Auto suspend Linux box with xscreensaver

xscreensaver-suspend

#!/bin/bash
# suspend/sleep linux system on xscreensaver activation
#
# run the bash script in your .xsession,
# or something like .config/lxsession/LXDE/autostart for lxde

timeout=60       # After xscreensaver activated, wait timeout to suspend
read_timeout=5   # timeout for read from `xscreensaver-command -watch`

SUSPEND_BIN=/usr/sbin/pm-suspend
XSCREEN_CMD=/usr/bin/xscreensaver-command


timeout=$(($timeout/$read_timeout))
blanked=0
timer=0
#echo $timeout

# count down before suspend
do_suspend() {
    timer=$(($timer + 1))
    if [ ${timer} -ge ${timeout} ]; then
        timer=0
        sudo ${SUSPEND_BIN}
        #echo "do suspend"
    fi
    #echo "timer: ${timer}"
}

process_watch() {
    # suspend after screen blank
    while :
    do
        # read xscreensaver -watch output
        read -t ${read_timeout} input
        if [[ $? -gt 0 && $? -lt 128 ]]; then 
            break
        fi

        case "$input" in
            UNBLANK*)
                blanked=0
                timer=0
                ;;
            LOCK* | BLANK*)
                if [ ${blanked} = 0 ]; then
                    blanked=1
                    timer=0 # restart timer
                fi
                ;;
        esac
        #echo "$input $blanked"

        # we are blanked, check do_suspend
        if [ ${blanked} -gt 0 ]; then
            do_suspend
        fi
    done
}

${XSCREEN_CMD} -watch | process_watch