my @list = ();
my $parser = XML::LibXML->new();

sub Process($)
{
  my $f = shift;
  if (-f $f and -r $f)
  {
    if (scalar(grep($_ eq $f, @list)) == 0)
    {
      push @list, $f;
      my $root = $parser->parse_file($f)->documentElement();
      my $prefix = $root->lookupNamespacePrefix('http://www.w3.org/2001/XInclude');
      if ($prefix)
      {
        my $ok = 1;
	foreach my $xincludeNode ($root->getElementsByTagName("$prefix:include"))
	{
	  my $xincludeFilename = File::Spec->rel2abs($xincludeNode->getAttribute('href'));
	  $ok &&= Process($xincludeFilename);
	}
        return $ok;
      }
      else
      {
        return 1;
      }
    }
    else
    {
      return 1;
    }
  }
  else
  {
    print STDERR "The file '$f' isn't found or not readable\n";
    return 0;
  }
}
  
Process(File::Spec->rel2abs($ARGV[0]));
my $list = join("\n", @list);
print $list, "\n";