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@ -1,52 +1,53 @@
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||||
使用 iftop 命令监控网络带宽
|
||||
======
|
||||
系统管理员需要监控 IT 基础设施来确保一切正常运行。我们需要监控硬件也就是内存、硬盘和 CPU 等的性能，我们也必须监控我们的网络。我们需要确保我们的网络不被过度使用，或者我们的程序，网站可能无法正常工作。在本教程中，我们将学习使用 IFTOP。
|
||||
|
||||
系统管理员需要监控 IT 基础设施来确保一切正常运行。我们需要监控硬件，也就是内存、硬盘和 CPU 等的性能，我们也必须监控我们的网络。我们需要确保我们的网络不被过度使用，否则我们的程序，网站可能无法正常工作。在本教程中，我们将学习使用 `iftop`。
|
||||
|
||||
（**推荐阅读**：[**使用 Nagios** 进行资源监控][1]、[**用于检查系统信息的工具**][2] 、[**要监控的重要日志**][3] ）
|
||||
|
||||
Iftop 是网络监控工具，它提供实时带宽监控。 Iftop 测量进出各个套接字连接的总数据量，即它捕获通过网络适配器收到或发出的数据包，然后将这些数据相加以得到使用的带宽。
|
||||
`iftop` 是网络监控工具，它提供实时带宽监控。 `iftop` 测量进出各个套接字连接的总数据量，即它捕获通过网络适配器收到或发出的数据包，然后将这些数据相加以得到使用的带宽。
|
||||
|
||||
## 在 Debian/Ubuntu 上安装
|
||||
### 在 Debian/Ubuntu 上安装
|
||||
|
||||
Iftop 存在于 Debian/Ubuntu 的默认仓库中，可以使用下面的命令安装：
|
||||
iftop 存在于 Debian/Ubuntu 的默认仓库中，可以使用下面的命令安装：
|
||||
|
||||
```
|
||||
$ sudo apt-get install iftop
|
||||
```
|
||||
|
||||
## 使用 yum 在 RHEL/Centos 上安装
|
||||
### 使用 yum 在 RHEL/Centos 上安装
|
||||
|
||||
要在 CentOS 或 RHEL 上安装 iftop，我们需要启用 EPEL 仓库。要启用仓库，请在终端上运行以下命令：
|
||||
|
||||
### RHEL/CentOS 7
|
||||
**RHEL/CentOS 7：**
|
||||
|
||||
```
|
||||
$ rpm -Uvh https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-10.noarch.rpm
|
||||
```
|
||||
|
||||
### RHEL/CentOS 6（64位）
|
||||
**RHEL/CentOS 6（64 位）：**
|
||||
|
||||
```
|
||||
$ rpm -Uvh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
|
||||
```
|
||||
|
||||
### RHEL/CentOS 6 （64位）
|
||||
**RHEL/CentOS 6 （32 位）：**
|
||||
|
||||
```
|
||||
$ rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
|
||||
```
|
||||
|
||||
epel 仓库安装完成后，我们可以用下面的命令安装 iftop：
|
||||
EPEL 仓库安装完成后，我们可以用下面的命令安装 `iftop`：
|
||||
|
||||
```
|
||||
$ yum install iftop
|
||||
```
|
||||
|
||||
这将在你的系统上安装 iftop。我们现在将用它来监控我们的网络。
|
||||
这将在你的系统上安装 `iftop`。我们现在将用它来监控我们的网络。
|
||||
|
||||
## 使用 IFTOP
|
||||
### 使用 iftop
|
||||
|
||||
可以打开终端窗口，并输入下面的命令使用 iftop：
|
||||
可以打开终端窗口，并输入下面的命令使用 `iftop`：
|
||||
|
||||
```
|
||||
$ iftop
|
||||
@ -60,19 +61,19 @@ $ iftop
|
||||
$ iftop -n
|
||||
```
|
||||
|
||||
这将在屏幕上显示网络信息，但使用 “-n”，则不会显示与 IP 地址相关的名称，只会显示 IP 地址。这个选项能节省一些将 IP 地址解析为名称的带宽。
|
||||
这将在屏幕上显示网络信息，但使用 `-n`，则不会显示与 IP 地址相关的名称，只会显示 IP 地址。这个选项能节省一些将 IP 地址解析为名称的带宽。
|
||||
|
||||
我们也可以看到 iftop 可以使用的所有命令。运行 iftop 后，按下键盘上的 “h” 查看 iftop 可以使用的所有命令。
|
||||
我们也可以看到 `iftop` 可以使用的所有命令。运行 `iftop` 后，按下键盘上的 `h` 查看 `iftop` 可以使用的所有命令。
|
||||
|
||||
![network monitoring][7]
|
||||
|
||||
要监控特定的网络接口，我们可以在 iftop 后加上接口名：
|
||||
要监控特定的网络接口，我们可以在 `iftop` 后加上接口名：
|
||||
|
||||
```
|
||||
$ iftop -I enp0s3
|
||||
```
|
||||
|
||||
如上所述，你可以使用帮助来查看 iftop 可以使用的更多选项。但是这些提到的例子只是可能只是监控网络。
|
||||
如上所述，你可以使用帮助来查看 `iftop` 可以使用的更多选项。但是这些提到的例子只是可能只是监控网络。
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
@ -81,7 +82,7 @@ via: http://linuxtechlab.com/monitoring-network-bandwidth-iftop-command/
|
||||
|
||||
作者：[SHUSAIN][a]
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
@ -1,6 +1,7 @@
|
||||
如何更改 Linux 控制台上的字体
|
||||
======
|
||||
|
||||
|
||||
|
||||
|
||||
我尝试尽可能的保持心灵祥和，然而总有一些事情让我意难平，比如控制台字体太小了。记住我的话，朋友，有一天你的眼睛会退化，无法再看清你编码时用的那些细小字体，到那时你就后悔莫及了。
|
||||
|
||||
@ -8,46 +9,48 @@
|
||||
|
||||
### Linux 控制台是个什么鬼？
|
||||
|
||||
首先让我们来澄清一下我们说的到底是个什么东西。当我提到 Linux 控制台，我指的是 TTY1-6，即你从图形环境用 `Ctrl-Alt-F1` 到 `F6` 切换到的虚拟终端。按下 `Ctrl+Alt+F7` 会切回图形环境。(不过这些热键已经不再通用，你的 Linux 发行版可能有不同的键映射。你的 TTY 的数量也可能不同，你图形环境会话也可能不在 `F7`。比如，Fedora 的默认图形会话是 `F2`，它只有一个额外的终端在 `F1`。) 我觉得能同时拥有 X 会话和终端绘画实在是太酷了。
|
||||
首先让我们来澄清一下我们说的到底是个什么东西。当我提到 Linux 控制台，我指的是 TTY1-6，即你从图形环境用 `Ctrl-Alt-F1` 到 `F6` 切换到的虚拟终端。按下 `Ctrl+Alt+F7` 会切回图形环境。(不过这些热键已经不再通用，你的 Linux 发行版可能有不同的键映射。你的 TTY 的数量也可能不同，你图形环境会话也可能不在 `F7`。比如，Fedora 的默认图形会话是 `F2`，它只有一个额外的终端在 `F1`。) 我觉得能同时拥有 X 会话和终端会话实在是太酷了。
|
||||
|
||||
Linux 控制台是内核的一部分，而且并不运行在 X 会话中。它和你在没有图形环境的无头服务器中用的控制台是一样的。我称呼在图形会话中的 X 终端为终端，而将控制台和 X 终端统称为终端模拟器。
|
||||
Linux 控制台是内核的一部分，而且并不运行在 X 会话中。它和你在没有图形环境的<ruby>无头<rt>headless</rt></ruby>服务器中用的控制台是一样的。我称呼在图形会话中的 X 终端为终端，而将控制台和 X 终端统称为终端模拟器。
|
||||
|
||||
但这还没完。Linux 终端从早期的 ANSI 时代开始已经经历了长久的发展，多亏了 Linux framebuffer，它现在支持 Unicode 并且对图形也有了有限的一些支持。而且出现了很多在控制台下运行的多媒体应用，这些我们在以后的文章中会提到。
|
||||
但这还没完。Linux 终端从早期的 ANSI 时代开始已经经历了长久的发展，多亏了 Linux framebuffer，它现在支持 Unicode 并且对图形也有了有限的一些支持。而且出现了很多在控制台下运行的[多媒体应用][4]，这些我们在以后的文章中会提到。
|
||||
|
||||
### 控制台截屏
|
||||
|
||||
获取控制台截屏的最简单方法是让控制台跑在虚拟机内部。然后你可以在宿主系统上使用中意的截屏软件来抓取。不过借助 [fbcat][1] 和 [fbgrab][2] 你也可以直接在控制台上截屏。`fbcat` 会创建一个可移植的像素映射格式 (PPM) 图像; 这是一个高度可移植的未压缩图像格式，可以在所有的操作系统上读取，当然你也可以把它转换成任何喜欢的其他格式。`fbgrab` 则是 `fbcat` 的一个封装脚本，用来生成一个 PNG 文件。不同的人写过多个版本的 `fbgrab`。每个版本的选项都有限而且只能创建截取全屏。
|
||||
获取控制台截屏的最简单方法是让控制台跑在虚拟机内部。然后你可以在宿主系统上使用中意的截屏软件来抓取。不过借助 [fbcat][1] 和 [fbgrab][2] 你也可以直接在控制台上截屏。`fbcat` 会创建一个可移植的像素映射格式（PPM）的图像； 这是一个高度可移植的未压缩图像格式，可以在所有的操作系统上读取，当然你也可以把它转换成任何喜欢的其他格式。`fbgrab` 则是 `fbcat` 的一个封装脚本，用来生成一个 PNG 文件。很多人写过多个版本的 `fbgrab`。每个版本的选项都有限而且只能创建截取全屏。
|
||||
|
||||
`fbcat` 的执行需要 root 权限，而且它的输出需要重定向到文件中。你无需指定文件扩展名，只需要输入文件名就行了：
|
||||
|
||||
```
|
||||
$ sudo fbcat > Pictures/myfile
|
||||
|
||||
```
|
||||
|
||||
在 GIMP 中裁剪后，就得到了图 1。
|
||||
|
||||
|
||||
Figure 1：View after cropping。
|
||||
|
||||
*图 1 ： 裁剪后查看*
|
||||
|
||||
如果能在左边空白处有一点填充就好了，如果有读者知道如何实现请在留言框中告诉我。
|
||||
|
||||
`fbgrab` 还有一些选项，你可以通过 `man fbgrab` 来查看，这些选项包括对另一个控制台进行截屏，以及延时截屏。在下面的例子中可以看到，`fbgrab` 截屏跟 `fbcat` 截屏类似，只是你无需明确进行输出重定性了：
|
||||
`fbgrab` 还有一些选项，你可以通过 `man fbgrab` 来查看，这些选项包括对另一个控制台进行截屏，以及延时截屏等。在下面的例子中可以看到，`fbgrab` 截屏跟 `fbcat` 截屏类似，只是你无需明确进行输出重定性了：
|
||||
|
||||
```
|
||||
$ sudo fbgrab Pictures/myOtherfile
|
||||
|
||||
```
|
||||
|
||||
### 查找字体
|
||||
|
||||
就我所知，除了查看字体存储目录 `/usr/share/consolefonts/`(Debian/etc。)，`/lib/kbd/consolefonts/` (Fedora)，`/usr/share/kbd/consolefonts` (openSUSE)，外没有其他方法可以列出已安装的字体了。
|
||||
就我所知，除了查看字体存储目录 `/usr/share/consolefonts/`（Debian 等），`/lib/kbd/consolefonts/` （Fedora），`/usr/share/kbd/consolefonts` （openSUSE）外没有其他方法可以列出已安装的字体了。
|
||||
|
||||
### 更改字体
|
||||
|
||||
可读字体不是什么新概念。我们应该尊重以前的经验！可读性是很重要的。可配置性也很重要，然而现如今却不怎么看重了。
|
||||
|
||||
在 Debian/Ubuntu/ 等系统上，可以运行 `sudo dpkg-reconfigure console-setup` 来设置控制台字体，然后在控制台运行 `setupcon` 命令来让变更生效。`setupcon` 属于 `console-setup` 软件包中的一部分。若你的 Linux 发行版中不包含该工具，可以在 [openSUSE][3] 中下载到它。
|
||||
在 Debian/Ubuntu 等系统上，可以运行 `sudo dpkg-reconfigure console-setup` 来设置控制台字体，然后在控制台运行 `setupcon` 命令来让变更生效。`setupcon` 属于 `console-setup` 软件包中的一部分。若你的 Linux 发行版中不包含该工具，可以在 [openSUSE][3] 中下载到它。
