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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.net.bsd;
19  
20  import java.io.IOException;
21  
22  /***
23   * RLoginClient is very similar to
24   * {@link org.apache.commons.net.bsd.RCommandClient},
25   * from which it is derived, and uses the rcmd() facility implemented
26   * in RCommandClient to implement the functionality of the rlogin command that
27   * first appeared in 4.2BSD Unix.  rlogin is a command used to login to
28   * a remote machine from a trusted host, sometimes without issuing a
29   * password.  The trust relationship is the same as described in
30   * the documentation for
31   * {@link org.apache.commons.net.bsd.RCommandClient}.
32   * <p>
33   * As with virtually all of the client classes in org.apache.commons.net, this
34   * class derives from SocketClient.  But it relies on the connection
35   * methods defined  in RcommandClient which ensure that the local Socket
36   * will originate from an acceptable rshell port.  The way to use
37   * RLoginClient is to first connect
38   * to the server, call the {@link #rlogin  rlogin() } method,
39   * and then
40   * fetch the connection's input and output streams.
41   * Interaction with the remote command is controlled entirely through the
42   * I/O streams.  Once you have finished processing the streams, you should
43   * invoke {@link org.apache.commons.net.bsd.RExecClient#disconnect disconnect() }
44   *  to clean up properly.
45   * <p>
46   * The standard output and standard error streams of the
47   * remote process are transmitted over the same connection, readable
48   * from the input stream returned by
49   * {@link org.apache.commons.net.bsd.RExecClient#getInputStream getInputStream() }
50   * <p>
51   * Unlike RExecClient and RCommandClient, it is
52   * not possible to tell the rlogind daemon to return the standard error
53   * stream over a separate connection.
54   * {@link org.apache.commons.net.bsd.RExecClient#getErrorStream getErrorStream() }
55   *  will always return null.
56   * The standard input of the remote process can be written to through
57   * the output stream returned by
58   * {@link org.apache.commons.net.bsd.RExecClient#getOutputStream getOutputSream() }
59   *
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       *
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      * @param localUsername the local user
122      * @param remoteUsername the remote user
123      * @param terminalType the terminal type
124      * @throws IOException on error
125      ***/
126     public void rlogin(String localUsername, String remoteUsername,
127                        String terminalType)
128     throws IOException
129     {
130         rexec(localUsername, remoteUsername, terminalType, false);
131     }
132 
133 }