main.c

程序代码使用说明： (1)所有源代码目录下都提供了Makefile（非Qt）

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

int main()
{
    fprintf(stdout, "Press Enter key to load library... \n");
    getchar();
    
    // open the library
    fprintf(stdout, "Loading library libprint.so... \n");
    void* handle = dlopen("./libprint.so", RTLD_LAZY);
    if (!handle) {
        fprintf(stderr, "Failed to open library: %s \n", dlerror());
        exit(-1);
    }
     
    // load the symbol
    fprintf(stdout, "Loading symbol print_foo()... \n");
    typedef void (*print_t) ();
    dlerror();  // reset error
    print_t pfoo = (print_t)dlsym(handle, "print_foo");
    const char* dlsym_error = dlerror();
    if (dlsym_error) {
        fprintf(stderr, "Failed to load symbol: %s \n", dlsym_error);
        dlclose(handle);
        exit(-1);
    }

    fprintf(stdout, "Calling print_foo()... \n");
    pfoo();

    fprintf(stdout, "Closing library... \n");
    dlclose(handle);
    
    return 0;
}