#! perl -w
use strict;
use warnings;

use mystuff;

mystuff::say_hello "world";

##</code><code>##

#! perl -w
use warnings;
use strict;

package mystuff;

sub say_hello {
    print "hello " . shift() . "\n";
}

1

##</code><code>##

$ perl -w example.pl

##</code><code>##

hello world