as-MacBook-Air:.emacs.d a$ ls -la
total 24
drwx------  11 a  staff   374 Dec 18 12:20 .
drwxr-xr-x+ 34 a  staff  1156 Dec 18 12:20 ..
-rw-r--r--   1 a  staff   195 Dec 18 12:20 .smex-items
drwx------   3 a  staff   102 Dec 12 21:04 auto-save-list
drwxr-xr-x  21 a  staff   714 Dec 18 12:20 backups
drwxrwxrwx   2 a  admin    68 Dec 18 12:08 cache
drwxr-xr-x  23 a  staff   782 Dec 18 08:51 elpa
drwx------   4 a  staff   136 Dec 18 08:23 eshell
-rw-r--r--   1 a  staff   195 Dec 18 12:20 places
-rw-r--r--   1 a  staff  1505 Dec 18 12:20 tramp
drwxr-xr-x   4 a  staff   136 Dec 18 09:19 url

(defun ido-kill-emacs-hook () (ignore-errors (ido-save-history)))