#!/bin/bash

(oldip=0

while /bin/true
do ip=$(ifconfig eth0 | grep 'inet addr:' | awk -F '[:]' '{ print $2 }' | awk '{ print $1}')
if [ $oldip != $ip ] 
then url=$(head -n 1 /etc/ddnsurl)
curl -k "${url}&address=$ip"
echo updated $oldip to $ip
oldip=$ip
fi
sleep 60
done ) &