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From: ado@elsie.UUCP (Arthur David Olson)
Newsgroups: comp.bugs.4bsd,comp.bugs.sys5
Subject: Re: egrep botch
Message-ID: <7518@elsie.UUCP>
Date: Fri, 23-Oct-87 16:47:23 EST
Article-I.D.: elsie.7518
Posted: Fri Oct 23 16:47:23 1987
Date-Received: Sun, 25-Oct-87 18:17:09 EST
References: <8759@utzoo.UUCP>
Organization: NIH-LEC, Bethesda, MD
Lines: 40
Summary: Ambition should be made of Sterno stuff
Xref: mnetor comp.bugs.4bsd:603 comp.bugs.sys5:265

> The following bug appears to be present in egrep (the Bell/AT&T one, not
> the comp.sources.unix one) on all extant versions of Unix.  Certainly it
> is present in V7, 4.2BSD, Sunnix 3.2, and 386 System V Release 3.
> 
> 	% echo 0 >foo
> 	% egrep '0.' foo
> 	% egrep '^0.' foo
> 	0
> 	%
> 
> Adding the "^" seems to convince egrep that "." can legitimately match
> newline.  Changing "." to "[^x]" does not change the behavior.  Some quick
> tests suggest that "$" does not produce a similar anomaly.

The change below cures the problem, and even "looks right."
Your line numbers will vary.

*** 3.2/egrep.y	Fri Oct 23 16:34:20 1987
--- 3.3/egrep.y	Fri Oct 23 16:34:24 1987
***************
*** 303,309 ****
  					if ((k = name[curpos]) >= 0)
  						if (
  							(k == c)
! 							| (k == DOT)
  							| (k == CCL && member(c, right[curpos], 1))
  							| (k == NCCL && member(c, right[curpos], 0))
  						) {
--- 303,309 ----
  					if ((k = name[curpos]) >= 0)
  						if (
  							(k == c)
! 							| (k == DOT && c != '\n')
  							| (k == CCL && member(c, right[curpos], 1))
  							| (k == NCCL && member(c, right[curpos], 0))
  						) {
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