simple pingdom replacement

tw.sh

#!/bin/bash
# Check if your site is still up and send you a direct tweet if it isn't
#
# [dependencies]
# libwww-perl
# ruby-gem -> t
#
# [setup]
# mkdir ~/twitter_alerts
# t authorize
# crontab -e 
# */10 * * * $HOME/bin/tw.sh

WS="<your website>"
TW="<your twitter handle>"
if [ "$(HEAD $WS | head -n 1 | awk '{ print $1 }')" != "200" ]; then
  alert_sent="$HOME/.twitter_alerts/$(date +%Y%m%d_%H)"
  if [ ! -e "$alert_sent" ]; then 
    t dm $TW "$WS service is down"
    touch $alert_sent
  fi
fi