package Menu;

use strict;
use Exporter;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK);

$VERSION     = 1.00;
@ISA         = qw(Exporter);
@EXPORT      = ();
@EXPORT_OK   = qw( show_menu );

sub show_menu {
    my ( $authenticated ) = @_;
    if ( $authenticated ) {
        # blah
    }
    else {
        # blah
    }
}

1;


# script

#!/usr/bin/perl
use lib '/see/tutorial/for/details';
use Menu qw( show_menu );
my $authen = check_authen();
show_menu( $authen );