#!/usr/bin/perl

use warnings;
use strict;

use Getopt::Long;

my %pars = ( run_script => 0 );
GetOptions (
    \%pars,
    'run_script=f',
);

print "Run script $pars{run_script}\n";

allen94-lt 11: ./getopt_ex.pl -r 5
Run script 5
allen94-lt 12: ./getopt_ex.pl 
Run script 0