GNU bug report logs - #26193
[0-9] versus [[:digit:]]

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Package: grep;

Reported by: "John P. Linderman" <jpl.jpl <at> gmail.com>

Date: Mon, 20 Mar 2017 17:00:02 UTC

Severity: normal

Done: Jim Meyering <jim <at> meyering.net>

Bug is archived. No further changes may be made.

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From: Paul Eggert <eggert <at> cs.ucla.edu>
To: "John P. Linderman" <jpl.jpl <at> gmail.com>, Jim Meyering <jim <at> meyering.net>
Cc: 26193 <at> debbugs.gnu.org, Gnulib bugs <bug-gnulib <at> gnu.org>
Subject: bug#26193: [0-9] versus [[:digit:]]
Date: Wed, 22 Mar 2017 11:01:43 -0700
On 03/22/2017 05:44 AM, John P. Linderman wrote:
> That puts the runtimes on equal footing:
>
In my measurements, P[0-9] is still a tiny bit slower if one is using 
glibc regex, due to a performance problem in glibc. You can work around 
it by configuring --with-included-regex. It's probably not worth 
worrying about, though.

By the way, using LC_ALL=C should help avoid performance problems like 
these in the future, if all you're doing is something where single-byte 
pattern matching suffices.





This bug report was last modified 8 years and 66 days ago.

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