Article: Q57888
Product(s): Microsoft C Compiler
Version(s): MS-DOS:5.1,6.0,6.00a,6.00ax,7.0; WINDOWS:1.0,1.5; WINDOWS NT:1.0,2.0,2.1,4.0,5.0
Operating System(s):
Keyword(s): kbcode kbCRT kbVC100 kbVC150 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600
Last Modified: 25-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/C++ for MS-DOS, version 7.0
- Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5
- Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 2.1, 4.0, 5.0, 6.0
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SUMMARY
=======
In Microsoft C, when reading extended characters you must make two calls to
getch() because the first call returns a value indicating that the key is an
extended character. The second call returns the actual key code.
MORE INFORMATION
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When you are reading an extended character, the first return value will be
either 0xE0 or 0x00, depending on which extended key is pressed.
Sample Code
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#include <stdio.h>
#include <conio.h>
void main(void)
{
int ch, scan;
do {
ch = getch(); /* 1st getch() gets ASCII code */
printf("Character is %d\n", ch);
if (ch == 0x00 || ch == 0XE0) { /* if extended key */
scan = getch(); /* 2nd getch() gets "scan code" */
printf("\tExtended character: scan is %d\n", scan);
}
} while (ch != 27); /* exit loop on ESC */
}
For a discussion of keystrokes and scan codes, refer to "The New Peter Norton
Programmer's Guide to the IBM PC & PS/2," by Peter Norton and Richard
Wilton.
Additional query words:
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Keywords : kbcode kbCRT kbVC100 kbVC150 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600
Technology : kbVCsearch kbAudDeveloper kbCRT
Version : MS-DOS:5.1,6.0,6.00a,6.00ax,7.0; WINDOWS:1.0,1.5; WINDOWS NT:1.0,2.0,2.1,4.0,5.0
Issue type : kbinfo
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