With XML::LibXML it's pretty similar. The biggest change is that libxml sticks rigidly to the XPath spec and forces you to use a namespace prefix for matching element names in the 'http://zbar.sourceforge.net/2008/barcode' namespace.

use XML::LibXML;

my $file = '00000002.TIF.xml';
my $xp = XML::LibXML::XPathContext->new(
    XML::LibXML->load_xml(location => $file),
);
$xp->registerNs(b => 'http://zbar.sourceforge.net/2008/barcode');

my $barcode_code39 = $xp->find('/b:barcodes/b:source/b:index/b:symbol[
+@type="CODE-39"]/b:data');
my $barcode_qrcode = $xp->find('/b:barcodes/b:source/b:index/b:symbol[
+@type="QR-Code"]/b:data');

$barcode_code39 = substr($barcode_code39, 0, 10);

print ("Code 39: ", $barcode_code39, "\n");
print ("QR-Code: ", $barcode_qrcode, "\n");
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