From owner-freebsd-hackers@FreeBSD.ORG  Wed Jun 18 05:43:40 2008
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Date: Wed, 18 Jun 2008 08:23:47 +0300
From: Jaakko Heinonen <jh@saunalahti.fi>
To: Gabor Kovesdan <gabor@FreeBSD.org>
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Cc: Doug Barton <dougb@FreeBSD.org>, current@FreeBSD.org,
	Diomidis Spinellis <dds@aueb.gr>, hackers@FreeBSD.org,
	"Sean C. Farley" <scf@FreeBSD.org>, Max Khon <fjoe@samodelkin.net>
Subject: Re: CFT: BSD-licensed grep [Fwd: cvs commit:
	ports/textproc/bsdgrep Makefile distinfo]
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On 2008-06-17, Gabor Kovesdan wrote:
> > egrep: empty (sub)expression
> >
> I've looked at this and I have a patch with a workaround: 
> http://kovesdan.org/patches/grep.dougb.diff

Unfortunately this breaks things. For example:

$ grep -E '(test||test)' /dev/null
grep: parentheses not balanced
$ grep -E '(test|\|)' /dev/null
grep: parentheses not balanced
$ grep -E '\(|test)' /dev/null
(should give an error but it hangs)

-- 
Jaakko