|
||||
|
||||
你也可以直接编辑 `/etc/default/console-setup` 文件。下面这个例子中设置字体为 32 点大小的 Terminus Bold 字体，这是我的最爱，并且严格限制控制台宽度为 80 列。
|
||||
|
||||
```
|
||||
ACTIVE_CONSOLES="/dev/tty[1-6]"
|
||||
CHARMAP="UTF-8"
|
||||
@ -55,22 +58,20 @@ CODESET="guess"
|
||||
FONTFACE="TerminusBold"
|
||||
FONTSIZE="16x32"
|
||||
SCREEN_WIDTH="80"
|
||||
|
||||
```
|
||||
|
||||
这里的 FONTFACE 和 FONTSIZE 的值来自于字体的文件名，`TerminusBold32x16.psf.gz`。是的，你需要反转 FONTSIZE 中值的顺序。计算机就是这么搞笑。然后再运行 `setupcon` 来让新配置生效。可以使用 `showconsolefont` 来查看当前所用字体的所有字符集。要查看完整的选项说明请参考 `man console-setup`。
|
||||
这里的 `FONTFACE` 和 `FONTSIZE` 的值来自于字体的文件名 `TerminusBold32x16.psf.gz`。是的，你需要反转 `FONTSIZE` 中值的顺序。计算机就是这么搞笑。然后再运行 `setupcon` 来让新配置生效。可以使用 `showconsolefont` 来查看当前所用字体的所有字符集。要查看完整的选项说明请参考 `man console-setup`。
|
||||
|
||||
### Systemd
|
||||
|
||||
Systemd 与 `console-setup` 不太一样，除了字体之外，你无需安装任何东西。你只需要编辑 `/etc/vconsole.conf` 然后重启就行了。我在 Fedora 和 openSUSE 系统中安装了一些额外的大型号的 Terminus 字体包，因为默认安装的字体最大只有 16 点而我想要的是 32 点。然后将 `/etc/vconsole.conf` 的内容修改为：
|
||||
Systemd 与 `console-setup` 不太一样，除了字体之外，你无需安装任何东西。你只需要编辑 `/etc/vconsole.conf` 然后重启就行了。我在 Fedora 和 openSUSE 系统中安装了一些额外的大字号的 Terminus 字体包，因为默认安装的字体最大只有 16 点而我想要的是 32 点。然后将 `/etc/vconsole.conf` 的内容修改为：
|
||||
|
||||
```
|
||||
KEYMAP="us"
|
||||
FONT="ter-v32b"
|
||||
|
||||
```
|
||||
|
||||
下周我们还将学习一些更加酷的控制台小技巧，以及一些在控制台上运行的多媒体应用。
|
||||
|
||||
下周我们还将学习一些更加酷的控制台小技巧，以及一些在控制台上运行的[多媒体应用][4]。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -78,7 +79,7 @@ via: https://www.linux.com/learn/intro-to-linux/2018/1/how-change-your-linux-con
|
||||
|
||||
作者：[Carla Schroder][a]
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
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
|
||||
|
||||
@ -86,3 +87,4 @@ via: https://www.linux.com/learn/intro-to-linux/2018/1/how-change-your-linux-con
|
||||
[1]:http://jwilk.net/software/fbcat
|
||||
[2]:https://github.com/jwilk/fbcat/blob/master/fbgrab
|
||||
[3]:https://software.opensuse.org/package/console-setup
|
||||
[4]:https://linux.cn/article-9320-1.html
|
||||
@ -0,0 +1,66 @@
|
||||
开源软件二十年 —— 过去，现在，未来
|
||||
=================================================================
|
||||
|
||||
> 谨以此文纪念 “<ruby>开源软件<rt>open source software</rt></ruby>” 这个名词的二十周年纪念日，开源软件是怎么占有软件的主导地位的 ？以后会如何发展?
|
||||
|
||||
|
||||
|
||||
二十年以前，在 1998 年 2 月，“<ruby>开源<rt>open source</rt></ruby>” 这个词汇第一次出现在“软件”这一名词之前。不久之后，<ruby>开源的定义<rt>Open Source Definition</rt></ruby>（OSD） 这一文档被创建，并成为了撒播 <ruby>开放源代码促进会<rt>Open Source Initiative</rt></ruby>（OSI）的种子。正如 OSD 的作者 [Bruce Perens 所说][9]：
|
||||
|
||||
> “开源”是这场宣传自由软件的既有概念到商业软件，并将许可证化为一系列规则的运动的正式名称。
|
||||
|
||||
二十年后，我们能看到这一运动是非常成功的，甚至超出了当时参与这一活动的任何人的想象。 如今，开源软件无处不在。它是互联网和网络的基础。它为我们所有使用的电脑和移动设备，以及它们所连接的网络提供动力。没有它，云计算和新兴的物联网将不可能发展，甚至不可能出现。它使新的业务方式可以被测试和验证，还可以让像谷歌和 Facebook 这样的大公司在已有的基础之上继续攀登。
|
||||
|
||||
如任何人类的造物一样，它也有黑暗的一面。它也让反乌托邦的监视和必然导致的专制控制的出现成为了可能。它为犯罪分子提供了欺骗受害者的新的途径，还让匿名且大规模的欺凌得以存在。它让有破环性的狂热分子可以暗中组织而不会感到有何不便。这些都是开源的能力之下的黑暗投影。所有的人类工具都是如此，既可以养育人类，亦可以有害于人类。我们需要帮助下一代，让他们能争取无可取代的创新。就如 [费曼所说][10]：
|
||||
|
||||
> 每个人都掌握着一把开启天堂之门的钥匙，但这把钥匙亦能打开地狱之门。
|
||||
|
||||
开源运动已经渐渐成熟。我们讨论和理解它的方式也渐渐的成熟。如果说第一个十年是拥护与非议对立的十年，那么第二个十年就是接纳和适应并存的十年。
|
||||
|
||||
1. 在第一个十年里面，关键问题就是商业模型 —— “我怎样才能自由的贡献代码，且从中受益？” —— 之后，还有更多的人提出了有关管理的难题—— “我怎么才能参与进来，且不受控制 ?”
|
||||
2. 第一个十年的开源项目主要是替代现有的产品；而在第二个十年中，它们更多地是作为更大的解决方案的组成部分。
|
||||
3. 第一个十年的项目往往由非正式的个人组织进行；而在第二个十年中，它们经常由创建于各个项目上的机构经营。
|
||||
4. 第一个十年的开源开发者经常是投入于单一的项目，并经常在业余时间工作。 在第二个十年里，他们越来越多地受雇从事于一个专门的技术 —— 他们成了专业人员。
|
||||
5. 尽管开源一直被认为是提升软件自由度的一种方式，但在第一个十年中，这个运动与那些更喜欢使用“<ruby>自由软件<rt>free software</rt></ruby>”的人产生了冲突。在第二个十年里，随着开源运动的加速发展，这个冲突基本上被忽略了。
|
||||
|
||||
第三个十年会带来什么？
|
||||
|
||||
1. _更复杂的商业模式_ —— 主要的商业模式涉及到将很多开源组件整合而产生的复杂性的解决方案，特别是部署和扩展方面。 开源治理的需求将反映这一点。
|
||||
2. _开源拼图_ —— 开源项目将主要是一系列组件，彼此衔接构成组件堆栈。由此产生的解决方案将是开源组件的拼图。
|
||||
3. _项目族_ —— 越来越多的项目将由诸如 Linux Foundation 和 OpenStack 等联盟/行业协会以及 Apache 和 Software Freedom Conservancy 等机构主办。
|
||||
4. _专业通才_ —— 开源开发人员将越来越多地被雇来将诸多技术集成到复杂的解决方案里，这将有助于一系列的项目的开发。
|
||||
5. _软件自由度降低_ —— 随着新问题的出现，软件自由（将四项自由应用于用户和开发人员之间的灵活性）将越来越多地应用于识别解决方案是否适用于协作社区和独立部署人员。
|
||||
|
||||
2018 年，我将在全球各地的主题演讲中阐述这些内容。欢迎观看 [OSI 20 周年纪念全球巡演][11]！
|
||||
|
||||
_本文最初发表于 [Meshed Insights Ltd.][2] ， 已获转载授权，本文，以及我在 OSI 的工作，由 [Patreon patrons][3] 支持_
|
||||
|
||||
### 关于作者
|
||||
|
||||
Simon Phipps - 计算机工业和开源软件专家 Simon Phipps 创办了[公共软件公司][4]，这是一个欧洲开源项目的托管公司，以志愿者身份成为 OSI 的总裁，还是 The Document Foundation 的一名总监。 他的作品是由 [Patreon patrons][5] 赞助 —— 如果你想看更多的话，来做赞助人吧！ 在超过 30 年的职业生涯中，他一直在参与世界领先的战略层面的开发 ... [关于 Simon Phipps][6]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/2/open-source-20-years-and-counting
|
||||
|
||||
作者：[Simon Phipps][a]
|
||||
译者：[name1e5s](https://github.com/name1e5s)
|
||||
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/simonphipps
|
||||
[1]:https://opensource.com/article/18/2/open-source-20-years-and-counting?rate=TZxa8jxR6VBcYukor0FDsTH38HxUrr7Mt8QRcn0sC2I
|
||||
[2]:https://meshedinsights.com/2017/12/21/20-years-and-counting/
|
||||
[3]:https://patreon.com/webmink
|
||||
[4]:https://publicsoftware.eu/
|
||||
[5]:https://patreon.com/webmink
|
||||
[6]:https://opensource.com/users/simonphipps
|
||||
[7]:https://opensource.com/users/simonphipps
|
||||
[8]:https://opensource.com/user/12532/feed
|
||||
[9]:https://perens.com/2017/09/26/on-usage-of-the-phrase-open-source/
|
||||
[10]:https://www.brainpickings.org/2013/07/19/richard-feynman-science-morality-poem/
|
||||
[11]:https://opensource.org/node/905
|
||||
[12]:https://opensource.com/users/simonphipps
|
||||
[13]:https://opensource.com/users/simonphipps
|
||||
[14]:https://opensource.com/users/simonphipps
|
||||
@ -1,74 +0,0 @@
|
||||
translating by wyxplus
|
||||
How to price cryptocurrencies
|
||||
======
|
||||
|
||||
|
||||
|
||||
Predicting cryptocurrency prices is a fool's game, yet this fool is about to try. The drivers of a single cryptocurrency's value are currently too varied and vague to make assessments based on any one point. News is trending up on Bitcoin? Maybe there's a hack or an API failure that is driving it down at the same time. Ethereum looking sluggish? Who knows: Maybe someone will build a new smarter DAO tomorrow that will draw in the big spenders.
