Disable Sleep on a Mac from the Command Line with caffeinate
You’ve always been able to temporarily prevent a Mac from sleeping by using the pmset noidle command or a hot corner, but with OS X Mountain Lion, Apple has bundled a command line tool dedicated to sleep prevention much like the popular Caffeine app, and appropriately, named it caffeinate.
At it’s most simple usage, caffeinate just prevents sleep entirely, but you can modify the command with various flags to prevent just the display from sleeping, provide a specified time to avoid sleeping, prevent sleeping while a command runs, and more. A few useful examples are discussed below.
To temporarily disable sleep, run this command from Terminal:
caffeinate
You can also run caffeinate for a pre-determined amount of time to prevent sleeping, say for 4 hours while you download something, and then run it in the background by adding & to it:
caffeinate -t 144000 &
The number attached to the -t flag is the amount of time in seconds for sleep to be disabled on the Mac.
Caffeinate can also be attached to other commands to prevent the Mac from sleeping while the command runs:
caffeinate [command_to_run] -arguments
That causes the Mac to avoid sleep only as long as it takes to run the command provided, after which the normal sleep rules apply.
Heads up to MacWorld for the tip
“To temporarily disable sleep, run this command from Terminal: caffeinate”
Temporarily… How much time?
And how to turn to a normal situation?
Sleep is prevented for as long as caffeinate runs, if you stop caffeinate or kill the process it will return to normal behavior. Likewise, if you set a time limit it will only prevent sleep for the specified time before returning to normal behavior.
“Sleep is prevented for as long as caffeinate runs, if you stop caffeinate or kill the process it will return to normal behavior.”
And how to do that? Decaffeinate?
ctrl-c cancels a process running in a terminal window. or just close the terminal window.
Thanks
“To temporarily disable sleep, run this command from Terminal: caffeinate” Temporarily… How much time? And how to turn to a normal situation?
Or.. you can download Caffeine from the Mac App Store..
http://itunes.apple.com/us/app/caffeine/id411246225?mt=12
One thing that doesn’t seem to work with Caffeine (unless I’ve made a mistake..) is that, once you lock your session, it seems to stop preventing the Mac from sleeping …
It is what I was asking above: “And how to turn to a normal situation?’”
What is the terminal instruction?
decaffeinate??
MacBookPro:~ yapchinhoong$ caffeinate &
[1] 324
MacBookPro:~ yapchinhoong$ ps -ef | grep caffeinate
501 324 306 0 11:05PM ttys001 0:00.00 caffeinate
501 326 306 0 11:05PM ttys001 0:00.00 grep caffeinate
MacBookPro:~ yapchinhoong$
MacBookPro:~ yapchinhoong$ kill 324
501 330 306 0 11:05PM ttys001 0:00.00 grep caffeinate
MacBookPro:~ yapchinhoong$
MacBookPro:~ yapchinhoong$ caffeinate &
[1] 324
MacBookPro:~ yapchinhoong$ ps -ef | grep caffeinate
501 324 306 0 11:05PM ttys001 0:00.00 caffeinate
501 326 306 0 11:05PM ttys001 0:00.00 grep caffeinate
MacBookPro:~ yapchinhoong$
MacBookPro:~ yapchinhoong$ kill 324
MacBookPro:~ yapchinhoong$ ps -ef | grep caffeinate
501 330 306 0 11:05PM ttys001 0:00.00 grep caffeinate
MacBookPro:~ yapchinhoong$
I suspect you are mistaken, VDK. If I toggle Caffeine on, it stays on indefinitely, although this MBP blacks out if I move the cursor into the top right corner or if I close the lid. By control clicking the menubar icon I also have the options to stay awake for 5, 10, 15, 30, 60 or 120 minutes. Beats messing around with Command lines.
there is a much simpler command with nothing being required to be installed.
“pmset noidle” <<< as long as this terminal session is running, your computer will not sleep.
The current build of Caffeine doesn’t work properly under Mountain Lion – ML’s set sleep parameters override Caffeine’s capabilities in some instances.