Article: Q45563
Product(s): Microsoft C Compiler
Version(s): winnt:
Operating System(s):
Keyword(s): kb16bitonly
Last Modified: 22-JUL-2001
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The information in this article applies to:
- The C Run-Time (CRT), included with:
- Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, 6.0ax
- Microsoft C for OS/2, versions 5.1, 6.0, 6.0a
- Microsoft C/C++ for MS-DOS, version 7.0
- Microsoft Visual C++, versions 1.0, 1.5
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SUMMARY
=======
The getchar() function will wait for a carriage return even if setbuf() is used
to unbuffer stdin.
MORE INFORMATION
================
The function setbuf() affects a stream file buffer, such as stdin, but has no
effect on the keyboard or MS-DOS device buffers. The stream I/O function
getchar() can read a character from the keyboard buffer only when the keyboard
buffer is flushed by either being filled, by a carriage return, or by an
interrupt 0x21, function 0xC call.
To read normal characters directly from the keyboard, you can use the console I/O
function getch(). To read control codes such as ALT+Q (echo subsequent output to
printer) or ALT+R (pause output), you can use the _bios_keybrd() function. For
more information on this function, query on the following word in the Microsoft
Knowledge Base:
_bios_keybrd()
The following example demonstrates the difference between using getchar() and
getch().
Sample Code
-----------
/* Compile options needed: none
*/
#include <stdio.h>
#include <conio.h>
void main (void)
{
setbuf (stdin, NULL); /* cause stdin to be unbuffered */
if (getchar () != EOF )
printf ("getchar() still waits for return key\n");
if (getch () != EOF )
printf ("getch() does not wait for return key\n");
}
Additional query words: kbinf 1.00 1.50 5.10 6.00 6.00a 6.00ax 7.00
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Keywords : kb16bitonly
Technology : kbVCsearch kbAudDeveloper kbCRT
Version : winnt:
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