#ifndef S_ISDIR
# define S_ISDIR(m) ((m & S_IFMT) == S_IFDIR)
#endif /* not S_ISDIR */
#ifndef F_OK
# define F_OK 0
#endif /* not F_OK */
#ifndef X_OK
# define X_OK 1
#endif /* not X_OK */
#ifndef W_OK
# define W_OK 2
#endif /* not W_OK */
