Run script on system idle

Question

I want to run some servers and whatnot on my machine but I don't want it to interfere with what I'm doing... Gaming, research, writing a paper, etc. My thought was to have a script run when the system idles as in when the screen is locked or no users are logged in. The stuff I would be running during idle would be things like a plex server, bitcoin miner or bittorrent. I can start and stop all of these things with something like "service plexd start/stop". Any ideas on how I can initiate these commands when the system goes into and comes out of idle?

Answer 1

I've created a new script to run a command upon locking and unlocking the screen because the others on the web don't work on 14.04. I set it as a startup program and added it to my sudoers file so that it can manage services on its own.

#!/bin/bash
while sleep 30s ; do
   state=$(gnome-screensaver-command --query | grep -o "\w*active\w*" >> /dev/null)
   if [[ $state == active ]]
   then
        ./start.sh
   else
        ./stop.sh
   fi
done