Control an Android phone over USB and toggle tethering

usb-phone-control.zsh

typeset -A keys
keys=(
  power 26
  home 3
  up 19
  down 20
  left 21
  right 22
  enter 66
)

function key() {
  adb shell input keyevent "${keys[$1]}"
}

function swipe-up() {
  adb shell input swipe 0 1000 0 0
}

function unlock() {
  key power
  swipe-up
}

function lock() {
  key power
}

function tethering-enabled() {
  if adb shell getprop sys.usb.config | grep rndis > /dev/null; then
    return 0
  else
    return 1
  fi
}

function open-tethering() {
  adb shell am start -n com.android.settings/.TetherSettings
}

function toggle-tethering() {
  echo -n "Toggling USB tethering status..."
  unlock
  open-tethering
  key up
  key down
  key down
  key down
  key enter
  sleep 2
  key home
  lock
  echo "Done."
}

function enable-tethering() {
  if tethering-enabled; then
    echo "USB tethering already enabled"
    return 0
  fi
  toggle-tethering
}

function disable-tethering() {
  if ! tethering-enabled; then
    echo "USB tethering already disabled"
    return 0
  fi
  toggle-tethering
}