(defun copy-whole-line ()
  (interactive)
  (save-excursion
    (kill-new
     (buffer-substring
      (point-at-bol)
      (point-at-eol)))))
(global-set-key  (kbd "C-c w l") 'copy-whole-line)

(defun kill-all-buffers ()
  (interactive)
  (mapc 'kill-buffer (buffer-list)))
(global-set-key (kbd "C-c k k") 'kill-all-buffers)