Thinstation Lock screens

[CyberNerd]

I'm thinking outloud...

Outcome I want...
Teachers to be able to 'lock' and 'unlock' screens of entire classrooms.

what I have (almost, I need to finish some bits)

DHCP server with mac's and IP addresses for classrooms
PXE booting thinstation
Citrix ICA client
ssh client on thinstation
ip address of clients
script that will log into all clients in a classroom as root (nearly)
web interface that allows teachers to do XYZ to the thinstation (ok, I'm no-where near doing this yet)

what I need...
suggestions. AFIK citrix can't lock the session?. Can my X server be told to lock and restart the session from ssh ? how?
TIA

[Geoff]

Assuming they have xscreensaver running:

xscreensaver-command -lock

however there's no equivelent unlock command. Plus it'll nag for a (probably no existant) local user password to unlock it.

You might be better off with

xscreensaver-command -activate

xscreensaver-command -deactivate

Which also blanks/unblanks the screen but with out any locking.

[CyberNerd]

Thanks
I tried on my machine and that almost worked perfectly, but I got the problems you described.
what about remotely activating xcreensaver and simultaneously locking the kb/mouse ? any suggestions?

[Geoff]

There is no way to disable the keyboard/mouse input AFAIK.

[CyberNerd]

got it...

Run

 xscreensaver-command -lock [

to lock the screen
remotely kill the xscreensaver process to unlock the screen tehn restart the xscreenserver daemon.

Thanks for your help, just got to work on getting xscreensaver in thinstation. doh.

[Geoff]

You don't need to kill it. I think:

xscreensaver-command -restart

Will work.

[CyberNerd]

thanks, but I tried - it won't restart if the screen is locked.

[Geoff]

How about:

xscreensaver-command -exit

[CyberNerd]

same thing:

xscreensaver-command: screen is locked

[Geoff]

Fair enough. 'kill -9' it is.