001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package examples;
019
020 import java.io.IOException;
021 import org.apache.commons.net.bsd.RCommandClient;
022
023 /***
024 * This is an example program demonstrating how to use the RCommandClient
025 * class. This program connects to an rshell daemon and requests that the
026 * given command be executed on the server. It then reads input from stdin
027 * (this will be line buffered on most systems, so don't expect character
028 * at a time interactivity), passing it to the remote process and writes
029 * the process stdout and stderr to local stdout.
030 * <p>
031 * On Unix systems you will not be able to use the rshell capability
032 * unless the process runs as root since only root can bind port addresses
033 * lower than 1024.
034 * <p>
035 * Example: java rshell myhost localusername remoteusername "ps -aux"
036 * <p>
037 * Usage: rshell <hostname> <localuser> <remoteuser> <command>
038 * <p>
039 ***/
040
041 // This class requires the IOUtil support class!
042 public final class rshell
043 {
044
045 public static final void main(String[] args)
046 {
047 String server, localuser, remoteuser, command;
048 RCommandClient client;
049
050 if (args.length != 4)
051 {
052 System.err.println(
053 "Usage: rshell <hostname> <localuser> <remoteuser> <command>");
054 System.exit(1);
055 return ; // so compiler can do proper flow control analysis
056 }
057
058 client = new RCommandClient();
059
060 server = args[0];
061 localuser = args[1];
062 remoteuser = args[2];
063 command = args[3];
064
065 try
066 {
067 client.connect(server);
068 }
069 catch (IOException e)
070 {
071 System.err.println("Could not connect to server.");
072 e.printStackTrace();
073 System.exit(1);
074 }
075
076 try
077 {
078 client.rcommand(localuser, remoteuser, command);
079 }
080 catch (IOException e)
081 {
082 try
083 {
084 client.disconnect();
085 }
086 catch (IOException f)
087 {}
088 e.printStackTrace();
089 System.err.println("Could not execute command.");
090 System.exit(1);
091 }
092
093
094 IOUtil.readWrite(client.getInputStream(), client.getOutputStream(),
095 System.in, System.out);
096
097 try
098 {
099 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