Q44895: INFO: kbhit() Does Not Take Character out of Buffer

Article: Q44895
Product(s): Microsoft C Compiler
Version(s): 1.0,1.5,2.0,4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbCRT kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600
Last Modified: 26-MAR-2002

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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) 
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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

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