What is the difference of tex-mode and latex-mode and LaTeX-mode in emacs

auctex, emacs

Solution

The modes provided by AUCTeX are listed at https://www.gnu.org/software/auctex/manual/auctex.html#Modes-and-Hooks and they are

- `plain-TeX-mode`

- `LaTeX-mode`

- `ams-TeX-mode`

- `ConTeXt-mode`

- `Texinfo-mode`

- `docTeX-mode`

Instead,

- `tex-mode`

- `plain-tex-mode`

- `latex-mode`

- `slitex-mode`

- `doctex-mode`

(note the different capitalization) are the major modes provided by the TeX mode package shipped with Emacs.

If you want to open all `*.tex` files with AUCTeX LaTeX mode add this to your `.emacs`:

(add-to-list 'auto-mode-alist '("\\.tex$" . LaTeX-mode))

Actually, this shouldn't be necessary, because AUCTeX defines the `tex-mode.el` mode names as alias of its own modes.

Problem

I am configuring AUCTeX in emacs. Most of the configurations are put in a LaTeX-mode-hook. When I open a main.tex file, I notice that the major mode is latex-mode and my hooked configurations are not activated. I have to M-x Tex-latex-mode to activate them. But the major-mode is still latex-mode. ``` (add-hook 'LaTeX-mode-hook (lambda () ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; auctex (setq TeX-auto-save t) (setq TeX-parse-self t) )) ``` So I would like to know what is the difference of these modes and how can I turn on AUCTeX automatically when I open a *.tex file.

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