#include <errno.h>
    #include <dlfcn.h>
    #include <stdio.h>
    #include <strings.h>
    #include <string.h>
    #include <sys/_timespec.h>
    #include <sys/stat.h>
    #include <sys/mount.h>

    #ifndef RTLD_NEXT
    #define RTLD_NEXT   ((void *) -1l)
    #endif

    int (*getdirentries_orig)(int fd, char *buf, int nbytes, long *basep);
    int (*lstat_orig)(const char *path, struct stat *sb);
    int (*fstatfs_orig)(int fd, struct statfs *buf);
    int (*chmod_orig)(const char *path, mode_t mode);

    #define HOOK(func) func##_##orig = dlsym(RTLD_NEXT,#func)

    int getdirentries(int fd, char *buf, int nbytes, long *basep) {
        HOOK(getdirentries);
        printf("getdirentriesn");
        return getdirentries_orig(fd, buf, nbytes, basep);
    }

    int lstat(const char *path, struct stat *sb) {
        HOOK(lstat);
        printf("lstatn");
        return (lstat_orig(path, sb));
    }

    int fstatfs(int fd, struct statfs *buf) {
        HOOK(fstatfs);
        printf("fstatfsn");
        return fstatfs_orig(fd, buf);
    }

    int chmod(const char *path, mode_t mode) {
        HOOK(chmod);
        printf("chmodn");
        return chmod_orig(path, mode);
    }

cc -Wall -g -O2 -fPIC -shared -o preload.so preload.c