The perils of & (and prototypes too!)

ampersand.pl

#!/usr/bin/env perl

use strict;
use warnings;

$"=' and '; # this is just showing off :-)

sub mysub ($) { print "@_\n" }

sub main {
  &mysub(@_);
  mysub(@_);
  &mysub;

  my $greeting = shift;
  &mysub($greeting);
  mysub($greeting);
  &mysub;
}

main('hello world', 'good bye!');