You do get slightly more with WEXITSTATUS(status) after you've done a waitpid(pid, &status, ...) but this was never meant as a facility for anything more than very small integers.

I I understand ramen_noodle's hint correctly, you would have a function pointer "funion" which you run in the child, and which returns its result in the memory location pointed to by anarg.

What are you trying to achieve; why is regular IPC out of the question?