Coffeescript network scanner

Prototype that searches a network/subnet for a IPs that have a specific port open.

net = require 'net'
readline = require 'readline'
Socket = net.Socket
rl = readline.createInterface
  input: process.stdin
  output: process.stdout

class main
  rl.question "PORT?  ", (res) ->
    PORT = res
    rl.question "RANGE? ", (res) ->  
      LAN = res
      rl.question "TIMEOUT?  ", (res) ->
        TIMEOUT= res
        console.log "\n*----- STARTING SCAN -----*\n"
        new portscan PORT, LAN, TIMEOUT
        rl.close()

class portscan extends main
  constructor:(port, host, timeout) ->
    scan=(p, h, tt) ->
      tcp = new Socket()
      status = null
      tcp.setTimeout tt
      tcp.on "connect", ->
        status = "open"
        tcp.end()
      tcp.on "timeout", -> tcp.destroy()
      tcp.on "error", -> status = "closed"
      tcp.on "close", -> console.log h if status is "open"
      tcp.connect p, h
    i = 1
    while i <= 255
      new scan port, host+ "." + i, timeout
      i++