001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package examples;
019    
020    import java.io.IOException;
021    import org.apache.commons.net.bsd.RLoginClient;
022    
023    /***
024     * This is an example program demonstrating how to use the RLoginClient
025     * class. This program connects to an rlogin daemon and begins to
026     * interactively read input from stdin (this will be line buffered on most
027     * systems, so don't expect character at a time interactivity), passing it
028     * to the remote login process and writing the remote stdout and stderr
029     * to local stdout.  If you don't have .rhosts or hosts.equiv files set up,
030     * the rlogin daemon will prompt you for a password.
031     * <p>
032     * On Unix systems you will not be able to use the rshell capability
033     * unless the process runs as root since only root can bind port addresses
034     * lower than 1024.
035     * <p>
036     * JVM's using green threads will likely have problems if the rlogin daemon
037     * requests a password.  This program is merely a demonstration and is
038     * not suitable for use as an application, especially given that it relies
039     * on line buffered input from System.in.  The best way to run this example
040     * is probably from a Win95 dos box into a Unix host.
041     * <p>
042     * Example: java rlogin myhost localusername remoteusername vt100
043     * <p>
044     * Usage: rlogin <hostname> <localuser> <remoteuser> <terminal>
045     * <p>
046     ***/
047    
048    // This class requires the IOUtil support class!
049    public final class rlogin
050    {
051    
052        public static final void main(String[] args)
053        {
054            String server, localuser, remoteuser, terminal;
055            RLoginClient client;
056    
057            if (args.length != 4)
058            {
059                System.err.println(
060                    "Usage: rlogin <hostname> <localuser> <remoteuser> <terminal>");
061                System.exit(1);
062                return ; // so compiler can do proper flow control analysis
063            }
064    
065            client = new RLoginClient();
066    
067            server = args[0];
068            localuser = args[1];
069            remoteuser = args[2];
070            terminal = args[3];
071    
072            try
073            {
074                client.connect(server);
075            }
076            catch (IOException e)
077            {
078                System.err.println("Could not connect to server.");
079                e.printStackTrace();
080                System.exit(1);
081            }
082    
083            try
084            {
085                client.rlogin(localuser, remoteuser, terminal);
086            }
087            catch (IOException e)
088            {
089                try
090                {
091                    client.disconnect();
092                }
093                catch (IOException f)
094                {}
095                e.printStackTrace();
096                System.err.println("rlogin authentication failed.");
097                System.exit(1);
098            }
099    
100    
101            IOUtil.readWrite(client.getInputStream(), client.getOutputStream(),
102                             System.in, System.out);
103    
104            try
105            {
106                client.disconnect();
107            }
108            catch (IOException e)
109            {
110                e.printStackTrace();
111                System.exit(1);
112            }
113    
114            System.exit(0);
115        }
116    
117    }
118