int para_mmap(size_t length, int prot, int flags, int fd, void *map);
int para_open(const char *path, int flags, mode_t mode);
int para_mkdir(const char *path, mode_t mode);
-int para_chdir(const char *path);
int mmap_full_file(const char *filename, int open_mode, void **map,
size_t *size, int *fd_ptr);
int para_munmap(void *start, size_t length);