows, Linux, Mac OS and Android.
|
||||
|
||||
#### Python Imaging Library (PIL)
|
||||
|
||||
1. The Python Imaging Library (PIL) supports several file formats while providing image processing and graphics solutions.The open source PIL adds image processing capabilities to your Python interpreter.
|
||||
2. The standard procedure for image manipulation include image enhancing, transparency and masking handling, image filtering, per-pixel manipulation, etc.
|
||||
|
||||
For detailed statistics and graphs, view the OpenCV 2.4.9 Features Comparison Report [here][3].
|
||||
|
||||
### Building an Image Search Engine
|
||||
|
||||
An image search engine helps pick similar images from a prepopulated set of image base. The most popular among these is Google’s well known image search engine. For starters, there are various approaches to build a system like this. To mention a few:
|
||||
|
||||
1.Using image extraction, image description extraction, meta data extraction and search result extraction to build an image search engine.
|
||||
2. Define your image descriptor, dataset indexing, define your similarity metric and then search and rank.
|
||||
3. Select image to be searched, select directory for carrying out search, search directory for all pictures, create picture feature index, evaluate same feature for search picture, match pictures in search and obtain matched pictures.
|
||||
|
||||
Our approach basically began with comparing grayscaled versions of the images, gradually moving on to complex feature matching algorithms like SIFT and SURF, and then finally settling down to am open source solution called BRISK. All these algorithms give efficient results with minor changes in performance and latency. An engine built on these algorithms have numerous applications like analyzing graphic data for popularity statistics, identification of objects in graphic contents, and many more.
|
||||
|
||||
**Example**: An image search engine needs to be build by an IT company for a client. So if a brand logo image is submitted in the search, all related brand image searches show up as results. The obtained results can also be used for analytics by the client, allowing them to estimate the brand popularity as per the geographic location. Its still early days though, RIQ or reverse image search has not been exploited to its full extent yet.
|
||||
|
||||
This concludes our article on building an image search engine using Python. Check our blog section out for the latest on technology and programming.
|
||||
|
||||
Statistics Source: OpenCV 2.4.9 Features Comparison Report (computer-vision-talks.com)
|
||||
|
||||
(Guidance and additional inputs by Ananthu Nair.)
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.cuelogic.com/blog/advanced-image-processing-with-python/
|
||||
|
||||
作者：[Snehith Kumbla][a]
|
||||
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]: http://www.cuelogic.com/blog/author/snehith-kumbla/
|
||||
[1]: http://docs.opencv.org/3.0-beta/doc/py_tutorials/py_feature2d/py_surf_intro/py_surf_intro.html
|
||||
[2]: http://www.vision.ee.ethz.ch/~surf/eccv06.pdf
|
||||
[3]: https://docs.google.com/spreadsheets/d/1gYJsy2ROtqvIVvOKretfxQG_0OsaiFvb7uFRDu5P8hw/edit#gid=10
|
||||
@ -0,0 +1,150 @@
|
||||
name1e5s translating
|
||||
|
||||
TOP 5 BEST VIDEO EDITING SOFTWARE FOR LINUX IN 2016
|
||||
=====================================================
|
||||
|
||||
|
||||
|
||||
Brief: Tiwo discusses the best video editors for Linux, their pros and cons and the installation method for Ubuntu-based distros in this article.
|
||||
|
||||
We have discussed [best photo management applications for Linux][1], [best code editors for Linux][2] in similar articles in the past. Today we shall see the best video editing software for Linux.
|
||||
|
||||
When asked about free video editing software, Windows Movie Maker and iMovie is what most people often suggest.
|
||||
|
||||
Unfortunately, both of them are not available for GNU/Linux. But you don’t need to worry about it, we have pooled together a list of best free video editors for you.
|
||||
|
||||
### BEST VIDEO EDITOR APPS FOR LINUX
|
||||
|
||||
Let’s have a look at the top 5 best free video editing software for Linux below :
|
||||
|
||||
#### 1. KDENLIVE
|
||||
|
||||
|
||||
|
||||
[Kdenlive][3] is a free and [open source][4] video editing software from KDE that provides dual video monitors, a multi-track timeline, clip list, customizable layout support, basic effects, and basic transitions.
|
||||
It supports wide variety of file formats and a wide range of camcorders and cameras including Low resolution camcorder (Raw and AVI DV editing), Mpeg2, mpeg4 and h264 AVCHD (small cameras and camcorders), High resolution camcorder files, including HDV and AVCHD camcorders, Professional camcorders, including XDCAM-HD™ streams, IMX™ (D10) streams, DVCAM (D10) , DVCAM, DVCPRO™, DVCPRO50™ streams and DNxHD™ streams.
|
||||
|
||||
You can install it from terminal by running the following command :
|
||||
|
||||
```
|
||||
sudo apt-get install kdenlive
|
||||
```
|
||||
|
||||
Or, open Ubuntu Software Center then search Kdenlive.
|
||||
|
||||
#### 2. OPENSHOT
|
||||
|
||||
|
||||
|
||||
[OpenShot][5] is the second choice in our list of Linux video editing software. OpenShot can help you create the film that supports for transitions, effects, adjusting audio levels, and of course, it support of most formats and codecs.
|
||||
|
||||
You can also export your film to DVD, upload to YouTube, Vimeo, Xbox 360, and many other common formats. OpenShot is simpler than kdenlive. So if you need a video editor with a simple UI OpenShot is a good choice.
|
||||
|
||||
The latest version is 2.0.7. You can install OpenShot video editor by run the following command from terminal window :
|
||||
|
||||
```
|
||||
sudo apt-get install openshot
|
||||
```
|
||||
|
||||
It needs to download 25 MB, and 70 MB disk space after installed.
|
||||
|
||||
#### 3. FLOWBLADE MOVIE EDITOR
|
||||
|
||||
|
||||
|
||||
[Flowblade Movie Editor][6] is a multitrack non-linear video editor for Linux. It is free and open source. It comes with a stylish and modern user interface.
|
||||
|
||||
Written in Python, it is designed to provide a fast, and precise. Flowblade has focused on providing the best possible experience on Linux and other free platforms. So there’s no Windows and OS X version for now.
|
||||
|
||||
To install Flowblade in Ubuntu and other Ubuntu based systems, use the command below:
|
||||
|
||||
```
|
||||
sudo apt-get install flowblade
|
||||
```
|
||||
|
||||
#### 4. LIGHTWORKS
|
||||
|
||||
|
||||
|
||||
If you looking for a video editor software that has more feature, this is the answer. [Lightworks][7] is a cross-platform professional video editor, available for Linux, Mac OS X and Windows.
|
||||
|
||||
It is an award winning professional [non-linear editing][8] (NLE) software that supports resolutions up to 4K as well as video in SD and HD formats.
|
||||
|
||||
This application has two versions: Lightworks Free and Lightworks Pro. While free version doesn’t support Vimeo (H.264 / MPEG-4) and YouTube (H.264 / MPEG-4)- Up to 2160p (4K UHD), Blu-ray, and H.264/MP4 export option with configurable bitrate setting, then pro version is.
|
||||
|
||||
- Lightworks Free
|
||||
- Lightworks Pro
|
||||
|
||||
Pro version has more features such as higher resolution support, 4K and Blue Ray support etc.
|
||||
|
||||
##### HOW TO INSTALL LIGHTWORKS?
|
||||
|
||||
Unlike the other video editors, installing Lightwork is not as straight forward as running a single command. Don’t worry, it’s not that complicated either.
|
||||
|
||||
- Step 1 – You can get the package from [Lightworks Downloads Page][9]. The package’s size about 79,5 MB.
|
||||
|
||||
>Please note: There’s no Linux 32-bit support.
|
||||
|
||||
- Step 2 – Once downloaded, you can install it using [Gdebi package installer][10]. Gdebi automatically downloads the dependency :
|
||||
|
||||
|
||||
|
||||
- Step 3 – Now you can open it from Ubuntu dashboard, or your Linux distro’s menu.
|
||||
|
||||
- Step 4 – It needs an account when you use it for first time. Click at Not Registerd? button to register. Don’t worry, it’s free!
|
||||
|
||||
- Step 5 – After your account has been verified, now login.
|
||||
|
||||
Now the Lightworks is ready to use.
|
||||
|
||||
Need Lightworks video tutorial? Get them at [Lightworks video tutorials Page][11].
|
||||
|
||||
#### 5. BLENDER
|
||||
|
||||
|
||||
|
||||
Blender is a professional, industry-grade open source, cross platform video editor. It is popular for 3D works. Blender has been used in several Hollywood movies including Spider Man series.
|
||||
|
||||
Although originally designed for produce 3D modeling, but it can also be used for video editing and input capabilities with a variety of formats. The Video Editor includes:
|
||||
|
||||
- Live preview, luma waveform, chroma vectorscope and histogram displays
|
||||
- Audio mixing, syncing, scrubbing and waveform visualization
|
||||
- Up to 32 slots for adding video, images, audio, scenes, masks and effects
|
||||
- Speed control, adjustment layers, transitions, keyframes, filters and more.
|
||||
|
||||
The latest version can be downloaded from [Blender Download Page][12].
|
||||
|
||||
### WHICH IS THE BEST VIDEO EDITING SOFTWARE?
|
||||
|
||||
If you need a simple video editor, OpenShot, Kdenlive or Flowblade is a good choice. These are suitable for beginners and a system with standard specification.
|
||||
|
||||
Then if you have a high-end computer, and need advanced features you can go out with Lightworks. If you are looking for more advanced features, Blender has got your back.
|
||||
|
||||
So that’s all I can write about 5 best video editing software for Linux such as Ubuntu, Linux Mint, Elementary, and other Linux distributions. Share with us which video editor you like the most.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/best-video-editing-software-linux/
|
||||
|
||||
作者：[Tiwo Satriatama][a]
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/tiwo/
|
||||
[1]: https://itsfoss.com/linux-photo-management-software/
|
||||
[2]: https://itsfoss.com/best-modern-open-source-code-editors-for-linux/
|
||||
[3]: https://kdenlive.org/
|
||||
[4]: https://itsfoss.com/tag/open-source/
|
||||
[5]: http://www.openshot.org/
|
||||
[6]: http://jliljebl.github.io/flowblade/
|
||||
[7]: https://www.lwks.com/
|
||||
[8]: https://en.wikipedia.org/wiki/Non-linear_editing_system
|
||||
[9]: https://www.lwks.com/index.php?option=com_lwks&view=download&Itemid=206
|
||||
[10]: https://itsfoss.com/gdebi-default-ubuntu-software-center/
|
||||
[11]: https://www.lwks.com/videotutorials
|
||||
[12]: https://www.blender.org/download/
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,305 @@
|
||||
translating by fw8899
|
||||
18 Best IDEs for C/C++ Programming or Source Code Editors on Linux
|
||||
======================================================================
|
||||
|
||||
C++, an extension of well known C language, is an excellent, powerful and general purpose programming language that offers modern and generic programming features for developing large-scale applications ranging from video games, search engines, other computer software to operating systems.
|
||||
|
||||
C++ is highly reliable and also enables low-level memory manipulation for more advanced programming requirements.
|
||||
|
||||
|
||||
|
||||
There are several text editors out there that programmers can use to write C/C++ code, but IDE have come up to offer comprehensive facilities and components for easy and ideal programming.
|
||||
|
||||
In this article, we shall look at some of the best IDE’s you can find on the Linux platform for C++ or any other programming.
|
||||
|
||||
### 1. Netbeans for C/C++ Development
|
||||
|
||||
Netbeans is a free, open-source and popular cross-platform IDE for C/C++ and many other programming languages. Its fully extensible using community developed plugins.
|
||||
|
||||
It includes project types and templates for C/C++ and you can build applications using static and dynamic libraries. Additionally, you can reuse existing code to create your projects, and also use drag and drop feature to import binary files into it to build applications from the ground.
|
||||
|
||||
Let us look at some of its features:
|
||||
|
||||
- The C/C++ editor is well integrated with multi-session [GNU GDB][1] debugger tool.
|
||||
- Support for code assistance
|
||||
- C++11 support
|
||||
- Create and run C/C++ tests from within
|
||||
- Qt toolkit support
|
||||
- Support for automatic packaging of compiled application into .tar, .zip and many more archive files
|
||||
- Support for multiple compilers such as GNU, Clang/LLVM, Cygwin, Oracle Solaris Studio and MinGW
|
||||
- Support for remote development
|
||||
- File navigation
|
||||
- Source inspection
|
||||
|
||||
|
||||
>Visit Homepage: <https://netbeans.org/features/cpp/index.html>
|
||||
|
||||
### 2. Code::Blocks
|
||||
|
||||
Code::Blocks is a free, highly extensible and configurable, cross-platform C++ IDE built to offer users the most demanded and ideal features. It delivers a consistent user interface and feel.
|
||||
|
||||
And most importantly, you can extend its functionality by using plugins developed by users, some of the plugins are part of Code::Blocks release and many are not, written by individual users not part of the Code::Block development team.
|
||||
|
||||
Its features are categorized into compiler, debugger and interface features and these include:
|
||||
|
||||
Multiple compiler support including GCC, clang, Borland C++ 5.5, digital mars plus many more
|
||||
Very fast, no need for makefiles
|
||||
Multi-target projects
|
||||
Workspace that supports combining of projects
|
||||
Interfaces GNU GDB
|
||||
Support for full breakpoints including code breakpoints, data breakpoints, breakpoint conditions plus many more
|
||||
display local functions symbols and arguments
|
||||
custom memory dump and syntax highlighting
|
||||
Customizable and extensible interface plus many more other features including those added through user built plugins
|
||||
|
||||
|
||||
>Visit Homepage: <http://www.codeblocks.org>
|
||||
|
||||
### 3. Eclipse CDT(C/C++ Development Tooling)
|
||||
|
||||
Eclipse is a well known open-source, cross-platform IDE in the programming arena. It offers users a great GUI with support for drag and drop functionality for easy arrangement of interface elements.
|
||||
|
||||
The Eclipse CDT is a project based on the primary Eclipse platform and it provides a full functional C/C++ IDE with following features:
|
||||
|
||||
- Supports project creation
|
||||
- Managed build for various toolchains
|
||||
- Standard make build
|
||||
- Source navigation
|
||||
- Several knowledge tools such as call graph, type hierarchy, in-built browser, macro definition browser
|
||||
- Code editor with support for syntax highlighting
|
||||
- Support for folding and hyperlink navigation
|
||||
- Source code refactoring plus code generation
|
||||
- Tools for visual debugging such as memory, registers
|
||||
- Disassembly viewers and many more
|
||||
|
||||
|
||||
>Visit Homepage: <http://www.eclipse.org/cdt/>
|
||||
|
||||
### 4. CodeLite IDE
|
||||
|
||||
CodeLite is also a free, open-source, cross-platform IDE designed and built specifically for C/C++, JavaScript (Node.js) and PHP programming.
|
||||
|
||||
Some of its main features include:
|
||||
|
||||
- Code completion, and it offers two code completion engines
|
||||
- Supports several compilers including GCC, clang/VC++
|
||||
- Displays errors as code glossary
|
||||
- Clickable errors via build tab
|
||||
- Support for LLDB next generation debugger
|
||||
- GDB support
|
||||
- Support for refactoring
|
||||
- Code navigation
|
||||
- Remote development using built-in SFTP
|
||||
- Source control plugins
|
||||
- RAD (Rapid Application Development) tool for developing wxWidgets-based apps plus many more features
|
||||
|
||||
|
||||
>Visit Homepage: <http://codelite.org/>
|
||||
|
||||
### 6. Bluefish Editor
|
||||
|
||||
Bluefish is a more than just a normal editor, it is a lightweight, fast editor that offers programmers IDE like features for developing websites, writing scripts and software code. It is multi-platform, runs on Linux, Mac OSX, FreeBSD, OpenBSD, Solaris and Windows, and also supports many programming languages including C/C++.
|
||||
|
||||
It is feature rich including the ones listed below:
|
||||
|
||||
- Multiple document interface
|
||||
- Supports recursive opening of files based on filename patterns or content pattern
|
||||
- Offers a very powerful search and replace functionality
|
||||
- Snippet sidebar
|
||||
- Support for integrating external filters of your own, pipe documents using commands such as awk, sed, sort plus custom built scripts
|
||||
- Supports full screen editing
|
||||
- Site uploader and downloader
|
||||
- Multiple encoding support and many more other features
|
||||
|
||||
|
||||
>Visit Homepage: <http://bluefish.openoffice.nl>
|
||||
|
||||
### 7. Brackets Code Editor
|
||||
|
||||
Brackets is a modern and open-source text editor designed specifically for web designing and development. It is highly extensible through plugins, therefore C/C++ programmers can use it by installing the C/C++/Objective-C pack extension, this pack is designed to enhance C/C++ code writing and to offer IDE like features.
|
||||
|
||||
|
||||
>Visit Homepage: <http://brackets.io/>
|
||||
|
||||
### 8. Atom Code Editor
|
||||
|
||||
Atom is also a modern, open-source, multi-platform text editor that can run on Linux, Windows or Mac OS X. It is also hackable down to its base, therefore users can customize it to meet their code writing demands.
|
||||
|
||||
It is fully featured and some of its main features include:
|
||||
|
||||
- Built-in package manager
|
||||
- Smart auto-completion
|
||||
- In-built file browser
|
||||
- Find and replace functionality and many more
|
||||
|
||||
|
||||
>Visit Homepage: >https://atom.io/>
|
||||
>Installation Instructions: <http://www.tecmint.com/atom-text-and-source-code-editor-for-linux/>
|
||||
|
||||
### 9. Sublime Text Editor
|
||||
|
||||
Sublime Text is a well refined, multi-platform text editor designed and developed for code, markup and prose. You can use it for writing C/C++ code and offers a great user interface.
|
||||
|
||||
It’s features list comprises of:
|
||||
|
||||
- Multiple selections
|
||||
- Command palette
|
||||
- Goto anything functionality
|
||||
- Distraction free mode
|
||||
- Split editing
|
||||
- Instant project switching support
|
||||
- Highly customizable
|
||||
- Plugin API support based on Python plus other small features
|
||||
|
||||
|
||||
>Visit Homepage: <https://www.sublimetext.com>
|
||||
>Installation Instructions: <http://www.tecmint.com/install-sublime-text-editor-in-linux/>
|
||||
|
||||
### 10. JetBrains CLion
|
||||
|
||||
CLion is a non-free, powerful and cross-platform IDE for C/C++ programming. It is a fully integrated C/C++ development environment for programmers, providing Cmake as a project model, an embedded terminal window and a keyboard oriented approach to code writing.
|
||||
|
||||
It also offers a smart and modern code editor plus many more exciting features to enable an ideal code writing environment and these features include:
|
||||
|
||||
- Supports several languages other than C/C++
|
||||
- Easy navigation to symbol declarations or context usage
|
||||
- Code generation and refactoring
|
||||
- Editor customization
|
||||
- On-the-fly code analysis
|
||||
- An integrated code debugger
|
||||
- Supports Git, Subversion, Mercurial, CVS, Perforce(via plugin) and TFS
|
||||
- Seamlessly integrates with Google test frameworks
|
||||
- Support for Vim text editor via Vim-emulation plugin
|
||||
|
||||
|
||||
>Visit Homepage: <https://www.jetbrains.com/clion/>
|
||||
|
||||
### 11. Microsoft’s Visual Studio Code Editor
|
||||
|
||||
Visual Studio is a rich, fully integrated, cross-platform development environment that runs on Linux, Windows and Mac OS X. It was recently made open-source to Linux users and it has redefined code editing, offering users every tool needed for building every app for multiple platforms including Windows, Android, iOS and the web.
|
||||
|
||||
It is feature full, with features categorized under application development, application lifecycle management, and extend and integrate features. You can read a comprehensive features list from the Visual Studio website.
|
||||
|
||||
|
||||
>Visit Homepage: <https://www.visualstudio.com>
|
||||
|
||||
### 12. KDevelop
|
||||
|
||||
KDevelop is just another free, open-source and cross-platform IDE that works on Linux, Solaris, FreeBSD, Windows, Mac OSX and other Unix-like operating systems. It is based on the KDevPlatform, KDE and Qt libraries. KDevelop is highly extensible through plugins and feature rich with the following notable features:
|
||||
|
||||
- Support for Clang-based C/C++ plugin
|
||||
- KDE 4 config migration support
|
||||
- Revival of Oketa plugin support
|
||||
- Support for different line editings in various views and plugins
|
||||
- Support for Grep view and Uses widget to save vertical space plus many more
|
||||
|
||||
|
||||
>Visit Homepage: <https://www.kdevelop.org>
|
||||
|
||||
### 13. Geany IDE
|
||||
|
||||
Geany is a free, fast, lightweight and cross-platform IDE developed to work with few dependencies and also operate independently from popular Linux desktops such as GNOME and KDE. It requires GTK2 libraries for functionality.
|
||||
|
||||
Its features list consists of the following:
|
||||
|
||||
- Support for syntax highlighting
|
||||
- Code folding
|
||||
- Call tips
|
||||
- Symbol name auto completion
|
||||
- Symbol lists
|
||||
- Code navigation
|
||||
- A simple project management tool
|
||||
- In-built system to compile and run a users code
|
||||
- Extensible through plugins
|
||||
|
||||
|
||||
>Visit Homepage: <http://www.geany.org/>
|
||||
|
||||
### 14. Ajunta DeveStudio
|
||||
|
||||
Ajunta DevStudio is a simple GNOME yet powerful software development studio that supports several programming languages including C/C++.
|
||||
|
||||
It offers advanced programming tools such as project management, GUI designer, interactive debugger, application wizard, source editor, version control plus so many other facilities. Additionally, to above features, Ajunta DevStudio also has some other great IDE features and these include:
|
||||
|
||||
- Simple user interface
|
||||
- Extensible with plugins
|
||||
- Integrated Glade for WYSIWYG UI development
|
||||
- Project wizards and templates
|
||||
- Integrated GDB debugger
|
||||
- In-built file manager
|
||||
- Integrated DevHelp for context sensitive programming help
|
||||
- Source code editor with features such as syntax highlighting, smart indentation, auto-indentation, code folding/hiding, text zooming plus many more
|
||||
|
||||
|
||||
>Visit Homepage: <http://anjuta.org/>
|
||||
|
||||
### 15. The GNAT Programming Studio
|
||||
|
||||
The GNAT Programming Studio is a free easy to use IDE designed and developed to unify the interaction between a developer and his/her code and software.
|
||||
|
||||
Built for ideal programming by facilitating source navigation while highlighting important sections and ideas of a program. It is also designed to offer a high-level of programming comfortability, enabling users to developed comprehensive systems from the ground.
|
||||
|
||||
It is feature rich with the following features:
|
||||
|
||||
- - Intuitive user interface
|
||||
- Developer friendly
|
||||
- Multi-lingual and multi-platform
|
||||
- Flexible MDI(multiple document interface)
|
||||
- Highly customizable
|
||||
- Fully extensible with preferred tools
|
||||
|
||||
|
||||
>Visit Homepage: <http://libre.adacore.com/tools/gps/>
|
||||
|
||||
### 16. Qt Creator
|
||||
|
||||
It is a non-free, cross-platform IDE designed for creation of connected devices, UIs and applications. Qt creator enables users to do more of creation than actual coding of applications.
|
||||
|
||||
It can be used to create mobile and desktop applications, and also connected embedded devices.
|
||||
|
||||
Some of its features include:
|
||||
|
||||
- Sophisticated code editor
|
||||
- Support for version control
|
||||
- Project and build management tools
|
||||
- Multi-screen and multi-platform support for easy switching between build targets plus many more
|
||||
|
||||
|
||||
>Visit Homepage: <https://www.qt.io/ide/>
|
||||
|
||||
### 17. Emacs Editor
|
||||
|
||||
Emacs is a free, powerful, highly extensible and customizable, cross-platform text editors you can use on Linux, Solaris, FreeBSD, NetBSD, OpenBSD, Windows and Mac OS X.
|
||||
|
||||
The core of Emacs is also an interpreter for Emacs Lisp which is a language under the Lisp programming language. As of this writing, the latest release of GNU Emacs is version 24.5 and the fundamental and notable features of Emacs include:
|
||||
|
||||
- Content-aware editing modes
|
||||
- Full Unicode support
|
||||
- Highly customizable using GUI or Emacs Lisp code
|
||||
- A packaging system for downloading and installing extensions
|
||||
- Ecosystem of functionalities beyond normal text editing including project planner, mail, calender and news reader plus many more
|
||||
- A complete built-in documentation plus user tutorials and many more
|
||||
|
||||
|
||||
>Visit Homepage: https://www.gnu.org/software/emacs/
|
||||
|
||||
### 18. VI/VIM Editor
|
||||
|
||||
Vim an improved version of VI editor, is a free, powerful, popular and highly configurable text editor. It is built to enable efficient text editing, and offers exciting editor features for Unix/Linux users, therefore, it is also a good option for writing and editing C/C++ code.
|
||||
|
||||
Generally, IDEs offer more programming comfortability then traditional text editors, therefore it is always a good idea to use them. They come with exciting features and offer a comprehensive development environment, sometimes programmers are caught up between choosing the best IDE to use for C/C++ programming.
|
||||
|
||||
There many other IDEs you can find out there and download from the Internet, but trying out several of them can help you find that which suites your needs.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/best-linux-ide-editors-source-code-editors/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
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]: http://www.tecmint.com/author/aaronkili/
|
||||
[1]: http://www.tecmint.com/debug-source-code-in-linux-using-gdb/
|
||||
@ -1,33 +0,0 @@
|
||||
What makes up the Fedora kernel?
|
||||
====================================
|
||||
|
||||
|
||||
|
||||
Every Fedora system runs a kernel. Many pieces of code come together to make this a reality.
|
||||
|
||||
Each release of the Fedora kernel starts with a baseline release from the [upstream community][1]. This is often called a ‘vanilla’ kernel. The upstream kernel is the standard. The goal is to have as much code upstream as possible. This makes it easier for bug fixes and API updates to happen as well as having more people review the code. In an ideal world, Fedora would be able to to take the kernel straight from kernel.org and send that out to all users.
|
||||
|
||||
Realistically, using the vanilla kernel isn’t complete enough for Fedora. Some features Fedora users want may not be available. The [Fedora kernel][2] that users actually receive contains a number of patches on top of the vanilla kernel. These patches are considered ‘out of tree’. Many of these patches will not exist out of tree patches very long. If patches are available to fix an issue, the patches may be pulled in to the Fedora tree so the fix can go out to users faster. When the kernel is rebased to a new version, the patches will be removed if they are in the new version.
|
||||
|
||||
Some patches remain in the Fedora kernel tree for an extended period of time. A good example of patches that fall into this category are the secure boot patches. These patches provide a feature Fedora wants to support even though the upstream community has not yet accepted them. It takes effort to keep these patches up to date so Fedora tries to minimize the number of patches that are carried without being accepted by an upstream kernel maintainer.
|
||||
|
||||
Generally, the best way to get a patch included in the Fedora kernel is to send it to the ]Linux Kernel Mailing List (LKML)][3] first and then ask for it to be included in Fedora. If a patch has been accepted by a maintainer it stands a very high chance of being included in the Fedora kernel tree. Patches that come from places like github which have not been submitted to LKML are unlikely to be taken into the tree. It’s important to send the patches to LKML first to ensure Fedora is carrying the correct patches in its tree. Without the community review, Fedora could end up carrying patches which are buggy and cause problems.
|
||||
|
||||
The Fedora kernel contains code from many places. All of it is necessary to give the best experience possible.
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/makes-fedora-kernel/
|
||||
|
||||
作者：[Laura Abbott][a]
|
||||
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/makes-fedora-kernel/
|
||||
[1]: http://www.kernel.org/
|
||||
[2]: http://pkgs.fedoraproject.org/cgit/rpms/kernel.git/
|
||||
[3]: http://www.labbott.name/blog/2015/10/02/the-art-of-communicating-with-lkml/
|
||||
@ -1,143 +0,0 @@
|
||||
How To Setup Bridge (br0) Network on Ubuntu Linux 14.04 and 16.04 LTS
|
||||
=======================================================================
|
||||
|
||||
> am a new Ubuntu Linux 16.04 LTS user. How do I setup a network bridge on the host server powered by Ubuntu 14.04 LTS or 16.04 LTS operating system?
|
||||
|
||||
|
||||
|
||||
A Bridged networking is nothing but a simple technique to connect to the outside network through the physical interface. It is useful for LXC/KVM/Xen/Containers virtualization and other virtual interfaces. The virtual interfaces appear as regular hosts to the rest of the network. In this tutorial I will explain how to configure a Linux bridge with bridge-utils (brctl) command line utility on Ubuntu server.
|
||||
|
||||
### Our sample bridged networking
|
||||
|
||||
|
||||
>Fig.01: Sample Ubuntu Bridged Networking Setup For Kvm/Xen/LXC Containers (br0)
|
||||
|
||||
In this example eth0 and eth1 is the physical network interface. eth0 connected to the LAN and eth1 is attached to the upstream ISP router/Internet.
|
||||
|
||||
### Install bridge-utils
|
||||
|
||||
Type the following [apt-get command][1] to install the bridge-utils:
|
||||
|
||||
```
|
||||
$ sudo apt-get install bridge-utils
|
||||
```
|
||||
|
||||
OR
|
||||
|
||||
````
|
||||
$ sudo apt install bridge-utils
|
||||
```
|
||||
|
||||
Sample outputs:
|
||||
|
||||
|
||||
>Fig.02: Ubuntu Linux install bridge-utils package
|
||||
|
||||
### Creating a network bridge on the Ubuntu server
|
||||
|
||||
Edit `/etc/network/interfaces` using a text editor such as nano or vi, enter:
|
||||
|
||||
```
|
||||
$ sudo cp /etc/network/interfaces /etc/network/interfaces.bakup-1-july-2016
|
||||
$ sudo vi /etc/network/interfaces
|
||||
```
|
||||
|
||||
Let us setup eth1 and map it to br1, enter (delete or comment out all eth1 entries):
|
||||
|
||||
```
|
||||
# br1 setup with static wan IPv4 with ISP router as gateway
|
||||
auto br1
|
||||
iface br1 inet static
|
||||
address 208.43.222.51
|
||||
network 255.255.255.248
|
||||
netmask 255.255.255.0
|
||||
broadcast 208.43.222.55
|
||||
gateway 208.43.222.49
|
||||
bridge_ports eth1
|
||||
bridge_stp off
|
||||
bridge_fd 0
|
||||
bridge_maxwait 0
|
||||
```
|
||||
|
||||
To setup eth0 and map it to br0, enter (delete or comment out all eth1 entries):
|
||||
|
||||
```
|
||||
auto br0
|
||||
iface br0 inet static
|
||||
address 10.18.44.26
|
||||
netmask 255.255.255.192
|
||||
broadcast 10.18.44.63
|
||||
dns-nameservers 10.0.80.11 10.0.80.12
|
||||
# set static route for LAN
|
||||
post-up route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.18.44.1
|
||||
post-up route add -net 161.26.0.0 netmask 255.255.0.0 gw 10.18.44.1
|
||||
bridge_ports eth0
|
||||
bridge_stp off
|
||||
bridge_fd 0
|
||||
bridge_maxwait 0
|
||||
```
|
||||
|
||||
### A note about br0 and DHCP
|
||||
|
||||
DHCP config options:
|
||||
|
||||
```
|
||||
auto br0
|
||||
iface br0 inet dhcp
|
||||
bridge_ports eth0
|
||||
bridge_stp off
|
||||
bridge_fd 0
|
||||
bridge_maxwait 0
|
||||
```
|
||||
|
||||
Save and close the file.
|
||||
|
||||
### Restart the server or networking service
|
||||
|
||||
You need to reboot the server or type the following command to restart the networking service (this may not work on SSH based session):
|
||||
|
||||
```
|
||||
$ sudo systemctl restart networking
|
||||
```
|
||||
|
||||
If you are using Ubuntu 14.04 LTS or older not systemd based system, enter:
|
||||
|
||||
```
|
||||
$ sudo /etc/init.d/restart networking
|
||||
```
|
||||
|
||||
### Verify connectivity
|
||||
|
||||
Use the ping/ip commands to verify that both LAN and WAN interfaces are reachable:
|
||||
```
|
||||
# See br0 and br1
|
||||
ip a show
|
||||
# See routing info
|
||||
ip r
|
||||
# ping public site
|
||||
ping -c 2 cyberciti.biz
|
||||
# ping lan server
|
||||
ping -c 2 10.0.80.12
|
||||
```
|
||||
|
||||
Sample outputs:
|
||||
|
||||
|
||||
>Fig.03: Verify Bridging Ethernet Connections
|
||||
|
||||
Now, you can configure XEN/KVM/LXC containers to use br0 and br1 to reach directly to the internet or private lan. No need to setup special routing or iptables SNAT rules.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.cyberciti.biz/faq/how-to-create-bridge-interface-ubuntu-linux/
|
||||
|
||||
作者：[VIVEK GITE][a]
|
||||
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://twitter.com/nixcraft
|
||||
[1]: http://www.cyberciti.biz/tips/linux-debian-package-management-cheat-sheet.html
|
||||
|
||||
@ -1,100 +0,0 @@
|
||||
How to Encrypt a Flash Drive Using VeraCrypt
|
||||
============================================
|
||||
|
||||
Many security experts prefer open source software like VeraCrypt, which can be used to encrypt flash drives, because of its readily available source code.
|
||||
|
||||
Encryption is a smart idea for protecting data on a USB flash drive, as we covered in our piece that described ]how to encrypt a flash drive][1] using Microsoft BitLocker.
|
||||
|
||||
But what if you do not want to use BitLocker?
|
||||
|
||||
You may be concerned that because Microsoft's source code is not available for inspection, it could be susceptible to security "backdoors" used by the government or others. Because source code for open source software is widely shared, many security experts feel open source software is far less likely to have any backdoors.
|
||||
|
||||
Fortunately, there are several open source encryption alternatives to BitLocker.
|
||||
|
||||
If you need to be able to encrypt and access files on any Windows machine, as well as computers running Apple OS X or Linux, the open source [VeraCrypt][2] offers an excellent alternative.
|
||||
|
||||
VeraCrypt is derived from TrueCrypt, a well-regarded open source encryption software product that has now been discontinued. But the code for TrueCrypt was audited and no major security flaws were found. In addition, it has since been improved in VeraCrypt.
|
||||
|
||||
Versions exist for Windows, OS X and Linux.
|
||||
|
||||
Encrypting a USB flash drive with VeraCrypt is not as straightforward as it is with BitLocker, but it still only takes a few minutes.
|
||||
|
||||
### Encrypting Flash Drive with VeraCrypt in 8 Steps
|
||||
|
||||
After [downloading VeraCrypt][3] for your operating system:
|
||||
|
||||
Start VeraCrypt, and click on Create Volume to start the VeraCrypt Volume Creation Wizard.
|
||||
|
||||
|
||||
|
||||
The VeraCrypt Volume Creation Wizard allows you to create an encrypted file container on the flash drive which sits along with other unencrypted files, or you can choose to encrypt the entire flash drive. For the moment, we will choose to encrypt the entire flash drive.
|
||||
|
||||
|
||||
|
||||
On the next screen, choose Standard VeraCrypt Volume.
|
||||
|
||||
|
||||
|
||||
Select the drive letter of the flash drive you want to encrypt (in this case O:).
|
||||
|
||||
|
||||
|
||||
Choose the Volume Creation Mode. If your flash drive is empty or you want to delete everything it contains, choose the first option. If you want to keep any existing files, choose the second option.
|
||||
|
||||
|
||||
|
||||
This screen allows you to choose your encryption options. If you are unsure of which to choose, leave the default settings of AES and SHA-512.
|
||||
|
||||
|
||||
|
||||
After confirming the Volume Size screen, enter and re-enter the password you want to use to encrypt your data.
|
||||
|
||||
|
||||
|
||||
To work effectively, VeraCrypt must draw from a pool of entropy or "randomness." To generate this pool, you'll be asked to move your mouse around in a random fashion for about a minute. Once the bar has turned green, or preferably when it reaches the far right of the screen, click Format to finish creating your encrypted drive.
|
||||
|
||||
|
||||
|
||||
### Using a Flash Drive Encrypted with VeraCrypt
|
||||
|
||||
When you want to use an encrypted flash drive, first insert the drive in the computer and start VeraCrypt.
