In emacs, org-mode has been enabled and have opened some *.org files. Now in the init.el file i am trying to enable the outline-minor-mode in order to fold the lines starting with ";" . When i try to evaluate the (outline-minor-mode) command i get the message "Symbol's function definition is void: th-outline-minor-mode-init"
Seems like the org-mode sets up the outline-minor-mode-hook
outline-minor-mode-hook's value is (th-outline-minor-mode-init)
This variable may be risky if used as a file-local variable.
How to setup the outline-minor-mode for init.el file so that the ";" is treated as heading.
Note:- When emacs is launched with --no-init-file option, outline-minor-mode works for init.el file
Doesn't org-mode use an org- prefix pretty consistently?
On that assumption, th-outline-minor-mode-init doesn't look like an org-mode function to me, so something else is probably at fault, and you'll need to find out what.
Obviously you can't find-function if it's void, so I'd just M-x rgrep your config for th-outline-minor-mode-init (or most likely searching for (add-hook 'outline-minor-mode-hook 'th-outline-minor-mode-init will find the culprit directly).
That issue aside, I happen to use outline-minor-mode in my init file (with headers being lines beginning with ;;;;, and auto-folding the ones beginning with ;;;; *), using the following Local Variables block at the end of the file:
;;; Local Variables:
;;; outline-regexp: ";;;; "
;;; eval:(progn (outline-minor-mode 1) (while (re-search-forward "^;;;; \\* " nil t) (outline-toggle-children)))
;;; End:
I keep a lot of documentation in the file, and with <backtab> bound to outline-toggle-children I find this a pretty convenient way to access it.
Related
When I am using Emacs to edit a ".s" file, I want to change the comment from ";;" to "//". I can't seem to find out how to change the comment identifiers?
For example, when I comment-region.
More information:
I appear to be in ASM-MODE which is the default mode for editing assembler files. I made sure that I was in asm-mode by
(setq auto-mode-alist
(append '(("\\.s$" . asm-mode)auto-mode-alist))
Because assembly programs typically use ; as the comment indicator, asm-mode uses this. However, for some reason I cannot figure the GNU assembler (GNU Binutils for Raspbian) 2.35.2 uses // or # or # for comments NOT a ;
Therefore, I would like to change the behaviour such that when I select a region and M-X comment-region it uses either // or # for comments. I cannot use the default comment character, I need to change it to either double-slashes // or an at symbol #
The question is really how do I go about changing the default comment character for in a mode?
Assuming that the major mode of the .s file is asm-mode, you can use the mode hook to tweak the comment start string:
(defun my/asm-comment-tweak ()
(setq-local comment-start "// "))
(eval-after-load "asm"
(add-hook 'asm-mode-hook #'my/asm-comment-tweak))
Adding the above to your init file should let you open a .s file, which will be in asm-mode. The last thing that is done by asm-mode is to run the mode hook which will call the function my/asm-comment-tweak: the function will set the buffer-local variable comment-start to the string you specified.
This pattern is very common: many problems in customizing emacs are solved in exactly the same way. You define a function that tweaks a variable and you arrange for the function to be called by the appropriate mode hook.
I downloaded two .el files
One is to highlight current column where cursor is and another one to highlight some specific words.
I followed next steps in the file:
(add-to-list 'load-path "~/.xemacs/packages/") //path where I saved .el files
(load "column-marker") //name of file without .el extension
To this step it works fine, I find those when I press M-x column-marker and I can use it.
My problem begins when I want to use it everytime i open emacs and I found that I could use something similar to this:
(add-to-list 'auto-mode-alist '("\\.js\\'" . js2-mode))
Which in my case I am typing:
(add-to-list 'auto-mode-alist '("\\.\\'" . column-marker)) //I want to enable it for all .something files
But... when doing that, there is an error when opening emacs and it starts with default setup.
What am I doing wrong? I have tried many ways and none work.
Thanks in advance
Always post the error message you see. That helps others help you.
C-h f auto-mode-alist tells you that the functions you use in it must implement major modes. column-marker is not a major-mode function. It is not even a function; it is a file.
What you need to do, for each mode where you want some function in file column-marker.el to be invoked, is to put that function on the major-mode hook for that function. For example:
(add-hook 'emacs-lisp-mode (lambda () (interactive) (column-marker-1 80))
And lo and behold, what does the Commentary in file column-marker.el tell you?
