#!/usr/bin/perl -w

use strict;

use vars qw ($foo); # or "our $foo" if you're using 5.6

$foo = "global value";

print "\$foo: $foo\n"; # prints "global value"

sub mysub {
	my $foo = "my value";
	showfoo(); # prints "global value"
}

sub localsub {
	local $foo = "local value";
	showfoo(); # prints "local value
}

sub showfoo {
	print "\$foo: $foo\n";
}