wrap_open.c

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

int (*_open)(const char *name, int flags, ...);
int (*_open64)(const char *name, int flags, ...);

void __attribute__ ((constructor)) setup(void) {
    _open = (int (*)(const char * pathname, int flags,...)) dlsym(RTLD_NEXT, "open");
    _open64 = (int (*)(const char * pathname, int flags,...)) dlsym(RTLD_NEXT, "open64");
}

int open(const char * pathname, int flags,int perms)
{
    return _open(pathname, flags,perms);
}

int open64(const char * pathname, int flags, int perms)
{
    return _open64(pathname, flags,perms);
}