|
||||
|
||||
So how do you invest? Or, more correctly, on which currency should you bet?
|
||||
|
||||
The key to understanding what to buy or sell and when to hold is to use the tools associated with assessing the value of open-source projects. This has been said again and again, but to understand the current crypto boom you have to go back to the quiet rise of Linux.
|
||||
|
||||
Linux appeared on most radars during the dot-com bubble. At that time, if you wanted to set up a web server, you had to physically ship a Windows server or Sun Sparc Station to a server farm where it would do the hard work of delivering Pets.com HTML. At the same time, Linux, like a freight train running on a parallel path to Microsoft and Sun, would consistently allow developers to build one-off projects very quickly and easily using an OS and toolset that were improving daily. In comparison, then, the massive hardware and software expenditures associated with the status quo solution providers were deeply inefficient, and very quickly all of the tech giants that made their money on software now made their money on services or, like Sun, folded.
|
||||
|
||||
From the acorn of Linux an open-source forest bloomed. But there was one clear problem: You couldn't make money from open source. You could consult and you could sell products that used open-source components, but early builders built primarily for the betterment of humanity and not the betterment of their bank accounts.
|
||||
|
||||
Cryptocurrencies have followed the Linux model almost exactly, but cryptocurrencies have cash value. Therefore, when you're working on a crypto project you're not doing it for the common good or for the joy of writing free software. You're writing it with the expectation of a big payout. This, therefore, clouds the value judgements of many programmers. The same folks that brought you Python, PHP, Django and Node.js are back… and now they're programming money.
|
||||
|
||||
### Check the codebase
|
||||
|
||||
This year will be the year of great reckoning in the token sale and cryptocurrency space. While many companies have been able to get away with poor or unusable codebases, I doubt developers will let future companies get away with so much smoke and mirrors. It's safe to say we can [expect posts like this one detailing Storj's anemic codebase to become the norm][1] and, more importantly, that these commentaries will sink many so-called ICOs. Though massive, the money trough that is flowing from ICO to ICO is finite and at some point there will be greater scrutiny paid to incomplete work.
|
||||
|
||||
What does this mean? It means to understand cryptocurrency you have to treat it like a startup. Does it have a good team? Does it have a good product? Does the product work? Would someone want to use it? It's far too early to assess the value of cryptocurrency as a whole, but if we assume that tokens or coins will become the way computers pay each other in the future, this lets us hand wave away a lot of doubt. After all, not many people knew in 2000 that Apache was going to beat nearly every other web server in a crowded market or that Ubuntu instances would be so common that you'd spin them up and destroy them in an instant.
|
||||
|
||||
The key to understanding cryptocurrency pricing is to ignore the froth, hype and FUD and instead focus on true utility. Do you think that some day your phone will pay another phone for, say, an in-game perk? Do you expect the credit card system to fold in the face of an Internet of Value? Do you expect that one day you'll move through life splashing out small bits of value in order to make yourself more comfortable? Then by all means, buy and hold or speculate on things that you think will make your life better. If you don't expect the Internet of Value to improve your life the way the TCP/IP internet did (or you do not understand enough to hold an opinion), then you're probably not cut out for this. NASDAQ is always open, at least during banker's hours.
|
||||
|
||||
Still will us? Good, here are my predictions.
|
||||
|
||||
### The rundown
|
||||
|
||||
Here is my assessment of what you should look at when considering an "investment" in cryptocurrencies. There are a number of caveats we must address before we begin:
|
||||
|
||||
* Crypto is not a monetary investment in a real currency, but an investment in a pie-in-the-sky technofuture. That's right: When you buy crypto you're basically assuming that we'll all be on the deck of the Starship Enterprise exchanging them like Galactic Credits one day. This is the only inevitable future for crypto bulls. While you can force crypto into various economic models and hope for the best, the entire platform is techno-utopianist and assumes all sorts of exciting and unlikely things will come to pass in the next few years. If you have spare cash lying around and you like Star Wars, then you're golden. If you bought bitcoin on a credit card because your cousin told you to, then you're probably going to have a bad time.
|
||||
* Don't trust anyone. There is no guarantee and, in addition to offering the disclaimer that this is not investment advice and that this is in no way an endorsement of any particular cryptocurrency or even the concept in general, we must understand that everything I write here could be wrong. In fact, everything ever written about crypto could be wrong, and anyone who is trying to sell you a token with exciting upside is almost certainly wrong. In short, everyone is wrong and everyone is out to get you, so be very, very careful.
|
||||
* You might as well hold. If you bought when BTC was $18,000 you'd best just hold on. Right now you're in Pascal's Wager territory. Yes, maybe you're angry at crypto for screwing you, but maybe you were just stupid and you got in too high and now you might as well keep believing because nothing is certain, or you can admit that you were a bit overeager and now you're being punished for it but that there is some sort of bitcoin god out there watching over you. Ultimately you need to take a deep breath, agree that all of this is pretty freaking weird, and hold on.
|
||||
|
||||
|
||||
|
||||
Now on with the assessments.
|
||||
|
||||
**Bitcoin** - Expect a rise over the next year that will surpass the current low. Also expect [bumps as the SEC and other federal agencies][2] around the world begin regulating the buying and selling of cryptocurrencies in very real ways. Now that banks are in on the joke they're going to want to reduce risk. Therefore, the bitcoin will become digital gold, a staid, boring and volatility proof safe haven for speculators. Although all but unusable as a real currency, it's good enough for what we need it to do and we also can expect quantum computing hardware to change the face of the oldest and most familiar cryptocurrency.
|
||||
|
||||
**Ethereum** - Ethereum could sustain another few thousand dollars on its price as long as Vitalik Buterin, the creator, doesn't throw too much cold water on it. Like a remorseful Victor Frankenstein, Buterin tends to make amazing things and then denigrate them online, a sort of self-flagellation that is actually quite useful in a space full of froth and outright lies. Ethereum is the closest we've come to a useful cryptocurrency, but it is still the Raspberry Pi of distributed computing -- it's a useful and clever hack that makes it easy to experiment but no one has quite replaced the old systems with new distributed data stores or applications. In short, it's a really exciting technology, but nobody knows what to do with it.
|
||||
|
||||
![][3]
|
||||
|
||||
Where will the price go? It will hover around $1,000 and possibly go as high as $1,500 this year, but this is a principled tech project and not a store of value.
|
||||
|
||||
**Altcoins** - One of the signs of a bubble is when average people make statements like "I couldn't afford a Bitcoin so I bought a Litecoin." This is exactly what I've heard multiple times from multiple people and it's akin to saying "I couldn't buy hamburger so I bought a pound of sawdust instead. I think the kids will eat it, right?" Play at your own risk. Altcoins are a very useful low-risk play for many, and if you create an algorithm -- say to sell when the asset hits a certain level -- then you could make a nice profit. Further, most altcoins will not disappear overnight. I would honestly recommend playing with Ethereum instead of altcoins, but if you're dead set on it, then by all means, enjoy.
|
||||
|
||||
**Tokens** - This is where cryptocurrency gets interesting. Tokens require research, education and a deep understanding of technology to truly assess. Many of the tokens I've seen are true crapshoots and are used primarily as pump and dump vehicles. I won't name names, but the rule of thumb is that if you're buying a token on an open market then you've probably already missed out. The value of the token sale as of January 2018 is to allow crypto whales to turn a few cent per token investment into a 100X return. While many founders talk about the magic of their product and the power of their team, token sales are quite simply vehicles to turn 4 cents into 20 cents into a dollar. Multiply that by millions of tokens and you see the draw.
|
||||
|
||||
The answer is simple: find a few projects you like and lurk in their message boards. Assess if the team is competent and figure out how to get in very, very early. Also expect your money to disappear into a rat hole in a few months or years. There are no sure things, and tokens are far too bleeding-edge a technology to assess sanely.
|
||||
|
||||
You are reading this post because you are looking to maintain confirmation bias in a confusing space. That's fine. I've spoken to enough crypto-heads to know that nobody knows anything right now and that collusion and dirty dealings are the rule of the day. Therefore, it's up to folks like us to slowly buy surely begin to understand just what's going on and, perhaps, profit from it. At the very least we'll all get a new Linux of Value when we're all done.
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://techcrunch.com/2018/01/22/how-to-price-cryptocurrencies/
|
||||
|
||||
作者：[John Biggs][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://techcrunch.com/author/john-biggs/
|
||||
[1]:https://shitcoin.com/storj-not-a-dropbox-killer-1a9f27983d70
|
||||
[2]:http://www.businessinsider.com/bitcoin-price-cryptocurrency-warning-from-sec-cftc-2018-1
|
||||
[3]:https://tctechcrunch2011.files.wordpress.com/2018/01/vitalik-twitter-1312.png?w=525&h=615
|
||||
[4]:https://unsplash.com/photos/pElSkGRA2NU?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
[5]:https://unsplash.com/search/photos/cash?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
@ -0,0 +1,149 @@
|
||||
How writing can change your career for the better, even if you don't identify as a writer
|
||||
======
|
||||
Have you read Marie Kondo's book [The Life-Changing Magic of Tidying Up][1]? Or did you, like me, buy it and read a little bit and then add it to the pile of clutter next to your bed?
|
||||
|
||||
Early in the book, Kondo talks about keeping possessions that "spark joy." In this article, I'll examine ways writing about what we and other people are doing in the open source world can "spark joy," or at least how writing can improve your career in unexpected ways.
|
||||
|
||||
Because I'm a community manager and editor on Opensource.com, you might be thinking, "She just wants us to [write for Opensource.com][2]." And that is true. But everything I will tell you about why you should write is true, even if you never send a story in to Opensource.com. Writing can change your career for the better, even if you don't identify as a writer. Let me explain.
|
||||
|
||||
### How I started writing
|
||||
|
||||
Early in the first decade of my career, I transitioned from a customer service-related role at a tech publishing company into an editing role on Sys Admin Magazine. I was plugging along, happily laying low in my career, and then that all changed when I started writing about open source technologies and communities, and the people in them. But I did _not_ start writing voluntarily. The tl;dr: of it is that my colleagues at Linux New Media eventually talked me into launching our first blog on the [Linux Pro Magazine][3] site. And as it turns out, it was one of the best career decisions I've ever made. I would not be working on Opensource.com today had I not started writing about what other people in open source were doing all those years ago.
