lua script for wake on lan(wol)

wol.lua

#!/usr/bin/lua

if #arg ~= 2 then
  print("Usage:  wol.lua <broadcast> <mac>\n")
  os.exit()
end

local mac = ''
for w in string.gmatch(arg[2], "[0-9A-Za-z][0-9A-Za-z]") do
  mac = mac .. string.char(tonumber(w, 16))
end

local udp = require("socket").udp()
udp:settimeout(1)
udp:setoption("broadcast", true)
udp:sendto(string.char(0xff):rep(6) .. mac:rep(16) , arg[1], 9)