如何在单个ssh命令中使用bash $(awk)? [英] How to use bash $(awk) in single ssh-command?

问题描述

我正在尝试在ssh上执行一个包含`sub-code`或$(sub-code)的命令(我一直使用它，但我不知道它的正式名称)首先执行，但在目标服务器上执行.

I am trying to execute a single command over ssh that contains `sub-code` or $(sub-code) (I use it all the time but I don't know the official name for that) to be executed first, but on the target server.

为了论证，让我们说这是我要使用的命令.当然，可以使用hostname完成此操作，但这只是一个简化的示例，其中包含我要使用的所有格式设置向导.

For the sake of argument, let's say this is the command I want to use. Ofcourse this can be done with hostname, but this is just a simplified example that contains all the formatting wizardry I want to use.

echo `uname -a | awk '{print $2}'`

没问题.但是，如何在单个命令中正确转义以通过ssh发送它呢?以下是错误的，因为它允许服务器回复您的本地主机名.子代码在本地执行:

No problem. But how do you escape this properly to send it over ssh in a single command? The following is wrong, because it lets the server reply your local hostname. The sub-code is executed locally:

ssh myServer echo `uname -a | awk '{print $2}'`

但是想到的任何逃避现实都行不通:

But any escape-ishness that comes to mind doesn't work:

$ ssh myServer echo \`uname -a | awk '{print $2}'\`
awk: cmd. line:1: {print $2}`
awk: cmd. line:1:           ^ invalid char '`' in expression
$ ssh myServer echo \$(uname -a | awk '{print $2}')
bash: syntax error near unexpected token `('
$ ssh myServer echo \$\(uname -a | awk '{print $2}')
bash: syntax error near unexpected token `)'
$ ssh myServer echo \$\(uname -a | awk '{print $2}'\)
awk: cmd. line:1: {print $2})
awk: cmd. line:1:           ^ syntax error
bash: -c: line 0: unexpected EOF while looking for matching `)'
bash: -c: line 1: syntax error: unexpected end of file

我想要一个答案，其中包括使用正确转义的` or $() because I'd like to know if it's possible. echo`可能会更复杂.

I would like an answer that includes using properly escaped ` or $() because I'd like to know if it's possible.echo` could be something more complicated.

推荐答案

尝试一下

ssh myServer "uname -a | awk '{print \$2}' "

使用双引号"可以对将要远程执行的命令进行分组.

Use the double quotes " in order to group the commands you will execute remotely.

您还需要在$2参数中对$进行转义，以便它不是在本地计算的，而是远程传递给awk的.

You also need to escape the $ in the $2 argument, so that it is not calculated locally, but passed on to awk remotely.

如果要包含$( )，则必须再次转义$符号，如下所示:

If you want to include the $( ), you again have to escape the $ symbol, like this:

ssh myServer "echo \$(uname -a | awk '{print \$2}') "

您还可以像这样逃避反引号`:

You can also escape the backtick `, like this:

ssh myServer "echo \`uname -a | awk '{print \$2}'\` "

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