|
||||
|
||||
When I first started writing, my goal was to raise awareness of the company I worked for and our publications, while also helping raise the visibility of women in tech. But soon after I started writing, I began seeing unexpected results.
|
||||
|
||||
#### My network started growing
|
||||
|
||||
When I wrote about a person, an organization, or a project, I got their attention. Suddenly the people I wrote about knew who I was. And because I was sharing knowledge—that is to say, I wasn't being a critic—I'd generally become an ally, and in many cases, a friend. I had a platform and an audience, and I was sharing them with other people in open source.
|
||||
|
||||
#### I was learning
|
||||
|
||||
In addition to promoting our website and magazine and growing my network, the research and fact-checking I did when writing articles helped me become more knowledgeable in my field and improve my tech chops.
|
||||
|
||||
#### I started meeting more people IRL
|
||||
|
||||
When I went to conferences, I found that my blog posts helped me meet people. I introduced myself to people I'd written about or learned about during my research, and I met new people to interview. People started knowing who I was because they'd read my articles. Sometimes people were even excited to meet me because I'd highlighted them, their projects, or someone or something they were interested in. I had no idea writing could be so exciting and interesting away from the keyboard.
|
||||
|
||||
#### My conference talks improved
|
||||
|
||||
I started speaking at events about a year after launching my blog. A few years later, I started writing articles based on my talks prior to speaking at events. The process of writing the articles helps me organize my talks and slides, and it was a great way to provide "notes" for conference attendees, while sharing the topic with a larger international audience that wasn't at the event in person.
|
||||
|
||||
### What should you write about?
|
||||
|
||||
Maybe you're interested in writing, but you struggle with what to write about. You should write about two things: what you know, and what you don't know.
|
||||
|
||||
#### Write about what you know
|
||||
|
||||
Writing about what you know can be relatively easy. For example, a script you wrote to help automate part of your daily tasks might be something you don't give any thought to, but it could make for a really exciting article for someone who hates doing that same task every day. That could be a relatively quick, short, and easy article for you to write, and you might not even think about writing it. But it could be a great contribution to the open source community.
|
||||
|
||||
#### Write about what you don't know
|
||||
|
||||
Writing about what you don't know can be much harder and more time consuming, but also much more fulfilling and help your career. I've found that writing about what I don't know helps me learn, because I have to research it and understand it well enough to explain it.
|
||||
|
||||
> "When I write about a technical topic, I usually learn a lot more about it. I want to make sure my article is as good as it can be. So even if I'm writing about something I know well, I'll research the topic a bit more so I can make sure to get everything right." ~Jim Hall, FreeDOS project leader
|
||||
|
||||
For example, I wanted to learn about machine learning, and I thought narrowing down the topic would help me get started. My team mate Jason Baker suggested that I write an article on the [Top 3 machine learning libraries for Python][4], which gave me a focus for research.
|
||||
|
||||
The process of researching that article inspired another article, [3 cool machine learning projects using TensorFlow and the Raspberry Pi][5]. That article was also one of our most popular last year. I'm not an _expert_ on machine learning now, but researching the topic with writing an article in mind allowed me to give myself a crash course in the topic.
|
||||
|
||||
### Why people in tech write
|
||||
|
||||
Now let's look at a few benefits of writing that other people in tech have found. I emailed the Opensource.com writers' list and asked, and here's what writers told me.
|
||||
|
||||
#### Grow your network or your project community
|
||||
|
||||
Xavier Ho wrote for us for the first time last year ("[A programmer's cleaning guide for messy sensor data][6]"). He says: "I've been getting Twitter mentions from all over the world, including Spain, US, Australia, Indonesia, the UK, and other European countries. It shows the article is making some impact... This is the kind of reach I normally don't have. Hope it's really helping someone doing similar work!"
|
||||
|
||||
#### Help people
|
||||
|
||||
Writing about what other people are working on is a great way to help your fellow community members. Antoine Thomas, who wrote "[Linux helped me grow as a musician][7]", says, "I began to use open source years ago, by reading tutorials and documentation. That's why now I share my tips and tricks, experience or knowledge. It helped me to get started, so I feel that it's my turn to help others to get started too."
|
||||
|
||||
#### Give back to the community
|
||||
|
||||
[Jim Hall][8], who started the [FreeDOS project][9], says, "I like to write ... because I like to support the open source community by sharing something neat. I don't have time to be a program maintainer anymore, but I still like to do interesting stuff. So when something cool comes along, I like to write about it and share it."
|
||||
|
||||
#### Highlight your community
|
||||
|
||||
Emilio Velis wrote an article, "[Open hardware groups spread across the globe][10]", about projects in Central and South America. He explains, "I like writing about specific aspects of the open culture that are usually enclosed in my region (Latin America). I feel as if smaller communities and their ideas are hidden from the mainstream, so I think that creating this sense of broadness in participation is what makes some other cultures as valuable."
|
||||
|
||||
#### Gain confidence
|
||||
|
||||
[Don Watkins][11] is one of our regular writers and a [community moderator][12]. He says, "When I first started writing I thought I was an impostor, later I realized that many people feel that way. Writing and contributing to Opensource.com has been therapeutic, too, as it contributed to my self esteem and helped me to overcome feelings of inadequacy. … Writing has given me a renewed sense of purpose and empowered me to help others to write and/or see the valuable contributions that they too can make if they're willing to look at themselves in a different light. Writing has kept me younger and more open to new ideas."
|
||||
|
||||
#### Get feedback
|
||||
|
||||
One of our writers described writing as a feedback loop. He said that he started writing as a way to give back to the community, but what he found was that community responses give back to him.
|
||||
|
||||
Another writer, [Stuart Keroff][13] says, "Writing for Opensource.com about the program I run at school gave me valuable feedback, encouragement, and support that I would not have had otherwise. Thousands upon thousands of people heard about the Asian Penguins because of the articles I wrote for the website."
|
||||
|
||||
#### Exhibit expertise
|
||||
|
||||
Writing can help you show that you've got expertise in a subject, and having writing samples on well-known websites can help you move toward better pay at your current job, get a new role at a different organization, or start bringing in writing income.
|
||||
|
||||
[Jeff Macharyas][14] explains, "There are several ways I've benefitted from writing for Opensource.com. One, is the credibility I can add to my social media sites, resumes, bios, etc., just by saying 'I am a contributing writer to Opensource.com.' … I am hoping that I will be able to line up some freelance writing assignments, using my Opensource.com articles as examples, in the future."
|
||||
|
||||
### Where should you publish your articles?
|
||||
|
||||
That depends. Why are you writing?
|
||||
|
||||
You can always post on your personal blog, but if you don't already have a lot of readers, your article might get lost in the noise online.
|
||||
|
||||
Your project or company blog is a good option—again, you'll have to think about who will find it. How big is your company's reach? Or will you only get the attention of people who already give you their attention?
|
||||
|
||||
Are you trying to reach a new audience? A bigger audience? That's where sites like Opensource.com can help. We attract more than a million page views a month, and more than 700,000 unique visitors. Plus you'll work with editors who will polish and help promote your article.
|
||||
|
||||
We aren't the only site interested in your story. What are your favorite sites to read? They might want to help you share your story, and it's ok to pitch to multiple publications. Just be transparent about whether your article has been shared on other sites when working with editors. Occasionally, editors can even help you modify articles so that you can publish variations on multiple sites.
|
||||
|
||||
#### Do you want to get rich by writing? (Don't count on it.)
|
||||
|
||||
If your goal is to make money by writing, pitch your article to publications that have author budgets. There aren't many of them, the budgets don't tend to be huge, and you will be competing with experienced professional tech journalists who write seven days a week, 365 days a year, with large social media followings and networks. I'm not saying it can't be done—I've done it—but I am saying don't expect it to be easy or lucrative. It's not. (And frankly, I've found that nothing kills my desire to write much like having to write if I want to eat...)
|
||||
|
||||
A couple of people have asked me whether Opensource.com pays for content, or whether I'm asking someone to write "for exposure." Opensource.com does not have an author budget, but I won't tell you to write "for exposure," either. You should write because it meets a need.
|
||||
|
||||
If you already have a platform that meets your needs, and you don't need editing or social media and syndication help: Congratulations! You are privileged.
|
||||
|
||||
### Spark joy!
|
||||
|
||||
Most people don't know they have a story to tell, so I'm here to tell you that you probably do, and my team can help, if you just submit a proposal.
|
||||
|
||||
Most people—myself included—could use help from other people. Sites like Opensource.com offer one way to get editing and social media services at no cost to the writer, which can be hugely valuable to someone starting out in their career, someone who isn't a native English speaker, someone who wants help with their project or organization, and so on.
|
||||
|
||||
If you don't already write, I hope this article helps encourage you to get started. Or, maybe you already write. In that case, I hope this article makes you think about friends, colleagues, or people in your network who have great stories and experiences to share. I'd love to help you help them get started.
|
||||
|
||||
I'll conclude with feedback I got from a recent writer, [Mario Corchero][15], a Senior Software Developer at Bloomberg. He says, "I wrote for Opensource because you told me to :)" (For the record, I "invited" him to write for our [PyCon speaker series][16] last year.) He added, "And I am extremely happy about it—not only did it help me at my workplace by gaining visibility, but I absolutely loved it! The article appeared in multiple email chains about Python and was really well received, so I am now looking to publish the second :)" Then he [wrote for us][17] again.
|
||||
|
||||
I hope you find writing to be as fulfilling as we do.
|
||||
|
||||
You can connect with Opensource.com editors, community moderators, and writers in our Freenode [IRC][18] channel #opensource.com, and you can reach me and the Opensource.com team by email at [open@opensource.com][19].
