Date: Sun, 10 Jul 2005 12:10:30 GMT From: Giorgos Keramidas <keramida@freebsd.org> To: freebsd-doc@FreeBSD.org Subject: Re: docs/70507: RE in BUG section of re_format(7) in obsolete notation Message-ID: <200507101210.j6ACAUL6008536@freefall.freebsd.org>
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The following reply was made to PR docs/70507; it has been noted by GNATS.
From: Giorgos Keramidas <keramida@freebsd.org>
To: "Daniel C. Sobral" <dcs@newsguy.com>
Cc: Marian Cerny <jojo@matfyz.cz>, bug-followup@freebsd.org,
"Daniel C. Sobral" <dcs@freebsd.org>, Ruslan Ermilov <ru@freebsd.org>,
"David O'Brien" <obrien@freebsd.org>
Subject: Re: docs/70507: RE in BUG section of re_format(7) in obsolete notation
Date: Sun, 10 Jul 2005 15:05:55 +0300
On 2005-07-09 23:01, "Daniel C. Sobral" <dcs@newsguy.com> wrote:
>Giorgos Keramidas wrote:
>>On 2004-08-16 01:30, Marian Cerny <jojo@matfyz.cz> wrote:
>>> Shouldn't this paragraph in BUGS section in manual page of re_format:
>>>
>>> Back references are a dreadful botch, posing major problems for
>>> efficient implementations. They are also somewhat vaguely
>>> defined (does `a\(\(b\)*\2\)*d' match `abbbd'?).
>>> Avoid using them.
>>>
>>> be
>>>
>>> Back references are a dreadful botch, posing major problems for
>>> efficient implementations. They are also somewhat vaguely
>>> defined (does `a((b)*\2)*d' match `abbbd'?).
>>> Avoid using them.
>>>
>>> because `a\(\(b\)*\2\)*d' is in obsolete notation? Or does this bug
>>> concern only the obsolete REs?
>>
>> You're probably right that we should change the syntax to look like a
>> modern RE. The basic RE syntax is still used by many utils in the base
>> system though. This is probably why the regexp has remained as you see
>> it now.
>>
>> Daniel, Ruslan and David... what do you think? Is this change ok?
>
> Old, OLD messages... This was lost in a number of spams I'm happing to
> be clearing right now. Thing about back references is... they didn't
> work with Extended Regex, only with basic Regex, which is the obsolete
> notation.
>
> So I'm guessing the rewritten example wouldn't work, because back
> references is not supported with that syntax. So, if this change was
> done, could someone check if back references are actually supported in
> extended regex (the modern syntax), and, if not, undone this change? :-)
Nothing was changed, since I wasn't sure of what to do.
Thanks for the clarification :-)
Does this mean we can close this PR now?
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