I set an explicit file to customization created via the UI. It's named custom.el. Currently, I use the followed snippets to create this file if not exist.
(defconst custom-file (expand-file-name "custom.el" user-emacs-directory))
(unless (file-exists-p custom-file)
(shell-command (concat "touch " custom-file)))
There is an ugly shell-command touch in, any other elisp functions can do this?
You can use (write-region "" nil custom-file) not sure that is the ideal solution.
来源：https://stackoverflow.com/questions/14071991/how-to-create-an-empty-file-by-elisp