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