#!/usr/bin/perl -w
# prog1.pl
print "Hello";

##</code><code>##

#!/usr/bin/perl -w
# prog1.pl
package Prog1;

sub main {
    print "Hello @_";
};

main(@ARGV) if ! caller;

##</code><code>##

# main program:
use strict;
use Prog1;

my @results = Prog1::main("steph_bow"); # equivalent to 'perl -w prog1.pm steph_bow'
...