#!/usr/bin/perl
use strict;
use warnings;

use Getopt::Long;

my %options = ();

GetOptions (
             "a=s" => \$options{'a'},
             "b=s" => \$options{'b'},
             "z!"  => \$options{'z'},
            );

my %Subs = (
             'a' => \&do_a,
             'b' => \&do_b,
             'z' => \&do_z,
            );

while (my ($sub_name, $function) = each %Subs){
    $function->($options{$sub_name});
}

sub do_a {
  my $active = shift;
  return unless $active;
  
  my $param1 = $active;
#  my $param2 = shift @ARGV;
#  print "$param1, $param2, \n";
}

sub do_b {
  my $active = shift;
  return unless $active;
  
  my $param1 = $active;
#  my $param2 = shift @ARGV;
#  print "$param1, $param2, \n";

}

sub do_z {
  my $active = shift;
  return unless $active;
  
  #do stuff without parameters
}