Merge pull request #18787 from geekpi/translating

Translated

sources/tech/20200615 How to use Bash history commands.md

@@ -1,5 +1,5 @@
 [#]: collector: (lujun9972)
-[#]: translator: ( )
+[#]: translator: (geekpi)
 [#]: reviewer: ( )
 [#]: publisher: ( )
 [#]: url: ( )

sources/tech/20200616 How to loop forever in bash on Linux.md

@@ -1,147 +0,0 @@
-[#]: collector: (lujun9972)
-[#]: translator: (geekpi)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to loop forever in bash on Linux)
-[#]: via: (https://www.networkworld.com/article/3562576/how-to-loop-forever-in-bash-on-linux.html)
-[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
-
-How to loop forever in bash on Linux
-======
-
-[tine ivanic][1] [(CC0)][2]
-
-There are a number of ways to loop forever (or until you decide to stop) on Linux and you can do this on the command line or within scripts.
-
-The **for** and **while** commands make the job quite easy. There are only a few things to keep in mind with respect to syntax and tactics.
-
-**[ Also see [Invaluable tips and tricks for troubleshooting Linux][3]. ]**
-
-### Using while
-
-One of the easiest forever-loops involves using the **while** command followed by the condition "true". You don’t have to bother with logic like **while [ 1 -eq 1 ]** or similar tests. The **while true** test means the loop will run until you stop it with **CTRL-C**, close the terminal window or log out. Here's an example:
-
-```
-$ while true
-> do
->   echo Keep running
->   sleep 3
-> done
-Keep running
-Keep running
-Keep running
-^C
-```
-
-You can also do the same thing with **while :**. The key here is that the **:** always yields success so, like **while true**, this test doesn’t ever fail and the loop just keeps running.
-
-```
-$ while :
-> do
->   echo Keep running
->   sleep 3
-> done
-Keep running
-Keep running
-^C
-```
-
-If you’ve inserted an infinite loop into a script and want to remind the person who is using it how to exit the script, you can always add a hint using the **echo** command:
-
-```
-while :
-do
-        echo Keep running
-        echo "Press CTRL+C to exit"
-        sleep 1
-done
-```
-
-### Using for
-
-The **for** command also provides an easy way to loop forever. While not quite as obvious as **while true**, the syntax is reasonably straightforward. You just replace the parameters in a bounded loop that would generally look something like this "start with c equal to 1 and increment it until reaches 5" specification:
-
-```
-$ for (( c=1; c<=5; c++ ))
-```
-
-with one that doesn’t specify any parameters:
-
-```
-$ for (( ; ; ))
-```
-
-With no start value, increment or exit test, this loop will run forever or until it is forcibly stopped.
-
-```
-$ for (( ; ; ))
-> do
->    echo Keep running
->   echo “Press CTRL+C to exit”
->    sleep 2
-> done
-Keep your spirits up
-Keep your spirits up
-Keep your spirits up
-```
-
-### Why loop forever?
-
-In real life, you’re not ever going to want to loop forever, but running until it’s time to go home, the work is done or you run into a problem is not at all unusual. Any loop that is constructed as an infinite loop can also be set up to be exited depending on various circumstances.
-
-This script would keep processing data until 5 p.m. or the first time it checks the time after 5 p.m.:
-
-```
-#!/bin/bash
-
-while true
-do
-  if [ `date +%H` -ge 17 ]; then
-    exit        # exit script
-  fi
-  echo keep running
-  ~/bin/process_data     # do some work
-done
-```
-
-If you want to exit the loop instead of exiting the script, use a **break** command instead of an **exit**.
-
-```
-#!/bin/bash
-
-while true
-do
-  if [ `date +%H` -ge 17 ]; then
-    break       # exit loop
-  fi
-  echo keep running
-  ~/bin/process_data
-done
-… run other commands here …
-```
-
-#### Wrap-Up
-
-Looping forever is easy. Specifying the conditions under which you want to stop looping takes a little extra effort.
-
-Join the Network World communities on [Facebook][4] and [LinkedIn][5] to comment on topics that are top of mind.
-
---------------------------------------------------------------------------------
-
-via: https://www.networkworld.com/article/3562576/how-to-loop-forever-in-bash-on-linux.html
-
-作者：[Sandra Henry-Stocker][a]
-选题：[lujun9972][b]
-译者：[译者ID](https://github.com/译者ID)
-校对：[校对者ID](https://github.com/校对者ID)
-
-本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
-
-[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
-[b]: https://github.com/lujun9972
-[1]: https://unsplash.com/photos/u2d0BPZFXOY
-[2]: https://creativecommons.org/publicdomain/zero/1.0/
-[3]: https://www.networkworld.com/article/3242170/linux/invaluable-tips-and-tricks-for-troubleshooting-linux.html
-[4]: https://www.facebook.com/NetworkWorld/
-[5]: https://www.linkedin.com/company/network-world

