build.sh

gcc dlopen_test.c -ldl

main.c

#include <stdlib.h>
#include <stdio.h>
#include <dlfcn.h>

int main (void) {
  while(1) {
    system("gcc -c -fPIC numberwang.c -o numberwang.o");
    system("gcc numberwang.o -shared -o numberwang.so");
    int (*numberwang)(void);
    void *handle = dlopen("./numberwang.so", RTLD_NOW);
    numberwang = dlsym(handle, "numberwang");
    printf("numberwang: %d!\n", (*numberwang)());
    dlclose(handle);
    getchar();
  }
}

numberwang.c

int numberwang (void) {
  return 6;
}