til/mac/prevent-sleep-with-the-caffeinate-command.md

Prevent Sleep With The Caffeinate Command

MacOS has a built-in utility caffeinate that can programatically prevent your machine from sleeping. There are two kinds of sleep that it can prevent via assertions.

caffeinate creates assertions to alter system sleep behavior.

The two kinds of sleep behavior are display sleep and system idle sleep. An assertion to prevent display sleep can be created with -d and system idle sleep with -i.

We can combine those to prevent both and then specify a duration (timeout) with -t (with a value in seconds).

caffeinate -d -i -t 600

This creates assertions with 10 minute timeouts for both display and system idle sleep.

The caffeinate command is blocking, so if you want to start it in the background, you can do that like so:

caffeinate -d -i -t 600 &

See man caffeinate for more details.