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.unix;
19
20 import java.io.IOException;
21 import org.apache.commons.net.bsd.RCommandClient;
22
23 import examples.util.IOUtil;
24
25 /***
26 * This is an example program demonstrating how to use the RCommandClient
27 * class. This program connects to an rshell daemon and requests that the
28 * given command be executed on the server. It then reads input from stdin
29 * (this will be line buffered on most systems, so don't expect character
30 * at a time interactivity), passing it to the remote process and writes
31 * the process stdout and stderr to local stdout.
32 * <p>
33 * On Unix systems you will not be able to use the rshell capability
34 * unless the process runs as root since only root can bind port addresses
35 * lower than 1024.
36 * <p>
37 * Example: java rshell myhost localusername remoteusername "ps -aux"
38 * <p>
39 * Usage: rshell <hostname> <localuser> <remoteuser> <command>
40 * <p>
41 ***/
42
43 // This class requires the IOUtil support class!
44 public final class rshell
45 {
46
47 public static void main(String[] args)
48 {
49 String server, localuser, remoteuser, command;
50 RCommandClient client;
51
52 if (args.length != 4)
53 {
54 System.err.println(
55 "Usage: rshell <hostname> <localuser> <remoteuser> <command>");
56 System.exit(1);
57 return ; // so compiler can do proper flow control analysis
58 }
59
60 client = new RCommandClient();
61
62 server = args[0];
63 localuser = args[1];
64 remoteuser = args[2];
65 command = args[3];
66
67 try
68 {
69 client.connect(server);
70 }
71 catch (IOException e)
72 {
73 System.err.println("Could not connect to server.");
74 e.printStackTrace();
75 System.exit(1);
76 }
77
78 try
79 {
80 client.rcommand(localuser, remoteuser, command);
81 }
82 catch (IOException e)
83 {
84 try
85 {
86 client.disconnect();
87 }
88 catch (IOException f)
89 {}
90 e.printStackTrace();
91 System.err.println("Could not execute command.");
92 System.exit(1);
93 }
94
95
96 IOUtil.readWrite(client.getInputStream(), client.getOutputStream(),
97 System.in, System.out);
98
99 try
100 {
101 client.disconnect();
102 }
103 catch (IOException e)
104 {
105 e.printStackTrace();
106 System.exit(1);
107 }
108
109 System.exit(0);
110 }
111
112 }
113