Commons Net example source code file (rlogin.java)

This example Commons Net source code file (rlogin.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Net tags/keywords

io, ioexception, ioexception, rloginclient, rloginclient, string, string, usage, usage

The Commons Net rlogin.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package examples.unix;

import java.io.IOException;
import org.apache.commons.net.bsd.RLoginClient;

import examples.util.IOUtil;

/***
 * 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>   
 * <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>   ");
            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);
    }

}