#! perl -sw
use strict;

my %cat = (
  'C[AEIOU]NWAY' => 'AAA',
  '(BOSTON|CHICAGO)' => 'BBB',
  '(LAS VEGAS|NEVADA)' => 'CCC',
  '(DALLAS|AUSTIN)' => 'DDD',
  '(NASHVILLE|M[AEIOU]MPHIS)' => 'EEE',
);

my $variable = 'CHICAGO';

for (keys %cat) {
	print $cat{$_}, $/ if $variable =~ /$_/;
}

__END__
#Output
c:\test>211023
BBB

c:\test>