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1   /*
2    * Copyright 2001-2005 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.net.bsd;
17  
18  import java.io.IOException;
19  
20  /***
21   * RLoginClient is very similar to
22   * {@link org.apache.commons.net.bsd.RCommandClient},
23   * from which it is derived, and uses the rcmd() facility implemented
24   * in RCommandClient to implement the functionality of the rlogin command that
25   * first appeared in 4.2BSD Unix.  rlogin is a command used to login to
26   * a remote machine from a trusted host, sometimes without issuing a
27   * password.  The trust relationship is the same as described in
28   * the documentation for
29   * {@link org.apache.commons.net.bsd.RCommandClient}.
30   * <p>
31   * As with virtually all of the client classes in org.apache.commons.net, this
32   * class derives from SocketClient.  But it relies on the connection
33   * methods defined  in RcommandClient which ensure that the local Socket
34   * will originate from an acceptable rshell port.  The way to use
35   * RLoginClient is to first connect
36   * to the server, call the {@link #rlogin  rlogin() } method,
37   * and then
38   * fetch the connection's input and output streams.
39   * Interaction with the remote command is controlled entirely through the
40   * I/O streams.  Once you have finished processing the streams, you should
41   * invoke {@link org.apache.commons.net.bsd.RExecClient#disconnect disconnect() }
42   *  to clean up properly.
43   * <p>
44   * The standard output and standard error streams of the
45   * remote process are transmitted over the same connection, readable
46   * from the input stream returned by
47   * {@link org.apache.commons.net.bsd.RExecClient#getInputStream getInputStream() }
48   * .  Unlike RExecClient and RCommandClient, it is
49   * not possible to tell the rlogind daemon to return the standard error
50   * stream over a separate connection.
51   * {@link org.apache.commons.net.bsd.RExecClient#getErrorStream getErrorStream() }
52   *  will always return null.
53   * The standard input of the remote process can be written to through
54   * the output stream returned by
55   * {@link org.apache.commons.net.bsd.RExecClient#getOutputStream getOutputSream() }
56   * .
57   * <p>
58   * <p>
59   * @author Daniel F. Savarese
60   * @see org.apache.commons.net.SocketClient
61   * @see RExecClient
62   * @see RCommandClient
63   ***/
64  
65  public class RLoginClient extends RCommandClient
66  {
67      /***
68       * The default rlogin port.  Set to 513 in BSD Unix and according
69       * to RFC 1282.
70       ***/
71      public static final int DEFAULT_PORT = 513;
72  
73      /***
74       * The default RLoginClient constructor.  Initializes the
75       * default port to <code> DEFAULT_PORT </code>.
76       ***/
77      public RLoginClient()
78      {
79          setDefaultPort(DEFAULT_PORT);
80      }
81  
82  
83      /***
84       * Logins into a remote machine through the rlogind daemon on the server
85       * to which the RLoginClient is connected.  After calling this method,
86       * you may interact with the remote login shell through its standard input
87       * and output streams.  Standard error is sent over the same stream as
88       * standard output.  You will typically be able to detect
89       * the termination of the remote login shell after reaching end of file
90       * on its standard output (accessible through
91       * {@link #getInputStream  getInputStream() }.  Disconnecting
92       * from the server or closing the process streams before reaching
93       * end of file will terminate the remote login shell in most cases.
94       * <p>
95       * If user authentication fails, the rlogind daemon will request that
96       * a password be entered interactively.  You will be able to read the
97       * prompt from the output stream of the RLoginClient and write the
98       * password to the input stream of the RLoginClient.
99       * <p>
100      * @param localUsername  The user account on the local machine that is
101      *        trying to login to the remote host.
102      * @param remoteUsername  The account name on the server that is
103      *        being logged in to.
104      * @param terminalType   The name of the user's terminal (e.g., "vt100",
105      *        "network", etc.)
106      * @param terminalSpeed  The speed of the user's terminal, expressed
107      *        as a baud rate or bps (e.g., 9600 or 38400)
108      * @exception IOException If the rlogin() attempt fails.  The exception
109      *            will contain a message indicating the nature of the failure.
110      ***/
111     public void rlogin(String localUsername, String remoteUsername,
112                        String terminalType, int terminalSpeed)
113     throws IOException
114     {
115         rexec(localUsername, remoteUsername, terminalType + "/" + terminalSpeed,
116               false);
117     }
118 
119     /***
120      * Same as the other rlogin method, but no terminal speed is defined.
121      ***/
122     public void rlogin(String localUsername, String remoteUsername,
123                        String terminalType)
124     throws IOException
125     {
126         rexec(localUsername, remoteUsername, terminalType, false);
127     }
128 
129 }