#!/bin/bash
#
# Watch processlist and notify differences to an admin.
#
# Usage: Just fire-off.
# If there's no basefile, it'll generate it. After that, it runs quietly.
# Only change the adminmail if needed.
#
# If you have some processes which are constantly changing, you can have them ingnored
# by changing the baselist. Just change the counter to -1 and it will be ignored the
# next run. So, "grep 2" will become "grep -1". 
# This feature might come in handy when checking i.e. a webserver. Your amount of
# httpd processes will never be constant.
#
# Bugs: Yes. Sometimes it will send you mail about "bash" or "grep".
# If it does this too often, remove the baselist, so it will re-initialize.
#
# Let it initialize by cron, as you're shell probably will not be there all the time.
#
# $Id: pcds.old,v 1.15 2002/12/22 16:35:27 bart Exp $
# $Revision: 1.15 $
#
# Bart Somers <bart@doornenburg.homelinux.net>
#
tempfile=~/outfile.txt
baselist=~/baselist.txt
currlist=~/currlist.txt
logfile=~/logfile.txt
adminmail=root@localhost
verbose=0

exec 2> /dev/null

mailcommand=`which mailx`
if [[ $? != 0 ]]; then
	mailcommand="mail"
else
	mailcommand="mailx"
fi

getprocs()
{
ps -eo comm | grep -v COMMAND | sort > $tempfile
}

makelist()
{
	if [[ -e $currlist ]]; then
		rm $currlist
	fi	
for word in `cat $tempfile`; do
	if [[ $word == $oldword ]]; then
		let "count += 1"
	elif [[ $word != $oldword ]]; then
		echo -n $oldword $count "" >> $currlist
		unset count
		oldword=$word
		let "count += 1"
	fi
done
echo >> $currlist
}

difflist()
{
	declare -a base curr
	read -a base < $baselist
	read -a curr < $currlist
	if [[ $verbose -eq "1" ]];then
		echo Base ${#base[@]} Curr ${#curr[@]}
	fi	
	count=0
	countcurr=0
	match=0
	flag=0
	while [[ $countcurr -lt ${#curr[@]} ]];do
		while [[ $count -lt ${#base[@]} ]]; do
			if [[ ${base[$count]} == ${curr[$countcurr]} ]];then
				match=1
				let intcount="$count + 1"
				let intcountcurr="$countcurr + 1"
				if [[ ${base[$intcount]} -eq "-1" ]];then
					# Proces is on ignore list
					if [[ $verbose -eq "1" ]]; then
						echo "${base[$count]} is on the ignore-list."
					fi	
				elif [[ ${curr[$intcountcurr]} -ne ${base[$intcount]} ]];then
					echo "Oops ${curr[$intcountcurr]} ${curr[$countcurr]} processes running instead of ${base[$intcount]}"
					flag=1
				elif [[ ${curr[$intcountcurr]} -eq ${base[$intcount]} && $verbose -eq "1" ]];then
					echo "Currently ${curr[$intcountcurr]} ${curr[$countcurr]} processes running. Fine."
				fi
			fi	
			#echo "countcurr= $countcurr"
			#sleep 1
			let count="$count + 2"
		done
		#echo "count= $count"
		#sleep 1
	if [[ $match -eq "0" ]];then
		echo "${curr[$intcountcurr]} ${curr[$countcurr]} processes running. Not seen before."
		flag=1
	fi	
	let countcurr="$countcurr + 2"
	count=0
	match=0
	done
}

getprocs

if [[ $1 == "-init" || ! -e $baselist ]]; then
	makelist
	cp $currlist $baselist
	echo "Initialization complete." >> $logfile
	cat $logfile | $mailcommand -s "PCDS logging from `hostname` " $adminmail
	exit 0
fi

makelist
difflist >> $logfile

if [[ $verbose -eq "1" ]];then
	ls -l $logfile
#	cat $logfile
fi

if [[ -e $logfile && $flag -eq "1" ]]; then
	cat $logfile | $mailcommand -s "PCDS logging from `hostname` " $adminmail
fi

#Do some clean-up work

if [[ -e $tempfile ]]; then
	rm $tempfile
fi
if [[ -e $currlist ]]; then
	rm $currlist
fi

if [[ -e $logfile ]]; then
	rm $logfile
fi

exit 0