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Date:	Thu, 5 Nov 2009 22:32:43 -0500
From:	Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: 1.7] BUG - GREP slows to a crawl with large number of matches on a single file
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On Thu, Nov 05, 2009 at 07:11:02PM -0800, Linda Walsh wrote:
>aputerguy wrote:
>> Running grep on a 20MB file with ~100,000 matches takes an incredible almost
>> 8 minutes under Cygwin 1.7 while taking just 0.2 seconds under Cygwin 1.5
>> (on a 2nd machine).
>
>I've seen nasty behavior with grep that isnt' cygwin specific.  Try
>"pcregrep" and see if you have the same issue.
>
>I found it to be about ~100 times faster under _some_ searches though
>2-3x is more typical.  The gnu re-parser isn't real efficient under
>some circumstances.
>
>If you find a big difference, you might also want to report it to the
>bug-grep AT gnu DOT org mailing list, but last time I did, they told me
>"that's the way it is" due to some posix conformance thing...

The fact that it behaves differently between Cygwin 1.5 and 1.7 would
suggest that this isn't a grep problem.

That's why I asked for a test case.

cgf

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