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Re: regex: negative lookahead

by Khen1950fx (Canon)
on Dec 05, 2011 at 20:50 UTC ( #941919=note: print w/ replies, xml ) Need Help??

in reply to regex: negative lookahead

I've never had a the need to use a lookaround, but your question piqued my curiosity. As an experiment, I used Regexp::Assemble to rework your example because it just does the right thing with assertions, lookaheads, and lookbehinds.

#! /usr/bin/perl -slw use strict; use Regexp::Assemble; my $needs = Regexp::Assemble->new->add( qw[ FILE INFO ] ); my $has = Regexp::Assemble->new->add( qw[ FILE INFO SYSLOG ] ); while( defined( $_ = <DATA> )) { chomp; if( /($needs)/ ) { print $needs->as_string; } } while( defined( $_ = <DATA> )) { chomp; if( /($has)/ ) { print $has->as_string } } __DATA__ FILE INFO SYSLOG
I believe, if I"ve understood you correctly, that it works the way that it should. What do you think?

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