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/2/career-changing-magic-writing
|
||||
|
||||
作者：[Rikki Endsley][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/rikki-endsley
|
||||
[1]:http://tidyingup.com/books/the-life-changing-magic-of-tidying-up-hc
|
||||
[2]:https://opensource.com/how-submit-article
|
||||
[3]:http://linuxpromagazine.com/
|
||||
[4]:https://opensource.com/article/17/2/3-top-machine-learning-libraries-python
|
||||
[5]:https://opensource.com/article/17/2/machine-learning-projects-tensorflow-raspberry-pi
|
||||
[6]:https://opensource.com/article/17/9/messy-sensor-data
|
||||
[7]:https://opensource.com/life/16/9/my-linux-story-musician
|
||||
[8]:https://opensource.com/users/jim-hall
|
||||
[9]:http://www.freedos.org/
|
||||
[10]:https://opensource.com/article/17/6/open-hardware-latin-america
|
||||
[11]:https://opensource.com/users/don-watkins
|
||||
[12]:https://opensource.com/community-moderator-program
|
||||
[13]:https://opensource.com/education/15/3/asian-penguins-Linux-middle-school-club
|
||||
[14]:https://opensource.com/users/jeffmacharyas
|
||||
[15]:https://opensource.com/article/17/5/understanding-datetime-python-primer
|
||||
[16]:https://opensource.com/tags/pycon
|
||||
[17]:https://opensource.com/article/17/9/python-logging
|
||||
[18]:https://opensource.com/article/16/6/getting-started-irc
|
||||
[19]:mailto:open@opensource.com
|
||||
@ -0,0 +1,47 @@
|
||||
Why an involved user community makes for better software
|
||||
======
|
||||
|
||||
|
||||
Imagine releasing a major new infrastructure service based on open source software only to discover that the product you deployed had evolved so quickly that the documentation for the version you released is no longer available. At Bloomberg, we experienced this problem firsthand in our deployment of OpenStack. In late 2016, we spent six months testing and rolling out [Liberty][1] on our OpenStack environment. By that time, Liberty was about a year old, or two versions behind the latest build.
|
||||
|
||||
As our users started taking advantage of its new functionality, we found ourselves unable to solve a few tricky problems and to answer some detailed questions about its API. When we went looking for Liberty's documentation, it was nowhere to be found on the OpenStack website. Liberty, it turned out, had been labeled "end of life" and was no longer supported by the OpenStack developer community.
|
||||
|
||||
The disappearance wasn't intentional, rather the result of a development community that had not anticipated the real-world needs of users. The documentation was stored in the source branch along with the source code, and, as Liberty was superseded by newer versions, it had been deleted. Worse, in the intervening months, the documentation for the newer versions had been completely restructured, and there was no way to easily rebuild it in a useful form. And believe me, we tried.
|
||||
|
||||
The disappearance wasn't intentional, rather the result of a development community that had not anticipated the real-world needs of users. ]After consulting other users and our vendor, we found that OpenStack's development cadence of two releases per year had created some unintended, yet deeply frustrating, consequences. Older releases that were typically still widely in use were being superseded and effectively killed for the purposes of support.
|
||||
|
||||
Eventually, conversations took place between OpenStack users and developers that resulted in changes. Documentation was moved out of the source branch, and users can now build documentation for whatever version they're using—more or less indefinitely. The problem was solved. (I'm especially indebted to my colleague [Chris Morgan][2], who was knee-deep in this effort and first wrote about it in detail for the [OpenStack Superuser blog][3].)
|
||||
|
||||
Many other enterprise users were in the same boat as Bloomberg—running older versions of OpenStack that are three or four versions behind the latest build. There's a good reason for that: On average it takes a reasonably large enterprise about six months to qualify, test, and deploy a new version of OpenStack. And, from my experience, this is generally true of most open source infrastructure projects.
|
||||
|
||||
For most of the past decade, companies like Bloomberg that adopted open source software relied on distribution vendors to incorporate, test, verify, and support much of it. These vendors provide long-term support (LTS) releases, which enable enterprise users to plan for upgrades on a two- or three-year cycle, knowing they'll still have support for a year or two, even if their deployment schedule slips a bit (as they often do). In the past few years, though, infrastructure software has advanced so rapidly that even the distribution vendors struggle to keep up. And customers of those vendors are yet another step removed, so many are choosing to deploy this type of software without vendor support.
|
||||
|
||||
Losing vendor support also usually means there are no LTS releases; OpenStack, Kubernetes, and Prometheus, and many more, do not yet provide LTS releases of their own. As a result, I'd argue that healthy interaction between the development and user community should be high on the list of considerations for adoption of any open source infrastructure. Do the developers building the software pay attention to the needs—and frustrations—of the people who deploy it and make it useful for their enterprise?
|
||||
|
||||
There is a solid model for how this should happen. We recently joined the [Cloud Native Computing Foundation][4], part of The Linux Foundation. It has a formal [end-user community][5], whose members include organizations just like us: enterprises that are trying to make open source software useful to their internal customers. Corporate members also get a chance to have their voices heard as they vote to select a representative to serve on the CNCF [Technical Oversight Committee][6]. Similarly, in the OpenStack community, Bloomberg is involved in the semi-annual Operators Meetups, where companies who deploy and support OpenStack for their own users get together to discuss their challenges and provide guidance to the OpenStack developer community.
|
||||
|
||||
The past few years have been great for open source infrastructure. If you're working for a large enterprise, the opportunity to deploy open source projects like the ones mentioned above has made your company more productive and more agile.
|
||||
|
||||
As large companies like ours begin to consume more open source software to meet their infrastructure needs, they're going to be looking at a long list of considerations before deciding what to use: license compatibility, out-of-pocket costs, and the health of the development community are just a few examples. As a result of our experiences, we'll add the presence of a vibrant and engaged end-user community to the list.
|
||||
|
||||
Increased reliance on open source infrastructure projects has also highlighted a key problem: People in the development community have little experience deploying the software they work on into production environments or supporting the people who use it to get things done on a daily basis. The fast pace of updates to these projects has created some unexpected problems for the people who deploy and use them. There are numerous examples I can cite where open source projects are updated so frequently that new versions will, usually unintentionally, break backwards compatibility.
|
||||
|
||||
As open source increasingly becomes foundational to the operation of so many enterprises, this cannot be allowed to happen, and members of the user community should assert themselves accordingly and press for the creation of formal representation. In the end, the software can only be better.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/2/important-conversation
|
||||
|
||||
作者：[Kevin P.Fleming][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/kpfleming
|
||||
[1]:https://releases.openstack.org/liberty/
|
||||
[2]:https://www.linkedin.com/in/mihalis68/
|
||||
[3]:http://superuser.openstack.org/articles/openstack-at-bloomberg/
|
||||
[4]:https://www.cncf.io/
|
||||
[5]:https://www.cncf.io/people/end-user-community/
|
||||
[6]:https://www.cncf.io/people/technical-oversight-committee/
|
||||
@ -0,0 +1,181 @@
|
||||
in which the cost of structured data is reduced
|
||||
======
|
||||
Last year I got the wonderful opportunity to attend [RacketCon][1] as it was hosted only 30 minutes away from my home. The two-day conference had a number of great talks on the first day, but what really impressed me was the fact that the entire second day was spent focusing on contribution. The day started out with a few 15- to 20-minute talks about how to contribute to a specific codebase (including that of Racket itself), and after that people just split off into groups focused around specific codebases. Each table had maintainers helping guide other folks towards how to work with the codebase and construct effective patch submissions.
|
||||
|
||||
![lensmen chronicles][2]
|
||||
|
||||
I came away from the conference with a great sense of appreciation for how friendly and welcoming the Racket community is, and how great Racket is as a swiss-army-knife type tool for quick tasks. (Not that it's unsuitable for large projects, but I don't have the opportunity to start any new large projects very frequently.)
|
||||
|
||||
The other day I wanted to generate colored maps of the world by categorizing countries interactively, and Racket seemed like it would fit the bill nicely. The job is simple: show an image of the world with one country selected; when a key is pressed, categorize that country, then show the map again with all categorized countries colored, and continue with the next country selected.
|
||||
|
||||
### GUIs and XML
|
||||
|
||||
I have yet to see a language/framework more accessible and straightforward out of the box for drawing1. Here's the entry point which sets up state and then constructs a canvas that handles key input and display:
|
||||
```
|
||||
(define (main path)
|
||||
(let ([frame (new frame% [label "World color"])]
|
||||
[categorizations (box '())]
|
||||
[doc (call-with-input-file path read-xml/document)])
|
||||
(new (class canvas%
|
||||
(define/override (on-char event)
|
||||
(handle-key this categorizations (send event get-key-code)))
|
||||
(super-new))
|
||||
[parent frame]
|
||||
[paint-callback (draw doc categorizations)])
|
||||
(send frame show #t)))
|
||||
|
||||
```
|
||||
|
||||
While the class system is not one of my favorite things about Racket (most newer code seems to avoid it in favor of [generic interfaces][3] in the rare case that polymorphism is truly called for), the fact that classes can be constructed in a light-weight, anonymous way makes it much less onerous than it could be. This code sets up all mutable state in a [`box`][4] which you use in the way you'd use a `ref` in ML or Clojure: a mutable wrapper around an immutable data structure.
|
||||
|
||||
The world map I'm using is [an SVG of the Robinson projection][5] from Wikipedia. If you look closely there's a call to bind `doc` that calls [`call-with-input-file`][6] with [`read-xml/document`][7] which loads up the whole map file's SVG; just about as easily as you could ask for.
|
||||
|
||||
The data you get back from `read-xml/document` is in fact a [document][8] struct, which contains an `element` struct containing `attribute` structs and lists of more `element` structs. All very sensible, but maybe not what you would expect in other dynamic languages like Clojure or Lua where free-form maps reign supreme. Racket really wants structure to be known up-front when possible, which is one of the things that help it produce helpful error messages when things go wrong.
|
||||
|
||||
Here's how we handle keyboard input; we're displaying a map with one country highlighted, and `key` here tells us what the user pressed to categorize the highlighted country. If that key is in the `categories` hash then we put it into `categorizations`.
|
||||
```
|
||||
(define categories #hash((select . "eeeeff")
|
||||
(#\1 . "993322")
|
||||
(#\2 . "229911")
|
||||
(#\3 . "ABCD31")
|
||||
(#\4 . "91FF55")
|
||||
(#\5 . "2439DF")))
|
||||
|
||||
(define (handle-key canvas categorizations key)
|
||||
(cond [(equal? #\backspace key) (swap! categorizations cdr)]
|
||||
[(member key (dict-keys categories)) (swap! categorizations (curry cons key))]
|
||||
[(equal? #\space key) (display (unbox categorizations))])
|
||||
(send canvas refresh))
|
||||
|
||||
```
|
||||
|
||||
### Nested updates: the bad parts
|
||||
|
||||
Finally once we have a list of categorizations, we need to apply it to the map document and display. We apply a [`fold`][9] reduction over the XML document struct and the list of country categorizations (plus `'select` for the country that's selected to be categorized next) to get back a "modified" document struct where the proper elements have the style attributes applied for the given categorization, then we turn it into an image and hand it to [`draw-pict`][10]:
|
||||
```
|
||||
|
||||
(define (update original-doc categorizations)
|
||||
(for/fold ([doc original-doc])
|
||||
([category (cons 'select (unbox categorizations))]
|
||||
[n (in-range (length (unbox categorizations)) 0 -1)])
|
||||
(set-style doc n (style-for category))))
|
||||
|
||||
(define ((draw doc categorizations) _ context)
|
||||
(let* ([newdoc (update doc categorizations)]
|
||||
[xml (call-with-output-string (curry write-xml newdoc))])
|
||||
(draw-pict (call-with-input-string xml svg-port->pict) context 0 0)))
|
||||
|
||||
```
|
||||
|
||||
The problem is in that pesky `set-style` function. All it has to do is reach deep down into the `document` struct to find the `n`th `path` element (the one associated with a given country), and change its `'style` attribute. It ought to be a simple task. Unfortunately this function ends up being anything but simple:
|
||||
```
|
||||
|
||||
(define (set-style doc n new-style)
|
||||
(let* ([root (document-element doc)]
|
||||
[g (list-ref (element-content root) 8)]
|
||||
[paths (element-content g)]
|
||||
[path (first (drop (filter element? paths) n))]
|
||||
[path-num (list-index (curry eq? path) paths)]
|
||||
[style-index (list-index (lambda (x) (eq? 'style (attribute-name x)))
|
||||
(element-attributes path))]
|
||||
[attr (list-ref (element-attributes path) style-index)]
|
||||
[new-attr (make-attribute (source-start attr)
|
||||
(source-stop attr)
|
||||
(attribute-name attr)
|
||||
new-style)]
|
||||
[new-path (make-element (source-start path)
|
||||
(source-stop path)
|
||||
(element-name path)
|
||||
(list-set (element-attributes path)
|
||||
style-index new-attr)
|
||||
(element-content path))]
|
||||
[new-g (make-element (source-start g)
|
||||
(source-stop g)
|
||||
(element-name g)
|
||||
(element-attributes g)
|
||||
(list-set paths path-num new-path))]
|
||||
[root-contents (list-set (element-content root) 8 new-g)])
|
||||
(make-document (document-prolog doc)
|
||||
(make-element (source-start root)
|
||||
(source-stop root)
|
||||
(element-name root)
|
||||
(element-attributes root)
|
||||
root-contents)
|
||||
(document-misc doc))))
|
||||
|
||||
```
|
||||
|
||||
The reason for this is that while structs are immutable, they don't support functional updates. Whenever you're working with immutable data structures, you want to be able to say "give me a new version of this data, but with field `x` replaced by the value of `(f (lookup x))`". Racket can [do this with dictionaries][11] but not with structs2. If you want a modified version you have to create a fresh one3.
