Our cellar houses an old grey box that acts as a home server for the family. It's quite useful in a number of ways, as a file server, web server, database server, and so on. It also, traditionally, had a habit of wasting power—it's so much nicer to just have the machine running when you use it. But, with the wonders of Wake on LAN, even the “I'm too lazy to run into the cellar” argument has lost any validity it might have had.
So much for turning the box on, how about turning it off? Figuring out when nobody is using the machine and then remembering to turn it off as well is hardly a task for a mere mortal. So I wrote a script that does it for me.
is_anyone_here.py checks whether anyone is logged in, and looks for any evidence of recent usage. It was written on/for a Debian GNU/Linux (lenny) system with vsftpd and samba, and may require some modifications to work properly in your environment.
Have a look at the whole script after the break.