HANDLER.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples.  
*       Copyright 1993 - 1998 Microsoft Corporation. 
*       All rights reserved.  
*       This source code is only intended as a supplement to  
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the  
*       Microsoft samples programs. 
\******************************************************************************/ 
 
#include <windows.h> 
#include <string.h> 
#include "console.h" 
 
HANDLE hConsole; /* current console output handle */ 
 
/******************************************************************* 
* FUNCTION: handler_routine(DWORD dwCtrlType)                      * 
*                                                                  * 
* PURPOSE: this is the control handler routine activated by ctrl+c * 
*          or ctrl+break keys                                      * 
*                                                                  * 
* INPUT: the type of control event                                 * 
*******************************************************************/ 
 
BOOL WINAPI handler_routine(DWORD dwCtrlType) 
{ 
  CHAR szTemp[64]; 
 
  /* print out what control event was received to the current console */ 
  switch(dwCtrlType) 
    { 
    case CTRL_C_EVENT: 
      strcpy(szTemp, "CTRL_C_EVENT"); 
      break; 
    case CTRL_BREAK_EVENT: 
      strcpy(szTemp, "CTRL_BREAK_EVENT"); 
      break; 
    case CTRL_CLOSE_EVENT: 
      strcpy(szTemp, "CTRL_CLOSE_EVENT"); 
      break; 
    case CTRL_LOGOFF_EVENT: 
      strcpy(szTemp, "CTRL_LOGOFF_EVENT"); 
      break; 
    case CTRL_SHUTDOWN_EVENT: 
      strcpy(szTemp, "CTRL_SHUTDOWN_EVENT"); 
      break; 
    default: 
      strcpy(szTemp, "unknown event"); 
      break; 
    } 
  strcat(szTemp, " detected"); 
  myPuts(hConsole, szTemp); 
  return(TRUE); 
} 
 
 
/********************************************************************* 
* FUNCTION: demoSetCtrlHandler(HANDLE hConOut)                       * 
*                                                                    * 
* PURPOSE: demonstrate SetConsoleCtrlHandler by setting a ctrl+break * 
*          and ctrl+c handler. When the user hits either one of      * 
*          these keys, a message is printed to the console           * 
*          indicating the event.                                     * 
*                                                                    * 
* INPUT: the output handle to write to                               * 
*********************************************************************/ 
 
void demoSetCtrlHandler(HANDLE hConOut) 
{ 
  BOOL bSuccess; 
 
  setConTitle(__FILE__); 
  hConsole = hConOut; /* set global console output handle for handler */ 
  myPuts(hConOut, "Let's install a ctrl+c and ctrl+break handler for this\n" 
                  "process. Hit ctrl+c and ctrl+break a few times to test\n" 
                  "the handler. Hit enter to return..."); 
  /* set handler for this process */ 
  bSuccess = SetConsoleCtrlHandler(handler_routine, TRUE); 
  PERR(bSuccess, "SetConsoleCtrlHandler"); 
  /* wait for user to hit enter */ 
  while (myGetchar() != 0xd) 
    ; 
  /* now let's generate some control events */ 
  myPuts(hConOut, "Now we'll use GenerateConsoleCtrlEvent to generate a\n" 
                  "ctrl+c and a ctrl+break event...\n"); 
  bSuccess = GenerateConsoleCtrlEvent(CTRL_C_EVENT, 0); 
  PERR(bSuccess, "GenerateConsoleCtrlEvent"); 
  bSuccess = GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, 0); 
  PERR(bSuccess, "GenerateConsoleCtrlEvent"); 
  Sleep(1000); /* give ctrl handle time to output messages */ 
  myPuts(hConOut, "\nNow choose 'Close' then 'Cancel' from the system\n" 
                  "menu of this console and note that we receive a\n" 
                  "CTRL_CLOSE_EVENT...\n"); 
  myPuts(hConOut, "\nHit enter to continue..."); 
  myGetchar(); 
  /* remove our handler from the list of handlers */ 
  bSuccess = SetConsoleCtrlHandler(handler_routine, FALSE); 
  PERR(bSuccess, "SetConsoleCtrlHandler"); 
  return; 
}