#! /usr/bin/perl -w

use Net::SMTP::SSL;

# FETCH THE PUBLIC IP ADDRESS
$ip = `wget http://automation.whatismyip.com/n09230945.asp -O - -q ; echo`;
chomp ($ip);

# OPEN FILE THAT CONTAINS THE IP ADDRESS
# AS OF THE LAST TIME THE SCRIPT WAS RAN
open FILE, "<", "/root/scripts/currentIP" or die $!;
$currentIP = <FILE>;
chomp ($currentIP);
close FILE;

# COMPARE THE OLD IP AND THE FETCHED IP
# FOR DIFFERENCES
if ($currentIP ne $ip)
{
	#IP HAS CHANGED; EMAIL ADMIN THE NEW IP
	#AND THEN CHANGE THE IP RECORD FILE
	open FILE, ">", "/root/scripts/currentIP" or die $!;
	print FILE $ip;
	close FILE;
	&emailAdmin;
}

# E-MAIL SUB ROUTINE
# (I HAVE EXIM4 SETUP TO FORWARD TO GOOGLE 
#   SMARTHOST SO I CAN RECEIVE MAIL AS ROOT)
sub emailAdmin
{
	my $headers = "PD IP Change\nFrom: ipUpdater Script\nUser-Agent: Heirloom mailx 12.5 6/20/10\nMIME-Version: 1.0\nContent-Type: text/plain; charset=us-ascii\nContent-Transfer-Encoding: 7bit\n";
	my $to = "root";
	my $body = "The public IP address for the BPDServer has changed.\n\nNew IP: $ip\nOld IP: $currentIP\n.";
	system("echo \"$body\" | mail -s \"$headers\" \"$to\"");
}