gistfile1.el

(defun kill-buffer-file-name (nondirectory-p)
  (interactive "P")
  (let ((file-name (buffer-file-name)))
    (if (stringp file-name)
        (progn
          (when nondirectory-p
            (setq file-name (file-name-nondirectory file-name)))
          (message "%s" file-name)
          (kill-new file-name))
      (error "This buffer does not visit a file"))))