#!/usr/bin/perl
use strict;
use warnings;
package Foo;
use Bar;

our $one;
our $two;

use vars qw($three $four);

$one = 'one';
$two = 'two';
$three = 'three';
$four = 'four';

print "$one $two $three $four\n";

Foo::switch();

print "$one $two $three $four\n";


##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
package Foo;

our $one;
our $two;

use vars qw($three $four);


sub switch {
    $one = 1;
    $two = 2;
    $three = 3;
    $four = 4;
    }
1;


##</code><code>##

[sandy][~] perl foo.pl
one two three four
1 2 3 4