庆典：如何截获每个命令 [英] bash: how to intercept every command

问题描述

有没有办法拦截给庆典的每一个命令？我可以拦截特定的命令，例如， CD 定义一个函数 CD（），我可以做一个-command-在一次一对其它命令，以及。但是，我可以写一个执行每一个命令之前它被调用函数？我想要做的命令一些记账，然后执行命令。

Is there a way to intercept every command given to bash? I can intercept a particular command, e.g., cd by defining a function cd() and I can do that for one-command-at-a-time for other commands as well. But can I write a function which gets called before every command is executed? I want to do some bookkeeping of commands, and then executed the command.

米哈尔Šrajer的想法 PS4 ='$（回声$（日期）$（历史1）＆GT;＆GT; /tmp/trace.txt）TRACE：看起来很有前途的，但这里是我的输出得到：

Michał Šrajer's idea PS4='$(echo $(date) $(history 1) >> /tmp/trace.txt) TRACE: ' looks very promising but here is the output I get:

$ ping www.google.com
 TRACE: ping www.google.com
PING www.l.google.com (74.125.224.52) 56(84) bytes of data.
64 bytes from 74.125.224.52: icmp_seq=1 ttl=56 time=3.77 ms
64 bytes from 74.125.224.52: icmp_seq=2 ttl=56 time=2.33 ms
^C
--- www.l.google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 2.334/3.054/3.774/0.720 ms
  TRACE: echo -ne '\033]0;myhost.com /home/yogeshwer/github/myproject\007'
  TRACE: grep -e '\* '
  TRACE: git branch
  TRACE: sed 's/^..\(.*\)/ {\1}/'

和周三8月3日12点47分27秒PDT 2011 6672平www.google.com 被写入在/tmp/trace.txt整整5倍。四个其他的来自于我的 PS1 在我运行下面的命令的定义： $（GIT分支2 - ;的/ dev / null的| grep的-e \\ *| sed的S /^..\\(.*\\)/ {\\ 1} /）。两个问题：

And Wed Aug 3 12:47:27 PDT 2011 6672 ping www.google.com get written in /tmp/trace.txt exactly 5 times. The four other ones comes from my definition of PS1 where I run the following command: $(git branch 2> /dev/null | grep -e "\* " | sed "s/^..\(.*\)/ {\1}/"). Two questions:

• 是否有可能写入命令 /tmp/trace.txt 到底是什么？


• 而更重要的，是有可能不杂乱命令的输出，但只写命令 /tmp/trace.txt ？

• Is it possible to write the command to /tmp/trace.txt exactly?
• And more importantly, is it possible to not clutter the output of the command, but only write the command to /tmp/trace.txt?

我是如此兴奋的是能够从所有我的bash会话在一个地方记录命令的可能性！

I am so excited about the possibility of being able to record commands from all my bash sessions in one place!

推荐答案

您可以设置PS4变量，它为每一个命令，如果是跟踪上执行只是执行前评估：

You can set the PS4 variable, which is evaluated for every command being executed just before the execution if trace is on:

PS4='$(echo $(date) $(history 1) >> /tmp/trace.txt) TRACE: '

然后，启用跟踪：

Then, enable trace:

set -x

要停止跟踪，只是：

set +x

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