A demonstrate of dynamic executable loading for Linux

hello_dl.c

// gcc -fPIC -shared hello_so.c -o libhello.so
// gcc hello_dl.c -o hello
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>

const char *LIB_SO = "./libhello.so";

int main(void) {

    void *handle = dlopen(LIB_SO, RTLD_LAZY);
    if (!handle) {
      fprintf(stderr, "%s\n", dlerror());
      exit(1);
    }

    dlerror(); // clear error status

    void (*hello)(void);

    hello = dlsym(handle, "hello");

    char *error = dlerror();
    if (error != NULL) {
      fprintf(stderr, "%s\n", error);
      exit(1);
    }

    hello();
    dlclose(handle);

    return 0;
}

hello_so.c

#include <stdio.h>

void hello(void) {

    char buf[100];
    printf("Hello, what is your name?: ");
    scanf("%100s", buf);

    printf("\nHello %s!\n", buf);
}