#!/usr/bin/perl

use strict;
use warnings;

use XML::LibXML;
use XML::LibXML::XPathContext;

my $parser = XML::LibXML->new();
my $doc    = $parser->parse_fh(\*DATA);

my $xc     = XML::LibXML::XPathContext->new( $doc->documentElement() );
$xc->registerNs( xapi => 'xmlapi_1.0' );

foreach my $ccc ($xc->findnodes('//xapi:ccc')) {
    print "Found a ccc\n";
    foreach my $d2 ( $xc->findnodes('./xapi:d2', $ccc) ) {
        print "  d2 element contained: '" . $d2->to_literal . "'\n";
    }
    if(my $animal = $xc->findvalue('./xapi:zoo/xapi:critter', $ccc) ) {
        print "  The mystery animal is '$animal'\n";
    }
}

exit;

__DATA__
<aaa xmlns="xmlapi_1.0">
  <bbb>
    <ccc>
      <d1>blah d1a</d1>
      <d2>blah d2a</d2>
      <d3>blah d3a</d3>
      <zoo>
        <critter>Monkey</critter>
      </zoo>
    </ccc>
    <ccc>
      <d1>blah d1b</d1>
      <d2>blah d2b</d2>
      <d3>blah d3b</d3>
      <zoo>
        <critter>Giraffe</critter>
      </zoo>
    </ccc>
  </bbb>
</aaa>