ipscript

#!/bin/bash

publicip=$(dig +short myip.opendns.com @resolver1.opendns.com)

# Checks to see if there is a file which contains my current IP:
if [[ -e /tmp/currentip ]]
then
	currentip=$(cat /tmp/currentip)

	#Checks to see if my 'newly grabbed' public IP matches:
	if [[ $publicip != $currentip ]]
	then
		#First, write it to /tmp/currentip
		echo $publicip  > /tmp/currentip
		#Email me, to notify me of my new IP so I can use it.
		mutt -s "Your new IP is: " youremail@gmail.com < /tmp/currentip
	fi

# else we don't have such a file one, let's make one:
# This is for the case where your server restarts due to
# expected reasons or what not.
# More often than not, the /tmp folder may get cleared.
else
	touch /tmp/currentip
	echo $publicip > /tmp/currentip
	mutt -s "Your new IP is: " youremail@gmail.com < /tmp/currentip
fi