From: Morten Welinder <mwelinder@gmail.com>
Date: Tue, 16 May 2006 02:10:38 GMT
Subject: Re: Fix silly typo in new builtin grep
Message-ID: <118833cc0605151910s7619ddf0x8f014adba2a1eba5@mail.gmail.com>
In-Reply-To: <Pine.LNX.4.64.0605151801100.3866@g5.osdl.org>

If I read the code right, it calls regexec for every single character
on every single line.  No wonder that takes a while!  Just call it
once and it'll search for its match quite nicely.

If that's not enough, the two obvious optimizations are...

1. If the pattern contains no regexp characters  (and that is very
    common), do a strstr.

2. If the pattern must start with a specific character, search for that
    by itself.

M.