|
||||
|
||||
Then select an unused drive letter (such as z:) and click Auto-Mount Devices.
|
||||
|
||||
|
||||
|
||||
Enter your password and click OK.
|
||||
|
||||
|
||||
|
||||
The mounting process may take a few minutes, after which your unencrypted drive will become available with the drive letter you selected previously.
|
||||
|
||||
### VeraCrypt Traveler Disk Setup
|
||||
|
||||
If you set up a flash drive with an encrypted container rather than encrypting the whole drive, you also have the option to create what VeraCrypt calls a traveler disk. This installs a copy of VeraCrypt on the USB flash drive itself, so when you insert the drive in another Windows computer you can run VeraCrypt automatically from the flash drive; there is no need to install it on the computer.
|
||||
|
||||
You can set up a flash drive to be a Traveler Disk by choosing Traveler Disk SetUp from the Tools menu of VeraCrypt.
|
||||
|
||||
|
||||
|
||||
It is worth noting that in order to run VeraCrypt from a Traveler Disk on a computer, you must have administrator privileges on that computer. While that may seem to be a limitation, no confidential files can be opened safely on a computer that you do not control, such as one in a business center.
|
||||
|
||||
>Paul Rubens has been covering enterprise technology for over 20 years. In that time he has written for leading UK and international publications including The Economist, The Times, Financial Times, the BBC, Computing and ServerWatch.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.esecurityplanet.com/open-source-security/how-to-encrypt-flash-drive-using-veracrypt.html
|
||||
|
||||
作者：[Paul Rubens ][a]
|
||||
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]: http://www.esecurityplanet.com/author/3700/Paul-Rubens
|
||||
[1]: http://www.esecurityplanet.com/views/article.php/3880616/How-to-Encrypt-a-USB-Flash-Drive.htm
|
||||
[2]: http://www.esecurityplanet.com/open-source-security/veracrypt-a-worthy-truecrypt-alternative.html
|
||||
[3]: https://veracrypt.codeplex.com/releases/view/619351
|
||||
|
||||
|
||||
|
||||
123
sources/tech/20160706 What is Git.md
Normal file
123
sources/tech/20160706 What is Git.md
Normal file
@ -0,0 +1,123 @@
|
||||
translating by cvsher
|
||||
What is Git
|
||||
===========
|
||||
|
||||
Welcome to my series on learning how to use the Git version control system! In this introduction to the series, you will learn what Git is for and who should use it.
|
||||
|
||||
If you're just starting out in the open source world, you're likely to come across a software project that keeps its code in, and possibly releases it for use, by way of Git. In fact, whether you know it or not, you're certainly using software right now that is developed using Git: the Linux kernel (which drives the website you're on right now, if not the desktop or mobile phone you're accessing it on), Firefox, Chrome, and many more projects share their codebase with the world in a Git repository.
|
||||
|
||||
On the other hand, all the excitement and hype over Git tends to make things a little muddy. Can you only use Git to share your code with others, or can you use Git in the privacy of your own home or business? Do you have to have a GitHub account to use Git? Why use Git at all? What are the benefits of Git? Is Git the only option?
|
||||
|
||||
So forget what you know or what you think you know about Git, and let's take it from the beginning.
|
||||
|
||||
### What is version control?
|
||||
|
||||
Git is, first and foremost, a version control system (VCS). There are many version control systems out there: CVS, SVN, Mercurial, Fossil, and, of course, Git.
|
||||
|
||||
Git serves as the foundation for many services, like GitHub and GitLab, but you can use Git without using any other service. This means that you can use Git privately or publicly.
|
||||
|
||||
If you have ever collaborated on anything digital with anyone, then you know how it goes. It starts out simple: you have your version, and you send it to your partner. They make some changes, so now there are two versions, and send the suggestions back to you. You integrate their changes into your version, and now there is one version again.
|
||||
|
||||
Then it gets worse: while you change your version further, your partner makes more changes to their version. Now you have three versions; the merged copy that you both worked on, the version you changed, and the version your partner has changed.
|
||||
|
||||
As Jason van Gumster points out in his article, 【Even artists need version control][1], this syndrome tends to happen in individual settings as well. In both art and science, it's not uncommon to develop a trial version of something; a version of your project that might make it a lot better, or that might fail miserably. So you create file names like project_justTesting.kdenlive and project_betterVersion.kdenlive, and then project_best_FINAL.kdenlive, but with the inevitable allowance for project_FINAL-alternateVersion.kdenlive, and so on.
|
||||
|
||||
Whether it's a change to a for loop or an editing change, it happens to the best of us. That is where a good version control system makes life easier.
|
||||
|
||||
### Git snapshots
|
||||
|
||||
Git takes snapshots of a project, and stores those snapshots as unique versions.
|
||||
|
||||
If you go off in a direction with your project that you decide was the wrong direction, you can just roll back to the last good version and continue along an alternate path.
|
||||
|
||||
If you're collaborating, then when someone sends you changes, you can merge those changes into your working branch, and then your collaborator can grab the merged version of the project and continue working from the new current version.
|
||||
|
||||
Git isn't magic, so conflicts do occur ("You changed the last line of the book, but I deleted that line entirely; how do we resolve that?"), but on the whole, Git enables you to manage the many potential variants of a single work, retaining the history of all the changes, and even allows for parallel versions.
|
||||
|
||||
### Git distributes
|
||||
|
||||
Working on a project on separate machines is complex, because you want to have the latest version of a project while you work, makes your own changes, and share your changes with your collaborators. The default method of doing this tends to be clunky online file sharing services, or old school email attachments, both of which are inefficient and error-prone.
|
||||
|
||||
Git is designed for distributed development. If you're involved with a project you can clone the project's Git repository, and then work on it as if it was the only copy in existence. Then, with a few simple commands, you can pull in any changes from other contributors, and you can also push your changes over to someone else. Now there is no confusion about who has what version of a project, or whose changes exist where. It is all locally developed, and pushed and pulled toward a common target (or not, depending on how the project chooses to develop).
|
||||
|
||||
### Git interfaces
|
||||
|
||||
In its natural state, Git is an application that runs in the Linux terminal. However, as it is well-designed and open source, developers all over the world have designed other ways to access it.
|
||||
|
||||
It is free, available to anyone for $0, and comes in packages on Linux, BSD, Illumos, and other Unix-like operating systems. It looks like this:
|
||||
|
||||
```
|
||||
$ git --version
|
||||
git version 2.5.3
|
||||
```
|
||||
|
||||
Probably the most well-known Git interfaces are web-based: sites like GitHub, the open source GitLab, Savannah, BitBucket, and SourceForge all offer online code hosting to maximise the public and social aspect of open source along with, in varying degrees, browser-based GUIs to minimise the learning curve of using Git. This is what the GitLab interface looks like:
|
||||
|
||||
|
||||
|
||||
Additionally, it is possible that a Git service or independent developer may even have a custom Git frontend that is not HTML-based, which is particularly handy if you don't live with a browser eternally open. The most transparent integration comes in the form of file manager support. The KDE file manager, Dolphin, can show the Git status of a directory, and even generate commits, pushes, and pulls.
|
||||
|
||||
|
||||
|
||||
[Sparkleshare][2] uses Git as a foundation for its own Dropbox-style file sharing interface.
|
||||
|
||||
|
||||
|
||||
For more, see the (long) page on the official [Git wiki][3] listing projects with graphical interfaces to Git.
|
||||
|
||||
### Who should use Git?
|
||||
|
||||
You should! The real question is when? And what for?
|
||||
|
||||
### When should I use Git, and what should I use it for?
|
||||
|
||||
To get the most out of Git, you need to think a little bit more than usual about file formats.
|
||||
|
||||
Git is designed to manage source code, which in most languages consists of lines of text. Of course, Git doesn't know if you're feeding it source code or the next Great American Novel, so as long as it breaks down to text, Git is a great option for managing and tracking versions.
|
||||
|
||||
But what is text? If you write something in an office application like Libre Office, then you're probably not generating raw text. There is usually a wrapper around complex applications like that which encapsulate the raw text in XML markup and then in a zip container, as a way to ensure that all of the assets for your office file are available when you send that file to someone else. Strangely, though, something that you might expect to be very complex, like the save files for a [Kdenlive][4] project, or an SVG from [Inkscape][5], are actually raw XML files that can easily be managed by Git.
|
||||
|
||||
If you use Unix, you can check to see what a file is made of with the file command:
|
||||
|
||||
```
|
||||
$ file ~/path/to/my-file.blah
|
||||
my-file.blah: ASCII text
|
||||
$ file ~/path/to/different-file.kra: Zip data (MIME type "application/x-krita")
|
||||
```
|
||||
|
||||
If unsure, you can view the contents of a file with the head command:
|
||||
|
||||
```
|
||||
$ head ~/path/to/my-file.blah
|
||||
```
|
||||
|
||||
If you see text that is mostly readable by you, then it is probably a file made of text. If you see garbage with some familiar text characters here and there, it is probably not made of text.
|
||||
|
||||
Make no mistake: Git can manage other formats of files, but it treats them as blobs. The difference is that in a text file, two Git snapshots (or commits, as we call them) might be, say, three lines different from each other. If you have a photo that has been altered between two different commits, how can Git express that change? It can't, really, because photographs are not made of any kind of sensible text that can just be inserted or removed. I wish photo editing were as easy as just changing some text from "<sky>ugly greenish-blue</sky>" to "<sky>blue-with-fluffy-clouds</sky>" but it truly is not.
|
||||
|
||||
People check in blobs, like PNG icons or a speadsheet or a flowchart, to Git all the time, so if you're working in Git then don't be afraid to do that. Know that it's not sensible to do that with huge files, though. If you are working on a project that does generate both text files and large blobs (a common scenario with video games, which have equal parts source code to graphical and audio assets), then you can do one of two things: either invent your own solution, such as pointers to a shared network drive, or use a Git add-on like Joey Hess's excellent [git annex][6], or the [Git-Media][7] project.
|
||||
|
||||
So you see, Git really is for everyone. It is a great way to manage versions of your files, it is a powerful tool, and it is not as scary as it first seems.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/resources/what-is-git
|
||||
|
||||
作者：[Seth Kenlon ][a]
|
||||
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
|
||||
[1]: https://opensource.com/life/16/2/version-control-isnt-just-programmers
|
||||
[2]: http://sparkleshare.org/
|
||||
[3]: https://git.wiki.kernel.org/index.php/InterfacesFrontendsAndTools#Graphical_Interfaces
|
||||
[4]: https://opensource.com/life/11/11/introduction-kdenlive
|
||||
[5]: http://inkscape.org/
|
||||
[6]: https://git-annex.branchable.com/
|
||||
[7]: https://github.com/alebedev/git-media
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,139 +0,0 @@
|
||||
Getting started with Git
|
||||
=========================
|
||||
|
||||
|
||||
>Image by : opensource.com
|
||||
|
||||
|
||||
In the introduction to this series we learned who should use Git, and what it is for. Today we will learn how to clone public Git repositories, and how to extract individual files without cloning the whole works.
|
||||
|
||||
Since Git is so popular, it makes life a lot easier if you're at least familiar with it at a basic level. If you can grasp the basics (and you can, I promise!), then you'll be able to download whatever you need, and maybe even contribute stuff back. And that, after all, is what open source is all about: having access to the code that makes up the software you run, the freedom to share it with others, and the right to change it as you please. Git makes this whole process easy, as long as you're comfortable with Git.
|
||||
|
||||
So let's get comfortable with Git.
|
||||
|
||||
### Read and write
|
||||
|
||||
Broadly speaking, there are two ways to interact with a Git repository: you can read from it, or you can write to it. It's just like a file: sometimes you open a document just to read it, and other times you open a document because you need to make changes.
|
||||
|
||||
In this article, we'll cover reading from a Git repository. We'll tackle the subject of writing back to a Git repository in a later article.
|
||||
|
||||
### Git or GitHub?
|
||||
|
||||
A word of clarification: Git is not the same as GitHub (or GitLab, or Bitbucket). Git is a command-line program, so it looks like this:
|
||||
|
||||
```
|
||||
$ git
|
||||
usage: Git [--version] [--help] [-C <path>]
|
||||
[-p | --paginate | --no-pager] [--bare]
|
||||
[--Git-dir=<path>] <command> [<args>]
|
||||
|
||||
```
|
||||
|
||||
As Git is open source, lots of smart people have built infrastructures around it which, in themselves, have become very popular.
|
||||
|
||||
My articles about Git teach pure Git first, because if you understand what Git is doing then you can maintain an indifference to what front end you are using. However, my articles also include common ways of accomplishing each task through popular Git services, since that's probably what you'll encounter first.
|
||||
|
||||
### Installing Git
|
||||
|
||||
To install Git on Linux, grab it from your distribution's software repository. BSD users should find Git in the Ports tree, in the devel section.
|
||||
|
||||
For non-open source operating systems, go to the [project site][1] and follow the instructions. Once installed, there should be no difference between Linux, BSD, and Mac OS X commands. Windows users will have to adapt Git commands to match the Windows file system, or install Cygwin to run Git natively, without getting tripped up by Windows file system conventions.
|
||||
|
||||
### Afternoon tea with Git
|
||||
|
||||
Not every one of us needs to adopt Git into our daily lives right away. Sometimes, the most interaction you have with Git is to visit a repository of code, download a file or two, and then leave. On the spectrum of getting to know Git, this is more like afternoon tea than a proper dinner party. You make some polite conversation, you get the information you need, and then you part ways without the intention of speaking again for at least another three months.
|
||||
|
||||
And that's OK.
|
||||
|
||||
Generally speaking, there are two ways to access Git: via command line, or by any one of the fancy Internet technologies providing quick and easy access through the web browser.
|
||||
|
||||
Say you want to install a trash bin for use in your terminal because you've been burned one too many times by the rm command. You've heard about Trashy, which calls itself "a sane intermediary to the rm command", and you want to look over its documentation before you install it. Lucky for you, [Trashy is hosted publicly on GitLab.com][2].
|
||||
|
||||
### Landgrab
|
||||
|
||||
The first way we'll work with this Git repository is a sort of landgrab method: we'll clone the entire thing, and then sort through the contents later. Since the repository is hosted with a public Git service, there are two ways to do this: on the command line, or through a web interface.
|
||||
|
||||
To grab an entire repository with Git, use the git clone command with the URL of the Git repository. If you're not clear on what the right URL is, the repository should tell you. GitLab gives you a copy-and-paste repository URL [for Trashy][3].
|
||||
|
||||
|
||||
|
||||
You might notice that on some services, both SSH and HTTPS links are provided. You can use SSH only if you have write permissions to the repository. Otherwise, you must use the HTTPS URL.
|
||||
|
||||
Once you have the right URL, cloning the repository is pretty simple. Just git clone the URL, and optionally name the directory to clone it into. The default behaviour is to clone the git directory to your current directory; for example, 'trashy.git' gets put in your current location as 'trashy'. I use the .clone extension as a shorthand for repositories that are read-only, and the .git extension as shorthand for repositories I can read and write, but that's not by any means an official mandate.
|
||||
|
||||
```
|
||||
$ git clone https://gitlab.com/trashy/trashy.git trashy.clone
|
||||
Cloning into 'trashy.clone'...
|
||||
remote: Counting objects: 142, done.
|
||||
remote: Compressing objects: 100% (91/91), done.
|
||||
remote: Total 142 (delta 70), reused 103 (delta 47)
|
||||
Receiving objects: 100% (142/142), 25.99 KiB | 0 bytes/s, done.
|
||||
Resolving deltas: 100% (70/70), done.
|
||||
Checking connectivity... done.
|
||||
```
|
||||
|
||||
Once the repository has been cloned successfully, you can browse files in it just as you would any other directory on your computer.
|
||||
|
||||
The other way to get a copy of the repository is through the web interface. Both GitLab and GitHub provide a snapshot of any repository in a .zip file. GitHub has a big green download button, but on GitLab, look for an inconspicuous download button on the far right of your browser window:
|
||||
|
||||
|
||||
|
||||
### Pick and choose
|
||||
|
||||
An alternate method of obtaining a file from a Git repository is to find the file you're after and pluck it right out of the repository. This method is only supported via web interfaces, which is essentially you looking at someone else's clone of a repository; you can think of it as a sort of HTTP shared directory.
|
||||
|
||||
The problem with using this method is that you might find that certain files don't actually exist in a raw Git repository, as a file might only exist in its complete form after a make command builds the file, which won't happen until you download the repository, read the README or INSTALL file, and run the command. Assuming, however, that you are sure a file does exist and you just want to go into the repository, grab it, and walk away, you can do that.
|
||||
|
||||
In GitLab and GitHub, click the Files link for a file view, view the file in Raw mode, and use your web browser's save function, e.g. in Firefox, File > Save Page As. In a GitWeb repository (a web view of personal git repositories used some who prefer to host git themselves), the Raw view link is in the file listing view.
|
||||
|
||||
|
||||
|
||||
### Best practices
|
||||
|
||||
Generally, cloning an entire Git repository is considered the right way of interacting with Git. There are a few reasons for this. Firstly, a clone is easy to keep updated with the git pull command, so you won't have to keep going back to some web site for a new copy of a file each time an improvement has been made. Secondly, should you happen to make an improvement yourself, then it is easier to submit those changes to the original author if it is all nice and tidy in a Git repository.
|
||||
|
||||
For now, it's probably enough to just practice going out and finding interesting Git repositories and cloning them to your drive. As long as you know the basics of using a terminal, then it's not hard to do. Don't know the basics of terminal usage? Give me five more minutes of your time.
|
||||
|
||||
### Terminal basics
|
||||
|
||||
The first thing to understand is that all files have a path. That makes sense; if I told you to open a file for me on a regular non-terminal day, you'd have to get to where that file is on your drive, and you'd do that by navigating a bunch of computer windows until you reached that file. For example, maybe you'd click your home directory > Pictures > InktoberSketches > monkey.kra.
|
||||
|
||||
In that scenario, we could say that the file monkeysketch.kra has the path $HOME/Pictures/InktoberSketches/monkey.kra.
|
||||
|
||||
In the terminal, unless you're doing special sysadmin work, your file paths are generally going to start with $HOME (or, if you're lazy, just the ~ character) followed by a list of folders up to the filename itself. This is analogous to whatever icons you click in your GUI to reach the file or folder.
|
||||
|
||||
If you want to clone a Git repository into your Documents directory, then you could open a terminal and run this command:
|
||||
|
||||
```
|
||||
$ git clone https://gitlab.com/foo/bar.git
|
||||
$HOME/Documents/bar.clone
|
||||
```
|
||||
|
||||
Once that is complete, you can open a file manager window, navigate to your Documents folder, and you'll find the bar.clone directory waiting for you.
|
||||
|
||||
If you want to get a little more advanced, you might revisit that repository at some later date, and try a git pull to see if there have been updates to the project:
|
||||
|
||||
```
|
||||
$ cd $HOME/Documents/bar.clone
|
||||
$ pwd
|
||||
bar.clone
|
||||
$ git pull
|
||||
```
|
||||
|
||||
For now, that's all the terminal commands you need to get started, so go out and explore. The more you do it, the better you get at it, and that is, at least give or take a vowel, the name of the game.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/7/stumbling-git
|
||||
|
||||
作者：[Seth Kenlon][a]
|
||||
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/seth
|
||||
[1]: https://git-scm.com/download
|
||||
[2]: https://gitlab.com/trashy/trashy
|
||||
[3]: https://gitlab.com/trashy/trashy.git
|
||||
|
||||
131
sources/tech/20160715 bc - Command line calculator.md
Normal file
131
sources/tech/20160715 bc - Command line calculator.md
Normal file
@ -0,0 +1,131 @@
|
||||
bc: Command line calculator
|
||||
============================
|
||||
|
||||
|
||||
|
||||
If you run a graphical desktop environment, you probably point and click your way to a calculator when you need one. The Fedora Workstation, for example, includes the Calculator tool. It features several different operating modes that allow you to do, for example, complex math or financial calculations. But did you know the command line also offers a similar calculator called bc?
|
||||
|
||||
The bc utility gives you everything you expect from a scientific, financial, or even simple calculator. What’s more, it can be scripted from the command line if needed. This allows you to use it in shell scripts, in case you need to do more complex math.
|
||||
|
||||
Because bc is used by some other system software, like CUPS printing services, it’s probably installed on your Fedora system already. You can check with this command:
|
||||
|
||||
```
|
||||
dnf list installed bc
|
||||
```
|
||||
|
||||
If you don’t see it for some reason, you can install the package with this command:
|
||||
|
||||
```
|
||||
sudo dnf install bc
|
||||
```
|
||||
|
||||
### Doing simple math with bc
|
||||
|
||||
One way to use bc is to enter the calculator’s own shell. There you can run many calculations in a row. When you enter, the first thing that appears is a notice about the program:
|
||||
|
||||
```
|
||||
$ bc
|
||||
bc 1.06.95
|
||||
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
|
||||
This is free software with ABSOLUTELY NO WARRANTY.
|
||||
For details type `warranty'.
|
||||
```
|
||||
|
||||
Now you can type in calculations or commands, one per line:
|
||||
|
||||
```
|
||||
1+1
|
||||
```
|
||||
|
||||
The calculator helpfully answers:
|
||||
|
||||
```
|
||||
2
|
||||
```
|
||||
|
||||
You can perform other commands here. You can use addition (+), subtraction (-), multiplication (*), division (/), parentheses, exponents (^), and so forth. Note that the calculator respects all expected conventions such as order of operations. Try these examples:
|
||||
|
||||
```
|
||||
(4+7)*2
|
||||
4+7*2
|
||||
```
|
||||
|
||||
To exit, send the “end of input” signal with the key combination Ctrl+D.
|
||||
|
||||
Another way is to use the echo command to send calculations or commands. Here’s the calculator equivalent of “Hello, world,” using the shell’s pipe function (|) to send output from echo into bc:
|
||||
|
||||
```
|
||||
echo '1+1' | bc
|
||||
```
|
||||
|
||||
You can send more than one calculation using the shell pipe, with a semicolon to separate entries. The results are returned on separate lines.
|
||||
|
||||
```
|
||||
echo '1+1; 2+2' | bc
|
||||
```
|
||||
|
||||
### Scale
|
||||
|
||||
The bc calculator uses the concept of scale, or the number of digits after a decimal point, in some calculations. The default scale is 0. Division operations always use the scale setting. So if you don’t set scale, you may get unexpected answers:
|
||||
|
||||
```
|
||||
echo '3/2' | bc
|
||||
echo 'scale=3; 3/2' | bc
|
||||
```
|
||||
|
||||
Multiplication uses a more complex decision for scale:
|
||||
|
||||
```
|
||||
echo '3*2' | bc
|
||||
echo '3*2.0' | bc
|
||||
```
|
||||
|
||||
Meanwhile, addition and subtraction are more as expected:
|
||||
|
||||
```
|
||||
echo '7-4.15' | bc
|
||||
```
|
||||
|
||||
### Other base number systems
|
||||
|
||||
Another useful function is the ability to use number systems other than base-10 (decimal). For instance, you can easily do hexadecimal or binary math. Use the ibase and obase commands to set input and output base systems between base-2 and base-16. Remember that once you use ibase, any number you enter is expected to be in the new declared base.
|
||||
|
||||
To do hexadecimal to decimal conversions or math, you can use a command like this. Note the hexadecimal digits above 9 must be in uppercase (A-F):
|
||||
|
||||
```
|
||||
echo 'ibase=16; A42F' | bc
|
||||
echo 'ibase=16; 5F72+C39B' | bc
|
||||
```
|
||||
|
||||
To get results in hexadecimal, set the obase as well:
|
||||
|
||||
```
|
||||
echo 'obase=16; ibase=16; 5F72+C39B' | bc
|
||||
```
|
||||
|
||||
Here’s a trick, though. If you’re doing these calculations in the shell, how do you switch back to input in base-10? The answer is to use ibase, but you must set it to the equivalent of decimal number 10 in the current input base. For instance, if ibase was set to hexadecimal, enter:
|
||||
|
||||
```
|
||||
ibase=A
|
||||
```
|
||||
|
||||
Once you do this, all input numbers are now decimal again, so you can enter obase=10 to reset the output base system.
|
||||
|
||||
### Conclusion
|
||||
|
||||
This is only the beginning of what bc can do. It also allows you to define functions, variables, and loops for complex calculations and programs. You can save these programs as text files on your system to run whenever you need. You can find numerous resources on the web that offer examples and additional function libraries. Happy calculating!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/mandatory-access-control-with-selinux-or-apparmor-linux/
|
||||
|
||||
作者：[Paul W. Frields][a]
|
||||
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/
|
||||
[1]: http://phodd.net/gnu-bc/
|
||||
@ -0,0 +1,95 @@
|
||||
Translating by chenzhijun
|
||||
|
||||
|
||||
BEST TEXT EDITORS FOR LINUX COMMAND LINE
|
||||
==========================================
|
||||
|
||||
|
||||
|
||||
A text editor is a must have application for any operating system. We have no dearth of [best modern editors for Linux][1]. But those are GUI based editors.
|
||||
|
||||
As you know, the real power of Linux lies in the command line. And when you are working in command line, you would need a text editor that could work right inside the terminal.
|
||||
|
||||
For that purpose, today we are going to make a list of best command line text editors for Linux.
|
||||
|
||||
### [VIM][2]
|
||||
|
||||
If you’re on Linux for quite some time, you must have heard about Vim. Vim is an extensively configurable, cross-platform and highly efficient text editor.
|
||||
|
||||
Almost every Linux distribution comes with Vim pre-installed. It is extremely popular for its wide range of features.
|
||||
|
||||
|
||||
>Vim User Interface
|
||||
|
||||
Vim can be quite agonizing for first-time users. I remember the first time I tried to edit a text file with Vim, I was completely puzzled. I couldn’t type a single letter on it and the funny part is, I couldn’t even figure out how to close this thing. If you are going to use Vim, you have to be determined for climbing up a very steep learning curve.
|
||||
|
||||
But after you have gone through all that, combed through some documentations, remembered its commands and shortcuts you will find that the hassle was worth it. You can bend Vim to your will – customizing its interface however it seems fit to you, give your workflow a boost by using various user scripts, plugins and so on. Vim supports syntax highlighting, macro recording and action history.
|
||||
|
||||
As in the official site, it is stated that,
|
||||
|
||||
>**Vim: The power tool for everyone!**
|
||||
|
||||
It is completely up to you how you will use it. You can just use it for simple text editing, or you can customize it to behave as a full-fledged IDE.
|
||||
|
||||
### [GNU EMACS][3]
|
||||
|
||||
GNU Emacs is undoubtedly one of the most powerful text editor out there. If you have heard about both Vim and Emacs, you should know that both of these editors have a very loyal fan-base and often they are very serious about their text editor of choice. And you can find lots of humor and stuff on the internet about it:
|
||||
|
||||
Suggested Read [Download Linux Wallpapers That Are Also Cheat Sheets][4]
|
||||
|
||||
|
||||
>Vim vs Emacs
|
||||
|
||||
Emacs is cross-platform and has both command-line and graphical user interface. It is also very rich with various features and, most importantly, extensible.
|
||||
|
||||
|
||||
>Emacs User Interface
|
||||
|
||||
Just as Vim, Emacs too comes with a steep learning curve. But once you master it, you can completely leverage its power. Emacs can handle just about any types of text files. The interface is customizable to suit your workflow. It supports macro recording and shortcuts.
|
||||
|
||||
The unique power of Emacs is that it can be transformed into something completely different from a text editor. There is a large collection of modules that can transform the application for using in completely different scenarios, like – calendar, news reader, word processor etc. You can even play games in Emacs!
|
||||
|
||||
### [NANO][5]
|
||||
|
||||
When it comes to simplicity, Nano is the one. Unlike Vim or Emacs, the learning curve for nano is almost flat.
|
||||
|
||||
If you want to simply create & edit a text file and get on with your life, look no further than Nano.
|
||||
|
||||
|
||||
>Nano User Interface
|
||||
|
||||
The shortcuts available on Nano are displayed at the bottom of the user interface. Nano includes only the basic functions of a text editor.
|
||||
|
||||
It is minimal and perfectly suitable for editing system & configuration files. For those who doesn’t need advanced features from a command-line text editor, Nano is the perfect match.
|
||||
|
||||
### OTHERS
|
||||
|
||||
There is one more editor I’d like to mention:
|
||||
|
||||
[The Nice Editor (ne)][6]: The official site says,
|
||||
|
||||
>If you have the resources and the patience to use emacs or the right mental twist to use vi then probably ne is not for you.
|
||||
|
||||
Basically, ne features many advanced features like Vim or Emacs, including – scripting and macro recording. But it comes with a more intuitive control and not so steep learning curve.
|
||||
|
||||
### WHAT DO YOU THINK?
|
||||
|
||||
I know that if you are a seasoned Linux user, you’ll say these are the obvious candidates for the list of best command line text editors for Linux. Therefore, I would like to ask you, if there are some other command line text editors for Linux that you want to share with us?
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/command-line-text-editors-linux/?utm_source=newsletter&utm_medium=email&utm_campaign=ubuntu_forums_hacked_new_skype_for_linux_and_more_linux_stories
|
||||
|
||||
作者：[Munif Tanjim][a]
|
||||
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/munif/
|
||||
[1]: https://itsfoss.com/best-modern-open-source-code-editors-for-linux/
|
||||
[2]: http://www.vim.org/
|
||||
[3]: https://www.gnu.org/software/emacs/
|
||||
[4]: https://itsfoss.com/download-linux-wallpapers-cheat-sheets/
|
||||
[5]: http://www.nano-editor.org/
|
||||
[6]: http://ne.di.unimi.it/
|
||||
@ -0,0 +1,62 @@
|
||||
maywanting
|
||||
|
||||
5 tricks for getting started with Vim
|
||||
=====================================
|
||||
|
||||
|
||||
|
||||
For years, I've wanted to learn Vim, now my preferred Linux text editor and a favorite open source tool among developers and system administrators. And when I say learn, I mean really learn. Master is probably too strong a word, but I'd settle for advanced proficiency. For most of my years using Linux, my skillset included the ability to open a file, use the arrow keys to navigate up and down, switch into insert mode, change some text, save, and exit.
|
||||
|
||||
But that's like minimum-viable-Vim. My skill level enabled me edit text documents from the terminal, but hasn't actually empowered me with any of the text editing super powers I've always imagined were possible. And it didn't justify using Vim over the totally capable Pico or Nano.
|
||||
|
||||
So why learn Vim at all? Because I do spend an awful lot of time editing text, and I know I could be more efficient at it. And why not Emacs, or a more modern editor like Atom? Because Vim works for me, and at least I have some minimal experience in it. And perhaps, importantly, because it's rare that I encounter a system that I'm working on which doesn't have Vim or it's less-improved cousin (vi) available on it already. If you've always had a desire to learn Emacs, more power to you—I hope the Emacs-analog of these tips will prove useful to you, too.
|
||||
|
||||
A few weeks in to this concentrated effort to up my Vim-use ability, the number one tip I have to share is that you actually must use the tool. While it seems like a piece of advice straight from Captain Obvious, I actually found it considerably harder than I expected to stay in the program. Most of my work happens inside of a web browser, and I had to untrain my trigger-like opening of (Gedit) every time I needed to edit a block of text outside of a browser. Gedit had made its way to my quick launcher, and so step one was removing this shortcut and putting Vim there instead.
|
||||
|
||||
I've tried a number of things that have helped me learn. Here's a few of them I would recommend if you're looking to learn as well.
|
||||
|
||||
### Vimtutor
|
||||
|
||||
Sometimes the best place to get started isn't far from the application itself. I found Vimtutor, a tiny application that is basically a tutorial in a text file that you edit as you learn, to be as helpful as anything else in showing me the basics of the commands I had skipped learning through the years. Vimtutor is typically found everywhere Vim is, and is an easy install from your package manager if it's not already on your system.
|
||||
|
||||
### GVim
|
||||
|
||||
I know not everyone will agree with this one, but I found it useful to stop using the version of Vim that lives in my terminal and start using GVim for my basic editing needs. Naysayers will argue that it encourages using the mouse in an environment designed for keyboards, but I found it helpful to be able to quickly find the command I was looking for in a drop-down menu, reminding myself of the correct command, and then executing it with a keyboard. The alternative was often frustration at the inability to figure out how to do something, which is not a good feeling to be under constantly as you struggle to learn a new editor. No, stopping every few minutes to read a man page or use a search engine to remind you of a key sequence is not the best way to learn something new.
|
||||
|
||||
### Keyboard maps
|
||||
|
||||
Along with switching to GVim, I also found it handy to have a keyboard "cheat sheet" handy to remind me of the basic keystrokes. There are many available on the web that you can download, print, and set beside your station, but I opted for buying a set of stickers for my laptop keyboard. They were less than ten dollars US and had the added bonus of being a subtle reminder every time I used the laptop to at least try out one new thing as I edited.
|
||||
|
||||
### Vimium
|
||||
|
||||
As I mentioned, I live in the web browser most of the day. One of the tricks I've found helpful to reinforce the Vim way of navigation is to use [Vimium][1], an open source extension for Chrome that makes Chrome mimick the shortcuts used by Vim. I've found the fewer times I switch contexts for the keyboard shortcuts I'm using, the more likely I am to actually use them. Similar extensions, like [Vimerator][2], exist for Firefox.
|
||||
|
||||
### Other human beings
|
||||
|
||||
Without a doubt, there's no better way to get help learning something new than to get advice, feedback, and solutions from other people who have gone down a path before you.
|
||||
|
||||
If you live in a larger urban area, there might be a Vim meetup group near you. Otherwise, the place to be is the #vim channel on Freenode IRC. One of the more popular channels on Freenode, the #vim channel is always full of helpful individuals willing to offer help with your problems. I find it interesting just to listen to the chatter and see what sorts of problems others are trying to solve to see what I'm missing out on.
|
||||
|
||||
------
|
||||
|
||||
And so what to make of this effort? So far, so good. The time spent has probably yet to pay for itself in terms of time saved, but I'm always mildly surprised and amused when I find myself with a new reflex, jumping words with the right keypress sequence, or some similarly small feat. I can at least see that every day, the investment is bringing itself a little closer to payoff.
|
||||
|
||||
These aren't the only tricks for learning Vim, by far. I also like to point people towards [Vim Adventures][3], an online game in which you navigate using the Vim keystrokes. And just the other day I came across a marvelous visual learning tool at [Vimgifs.com][4], which is exactly what you might expect it to be: illustrated examples with Vim so small they fit nicely in a gif.
|
||||
|
||||
Have you invested the time to learn Vim, or really, any program with a keyboard-heavy interface? What worked for you, and, did you think the effort was worth it? Has your productivity changed as much as you thought it would? Lets share stories in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/7/tips-getting-started-vim
|
||||
|
||||
作者：[Jason Baker ][a]
|
||||
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/jason-baker
|
||||
[1]: https://github.com/philc/vimium
|
||||
[2]: http://www.vimperator.org/
|
||||
[3]: http://vim-adventures.com/
|
||||
[4]: http://vimgifs.com/
|
||||
62
sources/tech/20160722 Keeweb A Linux Password Manager.md
Normal file
62
sources/tech/20160722 Keeweb A Linux Password Manager.md
Normal file
@ -0,0 +1,62 @@
|
||||
Keeweb A Linux Password Manager
|
||||
================================
|
||||
|
||||
|
||||
|
||||
Today we are depending on more and more online services. Each online service we sign up for, let us set a password and this way we have to remember hundreds of passwords. In this case, it is easy for anyone to forget passwords. In this article I am going to talk about Keeweb, a Linux password manager that can store all your passwords securely either online or offline.
|
||||
|
||||
When we talk about Linux password managers, there are so many. Password managers like, [Keepass][1] and [Encryptr, a Zero-knowledge system based password manager][2] have already been talked about on LinuxAndUbuntu. Keeweb is another password manager for Linux that we are going to see in this article.
|
||||
|
||||
### Keeweb can store passwords offline or online
|
||||
|
||||
Keeweb is a cross-platform password manager. It can store all your passwords offline and sync it with your own cloud storage services like OneDrive, Google Drive, Dropbox etc. Keeweb does not have online database of its own to sync your passwords.
