[SOLVED] Turn screens on and off via SSH

battler · 06-11-2012, 02:54 AM

I'm a teacher and I have 24 computers for my students. They all run Ubuntu 12.04 and I have SSH root access. I would like to disable their screens via DPMS but somehow this doesnt work anymore.

I use the commando:

Code:

sudo xset dpms force off

But I get the error:

Code:

 xset:  unable to open display ""

I've read some threads about X forwarding, but this is not what I want. I just want to disable their screens until I turn them on again.

Solved:

Code:

 Right command is xset -d :0 dpms force [on/off]

This gives the same error but works nonetheless.

acid_kewpie · 06-11-2012, 03:03 AM

//removing from zero posts.

battler · 06-11-2012, 03:44 AM

Too bad this only works in Ubuntu 11.10 , Ubuntu 12.04 gives the following error with the new command.

Code:

Invalid MIT-MAGIC-COOKIE-1 keyInvalid MIT-MAGIC-COOKIE-1 keyxset:  unable to open display ":0"

I remove the ~/.Xauthority* file but dint change a thing. The users log in as student, I log in via SSH as teacher (root permission).

SOLVED: In ubuntu 12.04

Code:

 sudo vbetool dpms [on/off]

works!