/usr/bin/perl

use strict;
use warnings;

use XML::Twig;


my $twig = XML::Twig->parse( map_xmlns => { 'http://www.w3.org/2001/XMLSchema' => 'xsd', }, \*DATA);

printf "\$twig->root->gi: %s\n", $twig->root->gi;
printf "\$twig->root->namespace: %s\n", $twig->root->namespace;

__DATA__
<schema xmlns="http://www.w3.org/2001/XMLSchema"><element name="alert"/></schema>

##</code><code>##

$twig->root->gi: xsd:schema
$twig->root->namespace: http://www.w3.org/2001/XMLSchema