20.22 Debian自带的grep不支持-P

https://scz.617.cn/unix/201109081021.txt

Q:

在Debian上执行"grep --help"可以看到:

-P, --perl-regexp   PATTERN is a Perl regular expression

但实际测试表明Debian自带的grep不支持-P:

$ echo 'foobar_infix_bar' | grep -P '(?<!foo)bar'
grep: Support for the -P option is not compiled into this --disable-perl-regexp binary

A: scz@nsfocus 2011-09-08 10:21

Debian有变通解决方案，用pcregrep即可。

aptitude install pcregrep

据说aptitude比apt-get更好。

$ echo 'foobar_infix_bar' | pcregrep '(?<!foo)bar'
foobar_infix_bar
$ echo 'prefix_foobar_suffix' | pcregrep '(?<!foo)bar'
$ echo 'foobar' | pcregrep 'foo(?!bar)'
$ echo 'foo_bar' | pcregrep 'foo(?!bar)'
foo_bar