Static linking with COBOL programs

Let's call the following COBOL module from a C program:

     ---- say.cob ---------------------------
            IDENTIFICATION DIVISION.
            PROGRAM-ID. say.
            ENVIRONMENT DIVISION.
            DATA DIVISION.
            LINKAGE SECTION.
            01 HELLO PIC X(6).
            01 WORLD PIC X(6).
            PROCEDURE DIVISION USING HELLO WORLD.
            DISPLAY HELLO WORLD.
            EXIT PROGRAM.
     ----------------------------------------
     

This program accepts two arguments, displays them, and exit.

From the viewpoint of C, this is equivalent to a function having the following prototype:

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

So, your main program will look like as follows:

     ---- hello.c ---------------------------
     #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 ret;
     }
     ----------------------------------------
     

Compile these programs as follows:

     $ cc -c `cob-config --cflags` hello.c
     $ cobc -c -static say.cob
     $ cobc -o hello hello.o say.o
     $ ./hello
     Hello World!