Hi,
My aim is to write a script to kill users who are idle more than 30 minutes. I wrote follwoing script, getting help from one of the scripts available in these forums:

#!/bin/sh

who -u | awk '{print $1,$6,$7}' > user.txt


grep ":3" /tayyab/user.txt > /tayyab/idle_u.txt
grep ":4" /tayyab/user.txt >> /tayyab/idle_u.txt
grep ":5" /tayyab/user.txt >> /tayyab/idle_u.txt
grep ":6" /tayyab/user.txt >> /tayyab/idle_u.txt
grep "1:" /tayyab/user.txt >> /tayyab/idle_u.txt
grep "2:" /tayyab/user.txt >> /tayyab/idle_u.txt
grep "3:" /tayyab/user.txt >> /tayyab/idle_u.txt
grep "4:" /tayyab/user.txt >> /tayyab/idle_u.txt
grep "5:" /tayyab/user.txt >> /tayyab/idle_u.txt

echo "IDLE Users"
echo "-------------------"
cat /tayyab/idle_u.txt