#!/usr/bin/env perl

use strict;
use warnings;
use Getopt::Long;
use Pod::Usage;
use Data::Dump;

my ( %options, $option );

Getopt::Long::Configure("no_ignore_case");

GetOptions( \%options, "help", "abc=s", "def=s" );

pod2usage( -exitstatus => 0, -verbose => 2 ) if $options{help}; # added

foreach $option ( $options{abc}, $options{def} ) {
    pod2usage( -exitstatus => 2, -verbose => 2 ) unless $option;
}

dd %options;

# your code here...

__END__

=pod

=head1 NAME

options.pl

=head1 SYNOPSIS

./options.pl [options]

=head1 OPTIONS

=over 8

=item B<-h, --help>

Prints a brief help message and exits.

=item B<-a, --abc>

Bla, bla.

=item B<-d, --def>

Bla, bla.

=back

=head1 DESCRIPTION

It's just an example.

=head1 USAGE

./options.pl  -a foo -d bar

=head1 BUGS

None.

=head1 AUTHOR

Karl Goethebier

=cut