package primer7;

import java.net.*;
import java.io.*;

public class PortScanner {

	public static void main(String[] args) {

		String host = "localhost";

		if (args.length > 0)
			host = args[0];

		try {
			InetAddress theAddress = InetAddress.getByName(host);

			for (int i = 1; i < 65536; i++) {
				Socket connection = null;
				try {
					connection = new Socket(theAddress, i);
					System.out.println("There is a server on port " + i + " of " + host);
				} catch (IOException ex) {
				} finally {
					try {
						if (connection != null)
							connection.close();
					} catch (IOException ex) {
					}
				}

			}

		} catch (UnknownHostException ex) {
			System.err.println(ex);
		}

	}

}