Retrieves the IP of the supplied hostname hourly and pops up a Growl Notification if/when the IP changes. I use it when switching a website to a new server. Note: This does require Growl and the GrowlNotify plug-in. I may rewrite it in the future support the Notification Centre in Mountain Lion and provide more options.

domain-check.sh

#!/bin/bash

echo "Enter the hostname you want to monitor (eg citypress.co.uk) and hit [ENTER]: "

read hostname

while true; do
	newip=$(dig +short $hostname)
	if [ "$newip" != "$previp" ]; then
		if [ -z "$previp" ]; then
			growlnotify --title "NOW MONITORING:" --message "$hostname - current IP $newip"
		else
			growlnotify --sticky --title "IP HAS CHANGED" --message "$hostname is now at $newip"
		fi
	else
		echo "No change"
	fi
	previp=$newip
	sleep 600
done