GNOME Wi-Fi auto-wake and unlock screen

wifiUnlock.zsh

#!/bin/zsh

# SETUP
# Device MAC address
MAC="FF:FF:FF:FF:FF:FF"
# IP subnet range
RANGE="192.168.0.0/27"


timeout=1.0

setTimeout() {
    timeout="$(( $timeout * 1.1 ))"
    if [ 1 -eq "$(echo $timeout '>' 120 | bc)" ]; then
        timeout=120.0
    fi
}

while true; do
    # network device exists
    # Requires nmap to be part of user's NOPASSWD sudoers commands
    exists=$(sudo nmap -sP $RANGE | grep -iA 1 $MAC)
    if [ ! -z "$exists" ]; then
        # screensaver time active
        active=$(qdbus org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.GetActiveTime)

        if ! [ "$active" = "0" ]; then
            echo "Device unlocking. Screensaver was active for $active seconds."
            gnome-screensaver-command -d
            xset dpms force on

            # Reset timeout
            timeout=1.0

        else
            setTimeout
            # "Device found but screen is not locked ($timeout sleep)"
            sleep $timeout
        fi

    else
        setTimeout
        # "Device not found ($timeout sleep)"
        sleep $timeout
    fi
done