|
||||
|
||||
To connect your online storage with Keeweb, just click more and click the service that you want to use.
|
||||
|
||||
|
||||
|
||||
Now Keeweb will prompt you to sign in to your drive. After sign in authenticate Keeweb to use your account.
|
||||
|
||||
|
||||
|
||||
### Store passwords with Keeweb
|
||||
|
||||
It is very easy to store your passwords with Keeweb. You can encrypt your password file with a complex password. Keeweb also allows you to lock file with a key file but I don't recommend it. If somebody gets your key file, it takes only a click to unlock your passwords file.
|
||||
|
||||
#### Create Passwords
|
||||
|
||||
To create a new password simply click the '+' sign and you will be presented all entries to fill up. You can create more entries if you want.
|
||||
|
||||
#### Search Passwords
|
||||
|
||||
|
||||
|
||||
Keeweb has a library of icons so that you can find any particular password entry easily. You can change the color of icons, download more icons and even import icons from your computer. When talking about finding passwords the search comes very handy.
|
||||
|
||||
Passwords of similar services can be grouped so that you can find them all at one place in one folder. You can also tag passwords to store them all in different categories.
|
||||
|
||||
|
||||
|
||||
### Themes
|
||||
|
||||
|
||||
|
||||
If you like light themes like white or high contrast then you can change theme from Settings > General > Themes. There are four themes available, two are dark and two are light.
|
||||
|
||||
### Dont' you Like Linux Passwords Manager? No problem!
|
||||
|
||||
I have already posted about two other Linux password managers, Keepass and Encryptr and there were arguments on Reddit, and other social media. There were people against using any password manager and vice-versa. In this article I want to clear out that it is our responsibility to save the file that passwords are stored in. I think Password managers like Keepass and Keeweb are good to use as they don't store your passwords in the cloud. These password managers create a file and you can store it on your hard drive or encrypt it with apps like VeraCrypt. I myself don't use or recommend to use services that store passwords in their own database.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/mandatory-access-control-with-selinux-or-apparmor-linux/
|
||||
|
||||
作者：[author][a]
|
||||
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]: http://www.linuxandubuntu.com/home/keeweb-a-linux-password-manager
|
||||
[1]: http://www.linuxandubuntu.com/home/keepass-password-management-tool-creates-strong-passwords-and-keeps-them-secure
|
||||
[2]: http://www.linuxandubuntu.com/home/encryptr-zero-knowledge-system-based-password-manager-for-linux
|
||||
@ -0,0 +1,85 @@
|
||||
Terminator A Linux Terminal Emulator With Multiple Terminals In One Window
|
||||
=============================================================================
|
||||
|
||||
|
||||
|
||||
Each Linux distribution has a default terminal emulator for interacting with system through commands. But the default terminal app might not be perfect for you. There are so many terminal apps that will provide you more functionalities to perform more tasks simultaneously to sky-rocket speed of your work. Such useful terminal emulators include Terminator, a multi-windows supported free terminal emulator for your Linux system.
|
||||
|
||||
### What Is Linux Terminal Emulator?
|
||||
|
||||
A Linux terminal emulator is a program that lets you interact with the shell. All Linux distributions come with a default Linux terminal app that let you pass commands to the shell.
|
||||
|
||||
### Terminator, A Free Linux Terminal App
|
||||
|
||||
Terminator is a Linux terminal emulator that provides several features that your default terminal app does not support. It provides the ability to create multiple terminals in one window and faster your work progress. Other than multiple windows, it allows you to change other properties such as, terminal fonts, fonts colour, background colour and so on. Let's see how we can install and use Terminator in different Linux distributions.
|
||||
|
||||
### How To Install Terminator In Linux?
|
||||
|
||||
#### Install Terminator In Ubuntu Based Distributions
|
||||
|
||||
Terminator is available in the default Ubuntu repository. So you don't require to add any additional PPA. Just use APT or Software App to install it in Ubuntu.
|
||||
|
||||
```
|
||||
sudo apt-get install terminator
|
||||
```
|
||||
|
||||
In case Terminator is not available in your default repository, just compile Terminator from source code.
|
||||
|
||||
[DOWNLOAD SOURCE CODE][1]
|
||||
|
||||
Download Terminator source code and extract it on your desktop. Now open your default terminal & cd into the extracted folder.
|
||||
|
||||
Now use the following command to install Terminator -
|
||||
|
||||
```
|
||||
sudo ./setup.py install
|
||||
```
|
||||
|
||||
#### Install Terminator In Fedora & Other Derivatives
|
||||
|
||||
```
|
||||
dnf install terminator
|
||||
```
|
||||
|
||||
#### Install Terminator In OpenSuse
|
||||
|
||||
[INSTALL IN OPENSUSE][2]
|
||||
|
||||
### How To Use Multiple Terminals In One Window?
|
||||
|
||||
After you have installed Terminator, simply open multiple terminals in one window. Simply right click and divide.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
You can create as many terminals as you want, if you can manage them.
|
||||
|
||||
|
||||
|
||||
### Customise Terminals
|
||||
|
||||
Right click the terminal and click Properties. Now you can customise fonts, fonts colour, title colour & background and terminal fonts colour & background.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
### Conclusion & What Is Your Favorite Terminal Emulator?
|
||||
|
||||
Terminator is an advanced terminal emulator and it also let you customize the interface. If you have not yet switched from your default terminal emulator then just try this one. I know you'll like it. If you're using any other free terminal emulator, then let us know your favorite terminal emulator. Also don't forget to share this article with your friends. Perhaps your friends are searching for something like this.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/mandatory-access-control-with-selinux-or-apparmor-linux/
|
||||
|
||||
作者：[author][a]
|
||||
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]: http://www.linuxandubuntu.com/home/terminator-a-linux-terminal-emulator-with-multiple-terminals-in-one-window
|
||||
[1]: https://launchpad.net/terminator/+download
|
||||
[2]: http://software.opensuse.org/download.html?project=home%3AKorbi123&package=terminator
|
||||
@ -0,0 +1,220 @@
|
||||
translating---geekpi
|
||||
|
||||
How to use multiple connections to speed up apt-get/apt on Ubuntu Linux 16.04 LTS server
|
||||
=========================================================================================
|
||||
|
||||
ow do I speed up my apt-get or apt command to download packages from multiple repos on a Ubuntu Linux 16.04 or 14.04 LTS server?
|
||||
|
||||
You need to use apt-fast shell script wrapper. It should speed up apt-get command/apt command and aptitude command by downloading packages with multiple connections per package. All packages are downloaded simultaneously in parallel. It uses aria2c as default download accelerator.
|
||||
|
||||
### Install apt-fast tool
|
||||
|
||||
Type the following command on Ubuntu Linux 14.04 and later versions:
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:saiarcot895/myppa
|
||||
```
|
||||
|
||||
Sample outputs:
|
||||
|
||||
|
||||
|
||||
Update your repo:
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
```
|
||||
|
||||
OR
|
||||
|
||||
```
|
||||
$ sudo apt update
|
||||
```
|
||||
|
||||
|
||||
|
||||
Install apt-fast shell wrapper:
|
||||
|
||||
```
|
||||
$ sudo apt-get -y install apt-fast
|
||||
```
|
||||
|
||||
OR
|
||||
|
||||
```
|
||||
$ sudo apt -y install apt-fast
|
||||
```
|
||||
|
||||
Sample outputs:
|
||||
|
||||
|
||||
```
|
||||
Reading package lists... Done
|
||||
Building dependency tree
|
||||
Reading state information... Done
|
||||
The following additional packages will be installed:
|
||||
aria2 libc-ares2 libssh2-1
|
||||
Suggested packages:
|
||||
aptitude
|
||||
The following NEW packages will be installed:
|
||||
apt-fast aria2 libc-ares2 libssh2-1
|
||||
0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
|
||||
Need to get 1,282 kB of archives.
|
||||
After this operation, 4,786 kB of additional disk space will be used.
|
||||
Do you want to continue? [Y/n] y
|
||||
Get:1 http://01.archive.ubuntu.com/ubuntu xenial/universe amd64 libssh2-1 amd64 1.5.0-2 [70.3 kB]
|
||||
Get:2 http://ppa.launchpad.net/saiarcot895/myppa/ubuntu xenial/main amd64 apt-fast all 1.8.3~137+git7b72bb7-0ubuntu1~ppa3~xenial1 [34.4 kB]
|
||||
Get:3 http://01.archive.ubuntu.com/ubuntu xenial/main amd64 libc-ares2 amd64 1.10.0-3 [33.9 kB]
|
||||
Get:4 http://01.archive.ubuntu.com/ubuntu xenial/universe amd64 aria2 amd64 1.19.0-1build1 [1,143 kB]
|
||||
54% [4 aria2 486 kB/1,143 kB 42%] 20.4 kB/s 32s
|
||||
```
|
||||
|
||||
### Configure apt-fast
|
||||
|
||||
You will be prompted as follows (a value between 5 and 16 must be entered):
|
||||
|
||||
|
||||
|
||||
And:
|
||||
|
||||
|
||||
|
||||
You can edit settings directly too:
|
||||
|
||||
```
|
||||
$ sudo vi /etc/apt-fast.conf
|
||||
```
|
||||
|
||||
>**Please note that this tool is not for slow network connections; it is for fast network connections. If you have a slow connection to the Internet, you are not going to benefit by this tool.**
|
||||
|
||||
### How do I use apt-fast command?
|
||||
|
||||
The syntax is:
|
||||
|
||||
```
|
||||
apt-fast command
|
||||
apt-fast [options] command
|
||||
```
|
||||
|
||||
#### To retrieve new lists of packages using apt-fast
|
||||
|
||||
```
|
||||
sudo apt-fast update
|
||||
```
|
||||
|
||||
#### To perform an upgrade using apt-fast
|
||||
|
||||
```
|
||||
sudo apt-fast upgrade
|
||||
```
|
||||
|
||||
|
||||
#### To perform distribution upgrade (release or force kernel upgrade), enter:
|
||||
|
||||
```
|
||||
$ sudo apt-fast dist-upgrade
|
||||
```
|
||||
|
||||
#### To install new packages
|
||||
|
||||
The syntax is:
|
||||
|
||||
```
|
||||
sudo apt-fast install pkg
|
||||
```
|
||||
|
||||
For example, install nginx package, enter:
|
||||
|
||||
```
|
||||
$ sudo apt-fast install nginx
|
||||
```
|
||||
|
||||
Sample outputs:
|
||||
|
||||
|
||||
|
||||
#### To remove packages
|
||||
|
||||
```
|
||||
$ sudo apt-fast remove pkg
|
||||
$ sudo apt-fast remove nginx
|
||||
```
|
||||
|
||||
#### To remove packages and its config files too
|
||||
|
||||
```
|
||||
$ sudo apt-fast purge pkg
|
||||
$ sudo apt-fast purge nginx
|
||||
```
|
||||
|
||||
#### To remove automatically all unused packages, enter:
|
||||
|
||||
```
|
||||
$ sudo apt-fast autoremove
|
||||
```
|
||||
|
||||
#### To Download source archives
|
||||
|
||||
```
|
||||
$ sudo apt-fast source pkgNameHere
|
||||
```
|
||||
|
||||
#### To erase downloaded archive files
|
||||
|
||||
```
|
||||
$ sudo apt-fast clean
|
||||
```
|
||||
|
||||
#### To erase old downloaded archive files
|
||||
|
||||
```
|
||||
$ sudo apt-fast autoclean
|
||||
```
|
||||
|
||||
#### To verify that there are no broken dependencies
|
||||
|
||||
```
|
||||
$ sudo apt-fast check
|
||||
```
|
||||
|
||||
#### To download the binary package into the current directory
|
||||
|
||||
```
|
||||
$ sudo apt-fast download pkgNameHere
|
||||
$ sudo apt-fast download nginx
|
||||
```
|
||||
|
||||
Sample outputs:
|
||||
|
||||
```
|
||||
[#7bee0c 0B/0B CN:1 DL:0B]
|
||||
07/26 15:35:42 [NOTICE] Verification finished successfully. file=/home/vivek/nginx_1.10.0-0ubuntu0.16.04.2_all.deb
|
||||
07/26 15:35:42 [NOTICE] Download complete: /home/vivek/nginx_1.10.0-0ubuntu0.16.04.2_all.deb
|
||||
Download Results:
|
||||
gid |stat|avg speed |path/URI
|
||||
======+====+===========+=======================================================
|
||||
7bee0c|OK | n/a|/home/vivek/nginx_1.10.0-0ubuntu0.16.04.2_all.deb
|
||||
Status Legend:
|
||||
(OK):download completed.
|
||||
```
|
||||
|
||||
#### To download and display the changelog for the given package
|
||||
|
||||
```
|
||||
$ sudo apt-fast changelog pkgNameHere
|
||||
$ sudo apt-fast changelog nginx
|
||||
```
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/introducing-flatpak/
|
||||
|
||||
作者：[VIVEK GITE][a]
|
||||
译者：[zky001](https://github.com/zky001)
|
||||
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]: http://www.cyberciti.biz/tips/about-us
|
||||
@ -1,3 +1,5 @@
|
||||
Being translated by ChrisLeeGit
|
||||
|
||||
Part 13 - LFCS: How to Configure and Troubleshoot Grand Unified Bootloader (GRUB)
|
||||
=====================================================================================
|
||||
|
||||
@ -167,7 +169,7 @@ Do you have questions or comments? Don’t hesitate to let us know using the com
|
||||
via: http://www.tecmint.com/linux-basic-shell-scripting-and-linux-filesystem-troubleshooting/
|
||||
|
||||
作者：[Gabriel Cánepa][a]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
译者：[ChrisLeeGit](https://github.com/chrisleegit)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
@ -0,0 +1,275 @@
|
||||
translating by vim-kakali
|
||||
|
||||
|
||||
Learn How to Use Awk Variables, Numeric Expressions and Assignment Operators – part8
|
||||
|
||||
=======================================================================================
|
||||
|
||||
The [Awk command series][1] is getting exciting I believe, in the previous seven parts, we walked through some fundamentals of Awk that you need to master to enable you perform some basic text or string filtering in Linux.
|
||||
|
||||
Starting with this part, we shall dive into advance areas of Awk to handle more complex text or string filtering operations. Therefore, we are going to cover Awk features such as variables, numeric expressions and assignment operators.
|
||||
|
||||
|
||||
>Learn Awk Variables, Numeric Expressions and Assignment Operators
|
||||
|
||||
These concepts are not comprehensively distinct from the ones you may have probably encountered in many programming languages before such shell, C, Python plus many others, so there is no need to worry much about this topic, we are simply revising the common ideas of using these mentioned features.
|
||||
|
||||
This will probably be one of the easiest Awk command sections to understand, so sit back and lets get going.
|
||||
|
||||
### 1. Awk Variables
|
||||
|
||||
In any programming language, a variable is a place holder which stores a value, when you create a variable in a program file, as the file is executed, some space is created in memory that will store the value you specify for the variable.
|
||||
|
||||
You can define Awk variables in the same way you define shell variables as follows:
|
||||
|
||||
```
|
||||
variable_name=value
|
||||
```
|
||||
|
||||
In the syntax above:
|
||||
|
||||
- `variable_name`: is the name you give a variable
|
||||
- `value`: the value stored in the variable
|
||||
|
||||
Let’s look at some examples below:
|
||||
|
||||
```
|
||||
computer_name=”tecmint.com”
|
||||
port_no=”22”
|
||||
email=”admin@tecmint.com”
|
||||
server=”computer_name”
|
||||
```
|
||||
|
||||
Take a look at the simple examples above, in the first variable definition, the value `tecmint.com` is assigned to the variable `computer_name`.
|
||||
|
||||
Furthermore, the value 22 is assigned to the variable port_no, it is also possible to assign the value of one variable to another variable as in the last example where we assigned the value of computer_name to the variable server.
|
||||
|
||||
If you can recall, right from [part 2 of this Awk series][2] were we covered field editing, we talked about how Awk divides input lines into fields and uses standard field access operator, $ to read the different fields that have been parsed. We can also use variables to store the values of fields as follows.
|
||||
|
||||
```
|
||||
first_name=$2
|
||||
second_name=$3
|
||||
```
|
||||
|
||||
In the examples above, the value of first_name is set to second field and second_name is set to the third field.
|
||||
|
||||
As an illustration, consider a file named names.txt which contains a list of an application’s users indicating their first and last names plus gender. Using the [cat command][3], we can view the contents of the file as follows:
|
||||
|
||||
```
|
||||
$ cat names.txt
|
||||
```
|
||||
|
||||
|
||||
>List File Content Using cat Command
|
||||
|
||||
Then, we can also use the variables first_name and second_name to store the first and second names of the first user on the list as by running the Awk command below:
|
||||
|
||||
```
|
||||
$ awk '/Aaron/{ first_name=$2 ; second_name=$3 ; print first_name, second_name ; }' names.txt
|
||||
```
|
||||
|
||||
|
||||
>Store Variables Using Awk Command
|
||||
|
||||
Let us also take a look at another case, when you issue the command `uname -a` on your terminal, it prints out all your system information.
|
||||
|
||||
The second field contains your `hostname`, therefore we can store the hostname in a variable called hostname and print it using Awk as follows:
|
||||
|
||||
```
|
||||
$ uname -a
|
||||
$ uname -a | awk '{hostname=$2 ; print hostname ; }'
|
||||
```
|
||||
|
||||
|
||||
>Store Command Output to Variable Using Awk
|
||||
|
||||
### 2. Numeric Expressions
|
||||
|
||||
In Awk, numeric expressions are built using the following numeric operators:
|
||||
|
||||
- `*` : multiplication operator
|
||||
- `+` : addition operator
|
||||
- `/` : division operator
|
||||
- `-` : subtraction operator
|
||||
- `%` : modulus operator
|
||||
- `^` : exponentiation operator
|
||||
|
||||
The syntax for a numeric expressions is:
|
||||
|
||||
```
|
||||
$ operand1 operator operand2
|
||||
```
|
||||
|
||||
In the form above, operand1 and operand2 can be numbers or variable names, and operator is any of the operators above.
|
||||
|
||||
Below are some examples to demonstrate how to build numeric expressions:
|
||||
|
||||
```
|
||||
counter=0
|
||||
num1=5
|
||||
num2=10
|
||||
num3=num2-num1
|
||||
counter=counter+1
|
||||
```
|
||||
|
||||
To understand the use of numeric expressions in Awk, we shall consider the following example below, with the file domains.txt which contains all domains owned by Tecmint.
|
||||
|
||||
```
|
||||
news.tecmint.com
|
||||
tecmint.com
|
||||
linuxsay.com
|
||||
windows.tecmint.com
|
||||
tecmint.com
|
||||
news.tecmint.com
|
||||
tecmint.com
|
||||
linuxsay.com
|
||||
tecmint.com
|
||||
news.tecmint.com
|
||||
tecmint.com
|
||||
linuxsay.com
|
||||
windows.tecmint.com
|
||||
tecmint.com
|
||||
```
|
||||
|
||||
To view the contents of the file, use the command below:
|
||||
|
||||
```
|
||||
$ cat domains.txt
|
||||
```
|
||||
|
||||
|
||||
>View Contents of File
|
||||
|
||||
If we want to count the number of times the domain tecmint.com appears in the file, we can write a simple script to do that as follows:
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
for file in $@; do
|
||||
if [ -f $file ] ; then
|
||||
#print out filename
|
||||
echo "File is: $file"
|
||||
#print a number incrementally for every line containing tecmint.com
|
||||
awk '/^tecmint.com/ { counter=counter+1 ; printf "%s\n", counter ; }' $file
|
||||
else
|
||||
#print error info incase input is not a file
|
||||
echo "$file is not a file, please specify a file." >&2 && exit 1
|
||||
fi
|
||||
done
|
||||
#terminate script with exit code 0 in case of successful execution
|
||||
exit 0
|
||||
```
|
||||
|
||||
|
||||
>Shell Script to Count a String or Text in File
|
||||
|
||||
After creating the script, save it and make it executable, when we run it with the file, domains.txt as out input, we get the following output:
|
||||
|
||||
```
|
||||
$ ./script.sh ~/domains.txt
|
||||
```
|
||||
|
||||
|
||||
>Script to Count String or Text
|
||||
|
||||
From the output of the script, there are 6 lines in the file domains.txt which contain tecmint.com, to confirm that you can manually count them.
|
||||
|
||||
### 3. Assignment Operators
|
||||
|
||||
The last Awk feature we shall cover is assignment operators, there are several assignment operators in Awk and these include the following:
|
||||
|
||||
- `*=` : multiplication assignment operator
|
||||
- `+=` : addition assignment operator
|
||||
- `/=` : division assignment operator
|
||||
- `-=` : subtraction assignment operator
|
||||
- `%=` : modulus assignment operator
|
||||
- `^=` : exponentiation assignment operator
|
||||
|
||||
The simplest syntax of an assignment operation in Awk is as follows:
|
||||
|
||||
```
|
||||
$ variable_name=variable_name operator operand
|
||||
```
|
||||
|
||||
Examples:
|
||||
|
||||
```
|
||||
counter=0
|
||||
counter=counter+1
|
||||
num=20
|
||||
num=num-1
|
||||
```
|
||||
|
||||
You can use the assignment operators above to shorten assignment operations in Awk, consider the previous examples, we could perform the assignment in the following form:
|
||||
|
||||
```
|
||||
variable_name operator=operand
|
||||
counter=0
|
||||
counter+=1
|
||||
num=20
|
||||
num-=1
|
||||
```
|
||||
|
||||
Therefore, we can alter the Awk command in the shell script we just wrote above using += assignment operator as follows:
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
for file in $@; do
|
||||
if [ -f $file ] ; then
|
||||
#print out filename
|
||||
echo "File is: $file"
|
||||
#print a number incrementally for every line containing tecmint.com
|
||||
awk '/^tecmint.com/ { counter+=1 ; printf "%s\n", counter ; }' $file
|
||||
else
|
||||
#print error info incase input is not a file
|
||||
echo "$file is not a file, please specify a file." >&2 && exit 1
|
||||
fi
|
||||
done
|
||||
#terminate script with exit code 0 in case of successful execution
|
||||
exit 0
|
||||
```
|
||||
|
||||
|
||||
|
||||
>Alter Shell Script
|
||||
|
||||
In this segment of the [Awk series][4], we covered some powerful Awk features, that is variables, building numeric expressions and using assignment operators, plus some few illustrations of how we can actually use them.
|
||||
|
||||
These concepts are not any different from the one in other programming languages but there may be some significant distinctions under Awk programming.
|
||||
|
||||
In part 9, we shall look at more Awk features that is special patterns: BEGIN and END. Until then, stay connected to Tecmint.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/learn-awk-variables-numeric-expressions-and-assignment-operators/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对ID](https://github.com/校对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]: http://www.tecmint.com/author/aaronkili/
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
[1]: http://www.tecmint.com/category/awk-command/
|
||||
[2]: http://www.tecmint.com/awk-print-fields-columns-with-space-separator/
|
||||
[3]: http://www.tecmint.com/13-basic-cat-command-examples-in-linux/
|
||||
[4]: http://www.tecmint.com/category/awk-command/
|
||||
@ -1,80 +0,0 @@
|
||||
Translated by FrankXinqi
|
||||
|
||||
Linus Torvalds作为一个老板有多么糟糕？
|
||||
================================================================================
|
||||
|
||||
|
||||
*1999 年 8 月 10 日，加利福尼亚州圣何塞市，在 LinuxWorld Show 上 Linus Torvalds 在一个坐满 Linux 爱好者的礼堂中发表了一篇演讲。作者：James Niccolai*
|
||||
|
||||
**这取决于所处的领域。在软件开发的世界中，他变得更加平庸。问题是，这种情况是否应该被允许继续？**
|
||||
|
||||
Linus Torvalds 是 Linux 的发明者，我认识他超过 20 年了。我们不是密友，但是我们欣赏彼此。
|
||||
|
||||
最近，因为 Linus Torvalds 的管理风格，他正遭到严厉的炮轰。Linus 无法忍受胡来的人。「代码的质量有多好？」是他在 Linux 内核的开发过程中评判人的一种方式。
|
||||
|
||||
没有什么比这个更重要了。正如 Linus 今年（1999年）早些时候在 Linux.conf.au 会议上说的那样，「我不是一个友好的人，并且我不关心你。对我重要的是『[我所关心的技术和内核][1]』。」
|
||||
|
||||
现在我也可以和这只关心技术的这一类人打交道了。如果你不能，你应当避免参加 Linux 内核会议，因为在那里你会遇到许多有这种精英思想的人。这不代表我认为在 Linux 领域所有东西都是极好的，并且应该不受其他影响的来激起改变。我能够一起生活的一个精英；在一个男性做主导的大城堡中遇到的问题是，女性经常受到蔑视和无礼的对待。
|
||||
|
||||
这就是我看到的最近关于 Linus 管理风格所引发社会争吵的原因 -- 或者更准确的说，他对于个人管理方面是完全冷漠的 -- 就像不过是在软件开发世界的标准操作流程一样。与此同时，我看到了另外一个非常需要被改变的事实，它必须作为证据公开。
|
||||
|
||||
第一次是在 [Linux 4.3 发布][2]的时候出现的这个情况，Linus 使用 Linux 内核邮件列表来狠狠的攻击一个插入了非常糟糕并且没有价值的网络代码的开发者。「[这段代码导致了非常糟糕并且没有价值的代码。][3]这看起来太糟糕了，并且完全没有理由这样做。」当他说到这里的时候，他沉默了很长时间。除了使用「非常糟糕并且没有价值」这个词，他在早期使用「愚蠢的」这个同义词是相对较好的。
|
||||
|
||||
但是，事情就是这样。Linus 是对的。我读了代码后，发现代码确实很烂并且开发者是为了使用新的「overflow_usub()」 函数而使用的。
|
||||
|
||||
现在，一些人把 Linus 的这种谩骂的行为看作他脾气不好而且恃强凌弱的证据。我见过一个完美主义者，在他的领域中，他无法忍受这种糟糕。
|
||||
|
||||
许多人告诉我，这不是一个专业的程序员应当有的行为。人们，你曾经和最优秀的开发者一起工作过吗？据我所知道的，在 Apple，Microsoft，Oracle 这就是他们的行为。
|
||||
|
||||
我曾经听过 Steve Jobs 攻击一个开发者，像把他撕成碎片那样。我大为不快，当一个 Oracle 的高级开发者攻击一屋子的新开发者的时候就像食人鱼穿过一群金鱼那样。
|
||||
|
||||
在意外的电脑帝国，在 Robert X. Cringely 关于 PCs 崛起的经典书籍中，他这样描述 Bill Gates 的微软软件管理风格，Bill Gates 像计算机系统一样管理他们，『比尔盖茨是最高等级，从他开始每一个等级依次递减，上级会向下级叫嚷，刺激他们，甚至羞辱他们。』
|
||||
|
||||
Linus 和所有大型的私有软件公司的领导人不同的是，Linus 说在这里所有的东西是向全世界公开的。而其他人是在私有的会议室中做东西的。我听有人说 Linus 在那种公司中可能会被开除。这是不可能的。他会在正确的地方就像现在这样，他在编程世界的最顶端。
|
||||
|
||||
但是，这里有另外一个不同。如果 Larry Ellison （Oracle的首席执行官）向你发火，你就别想在这里干了。如果 Linus 向你发火，你会在邮件中收到他的责骂。这就是差别。
|
||||
|
||||
你知道的，Linus 不是任何人的老板。他完全没有雇佣和解聘的权利，他只是负责着有 10,000 个贡献者的一个项目而已。他仅仅能做的就是从心理上伤害你。
|
||||
|
||||
这说明，在开源软件开发圈和私有软件开发圈中同时存在一个非常严重的问题。不管你是一个多么好的编程者，如果你是一个女性，你的这个身份就是对你不利的。
|
||||
|
||||
这种情况并没有在 Sarah Sharp 的身上有任何好转，她现在是一个Intel的开发者，以前是一个顶尖的Linux程序员。[在她博客10月份的一个帖子中][4]，她解释道：『我最终发现，我不能够再为Linux社区做出贡献了。因为在在那里，我虽然能够得到技术上的尊重，却得不到个人的尊重……我不想专职于同那些轻微的性别歧视者或开同性恋玩笑的人一起工作。』
|
||||
|
||||
谁能责怪她呢？我不能。我非常伤心的说，Linus 就像所有我见过的软件经理一样，是他造成了这种不利的工作环境。
|
||||
|
||||
他可能会说，确保 Linux 的贡献者都表现出专业精神和相互尊重不应该是他的工作。除了代码以外，他不关系任何其他事情。
|
||||
|
||||
就像Sarah Sharp写的那样：
|
||||
|
||||
|
||||
> 我对于 Linux 内核社区做出的技术努力表现出非常的尊重。他们在那维护一些最高标准的代码，以此来平衡并且发展一个项目。他们专注于优秀的技术，却带有过量的维护人员，他们有不同的文化背景和社会规范，这些意味着这些 Linux 内核维护者说话非常直率，粗鲁或者为了完成他们的任务而不讲道理。顶尖的 Linux 内核开发者经常为了使别人改正行为而向他们大喊大叫。
|
||||
>
|
||||
> 这种事情发生在我身上，但它不是一种有效的沟通方式。
|
||||
>
|
||||
> 许多高级的 Linux 内核开发者支持那些技术上和人性上不讲道理的维护者的权利。即使他们是非常友好的人，他们不想看到 Linux 内核交流方式改变。
|
||||
|
||||
她是对的。
|
||||
|
||||
我和其他调查者不同的是，我不认为这个问题对于 Linux 或开源社区在任何方面有特殊之处。作为一个从事技术商业工作超过五年和有着 25 年技术工作经历的记者，我随处可见这种不成熟的男孩的行为。
|
||||
|
||||
这不是 Linus 的错误。他不是一个经理，他是一个有想象力的技术领导者。看起来真正的问题是，在软件开发领域没有人能够用一种支持的语气来对待团队和社区。
|
||||
|
||||
展望未来，我希望像 Linux Foundation 这样的公司和组织，能够找到一种方式去授权社区经理或其他经理来鼓励并且强制实施民主的行为。
|
||||
|
||||
非常遗憾的是，我们不能够在我们这种纯技术或纯商业的领导人中找到这种管理策略。它不存在于这些人的基因中。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.computerworld.com/article/3004387/it-management/how-bad-a-boss-is-linus-torvalds.html
|
||||
|
||||
作者：[Steven J. Vaughan-Nichols][a]
|
||||
译者：[FrankXinqi](https://github.com/FrankXinqi)
|
||||
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]:http://www.computerworld.com/author/Steven-J.-Vaughan_Nichols/
|
||||
[1]:http://www.computerworld.com/article/2874475/linus-torvalds-diversity-gaffe-brings-out-the-best-and-worst-of-the-open-source-world.html
|
||||
[2]:http://www.zdnet.com/article/linux-4-3-released-after-linus-torvalds-scraps-brain-damage-code/
|
||||
[3]:http://lkml.iu.edu/hypermail/linux/kernel/1510.3/02866.html
|
||||
[4]:http://sarah.thesharps.us/2015/10/05/closing-a-door/
|
||||
@ -0,0 +1,48 @@
|
||||
|
||||
Linus Torvalds 谈及物联网，智能设备，安全连接等问题[video]
|
||||
===========================================================================
|
||||
|
||||
|
||||
>Dirk Hohndel 在嵌入式大会上采访 Linus Torvalds 。
|
||||
|
||||
|
||||
[嵌入式大会（Embedded Linux Conference）][0] 从在 San Diego 【译注：圣迭戈，美国加利福尼亚州的一个太平洋沿岸城市。】开始举办到现在已经有 11 年了，在 4 月 4 日到 6 日，Linus Torvalds 加入了会议的主题讨论。他是 Linux 内核的缔造者和最高决策者，也是“我们都在这里的原因”，在采访他的对话中，英特尔的 Linux 和开源技术总监 Dirk Hohndel 谈到了 Linux 在嵌入式和物联网应用程序领域的快速发展前景。Torvalds 很少出席嵌入式 Linux 大会，这些大会经常被 Linux 桌面、服务器和云技术夺去光芒。
|
||||
|
||||
>Linus Torvalds 在嵌入式 Linux 大会上的演讲。
|
||||
|
||||
|
||||
物联网是嵌入式大会的主题，也包括未来开放物联网的最高发展方向（OpenIoT Summit），这是采访 Torvalds 的主要话题。
|
||||
|
||||
Torvalds 对 Hohndel 说到，“或许你不会在物联网设备上看到 Linux 的影子，但是在你有一个核心设备的时候，你就会需要它。你需要智能设备尤其在你有 23 [物联网标准]的时候。如果你全部使用低级设备，它们没必要一定运行 Linux ,它们采用的标准稍微有点不同，所以你需要很多智能设备。我们将来也不会有一个完全开放的标准，只是给它一个统一的标准，但是你将会需要 4 分之 3 的主要协议，它们都是这些智能核心的转化形式。”
|
||||
|
||||
当 Hohndel 问及在物联网的巨大安全漏洞的时候， Torvalds 神情如常。他说：“我不担心安全问题因为我们能做的不是很多，物联网如果遭受攻击是无法挽回的－这是事实。"
|
||||
|
||||
Linux 缔造者看起来更关心的是一次性的嵌入式项目缺少及时的上游贡献，尽管他注意到近年来这些都有一些本质上的提升，特别是在硬件上的发展。
|
||||
|
||||
Torvalds 说：”嵌入式领域历来就很难与开源开发者有所联系，但是我认为这些都在发生改变，ARM 团队也已经很优秀了。内核维护者事实上也看到了硬件性能的提升。一切都在变好，但是昨天却不是这样的。”
|
||||
|
||||
Torvalds 承认他在家经常使用桌面系统而不是嵌入式系统，并且在使用硬件的时候他有“两只左手”。
|
||||
|
||||
“我已经用电烙铁弄坏了很多东西。”他说到。“我真的不适合搞硬件开发。”；另一方面，Torvalds 设想如果他现在是个年轻人，他可能被 Raspberry Pi（树莓派） 和 BeagleBone（猎兔犬板）【译注:Beagle板实际是由TI支持的一个以教育（STEP）为目的的开源项目】欺骗。“最主要是原因是如果你善于焊接，那么你就仅仅是买到了一个新的板子。”
|
||||
|
||||
同时，Torvalds 也承诺他要为 Linux 桌面再奋斗一个 25 年。他笑着说：“我要为它工作一生。”
|
||||
|
||||
下面，请看完整视频。
|
||||
|
||||
获取关于嵌入式 Linux 和物联网的最新信息。进入 2016 年嵌入式 Linux 大会 150+ 分钟的会议全程。[现在观看][1].