|
||||
|
||||
### Lenses to the rescue?
|
||||
|
||||
![first lensman][12]
|
||||
|
||||
When I brought this up in the `#racket` channel on Freenode, I was helpfully pointed to the 3rd-party [Lens][13] library. Lenses are a general-purpose way of composing arbitrarily nested lookups and updates. Unfortunately at this time there's [a flaw][14] preventing them from working with `xml` structs, so it seemed I was out of luck.
|
||||
|
||||
But then I was pointed to [X-expressions][15] as an alternative to structs. The [`xml->xexpr`][16] function turns the structs into a deeply-nested list tree with symbols and strings in it. The tag is the first item in the list, followed by an associative list of attributes, then the element's children. While this gives you fewer up-front guarantees about the structure of the data, it does work around the lens issue.
|
||||
|
||||
For this to work, we need to compose a new lens based on the "path" we want to use to drill down into the `n`th country and its `style` attribute. The [`lens-compose`][17] function lets us do that. Note that the order here might be backwards from what you'd expect; it works deepest-first (the way [`compose`][18] works for functions). Also note that defining one lens gives us the ability to both get nested values (with [`lens-view`][19]) and update them.
|
||||
```
|
||||
(define (style-lens n)
|
||||
(lens-compose (dict-ref-lens 'style)
|
||||
second-lens
|
||||
(list-ref-lens (add1 (* n 2)))
|
||||
(list-ref-lens 10)))
|
||||
```
|
||||
|
||||
Our `<path>` XML elements are under the 10th item of the root xexpr, (hence the [`list-ref-lens`][20] with 10) and they are interspersed with whitespace, so we have to double `n` to find the `<path>` we want. The [`second-lens`][21] call gets us to that element's attribute alist, and [`dict-ref-lens`][22] lets us zoom in on the `'style` key out of that alist.
|
||||
|
||||
Once we have our lens, it's just a matter of replacing `set-style` with a call to [`lens-set`][23] in our `update` function we had above, and then we're off:
|
||||
```
|
||||
(define (update doc categorizations)
|
||||
(for/fold ([d doc])
|
||||
([category (cons 'select (unbox categorizations))]
|
||||
[n (in-range (length (unbox categorizations)) 0 -1)])
|
||||
(lens-set (style-lens n) d (list (style-for category)))))
|
||||
```
|
||||
|
||||
![second stage lensman][24]
|
||||
|
||||
Often times the trade-off between freeform maps/hashes vs structured data feels like one of convenience vs long-term maintainability. While it's unfortunate that they can't be used with the `xml` structs4, lenses provide a way to get the best of both worlds, at least in some situations.
|
||||
|
||||
The final version of the code clocks in at 51 lines and is is available [on GitLab][25].
|
||||
|
||||
๛
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://technomancy.us/185
|
||||
|
||||
作者：[Phil Hagelberg][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://technomancy.us/
|
||||
[1]:https://con.racket-lang.org/
|
||||
[2]:https://technomancy.us/i/chronicles-of-lensmen.jpg
|
||||
[3]:https://docs.racket-lang.org/reference/struct-generics.html
|
||||
[4]:https://docs.racket-lang.org/reference/boxes.html?q=box#%28def._%28%28quote._~23~25kernel%29._box%29%29
|
||||
[5]:https://commons.wikimedia.org/wiki/File:BlankMap-World_gray.svg
|
||||
[6]:https://docs.racket-lang.org/reference/port-lib.html#(def._((lib._racket%2Fport..rkt)._call-with-input-string))
|
||||
[7]:https://docs.racket-lang.org/xml/index.html?q=read-xml#%28def._%28%28lib._xml%2Fmain..rkt%29._read-xml%2Fdocument%29%29
|
||||
[8]:https://docs.racket-lang.org/xml/#%28def._%28%28lib._xml%2Fmain..rkt%29._document%29%29
|
||||
[9]:https://docs.racket-lang.org/reference/for.html?q=for%2Ffold#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._for%2Ffold%29%29
|
||||
[10]:https://docs.racket-lang.org/pict/Rendering.html?q=draw-pict#%28def._%28%28lib._pict%2Fmain..rkt%29._draw-pict%29%29
|
||||
[11]:https://docs.racket-lang.org/reference/dicts.html?q=dict-update#%28def._%28%28lib._racket%2Fdict..rkt%29._dict-update%29%29
|
||||
[12]:https://technomancy.us/i/first-lensman.jpg
|
||||
[13]:https://docs.racket-lang.org/lens/lens-guide.html
|
||||
[14]:https://github.com/jackfirth/lens/issues/290
|
||||
[15]:https://docs.racket-lang.org/pollen/second-tutorial.html?q=xexpr#%28part._.X-expressions%29
|
||||
[16]:https://docs.racket-lang.org/xml/index.html?q=xexpr#%28def._%28%28lib._xml%2Fmain..rkt%29._xml-~3exexpr%29%29
|
||||
[17]:https://docs.racket-lang.org/lens/lens-reference.html#%28def._%28%28lib._lens%2Fcommon..rkt%29._lens-compose%29%29
|
||||
[18]:https://docs.racket-lang.org/reference/procedures.html#%28def._%28%28lib._racket%2Fprivate%2Flist..rkt%29._compose%29%29
|
||||
[19]:https://docs.racket-lang.org/lens/lens-reference.html?q=lens-view#%28def._%28%28lib._lens%2Fcommon..rkt%29._lens-view%29%29
|
||||
[20]:https://docs.racket-lang.org/lens/lens-reference.html?q=lens-view#%28def._%28%28lib._lens%2Fdata%2Flist..rkt%29._list-ref-lens%29%29
|
||||
[21]:https://docs.racket-lang.org/lens/lens-reference.html?q=lens-view#%28def._%28%28lib._lens%2Fdata%2Flist..rkt%29._second-lens%29%29
|
||||
[22]:https://docs.racket-lang.org/lens/lens-reference.html?q=lens-view#%28def._%28%28lib._lens%2Fdata%2Fdict..rkt%29._dict-ref-lens%29%29
|
||||
[23]:https://docs.racket-lang.org/lens/lens-reference.html?q=lens-view#%28def._%28%28lib._lens%2Fcommon..rkt%29._lens-set%29%29
|
||||
[24]:https://technomancy.us/i/second-stage-lensman.jpg
|
||||
[25]:https://gitlab.com/technomancy/world-color/blob/master/world-color.rkt
|
||||
79
translated/talk/20180122 How to price cryptocurrencies.md
Normal file
79
translated/talk/20180122 How to price cryptocurrencies.md
Normal file
@ -0,0 +1,79 @@
|
||||
如何为数字货币定价
|
||||
======
|
||||
|
||||
|
||||
|
