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ReefHobbyist · Jan 21, 2003, 01:43 PM

Is it possible to have a screensaver active for the login window?

The energy saver preferences seem to be global and I have it set to 60mins for putting the screen to sleep.

The screen saver preferences, however, appear to be user specific. I have mine set to 10mins. When I log out the screen stays active for the entire 60mins before the screen goes to sleep.

Can I setup a screen saver for the login window? (root maybe?)

Thanks,
Scott

fitter · Jan 21, 2003, 02:55 PM

There's no screensaver for the login window, currently. This has been a big issue for public labs at colleges and universities, because the login window will burn on to the screen if no one uses the machine for a long period of time. Apple has not provided a solution yet. There is this, though:

Screen Preserver

Essentially, you set up a cron job to execute a script that checks to see if anyone's logged into the console. If not, the Screen Preserver is launched, preventing the login window from burning on to the screen. When you move or click the mouse, or press a key, it exits, allowing you to login.

drcarl · Mar 29, 2003, 12:19 PM

I was looking for a solution to this problem too. Think I'll give it a try. Thank you fitter!

drcarl · Mar 29, 2003, 01:25 PM

OK, I started to install Screen Preserver, but I got hung-up on adding a cron job. The README.txt file doesn't do an adequate job at explaining how to do this. I checked the man entry for cron and crontab, but I'm still not sure what to do.

Screen Preserver.app is installed in my Utilities folder as recommended, but the console_check script is not stored on my hard disk yet (didn't know where to put it). My 'Pictures' folder is set-up with a few images in it. I would like Screen Preserver to activate after 3 minutes. Any help would be appreciated.

fitter · Mar 29, 2003, 10:59 PM

The cron stuff is probably most difficult. Check out Cronnix for an easy way to set up cron jobs. Once you've got Cronnix, run it, and select "Open System Crontab" from the File menu. Click "New" in the toolbar. In the sheet that drops down, change the Minute field to read */3 (this means run the command every 3 minutes). In the Command field, type /usr/local/bin/console_check. Save your changes and quit Cronnix.

Now all you have to do is put the console_check script in /usr/local/bin. By default the directory /usr/local/bin does not exist on OS X. Create like this:

sudo mkdir /usr/local/bin

Once that's done, copy the console_check script to /usr/local/bin, like so:

cd /Volumes/Screen\ Preserver
sudo cp console_check /usr/local/bin

(This assumes you have the Screen Preserver disk image mounted.)

That should be it.

Cipher13 · 05:04 AM

Image burning isn't really much of an issue anymore...

OptimusG4 · Mar 30, 2003, 05:29 AM

Originally posted by Cipher13:
Image burning isn't really much of an issue anymore...

Not to mention you can have the screen go dark after a minute via the Energy Saver Prefs..and it even works on the login screen.

Geobunny · Mar 30, 2003, 10:50 AM

Originally posted by Cipher13:
Image burning isn't really much of an issue anymore...

Admittedly not, but it's nice to have a corporate logo flying about when no-one's using the machine.

Jazzphone · Mar 30, 2003, 12:48 PM

Image burner isnt at all a concern any more, The monitors available today have gotten rid of that funny little things *Looks at his old RadioShack Tandy With the C

.... Burned on to the Screen* But yeah it is nice to ahve the logo going but just for eye candy, not for safety.

OwlBoy · Mar 30, 2003, 03:36 PM

What would be �ber-cool is running the screensave behind the login window

-Owl

msuper69 · Mar 30, 2003, 03:48 PM

Originally posted by OwlBoy:
What would be �ber-cool is running the screensave behind the login window

-Owl

The SETI client for OS X does just that.

drcarl · Mar 30, 2003, 04:22 PM

Wow... thanks for the detailed instructions fitter.

I'll install Screen Preserver and let you know how it goes.

fitter · Mar 30, 2003, 09:57 PM

Originally posted by Cipher13:
Image burning isn't really much of an issue anymore...

The issue's not burn-in, but ghosting on flat-panel machines. If you don't set the preferences to dim the screen after a certain interval, a ghost of the login panel remains on the screen. It doesn't appear in screenshots, but is definitely visible to the user. I don't know the reasons for this behaviour, but it's a real issue, especially at universities running 24-hour labs, where the option of dimming the screen is nixed because students tend to look at a darkened monitor and assume the computer is broken. (Honest.)

