Cobol interface with C

Question

So, i'm work with C and OpenCobol, and, I whant to know if have an way to get the value of a internal cobol source...

for example (based on sample of this link): http://www.opencobol.org/modules/bwiki/index.php?cmd=read&page=UserManual%2F2_3

---- say.cob ---------------------------
      IDENTIFICATION DIVISION.
      PROGRAM-ID. say.

      ENVIRONMENT DIVISION.
      DATA DIVISION.

      WORKING-STORAGE SECTION.
      01 TESTE PIC 9(9) VALUE ZEROS.

      LINKAGE SECTION.
      01 HELLO PIC X(6).
      01 WORLD PIC X(6).

      PROCEDURE DIVISION USING HELLO WORLD.
          MOVE 456 TO TESTE.
          DISPLAY TESTE.
          DISPLAY HELLO WORLD.

         *> RETURN TESTE. ??????

          EXIT PROGRAM.
----------------------------------------

And, the C code when I use is that:

---- hello.c ---------------------------

#include <stdio.h>
#include <libcob.h>

extern int say(char *hello, char *world);

int
main()
{
  int ret;
  char hello[6] = "Hello ";
  char world[6] = "World!";

  cob_init(0, NULL);

  ret = say(hello, world); // return the 000000456 ?????????? 
  // How to make this :(

  return ret;
}
----------------------------------------

Or, have an whay to get the cobol variable, something like this:

// ... code ...
int value = cob_getvar(TESTE);
// ... code ...

Answer 1

Look at page 7-7 of the OpenCOBOL Programmers Guide. For the data that you want to pass back to your C program, add another argument and pass it by reference to the COBOL program. Declare your TESTE as binary to match the C declaration. You can also pass back the automatically-defined RETURN-CODE, if you like. So your COBOL would be something like this:

  DATA DIVISION.
  LINKAGE SECTION.
  01 HELLO PIC X(6).
  01 WORLD PIC X(6).
  01 TESTE PIC S9(9) USAGE BINARY-LONG.
  PROCEDURE DIVISION USING 
      BY VALUE HELLO
      BY VALUE WORLD
      BY REFERENCE TESTE.
  0000-MAIN-ROUTINE.
      MOVE 456 TO TESTE
      MOVE 1 TO RETURN-CODE
      GOBACK.

And in your calling program:

int teste;
int returnCode;
char hello[6] = "Hello ";
char world[6] = "World!";

cob_init(0, NULL);
returnCode = say(hello, world, &teste);