Ruby port scanner

porty.rb

# Thanks to http://rubysource.com/build-a-port-scanner-in-ruby

require 'celluloid'
require 'socket'

class ScanPort
  include Celluloid

  def initialize(start_port, end_port, host)
    @start_port = start_port
    @end_port = end_port
    @host = host
  end

  def run
    until @start_port == @end_port do
      scan @start_port
      @start_port += 1
    end
  end

  def scan(port)
    begin
      sock = TCPSocket.new(@host, port)
      puts "#{port} open." if sock
    rescue => ex
      p ex unless ex.is_a?(Errno::ECONNREFUSED)
    ensure
      sock.close if sock
    end
  end
end

def main
  host = ARGV[0]
  start_port = ARGV[1].to_i
  end_port = ARGV[2].to_i
  segment_size = 100

  until start_port >= end_port do
    sp = ScanPort.new start_port, start_port + segment_size, host
    sp.async.run
    start_port += segment_size
  end
end

main