#!/usr/bin/perl -w
use strict;
use XML::Twig;
my $xml_string = <<EOF;
<?xml version="1.0"?>
<root> 
  <aaa id='test'> 
    <bbb/> 
  </aaa> 
</root> 
EOF

my $t= XML::Twig->nparse( $xml_string);
my $elem= $t->getElementById( 'test');
$elem->print;