||||
预测数字货币价格是一场愚人游戏，但我即将尝试。单一数字货币价值的驱动因素目前太多，而且含糊不清，无法根据任何一点进行评估。或许新闻正报道说比特币呈上升趋势，但与此同时，有黑客攻击或是交易所API错误，就让比特币的价格下跌。以太坊看起来不够智能？谁知道呢，也许第二天就建立一个新的更智能的DAO（译者注：区块链上，基于激励的经济协调机制，以代码作为表达，通过互联网进行传输，允许人们参与数字企业的风险&回报（分配），代币创建了DAO参与者之间的经济链接）将吸引大量参与者。
|
||||
|
||||
那么，您该如何投资呢？又或是更准确的讲，您下注在哪种数字货币上呢？
|
||||
|
||||
|
||||
理解什么时候买卖和持有数字货币，关键是使用与评估开源项目价值的相关工具。这已经一次又一次地被提及了，但是为了理解当前数字货币的快速发展，您必须回到Linux悄然兴起的时候。
|
||||
|
||||
互联网泡沫期间，Linux出现在大众视野中。那时候，如果您想建立一个Web服务器，您必须将一台Windows服务器或者Sun Sparc工作站运送到一个服务器群组，在那里它将为传送Pets.com(译者注:在线宠物商店,借着互联网繁荣的机会崛起，在互联网泡沫破裂时倒闭)的HTML页面做出努力。与此同时，Linux就像运行在微软和Sun平行路径上的货运列车一样，可以让开发人员使用日新月异的操作系统和工具集，快速，轻松地构建一次性项目。相比之下，解决方案提供商的花费比软硬件支出少得多，很快，所有科技巨头的业务由软件转向了服务提供，例如Sun公司。
|
||||
|
||||
Linux的开始促使整个开源市场蓬勃发展起来。但是有一个关键的问题，您无法从开源软件中赚钱。但您可以提供服务，也可以销售使用开源组件的产品，但早期开源者主要是为了提升自我，而不是为了赚钱。
|
||||
|
||||
数字货币几乎完全遵循Linux道路，但数字货币具有一定货币价值。因此，当您在为一个区块链项目工作时，您不是为了公共利益，也不是为了编写自由软件的乐趣，而是您写它的时候期望得到一大笔钱。因此，这掩盖了许多程序员的价值判断。带给您Python，PHP，Django和Node.js的人回来了...而现在他们正在通过编程赚钱。
|
||||
|
||||
### 审查代码库
|
||||
|
||||
今年将是代币销售和数字货币领域大清算的一年。虽然许多公司已经能够摆脱糟糕的或不可用的代码库，但我怀疑开发人员是否能让未来的公司摆脱虚假东西。可以肯定地说，我们可以期待[像这样详细描述Storj代码库不足之处的文章成为规范][1]，这些评论会让许多所谓的“ICOs”（译者注：代币发行融资）陷入困境。虽然规模巨大，但ICO的资金渠道是有限的，在某种程度上会对不完整的项目进行更严格的审查。
|
||||
|
||||
这是什么意思呢？这意味着要了解数字货币，您必须像对待创业公司那样对待它。您要看它是否有一个好团队？它是否是一个好产品？是否能运作？会有人想要使用它吗？现在评估整个数字货币的价值还为时过早，但如果我们假设代币将成为未来计算机互相支付的方式，这就让我们摆脱了许多疑问。毕竟，2000年没有多少人知道Apache会在一个竞争激烈的市场上，几乎击败其他所有的Web服务器，或者像Ubuntu一样常见以至于可以立即将它们拆分并摧毁它们。
|
||||
|
||||
理解数字货币价值的关键是忽视泡沫，炒作、恐惧、迷惑和怀疑心理，而是关注其真正的效用。您认为有一天您的手机会为另外一个手机付款，比如游戏内的额外费用吗？ 您是否认为信用卡系统会在互联网出现后消失？您是否期望有一天，在生活中花费一点点钱，让自己过得更加舒适？然后，通过一切手段，购买并持有您认为将来可能会使您的生活过得更舒适的东西。如果您认为通过TCP/IP互联网的方式并不能够改善您的生活（或是您对其没有足够的了解），那么您可能就不会关注这些。纳斯达克总是开放的，至少在银行的营业时间。
|
||||
|
||||
好的，下面是我的预测。
|
||||
|
||||
### 预测
|
||||
|
||||
以下是我在考虑加密货币的“投资”时应该考虑的事项评估。在我们开始之前，先讲下注意事项：
|
||||
|
||||
* 数字货币不是真正的货币投资，而是投资在未来的技术。这就好比：当您购买数字货币时，我们像是在星舰的甲板上交换“信用”(译者注:《星球大战》电影中的一种货币)一般。 这是数字货币的唯一不可避免的未来。虽然您可以强制将数字货币附加到各种经济模式中，对其抱有乐观的态度，整个平台是技术乌托邦，并假设各种令人兴奋和不可能的事情将在未来几年来到。如果您有多余的现金，您喜欢《星球大战》，那么您就可以投资“黄金”。如果您的兄弟告诉您相关信息，结果您用信用卡买了比特币，那么您可能会要度过一段啃馒头的时间。
|
||||
|
||||
* 不要相信任何人。没有担保，除了提供不是投资建议的免责声明，而且这绝不是对任何特定数字货币的背书，甚至是普遍概念，但我们必须明白，我在这里写的任何东西都可能是错误的。事实上，任何关于数字货币的文章都可能是错误的，任何试图卖给您吹得天花乱坠的代币的人，几乎肯定是骗子。总之，每个人都是错的，每个人都想要得到您的钱，所以要非常、非常小心。
|
||||
|
||||
* 您也可以持有。如果您是在18000美元的价位买的比特币，您最好还是继续持有下去。 现在您就好像正处于帕斯卡赌注。（译者注：论述:我不知道上帝是否存在，如果他不存在，作为无神论者没有任何好处，但是如果他存在，作为无神论者我将有很大的坏处。所以，宁愿相信上帝存在）是的，也许您因为数字货币让您赔钱而生气，但也许您只是因为您的愚蠢和自大,但现在您不妨保持信仰,因为没有什么是必然的,或者您可以承认您是有点过于热切的。虽然现在您被惩罚,但要相信有比特币之神在注视着您。最终您需要深吸一口气，同意这一切都相当怪异，并坚持下去。
|
||||
|
||||
现在回过头来评估数字货币。
|
||||
|
||||
**比特币** - 预计明年的涨幅将超过目前的低点。此外，[世界各地的证券交易委员会和其他联邦机构][2]也会开始以实际行动调整加密货币的买卖。现在银行开玩笑说，他们想要降低数字货币的风险。因此，比特币将成为数字黄金，成为投机者稳定，乏味但充满波动的避风港。尽管所有都不能用作真正的货币，但对于我们所需要的东西来说，这已经足够了，我们也可以期待量子计算的产品去改变最古老，最熟悉的加密货币的面貌。
|
||||
|
||||
|
||||
**以太坊** - 只要创造者Vitalik Buterin不再继续泼冷水，以太坊在价格上可以维持在上千美元。像一个懊悔的维克多·弗兰肯斯坦（Victor Frankenstein）(译者注：来自《维克多·弗兰肯斯坦》电影的一名角色)，Buterin倾向于做出惊人的事情，然后在网上诋毁他们，这种自我鞭策在充满泡沫和谎言的空间中实际上是非常有用的。以太坊是最接近我们有用的加密货币，但它本质上仍然是分布式应用。这是一个很有用，很聪明的方法，可以很容易地进行实验，但是，没有人用新的分布式数据存储或应用程序取代旧系统。总之，这是一个非常令人兴奋的技术，但是还没有人知道该用它做什么。
|
||||
|
||||
|
||||
![][3]
|
||||
|
||||
以太坊的价格将何去何从？它将徘徊在1000美元左右，今年可能高达1500美元，但这是一个原则性的科技项目，但却不是一个保值产品。
|
||||
|
||||
**竞争币**(译者注：除比特币，以太币之外的所有的数字币) - 泡沫的标志之一是当普通人说“我买不起比特币，所以我买了莱特币”这样的话时。这正是我从许多人那里听到的，就好像说“我买不起汉堡，所以我买了一斤木屑，我想孩子们会吃的，对不对？”那您要自担风险。竞争币对于很多人来说是一个风险非常低游戏，就好比您根据一个算法创造出某个竞争币，在市值达到一定水平时卖出，那么您可以赚取一笔不错的利润。况且，大多数竞争币不会在一夜之间消失。 我诚实地推荐以太坊而不是竞争币，但是如果您死磕竞争币，那祝您玩得开心。
|
||||
|
||||
|
||||
**代币** - 这是数字货币变得有趣的地方。代币需要研究机构和高校对技术有深入的了解，才能真正的评估。我见过的许多代币都是一场赌博，价格暴涨暴跌。我不会给其命名，但是经验法则是，如果您在公开市场上买了一个代币，那么您可能已经错过了赚钱的机会。截至2018年1月，代币销售，庄家开始投资一个代币几美分，最后得到百倍的回报。虽然许多创始人谈论他们的产品的神奇之处和他们的团队的强大，但是就是为了单车变摩托，把价值4美分一个的代币升值为20美分，再升值成一美元。您将收益乘以数百万，就能看到它的吸引力了。
|
||||
|
||||
答案很简单：找到您喜欢的几个项目并潜藏在他们的社区中。评估团队是否有实力，并且很早就知道该如何进入。将钱投入后就当扔掉几个月或几年。但无法保证，因为代币理念太过超前，以至于无法对其评估。
|
||||
|
||||
|
||||
您正在阅读这篇文章，是因为您希望在这错综复杂的环境下得到一个方向。没关系，我已经跟许多数字货币创始人交谈，知道现在许多人不知道的事情，并且知道合谋和肮脏交易的准则。因此，像我们这样的人，要慢慢地分批购买，就会开始明白这究竟是怎么一回事，也许会从数字货币投资中获利。当数字货币的潜力被完全发掘，我们会得到一个像Linux一样的时代。
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://techcrunch.com/2018/01/22/how-to-price-cryptocurrencies/
|
||||
|
||||
作者：[John Biggs][a]
|
||||
译者：[wyxplus](https://github.com/wyxplus)
|
||||
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://techcrunch.com/author/john-biggs/
|
||||
[1]:https://shitcoin.com/storj-not-a-dropbox-killer-1a9f27983d70
|
||||
[2]:http://www.businessinsider.com/bitcoin-price-cryptocurrency-warning-from-sec-cftc-2018-1
|
||||
[3]:https://tctechcrunch2011.files.wordpress.com/2018/01/vitalik-twitter-1312.png?w=525&h=615
|
||||
[4]:https://unsplash.com/photos/pElSkGRA2NU?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
[5]:https://unsplash.com/search/photos/cash?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
@ -1,75 +0,0 @@
|
||||
开源软件二十年 —— 过去，现在，未来
|
||||
=================================================================
|
||||
|
||||
### 谨以此文纪念 “开源软件” 这个词的二十年纪念日，开源软件是怎么占有软件的主导地位的 ？以后会如何发展?
|
||||
|
||||
|
||||
图片来自 : opensource.com
|
||||
|
||||
二十年以前，在 1998 年二月，“开源” 这个词汇第一次出现在软件之前。不久之后，如”开源的定义“（OSD）的作者 [Bruce Perens 所说][9], OSD 这一文档被创建，开放源代码促进会（ OSI ）的种子被播种。
|
||||
|
||||
> “开源”是宣传自由软件的既有概念到商业软件，并对使用一系列规则对许可证进行认证的活动的正式名称。
|
||||
|
||||
二十年后，我们能看到这一运动是非常成功的，甚至超出了当时参与这一活动的任何人的想象。 如今，开源软件无处不在。它是互联网和网络的基础。它为我们所有使用的电脑和移动设备，以及它们所连接的网络提供动力。没有它，云计算和新兴的物联网将不可能发展，甚至不可能出现。它使新的业务方式能被测试和验证，还可以让像谷歌和 Facebook 这样的大公司使用别人的成果继续发展。
|
||||
|
||||
如任何人类的创造物一样，它也有黑暗的一面。它也让反乌托邦的监视和必然导致的专制控制的出现成为了可能。它为犯罪分子提供欺骗受害者的新的途径，还让匿名且大规模的欺凌得以存在。它让有破环性的狂热分子可以暗中组织而不会感到有何不便。这些都是开源的能力之下的黑暗投影。所有的人类工具都是如此，既可以养育人类，亦可以有害于人类。我们需要帮助下一代，让他们能争取无可取代的创新。就如 [费曼所说][10]，
|
||||
|
||||
> 每个人都掌握着一把开启天堂之门的钥匙，但这把钥匙亦能打开地狱之门。
|
||||
|
||||
开源运动已经渐渐成熟。我们讨论和理解它的方式也渐渐的成熟。如果说第一个十年拥护与非议对立的十年，那么第二个十年就是接纳和适应并存的十年。
|
||||
|
||||
1. 在第一个十年里面，关键问题就是商业模型 - “我怎样才能自由的贡献代码，且从中受益？” - 之后，还有更多的人提出了有关管理的难题- “我怎么才能参与进来，且不受控制 ?”
