[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#16865: grep -wP and backreferences
From: |
Stephane Chazelas |
Subject: |
bug#16865: grep -wP and backreferences |
Date: |
Tue, 25 Feb 2014 16:08:22 +0000 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
2014-02-24 20:55:42 -0800, Jim Meyering:
> On Mon, Feb 24, 2014 at 1:20 PM, Stephane Chazelas
> <address@hidden> wrote:
> > A last note: with -w, pcregrep wraps the regexp in \b...\b
> > instead of \b(?:...)\b, so it could be that those brackets are
> > not necessary in the first place.
The brackets are actually needed in cases like:
grep -Pw 'foo|bar'
(pcregrep has a bug there).
> > Maybe instead of \b(?:...)\b, we could use (?<!\w)...(?!\w)
> >
> > $ echo a%%b | grep -P '(?<!\w)%%(?!\w)'
> > $ echo %aa% | grep -P '(?<!\w)aa(?!\w)'
> > %aa%
>
> I like both suggestions. Making -wP work like grep's -w makes perfect sense.
> Care to prepare a patch to make it do that, with a separate test case?
> "git format-patch ..." output preferred, if you're game.
>
> I pushed the above patch, but would welcome another one.
Please find the patch attached.
(note that tests/word-delim-multibyte fails for me, but it's not
my doing, it was failing before).
--
Stephane
0001-Align-grep-Pw-with-grep-w.patch
Description: Text Data