#!/usr/bin/perl --

use strict;
use warnings;

use XML::Twig;

my $t = new XML::Twig(
    TwigHandlers=> {
        experiment => sub {
            use Data::Dumper;
            print join $/, @_,$_,$/;
            print $_->{att}->{accnum},$/;
            print $_->{'att'}->{'accnum'},$/;
            print $_->att('accnum'),$/;
            print $_->_dump;
            
        }
    }
);

my $xml = q~<experiment accnum="E-GEOD-8918">
<users><user id="1"/></users>
</experiment>~;

$t->parse($xml);


__END__

XML::Twig=HASH(0x19140c0)
XML::Twig::Elt=HASH(0x1ea55b8)
XML::Twig::Elt=HASH(0x1ea55b8)

E-GEOD-8918
E-GEOD-8918
E-GEOD-8918
|-experiment accnum="E-GEOD-8918"
| |-users
| | |-user id="1"