How do?

gistfile1.c

#include <stdio.h>
#include <krb5.h>
/*
  In krb5.h ...
    krb5_error_code is defined as:
      typedef int krb5_int32
      typedef krb5_int32 krb5_error_code;
  krb5_context is defined as:
      struct _krb5_context;
      typedef struct _krb5_context * krb5_context;
  krb5_init_context is defined as:
      krb5_error_code krb5_init_context(krb5_context *context);
 */

int main() {
    krb5_context kcontext = NULL;
    krb5_error_code code;

    code = krb5_init_context(&kcontext);
    if (code == 0) {
        /* Do something w/ kcontext, usually passing it as a handle
           into other k5b5 functions. */
        printf("Code: %d\n");
    }
    if (kcontext != NULL) {
        krb5_free_context(kcontext);
    }
}

/*
  The actual implementation of krb5_context isn't included in the
  header files. It's used as an opaque data type. How can I construct
  one, initialize it to NULL, and pass it by reference to a
  krb5_init_context via ffi.
*/