Prevent idle sleep in a long-running bash script on Mac OS

caffeinated.md

• Add this line to the start of the script:

caffeinate -i -w $$ &

• Caffeinate is a built-in Mac OS utility for creating power management assertions to prevent sleep.
• The -i flag tells caffeinate to prevent idle sleep.
• The -w flag tells caffeinate to wait until the specified process finishes.
• $$ is a shell variable containing the current PID. Together with the -w flag this tells caffeinate to prevent sleep for the duration of the shell script.
• The final & runs the command in the background so the script can continue running.