spy_open.c

#define _GNU_SOURCE
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

typedef int (*orig_open_f_type)(const char *pathname, int flags);
typedef int (*orig_open64_f_type)(const char *pathname, int flags);

int open(const char *pathname, int flags){
    orig_open_f_type orig_open;
    orig_open = (orig_open_f_type)dlsym(RTLD_NEXT, "open");
    printf(">>> open(): '%s'!!!\n", pathname);
    return orig_open(pathname, flags);
}
int open64(const char *pathname, int flags){
    orig_open64_f_type orig_open64;
    orig_open64 = (orig_open64_f_type)dlsym(RTLD_NEXT, "open64");
    printf(">>> open64(): '%s'!!!\n", pathname);
    return orig_open64(pathname, flags);
}