dc2

local range = 1
local height = 3
local doorx = nil
local doory = nil
local doorz = nil
local doorlog = 0
local users = {}
local close = 0
rednet.open("bottom")

while not doorx do
  doorx,doory,doorz = gps.locate()

  if not doorx then
    print("error, cant find doors location")
  else
    print("doors location: "..doorx..", "..doory..", "..doorz)
  end
end

function inRange(num,num2,min,max)
  local numdif = num - num2
  if numdif > min and numdif < max then
    return true
  else
    return false
  end
end

function checkPos(index)
  --data = textutils.unserialize(users[index])
  local message = users[index]
  data = textutils.unserialize(message)
  --print(message[1])
  if inRange(data[1],doorx,-range,range) and inRange(data[2],doory,-height,height) and inRange(data[3],doorz,-range,range) then
    close = close +1
    --print("Door opened for "..data[4].." "..close)

  end
end

function getMessage(timeout)
  --users = {}
  local senderId, packet, protocol = rednet.receive("GCP",timeout)
  if senderId and protocol == "GCP" then

    users[senderId] = packet

    --print(" "..senderId.."stored to users")
    return true
  else
    return false
  end
end

function printsomthing(index)
  --print(index)
end

while true do
  if getMessage(5) then

    table.foreach(users, checkPos)
    table.foreach(users, printsomthing)

    if close > 0 then
      --print("close="..close)
      redstone.setOutput("left",false)
      redstone.setOutput("right",false)
    else
      --print("far="..close)
      redstone.setOutput("left",true)
      redstone.setOutput("right",true)
    end
    close = 0
  else
    print("timeout, no location ping received")
    redstone.setOutput("left",true)
    redstone.setOutput("right",true)
  end
end