Disable flycheck-mode and prettify-symbols-mode - emacs

My emacs.d clones from purcell/emacs.d: An Emacs configuration bundle with batteries included
It enable prettify-symbols-mode and flycheck-mode as default.
Search the custom.el but did not find related setting .
How could disable them from my init.el?

(prettify-symbols-mode -1)
C-h f prettify-symbols-mode:
prettify-symbols-mode is an interactive compiled Lisp function in
‘prog-mode.el’.
(prettify-symbols-mode &optional ARG)
Toggle Prettify Symbols mode.
With a prefix argument ARG, enable Prettify Symbols mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.
When Prettify Symbols mode and font-locking are enabled, symbols are
prettified (displayed as composed characters) according to the rules
in ‘prettify-symbols-alist’ (which see), which are locally defined
by major modes supporting prettifying. To add further customizations
for a given major mode, you can modify ‘prettify-symbols-alist’ thus:
(add-hook 'emacs-lisp-mode-hook
(lambda ()
(push '("<=" . ?≤) prettify-symbols-alist)))
You can enable this mode locally in desired buffers, or use
‘global-prettify-symbols-mode’ to enable it for all modes that
support it.
This applies to almost every minor mode.

Related

Showing line numbers in dired file browser in Emacs

I am unable to show line numbers in Emacs when browsing files using Dired.
Dotspacemacs-line-numbers '(:relative nil
:visual t
:disabled-for-modes ;; dired-mode
doc-view-mode
markdown-mode
;; org-mode
pdf-view-mode
;; text-mode
:size-limit-kb 1000)
but line numbers are not showing.
any idea how to enable line numbers in Dired?
Turn on minor mode display-line-numbers-mode:
M-x display-line-numbers-mode. C-h f tells you:
display-line-numbers-mode is an autoloaded interactive compiled Lisp
function in display-line-numbers.el.
(display-line-numbers-mode &optional ARG)
Toggle display of line numbers in the buffer.
This uses display-line-numbers internally.
This is a minor mode. If called interactively, toggle the
Display-Line-Numbers mode mode. If the prefix argument is positive,
enable the mode, and if it is zero or negative, disable the mode.
If called from Lisp, toggle the mode if ARG is toggle. Enable the
mode if ARG is nil, omitted, or is a positive number. Disable the
mode if ARG is a negative number.
To check whether the minor mode is enabled in the current buffer,
evaluate display-line-numbers-mode.
The mode’s hook is called both when the mode is enabled and when it is
disabled.
To change the type of line numbers displayed by default,
customize display-line-numbers-type. To change the type while
the mode is on, set display-line-numbers directly.
Probably introduced at or before Emacs version 26.1.

How to know emacs true mode names?

Sometimes I copy configuration options from the Internet to my .emacs. Sometimes they don't work.
(add-hook 'laTeX-mode-hook 'turn-on-flyspell)
doesn't work:
(add-hook 'LaTeX-mode-hook 'turn-on-flyspell)
(notice the uppercase in Latex). But,
(add-hook 'flyspell-mode-hook 'flyspell-buffer)
is correct. Although Emacs shows "Fly" in the lower bar and also M-: major-mode shows latex-mode and not Latex-mode.
How do I know how to write emacs modes name?
It sounds like you're actually more interested in the names of modes' hook variables than in the modes themselves.
You have several options. I will suggest some, based around discovering flyspell-mode-hook:
M-x apropos-variable RET flyspell RET, then search the results buffer for hook
C-h v flyspell-, then tab-complete
Any time you are in the minibuffer tab-completion is a good thing to try
M-x find-function flyspell-mode RET will open up the source code for flyspell, you can then search for hook
If you have configured your Emacs to provide completion for Emacs Lisp, you can simply type
(add-hook 'flyspell-
into your .emacs buffer and let Emacs suggest valid completion
Tools like Helm and ido can simplify the process of finding things
Using the find-function technique with latex-mode (which I tab-completed), I discovered that my version of Emacs calls its LaTeX mode function latex-mode. Searching for LaTeX- showed me that LaTeX-mode is an alias for latex-mode.
Your use of M-: major-mode is good, and gives you the correct major mode name (i.e. the symbol name for the mode function).
I don't believe there's a standard function to list the symbol names for the current buffer's enabled minor modes, but you can see all (loaded) minor mode symbols with C-hv minor-mode-list, so it's not hard to verify a name if you find you need to.
The symbol name for a mode's hook is literally the mode's symbol name with the suffix -hook.
Minor modes also have (in addition) an -on-hook and -off-hook.
The hook variables don't necessarily exist when not in use, but this naming is hard-coded in the standard macros for defining modes (and running their hooks at the appropriate times); and the modes which don't use those macros invariably follow the same conventions, to ensure consistency.

In Emacs, how to disable auto-fill-paragraph mode when in php-mode?