WJMoore · Mar 30, 2003, 10:41 PM

Originally posted by fitter:
There's no screensaver for the login window, currently. This has been a big issue for public labs at colleges and universities, because the login window will burn on to the screen if no one uses the machine for a long period of time. Apple has not provided a solution yet. There is this, though:

Screen Preserver

Essentially, you set up a cron job to execute a script that checks to see if anyone's logged into the console. If not, the Screen Preserver is launched, preventing the login window from burning on to the screen. When you move or click the mouse, or press a key, it exits, allowing you to login.

Is there any information about Screen Preserver anywhere else but on that disk image? Google and VersionTracker come up with nothing. I can't open disk images at uni and was just hoping to read some info. How did you know about it? There doesn't seem to be any links anywhere to it.

Wesley

moonmonkey · Mar 30, 2003, 10:52 PM

Originally posted by WJMoore:
Is there any information about Screen Preserver anywhere else but on that disk image? Google and VersionTracker come up with nothing. I can't open disk images at uni and was just hoping to read some info. How did you know about it? There doesn't seem to be any links anywhere to it.

Wesley

Yes, sames problem here, at work on a bloody pc.

wadesworld · Mar 31, 2003, 12:56 AM

but it's a real issue, especially at universities running 24-hour labs, where the option of dimming the screen is nixed because students tend to look at a darkened monitor and assume the computer is broken. (Honest.)

The cynic in me says they deserve to fail the class if they can't figure out how to wake a computer.

Let them try again next semester to see if they can figure it out.

Wade

RBattin · Mar 31, 2003, 01:19 AM

Written by Andrew Mortensen
Research Systems Unix Group
University of Michigan
Based loosely on the iHook source
http://rsug.itd.umich.edu/software/ihook

moonmonkey · Mar 31, 2003, 02:13 AM

Originally posted by OwlBoy:
What would be �ber-cool is running the screensave behind the login window

-Owl

Panther does this.

Detrius · Mar 31, 2003, 02:27 AM

Originally posted by OwlBoy:
What would be �ber-cool is running the screensave behind the login window

-Owl

SETI@Home does this already.

drcarl · 01:26 AM

Well, I did it. A couple of hurdles:

At the first try, it did not work. I got it to work by clicking on the 'Experts' tab in CronniX and setting minutes to '/*3' and setting all the other fields (e.g. hours, days, etc.) to '*'. I'm guessing that the '*' stands for 'any'.

I origionally placed aliases to the images that I wanted displayed in the 'Pictures' folder but that just displayed a blank screen. After putting the actual images into the 'Pictures' folder, everything seems to work.

By running every 3 minutes, am I going to notice any performance decrease or unnecessary wear on my hard drive? I have 1 Gig of RAM, so I was hoping that cron just hangs out in RAM instead of having to be loaded from the hard drive a milliion times.

Again, thanks fitter and MacNN. Macs RULE!

edddeduck · Apr 1, 2003, 10:17 AM

Originally posted by wadesworld:
The cynic in me says they deserve to fail the class if they can't figure out how to wake a computer.

Let them try again next semester to see if they can figure it out.

Wade

Nah they should be asked to walk into an open lift shaft from the 30th floor. Those type of people just waste oxygen.

Cheers Edwin

fitter · Apr 1, 2003, 11:32 AM

Originally posted by drcarl:

By running every 3 minutes, am I going to notice any performance decrease or unnecessary wear on my hard drive? I have 1 Gig of RAM, so I was hoping that cron just hangs out in RAM instead of having to be loaded from the hard drive a milliion times.

No, cron's already running in the background, and has been as long as you've been running Mac OS X. It starts when the machine starts up.

Since the little script (console_check) that gets called only runs a very light set of commands, and only launches the Screen Preserver if no one's logged in, I expect you won't see any change in performance.

hadocon · Apr 1, 2003, 11:31 PM

Originally posted by Cipher13:
Image burning isn't really much of an issue anymore...

It is if you use an LCD display.