use Getopt::Long;

sub get_options {
        my $def = shift;
        my $cur = {};
        $cur->{$_->[0]} = $_->[2] for @$def;
        my @def = map {$_->[0].$_->[1]} @$def;
        GetOptions( $cur, @def );
        return $cur;
}

my $defaults = [
	[ debug => '' => 0 ],
    [ help => '' => 0 ],
    [ interactive => '' => 0 ],
    [ host => '=s' => '999.999.999' ],
    [ username => '=s' => 'username' ],
    [ home => '=s' => $ENV{HOME} ],
    # ...
];

my $opt = get_options( $defaults );

# if ( $opt->{help} ) { ... }
# foo( $opt->{host} );