Creating a module system (dynamic loading) in C

Question

How would one go about loading compiled C code at run time, and then calling functions within it? Not like simply calling exec().

EDIT: The the program loading the module is in C.

Answer 1

In Linux/UNIX you can use the POSIX dlopen / dlsym / dlerror / dlclose functions to dynamically open shared libraries and access the symbols (including functions) they provide, see the man page for details.