#!/usr/bin/perl -w

use strict;

use vars qw ($foo); # "our $foo" si usamos 5.6

$foo = "global value";

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

print "mysub    result '", &mysub(),    "'\n"; # "global value"
print "localsub result '", &localsub(), "'\n"; # "local value"
print "no sub   result '", &showfoo(),  "'\n"; # "global value"

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

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

sub showfoo { 
 return $foo;
}
__OUTPUT__
$foo: global value
mysub    result 'global value'
localsub result 'local value'
no sub   result 'global value'