Auto Shutdown

[Caithness]

FreeBSD is fast becoming my favourite OS,
though I'm fairly new to it.
I would like to auto shutdown after 30 minutes of inactivity.
I can create a cron job, but don't know what to put in it.
Any help is greatly appreciated.
Cheers

 

[ProFTP]

to write a demon which will look the started processes in top, ignore the process on id...
if nothing is included, in a process, to turn off (can ignore system utilities)

 

[ale]

Maybe you can check with last | grep "still logged in".