Quickies, by Andrea Olivato

Update DynDns host with current IP with Perl

Updates any DynDns host with current IP address. Useful if put in crontab and executed every 15mins.

#!/usr/bin/perl

# Load Needed Modules
use strict;
use XML::Simple;
use LWP::UserAgent;

# Get login data
my $username="DynDns_user";
my $password="DynDns_user";
my $hostname="yourhost.example.com";

# Create a new useragent
my $ua = new LWP::UserAgent;
$ua->agent('Mozilla/5.0 (X11; ; Linux i686; it; rv:1.9.1) Gecko/20090701');

# Create and perform a request to get current IP address
my $req = new HTTP::Request GET => "http://ip-address.domaintools.com/myip.xml";
my $content = $ua->request($req)->content();

# Create XML class and parse results
my $xml = new XML::Simple (KeyAttr=>[]);
my $data = $xml->XMLin($content);

# Get my current ip address from xml tree
my $ip = $data->{ip_address};
my $old;

# Open script log and read old ip address
open (MYFILE, '/tmp/ip-ch.log');
$old = ;
close (MYFILE);

# Open script log and write new ip address
open (MYFILE, '>/tmp/ip-ch.log');
print MYFILE $ip;
close (MYFILE);

# If new ip is different from previous one
if ($old != $ip) {

        # Create a new useragent
        my $ua = new LWP::UserAgent;
        $ua->agent('Mozilla/5.0 (X11; ; Linux i686; it; rv:1.9.1) Gecko/20090701');

        # Create and perform a request to update hostname associated ip
        my $req = new HTTP::Request GET => 'http://'.$username.':'.$password.'@members.dyndns.org/nic/update?hostname='.$hostname.'&myip='.$ip.'&wildcard=NOCHG&mx=NOCHG&backmx=NOCHG';
        $ua->request($req)->content();
}