[csc376] SlowPortScan

val openPorts : List[Int] = (for (port <- (0 to 1023).toList) yield {
        tryIgnore ( List[Int] () ) {
          tryfinally (new Socket (addr, port)) { s => List (port) }
        }
      }).flatten
      println ("open ports on %s: %s".format (addr, openPorts))