|
||||
[video](https://youtu.be/tQKUWkR-wtM)
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/news/linus-torvalds-talks-iot-smart-devices-security-concerns-and-more-video
|
||||
|
||||
作者：[ERIC BROWN][a]
|
||||
译者：[vim-kakali](https://github.com/vim-kakali)
|
||||
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/users/ericstephenbrown
|
||||
[0]: http://events.linuxfoundation.org/events/embedded-linux-conference
|
||||
[1]: http://go.linuxfoundation.org/elc-openiot-summit-2016-videos?utm_source=lf&utm_medium=blog&utm_campaign=linuxcom
|
||||
|
||||
58
translated/talk/20160531 The Anatomy of a Linux User.md
Normal file
58
translated/talk/20160531 The Anatomy of a Linux User.md
Normal file
@ -0,0 +1,58 @@
|
||||
|
||||
|
||||
一个 Linux 用户的故事
|
||||
================================
|
||||
|
||||
|
||||
|
||||
**一些新的 GNU/Linux 用户都很清楚的知道 Linux 不是 Windows .其他很多人都不是很清楚的知道．最好的发行版设计者努力保持新的思想**
|
||||
|
||||
### Linux 的核心
|
||||
|
||||
不管怎么说，Ｎicky 都不是那种表面上看起来很值得注意的人．她已经三十岁了，却决定回到学校学习．她在海军待了６年时间直到她的老友给她一份新的工作，而且这份工作比她在军队的工作还好．在过去的军事分支服务期间发生了很多事情．我认识她还是她在军队工作的时候．她是８个州的货车运输业协商区域的管理者．那会我在达拉斯跑肉品包装工具的运输．
|
||||
|
||||
|
||||
|
||||
Nicky 和我在 2006 年成为了好朋友．她很外向，并且有很强的好奇心，她几乎走过每个运输商走的路线．一个星期五晚上我们在灯光下有一场很激烈的争论，像这样的 达 30 分钟的争论在我们之间并不少见．或许这并不比油漆一个球场省事，但是气氛还是可以控制的住的，感觉就像是一个很恐怖的游戏．在这次争论的时候她问到我是否可以修复她的电脑．
|
||||
|
||||
她知道我为了一些贫穷的孩子能拥有他们自己的电脑做出的努力，当她抱怨她的电脑很慢的时候，我提到了参加 Bill Gate 的 401k 计划［译注:这个计划是为那些为内部收益代码做过贡献的人们提供由税收定义的养老金账户．］．Nicky 说这是了解 Linux 的最佳时间．
|
||||
|
||||
她的电脑相当好，它是一个带有 Dell 19 显示器的华硕电脑．不好的是，当不需要一些东西的时候，这个 Windows 电脑会强制性的显示所有的工具条和文本菜单．我们把电脑上的文件都做了备份之后就开始安装 Linux 了．我们一起完成了安装，并且我确信她知道了如何分区．不到一个小时，她的电脑上就有了一个漂亮的 PCLinuxOS 桌面．
|
||||
|
||||
她会经常谈论她使用新系统的方法，系统看起来多么漂亮．她不曾提及的是，她几乎被她面前的井然有序的漂亮桌面吸引．她说她的桌面带有漂亮的"微光"．这是我在安装系统期间特意设置的．我每次在安装 Linux 的时候都会进行这样的配置．我想让每个 Linux 用户的桌面都配置这个漂亮的微光．
|
||||
|
||||
大概第一周左右，她给我打电话或者发邮件问了一些常规的问题，但是最主要的问题还是她想知道怎样保存她打开的 Office 文件（OpenOffice）以至于她的同事也可以读这些文件．教一个人使用 Linux 或者 Open/LibreOffice 的时候最重要的就是教她保存文件．大多数用户仅仅看到第一个提示，只需要手指轻轻一点就可以以打开文件模式( Open Document Format )保存．
|
||||
|
||||
|
||||
大约一年前或者更久，一个高中生说他没有通过期末考试，因为教授不能打开他写着论文的文件．这引来不能决定谁对谁错的读者的激烈评论．这个高中生和教授都不知道这件事该怪谁．
|
||||
|
||||
我知道一些大学教授甚至每个人都能够打开一个 ODF 文件．见鬼，很少有像微软这样优秀的公司，我想 Microsoft Office 现在已经能打开 ODT 或者 ODF 文件了．我也不能确保，毕竟我最近一次用 Microsoft Office 是在 2005 年．
|
||||
|
||||
甚至在困难时期,当 Microsoft 很受欢迎并且很热衷于为使用他们系统的厂商的企业桌面上安装他们自己的软件的时候，我和一些使用 Microsoft Office 的用户的产品生意和合作从来没有出现过问题，因为我会提前想到可能出现的问题并且不会有侥幸心理．我会发邮件给他们询问他们正在使用的 Office 版本．这样，我就可以确保以他们能够读写的格式保存文件．
|
||||
|
||||
说到 Nicky ，她花了很多时间学习她的 Linux 系统．我很惊奇于她的热情．
|
||||
|
||||
当人们意识到所有的使用 Windows 的习惯和工具都要被抛弃的时候，学习 Linux 系统也会很容易．甚至在我们谈论第一次用的系统时，我查看这些系统的桌面或者下载文件夹大多都找不到 some_dodgy_file.exe 这样的文件．
|
||||
|
||||
在我们通常讨论这些文件的时候，我们也会提及关于更新的问题．很长时间我都不会在一台电脑上反复设置去完成多种程序的更新和安装．比如 Mint ，它没有带有 Synaptic ［译注:一个 Linux 管理图像程序包］的完整更新方法,这让我失去兴趣．但是我们的老成员 dpkg 和 apt 是我们的好朋友，聪明的领导者已经得到肯定并且认识到命令行看起来不是那么舒服，同时欢迎新的用户加入．
|
||||
|
||||
我很生气，强烈反对机器对 Synaptic 的削弱，最后我放弃使用它．你记得你第一次使用的 Linux 发行版吗？记得你什么时候在 Synaptic 中详细查看大量的软件列表吗？记得你怎样开始检查并标记每个你发现的很酷的程序吗？你记得有多少这样的程序开始都是使用"lib"这样的文件吗？
|
||||
|
||||
是的，我也是。我安装并且查看了一些新的安装程序，直到我发现那些库文件是应用程序的螺母和螺栓，而不是应用程序本身．这就是为什么这些聪明的开发者在 Linux Mint 和 Ubuntu 之后创造了聪明、漂亮和易于使用的应用程序的安装程序．Synaptic 仍然是我们的老大，但是对于一些后来者，安装像 lib 文件这样的方式需要打开大量的文件夹，很多这样的事情都会导致他们放弃使用这个系统．在新的安装程序中，这些文件会被放在一个文件夹中甚至不会展示给用户．总之，这也是该有的解决方法．
|
||||
|
||||
除非你要改变应该支持的需求．
|
||||
|
||||
现在的 Linux 发行版中有很多有用的软件，我也很感谢这些开发者，因为他们，我的工作变得容易．不是每一个 Linux 新用户都像 Nicky 这样富有热情．她相当不错的完成了安装过程并且达到了忘我的状态．像她这样极具热情的毕竟是少数．大多数新的 Linux 用户也就是在需要的时候才这样用心．
|
||||
|
||||
很不错，他们都是要教自己的孩子使用 Linux 的人．
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://fossforce.com/2016/05/anatomy-linux-user/
|
||||
|
||||
作者：[Ken Starks][a]
|
||||
译者：[vim-kakali](https://github.com/vim-kakali)
|
||||
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]: http://linuxlock.blogspot.com/
|
||||
@ -0,0 +1,121 @@
|
||||
|
||||
|
||||
Ubuntu Snap 软件包管理 Linux 桌面和 IoT 的软件安装
|
||||
===========================================================================
|
||||
|
||||
|
||||
[Canonical][28] 和 [Ubuntu][29] 创始人 Mark Shuttleworth 在一次采访中说他不计划宣布 Ubuntu 的新 [ Snap 程序包格式][30]。但是
|
||||
在之后几个月，各种 Linux 发行版的开发者和团队都宣布他们会把 Snap 作为通用 Linux 程序包格式。
|
||||
|
||||
>Linux 供应商，独立软件开发商（ISV:Independent Software Vendor）和开发团队都采用 Ubuntu Snap 作为多种 Linux 系统的配置和更新程序包。
|
||||
|
||||
为什么呢？因为 Snap 能使一个二进制程序包可以完美、安全地在任何 Linux 台式机、服务器、云或设备上运行。Canonical 的 Ubuntu 客户端产品和版本负责人 Olli Ries 说：
|
||||
|
||||
|
||||
>[ Snap 程序包的安全机制][1] 允许我们为 Snap 应用单独空出一些系统空间，这样我们就可以根据我们自身的情况更高效的进行循环开发。用户安装一个 Snap 的时候也不用担心是否会影响其他的应用程序和操作系统。
|
||||
|
||||
|
||||
当然了，早期的 Linux 内核开发者和 CoreOS 【译注：CoreOS是一种操作系统，于2013年十二月发布，它的设计旨在关注开源操作系统内核的新兴使用——用于大量基于云计算的虚拟服务器。】安全维护者 Matthew Garrett 指出：如果你 [使用带有不安全程序的 Snap 程序包比如 X11 ][2] 视窗系统【译注：X11也叫做 X Window 系统，X Window 系统 ( X11 或 X )是一种位图显示的视窗系统 。它是在 Unix 和类 Unix 操作系统 ，以及 OpenVMS 上建立图形用户界面的标准工具包和协议，并可用于几乎所有已有的现代操作系统。】，实际上你的系统一点也不安全。
|
||||
|
||||
|
||||
Shuttleworth 同意 Garrett 的观点，但是他也说你可以控制 Snap 应用使用多少的系统剩余空间。比如，一个 web 浏览器可以包含一个安全的 Snap 程序包，这个 Snap 使用 Ubuntu 的一个包 [openssl][3]【译注：OpenSSL 是一个强大的安全套接字层密码库，囊括主要的密码算法、常用的密钥和证书封装管理功能及 SSL 协议，并提供丰富的应用程序供测试或其它目的使用。】的安全传输层(TLS,Transport Layer Security)和安全套接字层(SSL,Secure Sockets Layer)二进制文件。除此之外，即使有程序攻破了浏览器的诉讼程序【译注：诉讼程序属于程序性法律程序中的公力救济型程序】，也不能进行底层的系统操作。
|
||||
|
||||
很多团队也这样认为。[戴尔][4]，[三星][5]，[Mozilla][6],[krita][7]【译注：Krita 是一个位图形编辑软件，KOffice 套装的一部份。包含一个绘画程式和照片编辑器，Krita 是自由软件，并根据GNU通用公共许可证发布。】，[麦考夫][8]【译注：Mycroft 是一个开源AI智能家居平台，配置 Raspberry Pi 2 和 Arduino 控制器，应该就是以夏洛克福尔摩斯的哥哥为名的。】，以及 [地平线计算][9] 【译注：地平线计算解决方案，为客户提供优质的硬件架构为其运行云平台。】都将使用 Snap。[Arch Linux][10],[Debain][11]，[Gentoo][12]，和 [OpenWrt][13] 【译注：OpenWrt 可以被描述为一个嵌入式的 Linux 发行版】开发团队也已经拥抱了 Snap，也会把 Snap 加入到他们各自开发的分支中。
|
||||
|
||||
Snap 包又叫做“ Snaps ”，现在在 Arch、Debian、Fedora、Kubuntu、Lubuntu、Ubuntu GNOME、Ubuntu Kylin、Ubuntu MATE、Ubuntu Unity 和 Xubuntu 上运行。 Snap 正在 CentOS、Elementary、Gentoo、Mint、OpenSUSE 和 Red Hat Enterprise Linux (RHEL) 上予以验证，并且在其他 Linux 发行版上运行也会很容易。
|
||||
|
||||
这些发行版都使用 Snaps，Shuttleworth 声称：“ Snaps 为每个 Linux 台式机、服务器、设备和云机器带来了很多应用程序，也给了用户更大的自由，用户可以选择任何带有最好应用程序的 Linux 发行版本。”
|
||||
|
||||
把这些发行版放在一起代表了大多的主流 Linux 桌面、服务器和云系统分支。为什么他们切换到本地包来进行系统管理呢？ Arch Linux 的贡献者
|
||||
除过这些 Linux 分支，独立软件开发商（ISV,Independent Software Vendor）也将会因为 Snap 很好的简化了第三方 Linux 应用程序和安全维护问题而拥抱 Snap。例如，[文档基金会][14] 也将会开发出受欢迎的可用开源 office 套件 [LibreOffice][15] 作为一个 Snap 程序包。
|
||||
|
||||
文档基金会的联合创始人 Thorsten Behrens 这样说：
|
||||
|
||||
>我们的目标是使 LibreOffice 能被大多数人更容易使用成为可能。Snap 使我们的用户能够在不同的桌面系统和分支上更快捷更容易的持续获取最新的 LibreOffice 版本。如上所述，它也会帮助我们的版本开发工程师最终从定期的自产的陈旧 Linux 开发解决方案中解放出来，总之很多东西会被共同维护。
|
||||
|
||||
Ｍozilla 的 [火狐][16] 副总裁（VP,Vice President）Nick Nguyen 在这段陈述中提到：
|
||||
|
||||
>我们力求为用户提供良好的使用体验，并且使火狐浏览器能够在更多平台、设备和操作系统上运行。随着对 Snaps 的介绍，我们也会对火狐浏览器进行持续优化，使它可以为 Linux 用户提供最新特性。
|
||||
|
||||
基于 KDE 的图形程序的 [Krita Foundation][17] 项目领导 Boudewijn Rempt 说：
|
||||
|
||||
|
||||
>正在维护的 DEB 包在一个私有仓库，这很复杂也很耗费时间。Snaps 更容易维护、打包和配置。把 Snap 放进软件商店也特别容易，我已经把软件发布在最合适的软件商店了。[Krita 3.0][18] 刚刚作为一个 snap 程序包发行，它作为最新的版本能够自动更新。
|
||||
|
||||
不仅 Linux 桌面系统程序使用 Snap。物联网(IoT)和嵌入式开发者也双手拥抱了 Snap。
|
||||
|
||||
|
||||
Snaps 彼此隔离开来，以确保安全性，它们还可以自动更新或回滚，这对于硬件设备是极好的。多种厂商都在他们的物联网设备上运行着 snappy【译注：Snap 基于 snappy进行构建。】，能够生产带有物联网应用程序商店的新的“智能边缘”设备。Snappy 设备能够自动接收系统更新，并且连同安装在设备上的应用程序也会得到更新。
|
||||
|
||||
戴尔公司根据最早的物联网厂商之一的创始人 Shuttleworth 看到的 Snap 的巨大潜力决定在他们的设备上使用 Snap。
|
||||
|
||||
戴尔公司的物联网战略和合作伙伴主管 Jason Shepherd 说：“我们认为，Snaps 能够报告安全风险，也能解决在单一物联网网关上部署和运行多个第三方应用程序所带来的安全风险和可管理性挑战。这种课信赖的通用的应用程序格式才是戴尔真正需要的，我们的物联网解决方案合作伙伴和产品客户都对物联网应用程序的充满活力的生态系统有极大的兴趣。”
|
||||
|
||||
|
||||
OpenWrt 的开发者 Matteo Croce 说：“这很简单，在脱离无变化的核心操作系统的时候 Snaps 会为 OpenWrt 递送大量的软件...Snaps 是通过点和路由为 OpenWrt 提供大量软件的最快方式。”
|
||||
|
||||
Shuttleworth 认为 Snaps 不会取代已经存在的 Linux 程序包比如 [RPM][19] 和 [DEB][20]。相反，他认为他们将会相辅相成。Snaps 将会与现有包共存。每个发行版都有为系统内核提供更新的相应机制，这种机制也在不断更新。Snap 为桌面系统带来的是通用的应用程序，这些应用程序不会影响基本的系统操作。
|
||||
|
||||
每个 Snap 使用大量的独立核心和安全机制时也会有所限制，这是 Snap 应用程序的特色，谨慎的重览过程确保 Snap 仅仅得到其完成请求操作的权限。用户在安装 Snap 的时候也不必考虑复杂的安全问题。
|
||||
|
||||
Snap实际上是独立式zip文件，能够非常迅速地在原地执行，很受欢迎的[中标麒麟][21]团队的负责人 Jack Yu 称：“Snaps 比传统的 Linux 包更容易构建，允许我们对这种基本的系统的操作的独立性产生依赖，所以我们可以为所有的分支用户开发更好的最新国产 Linux 应用程序。”
|
||||
|
||||
Snap 程序包格式由 Canonical 设计，基于 [snapd][22] 。这是GitHub上的一个软件项目。大多 Linux 发行版的部分 snapd 已经被证明是容易理解的，社区里也加入了新的有大量 Linux 经验的贡献者。
|
||||
|
||||
|
||||
Snap 程序包使用 snapcraft 工具来构建。项目基地是 [snapcraft.io][24] 网站，附有构建 Snap 的预览和逐步指南，不包括项目开发者和使用者的文件。Snap可能基于现有的发行版程序包，但更常使用源代码来构建，为了优化和规模效率。
|
||||
|
||||
如果你不是 Ubuntu 的忠实粉丝或者一个偏执的 Linux 开发者你可能不知道 Snap。未来，在任何平台上需要用 Linux 完成工作的任何人都会知道这个软件。用它的方法完成工作会成为主流 -- 尤其在这些方面将更重要 -- Linux 应用程序的安装和更新机制。
|
||||
|
||||
|
||||
#### 相关内容：
|
||||
|
||||
|
||||
- [Linux 专家 Matthew Garrett：Ubuntu 16.04 的新 Snap 程序包格式存在安全风险 ][25]
|
||||
- [Ubuntu Linux 16.04 ]
|
||||
- [Microsoft 和 Canonical 合作使 Ubuntu 可以在 Windows 10 上运行 ]
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.zdnet.com/article/ubuntu-snap-takes-charge-of-linux-desktop-and-iot-software-distribution/
|
||||
|
||||
作者：[Steven J. Vaughan-Nichols][a]
|
||||
译者：[vim-kakali](https://github.com/vim-kakali)
|
||||
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]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/
|
||||
[28]: http://www.canonical.com/
|
||||
[29]: http://www.ubuntu.com/
|
||||
[30]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/
|
||||
[1]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/
|
||||
[2]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/
|
||||
[3]: https://www.openssl.org/
|
||||
[4]: http://www.dell.com/en-us/
|
||||
[5]: http://www.samsung.com/us/
|
||||
[6]: http://www.mozilla.com/
|
||||
[7]: https://krita.org/en/
|
||||
[8]: https://mycroft.ai/
|
||||
[9]: http://www.horizon-computing.com/
|
||||
[10]: https://www.archlinux.org/
|
||||
[11]: https://www.debian.org/
|
||||
[12]: https://www.gentoo.org/
|
||||
[13]: https://openwrt.org/
|
||||
[14]: https://www.documentfoundation.org/
|
||||
[15]: https://www.libreoffice.org/download/libreoffice-fresh/
|
||||
[16]: https://www.mozilla.org/en-US/firefox/new/
|
||||
[17]: https://krita.org/en/about/krita-foundation/
|
||||
[18]: https://krita.org/en/item/krita-3-0-released/
|
||||
[19]: http://rpm5.org/
|
||||
[20]: https://www.debian.org/doc/manuals/debian-faq/ch-pkg_basics.en.html
|
||||
[21]: http://www.ubuntu.com/desktop/ubuntu-kylin
|
||||
[22]: https://launchpad.net/ubuntu/+source/snapd
|
||||
[23]: https://github.com/snapcore/snapd
|
||||
[24]: http://snapcraft.io/
|
||||
[25]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/
|
||||
[26]: http://www.zdnet.com/article/ubuntu-linux-16-04-is-here/
|
||||
[27]: http://www.zdnet.com/article/microsoft-and-canonical-partner-to-bring-ubuntu-to-windows-10/
|
||||
|
||||
|
||||
@ -0,0 +1,59 @@
|
||||
Training vs. hiring to meet the IT needs of today and tomorrow
|
||||
培训还是雇人，来满足当今和未来的 IT 需求
|
||||
================================================================
|
||||
|
||||
|
||||
|
||||
在数字化时代，由于企业需要不断跟上工具和技术更新换代的步伐，对 IT 技能的需求也稳定增长。对于企业来说，寻找和雇佣那些拥有令人垂涎能力的创新人才，是非常不容易的。同时，培训内部员工来使他们接受新的技能和挑战，需要一定的时间。而且，这也往往满足不了需求。
|
||||
|
||||
[Sandy Hill][1] 对多种 IT 学科涉及到的多项技术都很熟悉。她作为 [Pegasystems][2] 项目的 IT 主管，负责的 IT 团队涉及的领域从应用的部署到数据中心的运营。更重要的是，Pegasystems 开发应用来帮助销售，市场，服务以及运行团队简化操作，联系客户。这意味着她需要掌握和利用 IT 内部资源的最佳方法，面对公司客户遇到的 IT 挑战。
|
||||
|
||||
|
||||
|
||||
**企业家项目（TEP）：这些年你是如何调整培训重心的？**
|
||||
|
||||
**Hill**：在过去的几十年中，我们经历了爆炸式的发展，所以现在我们要实现更多的全球化进程。随之而来的培训方面，将确保每个人都在同一起跑线上。
|
||||
|
||||
我们大多的关注点已经转移到培养员工使用新的产品和工具上，这些新产品和工具的实现，能够推动创新，并提高工作效率。例如，我们实现了资产管理系统; 以前我们是没有的。因此我们需要为全部员工做培训，而不是雇佣那些已经知道该产品的人。当我们正在发展的时候，我们也试图保持紧张的预算和稳定的职员总数。所以，我们更愿意在内部培训而不是雇佣新人。
|
||||
|
||||
**TEP：说说培训方法吧，你是怎样帮助你的员工发展他们的技能？**
|
||||
|
||||
**Hill**：我要求每一位员工制定一个技术性的和非技术性的训练目标。这作为他们绩效评估的一部分。他们的技术性目标需要与他们的工作职能相符，非技术行目标则着重发展一项软技能，或是学一些专业领域之外的东西。我每年对职员进行一次评估，看看差距和不足之处，以使团队保持全面发展。
|
||||
|
||||
**TEP：你的训练计划能够在多大程度上减轻招聘和保留职员的问题？**
|
||||
|
||||
**Hill**：使我们的职员对学习新的技术保持兴奋，让他们的技能更好。让职员知道我们重视他们并且让他们在擅长的领域成长和发展，以此激励他们。
|
||||
|
||||
**TEP：你有没有发现哪种培训是最有效的？**
|
||||
|
||||
**HILL**：我们使用几种不同的我们发现是有效的培训方法。当有新的或特殊的项目时，我们尝试加入一套由甲方（不会翻：乙方，卖方？）领导的培训课程，作为项目的一部分。要是这个方法不能实现，我们将进行异地培训。我们也会购买一些在线的培训课程。我也鼓励职员每年参加至少一次会议，以了解行业的动向。
|
||||
|
||||
**TEP：你有没有发现有哪些技能，雇佣新人要比培训现有员工要好？**
|
||||
|
||||
**Hill**：这和项目有关。有一个最近的计划，试图实现 OpenStack，而我们根本没有这方面的专家。所以我们与一家从事这一领域的咨询公司合作。我们利用他们的专业知识帮助我们运行项目，并现场培训我们的内部团队成员。让内部员工学习他们需要的技能，同时还要完成他们们天的工作，这是一项艰巨的任务。
|
||||
|
||||
顾问帮助我们确定我们需要的对某一技术熟练的的员工人数。这使我们能够对员工进行评估，看看是否存在缺口。如果存在人员上的缺口，我们还需要额外的培训或是员工招聘。我们也确实雇佣了一些承包商。另一个选择是让一些全职员工进行为期六至八周的培训，但我们的项目模式不容许这么做。
|
||||
|
||||
**TEP：想一下你最近雇佣的员工，他们的那些技能特别能够吸引到你？**
|
||||
|
||||
**Hill**：在最近的招聘中，我侧重于软技能。除了扎实的技术能力外，他们需要能够在团队中进行有效的沟通和工作，要有说服他人，谈判和解决冲突的能力。
|
||||
|
||||
IT 人一向独来独往。他们一般不是社交最多的人。现在，IT 越来越整合到组织中，它为其他业务部门提供有用的更新报告和状态报告的能力是至关重要的，这也表明 IT 是积极的存在，并将取得成功。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://enterprisersproject.com/article/2016/6/training-vs-hiring-meet-it-needs-today-and-tomorrow
|
||||
|
||||
作者：[Paul Desmond][a]
|
||||
译者：[Cathon](https://github.com/Cathon)
|
||||
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://enterprisersproject.com/user/paul-desmond
|
||||
[1]: https://enterprisersproject.com/user/sandy-hill
|
||||
[2]: https://www.pega.com/pega-can?&utm_source=google&utm_medium=cpc&utm_campaign=900.US.Evaluate&utm_term=pegasystems&gloc=9009726&utm_content=smAXuLA4U|pcrid|102822102849|pkw|pegasystems|pmt|e|pdv|c|
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,62 +0,0 @@
|
||||
信息技术运行在云端，而云运行在 Linux 上。有什么问题吗？
|
||||
===================================================================
|
||||
|
||||
>信息技术正在逐渐被迁移到云端. 那又是什么驱动了云呢？答案是 Linux。 当连微软的 Azure 都开始拥抱 Linux 时，你就应该知道这一切都已经改变了。
|
||||
|
||||
|
||||
>图片： ZDNet
|
||||
|
||||
不管你接不接受， 云正在接管信息技术都已成现实。 我们这几年见证了 [ 云在信息技术产业内部的崛起 ][1] 。 那又是什么驱动了云呢？ 答案是 Linux 。
|
||||
|
||||
[Uptime Institute][2] 最近对 1000 个 IT 执行部门进行调查并发现了约 50% 左右的高级企业的 IT 执行部门认为在将来 [ 大部分的 IT 工作内容应存储备份在云上 ][3] 或托管网站上。在这个调查中，23% 的人认为这种改变即将发生在明年，有 70% 的人则认为这种情况会在四年内出现。
|
||||
|
||||
这一点都不奇怪。 我们中的许多人仍热衷于我们的物理服务器和机架， 但一般运营一个自己的数据中心并不会产生任何的经济效益。
|
||||
|
||||
这真的非常简单。 只需要对比你 [ 运行在硬件上的个人资本费用 (CAPEX) 和使用云的操作费用 (OPEX)][4]。 但这并不是说你会想把所有的一切都外置，而是说在大部分时间内你会想把你的一些工作内容迁移到云端。
|
||||
|
||||
相应地，如果你想充分地利用云，你就得了解 Linux 。
|
||||
|
||||
[ 亚马逊 web 服务 ][5]， [ Apache 的 CloudStack][6]， [Rackspace][7]， [ 谷歌云平台 ][8] 以及 [ OpenStack ][9] 的核心都是运行在 Linux 上的。那么结果如何？截至到 2014 年， [ 在 Linux 服务器上部署的应用达到所有企业的 79% ][10]，而 Windows 服务器上部署的应用则跌到 36%。从那时起， Linux 就获得了更多的发展动力。
|
||||
|
||||
即便是微软自身也明白这一点。
|
||||
|
||||
Azure 的技术主管 Mark Russinovich 曾说，仅仅在过去的几年内微软就从 [ 四分之一的 Azure 虚拟机运行在 Linux 上 ][11] 变为 [ 将近三分之一的 Azure 虚拟机运行在 Linux 上][12].
