A sleep runner for macos

sleep-runner.sh

# This prevents a macos/osx computer even when the lid is closed to prevent it going to sleep in a multi desktop set-up
# based off https://apple.stackexchange.com/users/9058/nohillside 's answer at https://apple.stackexchange.com/questions/219885/use-caffeinate-to-prevent-sleep-on-lid-close-on-battery
# store in /user/local/bin
#! /bin/bash
BATTERY_SLEEP=5 # in minutes
DEF_WAKE_LEN=32400 # in seconds - I'm on my computer for 9 hours usually

#***** determine timeout value *****
timeout_len=${DEF_WAKE_LEN:-32400} # see also https://unix.stackexchange.com/questions/122845/using-a-b-for-variable-assignment-in-scripts

# trap ctrl-c and call ctrl_c()
trap enable_sleep INT

function enable_sleep() {
    # $1: <enter> = 0, timeout = 1, Ctrl-C = undef

    #----- insert a newline for timeout or Ctrl-C -----
    if [[ ${1:-1} -eq 1 ]]; then    echo; fi
    echo "Restoring previous battery sleep setting: $BATTERY_SLEEP"
    echo "\n"

    sudo pmset -b disablesleep 0
    sudo pmset -b sleep $BATTERY_SLEEP

    #----- sleep on timeout only -----
    if [[ ${1:--1} -eq 1 ]]; then   sudo pmset sleepnow; fi
    exit
}

function prevent_sleep() {
    echo
    echo -n "Preventing sleep for $timeout_len seconds; press [^C] to restore settings and quit..."
    echo "\n"

    sudo pmset -b disablesleep 1
    sudo pmset -b sleep 0
    sleep $timeout_len
    enable_sleep
}

prevent_sleep