& XSLT I trying to put together a script that searches an XML file for a  
specific entry, and then returns children of that node. I have it  
working with XML::XPath, but it seems slower than I would like.

I am confused with the namespace issues using XML::LibXML::XPathContext.

The files that I am searching/parsing are the NIST's NVD CVE files.  
The header lists multiple namespaces (to my novice eye, anyway...):

<?xml version='1.0' encoding='UTF-8'?> 
<nvd xmlns="http://scap.nist.gov/schema/feed/vulnerability/2.0"  
xmlns:cvss="http://scap.nist.gov/schema/cvss-v2/0.2"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:vuln="http://scap.nist.gov/schema/vulnerability/0.4" xmlns:cpe- 
lang="http://cpe.mitre.org/language/2.0"
nvd_xml_version="2.0" pub_date="2009-01-28T03:30:00"  
xsi:schemaLocation="http://scap.nist.gov/schema/feed/vulnerability/2.0 http://nvd.nist.gov/s
chema/nvd-cve-feed_2.0.xsd 
"> 

The entries look like this:
       <entry id="CVE-2006-0069"> 
         <vuln:vulnerable-configuration id="http://nvd.nist.gov"> 
             <cpe-lang:logical-test negate="false" operator="OR"> 
                 <cpe-lang:fact-ref name="cpe:/ 
a:chipmunk_scripts:chipmunk_guestbook:1.4" /> 
             </cpe-lang:logical-test> 
         </vuln:vulnerable-configuration> 
         <vuln:vulnerable-software-list> 
             <vuln:product> cpe:/a:chipmunk_scripts:chipmunk_guestbook: 
1.4</vuln:product> 
         </vuln:vulnerable-software-list> 
         <vuln:cve-id> CVE-2006-0069</vuln:cve-id>
         <vuln:published-datetime> 2006-01-03T18:03:00.000-05:00</ 
vuln:published-datetime> 
         <vuln:last-modified-datetime> 2008-09-05T16:58:16.357-04:00</ 
vuln:last-modified-datetime> 
         <vuln:cvss> 
             <cvss:base_metrics upgraded-from-version="1.0"> 
                 <cvss:score> 4.3</cvss:score>
                 <cvss:access-vector approximated="true"> NETWORK</ 
cvss:access-vector> 
                 <cvss:access-complexity> MEDIUM</cvss:access-complexity>
                 <cvss:authentication> NONE</cvss:authentication>
                 <cvss:confidentiality-impact> NONE</ 
cvss:confidentiality-impact> 
                 <cvss:integrity-impact> PARTIAL</cvss:integrity-impact>
                 <cvss:availability-impact> NONE</cvss:availability- 
impact> 
                 <cvss:source> http://nvd.nist.gov</cvss:source>
                 <cvss:generated-on- 
datetime> 2006-01-04T08:48:00.000-05:00</cvss:generated-on-datetime>
             </cvss:base_metrics> 
         </vuln:cvss> 

this carries on, but what I'm interested in is in this chunk.

The code looks like this:

#!/usr/bin/perl -w

use strict;
use warnings;

# use XML::XPath;
# use XML::XPath::XMLParser;
use XML::LibXML;
use XML::LibXML::XPathContext;

die "Usage:  $0 CVE Identifier\n"   unless  1 == @ARGV;

# my $cve_id = 'CVE-2008-3763';
my $cve_id = $ARGV[0];

# parse the CVE identifier to determine what data file to search
my @id_fields = split(/-/,$cve_id);
my $year = $id_fields[1];

my $data_file = "./nvdcve-2.0-" . $year . ".xml";

my $xp = XML::LibXML::XPathContext->  new($data_file);

for my $entry ($xp-> findnodes("/nvd/entry[\@id = '$cve_id']")) {
    my ($metrics) = $entry-> findnodes('vuln:cvss/cvss:base_metrics');

    my $av = $metrics-> find('cvss:access-vector');
    my $ac = $metrics-> find('cvss:access-complexity');
    my $au = $metrics-> find('cvss:authentication');
    my $ci = $metrics-> find('cvss:confidentiality-impact');
    my $ii = $metrics-> find('cvss:integrity-impact');
    my $ai = $metrics-> find('cvss:availability-impact');

print $av . "\n";
print $ac . "\n";
print $au . "\n";
print $ci . "\n";
print $ii . "\n";
print $ai . "\n";
    last;
}

What do I register as a namespace to make things work?

As always, thanks for any help!

Scott...