Find Idle time on Linux

How to get idle time on linux?

To clean the mess you left on computer, run screensaver or shut down unoccupied computer get idle time and run script that do things when computer become idle.

Time when no movement of mouse/other input occured) can be obtained with looping script that check on mouse movements nad run command when there was no movement in some period of time:

#!/bin/bash
sleep 60

rm mousemovementsfile
#erase file from previous session

sleep 1

#thread writing mousemovements to file -check your inputs

cat -n /dev/input/by-path/pci-0000:00:1d.7-usb-0:2.1:1.0-event-mouse > mousemovementsfile&

while (true)

do

#check size

filesize1=$(stat -c%s "mousemovementsfile")

#wait 70 second or something

sleep 600

#check second size,compare, execute idle scritp if same size

filesize2=$(stat -c%s "mousemovementsfile")

#compare

if [ "$filesize1" -eq "$filesize2" ]

then

#execute idle script

/usr/bin/notify-send -u normal -t 7000 \

      'this is only running when user is not present at computer' 'this is only running when user is not present at computer'

fi

echo notidle

done

alternative solution in c language:
via http://coderrr.wordpress.com/2008/04/20/getting-idle-time-in-unix/#comments