translated/tech/20200616 How to loop forever in bash on Linux.md

@@ -0,0 +1,147 @@
+[#]: collector: (lujun9972)
+[#]: translator: (geekpi)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to loop forever in bash on Linux)
+[#]: via: (https://www.networkworld.com/article/3562576/how-to-loop-forever-in-bash-on-linux.html)
+[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/)
+
+如何在 Linux 的 bash 中永远循环
+======
+
+[tine ivanic][1] [(CC0)][2]
+
+在 Linux 中有很多永远循环（或直到你决定停止）的方法，你可以在命令行或脚本中执行此操作。
+
+**for** 和 **while** 命令使这件事非常容易。 关于语法和策略，只有几件事要牢记。
+
+**另请参见[用于排除 Linux 故障的宝贵技巧][3]。**
+
+### 使用 while
+
+最简单的永远循环之一是使用 **while** 命令，后面跟上条件 “true”。 你不必担心诸如 **while [ 1 -eq 1 ]** 之类的逻辑或类似的测试。 **while true** 测试表示循环将一直运行，直到你使用 **CTRL-C** 停止循环、关闭终端窗口或注销为止。 这是一个例子：
+
+```
+$ while true
+> do
+>   echo Keep running
+>   sleep 3
+> done
+Keep running
+Keep running
+Keep running
+^C
+```
+
+你也可以使用 **while :** 做同样的事情。 这里的关键是 **:** 总是返回成功，因此就像 **while true** 一样，此测试永远不会失败，并且循环会继续运行。
+
+```
+$ while :
+> do
+>   echo Keep running
+>   sleep 3
+> done
+Keep running
+Keep running
+^C
+```
+
+如果你在脚本中插入了无限循环，并想提醒使用它的人如何退出脚本，那么可以使用 **echo** 命令添加提示：
+
+```
+while :
+do
+        echo Keep running
+        echo "Press CTRL+C to exit"
+        sleep 1
+done
+```
+
+### 使用 for
+
+**for** 命令还提供了一种永远循环的简便方法。虽然不如 **while true** 明显，但语法相当简单。你只需要在有界循环中替换参数即可，界限通常类似于 “c 从等于 1 开始递增，直到 5”：
+
+```
+$ for (( c=1; c<=5; c++ ))
+```
+
+不指定任何参数的情况下：
+
+```
+$ for (( ; ; ))
+```
+
+没有起始值、增量或退出测试，此循环将永远运行或被强制停止。
+
+```
+$ for (( ; ; ))
+> do
+>    echo Keep running
+>   echo “Press CTRL+C to exit”
+>    sleep 2
+> done
+Keep your spirits up
+Keep your spirits up
+Keep your spirits up
+```
+
+### Why loop forever?
+
+在现实中，你不会想永远循环下去，但一直运行直到想要回家、工作完成或者遇到问题才退出并不罕见。任何构造为无限循环的循环都可以设置为根据各种情况退出。
+
+该脚本将一直处理数据直到下午 5 点。 或检查发现第一次超过 5 点的时间：
+
+```
+#!/bin/bash
+
+while true
+do
+  if [ `date +%H` -ge 17 ]; then
+    exit        # exit script
+  fi
+  echo keep running
+  ~/bin/process_data     # do some work
+done
+```
+
+如果要退出循环而不是退出脚本，请使用 **break** 命令而不是 **exit**。
+
+```
+#!/bin/bash
+
+while true
+do
+  if [ `date +%H` -ge 17 ]; then
+    break       # exit loop
+  fi
+  echo keep running
+  ~/bin/process_data
+done
+… run other commands here …
+```
+
+#### 总结
+
+永远循环很容易。 指定要停止循环的条件需要花费一些额外的精力。
+
+加入 [Facebook][4] 和 [LinkedIn][5] 上的 Network World 社区，评论热门主题。
+
+--------------------------------------------------------------------------------
+
+via: https://www.networkworld.com/article/3562576/how-to-loop-forever-in-bash-on-linux.html
+
+作者：[Sandra Henry-Stocker][a]
+选题：[lujun9972][b]
+译者：[geekpi](https://github.com/geekpi)
+校对：[校对者ID](https://github.com/校对者ID)
+
+本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
+
+[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/
+[b]: https://github.com/lujun9972
+[1]: https://unsplash.com/photos/u2d0BPZFXOY
+[2]: https://creativecommons.org/publicdomain/zero/1.0/
+[3]: https://www.networkworld.com/article/3242170/linux/invaluable-tips-and-tricks-for-troubleshooting-linux.html
+[4]: https://www.facebook.com/NetworkWorld/
+[5]: https://www.linkedin.com/company/network-world