class SimplePortSniff

# File lib/simplePortSniff/simpleportsniff.rb, line 5
def initialize( ip, ports )
  @ip     = ip
  @ports  = ports
end

# File lib/simplePortSniff/simpleportsniff.rb, line 11
def connect( host, port, timeout = 5 )
  # Convert the passed host into structures the non-blocking calls
  # can deal with
  addr      = Socket.getaddrinfo(host, nil )
  sockaddr  = Socket.pack_sockaddr_in( port, addr[0][3] )

  Socket.new(Socket.const_get( addr[0][0]), Socket::SOCK_STREAM, 0 ).tap do |socket|
    socket.setsockopt( Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1 )

    begin
      # Initiate the socket connection in the background. If it doesn't fail
      # immediatelyit will raise an IO::WaitWritable (Errno::EINPROGRESS)
      # indicating the connection is in progress.
      socket.connect_nonblock( sockaddr )

    rescue IO::WaitWritable
      # IO.select will block until the socket is writable or the timeout
      # is exceeded - whichever comes first.
      if IO.select( nil, [socket], nil, timeout )
        begin
          # Verify there is now a good connection
          socket.connect_nonblock( sockaddr )
        rescue Errno::EISCONN
          # Good news everybody, the socket is connected!
          return "port #{port} is open"
        rescue
          # An unexpected exception was raised - the connection is no good.
          socket.close
          return "port #{port} is closed"
          #raise
        end
      else
        # IO.select returns nil when the socket is not ready before timeout
        # seconds have elapsed
        socket.close
        return "port #{port} is closed"
        #raise "Connection timeout"
      end
    end
  end
end

# File lib/simplePortSniff/simpleportsniff.rb, line 53
def sniff()
  rtn = []
  @ports.each do |item|
    rtn.push( connect( @ip, item, 1 ) )
  end
  return rtn.join("\n")
end