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 examples;
19
20 import java.io.IOException;
21 import org.apache.commons.net.bsd.RCommandClient;
22
23 /***
24 * This is an example program demonstrating how to use the RCommandClient
25 * class. This program connects to an rshell daemon and requests that the
26 * given command be executed on the server. It then reads input from stdin
27 * (this will be line buffered on most systems, so don't expect character
28 * at a time interactivity), passing it to the remote process and writes
29 * the process stdout and stderr to local stdout.
30 * <p>
31 * On Unix systems you will not be able to use the rshell capability
32 * unless the process runs as root since only root can bind port addresses
33 * lower than 1024.
34 * <p>
35 * Example: java rshell myhost localusername remoteusername "ps -aux"
36 * <p>
37 * Usage: rshell <hostname> <localuser> <remoteuser> <command>
38 * <p>
39 ***/
40
41 // This class requires the IOUtil support class!
42 public final class rshell
43 {
44
45 public static final void main(String[] args)
46 {
47 String server, localuser, remoteuser, command;
48 RCommandClient client;
49
50 if (args.length != 4)
51 {
52 System.err.println(
53 "Usage: rshell <hostname> <localuser> <remoteuser> <command>");
54 System.exit(1);
55 return ; // so compiler can do proper flow control analysis
56 }
57
58 client = new RCommandClient();
59
60 server = args[0];
61 localuser = args[1];
62 remoteuser = args[2];
63 command = args[3];
64
65 try
66 {
67 client.connect(server);
68 }
69 catch (IOException e)
70 {
71 System.err.println("Could not connect to server.");
72 e.printStackTrace();
73 System.exit(1);
74 }
75
76 try
77 {
78 client.rcommand(localuser, remoteuser, command);
79 }
80 catch (IOException e)
81 {
82 try
83 {
84 client.disconnect();
85 }
86 catch (IOException f)
87 {}
88 e.printStackTrace();
89 System.err.println("Could not execute command.");
90 System.exit(1);
91 }
92
93
94 IOUtil.readWrite(client.getInputStream(), client.getOutputStream(),
95 System.in, System.out);
96
97 try
98 {
99 client.disconnect();
100 }
101 catch (IOException e)
102 {
103 e.printStackTrace();
104 System.exit(1);
105 }
106
107 System.exit(0);
108 }
109
110 }
111