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 018package org.apache.commons.net.examples.unix; 019 020import java.io.IOException; 021 022import org.apache.commons.net.bsd.RCommandClient; 023import org.apache.commons.net.examples.util.IOUtil; 024 025/** 026 * 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 027 * 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), 028 * passing it to the remote process and writes the process stdout and stderr to local stdout. 029 * <p> 030 * 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. 031 * <p> 032 * Example: java rshell myhost localusername remoteusername "ps -aux" 033 * <p> 034 * Usage: rshell <hostname> <localuser> <remoteuser> <command> 035 */ 036 037// This class requires the IOUtil support class! 038public final class rshell { 039 040 public static void main(final String[] args) { 041 final String server; 042 final String localuser; 043 final String remoteuser; 044 final String command; 045 final RCommandClient client; 046 047 if (args.length != 4) { 048 System.err.println("Usage: rshell <hostname> <localuser> <remoteuser> <command>"); 049 System.exit(1); 050 return; // so compiler can do proper flow control analysis 051 } 052 053 client = new RCommandClient(); 054 055 server = args[0]; 056 localuser = args[1]; 057 remoteuser = args[2]; 058 command = args[3]; 059 060 try { 061 client.connect(server); 062 } catch (final IOException e) { 063 System.err.println("Could not connect to server."); 064 e.printStackTrace(); 065 System.exit(1); 066 } 067 068 try { 069 client.rcommand(localuser, remoteuser, command); 070 } catch (final IOException e) { 071 try { 072 client.disconnect(); 073 } catch (final IOException f) { 074 /* ignored */} 075 e.printStackTrace(); 076 System.err.println("Could not execute command."); 077 System.exit(1); 078 } 079 080 IOUtil.readWrite(client.getInputStream(), client.getOutputStream(), System.in, System.out); 081 082 try { 083 client.disconnect(); 084 } catch (final IOException e) { 085 e.printStackTrace(); 086 System.exit(1); 087 } 088 089 System.exit(0); 090 } 091 092}