function on_msg_receive (msg)
  if msg.out then
    return
  end
  if ((msg.text=='/purple') or (msg.text=='/p')) then
    local file = io.open("/home/pi/git/lights/tglog.txt", "w")
    local timestr = os.date("%Y/%m/%d-%H:%M:%S")
    local message = ("purple|" .. timestr .. "|")
    send_msg (msg.from.print_name, message, ok_cb, false)
    file:write("purple|", timestr, "\n")
    file:close()
  end
end
 
function on_our_id (id)
end
 
function on_secret_chat_created (peer)
end
 
function on_user_update (user)
end
 
function on_chat_update (user)
end
 
function on_get_difference_end ()
end
 
function on_binlog_replay_end ()
end