DOCUMENT:Q44895  26-MAR-2002  [visualc]
TITLE   :INFO: kbhit() Does Not Take Character out of Buffer
PRODUCT :Microsoft C Compiler
PROD/VER::1.0,1.5,2.0,4.0,5.0,6.0
OPER/SYS:
KEYWORDS:kbcode kbCRT kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600

======================================================================

-------------------------------------------------------------------------------
The information in this article applies to:

 - The C Run-Time (CRT), included with:
    - Microsoft C for MS-DOS 
    - Microsoft C for OS/2 
    - Microsoft C/C++ for MS-DOS 
    - Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5 
    - Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 4.0, 5.0, 6.0 
    - Microsoft Visual C++.NET (2002) 
-------------------------------------------------------------------------------

NOTE: Microsoft Visual C++ NET (2002) supported both the managed code model that is provided by the .NET Framework and the unmanaged native Windows code model. The information in this article applies to unmanaged Visual C++ code only.

SUMMARY
=======

When an application tests the value returned by the kbhit() function, the
application must explicitly remove the character from the keyboard buffer after
entering the keystroke. Otherwise, kbhit() continues to return TRUE.

The following code example demonstrates the situation:

Sample Code
-----------

   /*
    * Compiler options needed: None
    */ 

   #include <conio.h>

   void main(void)
   {
      while (!kbhit())
         ;          // Waits for keystroke
      while (kbhit())
         getch();   // Empties buffer
      while (!kbhit())
         ;          // Waits for keystroke
   }

Additional query words:

======================================================================
Keywords          : kbcode kbCRT kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 
Technology        : kbVCsearch kbAudDeveloper kbCRT
Version           : :1.0,1.5,2.0,4.0,5.0,6.0
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2002.