#!/usr/bin/perl
use warnings;
use strict;

######Your settings, change these##########################
my @hosts = ('bob.goatse@goatse.cx:password:hostname',
'user@foobar.com:password:hostname');
my $iface = 'eth0';
my $file = '~/.ip';
my $wget = '/usr/bin/wget';
###########################################################

my $ip = `/sbin/ifconfig $iface`;
$ip =~ s/\n//g;
$ip =~ s/^.*inet\s(addr:)?([\d\.]+)\s(netmask|\sBcast).+$/$2/;
my $oldip = `/bin/cat $file`;
chomp($oldip);
my $opt;
if (!@ARGV) { $opt = "-" }
else { $opt = $ARGV[0] }
if ($ip ne $oldip || $opt eq "-f") {
        foreach my $host (@hosts) {
                my @uph = split(/:/, $host);
                system("$wget -q -O /dev/null --http-user=$uph[0] ".
                "--http-passwd=$uph[1] http://www.dy.fi/nic/update?hostname=".
                "$uph[2].dy.fi");
        }
        system("/bin/echo $ip > $file");
}