init-keybindings.el

(defun copy-buffer-file-name ()
  "Puts the file name of the current buffer (or the current directory,
if the buffer isn't visiting a file) onto the kill ring, so that
it can be retrieved with \\[yank], or by another program."
  (interactive)
  (let ((fn (or
             (buffer-file-name (current-buffer))
             ;; Perhaps the buffer isn't visiting a file at all.  In
             ;; that case, let's return the directory.
             (expand-file-name default-directory))))
    (when (null fn)
      (error "Buffer doesn't appear to be associated with any file or directory."))
    (kill-new fn)
    (message "%s" fn)
    fn))


(global-set-key (kbd "C-/") 'copy-buffer-file-name)
(global-set-key (kbd "<f8>") 'copy-buffer-file-name)