emacs auto backup

(setq backup-directory-alist ‘((”” . “~/backup/emacs/backup”)))

(setq-default make-backup-file t)

(setq make-backup-file t)

(setq make-backup-files t)

(setq version-control t)

(setq kept-old-versions 2)

(setq kept-new-versions 10)

(setq delete-old-versions t)