Shutting down a machine across the network

Problem/Question/Abstract:

How to send a shutdown command in a network?

Answer:

{-----------------------------------------------------------------------------
Unit Name:     formClient
Author:        Stewart Moss

Creation Date: 27 February, 2002 (16:30)
Documentation Date: 27 February, 2002 (16:30)

Version 1.0
-----------------------------------------------------------------------------

Description:

  This is to demonstrate shutting down a machine over the network.

  ** Tobias R. requests the article "How to send a shutdown command in a network?" **

  This is not really what you want. I think you are looking for some kind
  of IPC or RPC command. But this will work. Each machine needs to run
  a copy of this server.

  It uses the standard delphi ServerSocket found in the "ScktComp" unit.

  Create a form (name frmClient) with a TServerSocket on it (name ServerSocket)
  set the Port property of ServerSocket to 5555. Add a TMemo called Memo1.

  It listens on port 5555 using TCP/IP.

  It has a very simple protocol.
  Z = Show message with "Z"
  B = Beep
  S = Shutdown windows

  Run the program.. Then from the command prompt type in
  "telnet localhost 5555". Type in one of the three commands above
  (all in uppercase) and the server will respond.

Copyright 2002 by Stewart Moss. All rights reserved.
-----------------------------------------------------------------------------}

unit formClient;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ScktComp, StdCtrls;

type
  TfrmClient = class(TForm)
    ServerSocket: TServerSocket;
    Memo1: TMemo;
    procedure ServerSocketClientRead(Sender: TObject;
      Socket: TCustomWinSocket);
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmClient: TfrmClient;

implementation

{$R *.DFM}

procedure TfrmClient.ServerSocketClientRead(Sender: TObject;
  Socket: TCustomWinSocket);
var
  Incomming: string;
begin
  // read off the socket
  Incomming := Socket.ReceiveText;

  memo1.Lines.Add(incomming);

  if Incomming = 'S' then // Shutdown Protocol
    ExitWindowsEx(EWX_FORCE or EWX_SHUTDOWN, 0);

  if Incomming = 'B' then // Beep Protocol
    Beep;

  if Incomming = 'Z' then // Z protocol
    showmessage('Z');
end;

procedure TfrmClient.FormCreate(Sender: TObject);
begin
  ServerSocket.Active := true;
end;

procedure TfrmClient.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  ServerSocket.Active := false;
end;

end.