This is a script that will check the current CPU usage of a program/process and kill it if it uses too much. This is useful if you are for some reason forced to run buggy, closed source software which get stuck in endless loops when things go wrong.

#!/bin/bash

# By: Noel
#
# bash code to watch a running program's CPU usage.
# if it's above a set value, it will auto send an email.
# You will need to set a Cron job to run this script every xx minutes
#
# Set some needed things:
#
processToWatch="convert" # in my case I need to watch convert
emailAddress="root@host" # this is my main emailaddress
triggerValue=90 # if the CPU use is above 90% send an email. DO NOT USE a DOT or COMMA!
tempFileName=tmp-cpu # some name of the temp file for the ps, grep data

ps auxww | grep "$processToWatch" | grep -v grep > /tmp/$tempFileName
export LINE
(
read LINE
while [ -n "$LINE" ]
do
set $LINE
read LINE
if [ $(echo "$3" | sed -e 's/.[0-9]*//g') -gt $triggerValue ]; then
mail -s "CPU message alert for: $processToWatch" $emailAddress <<-END
This is to inform you that the following process: $processToWatch with PID (Process ID) $2 is now using more than your preset $triggerValue value.

Process: $processToWatch is using: $3 of CPU power!
The command used is: $11
END
fi
done
)< /tmp/$tempFileName