|
||||
|
||||
试想一下。 微软， 一家正逐渐将 [ 云变为自身财政收入的主要来源 ][13] 的公司，其三分之一的云产业依靠于 Linux 。
|
||||
|
||||
即使是到目前为止， 这些不论喜欢或者不喜欢微软的人都很难想象得到 [ 微软会从一家以专利保护为基础的软件公司转变为一家开源，基于云服务的企业][14] 。
|
||||
|
||||
Linux 对于这些专用服务器机房的渗透甚至比它刚开始的时候更深了。 举个例子， [ Docker 最近发行了其在 Windows 10 和 Mac OS X 上的公测版本 ][15] 。 所以难道这意味着 [Docker][16] 将会把其同名的容器服务移植到 Windows 10 和 Mac 上吗？ 并不是的。
|
||||
|
||||
在这两个平台上， Docker 只是运行在一个 Linux 虚拟机内部。 在 Mac OS 上是 HyperKit ，在 Windows 上则是 Hyper-V 。 你的图形界面可能看起来就像另一个 Mac 或 Windows 上的应用， 但在其内部核心的容器仍然是运行在 Linux 上的。
|
||||
|
||||
所以，就像大量的安卓手机和 Chromebook 的用户压根就不知道他们所运行的是 Linux 系统一样。这些信息技术的用户也会随之悄然地迁移到 Linux 和云上。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.zdnet.com/article/it-runs-on-the-cloud-and-the-cloud-runs-on-linux-any-questions/#ftag=RSSbaffb68
|
||||
|
||||
作者：[Steven J. Vaughan-Nichols][a]
|
||||
译者：[chenxinlong](https://github.com/chenxinlong)
|
||||
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]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/
|
||||
[1]: http://www.zdnet.com/article/2014-the-year-the-cloud-killed-the-datacenter/
|
||||
[2]: https://uptimeinstitute.com/
|
||||
[3]: http://www.zdnet.com/article/move-to-cloud-accelerating-faster-than-thought-survey-finds/
|
||||
[4]: http://www.zdnet.com/article/rethinking-capex-and-opex-in-a-cloud-centric-world/
|
||||
[5]: https://aws.amazon.com/
|
||||
[6]: https://cloudstack.apache.org/
|
||||
[7]: https://www.rackspace.com/en-us
|
||||
[8]: https://cloud.google.com/
|
||||
[9]: http://www.openstack.org/
|
||||
[10]: http://www.zdnet.com/article/linux-foundation-finds-enterprise-linux-growing-at-windows-expense/
|
||||
[11]: http://news.microsoft.com/bythenumbers/azure-virtual
|
||||
[12]: http://www.zdnet.com/article/microsoft-nearly-one-in-three-azure-virtual-machines-now-are-running-linux/
|
||||
[13]: http://www.zdnet.com/article/microsofts-q3-azure-commercial-cloud-strong-but-earnings-revenue-light/
|
||||
[14]: http://www.zdnet.com/article/why-microsoft-is-turning-into-an-open-source-company/
|
||||
[15]: http://www.zdnet.com/article/new-docker-betas-for-azure-windows-10-now-available/
|
||||
[16]: http://www.docker.com/
|
||||
|
||||
71
translated/talk/20160627 Linux Practicality vs Activism.md
Normal file
71
translated/talk/20160627 Linux Practicality vs Activism.md
Normal file
@ -0,0 +1,71 @@
|
||||
Linux 的实用性 VS 行动主义
|
||||
==================================
|
||||
|
||||
>我们使用 Linux 是因为它比其他操作系统更实用，还是其他更高级的理由呢？
|
||||
|
||||
其中一件关于运行 Linux 的最伟大的事情之一就是它所提供的自由。凡出现在 Linux 社区之间的划分在于我们如何珍惜这种自由。
|
||||
|
||||
一些人认为，通过使用 Linux 所享有的自由是从供应商锁定或高软件成本的自由。大多数人会称这个是一个实际的考虑。而其他用户会告诉你，他们享受的是自由软件的自由。那就意味着拥抱支持 [开源软件运动][1] 的 Linux 发行版，完全避免专有软件和所有相关的东西。
|
||||
|
||||
|
||||
在这篇文章中，我将带你比较这两种自由的区别，以及他们如何影响 Linux 的使用。
|
||||
|
||||
### 专有的问题
|
||||
|
||||
大多数的用户有一个共同的一点是他们的喜欢避免专有软件。对于像我这样的实际的爱好者来说，这是一个我怎么样花我的钱，来控制我的软件和避免供应商锁定的问题。当然，我不是一个程序员……所以我调整我的安装软件是十分温柔的。但也有一些个别情况，一个应用程序的小调整可以意味着它的工作和不工作的区别。
|
||||
|
||||
还有就是选择避开专有软件的Linux爱好者，因为他们觉得这是不道德的使用。通常这里主要的问题是使用专有软件会带走或者干脆阻碍你的个人自由。像这些用户更喜欢使用的Linux发行版和软件来支持 [自由软件理念][2] 。虽然它类似于开源的概念并经常直接与之混淆，[这里有些差异][3] 。
|
||||
|
||||
因此，这里有个问题：像我这样的用户往往以其便利掩盖了其纯软件自由的理想化。不要误会我的意思，像我这样的人更喜欢使用符合自由软件背后的理想软件，但我们也更有可能做出让步，以完成特定的任务。
|
||||
|
||||
这两种类型的 Linux 爱好者都喜欢使用非专有的解决方案。但是，自由软件倡导者根本不会去使用所有权，在那里作为实际的用户将依靠具有最佳性能的最佳工具。这意味着，在有些情况下的实际用户愿意来运行他们的非专有操作系统上的专有应用或代码实例。
|
||||
|
||||
最终，这两种类型的用户都喜欢使用 Linux 所提供的。但是，我们这样做的原因往往会有所不同。有人认为那些不支持自由软件的人是无知的。我不同意，我认为它是实用方便性的问题。那些喜欢实用方便性的用户根本不关心他们软件的政治问题。
|
||||
|
||||
### 实用方便性
|
||||
|
||||
当你问起绝大多数的人为什么使用他们现在的操作系统，回答通常都集中于实用方便性。这种关于方便性的例子可能包括“它是我一直使用的东西”、“它运行的软件是我需要的”。 其他人可能进一步解释说，并没有那么多软件影响他们对操作系统的偏好和熟悉程度，最后，有“利基任务”或硬件兼容性问题也提供了很好的理由让我们用这个操作系统而不是另一个。
|
||||
|
||||
这可能会让你们中许多人很惊讶，但我今天运行的桌面 Linux 最大的一个原因是由于熟悉。即使我为别人提供对 Windows 和 OS X 的支持，但实际上我是相当沮丧地使用这些操作系统，因为它们根本就不是我记忆中的那样习惯用法。我相信这可以让我对那些 Linux 新手表示同情，因为我太懂得踏入陌生的领域是怎样的让人倒胃口了。我的观点是这样的 —— 熟悉具有价值。而且熟悉同样使得实用方便性变得有力量。
|
||||
|
||||
现在，如果我们把它和一个自由软件倡导者的需求来比较，你会发现那些人都愿意学习新的东西，甚至更具挑战性，去学习那些若转化成为他们所避免使用的非自由软件。这就是我经常赞美的那种用户，我认为他们愿意采取最少路径来遵循坚持他们的原则是十分值得赞赏的。
|
||||
|
||||
### 自由的价值
|
||||
|
||||
我不羡慕那些自由软件倡导者的一个地方，就是根据 [自由软件基金会][4] 所规定的标准需要确保他们可以一直使用 Linux 发行版和硬件，以便于尊重他们的数字自由。这意味着 Linux 内核需要摆脱专有的斑点的驱动支持和不需要任何专有代码的硬件。当然不是不可能的，但它很接近。
|
||||
|
||||
一个自由软件倡导者可以达到的最好的情况是硬件是“自由兼容”的。有些供应商，可以满足这一需求，但他们大多是提供依赖于 Linux 兼容专有固件的硬件。伟大的实际用户对自由软件倡导者来说是个搅局者。
|
||||
|
||||
那么这一切意味着的是，倡导者必须比实际的 Linux 爱好者，更加警惕。这本身并不一定是消极的，但如果是打算用自由软件的方法来计算的话那就值得考虑了。通过对比，实用的用户可以专心地使用与 Linux 兼容的任何软件或硬件。我不知道你是怎么想的，但在我眼中是更轻松一点的。
|
||||
|
||||
### 定义自由软件
|
||||
|
||||
这一部分可能会让一部分人失望，因为我不相信自由软件只有一种。从我的立场，我认为真正的自由是能够在一个给定的情况里沉浸在所有可用的数据里，然后用最适合这个人的生活方式的途径来达成协议。
|
||||
|
||||
所以对我来说，我更喜欢使用的 Linux 桌面，满足了我所有的需求，这包括使用非专有软件和专有软件。尽管这是公平的建议，专有的软件限制了我的个人自由，但我必须反驳这一点，因为我有选择用不用它，即选择的自由。
|
||||
|
||||
或许，这也就是为什么我发现自己更确定开源软件的理想，而不是坚持自由软件运动背后的理念的原因。我更愿意和那些不会花时间告诉我，我是怎么用错了的那些人群在一起。我的经验是，那些开源的人群仅仅是感兴趣去分享自由软件的优点，而不是因为自由软件的理想主义的激情。
|
||||
|
||||
我觉的自由软件的概念实在是太棒了。对那些需要活跃在软件政治，并指出使用专有软件的人的缺陷的人来说，那么我认为 Linux ( [GNU/Linux][5] ) 行动是一个不错的选择。在我们的介绍里，像我一样的实际用户更倾向于从自由软件的支持者改变方向。
|
||||
|
||||
当我介绍 Linux 的桌面时，我富有激情地分享它的实际优点。而且我成功地让他们享受这一经历，我允许用户自己去发现自由软件的观点。但我发现大多数人使用的 Linux 不是因为他们想拥抱自由软件，而是因为他们只是想要最好的用户体验。也许只有我是这样的，很难说。
|
||||
|
||||
嘿！说你呢？你是一个自由软件倡导者吗？也许你是个使用桌面 Linux 发行专有软件/代码的粉丝？那么评论和分享您的 Linux 桌面体验吧！
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.datamation.com/open-source/linux-practicality-vs-activism.html
|
||||
|
||||
作者：[Matt Hartley][a]
|
||||
译者：[joVoV](https://github.com/joVoV)
|
||||
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]: http://www.datamation.com/author/Matt-Hartley-3080.html
|
||||
[1]: https://en.wikipedia.org/wiki/Free_software_movement
|
||||
[2]: https://www.gnu.org/philosophy/free-sw.en.html
|
||||
[3]: https://www.gnu.org/philosophy/free-software-for-freedom.en.html
|
||||
[4]: https://en.wikipedia.org/wiki/Free_Software_Foundation
|
||||
[5]: https://en.wikipedia.org/wiki/GNU/Linux_naming_controversy
|
||||
@ -0,0 +1,109 @@
|
||||
Translating by ivo-wang
|
||||
What is good stock portfolio management software on Linux
|
||||
linux上那些不错的管理股票组合投资软件
|
||||
================================================================================
|
||||
如果你在股票市场做投资，那么你可能非常清楚管理组合投资的计划有多重要。管理组合投资的目标是依据你能承受的风险，时间层面的长短和资金盈利的目标去为你量身打造的一种投资计划。鉴于这类软件的重要性，难怪从不缺乏商业性质的app和股票行情检测软件，每一个都可以兜售复杂的组合投资以及跟踪报告功能。
|
||||
|
||||
对于这些linux爱好者们，我们找到了一些 **好用的开源组合投资管理工具** 用来在linux上管理和跟踪股票的组合投资，这里高度推荐一个基于java编写的管理软件[JStock][1]。如果你不是一个java粉，你不得不面对这样一个事实JStock需要运行在重型的JVM环境上。同时我相信许多人非常欣赏JStock，安装JRE以后它可以非常迅速的安装在各个linux平台上。没有障碍能阻止你将它安装在你的linux环境中。
|
||||
|
||||
开源就意味着免费或标准低下的时代已经过去了。鉴于JStock只是一个个人完成的产物，作为一个组合投资管理软件它最令人印象深刻的是包含了非常多实用的功能，以上所有的荣誉属于它的作者Yan Cheng Cheok!例如，JStock 支持通过监视列表去监控价格，多种组合投资，按习惯/按固定 做股票指示与相关扫描，支持27个不同的股票市场和交易平台云端备份/还原。JStock支持多平台部署(Linux, OS X, Android 和 Windows)，你可以通过云端保存你的JStock记录，它可以无缝的备份还原到其他的不同平台上面。
|
||||
|
||||
现在我将向你展示如何安装以及使用过程的一些具体细节。
|
||||
|
||||
### 在Linux上安装JStock ###
|
||||
|
||||
因为JStock使用Java编写，所以必须[安装 JRE][2]才能让它运行起来.小提示JStock 需要JRE1.7或更高版本。如你的JRE版本不能满足这个需求，JStock将会安装失败然后出现下面的报错。
|
||||
|
||||
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/yccheok/jstock/gui/JStock : Unsupported major.minor version 51.0
|
||||
|
||||
|
||||
一旦你安装了JRE在你的linux上，从官网下载最新的发布的JStock，然后加载启动它。
|
||||
|
||||
$ wget https://github.com/yccheok/jstock/releases/download/release_1-0-7-13/jstock-1.0.7.13-bin.zip
|
||||
$ unzip jstock-1.0.7.13-bin.zip
|
||||
$ cd jstock
|
||||
$ chmod +x jstock.sh
|
||||
$ ./jstock.sh
|
||||
|
||||
教程的其他部分，让我来给大家展示一些JStock的实用功能
|
||||
|
||||
### 监视监控列表股票价格的波动 ###
|
||||
|
||||
使用JStock你可以创建一个或多个监视列表，它可以自动的监视股票价格的波动并给你提供相应的通知。在每一个监视列表里面你可以添加多个感兴趣的股票进去。之后添加你的警戒值在"Fall Below"和"Rise Above"的表格里，分别是在设定最低价格和最高价格。
|
||||
|
||||
|
||||
|
||||
例如你设置了AAPL股票的最低/最高价格分别是$102 和 $115.50，你将在价格低于$102或高于$115.50的任意时间在桌面得到通知。
|
||||
|
||||
你也可以设置邮件通知，之后你将收到一些价格信息的邮件通知。设置邮件通知在栏的"Options"选项。在"Alert"标签，打开"Send message to email(s)"，填入你的Gmail账户。一旦完成Gmail认证步骤，JStock将开始发送邮件通知到你的Gmail账户（也可以设置其他的第三方邮件地址）
|
||||
|
||||
|
||||
### 管理多个组合投资 ###
|
||||
|
||||
JStock能够允许你管理多个组合投资。这个功能对于股票经纪人是非常实用的。你可以为经纪人创建一个投资项去管理你的 买入/卖出/红利 用来了解每一个经纪人的业务情况。你也可以切换不同的组合项目通过选择一个特殊项目在"Portfolio"菜单里面。下面是一张截图用来展示一个意向投资
|
||||
|
||||
|
||||
因为能够设置付给经纪人小费的选项，所以你能付给经纪人任意的小费，印花税以及清空每一比交易的小费。如果你非常懒，你也可以在菜单里面设置自动计算小费和给每一个经纪人固定的小费。在完成交易之后JStock将自动的计算并发送小费。
|
||||
|
||||
|
||||
|
||||
### 显示固定/自选股票提示 ###
|
||||
|
||||
如果你要做一些股票的技术分析，你可能需要不同股票的指数（这里叫做“平均股指”），对于股票的跟踪，JStock提供多个[预设技术指示器][3] 去获得股票上涨/下跌/逆转指数的趋势。下面的列表里面是一些可用的指示。
|
||||
- 异同平均线（MACD）
|
||||
- 相对强弱指数 (RSI)
|
||||
- 货币流通指数 (MFI)
|
||||
- 顺势指标 (CCI)
|
||||
- 十字线
|
||||
- 黄金交叉线, 死亡交叉线
|
||||
- 涨幅/跌幅
|
||||
|
||||
开启预设指示器能需要在JStock中点击"Stock Indicator Editor"标签。之后点击右侧面板中的安装按钮。选择"Install from JStock server"选项，之后安装你想要的指示器。
|
||||
|
||||
|
||||
|
||||
一旦安装了一个或多个指示器，你可以用他们来扫描股票。选择"Stock Indicator Scanner"标签，点击底部的"Scan"按钮，选择需要的指示器。
|
||||
|
||||
|
||||
|
||||
当你选择完需要扫描的股票(例如e.g., NYSE, NASDAQ)以后，JStock将执行扫描，并将捕获的结果通过列表的形式展现在指示器上面。
|
||||
|
||||
|
||||
|
||||
除了预设指示器以外，你也可以使用一个图形化的工具来定义自己的指示器。下面这张图例中展示的是当前价格小于或等于60天平均价格
|
||||
|
||||
|
||||
|
||||
### 云备份还原Linux 和 Android JStock ###
|
||||
|
||||
另一个非常棒的功能是JStock可以支持云备份还原。Jstock也可以把你的组合投资/监视列表备份还原在 Google Drive，这个功能可以实现在不同平台（例如Linux和Android）上无缝穿梭。举个例子，如果你把Android Jstock组合投资的信息保存在Google Drive上，你可以在Linux班级本上还原他们。
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
如果你在从Google Drive还原之后不能看到你的投资信息以及监视列表，请确认你的国家信息与“Country”菜单里面设置的保持一致。
|
||||
|
||||
JStock的安卓免费版可以从[Google Play Store][4]获取到。如果你需要完整的功能（比如云备份，通知，图表等），你需要一次性支付费用升级到高级版。我想高级版肯定有它的价值所在。
|
||||
|
||||
|
||||
|
||||
写在最后，我应该说一下它的作者，Yan Cheng Cheok，他是一个十分活跃的开发者，有bug及时反馈给他。最后多有的荣耀都属于他一个人！！！
|
||||
|
||||
关于JStock这个组合投资跟踪软件你有什么想法呢？
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://xmodulo.com/stock-portfolio-management-software-linux.html
|
||||
|
||||
作者：[Dan Nanni][a]
|
||||
译者：[ivo-wang](https://github.com/ivo-wang)
|
||||
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]:http://xmodulo.com/author/nanni
|
||||
[1]:http://jstock.org/
|
||||
[2]:http://ask.xmodulo.com/install-java-runtime-linux.html
|
||||
[3]:http://jstock.org/ma_indicator.html
|
||||
[4]:https://play.google.com/store/apps/details?id=org.yccheok.jstock.gui
|
||||
@ -1,49 +0,0 @@
|
||||
Cassandra 和 Spark 数据处理入门
|
||||
==============================================================
|
||||
|
||||
|
||||
|
||||
Apache Cassandra 数据库近来引起了很多的兴趣，这主要源于现代云端软件对于可用性及性能方面的要求。
|
||||
|
||||
那么，Apache Cassandra 是什么？它是一种为高可用性及线性可扩展性优化的分布式的联机交易处理 (OLTP) 数据库。当人们想知道 Cassandra 的用途时，可以想想你想要的离客户近的系统。这j最终是我们的用户进行交互的系统。需要保证实时可用的程序：产品目录，IoT，医疗系统，以及移动应用。对这些程序而言，下线时间意味着利润降低甚至导致其他更坏的结果。Netfilix 是这个于2008年开源的项目的早期使用者，他们对此项目的贡献以及带来的成功让这个项目名声大噪。
|
||||
|
||||
Cassandra 于2010年成为了 Apache 软件基金会的顶级项目，在这之后就开始变得流行。现在，只要你有 Cassadra 的相关知识，找工作时就能轻松不少。光是想想一个 NoSQL 语言和开源技术能达到如此企业级 SQL 的高度就觉得这是十分疯狂而又不可思议的。这引出了一个问题。是什么让它如此的流行？
|
||||
|
||||
因为采用了首先在[亚马逊发表的 Dynamo 论文][1]提出的设计，Cassandra 有能力在大规模的硬件及网络故障时保持实时在线。由于采用了点对点模式，在没有单点故障的情况下，我们能幸免于机架故障甚至完全网络分区。我们能在不影响用户体验的前提下处理数据中心故障。一个能考虑到故障的分布式系统才是一个没有后顾之忧的分布式系统，因为老实说，故障是迟早会发生的。有了 Cassandra， 我们可疑直面残酷的生活并将之融入数据库的结构和功能中。
|
||||
|
||||
|
||||
|
||||
我们能猜到你现在在想什么，“但我只有关系数据库相关背景，难道这样的转变不会很困难吗？"这问题的答案介于是和不是之间。使用 Cassandra 建立数据模型对有关系数据库背景的开发者而言是轻车熟路。我们使用表格来建立数据模型，并使用 CQL 或者 Cassandra 查询语言来查询数据库。然而，与 SQL 不同的是，Cassandra 支持更加复杂的数据结构，例如多重和用户自定义类型。举个例子，当要储存对一个小猫照片的点赞数目时，我们可以将整个数据储存在一个包含照片本身的集合之中从而获得更快的顺序查找而不是建立一个独立的表。这样的表述在 CQL 中十分的自然。在我们照片表中，我们需要记录名字，URL以及给此照片点赞过的人。
|
||||
|
||||
|
||||
|
||||
在一个高性能系统中，毫秒对用户体验和客户保留都能产生影响。昂贵的 JOIN 制约了我们通过增加不可预见的网络调用而扩容的能力。当我们将数据反规范化使其能在尽可能少的请求中被获取到时，我们即可从磁盘空间花费的降低中获益并获得可预测的，高性能应用。我们将反规范化同 Cassandra 一同介绍是因为它提供了很有吸引力的的折衷方案。
|
||||
|
||||
很明显，我们不会局限于对于小猫照片的点赞数量。Canssandra 是一款个为并发高写入优化的方案。这使其成为需要时常吞吐数据的大数据应用的理想解决方案。市场上的时序和 IoT 的使用场景正在以稳定的速度在需求和亮相方面增加，我们也在不断探寻优化我们所收集到的数据以求提升我们的技术应用（注：这句翻的非常别扭，求校队）
|
||||
|
||||
|
||||
这就引出了我们的下一步，我们已经提到了如何以一种现代的，性价比高的方式储存数据，但我们应该如何获得更多的马力呢？具体而言，当我们收集到了所需的数据，我们应该怎样处理呢？如何才能有效的分析几百 TB 的数据呢？如何才能在实时的对我们所收集到的信息进行反馈并在几秒而不是几小时的时间利作出决策呢？Apache Spark 将给我们答案。
|
||||
|
||||
|
||||
Spark 是大数据变革中的下一步。 Hadoop 和 MapReduce 都是革命性的产品，他们让大数据界获得了分析所有我们所取得的数据的机会。Spark 对性能的大幅提升及对代码复杂度的大幅降低则将大数据分析提升到了另一个高度。通过 Spark，我们能大批量的处理计算，对流处理进行快速反映，通过机器学习作出决策并理解通过对图的遍历理解复杂的递归关系。这并非只是为你的客户提供与快捷可靠的应用程序连接（Cassandra 已经提供了这样的功能），这更是能一探 Canssandra 所储存的数据并作出更加合理的商业决策同时更好地满足客户需求。
|
||||
|
||||
你可以看看 [Spark-Cassandra Connector][2] (open source) 并动手试试。若想了解更多关于这两种技术的信息，我们强烈推荐名为 [DataStax Academy][3] 的自学课程
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/5/basics-cassandra-and-spark-data-processing
|
||||
|
||||
作者：[Jon Haddad][a],[Dani Traphagen][b]
|
||||
译者：[KevinSJ](https://github.com/KevinSJ)
|
||||
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://twitter.com/rustyrazorblade
|
||||
[b]: https://opensource.com/users/dtrapezoid
|
||||
[1]: http://www.allthingsdistributed.com/files/amazon-dynamo-sosp2007.pdf
|
||||
[2]: https://github.com/datastax/spark-cassandra-connector
|
||||
[3]: https://academy.datastax.com/
|
||||
[4]: http://conferences.oreilly.com/oscon/open-source-us/public/schedule/detail/49162
|
||||
[5]: https://twitter.com/dtrapezoid
|
||||
[6]: https://twitter.com/rustyrazorblade
|
||||
@ -1,65 +0,0 @@
|
||||
分享的未来：整合 Pydio 与 ownCloud
|
||||
=========================================================
|
||||
|
||||
|
||||
>图片来源 :
|
||||
opensource.com
|
||||
|
||||
开源共享生态圈内容纳了许多各异的项目，他们每一个都能提供出自己的解决方案，且每一个都不按套路来。有很多原因导致你选择开源的解决方案，而非 Dropbox、Google Drive、iCloud 或 OneDrive 这些商业的解决方案。这些商业的解决方案虽然能让你不必为如何管理数据担心，但也理所应当的带着种种限制，其中就包含对于原有基础结构的控制和整合不足。
|
||||
|
||||
对于用户而言仍有相当一部分文件分享和同步的替代品可供选择，其中就包括了 Pydio 和 ownCloud。
|
||||
|
||||
### Pydio
|
||||
|
||||
Pydio （Put your data in orbit 把你的数据放上轨道） 项目由一位作曲家 Charles du Jeu 发起，起初他也只是需要一种与乐队成员分享大型音频文件的方法。[Pydio][1] 是一种文件分享与同步的解决方案，综合了多存储后端，设计时还同时考虑了开发者和系统管理员两方面。在世界各地有逾百万的下载量，已被翻译成 27 种语言。
|
||||
|
||||
项目在很开始的时候便开源了，先是在 [SourceForge][2] 上茁壮的成长，现在已在 [GitHub][3] 上安了家.。
|
||||
|
||||
用户界面基于 Google 的 [Material 设计][4]。用户可以使用现有的传统的文件基础结构或是本地部署 Pydio，并通过 web、桌面和移动端应用随时随地地管理自己的东西。对于管理员来说，细粒度的访问权限绝对是配置访问时的利器。
|
||||
|
||||
在 [Pydio 社区][5]，你可以找到许多让你增速的资源。Pydio 网站 [对于如何为 Pydio GitHub 仓库贡献][6] 给出了明确的指导方案。[论坛][7]中也包含了开发者板块和社区。
|
||||
|
||||
### ownCloud
|
||||
|
||||
[ownCloud][8] 在世界各地拥有逾 8 百万的用户，并且开源，支持自托管文件同步，且共享技术。同步客户端支持所有主流平台并支持 WebDAV 通过 web 界面实现。ownCloud 拥有简单的使用界面，强大的管理工具，和大规模的共享及协作功能——以满足用户管理数据时的需求。
|
||||
|
||||
ownCloud 的开放式架构是通过 API 和为应用提供平台来实现可扩展性的。迄今已有逾 300 款应用，功能包括处理像日历、联系人、邮件、音乐、密码、笔记等诸多数据类型。ownCloud 由一个数百位贡献者的国际化的社区开发，安全，并且能做到为小到一个树莓派大到好几百万用户的 PB 级存储集群量身定制。
|
||||
|
||||
### 联合共享 （Federated sharing）
|
||||
|
||||
文件共享开始转向团队合作时代，而标准化为合作提供了坚实的土壤。
|
||||
|
||||
联合共享——一个由 [OpenCloudMesh][9] 项目提供的新开放标准，就是在这个方向迈出的一步。先不说别的，在支持该标准的服务端上，可以像 Pydio 和 ownCloud 那样分享文件和文件夹。
|
||||
|
||||
ownCloud 7 率先引入，这种服务端到服务端的分享方式可以让你挂载远程服务端上共享的文件，实际上就是创建你所有云的云。你可以直接创建共享链接，让用户在其他支持联合云共享的服务端上使用。
|
||||
|
||||
实现这个新的 API 允许存储解决方案之间更深层次的集成，同时保留了原有平台的安全，控制和属性。
|
||||
|
||||
“交换和共享文件是当下和未来不可或缺的东西。”ownCloud 的创始人 Frank Karlitschek 说道：“正因如此，采用联合和分布的方式而非集中的数据孤岛就显得至关重要。[联合共享]的设计初衷便是在保证安全和用户隐私的同时追求分享的无缝、至简之道。”
|
||||
|
||||
### 下一步是什么呢？
|
||||
|
||||
正如 OpenCloudMesh 做的那样，将会通过像 Pydio 和 ownCloud 这样的机构和公司，合作推广这一文件共享的新开放标准。ownCloud 9 已经引入联合服务端间交换用户列表的功能，让你的用户在你的服务器上享有和你同样的无缝体验。将来，一个中央地址簿服务(联合!)集合，用以检索其他联合云 ID 的想法可能会把云间合作推向一个新的高度。
|
||||
|
||||
这一举措无疑有助于日益开放的技术社区中的那些成员方便地讨论，开发，并推动“OCM 分享 API”作为一个厂商中立协议。所有领导 OCM 项目的合作伙伴都全心致力于开放 API 的设计原理，并欢迎其他开源的文件分享和同步社区参与并加入其中。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/business/16/5/sharing-files-pydio-owncloud
|
||||
|
||||
作者：[ben van 't ende][a]
|
||||
译者：[martin2011qi](https://github.com/martin2011qi)
|
||||
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/benvantende
|
||||
[1]: https://pydio.com/
|
||||
[2]: https://sourceforge.net/projects/ajaxplorer/
|
||||
[3]: https://github.com/pydio/
|
||||
[4]: https://www.google.com/design/spec/material-design/introduction.html
|
||||
[5]: https://pydio.com/en/community
|
||||
[6]: https://pydio.com/en/community/contribute
|
||||
[7]: https://pydio.com/forum/f
|
||||
[8]: https://owncloud.org/
|
||||
[9]: https://wiki.geant.org/display/OCM/Open+Cloud+Mesh
|
||||
@ -0,0 +1,71 @@
|
||||
使用python 和asyncio编写在线多人游戏 - 第1部分
|
||||
===================================================================
|
||||
|
||||
你曾经把async和python关联起来过吗？在这里我将告诉你怎样做，而且在[working example][1]这个例子里面展示-一个流行的贪吃蛇游戏，这是为多人游戏而设计的。
|
||||
[Play game][2]
|
||||
|
||||
###1.简介
|
||||
|
||||
在技术和文化领域，大量的多人在线游戏毋庸置疑是我们这个世界的主流之一。同时，为一个MMO游戏写一个服务器一般和大量的预算与低水平的编程技术相关，在最近这几年，事情发生了很大的变化。基于动态语言的现代框架允许在稳健的硬件上面处理大量并发的用户连接。同时，HTML5 和 WebSockets 标准允许基于实时的图形游戏直接在web浏览器上创建客户端，而不需要任何的扩展。
|
||||
|
||||
对于创建可扩展非堵塞的服务器，Python可能不是最受欢迎的工具，尤其是和在这个领域最受欢迎的node.js相比。但是最近版本的python打算改变这种现状。[asyncio][3]的介绍和一个特别的[async/await][4] 语法使得异步代码看起来像常规的阻塞代码，这使得python成为一个值得信赖的异步编程语言。所以我将尝试利用这些新特点来创建一个多人在线游戏。
|
||||
|
||||
###2.异步
|
||||
一个游戏服务器应该处理最大数量的用户的并发连接和实时处理这些连接。一个典型的解决方案----创建线程，然而在这种情况下并不能解决这个问题。运行上千的线程需要CPU在它们之间不停的切换（这叫做上下文切换），这将开销非常大，效率很低下。更糟糕的是，因为，此外，它们会占用大量的内存。在python中，还有一个问题，python的解释器（CPython）并不是针对多线程设计的，它主要针对于单线程实现最大数量的行为。这就是为什么它使用GIL（global interpreter lock）,一个不允许同时运行多线程python代码的架构，来防止共享物体的不可控用法。正常情况下当当前线程正在等待的时候，解释器转换到另一个线程，通常是一个I/O的响应（像一个服务器的响应一样）。这允许在你的应用中有非阻塞I/O，因为每一个操作仅仅堵塞一个线程而不是堵塞整个服务器。然而，这也使得通常的多线程变得无用，因为它不允许你并发执行python代码，即使是在多核心的cpu上。同时在单线程中拥有非阻塞IO是完全有可能的，因而消除了经常切换上下文的需要。
|
||||
|
||||
实际上，你可以用纯python代码来实现一个单线程的非阻塞IO。你所需要的只是标准的[select][5]模块，这个模块可以让你写一个事件循环来等待未阻塞的socket的io。然而，这个方法需要你在一个地方定义所有app的逻辑，不久之后，你的app就会变成非常复杂的状态机。有一些框架可以简化这个任务，比较流行的是[tornade][6] 和 [twisted][7]。他们被用来使用回调方法实现复杂的协议（这和node.js比较相似）。这个框架运行在他自己的事件循环中，这个事件在定义的事件上调用你的回调。并且，这或许是一些情况的解决方案，但是它仍然需要使用回调的方式编程，这使你的代码碎片化。和写同步代码并且并发执行多个副本相比，就像我们会在普通的线程上做一样。这为什么在单个线程上是不可能的呢？
|
||||
|
||||
这就是为什么microthread出现的原因。这个想法是为了在一个线程上并发执行任务。当你在一个任务中调用阻塞的方法时，有一个叫做"manager" (或者“scheduler”)的东西在执行事件循环。当有一些事件准备处理的时候，一个manager会让等这个事件的“任务”单元去执行，直到自己停了下来。然后执行完之后就返回那个管理器（manager）。
|
||||
|
||||
>Microthreads are also called lightweight threads or green threads (a term which came from Java world). Tasks which are running concurrently in pseudo-threads are called tasklets, greenlets or coroutines.（Microthreads 也会被称为lightweight threads 或者 green threads（java中的一个术语）。在伪线程中并发执行的任务叫做tasklets，greenlets或者coroutines）.
|
||||
|
||||
microthreads的其中一种实现在python中叫做[Stackless Python][8]。这个被用在了一个叫[EVE online][9]的非常有名的在线游戏中，所以它变得非常有名。这个MMO游戏自称说在一个持久的宇宙中，有上千个玩家在做不同的活动，这些都是实时发生的。Stackless 是一个单独的python解释器，它代替了标准的栈调用并且直接控制流来减少上下文切换的开销。尽管这非常有效，这个解决方案不如使用标准解释器的“soft”库有名。像[eventlet][10]和[gevent][11] 的方式配备了标准的I / O库的补丁的I / O功能在内部事件循环执行。这使得将正常的阻塞代码转变成非阻塞的代码变得简单。这种方法的一个缺点是从代码看这并不明显，这被称为非阻塞。Python的新的版本介绍了本地协同程序作为生成器的高级形式。在Python 的3.4版本中，引入了asyncio库，这个库依赖于本地协同程序来提供单线程并发。但是在Python 3.5 协同程序变成了Python语言的一部分，使用新的关键字 async 和 await 来描述。这是一个简单的例子，这表明了使用asyncio来运行 并发任务。
|
||||
|
||||
```
|
||||
import asyncio
|
||||
|
||||
async def my_task(seconds):
|
||||
print("start sleeping for {} seconds".format(seconds))
|
||||
await asyncio.sleep(seconds)
|
||||
print("end sleeping for {} seconds".format(seconds))
|
||||
|
||||
all_tasks = asyncio.gather(my_task(1), my_task(2))
|
||||
loop = asyncio.get_event_loop()
|
||||
loop.run_until_complete(all_tasks)
|
||||
loop.close()
|
||||
```
|
||||
|
||||
我们启动了两个任务，一个睡眠1秒钟，另一个睡眠2秒钟，输出如下：
|
||||
|
||||
```
|
||||
start sleeping for 1 seconds
|
||||
start sleeping for 2 seconds
|
||||
end sleeping for 1 seconds
|
||||
end sleeping for 2 seconds
|
||||
```
|
||||
|
||||
正如你所看到的，协同程序不会阻塞彼此-----第二个任务在第一个结束之前启动。这发生的原因是asyncio.sleep是协同程序，它会返回一个调度器的执行直到时间过去。在下一节中，
|
||||
我们将会使用coroutine-based的任务来创建一个游戏循环。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/
|
||||
|
||||
作者：[Kyrylo Subbotin][a]
|
||||
译者：[xinglianfly](https://github.com/xinglianfly)
|
||||
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://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/
|
||||
[1]: http://snakepit-game.com/
|
||||
[2]: http://snakepit-game.com/
|
||||
[3]: https://docs.python.org/3/library/asyncio.html
|
||||
[4]: https://docs.python.org/3/whatsnew/3.5.html#whatsnew-pep-492
|
||||
[5]: https://docs.python.org/2/library/select.html
|
||||
[6]: http://www.tornadoweb.org/
|
||||
[7]: http://twistedmatrix.com/
|
||||
[8]: http://www.stackless.com/
|
||||
[9]: http://www.eveonline.com/
|
||||
[10]: http://eventlet.net/
|
||||
[11]: http://www.gevent.org/
|
||||
@ -0,0 +1,319 @@
|
||||
如何用Python和Flask建立部署一个Facebook信使机器人教程
|
||||
==========================================================================
|
||||
|
||||
这是我建立一个简单的Facebook信使机器人的记录。功能很简单，他是一个回显机器人，只是打印回用户写了什么。
|
||||
|
||||
回显服务器类似于服务器的“Hello World”例子。
|
||||
|
||||
这个项目的目的不是建立最好的信使机器人，而是获得建立一个小型机器人和每个事物是如何整合起来的感觉。
|
||||
|
||||
- [技术栈][1]
|
||||
- [机器人架构][2]
|
||||
- [机器人服务器][3]
|
||||
- [部署到 Heroku][4]
|
||||
- [创建 Facebook 应用][5]
|
||||
- [结论][6]
|
||||
|
||||
### 技术栈
|
||||
|
||||
使用到的技术栈:
|
||||
|
||||
- [Heroku][7] 做后端主机。免费层足够这个等级的教程。回显机器人不需要任何种类的数据持久，所以不需要数据库。
|
||||
- [Python][8] 是选择的一个语言。版本选择2.7，虽然它移植到 Pyhton 3 很容易，只需要很少的改动。
|
||||
- [Flask][9] 作为网站开发框架。它是非常轻量的框架，用在小型工程或微服务是完美的。
|
||||
- 最后 [Git][10] 版本控制系统用来维护代码和部署到 Heroku。
|
||||
- 值得一提：[Virtualenv][11]。这个 python 工具是用来创建清洁的 python 库“环境”的，你只用安装必要的需求和最小化的应用封装。
|
||||
|
||||
### 机器人架构
|
||||
|
||||
信使机器人是由一个服务器组成，响应两种请求：
|
||||
|
||||
- GET 请求被用来认证。他们与你注册的 FB 认证码一同被信使发出。
|
||||
- POST 请求被用来真实的通信。传统的工作流是，机器人将通过发送 POST 请求与用户发送的消息数据建立通信，我们将处理它，发送一个我们自己的 POST 请求回去。如果这一个完全成功（返回一个200 OK 状态）我们也响应一个200 OK 码给初始信使请求。
|
||||
这个教程应用将托管到Heroku，他提供了一个很好并且简单的接口来部署应用。如前所述,免费层可以满足这个教程。
|
||||
|
||||
在应用已经部署并且运行后，我们将创建一个 Facebook 应用然后连接它到我们的应用，以便信使知道发送请求到哪，这就是我们的机器人。
|
||||
|
||||
### 机器人服务器
|
||||
|
||||
基本的服务器代码可以在Github用户 [hult(Magnus Hult)][13] 的 [Chatbot][12] 工程上获取，经过一些代码修改只回显消息和一些我遇到的错误更正。最终版本的服务器代码：
|
||||
|
||||
```
|
||||
from flask import Flask, request
|
||||
import json
|
||||
import requests
|
||||
|
||||
app = Flask(__name__)
|
||||
|
||||
# 这需要填写被授予的页面通行令牌
|
||||
# 通过 Facebook 应用创建令牌。
|
||||
PAT = ''
|
||||
|
||||
@app.route('/', methods=['GET'])
|
||||
def handle_verification():
|
||||
print "Handling Verification."
|
||||
if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me':
|
||||
print "Verification successful!"
|
||||
return request.args.get('hub.challenge', '')
|
||||
else:
|
||||
print "Verification failed!"
|
||||
return 'Error, wrong validation token'
|
||||
|
||||
@app.route('/', methods=['POST'])
|
||||
def handle_messages():
|
||||
print "Handling Messages"
|
||||
payload = request.get_data()
|
||||
print payload
|
||||
for sender, message in messaging_events(payload):
|
||||
print "Incoming from %s: %s" % (sender, message)
|
||||
send_message(PAT, sender, message)
|
||||
return "ok"
|
||||
|
||||
def messaging_events(payload):
|
||||
"""Generate tuples of (sender_id, message_text) from the
|
||||
provided payload.
|
||||
"""
|
||||
data = json.loads(payload)
|
||||
messaging_events = data["entry"][0]["messaging"]
|
||||
for event in messaging_events:
|
||||
if "message" in event and "text" in event["message"]:
|
||||
yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape')
|
||||
else:
|
||||
yield event["sender"]["id"], "I can't echo this"
|
||||
|
||||
|
||||
def send_message(token, recipient, text):
|
||||
"""Send the message text to recipient with id recipient.
|
||||
"""
|
||||
|
||||
r = requests.post("https://graph.facebook.com/v2.6/me/messages",
|
||||
params={"access_token": token},
|
||||
data=json.dumps({
|
||||
"recipient": {"id": recipient},
|
||||
"message": {"text": text.decode('unicode_escape')}
|
||||
}),
|
||||
headers={'Content-type': 'application/json'})
|
||||
if r.status_code != requests.codes.ok:
|
||||
print r.text
|
||||
|
||||
if __name__ == '__main__':
|
||||
app.run()
|
||||
```
|
||||
|
||||
让我们分解代码。第一部分是引入所需：
|
||||
|
||||
```
|
||||
from flask import Flask, request
|
||||
import json
|
||||
import requests
|
||||
```
|
||||
|
||||
接下来我们定义两个函数（使用 Flask 特定的 app.route 装饰器），用来处理到我们的机器人的 GET 和 POST 请求。
|
||||
|
||||
```
|
||||
@app.route('/', methods=['GET'])
|
||||
def handle_verification():
|
||||
print "Handling Verification."
|
||||
if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me':
|
||||
print "Verification successful!"
|
||||
return request.args.get('hub.challenge', '')
|
||||
else:
|
||||
print "Verification failed!"
|
||||
return 'Error, wrong validation token'
|
||||
```
|
||||
|
||||
当我们创建 Facebook 应用时声明由信使发送的 verify_token 对象。我们必须对自己进行认证。最后我们返回“hub.challenge”给信使。
|
||||
|
||||
处理 POST 请求的函数更有趣
|
||||
|
||||
```
|
||||
@app.route('/', methods=['POST'])
|
||||
def handle_messages():
|
||||
print "Handling Messages"
|
||||
payload = request.get_data()
|
||||
print payload
|
||||
for sender, message in messaging_events(payload):
|
||||
print "Incoming from %s: %s" % (sender, message)
|
||||
send_message(PAT, sender, message)
|
||||
return "ok"
|
||||
```
|
||||
|
||||
当调用我们抓取的消息负载时，使用函数 messaging_events 来中断它并且提取发件人身份和真实发送消息，生成一个 python 迭代器循环遍历。请注意信使发送的每个请求有可能多于一个消息。
|
||||
|
||||
```
|
||||
def messaging_events(payload):
|
||||
"""Generate tuples of (sender_id, message_text) from the
|
||||
provided payload.
|
||||
"""
|
||||
data = json.loads(payload)
|
||||
messaging_events = data["entry"][0]["messaging"]
|
||||
for event in messaging_events:
|
||||
if "message" in event and "text" in event["message"]:
|
||||
yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape')
|
||||
else:
|
||||
yield event["sender"]["id"], "I can't echo this"
|
||||
```
|
||||
|
||||
迭代完每个消息时我们调用send_message函数然后我们执行POST请求回给使用Facebook图形消息接口信使。在这期间我们一直没有回应我们阻塞的原始信使请求。这会导致超时和5XX错误。
|
||||
|
||||
上述的发现错误是中断期间我偶然发现的，当用户发送表情时其实的是当成了 unicode 标识，无论如何 Python 发生了误编码。我们以发送回垃圾结束。
|
||||
|
||||
这个 POST 请求回到信使将不会结束，这会导致发生5xx状态返回给原始的请求，显示服务不可用。
|
||||
|
||||
通过使用`encode('unicode_escape')`转义消息然后在我们发送回消息前用`decode('unicode_escape')`解码消息就可以解决。
|
||||
|
||||
```
|
||||
def send_message(token, recipient, text):
|
||||
"""Send the message text to recipient with id recipient.
