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 }