my ($dtd_file) = @_;
my $file_target = "$main::args{xml_dir}/$main::args{file}";
my $dtd_target = "$main::args{xml_dir}/$dtd_file";
my $dtd = XML::LibXML::Dtd->new("", $dtd_target);
my $parser = XML::LibXML->new();
$parser->validation(1);
my $document;

if (! -f $file_target) {
  print "Cannot find required file: $file_target\n";
  exit(0);
}

if (! -f "$dtd_target") {
  print "Cannot find required file: $dtd_target\n";
  exit(0);
}

eval {
  $document = $parser->parse_file($file_target);
  $document->validate($dtd_file);
};
if ($@) {
  print "XML not valid because of $@ !\n";
}