grep匹配tab

今天给maildroprc做脚本，发现不知道怎么用grep来匹配tab键，--虽然‘/t’是正则表达式的常见写法。

 

    google了一下关键字“grep匹配tab”，有两篇帖子问这个问题的，底下的回答都是设法绕开这个问题，比如用“.*”来匹配tab键，不着调，很不爽。

 

    再google一下外文吧，关键字“grep tab”，搜到一篇帖子:

 

 

 

Robert Mark Bram wrote:

> > How about just using the actual tab character?  I don't see any
> > indication that
> > grep is supposed to treat '/t' specially and it seems to behave that way
> > on linux,
> > too.
>
> I have read in many places that /t is a metacharacter for tab in regular
> expressions - but maybe that's only for sed, perl, awk etc...
> http://sitescooper.org/tao_regexps.html

Try "grep -P '/t'" to use perl-compatible regexps.  Note that this is a
specific capability of GNU grep, so it will not be portable to systems
that use a different grep.  It might be more portable to use "awk
'//t/'".

Or  to insert a literal tab as others said.

Brian

 回答得太好了：讲了三种方法： 1 grep -P '/t'; 2 awk '//t/' 3 ctl+v,tab;

 

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