use strict;
use warnings;
use XML::LibXML;

  my $filename = $ARGV[0];

  my $parser = XML::LibXML->new();
  my $doc    = $parser->parse_file($filename);
  my $xc = XML::LibXML::XPathContext->new( $doc->documentElement()  );


  foreach my $sections ($xc->findnodes('/HOSTNAME/PATROL/ACL/USERNAME')) {
    my($username) = $sections->getAttribute('name');
    my($permissions) = $sections->findnodes('./PERMISSION');
    my($host) = $sections->findnodes('./HOST');
    print $username->to_literal, "\n";
    print $permissions->to_literal, "\n";
    print $host->to_literal, "\n";
  }