launch a program when idle, quit the program when not

[daftcain]

Hello all,

I am trying to find a way to have a specific program launch when the machine becomes idle (not when it goes to sleep), and then quits or the process is killed once the machine is not idle anymore. After looking around here it seems that a program called Senario (http://www.versiontracker.com/dyn/moreinfo/macosx/21086) would have been perfect because it describes launching or executing a script on those events, but it seems to not work with the leopard now. I know applescript can perform repeating tasks on idle, and that might work, but I can't figure out how to force quit something when the machine is no longer idle.

If you're curious purpose of all of this is to set up a render farm in an office that will not effect other peoples CPU cycles.

[trevor]

Why don't you make your render-farm application a screensaver? That automatically launches when the computer is idle and quits when the computer is no longer idle, which seems to be exactly what you want without any added fuss.

Trevor

[cwtnospam]

Can you set the priority (man nice) of the app to be low enough that it can run all the time without interfering? I run Folding@home all the time when my 4 year old Dual G5 is on, and I've never noticed a performance hit because Folding@home is set to low priority by default.

[mark hunte]

Here is an old script I had,that you can play with.

It will check the idle state every 20 seconds.
if the idle state is less than 20 seconds ( i.e a key clicked in the last 20 seconds) then it will quit in this case textedit.app.

if the idle time is more than 120 seconds ( no key clicked for a minute and half) it will launch textedit.app

property idleCheck : 20 as integer
property idleCheck_usr : 120 as integer
set timer to 0
on idle
	--Check idle time
	set idletime to do shell script "ioreg -c IOHIDSystem | awk '/HIDIdleTime/ {print int($NF/1000000000); exit}'"
	set idletime to idletime as string
	set idletime to idletime as integer
	
	tell application "System Events"
		
		
		if idletime is less than idleCheck then (* 20 is 20 seconds. If a key was  tapped 
		within the idleCheck  seconds, it  quits the app. *)
			tell application "TextEdit" to quit
			
			return idleCheck -- checks again in ... seconds
		else
			if idletime is greater than idleCheck_usr then (*  If a key was tapped 
		after the idleCheck_usr  seconds it t opens the app. *)
				tell application "TextEdit" to launch
				
			end if
			
			return idleCheck -- 
			
		end if
		
	end tell
end idle

[daftcain]

Thanks for the replies, I'm sure one of these will work. The simplest sounds like making the app a screen saver, but I don't exactly see a way to choose the application from within the screen saver system preferences. Do I have to change the program in some way so it shows up as a screen saver?

looks like any of the other solutions can work too

[trevor]

Quote: Originally Posted by daftcain Thanks for the replies, I'm sure one of these will work. The simplest sounds like making the app a screen saver, but I don't exactly see a way to choose the application from within the screen saver system preferences. Do I have to change the program in some way so it shows up as a screen saver? looks like any of the other solutions can work too

There's probably a more elegant way to make an app directly into a screensaver, but one method to make this work is to use ScriptSaver, which is a screensaver that will launch an Applescript. If that Applescript launches your app, that should work to start the app, although I'm not sure about automatically quitting your app when the computer ceases to be idle.

Trevor