;; Installation: Place this file on your load path, and put this in
;; your init file (`.emacs'):
;;
;; (require 'column-marker)
;;
;; Other init file suggestions (examples):
;;
;; ;; Highlight column 80 in foo mode.
;; (add-hook 'foo-mode-hook (lambda () (interactive) (column-marker-1 80)))
Couldn't be clearer. Provided you actually read it.
Seriously, a minimum of investigation is in order, before you post a question to StackOverflow. You should do a Google search, open README files and read them, and so on --- first. And in the case of Emacs questions, IMHO, you should ask Emacs first (e.g. C-h v auto-mode-alist).
According to the rules of S.O. posting, not doing preliminary simple research is even grounds for closing a question. So do not be surprised if this question gets closed or downvoted.
I put the following in my .emacs file:
(require 'dired-x)
(add-hook 'dired-load-hook '(lambda () (require 'dired-x)))
(setq dired-omit-files-p t)
(setq dired-omit-files
(concat dired-omit-files "\\|^\\..+$\\|-t\\.tex$\\|-t\\.pdf$"))
But C-x d still shows me .pdf and .tex files. Did I get the syntax wrong in that last line?
Bonus question: Is there a way to get Dired to hide hidden directories, like .git folders?
A simple and very general solution which doesn't rely on any extras is to do C-u s to change the ls flags and immediately refresh (that is, C-u s takes care of refreshing also, so there is very little typing involved). Usually you will want to remove -a to hide dotfiles. But you can do everything you're already able to do in the shell console, which is far more than what a simple toggle mode could offer (at the cost of some extra keypressings). And there is a history of previous flags available, so "toggling" is pretty fast too.
Your regexp will match *-t.tex files, not *.tex ones.
With recent version of Emacs, it should be sufficient to add the following section to ~/.emacs to filter what you want:
(require 'dired-x)
(setq-default dired-omit-files-p t) ; this is buffer-local variable
(setq dired-omit-files
(concat dired-omit-files "\\|^\\..+$\\|\\.pdf$\\|\\.tex$"))
Update: by default, dired-omit-files regexp filters out special directories . and ... If you don't want this behavior, you can just override defaults (instead of inheriting them with concat):
(setq dired-omit-files "^\\.[^.]\\|\\.pdf$\\|\\.tex$")
The regexp ^\\.[^.] will match any string of length 2+ starting with a dot where second character is any character except the dot itself. It's not perfect (will not match filenames like "..foo"), but should be ok most of the time.
I work on an open source project where the creator sets his tab-indents to 2 spaces.
I'd like to just enable it on the fly for the one file I work on and not other files of the same type. There must be something like M-x set-tab-indent. It is a JavaScript file ending in .js.
I know I can use:
(setq-default tab-width int)
inside my .emacs file, but I rather just call an M-x command to set it and forget it during my duration of working on this file. I tried M-x apropos and Google but couldn't find the specific command.
Thanks.
You can make the variable js-indent-level local to the buffer using:
M-x make-variable-buffer-local <RET> js-indent-level <RET>
Then you can set that variable in the buffer using:
M-x set-variable <RET> js-indent-level <RET> 2
The easiest way to do this for a single buffer is to use M-x set-variable.
Type M-x set-variable and press enter
When prompted for the variable to set, set tab-width then press enter
You'll be prompted with the line Set tab-width (buffer-local) to value:.
Put the value you want, then hit enter
The buffer should instantly be updated with the new value.
You could also use file local variables to automate omrib's solution for that one file, by adding this to it:
// Local Variables:
// js-indent-level: 2
// indent-tabs-mode: nil
// End:
Create a file ".dir-locals.el" in the project's directory and fill it like this:
((nil . ((tab-width . 2))))
This will take care of setting tab-width automatically and you don't have to modify the actual file (which is likely version-controlled.)
See the manual for more information about the format. I believe this requires Emacs 23.
As indicated by others, one issue with the File Local Variables approach is that you need to modify the file, and that's not ideal if you need to keep those declarations out of version control.
If you want the variables to apply to all files under a given directory, then Directory Local Variables is obviously the way to go, and you can implement that with either a .dir-locals.el file, or by calling (dir-locals-set-directory-class):
http://www.emacswiki.org/emacs/DirectoryVariables
http://www.gnu.org/software/emacs/manual/html_node/emacs/Directory-Variables.html
I prefer the directory class approach myself, and I was thinking that it's a shame that there isn't an analogous approach for file local variables, but I found that the directory class code actually works perfectly with files, and the only issue is that dir-locals-set-directory-class calls file-name-as-directory on its argument, which prevents it from being matched, due to the trailing slash.
