Variable: make-backup-file-name-function

make-backup-file-name-function is a customizable variable defined in files.el.gz.

Value

make-backup-file-name--default-function

Documentation

A function that make-backup-file-name uses to create backup file names.

The function receives a single argument, the original file name.

If you change this, you may need to change backup-file-name-p and file-name-sans-versions too.

You could make this buffer-local to do something special for specific files.

For historical reasons, a value of nil means to use the default function. This should not be relied upon.

See also backup-directory-alist.

This variable was added, or its default value changed, in Emacs 24.4.

View in manual

Probably introduced at or before Emacs version 21.1.

Source Code

;; Defined in /usr/src/emacs/lisp/files.el.gz
(defcustom make-backup-file-name-function
  #'make-backup-file-name--default-function
  "A function that `make-backup-file-name' uses to create backup file names.
The function receives a single argument, the original file name.

If you change this, you may need to change `backup-file-name-p' and
`file-name-sans-versions' too.

You could make this buffer-local to do something special for specific files.

For historical reasons, a value of nil means to use the default function.
This should not be relied upon.

See also `backup-directory-alist'."
  :version "24.4"     ; nil -> make-backup-file-name--default-function
  :group 'backup
  :type '(choice (const :tag "Deprecated way to get the default function" nil)
		 (function :tag "Function")))