CODEWITHSUNDEEP
emacsbackup
Dan Oblinger
Dan Oblinger

Reputation: 534

Viewing / Reloading emacs backup files

I am successfully using the code below to cause emacs to save many versions of each file. But I cannot figure out what commands you use in emacs to actually load those files into a buffer.

I am expecting some kind of a history viewer command!!! I can find nothing.

(setq backup-directory-alist  '(("." . "~/auto-saves")))
(setq version-control     t
    kept-old-versions   2    kept-new-versions  200
    delete-old-versions t    backup-by-copying  t)

Upvotes: 2

Views: 1419

Answers (2)

jpkotta
jpkotta

Reputation: 9437

You can just open the files in which ever directory you're saving them in (~/autosaves). But the backup-walker package is way better.

Update: I highly recommend using the no-littering package to keep your ~/.emacs.d (and $HOME) clean. Here's my backup config (assuming you have use-package and melpa set up):

(use-package no-littering)

(setq make-backup-files t
      vc-make-backup-files t
      version-control t
      kept-new-versions 128
      kept-old-versions 0
      delete-old-versions t
      backup-by-copying t)

(defun force-backup-of-buffer ()
  (setq buffer-backed-up nil))
(add-hook 'before-save-hook #'force-backup-of-buffer)

(use-package backup-walker)

(let ((dir (no-littering-expand-var-file-name "auto-save/")))
  (make-directory dir t)
  (add-to-list 'auto-save-file-name-transforms `(".*" ,dir t) 'append))

If you don't want to use no-littering, set backup-directory-alist, tramp-persistency-file-name, tramp-backup-directory-alist, and tramp-auto-save-directory.

(setq emacs-persistence-directory 
  (expand-file-name "var" user-emacs-directory))
(let ((dir (expand-file-name "backup" emacs-persistence-directory)))
  (unless (file-directory-p dir)
    (make-directory dir t))
  (setq backup-directory-alist `(("." . ,dir))))

(let ((backup-dir (concat emacs-persistence-directory "tramp-backup/")))
  (setq tramp-persistency-file-name (concat emacs-persistence-directory
                                            "tramp")
        tramp-backup-directory-alist `(("." . ,backup-dir))
        tramp-auto-save-directory (concat emacs-persistence-directory
                                          "tramp-auto-save/"))
  (dolist (d (list tramp-auto-save-directory backup-dir))
    (unless (file-exists-p d)
      (make-directory d t))))

Side note: auto-save is a different feature than backups. Backups save a copy the first time you save a buffer (C-x C-s). Above, I have the function force-backup-of-buffer on before-save-hook to backup on every save. Autosave saves a copy every time you make a certain number of edits. For a given file, there can be many backups, but there's only one autosave.

Upvotes: 3

Dan Oblinger
Dan Oblinger

Reputation: 534

I am leaving jpkotta's answer as the selected one, since backup-walker seems to work for others. For my OSX box, I could not get Backup-Modes to work, and backup walker is more focused on DIFFS rather than just providing access to backup files.

Here is my hacked solution it is a kinda gross, but it works for me. You will need to edit path names for your environment. (see https://www.emacswiki.org/emacs/ForceBackups for the original) I tried, Backup-Modes, and Backup-Directory https://www.emacswiki.org/emacs/BackupDirectory, but this is the first things that kinda worked.)

What this does: - It fixes emacs so it always does an auto-save (surprisingly this is NOT the default) - it adds the command ``M-x history'' to open the backups directory.

Crude, but it works. So sad to see Emacs die!

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;   FORCE-BACKUP-OF-BUFFER
;;;   (See https://www.emacswiki.org/emacs/ForceBackups)

(defun dao-setup-force-backup-of-buffer()
     (setq vc-make-backup-files t)          ; Do backups even for version controlled files!
     (setq version-control t                ; Use version numbers for backups.
      kept-new-versions 10                  ; Number of newest versions to keep.
      kept-old-versions 0                   ; Number of oldest versions to keep.
      delete-old-versions t                 ; Don't ask to delete excess backup versions.
      backup-by-copying t)                  ; Copy all files, don't rename them.
     (add-hook 'before-save-hook  'force-backup-of-buffer)
)

(defun force-backup-of-buffer ()
    ;; Make a special "per session" backup at the first save of each
    ;; emacs session.
    (when (not buffer-backed-up)
      ;; Override the default parameters for per-session backups.
      '(let ((backup-directory-alist  '(("." . "~/emacs-backups")))
            (kept-new-versions 3))
        (backup-buffer)))
      (backup-buffer)
    ;; Make a "per save" backup on each save.  The first save results in
    ;; both a per-session and a per-save backup, to keep the numbering
    ;; of per-save backups consistent.
    (let ((buffer-backed-up nil))
      (backup-buffer)))

(defun history ()
    (interactive)
    (dired-find-file "/User/oblinger/emacs-backups")
)

Upvotes: 0

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