[debbugs-tracker] bug#23185: closed (GNU grep matching discrepancy between -a/--text and not.)

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Your message dated Tue, 5 Apr 2016 23:56:22 -0700
with message-id <address@hidden>
and subject line Re: bug#23185: GNU grep matching discrepancy between -a/--text 
and not.
has caused the debbugs.gnu.org bug report #23185,
regarding GNU grep matching discrepancy between -a/--text and not.
to be marked as done.

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23185: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=23185
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> --- Begin Message ---
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> Subject: 
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> GNU grep matching discrepancy between -a/--text and not.
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> Date: 
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> Sat, 2 Apr 2016 15:00:12 +0300
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> Hi all,
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> as can be seen in this repository:
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> https://github.com/shlomif/gnu-grep-trailing-space-and-CR-on-riddles.he-false-match
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> GNU grep says a document it suspects to be binary matches without -a/--text and
> doesn't match it or return results with that flag applied. perl sides with the
> latter.
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> I'm on Mageia linux x86-64 v6 and have built GNU grep from the latest git
> commit ( c767ed70eca9a82d76f07dcdbcaafa21ec7f86d6 ) to test.
>
> Regards,
>
>         Shlomi Fish
>
> P.S: it seems the build system uses gperf but configure does not verify that it
> exists in the path.
>
> -- 
> -----------------------------------------------------------------
> Shlomi Fish       http://www.shlomifish.org/
> Interview with Ben Collins-Sussman - http://shlom.in/sussman
>
> Can I SCO now? Sue who you wanna sue, it doesn't matter anyhoo, it's time to
> litigate.
>     — http://www.shlomifish.org/humour/bits/Can-I-SCO-Now/
>
> Please reply to list if it's a mailing list post - http://shlom.in/reply .
>
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> --- End Message ---

--- Begin Message --- Subject: Re: bug#23185: GNU grep matching discrepancy between -a/--text and not. Date: Tue, 5 Apr 2016 23:56:22 -0700 User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 Thanks for pointing out the seeming inconsistency. The documentation mentions the issue but is perhaps not clear enough, so I installed the attached patch.

The input file contains NUL bytes and so is treated as binary data, and the grep documentation (secton "File and Directory Selection", option "--binary-files") says "When processing binary data, ‘grep’ may treat non-text bytes as line terminators". This behavior was added to GNU grep in release 2.21 dated 2014, partly for performance reasons.

There are two instances in riddle.he of a space followed by a NUL byte, so

  grep -P '[ \t]\r?$' riddles.he

finds a match when the $ matches just before the NUL byte.

-a is one way to get the behavior you evidently expected. Another (perhaps better) way is -z. The command:

  grep -zP '[ \t]\r?\n' riddles.he

outputs nothing and exits with status 1.

0001-Give-another-example-of-binary-file-processing.patch
Description: Text Data

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