#!/usr/bin/perl

use strict;
use warnings;
use XML::Twig;

my $twig= XML::Twig->new(
                        pretty_print => 'indented',
                        twig_roots    => { 'tm' => 1 },
                        twig_print_outside_roots => 1,
                        twig_handlers => {   tm=>sub{my $text = $_->text(); $_->cut();print $text;  },
                        },
);
$twig->parse('<?xml version="1.0"?><stats><tm tmclass="ibm" tmowner="IBM Corporation" tmtype="reg" trademark="AIX">AIX</tm></stats>');


##</code><code>##

#declare a global:
my $only_one=0;

#same as before, then:
twig_handlers => {   tm=>sub{my $text = $_->text();   $only_one ? $_->cut()  : ( $_->cut() and print $text and $only_one++ ) },

__DATA__
<?xml version="1.0"?>
                <stats>
                  <tm tmclass="ibm" tmowner="IBM Corporation" tmtype="reg" trademark="AIX">AIX</tm>
                  <tm tmclass="ibm" tmowner="IBM Corporation" tmtype="reg" trademark="AIX">AIX</tm>
                  <tm tmclass="ibm" tmowner="IBM Corporation" tmtype="reg" trademark="AIX">AIX</tm>
                </stats>'

__OUTPUT__
<?xml version="1.0"?>
                <stats>
                  AIX


                </stats>