(when (string? FD) (setf FD (open FD "r")))
(let ((D (list (context) nil LENGTH 0 0 FD OFFSET)))
(when (< LENGTH) (setf (D 2) (lseek FD 0 SEEK_END)))
(when (string? FD) (setf FD (open FD "r")))
(let ((D (list (context) nil LENGTH 0 0 FD OFFSET)))
(when (< LENGTH) (setf (D 2) (lseek FD 0 SEEK_END)))