#!/usr/bin/env perl
use strict;
use warnings;

use XML::Twig;
use Data::Dumper;

sub print_book {
    my ( $twig, $book ) = @_; 
    my %this_book = map { $_ -> tag, $_ -> text } $book -> children;
    print Dumper \%this_book;
    
    $twig -> purge; 
}

my $twig = XML::Twig -> new ( 'twig_handlers' =>
                                 { 'Book' => \&print_book } );
   $twig ->  parsefile ( 'your_xml_file' );