G'day nehavin,

Your first problem is your character class: those extra characters (e.g. parentheses) aren't doing what it looks like you're expecting them to do. See "perlretut: Using character classes" for details.

Beyond this, you've overcomplicated what's needed. You can use the regex as the condition and $var =~ /,/ will be true if $var contains a comma. Using !~, instead of =~, negates the result. Perhaps a review of "perlretut - Perl regular expressions tutorial" would prove useful.

You might also consider using transliteration (either y/// or tr/// — they're synonymous) which can provide a speed benefit if that's important. See "perlop: Quote-Like Operators" for details.

Here's some examples:

#!/usr/bin/env perl -l

use strict;
use warnings;

my @vars = ('abc,d', 'abcd', 'a,b,c,d');

for my $var (@vars) {
    print "var = '$var'";
    print 'm/,/: ', $var =~ /,/ ? 'not matches' : 'matches';
    print 'y/,/,/: ', $var =~ y/,/,/ ? 'not matches' : 'matches';
    print '! m/,/: ', $var !~ /,/ ? 'matches' : 'not matches';
    print '! y/,/,/: ', $var !~ y/,/,/ ? 'matches' : 'not matches';
}
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Output:

var = 'abc,d'
m/,/: not matches
y/,/,/: not matches
! m/,/: not matches
! y/,/,/: not matches
var = 'abcd'
m/,/: matches
y/,/,/: matches
! m/,/: matches
! y/,/,/: matches
var = 'a,b,c,d'
m/,/: not matches
y/,/,/: not matches
! m/,/: not matches
! y/,/,/: not matches
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