在grep中转义感叹号？ [英] Escaping the exclamation point in grep?

问题描述

我有这个完整的行（下面的awk命令是rpm命令），我想从某些文件（包括引号）中删除。当我尝试grep和grep -F时，我似乎无法获得正确的输出。我试图从grep语句中删除部分尾行，它看起来像！造成问题。我试图用单引号包装字符串，也没有运气。谢谢。

  rpm -qVa | awk'$ 2！=c{print $ 0}'
  

解决方案

1. 使用单引号 - 当您需要单引号时，只需从单引号中删除，将其中一个加上反斜杠，然后返回：

   
   
   

   grep'rpm -qVa | awk'\''$ 2！=c{print $ 0}'\'filename




2. 使用双引号和反斜杠 - 不仅可以感叹号，还可以用shell替换其他所有内容：
   
   

   greprpm -qVa | awk '\ $ 2 \！= \c\{print \ $ 0}'filename




3. 一个POSIX字符串：

   
   
   

   grep $'rpm -qVA | awk \'$ 2！=c{print $ 0} \''filename




4. ：

   
   
   

   grep'rpm -qvA | awk。$ 2。=c{print $ 0}。'filename

   
   
   

   或者，如果您检查 $ 2 ==c以及 $ 2！=c，你可以这样做：

   
   
   

   grep'rpm -qvA | awk。$ 2 [^ =] =c{print $ 0}。'filename





我会使用POSIX字符串，也可能是简单的单引号选项 - 它具有在其他shell中工作的优势，如 dash 。




I have this full line (the rpm command into awk below) that I want to grep out from certain files, including the quotes. I can't seem to be able to get the right output when I try grep, and grep -F. I tried deleting part of the tail end of line from the grep statement and it seems like the "!" causing the problems. I tried wrapping the string in single quotes and there is no luck as well. Thank you.

rpm -qVa | awk '$2!="c" {print $0}'

解决方案

1. Use single quotes - when you need a literal single quote, just drop out of single quotes, put one in with a backslash, and then go back in:

   grep 'rpm -qVa | awk '\''$2!="c" {print $0}'\' filename

2. Use double-quotes and backslash-escape not only the exclamation point, but everything else that would otherwise get replaced by the shell:

   grep "rpm -qVa | awk '\$2\!=\"c\" {print \$0}'" filename

3. Use a POSIX string:

   grep $'rpm -qVA | awk \'$2!="c" {print $0}\'' filename

4. Use a less-specific pattern:

   grep 'rpm -qvA | awk .$2.="c" {print $0}.' filename

   or, if you have checks for $2=="c" as well as $2!="c", you could do something like this:

   grep 'rpm -qvA | awk .$2[^=]="c" {print $0}.' filename

I would go with the POSIX string, or maybe the plain single-quote option - which has the debatable advantage of working in other shells, like dash.

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