[ale] prevent shutdown when users logged in via ssh/nx?

[rs at ale.spam.futz.org]

I'm the remote admin for my mother-in-law's computer, which is running ubuntu.
She uses it infrequently, so I have scripts to IM me when she boots it up, so
I can do updates and such.

The problem is that often she'll shutdown before I'm finished, and I get
booted off.

If I leave a console login active and try and shut-down via the gnome gui, I
get a dialog about other users being logged in. However, this doesn't appear
to happen if I'm logged in via ssh, or even if I've got an gnome session via
nxclient.

I'm looking for a way to be able to prevent a shutdown while I'm logged in. I
suppose I could write a script to replace the shutdown command, and check for
other sessions before actually shutting down.  Anyone got any other ideas?


Robert