Shell Programming and Scripting

Hi all,

Is there a way, on the command line, to show a black screen WITHOUT turning off the monitor? Also, is there a way to make the computer show the last screen before the black screen as soon as the user interacts with it?

I know that there are various ways to turn off the computer, or turn off the monitor, but neither of those do exactly what I want. The hardware I'm working with must remain on -- it's a pain, but it's a requirement.

If anyone could help me out, I'd appreciate it.

Thanks,
Zel2008

It might help to know what your system actually is...

OK. It's an Ubuntu system, 13.04 I believe. I don't know the monitor specifications, is that necessary?

This describes the timeout settings in more detail:

display - Ubuntu 12.10 "Turn screen off when inactive for: Never" still turns off - Ask Ubuntu

And to force it off yourself, you can do sleep 1; xset dpms force off It should wake on interacted with.

I don't think this is quite what I'm looking for. I want the screen to show a black screen, but I don't want the monitor to turn off. From what I understand after doing some research, the command you gave me will turn off the monitor completely, not create a black screen.

Maybe you do understand. Really well. But the requirements writer did not.

The tty device for the monitor is still there when it is asleep. What your requirement really is: somebody likes the way you can have monitors "sleep" in windows and wants you to emulate it in ubuntu. It is a security feature as well as a power saver.

And the person creating the requirement does not know what having monitors "sleep" means exactly. If the monitor were "off" then hitting the keyboard would have no effect whatsoever. The monitor would stay black.

100% right Jim, that's exactly what I need to do. Basically, we're rewriting a Windows application to run on Linux, so I'm supposed to emulate that functionality of being able to go idle and then wake up.

A little more detail -- the way I'm required to do this is through a web page connected to the computer via a tablet, so somehow I need to figure out how to make the computer go idle, and be able to wake it up from idle. The only way I can think of to do this is to call a command line script from PHP,

But, that brings us back to square one -- there are a million commands to turn off the monitor, but nothing to go idle. I don't care if I have to write a complicated script (as long as I can get a good idea of where to start, which I still don't have), but I don't really have a choice here in reinventing the wheel, do I?