|
||||
|
||||
2. 第一个十年的开源项目主要是替代现有的产品; 在第二个十年中，它们更多地是作为更大的解决方案的组成部分。
|
||||
|
||||
3. 第一个十年的项目往往由非正式的个人组织进行; 在第二个十年中，它们经常由逐个项目地创建的机构经营。
|
||||
|
||||
4. 第一个十年的开源开发人员经常是投入于单一的项目，并经常在业余时间工作。 在第二个十年里，他们越来越多地受雇于一个专门的技术 —— 他们成了专业人员。
|
||||
|
||||
5. 尽管开源一直被认为是提升软件自由度的一种方式，但在第一个十年中，这个运动与那些更喜欢使用“自由软件”的人产生了冲突。在第二个十年里，随着开源运动的加速发展，这个冲突基本上被忽略了。
|
||||
|
||||
第三个十年会带来什么？
|
||||
|
||||
1. _更复杂的商业模式_ - 主要的商业模式将通过整合很多开源的，特别是部署和扩展，那部分的开源软件，从而产生的复杂的解决方案。 管理的需求将反映这一点。
|
||||
|
||||
2. _开源拼图_ - 开源项目将主要是一堆组件。 由此产生的解决方案将是开源组建的拼图。
|
||||
|
||||
3. _项目族_ - 越来越多的项目将由诸如 Linux Foundation 和 OpenStack 等联盟/行业协会以及 Apache 和 Software Freedom Conservancy 等机构主办。
|
||||
|
||||
4. _专业通才_ - 开源开发人员将越来越多地被雇来将诸多技术集成到复杂的解决方案里，这将有助于一系列的项目的开发。
|
||||
|
||||
5. _软件自由度降低_ - 随着新问题的出现，软件自由（将四项自由应用于用户和开发人员之间的灵活性）将越来越多地应用于识别适用于协作社区和独立部署人员的解决方案。
|
||||
|
||||
2018年，我将在全球各地的主题演讲中阐述这些内容。欢迎观看 [OSI 20周年纪念全球巡演][11]！
|
||||
|
||||
_本文最初发表于 [Meshed Insights Ltd.][2] ， 已获转载授权，本文，以及我在 OSI 的工作，由 [Patreon patrons][3] 支持_
|
||||
|
||||
### 关于作者
|
||||
|
||||
[][12] Simon Phipps - 计算机工业和开源软件专家Simon Phipps创办了[公共软件公司][4]，一个欧洲开源项目主管，志愿成为 OSI 的总裁，还是The Document Foundation的一名主管。 他的作品是由 [Patreon patrons][5] 赞助 - 如果你想看更多的话，来做赞助人吧！ 在超过30年的职业生涯中，他一直在参与世界领先的战略层面的开发...[关于 Simon Phipps][6][关于我][7]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/2/open-source-20-years-and-counting
|
||||
|
||||
作者：[Simon Phipps ][a]
|
||||
译者：[name1e5s](https://github.com/name1e5s)
|
||||
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/simonphipps
|
||||
[1]:https://opensource.com/article/18/2/open-source-20-years-and-counting?rate=TZxa8jxR6VBcYukor0FDsTH38HxUrr7Mt8QRcn0sC2I
|
||||
[2]:https://meshedinsights.com/2017/12/21/20-years-and-counting/
|
||||
[3]:https://patreon.com/webmink
|
||||
[4]:https://publicsoftware.eu/
|
||||
[5]:https://patreon.com/webmink
|
||||
[6]:https://opensource.com/users/simonphipps
|
||||
[7]:https://opensource.com/users/simonphipps
|
||||
[8]:https://opensource.com/user/12532/feed
|
||||
[9]:https://perens.com/2017/09/26/on-usage-of-the-phrase-open-source/
|
||||
[10]:https://www.brainpickings.org/2013/07/19/richard-feynman-science-morality-poem/
|
||||
[11]:https://opensource.org/node/905
|
||||
[12]:https://opensource.com/users/simonphipps
|
||||
[13]:https://opensource.com/users/simonphipps
|
||||
[14]:https://opensource.com/users/simonphipps
|
||||
@ -1,11 +1,11 @@
|
||||
为初学者准备的 Linux ln 命令教程（5 个示例）
|
||||
======
|
||||
|
||||
当我们在命令行上工作时，您可能需要创建文件链接。这时，您可以可以借助一个专用命令，**ln**。本教程中，我们将基于此命令通过一些简明的例子展开讨论。在此之前，有必要明确，本教程所有测试都是基于 Ubuntu 16.04 设备开展的。
|
||||
当我们在命令行上工作时，您可能需要在文件之间创建链接。这时，您可以可以借助一个专用命令，**ln**。本教程中，我们将通过一些简单易理解的例子来讨论此工具的基础知识。在此之前，值得一提的是，本教程所有例子都已在 Ubuntu 16.04 上测试通过。
|
||||
|
||||
### Linux ln 命令
|
||||
|
||||
正如现在你所了解的，ln 命令能够让您链接文件。下面就是 ln 工具的语法（或者使用其他一些可行的语法）。
|
||||
正如你现在所了解的，ln 命令能够让您在文件之间创建链接。下面就是 ln 工具的语法（或者使用其他一些可行的语法）。
|
||||
|
||||
```
|
||||
ln [OPTION]... [-T] TARGET LINK_NAME (1st form)
|
||||
@ -16,32 +16,30 @@ ln [OPTION]... -t DIRECTORY TARGET... (4th form)
|
||||
|
||||
下面是 ln 工具 man 文档描述的内容：
|
||||
```
|
||||
在第一种形式下，创建名为 LINK_NAME 的链接目标。
|
||||
第二种形式为创建链接在当前目录。
|
||||
第三和第四中形式中，在 DIRECTORY 目录下创建链接目标。默认创建硬链接，字符链接需要 --symbolic 选项。默认创建硬链接，目标文件必须存在。字符链接可以保存任何文件。
|
||||
在第一种形式下，为 TARGET 创建一个叫 LINK_NAME 的链接。在第二种形式下，为 TARGET 在当前目录下创建一个链接（ LCTT 译注：创建的为同名链接）。在第三和第四中形式中，在 DIRECTORY 目录下为每一个 TARGET 创建链接。默认创建硬链接，符号链接需要 --symbolic 选项。默认创建的每一个目标（新链接的名字）都不能已经存在。当创建硬链接时，TARGET 文件必须存在。符号链接可以保存任意文本，如果之后解析，相对链接的解析与其父目录有关。
|
||||
```
|
||||
|
||||
同故宫下面问答风格的例子，可能会给你更好的理解。但是在此之前，建议您先了解 [软连接和硬链接的区别][1].
|
||||
通过下面问答风格的例子，可能会给你更好的理解。但是在此之前，建议您先了解 [硬链接和软链接的区别][1].
|
||||
|
||||
### Q1. 如何通过 ln 命令创建硬链接？
|
||||
### Q1. 如何使用 ln 命令创建硬链接？
|
||||
|
||||
这很简单，你只需要使用下面的 ln 命令：
|
||||
这很简单，你只需要像下面使用 ln 命令：
|
||||
|
||||
```
|
||||
ln [file] [hard-link-to-file]
|
||||
```
|
||||
|
||||
这里有一个示例：
|
||||
例如：
|
||||
|
||||
```
|
||||
ln test.txt test_hard_link.txt
|
||||
```
|
||||
|
||||
[![如何通过 ln 命令创建硬链接][2]][3]
|
||||
[![如何使用 ln 命令创建硬链接][2]][3]
|
||||
|
||||
如此，您便可以看见一个已经创建好了的硬链接，名为 test_hard_link.txt。
|
||||
如此，您便可以看见一个已经创建好的，名为 test_hard_link.txt 的硬链接。
|
||||
|
||||
### Q2. 如何通过 ln 命令创建软/字符链接？
|
||||
### Q2. 如何使用 ln 命令创建软/符号链接？
|
||||
|
||||
使用 -s 命令行选项
|
||||
|
||||
@ -49,33 +47,35 @@ ln test.txt test_hard_link.txt
|
||||
ln -s [file] [soft-link-to-file]
|
||||
```
|
||||
|
||||
这里有一个示例：
|
||||
例如：
|
||||
|
||||
```
|
||||
ln -s test.txt test_soft_link.txt
|
||||
```
|
||||
|
||||
[![如何通过 ln 命令创建软/字符链接][4]][5]
|
||||
[![如何使用 ln 命令创建软/符号链接][4]][5]
|
||||
|
||||
test_soft_link.txt 文件就是一个软/字符链接，被天蓝色文本 [标识][6]。
|
||||
test_soft_link.txt 文件就是一个软/符号链接，被天蓝色文本 [标识][6]。
|
||||
|
||||
### Q3. 如何通过 ln 命令删除既存的同名目标文件？
|
||||
### Q3. 如何使用 ln 命令删除既存的同名目标文件？
|
||||
|
||||
默认情况下，ln 不允许您在目标文件目录下创建同名链接。
|
||||
默认情况下，ln 不允许您在目标目录下创建已存在的链接。
|
||||
|
||||
[![ln 命令示例][7]][8]
|
||||
|
||||
然而，如果一定要这么做，您可以使用 **-f** 命令行选项忽视此行为。
|
||||
然而，如果一定要这么做，您可以使用 **-f** 命令行选项覆盖此行为。
|
||||
|
||||
[![如何通过 ln 命令创建软/字符链接][9]][10]
|
||||
[![如何使用 ln 命令创建软/符号链接][9]][10]
|
||||
|
||||
**贴士** : 如果您想忽略删除过程中所有的命令行交互，您可以使用 **-i** 选项。
|
||||
**贴士** : 如果您想在此删除过程中有所交互，您可以使用 **-i** 选项。
|
||||
|
||||
### Q4. 如何通过 ln 命令创建既存文件的同名备份？
|
||||
### Q4. 如何使用 ln 命令创建现有文件的同名备份？
|
||||
|
||||
如果您不想通过 ln 删除同名的既存文件，您可以让它为此文件创建备份。使用 **-b** 即可实现此效果。被创建的备份文件，会在其文件名结尾处包含一个（~） 字符标识。
|
||||
如果您不想 ln 删除同名的现有文件，您可以为这些文件创建备份。使用 **-b** 即可实现此效果，以这种方式创建的备份文件，会在其文件名结尾处包含一个波浪号（~）。
|
||||
|
||||
[![如何通过 ln 命令创建既存文件的同名备份][11]][12]
|
||||
[![如何使用 ln 命令创建现有文件的同名备份][11]][12]
|
||||
|
||||
### Q5. 如何在当前目录以外的其它目录创建链接？
|
||||
|
||||
使用 **-t** 选项指定一个文件目录（除了当前目录）。比如：
|
||||
|
||||
@ -83,11 +83,11 @@ test_soft_link.txt 文件就是一个软/字符链接，被天蓝色文本 [标
|
||||
ls test* | xargs ln -s -t /home/himanshu/Desktop/
|
||||
```
|
||||
|
||||
上述命令会为所有 test* 文件（当前目录下的 test* 文件）创建链接到桌面。
|
||||
上述命令会为所有 test* 文件（当前目录下的 test* 文件）创建链接，并放到桌面目录下。
|
||||
|
||||
### 总结
|
||||
|
||||
当然，**ln** 并不是日常必备命令，尤其对于新手。但是了解此命令益处良多，有备无患，万一它哪一天刚好可以拯救你。对于这个命令，我们已经讨论了一些实用的选项，更多详情请查询 [man 文档][13]。
|
||||
当然，尤其对于新手来说，**ln** 并不是日常必备命令。但是，这是一个有用的命令，因为你永远不知道它什么时候能够节省你一天的时间。对于这个命令，我们已经讨论了一些实用的选项，如果你已经完成了这些，可以查询 [man 文档][13] 来了解更多详情。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -95,7 +95,7 @@ via: https://www.howtoforge.com/linux-ln-command/
|
||||
|
||||
作者：[Himanshu Arora][a]
|
||||
译者：[CYLeft](https://github.com/CYLeft)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[Locez](https://github.com/locez)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user