|
||||
"""
|
||||
|
||||
r = requests.post("https://graph.facebook.com/v2.6/me/messages",
|
||||
params={"access_token": token},
|
||||
data=json.dumps({
|
||||
"recipient": {"id": recipient},
|
||||
"message": {"text": text.decode('unicode_escape')}
|
||||
}),
|
||||
headers={'Content-type': 'application/json'})
|
||||
if r.status_code != requests.codes.ok:
|
||||
print r.text
|
||||
```
|
||||
|
||||
### 部署到 Heroku
|
||||
|
||||
一旦代码已经建立成我想要的样子时就可以进行下一步。部署应用。
|
||||
|
||||
当然，但是怎么做？
|
||||
|
||||
我之前已经部署了应用到 Heroku （主要是 Rails）然而我总是遵循某种教程，所以配置已经创建。在这种情况下，尽管我必须从头开始。
|
||||
|
||||
幸运的是有官方[Heroku文档][14]来帮忙。这篇文章很好地说明了运行应用程序所需的最低限度。
|
||||
|
||||
长话短说，我们需要的除了我们的代码还有两个文件。第一个文件是“requirements.txt”他列出了运行应用所依赖的库。
|
||||
|
||||
需要的第二个文件是“Procfile”。这个文件通知 Heroku 如何运行我们的服务。此外这个文件最低限度如下：
|
||||
|
||||
>web: gunicorn echoserver:app
|
||||
|
||||
heroku解读他的方式是我们的应用通过运行 echoserver.py 开始并且应用将使用 gunicorn 作为网站服务器。我们使用一个额外的网站服务器是因为与性能相关并在上面的Heroku文档里解释了：
|
||||
|
||||
>Web 应用程序并发处理传入的HTTP请求比一次只处理一个请求的Web应用程序，更有效利地用动态资源。由于这个原因，我们建议使用支持并发请求的 web 服务器处理开发和生产运行的服务。
|
||||
|
||||
>Django 和 Flask web 框架特性方便内建 web 服务器，但是这些阻塞式服务器一个时刻只处理一个请求。如果你部署这种服务到 Heroku上，你的动态资源不会充分使用并且你的应用会感觉迟钝。
|
||||
|
||||
>Gunicorn 是一个纯 Python HTTP 的 WSGI 引用服务器。允许你在单独一个动态资源内通过并发运行多 Python 进程的方式运行任一 Python 应用。它提供了一个完美性能，弹性，简单配置的平衡。
|
||||
|
||||
回到我们提到的“requirements.txt”文件，让我们看看它如何结合 Virtualenv 工具。
|
||||
|
||||
在任何时候，你的开发机器也许有若干已安装的 python 库。当部署应用时你不想这些库被加载因为很难辨认出你实际使用哪些库。
|
||||
|
||||
Virtualenv 创建一个新的空白虚拟环境，因此你可以只安装你应用需要的库。
|
||||
|
||||
你可以检查当前安装使用哪些库的命令如下：
|
||||
|
||||
```
|
||||
kostis@KostisMBP ~ $ pip freeze
|
||||
cycler==0.10.0
|
||||
Flask==0.10.1
|
||||
gunicorn==19.6.0
|
||||
itsdangerous==0.24
|
||||
Jinja2==2.8
|
||||
MarkupSafe==0.23
|
||||
matplotlib==1.5.1
|
||||
numpy==1.10.4
|
||||
pyparsing==2.1.0
|
||||
python-dateutil==2.5.0
|
||||
pytz==2015.7
|
||||
requests==2.10.0
|
||||
scipy==0.17.0
|
||||
six==1.10.0
|
||||
virtualenv==15.0.1
|
||||
Werkzeug==0.11.10
|
||||
```
|
||||
|
||||
注意：pip 工具应该已经与 Python 一起安装在你的机器上。
|
||||
|
||||
如果没有，查看[官方网站][15]如何安装他。
|
||||
|
||||
现在让我们使用 Virtualenv 来创建一个新的空白环境。首先我们给我们的工程创建一个新文件夹，然后进到目录下：
|
||||
|
||||
```
|
||||
kostis@KostisMBP projects $ mkdir echoserver
|
||||
kostis@KostisMBP projects $ cd echoserver/
|
||||
kostis@KostisMBP echoserver $
|
||||
```
|
||||
|
||||
现在来创建一个叫做 echobot 新的环境。运行下面的 source 命令激活它，然后使用 pip freeze 检查，我们能看到现在是空的。
|
||||
|
||||
```
|
||||
kostis@KostisMBP echoserver $ virtualenv echobot
|
||||
kostis@KostisMBP echoserver $ source echobot/bin/activate
|
||||
(echobot) kostis@KostisMBP echoserver $ pip freeze
|
||||
(echobot) kostis@KostisMBP echoserver $
|
||||
```
|
||||
|
||||
我们可以安装需要的库。我们需要是 flask，gunicorn，和 requests，他们被安装完我们就创建 requirements.txt 文件：
|
||||
|
||||
```
|
||||
(echobot) kostis@KostisMBP echoserver $ pip install flask
|
||||
(echobot) kostis@KostisMBP echoserver $ pip install gunicorn
|
||||
(echobot) kostis@KostisMBP echoserver $ pip install requests
|
||||
(echobot) kostis@KostisMBP echoserver $ pip freeze
|
||||
click==6.6
|
||||
Flask==0.11
|
||||
gunicorn==19.6.0
|
||||
itsdangerous==0.24
|
||||
Jinja2==2.8
|
||||
MarkupSafe==0.23
|
||||
requests==2.10.0
|
||||
Werkzeug==0.11.10
|
||||
(echobot) kostis@KostisMBP echoserver $ pip freeze > requirements.txt
|
||||
```
|
||||
|
||||
毕竟上文已经被运行，我们用 python 代码创建 echoserver.py 文件然后用之前提到的命令创建 Procfile，我们应该以下面的文件/文件夹结束：
|
||||
|
||||
```
|
||||
(echobot) kostis@KostisMBP echoserver $ ls
|
||||
Procfile echobot echoserver.py requirements.txt
|
||||
```
|
||||
|
||||
我们现在准备上传到 Heroku。我们需要做两件事。第一是安装 Heroku toolbet 如果你还没安装到你的系统中（详细看[Heroku][16]）。第二通过[网页接口][17]创建一个新的 Heroku 应用。
|
||||
|
||||
点击右上的大加号然后选择“Create new app”。
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/
|
||||
|
||||
作者：[Konstantinos Tsaprailis][a]
|
||||
译者：[wyangsun](https://github.com/wyangsun)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://github.com/kostistsaprailis
|
||||
[1]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#tech-stack
|
||||
[2]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#bot-architecture
|
||||
[3]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#the-bot-server
|
||||
[4]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#deploying-to-heroku
|
||||
[5]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#creating-the-facebook-app
|
||||
[6]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#conclusion
|
||||
[7]: https://www.heroku.com
|
||||
[8]: https://www.python.org
|
||||
[9]: http://flask.pocoo.org
|
||||
[10]: https://git-scm.com
|
||||
[11]: https://virtualenv.pypa.io/en/stable
|
||||
[12]: https://github.com/hult/facebook-chatbot-python
|
||||
[13]: https://github.com/hult
|
||||
[14]: https://devcenter.heroku.com/articles/python-gunicorn
|
||||
[15]: https://pip.pypa.io/en/stable/installing
|
||||
[16]: https://toolbelt.heroku.com
|
||||
[17]: https://dashboard.heroku.com/apps
|
||||
|
||||
|
||||
@ -1,68 +0,0 @@
|
||||
教你用 google-drive-ocamlfuse 在 Linux 上挂载 Google Drive
|
||||
=====================
|
||||
|
||||
>如果你在找一个方便的方式在 Linux 机器上挂载你的 Google Drive 文件夹， Jack Wallen 将教你怎么使用 google-drive-ocamlfuse 来挂载 Google Drive。
|
||||
|
||||
|
||||
>图片来源: Jack Wallen
|
||||
|
||||
Google 还没有发行 Linux 版本的 Google Drive 应用，尽管现在有很多方法从 Linux 中访问你的 Drive 文件。
|
||||
（注：不清楚 app 需不需要翻译成应用，这里翻译了）
|
||||
|
||||
如果你喜欢界面化的工具，你可以选择 Insync。如果你喜欢用命令行，这有很多工具，像 Grive2 和用 Ocaml 语言编写的、非常容易使用的、基于 FUSE 的系统（注：there are tools such as Grive2 and the incredibly easy to use FUSE-based system written in Ocaml. 这一句感觉翻译不出来）。我将会用后面这种方式演示如何在 Linux 桌面上挂载你的 Google Drive。尽管这是通过命令行完成的，但是它的用法会简单到让你吃惊。它太简单了以至于谁都能做到。
|
||||
|
||||
系统特点：
|
||||
|
||||
- 对普通文件/文件夹有完全的读写权限
|
||||
- 对于 Google Docs，sheets，slides 这三个应用只读
|
||||
- 能够访问 Drive 回收站（.trash）
|
||||
- 处理重复文件功能
|
||||
- 支持多个帐号
|
||||
|
||||
接下来完成 google-drive-ocamlfuse 在 Ubuntu 16.04 桌面的安装，然后你就能够访问云盘上的文件了。
|
||||
|
||||
### 安装
|
||||
|
||||
1. 打开终端。
|
||||
2. 用`sudo add-apt-repository ppa:alessandro-strada/ppa`命令添加必要的 PPA
|
||||
3. 出现提示的时候，输入密码并按下回车。
|
||||
4. 用`sudo apt-get update`命令更新应用。
|
||||
5. 输入`sudo apt-get install google-drive-ocamlfuse`命令安装软件。
|
||||
（注：这里，我把所有的命令加上着重标记了）
|
||||
|
||||
### 授权
|
||||
|
||||
接下来就是授权 google-drive-ocamlfuse，让它有权限访问你的 Google 账户。先回到终端窗口敲下命令 google-drive-ocamlfuse，这个命令将会打开一个浏览器窗口，它会提示你登陆你的 Google 帐号或者如果你已经登陆了 Google 帐号，它会询问是否允许 google-drive-ocamlfuse 访问 Google 账户。如果你还没有登陆，先登陆然后点击允许。接下来的窗口（在 Ubuntu 16.04 桌面上会出现，但不会出现在基本系统 Freya 桌面上）将会询问你是否授给 gdfuse 和 OAuth2 Endpoint访问你的 Google 账户的权限，再次点击允许。然后出现的窗口就会告诉你等待授权令牌下载完成，这个时候就能最小化浏览器了。当你的终端提示像图 A 一样的内容，你就能知道令牌下载完了，并且你已经可以挂载 Google Drive 了。
|
||||
|
||||
**图 A**
|
||||
|
||||
|
||||
>图片来源: Jack Wallen
|
||||
|
||||
**应用已经得到授权，你可以进行后面的工作。**
|
||||
|
||||
### 挂载 Google Drive
|
||||
|
||||
在挂载 Google Drive 之前，你得先创建一个文件夹，作为挂载点。在终端里，敲下`mkdir ~/google-drive`命令在你的家目录下创建一个新的文件夹。最后敲下命令`google-drive-ocamlfuse ~/google-drive`将你的 Google Drive 挂载到 google-drive 文件夹中。
|
||||
|
||||
这时你可以查看本地 google-drive 文件夹中包含的 Google Drive 文件/文件夹。你能够把 Google Drive 当作本地文件系统来进行工作。
|
||||
|
||||
当你想 卸载 google-drive 文件夹，输入命令 `fusermount -u ~/google-drive`。
|
||||
|
||||
### 没有 GUI，但它特别好用
|
||||
|
||||
我发现这个特别的系统非常容易使用，在同步 Google Drive 时它出奇的快，并且这可以作为一种巧妙的方式备份你的 Google Drive 账户。
|
||||
|
||||
试试 google-drive-ocamlfuse，看看你能用它做出什么有趣的事。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.techrepublic.com/article/how-to-mount-your-google-drive-on-linux-with-google-drive-ocamlfuse/
|
||||
|
||||
作者：[Jack Wallen ][a]
|
||||
译者：[GitFuture](https://github.com/GitFuture)
|
||||
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]: http://www.techrepublic.com/search/?a=jack+wallen
|
||||
@ -1,228 +0,0 @@
|
||||
使用 OpenCV 识别图片中的猫
|
||||
=======================================
|
||||
|
||||
|
||||
|
||||
你知道 OpenCV 可以识别在图片中识别猫脸吗？还是在开箱即用的情况下，无需多余的附件。
|
||||
|
||||
我也不知道。
|
||||
|
||||
但是在看完'[Kendrick Tan broke the story][1]'这个故事之后, 我需要亲自体验一下...去看看到OpenCV 是如何在我没有察觉到的情况下，将这一个功能添加进了他的软件库。
|
||||
|
||||
作为这个博客的大纲，我将会展示如何使用 OpenCV 的猫检测器在图片中识别猫脸。同样的，你也可以在视频流中使用该技术。
|
||||
|
||||
> 想找这篇博客的源码？[请点这][2]。
|
||||
|
||||
|
||||
### 使用 OpenCV 在图片中检测猫
|
||||
|
||||
如果你看一眼[OpenCV 的代码库][3]，尤其是在[haarcascades 目录][4](OpenCV 用来保存处理他对多种目标检测的Cascade预先训练的级联图像分类)， 你将会注意到这两个文件:
|
||||
|
||||
- haarcascade_frontalcatface.xml
|
||||
- haarcascade_frontalcatface_extended.xml
|
||||
|
||||
这两个 Haar Cascade 文件都将被用来在图片中检测猫脸。实际上，我使用了相同的方式来生成这篇博客顶端的图片。
|
||||
|
||||
在做了一些调查工作之后，我发现训练这些记过并且将其提供给 OpenCV 仓库的是鼎鼎大名的 [Joseph Howse][5]，他在计算机视觉领域有着很高的声望。
|
||||
|
||||
在博客的剩余部分，我将会展示给你如何使用 Howse 的 Haar 级联模型来检测猫。
|
||||
|
||||
让我们开工。新建一个叫 cat_detector.py 的文件，并且输入如下的代码:
|
||||
|
||||
### 使用 OpenCVPython 来检测猫
|
||||
|
||||
```
|
||||
# import the necessary packages
|
||||
import argparse
|
||||
import cv2
|
||||
|
||||
# construct the argument parse and parse the arguments
|
||||
ap = argparse.ArgumentParser()
|
||||
ap.add_argument("-i", "--image", required=True,
|
||||
help="path to the input image")
|
||||
ap.add_argument("-c", "--cascade",
|
||||
default="haarcascade_frontalcatface.xml",
|
||||
help="path to cat detector haar cascade")
|
||||
args = vars(ap.parse_args())
|
||||
```
|
||||
|
||||
第2和第3行主要是导入了必要的 python 包。6-12行主要是我们的命令行参数。我们在这只需要使用单独的参数'--image'。
|
||||
|
||||
我们可以指定一个 Haar cascade 的路径通过 `--cascade` 参数。默认使用 `haarcascades_frontalcatface.xml`，同时需要保证这个文件和你的 `cat_detector.py` 在同一目录下。
|
||||
|
||||
注意:我已经打包了猫的检测代码，还有在这个教程里的样本图片。你可以在博客的'Downloads' 部分下载到。如果你是刚刚接触 Python+OpenCV(或者 Haar 级联模型), 我会建议你下载 zip 压缩包，这个会方便你进行操作。
|
||||
|
||||
接下来，就是检测猫的时刻了:
|
||||
|
||||
```
|
||||
# load the input image and convert it to grayscale
|
||||
image = cv2.imread(args["image"])
|
||||
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
|
||||
|
||||
# load the cat detector Haar cascade, then detect cat faces
|
||||
# in the input image
|
||||
detector = cv2.CascadeClassifier(args["cascade"])
|
||||
rects = detector.detectMultiScale(gray, scaleFactor=1.3,
|
||||
minNeighbors=10, minSize=(75, 75))
|
||||
```
|
||||
|
||||
在15，16行，我们从硬盘上读取了图片，并且进行灰度化(一个常用的图片预处理，方便 Haar cascade 进行分类，尽管不是必须)
|
||||
|
||||
20行，我们加载了Haar casacade，即猫检测器，并且初始化了 cv2.CascadeClassifier 对象。
|
||||
|
||||
使用 OpenCV 检测猫脸的步骤是21，22行，通过调用 detectMultiScale 方法。我们使用四个参数来调用。包括：
|
||||
|
||||
1. 灰度化的图片，即样本图片。
|
||||
2. scaleFactor 参数，[图片金字塔][6]使用的检测猫脸时的检测粒度。一个更大的粒度将会加快检测的速度，但是会对准确性产生影响。相反的，一个更小的粒度将会影响检测的时间，但是会增加正确性。但是，细粒度也会增加错误的检测数量。你可以看博客的 'Haar 级联模型笔记' 部分来获得更多的信息。
|
||||
3. minNeighbors 参数控制了检测的最小数量,即在给定区域最小的检测猫脸的次数。这个参数很好的可以排除错误的检测结果。
|
||||
4. 最后，minSize 参数很好的自我说明了用途。即最后图片的最小大小，这个例子中就是 75\*75
|
||||
|
||||
detectMultiScale 函数 return rects，这是一个4维数组链表。这些item 中包含了猫脸的(x,y)坐标值，还有宽度，高度。
|
||||
|
||||
最后，让我们在图片上画下这些矩形来标识猫脸：
|
||||
|
||||
```
|
||||
# loop over the cat faces and draw a rectangle surrounding each
|
||||
for (i, (x, y, w, h)) in enumerate(rects):
|
||||
cv2.rectangle(image, (x, y), (x + w, y + h), (0, 0, 255), 2)
|
||||
cv2.putText(image, "Cat #{}".format(i + 1), (x, y - 10),
|
||||
cv2.FONT_HERSHEY_SIMPLEX, 0.55, (0, 0, 255), 2)
|
||||
|
||||
# show the detected cat faces
|
||||
cv2.imshow("Cat Faces", image)
|
||||
cv2.waitKey(0)
|
||||
```
|
||||
|
||||
给相关的区域(举个例子，rects)，我们在25行依次历遍它。
|
||||
|
||||
在26行，我们在每张猫脸的周围画上一个矩形。27，28行展示了一个整数，即图片中猫的数量。
|
||||
|
||||
最后，31，32行在屏幕上展示了输出的图片。
|
||||
|
||||
### 猫检测结果
|
||||
|
||||
为了测试我们的 OpenCV 毛检测器，可以在文章的最后，下载教程的源码。
|
||||
|
||||
然后，在你解压缩之后，你将会得到如下的三个文件/目录:
|
||||
|
||||
1. cat_detector.py:我们的主程序
|
||||
2. haarcascade_frontalcatface.xml: Haar cascade 猫检测资源
|
||||
3. images:我们将会使用的检测图片目录。
|
||||
|
||||
到这一步，执行以下的命令:
|
||||
|
||||
使用 OpenCVShell 检测猫。
|
||||
|
||||
```
|
||||
$ python cat_detector.py --image images/cat_01.jpg
|
||||
```
|
||||
|
||||
|
||||
>1. 在图片中检测猫脸，甚至是猫的一部分。
|
||||
|
||||
注意，我们已经可以检测猫脸了，即使他的其余部分是被隐藏的。
|
||||
|
||||
试下另外的一张图片:
|
||||
|
||||
```
|
||||
python cat_detector.py --image images/cat_02.jpg
|
||||
```
|
||||
|
||||
|
||||
>2. 第二个例子就是在略微不同的猫脸中检测。
|
||||
|
||||
这次的猫脸和第一次的明显不同，因为它在'Meow'的中央。这种情况下，我们依旧能检测到正确的猫脸。
|
||||
|
||||
这张图片的结果也是正确的:
|
||||
|
||||
```
|
||||
$ python cat_detector.py --image images/cat_03.jpg
|
||||
```
|
||||
|
||||
|
||||
>3. 使用 OpenCV 和 python 检测猫脸
|
||||
|
||||
我们最后的一个样例就是在一张图中检测多张猫脸:
|
||||
|
||||
```
|
||||
$ python cat_detector.py --image images/cat_04.jpg
|
||||
```
|
||||
|
||||
|
||||
>Figure 4: Detecting multiple cats in the same image with OpenCV
|
||||
>4. 在同一张图片中使用 OpenCV 检测多只猫
|
||||
|
||||
注意，Haar cascade 的返回值并不是有序的。这种情况下，中间的那只猫会被标记成第三只。你可以通过判断他们的(x, y)坐标来自己排序。
|
||||
|
||||
#### 精度的 Tips
|
||||
|
||||
xml 文件中的注释，非常重要，Joseph Hower 提到了猫 脸检测器有可能会将人脸识别成猫脸。
|
||||
|
||||
这种情况下，他推荐使用两种检测器(人脸&猫脸)，然后将出现在人脸识别结果中的结果剔除掉。
|
||||
|
||||
#### Haar 级联模型注意事项
|
||||
|
||||
这个方法首先出现在 Paul Viola 和 Michael Jones 2001 年发布的 [Rapid Object Detection using a Boosted Cascade of Simple Features] 论文中。现在它已经成为了计算机识别领域引用最多的成果之一。
|
||||
|
||||
这个算法能够识别图片中的对象，无论地点，规模。并且，他也能在现有的硬件条件下实现实时计算。
|
||||
|
||||
在他们的论文中，Viola 和 Jones 关注在训练人脸检测器；但是，这个框架也能用来检测各类事物，如汽车，香蕉，路标等等。
|
||||
|
||||
#### 有问题？
|
||||
|
||||
Haar 级联模型最大的问题就是如何确定 detectMultiScale 方法的参数正确。特别是 scaleFactor 和 minNeighbors 参数。你很容易陷入，一张一张图片调参数的坑，这个就是该模型很难被实用化的原因。
|
||||
|
||||
这个 scaleFactor 变量控制了用来检测图片各种对象的[图像棱锥图][8]。如何参数过大，你就会得到更少的特征值，这会导致你无法在图层中识别一些目标。
|
||||
|
||||
换句话说，如果参数过低，你会检测出过多的图层。这虽然可以能帮助你检测更多的对象。但是他会造成计算速度的降低还会提高错误率。
|
||||
|
||||
为了避免这个，我们通常使用[Histogram of Oriented Gradients + Linear SVM detection][9]。
|
||||
|
||||
HOG + 线性 SVM 框架，它的参数更加容易的进行调优。而且也有更低的错误识别率，但是最大的缺点及时无法实时运算。
|
||||
|
||||
### 对对象识别感兴趣？并且希望了解更多？
|
||||
|
||||
|
||||
>5. 在 PyImageSearch Gurus 课程中学习如何构建自定义的对象识别器。
|
||||
|
||||
如果你对学习如何训练自己的自定义对象识别器，请务必要去学习 PyImageSearch Gurus 的课程。
|
||||
|
||||
在这个课程中，我提供了15节课还有超过168页的教程，来教你如何从0开始构建自定义的对象识别器。你会掌握如何应用 HOG+线性 SVM 计算框架来构建自己的对象识别器。
|
||||
|
||||
### 总结
|
||||
|
||||
在这篇博客里，我们学习了如何使用默认的 Haar 级联模型来识别图片中的猫脸。这些 Haar casacades 是通过[Joseph Howse][9] 贡献给 OpenCV 项目的。我是在[这篇文章][10]中开始注意到这个。
|
||||
|
||||
尽管 Haar 级联模型相当有用，但是我们也经常用 HOG 和 线性 SVM 替代。因为后者相对而言更容易使用，并且可以有效地降低错误的识别概率。
|
||||
|
||||
我也会在[在 PyImageSearch Gurus 的课程中][11]详细的讲述如何使用 HOG 和线性 SVM 对象识别器，来识别包括汽车，路标在内的各种事物。
|
||||
|
||||
不管怎样，我希望你享受这篇博客。
|
||||
|
||||
在你离开之前，确保你会使用这下面的表单注册 PyImageSearch Newsletter。这样你能收到最新的消息。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.pyimagesearch.com/2016/06/20/detecting-cats-in-images-with-opencv/
|
||||
|
||||
作者：[Adrian Rosebrock][a]
|
||||
译者：[译者ID](https://github.com/MikeCoder)
|
||||
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]: http://www.pyimagesearch.com/author/adrian/
|
||||
[1]: http://kendricktan.github.io/find-cats-in-photos-using-computer-vision.html
|
||||
[2]: http://www.pyimagesearch.com/2016/06/20/detecting-cats-in-images-with-opencv/#
|
||||
[3]: https://github.com/Itseez/opencv
|
||||
[4]: https://github.com/Itseez/opencv/tree/master/data/haarcascades
|
||||
[5]: http://nummist.com/
|
||||
[6]: http://www.pyimagesearch.com/2015/03/16/image-pyramids-with-python-and-opencv/
|
||||
[7]: https://www.cs.cmu.edu/~efros/courses/LBMV07/Papers/viola-cvpr-01.pdf
|
||||
[8]: http://www.pyimagesearch.com/2015/03/16/image-pyramids-with-python-and-opencv/
|
||||
[9]: http://www.pyimagesearch.com/2014/11/10/histogram-oriented-gradients-object-detection/
|
||||
[10]: http://kendricktan.github.io/find-cats-in-photos-using-computer-vision.html
|
||||
[11]: https://www.pyimagesearch.com/pyimagesearch-gurus/
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,124 @@
|
||||
Python高级图像处理
|
||||
======================================
|
||||
|
||||
|
||||
|
||||
构建图像搜索引擎并不是一件容易的任务。这里有几个概念、工具、想法和技术需要实现。主要的图像处理概念之一是逆图像查询(RIQ)或者说逆图像搜索。Google、Cloudera、Sumo Logic 和 Birst等公司在使用逆图像搜索中名列前茅。通过分析图像和使用数据挖掘RIQ提供了很好的洞察分析能力。
|
||||
|
||||
### 顶级公司与逆图像搜索
|
||||
|
||||
有很多顶级的技术公司使用RIQ来产生最好的收益。例如：在2014年Pinterest第一次带来了视觉搜索。随后在2015年发布了一份白皮书，揭示了其架构。逆图像搜索让Pinterest获得对时尚对象的视觉特征和显示类似的产品建议的能力。
|
||||
|
||||
众所周知，谷歌图片使用逆图像搜索允许用户上传一张图片然后搜索相关联的图片。通过使用先进的算法对提交的图片进行分析和数学建模。然后和谷歌数据库中无数的其他图片进行比较得到相似的结果。
|
||||
|
||||
**这是opencv 2.4.9特征比较报告一个图表：**
|
||||
|
||||
|
||||
|
||||
### 算法 & Python库
|
||||
|
||||
在我们使用它工作之前，让我们过一遍构建图像搜索引擎的Python库的主要元素：
|
||||
|
||||
### 专利算法
|
||||
|
||||
#### 尺度不变特征变换算法（SIFT - Scale-Invariant Feature Transform）
|
||||
|
||||
1. 非自由功能的一个专利技术，利用图像识别符，以识别相似图像，甚至那些从不同的角度，大小，深度和规模点击，它们被包括在搜索结果中。[点击这里][4]查看SIFT详细视频。
|
||||
2. SIFT能与从许多图片中提取的特征的大型数据库正确的匹配搜索条件。
|
||||
3. 从不同的方面来匹配相同的图像和匹配不变特征来获得搜索结果是SIFT的另一个特征。了解更多关于尺度不变[关键点][5]
|
||||
|
||||
#### 加速鲁棒特征(SURF - Speeded Up Robust Features)算法
|
||||
|
||||
1. [SURF][1] 也是一种非自由功能的专利技术而且还是一种“加速”的SIFT版本。不像SIFT，
|
||||
|
||||
2. SURF依赖于Hessian矩阵行列式的位置和尺度。
|
||||
|
||||
3. 在许多应用中，旋转不变性是不是一个必要条件。所以找不到这个方向的速度加快了这个过程。
|
||||
|
||||
4. SURF包括几种特性，在每一步的速度提高。比SIFT快三倍的速度，SIFT擅长旋转和模糊化。然而它不擅长处理照明和变换视角。
|
||||
|
||||
5. Open CV，一个程序功能库提供SURF相似的功能，SURF.compute()和SURF.Detect()可以用来找到描述符和要点。阅读更多关于SURF[点击这里][2]
|
||||
|
||||
### 开源算法
|
||||
|
||||
#### KAZE 算法
|
||||
|
||||
1. KAZE是一个开源的非线性尺度空间的二维多尺度和新的特征检测和描述算法。在加性算子分裂的有效技术（AOS）和可变电导扩散是用来建立非线性尺度空间。
|
||||
|
||||
2. 多尺度图像处理基础是简单的创建一个图像的尺度空间，同时用正确的函数过滤原始图像，提高时间或规模。
|
||||
|
||||
#### AKAZE (Accelerated-KAZE) 算法
|
||||
|
||||
1. 顾名思义，这是一个更快的图像搜索方式，找到匹配的关键点在两幅图像之间。AKAZE 使用二进制描述符和非线性尺度空间来平衡精度和速度。
|
||||
|
||||
#### BRISK (Binary Robust Invariant Scalable Keypoints) 算法
|
||||
|
||||
1. BRISK 非常适合描述关键点的检测与匹配。
|
||||
|
||||
2. 是一种高度自适应的算法，基于尺度空间的快速检测器和一个位字符串描述符，有助于加快搜索显着。
|
||||
|
||||
3. 尺度空间关键点检测与关键点描述帮助优化手头相关任务的性能
|
||||
|
||||
#### FREAK (Fast Retina Keypoint)
|
||||
|
||||
1. 这个新的关键点描述的灵感来自人的眼睛。通过图像强度比能有效地计算一个二进制串级联。FREAK算法相比BRISK，SURF和SIFT算法有更快的计算与较低的内存负载。
|
||||
|
||||
#### ORB (Oriented FAST and Rotated BRIEF)
|
||||
|
||||
1. 快速的二进制描述符，ORB具有抗噪声和旋转不变性。ORB建立在FAST关键点检测器和BRIEF描述符之上，有成本低、性能好的元素属性。
|
||||
|
||||
2. 除了快速和精确的定位元件，有效地计算定向的BRIEF，分析变动和面向BRIEF特点相关，是另一个ORB的特征。
|
||||
|
||||
### Python库
|
||||
|
||||
#### Open CV
|
||||
|
||||
1. Open CV提供学术和商业用途。一个开源的机器学习和计算机视觉库，OpenCV便于组织利用和修改代码。
|
||||
|
||||
2. 超过2500个优化算法，包括国家最先进的机器学习和计算机视觉算法服务与各种图像搜索--人脸检测、目标识别、摄像机目标跟踪，从图像数据库中寻找类似图像、眼球运动跟随、风景识别等。
|
||||
|
||||
3. 像谷歌，IBM，雅虎，IBM，索尼，本田，微软和英特尔这样的大公司广泛的使用OpenCV。
|
||||
|
||||
4. OpenCV拥有python，java，C，C++和MATLAB接口，同时支持Windows，Linux，Mac OS和Android。
|
||||
|
||||
#### Python图像库 （PIL）
|
||||
|
||||
1. Python图像库（PIL）支持多种文件格式，同时提供图像处理和图形解决方案。开源的PIL为你的Python解释器添加图像处理能力。
|
||||
2. 标准的图像处理能力包括图像增强、透明和屏蔽作用、图像过滤、像素操作等。
|
||||
|
||||
详细的数据和图表，请看OpenCV 2.4.9 特征比较报告。[这里][3]
|
||||
|
||||
### 构建图像搜索引擎
|
||||
|
||||
图像搜索引擎可以从预置集图像库选择相似的图像。其中最受欢迎的是谷歌的著名的图像搜索引擎。对于初学者来说，有不同的方法来建立这样的系统。提几个如下：
|
||||
|
||||
1. 采用图像提取、图像描述提取、元数据提取和搜索结果提取，建立图像搜索引擎。
|
||||
2. 定义你的图像描述符，数据集索引，定义你的相似性度量，然后搜索和排名。
|
||||
3. 选择要搜索的图像，选择用于进行搜索的目录，所有图片的搜索目录，创建图片特征索引，评估相同的搜索图片的功能，在搜索中匹配图片，并获得匹配的图片。
|
||||
|
||||
我们的方法基本上就比较grayscaled版本的图像，逐渐移动到复杂的特征匹配算法如SIFT和SURF，最后沉淀下来的是开源的解决方案称为BRISK。所有这些算法提供了有效的结果，在性能和延迟的细微变化。建立在这些算法上的引擎有许多应用，如分析流行统计的图形数据，在图形内容中识别对象，以及更多。
|
||||
|
||||
**例如**：一个图像搜索引擎需要由一个IT公司作为客户机来建立。因此，如果一个品牌的标志图像被提交在搜索中，所有相关的品牌形象搜索显示结果。所得到的结果也可以通过客户端分析，使他们能够根据地理位置估计品牌知名度。但它还比较年轻，RIQ或反向图像搜索尚未被完全挖掘利用。
|
||||
|
||||
这就结束了我们的文章，使用Python构建图像搜索引擎。浏览我们的博客部分来查看最新的编程技术。
|
||||
|
||||
数据来源：OpenCV 2.4.9 特征比较报告(computer-vision-talks.com)
|
||||
|
||||
(Ananthu Nair 的指导与补充)
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.cuelogic.com/blog/advanced-image-processing-with-python/
|
||||
|
||||
作者：[Snehith Kumbla][a]
|
||||
译者：[Johnny-Liao](https://github.com/Johnny-Liao)
|
||||
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]: http://www.cuelogic.com/blog/author/snehith-kumbla/
|
||||
[1]: http://docs.opencv.org/3.0-beta/doc/py_tutorials/py_feature2d/py_surf_intro/py_surf_intro.html
|
||||
[2]: http://www.vision.ee.ethz.ch/~surf/eccv06.pdf
|
||||
[3]: https://docs.google.com/spreadsheets/d/1gYJsy2ROtqvIVvOKretfxQG_0OsaiFvb7uFRDu5P8hw/edit#gid=10
|
||||
[4]: https://www.youtube.com/watch?v=NPcMS49V5hg
|
||||
[5]: https://www.cs.ubc.ca/~lowe/papers/ijcv04.pdf
|
||||
@ -0,0 +1,101 @@
|
||||
如何在 Ubuntu Linux 16.04上安装开源的Discourse论坛
|
||||
===============================================================================
|
||||
|
||||
Discourse 是一个开源的论坛, 它可以以邮件列表, 聊天室或者论坛等多种形式工作. 它是一个广受欢迎的现代的论坛工具. 在服务端,它使用Ruby on Rails 和 Postgres 搭建, 并且使用Redis caching 减少读取时间 , 在客户端, 它用浏览器的Java Script运行. 它是一个非常好的定制和构架工具. 并且它提供了转换插件对你现存的论坛进行转换例如: vBulletin, phpBB, Drupal, SMF 等等. 在这篇文章中, 我们将学习在Ubuntu操作系统下安装 Discourse.
|
||||
|
||||
它是基于安全开发的, 黑客们不能轻易的发现漏洞. 它能很好的支持各个平台, 相应的调整手机和平板的显示设置.
|
||||
|
||||
### Installing Discourse on Ubuntu 16.04
|
||||
|
||||
让我们开始吧 ! 最少需要1G的内存并且你要保证dockers已经安装了. 说到dockers, 它还需要安装Git. 要达到以上的两点要求我们只需要运行下面的命令.
|
||||
|
||||
```
|
||||
wget -qO- https://get.docker.com/ | sh
|
||||
```
|
||||
|
||||
|
||||
|
||||
用不了多久就安装好了Docker 和 Git, 安装结束以后, 创建一个 Discourse 文件夹在 /var 分区 (当然你也可以选择其他的分区).
|
||||
|
||||
```
|
||||
mkdir /var/discourse
|
||||
```
|
||||
|
||||
现在我们来克隆 Discourse’s Github 项目到这个新建的文件夹.
|
||||
|
||||
```
|
||||
git clone https://github.com/discourse/discourse_docker.git /var/discourse
|
||||
```
|
||||
|
||||
进入克隆文件夹.
|
||||
|
||||
```
|
||||
cd /var/discourse
|
||||
```
|
||||
|
||||
|
||||
|
||||
你将 看到“discourse-setup” 脚本文件, 运行这个脚本文件进行Discourse的初始化.
|
||||
|
||||
```
|
||||
./discourse-setup
|
||||
```
|
||||
|
||||
**Side note: 在安装discourse之前请确保你已经安装了邮件服务器.**
|
||||
|
||||
安装向导将会问你以下六个问题.
|
||||
|
||||
```
|
||||
Hostname for your Discourse?
|
||||
Email address for admin account?
|
||||
SMTP server address?
|
||||
SMTP user name?
|
||||
SMTP port [587]:
|
||||
SMTP password? []:
|
||||
```
|
||||
|
||||
|
||||
|
||||
当你提交了以上信息以后, 它会让你提交确认, 恩一切都很正常, 点击回车以后安装开始.
|
||||
|
||||
|
||||
|
||||
现在坐下来，倒杯茶，看看有什么错误信息没有.
|
||||
|
||||
|
||||
|
||||
安装成功以后看起来应该像这样.
|
||||
|
||||
|
||||
|
||||
现在打开浏览器, 如果已经做了域名解析, 你可以使用你的域名来连接Discourse页面 , 否则你只能使用IP地址了. 你讲看到如下信息:
|
||||
|
||||
|
||||
|
||||
就是这个, 用 “Sign Up” 选项创建一个新管理账户.
