email when unix system CPU usage is above 70%
 

Hey Colleagues;
I need to write a shell script that will send me an email when unix system CPU usage is bove 70% threshold, will really appreciate your response as i equally put it together from my end.

70% of one processor usage? 70% of all procs? Do you include hyper-threading virtual procs in this count? 70% instantaneous or time-averaged? Over what length of time? When the limit is exceeded, how do you want to handle emails. Every minute while it's over the limit? Every 5 minutes? Once when it passes the limit and not again until it drops back below for at least XX minutes, then rises back above?

When 70% of all processes, an email should be sent to a specified email id with a subject "WARNING CPU USAGE HIGH"

That answered one of the five questions that were asked.

You can't expect to tackle a problem (or have somebody else tackle the problem for you) if you can't define it properly.

Show us what you've got already then.

Let me be more explicit
 

I intend to explain in details what i really want so i can get suport easily from you guys, i want a script that can monitor CPU usage of unix system so that if the CPU usage is more than 70% your script will send out email saying that CPU is more than threshold of 70%. I created the below script but it did send a warning email but the percentage was wrong when compared to the result when i use the "top" command.
#!/bin/sh
#Date = 10/18/2013
#Set the alarm threshold here
#Set to 70 to make it send notifications if average utilization goes past 70%
THRESHOLD=70

MAILTO="meray@company.com"
#The temp file below will be replaced everytime this script runs
TEMPFILE=/tmp/cpu.temp

#
#LOGIC BLOCK:
#

HOSTNAME=`isbinf03`
rm -f $TEMPFILE

#Calculate the CPU Utilization with the command below
#Note: this command will calculate the avg CPU utilization of last 10 secs
CPU=$(vmstat 10 2 | tail -1 | awk '{print $15}' | sed 's/%//')
let "CPU = 100 - $CPU"
#echo "`date` - CPU Utilization: $CPU"

#Compare the current value with the threshold one.
if [ $(expr $CPU ">=" $THRESHOLD) -ne 0 ]
then
echo "Warning - CPU utilization on server $HOSTNAME is ${CPU}%" >> $TEMPFILE
fi

#Send an email if /tmp/cpu.temp is present.
if [ -e $TEMPFILE ]
then
mail -s "$HOSTNAME CPU Warning" $MAILTO < $TEMPFILE
fi

rm -f $TEMPFILE
once again i will appreciate your help.

It would help if you read http://en.wikipedia.org/wiki/Load_%28computing%29 as it shows you how to calculate CPU usage like you should?