src/java/examples/rlogin.java

/***
 * $RCSfile: rlogin.java,v $ $Revision: 1.1 $ $Date: 2002/04/03 01:04:25 $
 *
 * NetComponents Internet Protocol Library
 * Copyright (C) 1997-2002  Daniel F. Savarese
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library in the LICENSE file; if not, write
 * to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA  02111-1307  USA
 ***/

import java.io.*;

import com.oroinc.io.*;
import com.oroinc.net.bsd.*;


/***
 * This is an example program demonstrating how to use the RLoginClient
 * class. This program connects to an rlogin daemon and begins to
 * interactively read input from stdin (this will be line buffered on most
 * systems, so don't expect character at a time interactivity), passing it
 * to the remote login process and writing the remote stdout and stderr
 * to local stdout.  If you don't have .rhosts or hosts.equiv files set up,
 * the rlogin daemon will prompt you for a password.
 * <p>
 * On Unix systems you will not be able to use the rshell capability
 * unless the process runs as root since only root can bind port addresses
 * lower than 1024.
 * <p>
 * JVM's using green threads will likely have problems if the rlogin daemon
 * requests a password.  This program is merely a demonstration and is
 * not suitable for use as an application, especially given that it relies
 * on line buffered input from System.in.  The best way to run this example
 * is probably from a Win95 dos box into a Unix host.
 * <p>
 * Example: java rlogin myhost localusername remoteusername vt100
 * <p>
 * Usage: rlogin <hostname> <localuser> <remoteuser> <terminal>
 * <p>
 ***/

// This class requires the IOUtil support class!
public final class rlogin {

  public static final void main(String[] args) {
    String server, localuser, remoteuser, terminal;
    RLoginClient client;

    if(args.length != 4) {
      System.err.println(
	 "Usage: rlogin <hostname> <localuser> <remoteuser> <terminal>");
      System.exit(1);
      return; // so compiler can do proper flow control analysis
    }

    client = new RLoginClient();

    server   = args[0];
    localuser = args[1];
    remoteuser = args[2];
    terminal  = args[3];

    try {
      client.connect(server);
    } catch(IOException e) {
      System.err.println("Could not connect to server.");
      e.printStackTrace();
      System.exit(1);
    }

    try {
      client.rlogin(localuser, remoteuser, terminal);
    } catch(IOException e) {
      try {
	client.disconnect();
      } catch(IOException f) {
      }
      e.printStackTrace();
      System.err.println("rlogin authentication failed.");
      System.exit(1);
    }


    IOUtil.readWrite(client.getInputStream(), client.getOutputStream(),
		     System.in, System.out);

    try {
      client.disconnect();
    } catch(IOException e) {
      e.printStackTrace();
      System.exit(1);
    }

    System.exit(0);
  }

}