Q27296: Example Passing BASIC String Descriptor to Microsoft C

Article: Q27296
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom S_C S_QuickC | mspl13_basic
Last Modified: 6-NOV-1989

The example below demonstrates how to pass a string descriptor from
compiled BASIC to Microsoft C.

This information about inter-language calling applies to QuickBASIC
Versions 4.00, 4.00b, and 4.50 for MS-DOS and to Microsoft BASIC
Compiler Versions 6.00 and 6.00b for MS-DOS and MS OS/2.

For more information about passing other types of parameters between
BASIC and C, and a list of which BASIC and C versions are compatible
with each other, query in the Software/Data Library on the following
word:

   BAS2C

Code Example
------------

REM ===== BASIC PROGRAM =====

DECLARE SUB StringNear CDECL (a$)
CLS
array$ = "This is a test" + CHR$(0)
CALL StringNear(array$)
END

/* ===== C ROUTINE ===== */

#include <stdio.h>
struct struct_string{
     int length;
     char *address;
};

void StringNear(string)
   struct struct_string near *string;
 {
    int i;
    printf("The string is : %s \n\n",string->address);
    printf(" Index       Value       Character\n");
    for (i=0;i < string->length; i++)
       {
       printf("  %2d          %3d            %c\n",i,
              string->address[i], string->address[i]);
       };
 }

===== OUTPUT =====

The string is : This is a test

 Index       Value       Character
   0           84            T
   1          104            h
   2          105            i
   3          115            s
   4           32
   5          105            i
   6          115            s
   7           32
   8           97            a
   9           32
  10          116            t
  11          101            e
  12          115            s
  13          116            t
  14            0