BUG: Windows 95 Access Violation Error After Disabling CTRL+C

• Microsoft Win32 Application Programming Interface (API), included with:
  • Microsoft Windows 95

SYMPTOMS

In a Win32 environment, a console application can be terminated by pressing CTRL+C. To disable CTRL+C input, a console application can call the SetConsoleCtrlHandler(NULL, TRUE) API function.

When this API function is called in Windows NT, CTRL+C is ignored if pressed. However, when it is called in Windows 95, pressing CTRL+C generates an Access Violation error. Similarly, when this API is called in Windows 95, pressing CTRL+BREAK generates an Access Violation error.

RESOLUTION

There are two alternatives when you want to disable CTRL+C and avoid generating an Access Violation error:

1. Install a console control handler to capture and ignore the CTRL+C keypress:




      SetConsoleCtrlHandler(MyHandler, TRUE);
      BOOL MyHandler(DWORD dwEventType)
      {
         if ( dwEvnetType == CTRL_C_EVENT
         if ( dwEventType == CTRL_C_EVENT )
            return TRUE;   // CTRL+C handle by function
         else
            return FALSE;  // pass to next handler
      } 

-or-


2. Disable CTRL+C by disabling the ENABLE_PROCESSED_INPUT console mode. Disabling the ENABLE_PROCESSED_INPUT console mode then reports CTRL+C to the input buffer, not the system:




      SetConsoleMode( hConsoleHandle,
          (Mode & ~ ENABLE_PROCESSED_INPUT) ); 

STATUS

Microsoft has confirmed this to be a bug in the products listed at the beginning of this article.

Additional query words:

Keywords          : kbprg kbConsole kbKernBase kbGrpKernBase 
Version           : winnt:
Platform          : winnt 
Issue type        : kbbug 

Last Reviewed: July 20, 1999