Simple web page monitor with email notification

page-monitor.sh

#!/bin/sh
#
# Monitor a web page and notify changes
#
# requires wget, diff and sendmail
# for sendmail I use ssmtp
#

TITLE="Example Offers"
WWW="http://www.example.com/offers.html"
DIR="/home/username/monitor_example"
EMAIL_TO="[email protected]"
EMAIL_FROM="[email protected]"

cd "$DIR"
if [ -e "this.html" ]; then
    mv this.html last.html
fi

wget -O this.html "$WWW"
diff -q this.html last.html
if [ $? -ne 0 ]; then

MAIL="To: $EMAIL_TO
From: $EMAIL_FROM
Subject: $TITLE page changed

The $TITLE page appears to have changed.

Please visit:

$WWW

----- 

"
    echo "$MAIL" > mail.txt
    diff last.html this.html >> mail.txt

    /usr/sbin/sendmail "$EMAIL_TO" < mail.txt
fi