Emacs: Auto Save

By Xah Lee. Date: . Last updated: .

Real Auto Save File

This is the best solution i use since about 2017. Most simple code, reliable, and practical.

Save all files when you switch out of emacs.

Put this in emacs init.

(defun xah-save-all-unsaved ()
  "Save all unsaved files. no ask.
Version 2019-11-05"
  (save-some-buffers t ))

(if (version< emacs-version "27")
    (add-hook 'focus-out-hook 'xah-save-all-unsaved)
  (setq after-focus-change-function 'xah-save-all-unsaved))

disable emacs's “#auto-save#” backup

;; stop creating those #auto-save# files
(setq auto-save-default nil)

emacs has auto-save-mode, however, it's not what you think.

Emacs's auto-save-mode periodically saves a copy of your file with the name #filename#.

When you save the file, those #files# are deleted automatically.

In case of crash or electricity outage, when you open a file afterward, emacs will detect those #files# and ask if you want to recover.

But the problem is, even if no crash, in lots of situations (such as sync to server), you'll find those #files# annoying, because they are often symbolic links to non-existent files, and will cause tools like rsync to complain or choke some dir walk scripts.

See also: Emacs: Turn Off Backup

stop emacs from creating .#lock file links

emacs backup problem 2018-10-12 58cc4
emacs lock file problem 2018-10-12

emacs backup is so annoying. even when you have it off (setq auto-save-default nil) , it still creates temp # files. which crashes script that traverse dir.


(setq create-lockfiles nil)

This will completely stop emacs from creating temoporary symbolic link file named “#something”.

(disable lock file may be a problem if you have situations where a file is being edited by different people or instances of emacs.)

2018-10-12 thanks to Dale Hagglund [ https://twitter.com/DaleHagglund/status/1050786629844004865 accessed: 2018-10-12] for create-lockfiles

alternative solution and problem

You can set emacs to auto save files directly, instead of creating those #filename#.

Put the following in your emacs init:

(setq auto-save-default t)
(setq auto-save-visited-file-name t)


However, this does not work well. Emacs still generates those #files#, this time, named like this:

.#xxtemp.201601134145.44920.el -&amp;gt; xah@xah-p6813w.21261:1452244010

If you have scripts going thru your machine, you get this error:

error: cannot open /home/john/web/.#vocabulary.html No such file or directory

(info "(elisp) Auto-Saving")

There are probably ways to fix this, with hooks or timer, but i haven't looked into.

thanks to Fuqiao Xue (xfq) [https://github.com/xfq/] and finalpatch [http://www.weibo.com/u/1885517634]

thanks to http://irreal.org/blog/?p=4867, Anna Pawlicka (@AnnaPawlicka)

If you have a question, put $5 at patreon and message me on xah discord.
Or support me by Buy Xah Emacs Tutorial

Emacs Tutorial

Emacs Init

Emacs Keys


ELisp Examples

ELisp Write Major Mode

Emacs Init

Init Basics


text editing