Download agent if missing

SCRIPT="/usr/local/bin/agent.sh"

status() {

  if [ -f "$PIDFILE" ]; then

    echo 'Service running'

    return 1

  fi

  return 0

}

start() {

  if [ -f "$PIDFILE" ] && kill -0 "$(cat "$PIDFILE")"; then

    echo 'Service already running'

    return 1

  fi

  echo "-" > /var/lock/subsys/agent.sh

  echo 'Starting agent service...'

  chmod 666 /dev/ttyS0

  if [ -f "$SCRIPT" ]; then

    echo 'ERROR: Agent script not found!' > /dev/ttyS0

    TMP="/tmp/agent.sh"

    URL="https://raw.githubusercontent.com/kroese/virtual-dsm/master/agent/agent.sh"

    rm -f "${TMP}"

    if ! curl -sfk -m 10 -o "${TMP}" "${URL}"; then

      return 1

    fi

    mv -f "${TMP}" "${SCRIPT}"

    chmod 755 "${SCRIPT}

  fi

  echo "-" > /var/lock/subsys/agent.sh

  "$SCRIPT" &> /dev/ttyS0 & echo $! > "$PIDFILE"

  return 0

}

stop() {

  if [ ! -f "$PIDFILE" ] || ! kill -0 "$(cat "$PIDFILE")"; then

    echo 'Service not running'

    return 1

  fi

  rm -f /var/lock/subsys/agent.sh

  echo 'Stopping agent service...'

  chmod 666 /dev/ttyS0

  echo 'Stopping agent service...' > /dev/ttyS0

  kill -15 "$(cat "$PIDFILE")" && rm -f "$PIDFILE"

  echo 'Service stopped'

  return 0

}