|
||||
|
||||
|
||||
|
||||
### 结论
|
||||
|
||||
它是安装简便安全易用的. 它拥有当前所有论坛功能. 它支持所有的开源产品. 简单, 易用, 各类实用的功能. 希望你喜欢这篇文章你可以给我们留言.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://linuxpitstop.com/install-discourse-on-ubuntu-linux-16-04/
|
||||
|
||||
作者：[Aun][a]
|
||||
译者：[kokialoves](https://github.com/kokialoves)
|
||||
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]: http://linuxpitstop.com/author/aun/
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
193
translated/tech/20160628 Python 101 An Intro to urllib.md
Normal file
193
translated/tech/20160628 Python 101 An Intro to urllib.md
Normal file
@ -0,0 +1,193 @@
|
||||
Python 101: urllib 简介
|
||||
=================================
|
||||
|
||||
Python 3 的 urllib 模块是一堆可以处理 URL 的组件集合。如果你有 Python 2 背景，那么你就会注意到 Python 2 中有 urllib 和 urllib2 两个版本的模块。这些现在都是 Python 3 的 urllib 包的一部分。当前版本的 urllib 包括下面几部分：
|
||||
|
||||
- urllib.request
|
||||
- urllib.error
|
||||
- urllib.parse
|
||||
- urllib.rebotparser
|
||||
|
||||
接下来我们会分开讨论除了 urllib.error 以外的几部分。官方文档实际推荐你尝试第三方库， requests，一个高级的 HTTP 客户端接口。然而我依然认为知道如何不依赖第三方库打开 URL 并与之进行交互是很有用的，而且这也可以帮助你理解为什么 requests 包是如此的流行。
|
||||
|
||||
---
|
||||
|
||||
### urllib.request
|
||||
|
||||
urllib.request 模块期初是用来打开和获取 URL 的。让我们看看你可以用函数 urlopen可以做的事：
|
||||
|
||||
|
||||
```
|
||||
>>> import urllib.request
|
||||
>>> url = urllib.request.urlopen('https://www.google.com/')
|
||||
>>> url.geturl()
|
||||
'https://www.google.com/'
|
||||
>>> url.info()
|
||||
<http.client.HTTPMessage object at 0x7fddc2de04e0>
|
||||
>>> header = url.info()
|
||||
>>> header.as_string()
|
||||
('Date: Fri, 24 Jun 2016 18:21:19 GMT\n'
|
||||
'Expires: -1\n'
|
||||
'Cache-Control: private, max-age=0\n'
|
||||
'Content-Type: text/html; charset=ISO-8859-1\n'
|
||||
'P3P: CP="This is not a P3P policy! See '
|
||||
'https://www.google.com/support/accounts/answer/151657?hl=en for more info."\n'
|
||||
'Server: gws\n'
|
||||
'X-XSS-Protection: 1; mode=block\n'
|
||||
'X-Frame-Options: SAMEORIGIN\n'
|
||||
'Set-Cookie: '
|
||||
'NID=80=tYjmy0JY6flsSVj7DPSSZNOuqdvqKfKHDcHsPIGu3xFv41LvH_Jg6LrUsDgkPrtM2hmZ3j9V76pS4K_cBg7pdwueMQfr0DFzw33SwpGex5qzLkXUvUVPfe9g699Qz4cx9ipcbU3HKwrRYA; '
|
||||
'expires=Sat, 24-Dec-2016 18:21:19 GMT; path=/; domain=.google.com; HttpOnly\n'
|
||||
'Alternate-Protocol: 443:quic\n'
|
||||
'Alt-Svc: quic=":443"; ma=2592000; v="34,33,32,31,30,29,28,27,26,25"\n'
|
||||
'Accept-Ranges: none\n'
|
||||
'Vary: Accept-Encoding\n'
|
||||
'Connection: close\n'
|
||||
'\n')
|
||||
>>> url.getcode()
|
||||
200
|
||||
```
|
||||
|
||||
在这里我们包含了需要的模块，然后告诉它打开 Google 的 URL。现在我们就有了一个可以交互的 HTTPResponse 对象。我们要做的第一件事是调用方法 geturl ，它会返回根据 URL 获取的资源。这可以让我们发现 URL 是否进行了重定向。
|
||||
|
||||
接下来调用 info ，它会返回网页的元数据，比如头信息。因此，我们可以将结果赋给我们的 headers 变量，然后调用它的方法 as_string 。就可以打印出我们从 Google 收到的头信息。你也可以通过 getcode 得到网页的 HTTP 响应码，当前情况下就是 200，意思是正常工作。
|
||||
|
||||
如果你想看看网页的 HTML 代码，你可以调用变量 url 的方法 read。我不准备再现这个过程，因为输出结果太长了。
|
||||
|
||||
请注意 request 对象默认是 GET 请求，除非你指定它的 data 参数。你应该给它传递 data 参数，这样 request 对象才会变成 POST 请求。
|
||||
|
||||
---
|
||||
|
||||
### 下载文件
|
||||
|
||||
urllib 一个典型的应用场景是下载文件。让我们看看几种可以完成这个任务的方法：
|
||||
|
||||
```
|
||||
>>> import urllib.request
|
||||
>>> url = 'http://www.blog.pythonlibrary.org/wp-content/uploads/2012/06/wxDbViewer.zip'
|
||||
>>> response = urllib.request.urlopen(url)
|
||||
>>> data = response.read()
|
||||
>>> with open('/home/mike/Desktop/test.zip', 'wb') as fobj:
|
||||
... fobj.write(data)
|
||||
...
|
||||
```
|
||||
|
||||
这个例子中我们打开一个保存在我的博客上的 zip 压缩文件的 URL。然后我们读出数据并将数据写到磁盘。一个替代方法是使用 urlretrieve ：
|
||||
|
||||
```
|
||||
>>> import urllib.request
|
||||
>>> url = 'http://www.blog.pythonlibrary.org/wp-content/uploads/2012/06/wxDbViewer.zip'
|
||||
>>> tmp_file, header = urllib.request.urlretrieve(url)
|
||||
>>> with open('/home/mike/Desktop/test.zip', 'wb') as fobj:
|
||||
... with open(tmp_file, 'rb') as tmp:
|
||||
... fobj.write(tmp.read())
|
||||
```
|
||||
|
||||
方法 urlretrieve 会把网络对象拷贝到本地文件。除非你在使用 urlretrieve 的第二个参数指定你要保存文件的路径，否则这个文件在本地是随机命名的并且是保存在临时文件夹。这个可以为你节省一步操作，并且使代码开起来更简单：
|
||||
|
||||
```
|
||||
>>> import urllib.request
|
||||
>>> url = 'http://www.blog.pythonlibrary.org/wp-content/uploads/2012/06/wxDbViewer.zip'
|
||||
>>> urllib.request.urlretrieve(url, '/home/mike/Desktop/blog.zip')
|
||||
('/home/mike/Desktop/blog.zip',
|
||||
<http.client.HTTPMessage object at 0x7fddc21c2470>)
|
||||
```
|
||||
|
||||
如你所见，它返回了文件保存的路径，以及从请求得来的头信息。
|
||||
|
||||
### 设置你的用户代理
|
||||
|
||||
当你使用浏览器访问网页时，浏览器会告诉网站它是谁。这就是所谓的 user-agent 字段。Python 的 urllib 会表示他自己为 Python-urllib/x.y ， 其中 x 和 y 是你使用的 Python 的主、次版本号。有一些网站不认识这个用户代理字段，然后网站的可能会有奇怪的表现或者根本不能正常工作。辛运的是你可以很轻松的设置你自己的 user-agent 字段。
|
||||
|
||||
```
|
||||
>>> import urllib.request
|
||||
>>> user_agent = ' Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0'
|
||||
>>> url = 'http://www.whatsmyua.com/'
|
||||
>>> headers = {'User-Agent': user_agent}
|
||||
>>> request = urllib.request.Request(url, headers=headers)
|
||||
>>> with urllib.request.urlopen(request) as response:
|
||||
... with open('/home/mdriscoll/Desktop/user_agent.html', 'wb') as out:
|
||||
... out.write(response.read())
|
||||
```
|
||||
|
||||
这里设置我们的用户代理为 Mozilla FireFox ，然后我们访问 <http://www.whatsmyua.com/> ， 它会告诉我们它识别出的我们的 user-agent 字段。之后我们将 url 和我们的头信息传给 urlopen 创建一个 Request 实例。最后我们保存这个结果。如果你打开这个结果，你会看到我们成功的修改了自己的 user-agent 字段。使用这段代码尽情的尝试不同的值来看看它是如何改变的。
|
||||
|
||||
---
|
||||
|
||||
### urllib.parse
|
||||
|
||||
urllib.parse 库是用来拆分和组合 URL 字符串的标准接口。比如，你可以使用它来转换一个相对的 URL 为绝对的 URL。让我们试试用它来转换一个包含查询的 URL ：
|
||||
|
||||
|
||||
```
|
||||
>>> from urllib.parse import urlparse
|
||||
>>> result = urlparse('https://duckduckgo.com/?q=python+stubbing&t=canonical&ia=qa')
|
||||
>>> result
|
||||
ParseResult(scheme='https', netloc='duckduckgo.com', path='/', params='', query='q=python+stubbing&t=canonical&ia=qa', fragment='')
|
||||
>>> result.netloc
|
||||
'duckduckgo.com'
|
||||
>>> result.geturl()
|
||||
'https://duckduckgo.com/?q=python+stubbing&t=canonical&ia=qa'
|
||||
>>> result.port
|
||||
None
|
||||
```
|
||||
|
||||
这里我们导入了函数 urlparse ， 并且把一个包含搜索查询 duckduckgo 的 URL 作为参数传给它。我的查询的关于 “python stubbing” 的文章。如你所见，它返回了一个 ParseResult 对象，你可以用这个对象了解更多关于 URL 的信息。举个例子，你可以获取到短信息（此处的没有端口信息），网络位置，路径和很多其他东西。
|
||||
|
||||
### 提交一个 Web 表单
|
||||
|
||||
这个模块还有一个方法 urlencode 可以向 URL 传输数据。 urllib.parse 的一个典型使用场景是提交 Web 表单。让我们通过搜索引擎 duckduckgo 搜索 Python 来看看这个功能是怎么工作的。
|
||||
|
||||
```
|
||||
>>> import urllib.request
|
||||
>>> import urllib.parse
|
||||
>>> data = urllib.parse.urlencode({'q': 'Python'})
|
||||
>>> data
|
||||
'q=Python'
|
||||
>>> url = 'http://duckduckgo.com/html/'
|
||||
>>> full_url = url + '?' + data
|
||||
>>> response = urllib.request.urlopen(full_url)
|
||||
>>> with open('/home/mike/Desktop/results.html', 'wb') as f:
|
||||
... f.write(response.read())
|
||||
```
|
||||
|
||||
这个例子很直接。基本上我们想使用 Python 而不是浏览器向 duckduckgo 提交一个查询。要完成这个我们需要使用 urlencode 构建我们的查询字符串。然后我们把这个字符串和网址拼接成一个完整的正确 URL ，然后使用 urllib.request 提交这个表单。最后我们就获取到了结果然后保存到磁盘上。
|
||||
|
||||
---
|
||||
|
||||
### urllib.robotparser
|
||||
|
||||
robotparser 模块是由一个单独的类 —— RobotFileParser —— 构成的。这个类会回答诸如一个特定的用户代理可以获取已经设置 robot.txt 的网站。 robot.txt 文件会告诉网络爬虫或者机器人当前网站的那些部分是不允许被访问的。让我们看一个简单的例子：
|
||||
|
||||
```
|
||||
>>> import urllib.robotparser
|
||||
>>> robot = urllib.robotparser.RobotFileParser()
|
||||
>>> robot.set_url('http://arstechnica.com/robots.txt')
|
||||
None
|
||||
>>> robot.read()
|
||||
None
|
||||
>>> robot.can_fetch('*', 'http://arstechnica.com/')
|
||||
True
|
||||
>>> robot.can_fetch('*', 'http://arstechnica.com/cgi-bin/')
|
||||
False
|
||||
```
|
||||
|
||||
这里我们导入了 robot 分析器类，然后创建一个实例。然后我们给它传递一个表明网站 robots.txt 位置的 URL 。接下来我们告诉分析器来读取这个文件。现在就完成了，我们给它了一组不同的 URL 让它找出那些我们可以爬取而那些不能爬取。我们很快就看到我们可以访问主站但是不包括 cgi-bin 路径。
|
||||
|
||||
---
|
||||
|
||||
### 总结一下
|
||||
|
||||
现在你就有能力使用 Python 的 urllib 包了。在这一节里，我们学习了如何下载文件，提交 Web 表单，修改自己的用户代理以及访问 robots.txt。 urllib 还有一大堆附加功能没有在这里提及，比如网站授权。然后你可能会考虑在使用 urllib 进行认证之前切换到 requests 库，因为 requests 已经以更易用和易调试的方式实现了这些功能。我同时也希望提醒你 Python 已经通过 http.cookies 模块支持 Cookies 了，虽然在 request 包里也很好的封装了这个功能。你应该可能考虑同时试试两个来决定那个最适合你。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.blog.pythonlibrary.org/2016/06/28/python-101-an-intro-to-urllib/
|
||||
|
||||
作者：[Mike][a]
|
||||
译者：[Ezio](https://github.com/oska874)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: http://www.blog.pythonlibrary.org/author/mld/
|
||||
@ -0,0 +1,100 @@
|
||||
用 VeraCrypt 加密闪存盘
|
||||
============================================
|
||||
|
||||
很多安全专家偏好像 VeraCrypt 这类能够用来加密闪存盘的开源软件。因为获取它的源代码很简单。
|
||||
|
||||
保护 USB闪存盘里的数据，加密是一个聪明的方法，正如我们在使用 Microsoft 的 BitLocker [加密闪存盘][1] 一文中提到的。
|
||||
|
||||
但是如果你不想用 BitLocker 呢？
|
||||
|
||||
你可能有顾虑，因为你不能够查看 Microsoft 的程序源码，那么它容易被植入用于政府或其它用途的“后门”。由于开源软件的源码是公开的，很多安全专家认为开源软件很少藏有后门。
|
||||
|
||||
还好，有几个开源加密软件能作为 BitLocker 的替代。
|
||||
|
||||
要是你需要在 Windows 系统，苹果的 OS X 系统或者 Linux 系统上加密以及访问文件，开源软件 [VeraCrypt][2] 提供绝佳的选择。
|
||||
|
||||
VeraCrypt 源于 TrueCrypt。TrueCrypt是一个备受好评的开源加密软件，尽管它现在已经停止维护了。但是 TrueCrypt 的代码通过了审核，没有发现什么重要的安全漏洞。另外，它已经在 VeraCrypt 中进行了改善。
|
||||
|
||||
Windows，OS X 和 Linux 系统的版本都有。
|
||||
|
||||
用 VeraCrypt 加密 USB 闪存盘不像用 BitLocker 那么简单，但是它只要几分钟就好了。
|
||||
|
||||
### 用 VeraCrypt 加密闪存盘的 8 个步骤
|
||||
|
||||
对应操作系统 [下载 VeraCrypt][3] 之后：
|
||||
|
||||
打开 VeraCrypt，点击 Create Volume，进入 VeraCrypt 的创建卷的向导程序（VeraCrypt Volume Creation Wizard）。（注：VeraCrypt Volume Creation Wizard 首字母全大写，不清楚是否需要翻译，之后有很多首字母大写的词，都以括号标出）
|
||||
|
||||
|
||||
|
||||
VeraCrypt 创建卷向导（VeraCrypt Volume Creation Wizard）允许你在闪存盘里新建一个加密文件容器，这与其它未加密文件是独立的。或者你也可以选择加密整个闪存盘。这个时候你就选加密整个闪存盘就行。
|
||||
|
||||
|
||||
|
||||
然后选择标准模式（Standard VeraCrypt Volume）。
|
||||
|
||||
|
||||
|
||||
选择你想加密的闪存盘的驱动器卷标（这里是 O：）。
|
||||
|
||||
|
||||
|
||||
选择创建卷标模式（Volume Creation Mode）。如果你的闪存盘是空的，或者你想要删除它里面的所有东西，选第一个。要么你想保持所有现存的文件，选第二个就好了。
|
||||
|
||||
|
||||
|
||||
这一步允许你选择加密选项。要是你不确定选哪个，就用默认的 AES 和 SHA-512 设置。
|
||||
|
||||
|
||||
|
||||
确定了卷标容量后，输入并确认你想要用来加密数据密码。
|
||||
|
||||
|
||||
|
||||
要有效工作，VeraCrypt 要从一个熵或者“随机数”池中取出一个随机数。要初始化这个池，你将被要求随机地移动鼠标一分钟。一旦进度条变绿了，或者更方便的是等到进度条到了屏幕右边足够远的时候，点击 “Format” 来结束创建加密盘。
|
||||
|
||||
|
||||
|
||||
### 用 VeraCrypt 使用加密过的闪存盘
|
||||
|
||||
当你想要使用一个加密了的闪存盘，先插入闪存盘到电脑上，启动 VeraCrypt。
|
||||
|
||||
然后选择一个没有用过的卷标（比如 z:），点击自动挂载设备（Auto-Mount Devices）。
|
||||
|
||||
|
||||
|
||||
输入密码，点击确定。
|
||||
|
||||
|
||||
|
||||
挂载过程需要几分钟，这之后你的解密盘就能通过你先前选择的盘符进行访问了。
|
||||
|
||||
### VeraCrypt 移动硬盘安装步骤
|
||||
|
||||
如果你设置闪存盘的时候，选择的是加密过的容器而不是加密整个盘，你可以选择创建 VeraCrypt 称为移动盘（Traveler Disk）的设备。这会复制安装一个 VeraCrypt 在 USB 闪存盘。当你在别的 Windows 电脑上插入 U 盘时，就能从 U 盘自动运行 VeraCrypt；也就是说没必要在新电脑上安装 VeraCrypt。
|
||||
|
||||
你可以设置闪存盘作为一个移动硬盘（Traveler Disk），在 VeraCrypt 的工具栏（Tools）菜单里选择 Traveler Disk SetUp 就行了。
|
||||
|
||||
|
||||
|
||||
要从移动盘（Traveler Disk）上运行 VeraCrypt，你必须要有那台电脑的管理员权限，这不足为奇。尽管这看起来是个限制，机密文件无法在不受控制的电脑上安全打开，比如在一个商务中心的电脑上。
|
||||
|
||||
>Paul Rubens 从事技术行业已经超过 20 年。这期间他为英国和国际主要的出版社，包括 《The Economist》《The Times》《Financial Times》《The BBC》《Computing》和《ServerWatch》等出版社写过文章，
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.esecurityplanet.com/open-source-security/how-to-encrypt-flash-drive-using-veracrypt.html
|
||||
|
||||
作者：[Paul Rubens ][a]
|
||||
译者：[GitFuture](https://github.com/GitFuture)
|
||||
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]: http://www.esecurityplanet.com/author/3700/Paul-Rubens
|
||||
[1]: http://www.esecurityplanet.com/views/article.php/3880616/How-to-Encrypt-a-USB-Flash-Drive.htm
|
||||
[2]: http://www.esecurityplanet.com/open-source-security/veracrypt-a-worthy-truecrypt-alternative.html
|
||||
[3]: https://veracrypt.codeplex.com/releases/view/619351
|
||||
|
||||
|
||||
|
||||
@ -1,7 +1,7 @@
|
||||
使用 Python 创建你自己的 Shell:Part II
|
||||
===========================================
|
||||
|
||||
在[part 1][1] 中，我们已经创建了一个主要的 shell 循环、切分了的命令输入，以及通过 `fork` 和 `exec` 执行命令。在这部分，我们将会解决剩下的问题。首先，`cd test_dir2` 命令无法修改我们的当前目录。其次，我们仍无法优雅地从 shell 中退出。
|
||||
在 [part 1][1] 中，我们已经创建了一个主要的 shell 循环、切分了的命令输入，以及通过 `fork` 和 `exec` 执行命令。在这部分，我们将会解决剩下的问题。首先，`cd test_dir2` 命令无法修改我们的当前目录。其次，我们仍无法优雅地从 shell 中退出。
|
||||
|
||||
### 步骤 4：内置命令
|
||||
|
||||
|
||||
@ -0,0 +1,95 @@
|
||||
在用户空间做我们会在内核空间做的事情
|
||||
=======================================================
|
||||
|
||||
我相信，Linux 最好也是最坏的事情，就是内核空间和用户空间之间的巨大差别。
|
||||
|
||||
但是如果抛开这个区别，Linux 可能也不会成为世界上影响力最大的操作系统。如今，Linux 已经拥有世界上最大数量的用户，和最大范围的应用。尽管大多数用户并不知道，当他们进行谷歌搜索，或者触摸安卓手机的时候，他们其实正在使用 Linux。如果不是 Linux 的巨大成功，Apple 公司也可能并不会成为现在这样（苹果在他们的电脑产品中使用 BSD 发行版）。
|
||||
|
||||
不用担心，用户空间是 Linux 内核开发中的一个特性，并不是一个缺陷。正如 Linus 在 2003 的极客巡航中提到的那样，“”我只做内核相关技术……我并不知道内核之外发生的事情，而且我并不关心。我只关注内核部分发生的事情。” 在 Andrew Morton 在多年之后的另一个极客巡航上给我上了另外的一课，我写到：
|
||||
|
||||
> 内核空间是 Linux 核心存在的地方。用户空间是使用 Linux 时使用的空间，和其他的自然的建筑材料一样。内核空间和用户空间的区别，和自然材料和人类从中生产的人造材料的区别很类似。
|
||||
|
||||
这个区别的自然而然的结果，就是尽管外面的世界一刻也离不开 Linux， 但是 Linux 社区还是保持相对较小。所以，为了增加我们社区团体的数量，我希望指出两件事情。第一件已经非常火热，另外一件可能热门。
|
||||
|
||||
第一件事情就是 [blockchain][1]，出自著名的分布式货币，比特币之手。当你正在阅读这篇文章的同时，对 blockchain 的[兴趣已经直线上升][2]。
|
||||
|
||||
|
||||
> 图1. 谷歌 Blockchain 的趋势
|
||||
|
||||
第二件事就是自主身份。为了解释这个，让我先来问你，你是谁或者你是什么。
|
||||
|
||||
如果你从你的雇员，你的医生，或者车管所，Facebook，Twitter 或者谷歌上得到答案，你就会发现他们每一个都有明显的社会性： 为了他们自己的便利，在进入这些机构的控制前，他们都会添加自己的命名空间。正如 Timothy Ruff 在 [Evernym][3] 中解释的，”你并不为了他们而存在，你只为了自己的身份而活。“。你的身份可能会变化，但是唯一不变的就是控制着身份的人，也就是这个组织。
|
||||
|
||||
如果你的答案出自你自己，我们就有一个广大空间来发展一个新的领域，在这个领域中，我们完全自由。
|
||||
|
||||
第一个解释这个的人，据我所知，是 [Devon Loffreto][4]。在 2012 年 2 月，在的他的博客中，他写道 ”什么是' Sovereign Source Authority'？“，[Moxy Tongue][5]。在他发表在 2016 年 2 月的 "[Self-Sovereign Identity][6]" 中，他写道：
|
||||
|
||||
> 自主身份必须是独立个人提出的，并且不包含社会因素。。。自主身份源于每个个体对其自身本源的认识。 一个自主身份可以为个体带来新的社会面貌。每个个体都可能为自己生成一个自主身份，并且这并不会改变固有的人权。使用自主身份机制是所有参与者参与的基石，并且 依旧可以同各种形式的人类社会保持联系。
|
||||
|
||||
为了将这个发布在 Linux 条款中，只有个人才能为他或她设定一个自己的开源社区身份。这在现实实践中，这只是一个非常偶然的事件。举个例子，我自己的身份包括：
|
||||
|
||||
- David Allen Searls，我父母会这样叫我。
|
||||
- David Searls，正式场合下我会这么称呼自己。
|
||||
- Dave，我的亲戚和好朋友会这么叫我。
|
||||
- Doc，大多数人会这么叫我。
|
||||
|
||||
在上述提到的身份认证中，我可以在不同的情景中轻易的转换。但是，这只是在现实世界中。在虚拟世界中，这就变得非常困难。除了上述的身份之外，我还可以是 @dsearls(我的 twitter 账号) 和 dsearls (其他的网络账号)。然而为了记住成百上千的不同账号的登录名和密码，我已经不堪重负。
|
||||
|
||||
你可以在你的浏览器上感受到这个糟糕的体验。在火狐上，我有成百上千个用户名密码。很多已经废弃(很多都是从 Netscape 时代遗留下来的)，但是我依旧假设我有时会有大量的工作账号需要处理。对于这些，我只是被动接受者。没有其他的解决方法。甚至一些安全较低的用户认证，已经成为了现实世界中不可缺少的一环。
|
||||
|
||||
现在，最简单的方式来联系账号，就是通过 "Log in with Facebook" 或者 "Login in with Twitter" 来进行身份认证。在这些例子中，我们中的每一个甚至并不是真正意义上的自己，或者某种程度上是我们希望被大家认识的自己（如果我们希望被其他人认识的话）。
|
||||
|
||||
我们从一开始就需要的是一个可以实体化我们的自主身份和交流时选择如何保护和展示自身的个人系统。因为缺少这个能力，我们现在陷入混乱。Shoshana Zuboff 称之为 "监视资本主义"，她如此说道：
|
||||
|
||||
>...难以想象，在见证了互联网和获得了的巨大成功的谷歌背后。世界因 Apple 和 FBI 的对决而紧密联系在一起。真相就是，被热衷于监视的资本家开发监视系统，是每一个国家安全机构真正的恶。
|
||||
|
||||
然后，她问道，”我们怎样才能保护自己远离他人的影响？“
|
||||
|
||||
我建议使用自主身份。我相信这是我们唯一的方式，来保证我们从一个被监视的世界中脱离出来。以此为基础，我们才可以完全无顾忌的和社会，政治，商业上的人交流。
|
||||
|
||||
我在五月联合国举行的 [ID2020][7] 会议中总结了这个临时的结论。很高兴，Devon Loffreto 也在那，自从他在2013年被选为作为轮值主席之后。这就是[我曾经写的一些文章][8]，引用了 Devon 的早期博客(比如上面的原文)。
|
||||
|
||||
这有三篇这个领域的准则:
|
||||
|
||||
- "[Self-Sovereign Identity][9]" - Devon Loffreto.
|
||||
- "[System or Human First][10]" - Devon Loffreto.
|
||||
- "[The Path to Self-Sovereign Identity][11]" - Christopher Allen.
|
||||
|
||||
从Evernym 的简要说明中，[digi.me][12], [iRespond][13] 和 [Respect Network][14] 也被包括在内。自主身份和社会身份 (也被称为”current model“） 的对比结果，显示在图二中。
|
||||
|
||||
|
||||
> 图 2. Current Model 身份 vs. 自主身份
|
||||
|
||||
为此而生的[平台][15]就是 Sovrin，也被解释为“”依托于先进技术的，授权机制的，分布式货币上的一个完全开源，基于标识，声明身份的图平台“ 同时，这也有一本[白皮书][16]。代号为 [plenum][17]，而且它在 Github 上。
|
||||
|
||||
在这-或者其他类似的地方-我们就可以在用户空间中重现我们在上一个的四分之一世纪中已经做过的事情。
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linuxjournal.com/content/doing-user-space-what-we-did-kernel-space
|
||||
|
||||
作者：[Doc Searls][a]
|
||||
译者：[译者ID](https://github.com/MikeCoder)
|
||||
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.linuxjournal.com/users/doc-searls
|
||||
[1]: https://en.wikipedia.org/wiki/Block_chain_%28database%29
|
||||
[2]: https://www.google.com/trends/explore#q=blockchain
|
||||
[3]: http://evernym.com/
|
||||
[4]: https://twitter.com/nzn
|
||||
[5]: http://www.moxytongue.com/2012/02/what-is-sovereign-source-authority.html
|
||||
[6]: http://www.moxytongue.com/2016/02/self-sovereign-identity.html
|
||||
[7]: http://www.id2020.org/
|
||||
[8]: http://blogs.harvard.edu/doc/2013/10/14/iiw-challenge-1-sovereign-identity-in-the-great-silo-forest
|
||||
[9]: http://www.moxytongue.com/2016/02/self-sovereign-identity.html
|
||||
[10]: http://www.moxytongue.com/2016/05/system-or-human.html
|
||||
[11]: http://www.lifewithalacrity.com/2016/04/the-path-to-self-soverereign-identity.html
|
||||
[12]: https://get.digi.me/
|
||||
[13]: http://irespond.com/
|
||||
[14]: https://www.respectnetwork.com/
|
||||
[15]: http://evernym.com/technology
|
||||
[16]: http://evernym.com/assets/doc/Identity-System-Essentials.pdf?v=167284fd65
|
||||
[17]: https://github.com/evernym/plenum
|
||||
130
translated/tech/20160711 Getting started with Git.md
Normal file
130
translated/tech/20160711 Getting started with Git.md
Normal file
@ -0,0 +1,130 @@
|
||||
初步了解 Git
|
||||
=========================
|
||||
|
||||
|
||||
> 图片来源：opensource.com
|
||||
|
||||
在这个系列的介绍中，我们学习到了谁应该使用 Git，以及 Git 是用来做什么的。今天，我们将学习如何克隆公共的 Git 仓库，以及如何提取出独立的文件而不用克隆整个仓库。
|
||||
|
||||
由于 Git 如此流行，因而如果你能够至少熟悉一些基础的 Git 知识也能为你的生活带来很多便捷。如果你可以掌握 Git 基础（你可以的，我发誓！），那么你将能够下载任何你需要的东西，甚至还可能做一些贡献作为回馈。毕竟，那就是开源的精髓所在：你拥有获取你使用的软件代码的权利，拥有和他人分享的自由，以及只要你愿意就可以修改它的权利。只要你熟悉了 Git，它就可以让这一切都变得很容易。
|
||||
|
||||
那么，让我们一起来熟悉 Git 吧。
|
||||
|
||||
### 读和写
|
||||
一般来说，有两种方法可以和 Git 仓库交互：你可以从仓库中读取，或者你也能够向仓库中写入。它就像一个文件：有时候你打开一个文档只是为了阅读它，而其它时候你打开文档是因为你需要做些改动。
|
||||
|
||||
本文仅讲解如何从 Git 仓库读取。我们将会在后面的一篇文章中讲解如何向 Git 仓库写回的主题。
|
||||
|
||||
### Git 还是 GitHub？
|
||||
一句话澄清：Git 不同于 GitHub（或 GitLab，或 Bitbucket）。Git 是一个命令行程序，所以它就像下面这样：
|
||||
|
||||
```
|
||||
$ git
|
||||
usage: Git [--version] [--help] [-C <path>]
|
||||
[-p | --paginate | --no-pager] [--bare]
|
||||
[--Git-dir=<path>] <command> [<args>]
|
||||
|
||||
```
|
||||
|
||||
由于 Git 是开源的，所以就有许多聪明人围绕它构建了基础软件；这些基础软件，包括在他们自己身边，都已经变得非常流行了。
|
||||
|
||||
我的文章系列将首先教你纯粹的 Git 知识，因为一旦你理解了 Git 在做什么，那么你就无需关心正在使用的前端工具是什么了。然而，我的文章系列也将涵盖通过流行的 Git 服务完成每项任务的常用方法，因为那些将可能是你首先会遇到的。
|
||||
|
||||
### 安装 Git
|
||||
在 Linux 系统上，你可以从所使用的发行版软件仓库中获取并安装 Git。BSD 用户应当在 Ports 树的 devel 部分查找 Git。
|
||||
|
||||
对于闭源的操作系统，请前往 [项目网站][1] 并根据说明安装。一旦安装后，在 Linux、BSD 和 Mac OS X 上的命令应当没有任何差别。Windows 用户需要调整 Git 命令，从而和 Windows 文件系统相匹配，或者安装 Cygwin 以原生的方式运行 Git，而不受 Windows 文件系统转换问题的羁绊。
|
||||
|
||||
### 下午茶和 Git
|
||||
并非每个人都需要立刻将 Git 加入到我们的日常生活中。有些时候，你和 Git 最多的交互就是访问一个代码库，下载一两个文件，然后就不用它了。以这样的方式看待 Git，它更像是下午茶而非一次正式的宴会。你进行一些礼节性的交谈，获得了需要的信息，然后你就会离开，至少接下来的三个月你不再想这样说话。
|
||||
|
||||
当然，那是可以的。
|
||||
|
||||
一般来说，有两种方法访问 Git：使用命令行，或者使用一种神奇的因特网技术通过 web 浏览器快速轻松地访问。
|
||||
|
||||
假设你想要在终端中安装并使用一个回收站，因为你已经被 rm 命令毁掉太多次了。你已经听说过 Trashy 了，它称自己为「理智的 rm 命令媒介」，并且你想在安装它之前阅读它的文档。幸运的是，[Trashy 公开地托管在 GitLab.com][2]。
|
||||
|
||||
### Landgrab
|
||||
我们工作的第一步是对这个 Git 仓库使用 landgrab 排序方法：我们会克隆这个完整的仓库，然后会根据内容排序。由于该仓库是托管在公共的 Git 服务平台上，所以有两种方式来完成工作：使用命令行，或者使用 web 界面。
|
||||
|
||||
要想使用 Git 获取整个仓库，就要使用 git clone 命令和 Git 仓库的 URL 作为参数。如果你不清楚正确的 URL 是什么，仓库应该会告诉你的。GitLab 为你提供了 [Trashy][3] 仓库的拷贝-粘贴 URL。
|
||||
|
||||
|
||||
|
||||
你也许注意到了，在某些服务平台上，会同时提供 SSH 和 HTTPS 链接。只有当你拥有仓库的写权限时，你才可以使用 SSH。否则的话，你必须使用 HTTPS URL。
|
||||
|
||||
一旦你获得了正确的 URL，克隆仓库是非常容易的。就是 git clone 这个 URL 即可，可选项是可以指定要克隆到的目录。默认情况下会将 git 目录克隆到你当前所在的位置；例如，'trashy.git' 表示将仓库克隆到你当前位置的 'trashy' 目录。我使用 .clone 扩展名标记那些只读的仓库，使用 .git 扩展名标记那些我可以读写的仓库，但那无论如何也不是官方要求的。
|
||||
|
||||
```
|
||||
$ git clone https://gitlab.com/trashy/trashy.git trashy.clone
|
||||
Cloning into 'trashy.clone'...
|
||||
remote: Counting objects: 142, done.
|
||||
remote: Compressing objects: 100% (91/91), done.
|
||||
remote: Total 142 (delta 70), reused 103 (delta 47)
|
||||
Receiving objects: 100% (142/142), 25.99 KiB | 0 bytes/s, done.
|
||||
Resolving deltas: 100% (70/70), done.
|
||||
Checking connectivity... done.
