#!/usr/bin/perl

use warnings;
use strict;
use Carp;

my $input = shift or croak "Give me an argument, fool!\n";
my %action = (
              foo => sub { print "fooing\n" },
              bar => sub { print "barred\n" },
              baz => sub { print "all bazzed out\n" },
              );

if (my ($match) = $input =~ m/(foo|bar|baz)/ ){
    &{$action{$match}};
} else {
    croak "Dunno what to do\n";
}