alaa-alawi

(defun make-upload-filename ()
  (etypecase *upload-filename-generator* 
    ;; the old behaviour.
    (null t)
    ;; the new behaviour.
    ((or symbol function) 
     (lambda (&rest args)
       (let ((filename (apply *upload-filename-generator* args)))
         (when *file-upload-hook*
           (funcall *file-upload-hook* filename))

alaa-alawi

;; original implementation
;; hunchentoot;utils.lisp
;;
(let ((counter 0))
  (declare (ignorable counter))
  (defun make-tmp-file-name (&optional (prefix "hunchentoot"))
    "Generates a unique name for a temporary file. This function is
called from the RFC2388 library when a file is uploaded."
    (let ((tmp-file-name
           #+:allegro