docs/70507: RE in BUG section of re_format(7) in obsolete notation

[Daniel C. Sobral]

The following reply was made to PR docs/70507; it has been noted by GNATS.

From: "Daniel C. Sobral" <dcs at newsguy.com>
To: Giorgos Keramidas <keramida at FreeBSD.org>
Cc: Marian Cerny <jojo at matfyz.cz>, bug-followup at FreeBSD.org,
   "Daniel C. Sobral" <dcs at FreeBSD.org>, Ruslan Ermilov <ru at FreeBSD.org>,
   "David O'Brien" <obrien at FreeBSD.org>
Subject: Re: docs/70507: RE in BUG section of re_format(7) in obsolete notation
Date: Sat, 09 Jul 2005 23:01:07 -0300

 Giorgos Keramidas wrote:
 > On 2004-08-16 01:30, Marian Cerny <jojo at 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? :-)
 
 
 -- 
 Daniel C. Sobral			(8-DCS)
 dcs at newsguy.com
 dcs at freebsd.org
 capo at the.great.underground.bsdconpiracy.org
 
                  In related news Microsoft Windows users are now covered 
 under the Americans with Disabilities Act.