#!/bin/bash
#####################################################################
# checkpage.sh   v 0.2.3   (!c) by Michael Horn <nibbler@nibbler.de>
#####################################################################
# global settings
#####################################################################

# where to store the copy of the page we want to compare with?
storefile=/tmp/_pagecheck-storefile

# what url to check
url=http://www12.informatik.uni-erlangen.de/edu/

# where to send email notifies
mailaddr=changeme@nibbler.de

# time in minutes to wait between periodic checks
checkmins=1

#####################################################################

ua="checkpage.sh by nibbler@nibbler.de"

case $1 in
        "--help")
                echo usage: checkpage [fetch\|compare\|pcheck]
		echo
		echo \ \ \ \ \ \ \ fetch - fetch the page and store it in the storefile for later comparison
		echo \ \ \ \ \ \ \ compare - compare the file on the server with the storefile and give diff output
                echo \ \ \ \ \ \ \ pcheck - check periodically. if changed, notify by email
		echo
		echo due to the nature of the script you have to specify a fixed URL and a fixed
		echo storefile in a variable as well as email address for notifies within the script.
		echo
                exit 0
        ;;
        "")
                echo for usage information see --help
                exit 0
        ;;
        "fetch")
                wget -U $ua -q -O - $url|sed -r s/.PHPSESSID=\(.{32}\)//|sed -r s/.PHPSESSID=\(.{32}\)//>$storefile
                exit 0
	;;
	"compare")
		wget -U $ua -q -O - $url|sed -r s/.PHPSESSID=\(.{32}\)//|sed -r s/.PHPSESSID=\(.{32}\)//|diff $storefile -
		exit 0
	;;
	"pcheck")
		while true
			do
				case `wget -U $ua -q -O - $url|sed -r s/.PHPSESSID=\(.{32}\)//|sed -r s/.PHPSESSID=\(.{32}\)//|diff $storefile -` in
					"")
						sleep `echo 60*$checkmins|bc`
					;;
					*)
						wget -U $ua -q -O - $url|sed -r s/.PHPSESSID=\(.{32}\)//|sed -r s/.PHPSESSID=\(.{32}\)//|diff $storefile -|sendmail $mailaddr
						sleep `echo 60*$checkmins|bc`
					;;
				esac
			done
        ;;
	*)
		echo invalid syntax - please use --help
		exit 1
	;;
esac