Re: Set major mode for all visited files by extension

[Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Tim Johnson wrote:

> With my configuration, when I open emacs and load
> a session, it appears that a modified
> auto-mode-alist entry is consulted *after* the
> associated major-mode from the previous session
> [...]

Yeah? This is stored somewhere? I don't like that...

> A practical application is if I have been using the
> built-in elisp mode for .el files and then implement
> xah-elisp-mode, even if I code
>
> (add-to-list 'auto-mode-alist '("\\.el$" . xah-elisp-mode))

You keep track of what's already there? Maybe it's
the first hit that gets executed. But I suppose one
don't tell that .el files should be
`emacs-lisp-mode'. What mode do they turn up in?
If you just create a test.el, I mean?

I do this, it is more clear IMO:

;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;;   http://user.it.uu.se/~embe8573/emacs-init/mode-by-filename.el
;;;   https://dataswamp.org/~incal/emacs-init/mode-by-filename.el

(let ((modes (list
     '("\\.bal\\'" . balance-mode)
     '("\\.gpi\\'" . gnuplot-mode)
     '("\\.lu\\'"  . lua-mode)
     '("\\.nqp\\'" . perl-mode)
     '("\\.php\\'" . html-mode)
     '("\\.pic\\'" . nroff-mode)
     '("\\.pl\\'"  . prolog-mode)
     '("\\.tex\\'" . latex-mode)
     '("\\.xr\\'"  . conf-xdefaults-mode)
     '("*"         . text-mode) )))
  (setf auto-mode-alist (nconc modes auto-mode-alist)) )

> in my init.el, the previously visited buffers that
> are automatically opened when I start emacs will
> still be in elisp-mode. The fix, of course is to
> invoke xah-elisp-mode from the minibuffer. This is
> certainly doable, even with multiple elisp buffers
> opened, but I'm always looking to
> eliminate redundancies.

No, that stinks, that should be automated.
I'm unfamiliar with this automatically opened
principle tho and if I have it (I don't think so)
I would like it inhibited, pretty please?

> It would be handy if there were a command that
> would set all visited buffers ending in a specific
> file extension to a specific mode. If such were
> available, it would come in handy for experimenting
> with alternative major modes.

Sure you can iterate all the buffers and apply
commands but this is just doing it manually in
a sense (only faster and with less effort). B/c the
files should turn up in the desired mode w/o
any intervention!

-- 
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal