network.lua

local network = {}

local modem = require("component").modem
local event = require("event")

ip = nil -- Here he has his own IP

function network.send(dip, port, message)
   modem.open(port)
   return modem.send(network.lookup(dip),port,ip,message)
end

function network.receive(port, timeout)
  modem.open(port)
  while (true) do
    local _,_,from,fport,_,fip,data = event.pull(timeout, "modem_message")
    if(fport==port) then
      local rip = network.lookup(fip)
      if (rip==from) then
        return rip,data
      end
    end
  end
end

function network.lookup(lip)
--  print("lip: "..lip)
  modem.open(1)
  modem.broadcast(1, tostring("WHO IS " .. lip))

  while true do
    local _,_,from,port,_,data = event.pull("modem_message")
    --print("type: " ..type(data))
    if type(data)=="string" then
      --print(data)
      local x = string.find(data," ")
      local str1,str2 = string.sub(data,1,x-1),string.sub(data,x+1,#data)
      if string.sub(str2,1,2) == "IS" then
        local x = string.find(str2, " ")
        local str3,str4 = string.sub(str2,1,x-1),string.sub(str2,x+1,#str2)
        modem.close(1)
        return(str4)
      else
        print("Corrupted data")
      end

    end
  end
  modem.close(1)

end

return network