Datagram static page update check during Hurricane Sandy

check_dg.sh

#!/bin/bash
#
# Because of Hurricane Sandy (and us having all of our stuff co-located at Datagram in lower Manhattan)
# we had a major outage. I used this to monitor their website for updates.
# It's running on a local cronjob, every 5 minutes: 
#     */5 * * * * /Users/me/check_dg
# 
# More about the outage: 
#     http://www.datacenterknowledge.com/archives/2012/10/30/major-flooding-nyc-data-centers/


init_file='/tmp/dg1' #base 
new_file='/tmp/dg2'  #comparison

# create init file if running for the first time
if [ ! -f $init_file ];
then 
        touch $init_file;
fi

curl -s http://datagram.com > $new_file

if ! cmp -s "$init_file" "$new_file";
then 
        diff "$init_file" "$new_file" | mail -s "DG page update" me@mydomain.com
fi

mv $new_file $init_file;