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From: kumon@asami.stars.flab.Fujitsu.co.jp (Kouichi Kumon)
Newsgroups: comp.lang.perl
Subject: Regexp bug in print context?
Message-ID: <KUMON.90Apr13130849@asami.stars.flab.Fujitsu.co.jp>
Date: 13 Apr 90 04:08:49 GMT
Sender: news@ayumi.stars.flab.fujitsu.co.jp (News)
Reply-To: kumon@flab.fujitsu.co.jp
Organization: Fujitsu Laboratories Ltd., ...
Lines: 32


 I was amazed at the behavior of regular expression searches in
print contexts.
 The following program calls subroutine &sub twice,
and the subroutine searches the same regexp from the same string.
 But the actions are different.
 The first subroutine call succeeds, but the second doesn't.
 When regexp /(0)/ in the fifth line is changed to /(1)/ or /0/ ,
it works.

 Isn't it a bug?
--------------------------
print &sub."\n";
print &sub,"\n";
sub sub {
    $c = "xx0x1x";
    if ($c =~ /(0)/) { # Why this regexp doesn't match the pattern?
	"Ok found";
    } else {
	die " not found\n";
    }
}
--------------------------

RUNNING ENVIRONMENT
Perl patchlevel 18 under sun4/110 sunos-4.0.1, use bison -y,
compiled with cc -O2.


--
Artificial inteligence lab, Fujitsu labs.
kumon@flab.fujitsu.co.jp