July 2, 2009

Check your IP periodically with a small shell script

For those who are subject to dynamically assigned DSL IP, you would probably be familiar with a site such as http://myip.dk

Here is a small script I use to fetch my public IP for other script processes

updated “due to changes on the site myip.dk, I rewrote the script”

#!/bin/bash

link=lynx -dump -listonly 'http://myip.dk' | awk -F: '/myip.dk/ && $0 != "" { getline; print $0}' | awk -F " " {'print $2'} curl -s $link | grep ‘“Box”’ | egrep -o ‘[0-9.]+’

curl -s en.myip.dk | grep ‘“Box”’ | egrep -o ‘[0-9.]+’

You may run it in a cron and email you your IP whenever it changes from the last fetch one and update your firewall rules accordingly…

Cheers,