regular expressions

asaf has asked for the wisdom of the Perl Monks concerning the following question:

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Re: regular expressions by Enlil (Parson) on Mar 19, 2003 at 04:23 UTC
one way to do it is with a look behind assertion in a regular expression. (i.e. `(?<!pattern)` like the following: `while ( <DATA> ) { print if ( m/(?<!STOR)OMA$/ ); } __DATA__ OMA COMA STORAMA HISTOROMA PUMA MELANOMA STOROMA` [download] where `m/(?<!STOR)OMA$/` pretty much looks for a pattern exactly as you described. -enlil	[reply] [d/l] [select]
Re: regular expressions by dvergin (Monsignor) on Mar 19, 2003 at 06:08 UTC
If you are just beginning to learn regexes, the negative look-behind examples given in the other posts here may feel a little challenging. Here's an approach that uses more basic regex functionality. `#!/usr/bin/perl -w use strict; my @words = qw(COMA STORAMA HISTOROMA PUMA MELANOMA STOROMA); for my $str ( @words ) { if ($str =~ /OMA$/ and $str !~ /STOROMA$/ ) { print "$str\n"; } }` [download] ------------------------------------------------------------ "Perl is a mess and that's good because the problem space is also a mess." - Larry Wall	[reply] [d/l]
Re: regular expressions by thelenm (Vicar) on Mar 19, 2003 at 04:17 UTC
Use negative lookbehind in a regular expression, like this: `/(?<!STOR)OMA\z/` [download] -- Mike `-- just,my${.02}`	[reply] [d/l]
Re: regular expressions by greenFox (Vicar) on Mar 19, 2003 at 04:10 UTC
perlman:perlre could be a good place to start. The Monastery also has a good number of beginners tutorials. -- Life is a tale told by an idiot -- full of sound and fury, signifying nothing. William Shakespeare, Macbeth	[reply]