#!/usr/bin/perl

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

my $twig = XML::Twig->new(
  twig_handlers => {'_all_' => \&start_tag}
);

$twig->parse(*DATA);

sub start_tag {
  my ($t, $e) = @_;
  my $str = $e->path();
  print substr(lc($str), 1), "\n";
  print lc(substr($str, 1)), "\n\n";
}

__DATA__
<A>
  <a>
   <B>blah blah</B>
   <b>blah blah blah</b>
   <b>blah <a/> blah</b>
  </a>
  <b/>
</A>