The following therefore is a way to configure directory local variables for a single file, without modifying the file itself, or affecting other files under the same parent directory.
(defun my-file-locals-set-directory-class (file class &optional mtime)
"Enable 'directory local' classes for individual files,
by allowing non-directories in `dir-locals-directory-cache'.
Adapted from `dir-locals-set-directory-class'."
(setq file (expand-file-name file))
(unless (assq class dir-locals-class-alist)
(error "No such class `%s'" (symbol-name class)))
(push (list file class mtime) dir-locals-directory-cache))
(dir-locals-set-class-variables
'my-javascript-class
'((nil . ((js-indent-level . 2)
(indent-tabs-mode . nil)))))
(my-file-locals-set-directory-class
"path/to/the/file.js" 'my-javascript-class)
I use a snippet of code in my init.el that tries to auto-detect files that use 2-space indents, and switch Emacs's indentation for that file to 2 spaces when it sees such files:
(add-hook 'js-mode-hook
(lambda ()
(when (string-match-p "^ [A-Za-z]" (buffer-string))
(make-variable-buffer-local 'js-indent-level)
(set-variable 'js-indent-level 2))))
I want to load my file named "my-c-setup.el" when the c-mode is loading. So, I'm using the function "autoload".
With my python setup, it works well :
lang.el
(autoload 'python-mode "my-python-setup" "" t)
my-python-setup.el
(require 'python)
; ...
I'm trying to do the same with the c-mode, but i does not work :
lang.el
(autoload 'c-mode "my-c-setup" "" t)
my-c-setup.el
(setq c-basic-offset 4)
; ...
When I try to open a file in c-mode (test.c for example), I have the following error :
File mode specification error: (error "Autoloading failed to define function c-mode")
Autoload is not what you're looking for. What it does is simply load some code the first time it is needed, which is a handy way to extend Emacs' functionality while still keeping the start-up time low.
To solve your problem, we gotta think about what you really want to do: do you simply want some of your code to be loaded at some point, or do you want buffer-local customizations for ever buffer that is in c-mode?
If you simply want Emacs to load your code at start-up, either put your code directly into your .emacs file or use load-file or require instead of autoload:
load-file simply takes a file name, loads the lisp code in that file and evaluates it. So if your code is in a file named "/path/to/my-c-setup.el", you could put the following line in your .emacs, and the code will be loaded on every start-up:
(load-file "/path/to/my-c-setup.el")
Perhaps you don't want to give the absolute path name for every file you load. In that case, you could use the function load-library instead which is similar to load-file but tries to find the given filename in any of the directories stored in the variable load-path:
(add-to-list 'load-path "/path/to")
(load-library "my-c-setup.el")
The advantage is that you have to do the add-to-list part only once, and all subsequent calls to load-library will be able to find code in that directory.
An alternative way is the provide/require mechanism: you can make your .el-file "provide" some feature by putting a (provide 'feature) call in it, e.g.
(provide 'my-c-mode-customizations)
Then put an according (require 'feature) in your .emacs file, and your code will be loaded as well:
(require 'my-c-mode-customizations)
However, if you want your code only be loaded when c-mode is activated on a buffer, the way to achieve that is through Emacs' Hook mechanism:
A hook is a variable where you can
store a function or functions to be
called on a particular occasion by an
existing program.
Most major modes provide a customizable hook variable to which you can add functions that will be called whenever the major mode is invoked. For instance, c-mode provides c-mode-hook. In order for your own customizations to be called whenever c-mode is turned on for a buffer, put them in a function, say, my-c-mode-customizations and add the following line to your .emacs file:
(add-hook 'c-mode-hook 'my-c-mode-customizations)
Of course, you still need autoload for Emacs to actually find the definition of that function.
Lisp's autoload does not call a function when a file is loaded but tells lisp that the function is available and that the given file provides it. Whenever someone calls the (not yet defined) function, the file is loaded.
I think that c-mode is already defined and thus fails to re-register.
Autoload doesn't do what you think it does.
http://www.gnu.org/software/emacs/elisp/html_node/Autoload.html
What you probably want are mode-hooks or eval-after-load.
See eval-after-load vs. mode hook for the difference between the two.