#!/usr/bin/lua
print("Content-type: text/html\n")
print("<HTML><HEAD><TITLE>Relay control</TITLE>")
print("</HEAD><BODY>")
local f = io.open("/dev/ttyACM0", "r+")
f:write("quiet\n")
if os.getenv("QUERY_STRING"):upper() == "ON" then
  f:write("D0=1\n")
  print("Relay is now on.")
elseif os.getenv("QUERY_STRING"):upper() == "OFF" then
  f:write("D0=0\n")
  print("Relay is now off.")
else
  print("Error.")
end
f:close()
print("</BODY></HTML>\n")