Normally, I need to enable the auto-fill-mode, so I have it turned on in .emacs. But when editting PHP in php-mode, I'd like to not use auto-fill-mode. Is there way to set it in .emacs such that when I'm in PHP mode, the auto-fill-paragraph mode is automatically turned off and when I leave php-mode, it's automatically turned on, barring other overriding?
Update: a closer examination of the .emacs revealed that auto-fill is set up by
(custom-set-variables
;; custom-set-variables was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
'(column-number-mode t)
...
'(text-mode-hook (quote (turn-on-auto-fill text-mode-hook-identify)))
...)
Some major-modes inherit certain settings from other modes (e.g., text-mode is used by many popular major modes). The following code snippet can be used to disable a feature for a particular major-mode using its mode hook:
(add-hook 'php-mode-hook (lambda ()
(auto-fill-mode -1) ))
It is sometimes helpful to check and see whether a particular feature has been enabled globally or locally, which in turn can give a clue as to whether that feature has been inherited by a major mode. In this case, the documentation for auto-fill-mode states as follows -- https://www.gnu.org/software/emacs/manual/html_node/emacs/Auto-Fill.html:
"Auto Fill mode is a buffer-local minor mode (see Minor Modes) in which lines are broken automatically when they become too wide. Breaking happens only when you type a <SPC> or <RET>."

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

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.
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.
TLDR: Use latex-mode or LaTeX-mode (they mean the same thing), no need to change auto-mode-alist, and use LaTeX-mode-hook for hooking into AucTeX.
Setting up AucTeX can be quite confusing, because it uses advice to override Emacs' built-in support for TeX and friends.
So, after installing AucTeX from ELPA, you should see the following in C-h f latex-mode:
This function has :override advice: ‘TeX-latex-mode’.
Same for all the other tex modes, though the list of modes that AucTeX overrides depends on the value of the TeX-modes variable.
The function LaTeX-mode is not defined in AucTeX (any more?): it's defined in core Emacs, with a cryptic comment about compatibility:
;; The following three autoloaded aliases appear to conflict with
;; AUCTeX. However, even though AUCTeX uses the mixed case variants
;; for all mode relevant variables and hooks, the invocation function
;; and setting of `major-mode' themselves need to be lowercase for
;; AUCTeX to provide a fully functional user-level replacement. So
;; these aliases should remain as they are, in particular since AUCTeX
;; users are likely to use them.
;; Note from Stef: I don't understand the above explanation, the only
;; justification I can find to keep those confusing aliases is for those
;; users who may have files annotated with -*- LaTeX -*- (e.g. because they
;; received them from someone using AUCTeX).
;;;###autoload
(defalias 'TeX-mode #'tex-mode)
;;;###autoload
(defalias 'plain-TeX-mode #'plain-tex-mode)
;;;###autoload
(defalias 'LaTeX-mode #'latex-mode)
What this all means is that, at least in 2021, you do not need to change auto-mode-alist to use AucTeX; just installing it is enough for it to override Emacs' builtin functionality.
Unfortunately, there's one last source of confusion. Even though LaTeX-mode is now mostly just a useless alias for latex-mode, it turns out that code in AucTeX that overrides latex-mode does not call latex-mode-hook (it calls LaTeX-mode-hook, which is different. So the LaTeX- variables, which are the AucTeX ones (as opposed to the lowercase ones that are builtin with Emacs), are still useful.

how to enable Show-Paren mode only for *.el files

How can I enable Show-Paren mode only for *.el files?
I have tried
(add-hook 'emacs-lisp-mode-hook '(lambda()
(show-paren-mode 1)
))
But it still enables Show-Paren mode for all the cases. Even in *scratch* buffer I have Show-Paren mode enabled.
As already said, show-paren-mode is a global minor mode. That said, one might be able to run it only on some buffer with something like:
(show-paren-mode) ;; activate the needed timer
(setq show-paren-mode ()) ;; The timer will do nothing if this is nil
(defun show-paren-local-mode ()
(interactive)
(make-local-variable 'show-paren-mode) ;; The value of shom-paren-mode will be local to this buffer.
(setq show-paren-mode t))
(add-hook 'emacs-lisp-mode-hook 'show-paren-local-mode)
It's untested, it might not work. Looking at the doc in might work, but looking at the code it might work. This might work only with some version of show-paren-mode.
show-paren-mode is a global minor-mode. It means exactly how it sounds.
This is very much by design, as most people (myself included) find this
minor-mode helpful across all buffers. Why do you want to disable it for any
file?
from the documentation
Show Paren mode is a global minor mode. When enabled, any
matching parenthesis is highlighted in show-paren-style' after
show-paren-delay' seconds of Emacs idle time.
Your code is correct. However, you should consider the fact that the *scratch* buffer's major mode is lisp-interaction-mode which derives from emacs-lisp-mode (which is mostly irrelevant) and the mode's definition:
(define-minor-mode show-paren-mode
"Toggle visualization of matching parens (Show Paren mode).
With a prefix argument ARG, enable Show Paren mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.
Show Paren mode is a global minor mode. When enabled, any
matching parenthesis is highlighted in `show-paren-style' after
`show-paren-delay' seconds of Emacs idle time."
:global t :group 'paren-showing
...)
:global t is the key thing here - the mode is global and is enabled in all buffers regardless of their major mode.
I think you can use
(setq-default show-paren-data-function #'ignore)
(show-paren-mode)
to formally enable the mode but keeping it quiet. And then something like
(defun set-up-emacs-lisp-mode ()
(setq-local show-paren-data-function #'show-paren--default))
(add-hook 'emacs-lisp-mode-hook #'set-up-emacs-lisp-mode)
to enable it in Emacs Lisp buffers. I've not tested this set-up, only the opposite (usually enabled, disabled just in Text Mode).
I used to use (setq-local show-paren-mode nil) but this makes Emacs highlight the braces in Ido promps, so I prefer (setq-default show-paren-data-function #'ignore).