Programmatic control of screen-saver

Matthew Seaman m.seaman at
Wed Nov 12 07:11:07 PST 2003

On Wed, Nov 12, 2003 at 11:33:07PM +1030, Malcolm Kay wrote:
> I have a machine controlling a tester. Tester control and display is via a 
> virtual console terminal. (X is not installed on the machine)
> I need to blank the screen (screen saver style) when there is no terminal
> activity for some time -- much the same as as normal screen-saver 
> operation except that screen output as well as keyboard input should
> inhibit the screen-saver taking over or cause the normal terminal display
> to be restored if the saver is already in effect.
> I would hope that there might be some ioctl call to the terminal which 
> could be used from within the tester control software to wake up the 
> terminal or prevent the screen saver taking over until a further timeout
> has elapsed. I've not been able to find such an ioctl call parameter.
> Does anyone have any ideas or a solution please?

See vidcontrol(1):

    # vidcontrol -t 30

sets the console screensaver timeout to 30s, and

    # vidcontrol -t off

turns off the console screensaver.  This does indeed operate using the
CONS_BLANKTIME ioctl -- see the code in the set_screensaver_timeout()
function in /usr/src/usr.sbin/vidcontrol/vidcontrol.c and the
<sys/consio.h> header file.

I think that ioctl should do what you want, although I'm not sure that
setting the blanking time to zero would actually cancel a running
screen saver.



Dr Matthew J Seaman MA, D.Phil.                       26 The Paddocks
                                                      Savill Way
PGP:         Marlow
Tel: +44 1628 476614                                  Bucks., SL7 1TH UK
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