Q27323: Passing BASIC 2-Dimensional Variable-Length String Array to C

Article: Q27323
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 following example demonstrates how to pass a two-dimensional array
of variable-length strings 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 TwoStringArray CDECL (_
            BYVAL p1o AS INTEGER,_
            BYVAL p1s AS INTEGER)
CLS
DIM array$(4, 4)
FOR i = 0 TO 4
 FOR j = 0 TO 4
   array$(i, j) = STRING$(5, 65 + (i + j)) + CHR$(0)
 NEXT j
NEXT i
CALL TwoStringArray(VARPTR(array$(0, 0)), VARSEG(array$(0, 0)))
END

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

#include <stdio.h>
struct struct_string{
     int length;
     char *address;
     };
struct string_array{
     struct struct_string x[5][5];
};

void TwoStringArray(array)
   struct string_array far *array;
 {
    int i,j;
    for (i=0;i < 5; i++)
       {
         for(j=0;j<5;j++)
         {
             printf("  %s  ",array->x[i][j].address);
         };
         printf("\n");
       };
 }

===== OUTPUT =====

  AAAAA    BBBBB    CCCCC    DDDDD    EEEEE
  BBBBB    CCCCC    DDDDD    EEEEE    FFFFF
  CCCCC    DDDDD    EEEEE    FFFFF    GGGGG
  DDDDD    EEEEE    FFFFF    GGGGG    HHHHH
  EEEEE    FFFFF    GGGGG    HHHHH    IIIII