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    1   /*
    2    * Copyright 2001-2005 The Apache Software Foundation
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *     http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package examples;
    17
    18  import java.io.IOException;
    19  import org.apache.commons.net.bsd.RCommandClient;
    20
    21  /****
    22   * This is an example program demonstrating how to use the RCommandClient
    23   * class. This program connects to an rshell daemon and requests that the
    24   * given command be executed on the server.  It then reads input from stdin
    25   * (this will be line buffered on most systems, so don't expect character
    26   * at a time interactivity), passing it to the remote process and writes
    27   * the process stdout and stderr to local stdout.
    28   * <p>
    29   * On Unix systems you will not be able to use the rshell capability
    30   * unless the process runs as root since only root can bind port addresses
    31   * lower than 1024.
    32   * <p>
    33   * Example: java rshell myhost localusername remoteusername "ps -aux"
    34   * <p>
    35   * Usage: rshell <hostname> <localuser> <remoteuser> <command>
    36   * <p>
    37   ***/
    38
    39  // This class requires the IOUtil support class!
    40  public final class rshell
    41  {
    42
    43      public static final void main(String[] args)
    44      {
    45          String server, localuser, remoteuser, command;
    46          RCommandClient client;
    47
    48          if (args.length != 4)
    49          {
    50              System.err.println(
    51                  "Usage: rshell <hostname> <localuser> <remoteuser> <command>");
    52              System.exit(1);
    53              return ; // so compiler can do proper flow control analysis
    54          }
    55
    56          client = new RCommandClient();
    57
    58          server = args[0];
    59          localuser = args[1];
    60          remoteuser = args[2];
    61          command = args[3];
    62
    63          try
    64          {
    65              client.connect(server);
    66          }
    67          catch (IOException e)
    68          {
    69              System.err.println("Could not connect to server.");
    70              e.printStackTrace();
    71              System.exit(1);
    72          }
    73
    74          try
    75          {
    76              client.rcommand(localuser, remoteuser, command);
    77          }
    78          catch (IOException e)
    79          {
    80              try
    81              {
    82                  client.disconnect();
    83              }
    84              catch (IOException f)
    85              {}
    86              e.printStackTrace();
    87              System.err.println("Could not execute command.");
    88              System.exit(1);
    89          }
    90
    91
    92          IOUtil.readWrite(client.getInputStream(), client.getOutputStream(),
    93                           System.in, System.out);
    94
    95          try
    96          {
    97              client.disconnect();
    98          }
    99          catch (IOException e)
    100         {
    101             e.printStackTrace();
    102             System.exit(1);
    103         }
    104
    105         System.exit(0);
    106     }
    107
    108 }
    109