On 3/15/22 07:47, Jean Louis wrote:
> * hw <hw@adminart.net> [2022-03-15 08:22]:
>> Yes, and how do I make it so that a buffer not visiting a file is
>> being auto-saved without delay once the auto-save-mode has been
>> enabled?  Or can I make it auto-save once before enabling auto-save
>> mode?
> 
> Buffer not visiting file does not know where it should be saved. I am
> using and doing something similar like you, I use buffers without file
> names as additional scratch buffers. If Emacs session is over, those
> temporary buffers are over. And I like sometimes to invoke them in
> different mode, such as `sql-mode' or `emacs-lisp-mode'. Because they
> are not connected to files, they can't be saved so easily.
> 
> (defvar rcd-temp-buffer-mode-history nil)
> (defvar rcd-temp-file-directory "~/tmp/")
> (defvar rcd-temp-buffer-name "RCD TEMPORARY BUFFER")
> (defvar rcd-temp-buffer-modes '(("adoc-mode" . "adoc")
> 				("emacs-lisp-mode" . "el")
> 				("lisp-mode" . ".lisp")
> 				("markdown-mode" . ".md")
> 				("org-mode" . "org")
> 				("sql-mode" . "sql")
> 				("fundamental-mode" . "txt")
> 				("html-mode" . "html")))
> 
> 
> (defun rcd-temp-buffer (&optional name mode)
>    "Generate new temporary buffer."
>    (interactive "p")
>    (let* ((format (concat "*" rcd-temp-buffer-name "%s%s*"))
> 	 (buffer (if name (format format ": " name) (format format "" ""))))
>      (switch-to-buffer (generate-new-buffer buffer))
>      (if current-prefix-arg
> 	(let* ((mode (completing-read
> 		      "Mode: "
> 		      (map-keys rcd-temp-buffer-modes) nil t nil
> 		      'rcd-temp-buffer-mode-history)))
> 	  (funcall (intern mode)))
>        (funcall (intern (or mode "fundamental-mode"))))))
> 
> and that function could be adopted to provide file names for buffers:
> 
> (defun rcd-temp-buffer (&optional name mode)
>    "Generate new temporary buffer."
>    (interactive "p")
>    (let* ((format (concat "*" rcd-temp-buffer-name "%s%s*"))
> 	 (buffer (if name (format format ": " name) (format format "" "")))
> 	 (file-name (concat rcd-temp-file-directory (format-time-string "%Y-%m-%d-%H:%M:%S.txt"))))
>      (switch-to-buffer (generate-new-buffer buffer))
>      (setq buffer-file-name file-name)
>      (if current-prefix-arg
> 	(let* ((mode (completing-read
> 		      "Mode: "
> 		      (map-keys rcd-temp-buffer-modes) nil t nil
> 		      'rcd-temp-buffer-mode-history)))
> 	  (funcall (intern mode)))
>        (funcall (intern (or mode "fundamental-mode"))))))
> 
> Now if I have `do-auto-save' those temporary buffers would be saved I guess.


Thank you very much!

With this, it's not at all necessary to tie the buffers to files. The
do-auto-save function saves "all buffers that need it", and does it
"right now", without delay when called. That's perfect for what I'm
doing.