|
||||
```
|
||||
|
||||
一旦成功地克隆了仓库，你就可以像对待你电脑上任何其它目录那样浏览仓库中的文件。
|
||||
|
||||
另外一种获得仓库拷贝的方式是使用 web 界面。GitLab 和 GitHub 都会提供一个 .zip 格式的仓库快照文件。GitHub 有一个大的绿色下载按钮，但是在 GitLab 中，可以浏览器的右侧找到并不显眼的下载按钮。
|
||||
|
||||
|
||||
|
||||
### 仔细挑选
|
||||
另外一种从 Git 仓库中获取文件的方法是找到你想要的文件，然后把它从仓库中拽出来。只有 web 界面才提供这种方法，本质上来说，你看到的是别人仓库的克隆；你可以把它想象成一个 HTTP 共享目录。
|
||||
|
||||
使用这种方法的问题是，你也许会发现某些文件并不存在于原始仓库中，因为完整形式的文件可能只有在执行 make 命令后才能构建，那只有你下载了完整的仓库，阅读了 README 或者 INSTALL 文件，然后运行相关命令之后才会产生。不过，假如你确信文件存在，而你只想进入仓库，获取那个文件，然后离开的话，你就可以那样做。
|
||||
|
||||
在 GitLab 和 GitHub 中，单击文件链接，并在 Raw 模式下查看，然后使用你的 web 浏览器的保存功能，例如：在 Firefox 中，文件 > 保存页面为。在一个 GitWeb 仓库中（一些更喜欢自己托管 git 的人使用的私有 git 仓库 web 查看器），Raw 查看链接在文件列表视图中。
|
||||
|
||||
|
||||
|
||||
### 最佳实践
|
||||
通常认为，和 Git 交互的正确方式是克隆完整的 Git 仓库。这样认为是有几个原因的。首先，可以使用 git pull 命令轻松地使克隆仓库保持更新，这样你就不必在每次文件改变时就重回 web 站点获得一份全新的拷贝。第二，你碰巧需要做些改进，只要保持仓库整洁，那么你可以非常轻松地向原来的作者提交所做的变更。
|
||||
|
||||
现在，可能是时候练习查找感兴趣的 Git 仓库，然后将它们克隆到你的硬盘中了。只要你了解使用终端的基础知识，那就不会太难做到。还不知道终端使用基础吗？那再给多我 5 分钟时间吧。
|
||||
|
||||
### 终端使用基础
|
||||
首先要知道的是，所有的文件都有一个路径。这是有道理的；如果我让你在常规的非终端环境下为我打开一个文件，你就要导航到文件在你硬盘的位置，并且直到你找到那个文件，你要浏览一大堆窗口。例如，你也许要点击你的家目录 > 图片 > InktoberSketches > monkey.kra。
|
||||
|
||||
在那样的场景下，我们可以说文件 monkeysketch.kra 的路径是：$HOME/图片/InktoberSketches/monkey.kra。
|
||||
|
||||
在终端中，除非你正在处理一些特殊的系统管理员任务，你的文件路径通常是以 $HOME 开头的（或者，如果你很懒，就使用 ~ 字符），后面紧跟着一些列的文件夹直到文件名自身。
|
||||
这就和你在 GUI 中点击各种图标直到找到相关的文件或文件夹类似。
|
||||
|
||||
如果你想把 Git 仓库克隆到你的文档目录，那么你可以打开一个终端然后运行下面的命令：
|
||||
|
||||
```
|
||||
$ git clone https://gitlab.com/foo/bar.git
|
||||
$HOME/文档/bar.clone
|
||||
```
|
||||
一旦克隆完成，你可以打开一个文件管理器窗口，导航到你的文档文件夹，然后你就会发现 bar.clone 目录正在等待着你访问。
|
||||
|
||||
如果你想要更高级点，你或许会在以后再次访问那个仓库，可以尝试使用 git pull 命令来查看项目有没有更新：
|
||||
|
||||
```
|
||||
$ cd $HOME/文档/bar.clone
|
||||
$ pwd
|
||||
bar.clone
|
||||
$ git pull
|
||||
```
|
||||
|
||||
到目前为止，你需要初步了解的所有终端命令就是那些了，那就去探索吧。你实践得越多，Git 掌握得就越好（孰能生巧），那就是游戏的名称，至少给了或取了一个元音。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/7/stumbling-git
|
||||
|
||||
作者：[Seth Kenlon][a]
|
||||
译者：[ChrisLeeGit](https://github.com/chrisleegit)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/seth
|
||||
[1]: https://git-scm.com/download
|
||||
[2]: https://gitlab.com/trashy/trashy
|
||||
[3]: https://gitlab.com/trashy/trashy.git
|
||||
|
||||
199
translated/tech/20160718 Creating your first Git repository.md
Normal file
199
translated/tech/20160718 Creating your first Git repository.md
Normal file
@ -0,0 +1,199 @@
|
||||
|
||||
|
||||
建立你的第一个仓库
|
||||
======================================
|
||||
|
||||
|
||||
|
||||
|
||||
现在是时候学习怎样创建你自己的仓库了，还有怎样增加文件和完成提交。
|
||||
|
||||
在本系列前面文章的安装过程中，你已经学习了作为一个目标用户怎样与 Git 进行交互；你就像一个漫无目的的流浪者一样偶然发现了一个开源项目网站，然后克隆了仓库，Git 走进了你的生活。学习怎样和 Git 进行交互并不像你想的那样困难，或许你并不确信现在是否应该使用 Git 完成你的工作。
|
||||
|
||||
|
||||
Git 被认为是选择大多软件项目的工具，它不仅能够完成大多软件项目的工作；它也能管理你杂乱项目的列表（如果他们不重要，也可以这样说！），你的配置文件，一个日记，项目进展日志，甚至源代码！
|
||||
|
||||
使用 Git 是很有必要的，毕竟，你肯定有因为一个备份文件不能够辨认出版本信息而烦恼的时候。
|
||||
|
||||
你不使用 Git，它也就不会为你工作，或者也可以把 Git 理解为“没有任何推送就像源头指针一样”【译注： HEAD 可以理解为“头指针”，是当前工作区的“基础版本”，当执行提交时， HEAD 指向的提交将作为新提交的父提交。】。我保证，你很快就会对 Git 有所了解 。
|
||||
|
||||
|
||||
### 类比于录音
|
||||
|
||||
|
||||
我们更喜欢谈论快照上的图像，因为很多人都可以通过一个相册很快辨认出每个照片上特有的信息。这可能很有用，然而，我认为 Git 更像是在进行声音的记录。
|
||||
|
||||
传统的录音机，可能你对于它的部件不是很清楚：它包含转轴并且正转或反转，使用磁带保存声音波形，通过放音头记录声音并保存到磁带上然后播放给收听者。
|
||||
|
||||
|
||||
除了往前退磁带，你也可以把磁带多绕几圈到磁带前面的部分，或快进跳过前面的部分到最后。
|
||||
|
||||
想象一下 70 年代的磁带录制的声音。你可能想到那会正在反复练习一首歌直到非常完美，它们最终被记录下来了。起初，你记录了鼓声，低音，然后是吉他声，还有其他的声音。每次你录音，工作人员都会把磁带重绕并设置为环绕模式，这样在你演唱的时候录音磁带就会播放之前录制的声音。如果你是低音歌唱，你唱歌的时候就需要把有鼓声的部分作为背景音乐，然后就是吉他声、鼓声、低音（和牛铃声【译注：一种打击乐器，状如四棱锥。】）等等。在每一环，你完成了整个部分，到了下一环，工作人员就开始在磁带上制作你的演唱作品。
|
||||
|
||||
|
||||
你也可以拷贝或换出整个磁带，这是你需要继续录音并且进行多次混合的时候需要做的。
|
||||
|
||||
|
||||
现在我希望对于上述 70 年代的录音工作的描述足够生动，我们就可以把 Git 的工作想象成一个录音磁带了。
|
||||
|
||||
|
||||
### 新建一个 Git 仓库
|
||||
|
||||
|
||||
首先得为我们的虚拟的录音机买一些磁带。在 Git 术语中，这就是仓库；它是完成所有工作的基础，也就是说这里是存放 Git 文件的地方（即 Git 工作区）。
|
||||
|
||||
任何目录都可以是一个 Git 仓库，但是在开始的时候需要进行一次更新。需要下面三个命令：
|
||||
|
||||
|
||||
- 创建目录（如果你喜欢的话，你可以在你的 GUI 文件管理器里面完成。）
|
||||
- 在终端里查看目录。
|
||||
- 初始化这个目录使它可以被 Git管理。
|
||||
|
||||
|
||||
特别是运行如下代码：
|
||||
|
||||
```
|
||||
$ mkdir ~/jupiter # 创建目录
|
||||
$ cd ~/jupiter # 进入目录
|
||||
$ git init . # 初始化你的新 Git 工作区
|
||||
```
|
||||
|
||||
|
||||
在这个例子中，文件夹 jupiter 是空的但却成为了你的 Git 仓库。
|
||||
|
||||
有了仓库接下来的事件就按部就班了。你可以克隆项目仓库，你可以在一个历史点前后来回穿梭（前提是你有一个历史点），创建可交替时间线，然后剩下的工作 Git 就都能正常完成了。
|
||||
|
||||
|
||||
在 Git 仓库里面工作和在任何目录里面工作都是一样的；在仓库中新建文件，复制文件，保存文件。你可以像平常一样完成工作；Git 并不复杂，除非你把它想复杂了。
|
||||
|
||||
在本地的 Git 仓库中，一个文件可以有下面这三种状态：
|
||||
- 未跟踪文件：你在仓库里新建了一个文件，但是你没有把文件加入到 Git 的提交任务（提交暂存区，stage）中。
|
||||
- 已跟踪文件：已经加入到 Git 暂存区的文件。
|
||||
- 暂存区文件：存在于暂存区的文件已经加入到 Git 的提交队列中。
|
||||
|
||||
|
||||
任何你新加入到 Git 仓库中的文件都是未跟踪文件。文件还保存在你的电脑硬盘上，但是你没有告诉 Git 这是需要提交的文件，就像我们的录音机，如果你没有打开录音机；乐队开始演唱了，但是录音机并没有准备录音。
|
||||
|
||||
不用担心，Git 会告诉你存在的问题并提示你怎么解决：
|
||||
```
|
||||
$ echo "hello world" > foo
|
||||
$ git status
|
||||
位于您当前工作的分支 master 上
|
||||
未跟踪文件：
|
||||
（使用 "git add <file>" 更新要提交的内容）
|
||||
foo
|
||||
没有任何提交任务，但是存在未跟踪文件（用 "git add" 命令加入到提交任务）
|
||||
```
|
||||
|
||||
|
||||
你看到了，Git 会提醒你怎样把文件加入到提交任务中。
|
||||
|
||||
### 不使用 Ｇit 命令进行 Git 操作
|
||||
|
||||
|
||||
在 GitHub 或 GitLab（译注：GitLab 是一个用于仓库管理系统的开源项目。使用Git作为代码管理工具，并在此基础上搭建起来的web服务。）上创建一个仓库大多是使用鼠标点击完成的。这不会很难，你单击 New Repository 这个按钮就会很快创建一个仓库。
|
||||
|
||||
在仓库中新建一个 README 文件是一个好习惯，这样人们在浏览你的仓库的时候就可以知道你的仓库基于什么项目，更有用的是通过 README 文件可以确定克隆的是否为一个非空仓库。
|
||||
|
||||
|
||||
克隆仓库通常很简单，但是在 GitHub 上获取仓库改动权限就不简单了，为了进行用户验证你必须有一个 SSH 秘钥。如果你使用 Linux 系统，通过下面的命令可以生成一个秘钥：
|
||||
```
|
||||
$ ssh-keygen
|
||||
```
|
||||
|
||||
|
||||
复制纯文本文件里的秘钥。你可以使用一个文本编辑器打开它，也可以使用 cat 命令：
|
||||
|
||||
```
|
||||
$ cat ~/.ssh/id_rsa.pub
|
||||
```
|
||||
|
||||
|
||||
现在把你的秘钥拷贝到 [GitHub SSH 配置文件][1] 中，或者 [GitLab 配置文件[2]。
|
||||
|
||||
如果你通过使用 SSH 模式克隆了你的项目，就可以在你的仓库开始工作了。
|
||||
|
||||
另外，如果你的系统上没有安装 Git 的话也可以使用 GitHub 的文件上传接口来克隆仓库。
|
||||
|
||||
|
||||
|
||||
|
||||
### 跟踪文件
|
||||
|
||||
命令 git status 的输出会告诉你如果你想让 git 跟踪一个文件，你必须使用命令 git add 把它加入到提交任务中。这个命令把文件存在了暂存区，暂存区存放的都是等待提交的文件，或者把仓库保存为一个快照。git add 命令的最主要目的是为了区分你已经保存在仓库快照里的文件，还有新建的或你想提交的临时文件，至少现在，你都不用为它们之间的不同之处而费神了。
|
||||
|
||||
类比大型录音机，这个动作就像打开录音机开始准备录音一样。你可以按已经录音的录音机上的 pause 按钮来完成推送，或者按下重置按钮等待开始跟踪下一个文件。
|
||||
|
||||
如果你把文件加入到提交任务中，Git 会自动标识为跟踪文件：
|
||||
|
||||
```
|
||||
$ git add foo
|
||||
$ git status
|
||||
位于您当前工作的分支 master 上
|
||||
下列修改将被提交：
|
||||
（使用 "git reset HEAD <file>..." 将下列改动撤出提交任务）
|
||||
新增文件：foo
|
||||
```
|
||||
|
||||
|
||||
加入文件到提交任务中并不会生成一个记录。这仅仅是为了之后方便记录而把文件存放到暂存区。在你把文件加入到提交任务后仍然可以修改文件；文件会被标记为跟踪文件并且存放到暂存区，所以你在最终提交之前都可以改动文件或撤出提交任务（但是请注意：你并没有记录文件，所以如果你完全改变了文件就没有办法撤销了，因为你没有记住最终修改的准确时间。）。
|
||||
|
||||
如果你决定不把文件记录到 Git 历史列表中，那么你可以撤出提交任务，在 Git 中是这样做的：
|
||||
```
|
||||
$ git reset HEAD foo
|
||||
```
|
||||
|
||||
|
||||
这实际上就是删除了录音机里面的录音，你只是在工作区转了一圈而已而已。
|
||||
|
||||
### 大型提交
|
||||
|
||||
有时候，你会需要完成很多提交；我们以录音机类比，这就好比按下录音键并最终按下保存键一样。
|
||||
|
||||
在一个项目从建立到完成，你会按记录键无数次。比如，如果你通过你的方式使用一个新的 Python 工具包并且最终实现了窗口展示，然后你就很肯定的提交了文件，但是不可避免的会发生一些错误，现在你却不能撤销你的提交操作了。
|
||||
|
||||
一次提交会记录仓库中所有的暂存区文件。Git 只记录加入到提交任务中的文件，也就是说在过去某个时刻你使用 git add 命令加入到暂存区的所有文件。还有从先前的提交开始被改动的文件。如果没有其他的提交，所有的跟踪文件都包含在这次提交中，因为在浏览 Git 历史点的时候，它们没有存在于仓库中。
|
||||
|
||||
完成一次提交需要运行下面的命令：
|
||||
```
|
||||
$ git commit -m 'My great project, first commit.'
|
||||
```
|
||||
|
||||
这就保存了所有需要在仓库中提交的文件（或者，如果你说到 Gallifreyan【译注：英国电视剧《神秘博士》里的时间领主使用的一种优雅的语言，】,它们可能就是“固定的时间点” ）。你不仅能看到整个提交记录，还能通过 git log 命令查看修改日志找到提交时的版本号：
|
||||
```
|
||||
$ git log --oneline
|
||||
55df4c2 My great project, first commit.
|
||||
```
|
||||
|
||||
|
||||
如果想浏览更多信息，只需要使用不带 --oneline 选项的 git log 命令。
|
||||
|
||||
|
||||
在这个例子中提交时的版本号是 55df4c2。它被叫做 commit hash（译注：一个SHA-1生成的哈希码，用于表示一个git commit对象。），它表示着刚才你的提交包含的所有改动，覆盖了先前的记录。如果你想要“倒回”到你的提交历史点上就可以用这个 commit hash 作为依据。
|
||||
|
||||
你可以把 commit hash 想象成一个声音磁带上的 [SMPTE timecode][3],或者再夸张一点，这就是好比一个黑胶唱片上两首不同的歌之间的不同点，或是一个 CD 上的轨段编号。
|
||||
|
||||
|
||||
你在很久前改动了文件并且把它们加入到提交任务中，最终完成提交，这就会生成新的 commit hashes，每个 commit hashes 标示的历史点都代表着你的产品不同的版本。
|
||||
|
||||
|
||||
这就是 Charlie Brown 把 Git 称为版本控制系统的原因。
|
||||
|
||||
在接下来的文章中，我们将会讨论你需要知道的关于 Git HEAD 的一切，我们不准备讨论关于 Git 的提交历史问题。基本不会提及，但是你可能会需要了解它（或许你已经有所了解？）。
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/life/16/7/creating-your-first-git-repository
|
||||
|
||||
作者：[Seth Kenlon][a]
|
||||
译者：[vim-kakali](https://github.com/vim-kakali)
|
||||
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
|
||||
[1]: https://github.com/settings/keys
|
||||
[2]: https://gitlab.com/profile/keys
|
||||
[3]: http://slackermedia.ml/handbook/doku.php?id=timecode
|
||||
71
translated/tech/20160718 OPEN SOURCE ACCOUNTING SOFTWARE.md
Normal file
71
translated/tech/20160718 OPEN SOURCE ACCOUNTING SOFTWARE.md
Normal file
@ -0,0 +1,71 @@
|
||||
GNU KHATA：开源的会计管理软件
|
||||
============================================
|
||||
|
||||
作为一个活跃的 Linux 爱好者，我经常向我的朋友们介绍 Linux，帮助他们选择最适合他们的发行版本，同时也会帮助他们安装一些适用于他们工作的开源软件。
|
||||
|
||||
但是，又一次，我就变得很无奈。我的叔叔，他是一个自由职业的会计师。他会有一系列的为了会计工作的付费软件。我就不那么确定，我能在在开软软件中找到这么一款可以替代的软件。直到昨天。
|
||||
|
||||
Abhishek 给我推荐了一些[很酷的软件][1]，并且，GNU Khata 这个特殊的一款，脱颖而出。
|
||||
|
||||
[GNU Khata][2] 是一个会计工具。 或者，我可以说成是一系列的会计工具集合？这像经济管理方面的[Evernote][3]。他的应用是如此之广，以至于他可以处理个人的财务管理，到大型公司的管理，从店铺存货管理到税率计算，都可以有效处理。
|
||||
|
||||
对你来说一个有趣的点，'Khata' 在印度或者是其他的印度语国家中意味着账户，所以这个会计软件叫做 GNU Khata。
|
||||
|
||||
### 安装
|
||||
|
||||
互联网上有很多关于老旧版本的 Khata 安装的介绍。现在，GNU Khata 已经可以在 Debian/Ubuntu 和他们的衍生产中得到。我建议你按照如下 GNU Khata 官网的步骤来安装。我们来一次快速的入门。
|
||||
|
||||
- 从[这][4]下载安装器。
|
||||
- 在下载目录打开终端。
|
||||
- 粘贴复制以下的代码到终端，并且执行。
|
||||
|
||||
```
|
||||
sudo chmod 755 GNUKhatasetup.run
|
||||
sudo ./GNUKhatasetup.run
|
||||
```
|
||||
|
||||
- 这就结束了，从你的 Dash 或者是应用菜单中启动 GNU Khata 吧。
|
||||
### 第一次启动
|
||||
|
||||
GNU Khata 在浏览器中打开，并且展现以下的画面。
|
||||
|
||||
|
||||
|
||||
填写组织的名字和组织形式，经济年份并且点击 proceed 按钮进入管理设置页面。
|
||||
|
||||
|
||||
|
||||
仔细填写你的姓名，密码，安全问题和他的答案，并且点击“create and login”。
|
||||
|
||||
|
||||
|
||||
你已经全部设置完成了。使用菜单栏来开始使用 GNU Khata 来管理你的经济吧。这很容易。
|
||||
|
||||
### GNU KHATA 真的是市面上付费会计应用的竞争对手吗？
|
||||
|
||||
首先，GNU Khata 让所有的事情变得简单。顶部的菜单栏被方便的组织，可以帮助你有效的进行工作。 你可以选择管理不同的账户和项目，并且切换非常容易。[他们的官网][5]表明，GNU Khata 可以“方便的转变成印度语”。同时，你知道 GNU Khata 也可以在云端使用吗？
|
||||
|
||||
所有的主流的账户管理工具，将账簿分类，项目介绍，法规介绍等等用专业的方式整理，并且支持自定义整理和实时显示。这让会计和进存储管理看起来如此的简单。
|
||||
|
||||
这个项目正在积极的发展，从实际的操作中提交反馈来帮助这个软件更加进步。考虑到软件的成熟性，使用的便利性还有免费的 tag。GNU Khata 可能会成为最好的账簿助手。
|
||||
|
||||
请在评论框里留言吧，让我们知道你是如何看待 GNU Khata 的。
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/using-gnu-khata/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ItsFoss+%28Its+FOSS%21+An+Open+Source+Blog%29
|
||||
|
||||
作者：[Aquil Roshan][a]
|
||||
译者：[MikeCoder](https://github.com/MikeCoder)
|
||||
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/aquil/
|
||||
[1]: https://itsfoss.com/category/apps/
|
||||
[2]: http://www.gnukhata.in/
|
||||
[3]: https://evernote.com/
|
||||
[4]: https://cloud.openmailbox.org/index.php/s/L8ppsxtsFq1345E/download
|
||||
[5]: http://www.gnukhata.in/
|
||||
@ -0,0 +1,37 @@
|
||||
你能在浏览器中运行UBUNTU
|
||||
=====================================================
|
||||
|
||||
Canonical, Ubuntu的母公司, 为Linux推广做了很多努力. 无论你有多么不喜欢 Ubuntu, 你必须承认它对 “Linux 易用性”的影响. Ubuntu 以及其衍生是应用最多的Linux版本 .
|
||||
|
||||
为了进一步推广 Ubuntu Linux, Canonical 把它放到了浏览器里你可以再任何地方使用 [demo version of Ubuntu][1]. 它将帮你更好的体验 Ubuntu. 以便让新人更容易决定是否使用.
|
||||
|
||||
你可能争辩说USB版的linux更好. 我同意但是你要知道你要下载ISO, 创建USB驱动, 修改配置文件. 并不是每个人都乐意这么干的. 在线体验是一个更好的选择.
|
||||
|
||||
因此, 你能在Ubuntu在线看到什么. 实际上并不多.
|
||||
|
||||
你可以浏览文件, 你可以使用 Unity Dash, 浏览 Ubuntu Software Center, 甚至装几个 apps (当然它们不会真的安装), 看一看文件浏览器 和其它一些东西. 以上就是全部了. 但是在我看来, 它是非常漂亮的
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
如果你的朋友或者家人想试试Linux又不乐意安装, 你可以给他们以下链接:
|
||||
|
||||
[Ubuntu Online Tour][0]
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/ubuntu-online-demo/?utm_source=newsletter&utm_medium=email&utm_campaign=linux_and_open_source_stories_this_week
|
||||
|
||||
作者：[Abhishek Prakash][a]
|
||||
译者：[kokialoves](https://github.com/kokialoves)
|
||||
校对：[校对ID](https://github.com/校对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/
|
||||
[0]: http://tour.ubuntu.com/en/
|
||||
[1]: http://tour.ubuntu.com/en/
|
||||
@ -0,0 +1,39 @@
|
||||
为你的Linux桌面设置一张真实的地球照片
|
||||
=================================================================
|
||||
|
||||
|
||||
|
||||
厌倦了看同样的桌面背景了么？这里有一个几乎这世界上最好的东西。
|
||||
|
||||
‘[Himawaripy][1]‘是一个Python 3脚本，它会接近实时抓取由[日本Himawari 8气象卫星][2]拍摄的地球照片，并将它设置成你的桌面背景。
|
||||
|
||||
安装完成后，你可以将它设置成每10分钟运行的任务（自然地它是在后台运行），这样它就可以实时地取回地球的照片并设置成背景了。
|
||||
|
||||
因为Himawari-8是一颗同步轨道卫星，你只能看到澳大利亚上空的地球的图片-但是它实时的天气形态、云团和光线仍使它很壮丽，即使对我而言在看到英国上方的更好！
|
||||
|
||||
高级设置允许你配置从卫星取回的图片质量，但是要记住增加图片质量会增加文件大小及更长的下载等待！
|
||||
|
||||
最后，虽然这个脚本与其他我们提到过的其他类似，它还仍保持更新及可用。
|
||||
|
||||
获取Himawaripy
|
||||
|
||||
Himawaripy已经在一系列的桌面环境中都测试过了，包括Unity、LXDE、i3、MATE和其他桌面环境。它是免费、开源软件但是并不能直接设置及配置。
|
||||
|
||||
在Github上查找获取安装的应用程序和设置的所有指令（）提示：有没有一键安装）上。
|
||||
|
||||
[GitHub上的实时地球壁纸脚本][0]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/mandatory-access-control-with-selinux-or-apparmor-linux/
|
||||
|
||||
作者：[ JOEY-ELIJAH SNEDDON][a]
|
||||
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://plus.google.com/117485690627814051450/?rel=author
|
||||
[1]: https://github.com/boramalper/himawaripy
|
||||
[2]: https://en.wikipedia.org/wiki/Himawari_8
|
||||
[0]: https://github.com/boramalper/himawaripy
|
||||
@ -1,178 +0,0 @@
|
||||
LFCS第十二讲: 如何使用Linux的帮助文档和工具
|
||||
==================================================================================
|
||||
|
||||
由于 2016 年 2 月 2 号开始启用了新的 LFCS 考试要求, 我们在[LFCS series][1]系列添加了一些必要的内容 . 为了考试的需要, 我们强烈建议你看一下[LFCE series][2] .
|
||||
|
||||
|
||||
>LFCS: 了解Linux的帮助文档和工具
|
||||
|
||||
当你习惯了在命令行下进行工作, 你会发现Linux有许多文档需要你去使用和配置Linux系统.
|
||||
|
||||
另一个你必须熟悉命令行帮助工具的理由是，在[LFCS][3] 和 [LFCE][4] 考试中, 你只能靠你自己和命令行工具，没有互联网也没有百度。
|
||||
|
||||
基于上面的理由, 在这一章里我们将给你一些建议来帮助你通过**Linux Foundation Certification** 考试.
|
||||
|
||||
### Linux 帮助手册
|
||||
|
||||
man命令, 大体上来说就是一个工具手册. 它包含选项列表(和解释) , 甚至还提供一些例子.
|
||||
|
||||
我们用**man command** 加工具名称来打开一个帮助手册以便获取更多内容. 例如:
|
||||
|
||||
```
|
||||
# man diff
|
||||
```
|
||||
|
||||
我们将打开`diff`的手册页, 这个工具将一行一行的对比文本文档 (如你想退出只需要轻轻的点一下Q键).
|
||||
|
||||
下面我来比较两个文本文件 `file1` 和 `file2` . 这两个文本文件包含着相同版本Linux的安装包信息.
|
||||
|
||||
输入`diff` 命令它将告诉我们 `file1` 和`file2` 有什么不同:
|
||||
|
||||
```
|
||||
# diff file1 file2
|
||||
```
|
||||
|
||||
|
||||
>在Linux中比较两个文本文件
|
||||
|
||||
`<` 这个符号是说`file2`少一行. 如果是 `file1`少一行, 我们将用 `>` 符号来替代.
|
||||
|
||||
接下来说, **7d6** 意思是说 文件1的**#7**行在 `file2`中被删除了 ( **24d22** 和**41d38**是同样的意思), 65,67d61告诉我们移动 **65** 到 **67** . 我们把以上步骤都做了两个文件将完全匹配.
|
||||
|
||||
你还可以通过 `-y` 选项来对比两个文件:
|
||||
|
||||
```
|
||||
# diff -y file1 file2
|
||||
```
|
||||
|
||||
|
||||
>通过列表来列出两个文件的不同
|
||||
|
||||
当然你也可以用`diff`来比较两个二进制文件 . 如果它们完全一样, `diff` 将什么也不会输出. 否则, 他将会返回如下信息: “**Binary files X and Y differ**”.
|
||||
|
||||
### –help 选项
|
||||
|
||||
`--help`选项 , 大多数命令都可以用它(并不是所有) , 他可以理解为一个命令的简单介绍. 尽管它不提供工具的详细介绍, 但是确实是一个能够快速列出程序使用信息的不错的方法.
|
||||
|
||||
例如,
|
||||
|
||||
```
|
||||
# sed --help
|
||||
```
|
||||
|
||||
显示 sed 的每个选项的用法(sed文本流编辑器).
|
||||
|
||||
一个经典的`sed`例子，替换文件字符. 用 `-i` 选项 (描述为 “**编辑文件在指定位置**”), 你可以编辑一个文件而且并不需要打开他. 如果你想要备份一个原始文件, 用 `-i` 选项 加后缀来创建一个原始文件的副本.
|
||||
|
||||
例如, 替换 `lorem.txt`中的`Lorem` 为 `Tecmint` (忽略大小写) 并且创建一个新的原始文件副本, 命令如下:
|
||||
|
||||
```
|
||||
# less lorem.txt | grep -i lorem
|
||||
# sed -i.orig 's/Lorem/Tecmint/gI' lorem.txt
|
||||
# less lorem.txt | grep -i lorem
|
||||
# less lorem.txt.orig | grep -i lorem
|
||||
```
|
||||
|
||||
请注意`lorem.txt`文件中`Lorem` 都已经替换为 `Tecmint` , 并且原始的 `lorem.txt` 保存为`lorem.txt.orig`.
|
||||
|
||||
|
||||
>替换文件文本
|
||||
|
||||
### /usr/share/doc内的文档
|
||||
这可能是我最喜欢的方法. 如果你进入 `/usr/share/doc` 目录, 你可以看到好多Linux已经安装的工具的名称的文件夹.
|
||||
|
||||
根据[Filesystem Hierarchy Standard][5](文件目录标准),这些文件夹包含了许多帮助手册没有的信息, 还有一些模板和配置文件.
|
||||
|
||||
例如, 让我们来看一下 `squid-3.3.8` (版本可能会不同) 一个非常受欢迎的HTTP代理[squid cache server][6].
|
||||
|
||||
让我们用`cd`命令进入目录 :
|
||||
|
||||
```
|
||||
# cd /usr/share/doc/squid-3.3.8
|
||||
```
|
||||
|
||||
列出当前文件夹列表:
|
||||
|
||||
```
|
||||
# ls
|
||||
```
|
||||
|
||||
|
||||
>ls linux列表命令
|
||||
|
||||
你应该特别注意 `QUICKSTART` 和 `squid.conf.documented`. 这两个文件包含了Squid许多信息, . 对于别的安装包来说, 他们的名字可能不同 (有可能是 **QuickRef** 或者**00QUICKSTART**), 但原理是一样的.
|
||||
|
||||
对于另外一些安装包, 比如 the Apache web server, 在`/usr/share/doc`目录提供了配置模板, 当你配置独立服务器或者虚拟主机的时候会非常有用.
|
||||
|
||||
### GNU 信息文档
|
||||
|
||||
你可以把它想象为帮助手册的超级链接形式. 正如上面说的, 他不仅仅提供工具的帮助信息, 而且还是超级链接的形式(是的!在命令行中的超级链接) 你可以通过箭头按钮和回车按钮来浏览你需要的内容.
|
||||
|
||||
一个典型的例子是:
|
||||
|
||||
```
|
||||
# info coreutils
|
||||
```
|
||||
|
||||
通过coreutils 列出当前系统的 基本文件，shell脚本和文本处理工具[basic file, shell and text manipulation utilities][7] , 你可以得到他们的详细介绍.
|
||||
|
||||
|
||||
>Info Coreutils
|
||||
|
||||
和帮助手册一样你可以按Q键退出.
|
||||
|
||||
此外, GNU info 还可以像帮助手册一样使用. 例如:
|
||||
|
||||
```
|
||||
# info tune2fs
|
||||
```
|
||||
|
||||
它将显示 **tune2fs**的帮助手册, ext2/3/4 文件系统管理工具.
|
||||
|
||||
让我们来看看怎么用**tune2fs**:
|
||||
|
||||
显示 **/dev/mapper/vg00-vol_backups**文件系统信息:
|
||||
|
||||
```
|
||||
# tune2fs -l /dev/mapper/vg00-vol_backups
|
||||
```
|
||||
|
||||
修改文件系统标签 (修改为Backups):
|
||||
|
||||
```
|
||||
# tune2fs -L Backups /dev/mapper/vg00-vol_backups
|
||||
```
|
||||
|
||||
设置 `/` 自检的挂载次数 (用`-c` 选项设置 `/`的自检的挂载次数 或者用 `-i` 选项设置 自检时间 **d=days, w=weeks, and m=months**).
|
||||
|
||||
```
|
||||
# tune2fs -c 150 /dev/mapper/vg00-vol_backups # Check every 150 mounts
|
||||
# tune2fs -i 6w /dev/mapper/vg00-vol_backups # Check every 6 weeks
|
||||
```
|
||||
|
||||
以上这些内容也可以通过 `--help` 选项找到, 或者查看帮助手册.
|
||||
|
||||
### 摘要
|
||||
|
||||
不管你选择哪种方法，知道并且会使用它们在考试中对你是非常有用的. 你知道其它的一些方法吗? 欢迎给我们留言.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/linux-basic-shell-scripting-and-linux-filesystem-troubleshooting/
|
||||
|
||||
作者：[Gabriel Cánepa][a]
|
||||
译者：[kokialoves](https://github.com/kokialoves)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://www.tecmint.com/author/gacanepa/
|
||||
[1]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/
|
||||
[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/
|
||||
[3]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/
|
||||
[4]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/
|
||||
[5]: http://www.tecmint.com/linux-directory-structure-and-important-files-paths-explained/
|
||||
[6]: http://www.tecmint.com/configure-squid-server-in-linux/
|
||||
[7]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/
|
||||
[8]:
|
||||
@ -1,76 +0,0 @@
|
||||
|
||||
|
||||
在 Linux 上怎么读取标准输入(STDIN)作为 Awk 的输入
|
||||
============================================
|
||||
|
||||
|
||||
|
||||
|
||||
在 Awk 工具系列的前几节，我们看到大多数操作都是从一个文件或多个文件读取输入，或者你想要把标准输入作为 Awk 的输入．
|
||||
在 Awk 系列的第７节中，我们将会看到几个例子，这些例子都是关于你可以筛选其他命令的输出代替从一个文件读取输入作为 awk 的输入．
|
||||
|
||||
|
||||
我们开始使用 [dir utility][1] , dir 命令和 [ls 命令][2] 相似，在第一个例子下面，我们使用 'dir -l' 命令的输出作为 Awk 命令的输入，这样就可以打印出文件拥有者的用户名，所属组组名以及在当前路径下他／她拥有的文件．
|
||||
```
|
||||
# dir -l | awk '{print $3, $4, $9;}'
|
||||
```
|
||||
|
||||
|
||||
>列出当前路径下的用户文件
|
||||
|
||||
|
||||
看另一个例子，我们 [使用 awk 表达式][3] ，在这里，我们想要在 awk 命令里使用一个表达式筛选出字符串，通过这样来打印出 root 用户的文件．命令如下:
|
||||
```
|
||||
# dir -l | awk '$3=="root" {print $1,$3,$4, $9;} '
|
||||
```
|
||||
|
||||
|
||||
>列出 root 用户的文件
|
||||
|
||||
|
||||
上面的命令包含了 '(==)' 来进行比较操作，这帮助我们在当前路径下筛选出 root 用户的文件.这种方法的实现是通过使用 '$3=="root"' 表达式．
|
||||
|
||||
让我们再看另一个例子，我们使用一个 [awk 比较运算符][4] 来匹配一个确定的字符串．
|
||||
|
||||
|
||||
现在，我们已经用了 [cat utility][5] 来浏览文件名为 tecmint_deals.txt 的文件内容，并且我们想要仅仅查看有字符串 Tech 的部分，所以我们会运行下列命令:
|
||||
```
|
||||
# cat tecmint_deals.txt
|
||||
# cat tecmint_deals.txt | awk '$4 ~ /tech/{print}'
|
||||
# cat tecmint_deals.txt | awk '$4 ~ /Tech/{print}'
|
||||
```
|
||||
|
||||
|
||||
>用 Awk 比较运算符匹配字符串
|
||||
|
||||
|
||||
在上面的例子中，我们已经用了参数为 `~ /匹配字符/` 的比较操作,但是上面的两个命令给我们展示了一些很重要的问题．
|
||||
|
||||
当你运行带有 tech 字符串的命令时终端没有输出，因为在文件中没有 tech 这种字符串，但是运行带有 Tech 字符串的命令，你却会得到包含 Tech 的输出．
|
||||
|
||||
所以你应该在进行这种比较操作的时候时刻注意这种问题，正如我们在上面看到的那样， awk 对大小写很敏感．
|
||||
|
||||
|
||||
你可以一直使用另一个命令的输出作为 awk 命令的输入来代替从一个文件中读取输入，这就像我们在上面看到的那样简单．
|
||||
|
||||
|
||||
希望这些例子足够简单可以使你理解 awk 的用法，如果你有任何问题，你可以在下面的评论区提问，记得查看 awk 系列接下来的章节内容，我们将关注 awk 的一些功能，比如变量，数字表达式以及赋值运算符．
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/read-awk-input-from-stdin-in-linux/
|
||||
|
||||
作者：[Aaron Kili][a]
|
||||
译者：[vim-kakali](https://github.com/vim-kakali)
|
||||
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
|
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[a]: http://www.tecmint.com/author/aaronkili/
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[1]: http://www.tecmint.com/linux-dir-command-usage-with-examples/
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[2]: http://www.tecmint.com/15-basic-ls-command-examples-in-linux/
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[3]: http://www.tecmint.com/combine-multiple-expressions-in-awk
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[4]: http://www.tecmint.com/comparison-operators-in-awk
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[5]: http://www.tecmint.com/13-basic-cat-command-examples-in-linux/
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