GNU bug report logs - #62483
echo a | grep -E -w '((()|a)|())*' # does not terminate

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Message #41 received at 62483 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: arnold <at> skeeve.com, dimitry <at> andric.com
Cc: 62483 <at> debbugs.gnu.org, koen <at> chalmers.se
Subject: Re: bug#62483: echo a | grep -E -w '((()|a)|())*' # does not terminate
Date: Sun, 2 Apr 2023 11:29:39 -0700

On 2023-04-01 23:52, arnold <at> skeeve.com wrote:
> It's interesting, as gawk uses the same regex, but with different flags.

Also, GNU grep -w passes the following more-complicated regexp to dfaparse:

  (^|[^[:alnum:]_])(((()|a)|())*)([^[:alnum:]_]|$)

and quite possibly the bug is related to this extra complexity.

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