I am not getting indentation or colors when I open a cpp/h file with my emacs/xemacs installation on windows. Could you please advise what I need to do in my settings file to make this happen?
Thanks
It's the auto-mode-alist variable that stores the modes that should be invoked in relation with the file extension. This variable is configured by default to associate c++-mode to cpp files.
See the content of auto-mode-alist by doing a C-h v auto-mode-alist RET.
You could also try to define the association by yourself like this :
(setq auto-mode-alist
(append '(("\\.\\(CC?\\|HH?\\)\\'" . c++-mode)
("\\.[ch]\\(pp\\|xx\\|\\+\\+\\)\\'" . c++-mode)
("\\.\\(cc\\|hh\\)\\'" . c++-mode)
) auto-mode-alist ))
Also note that .h files are by default considered C files, not C++.
Do your files have a cpp or c extension?
Please have a look at emacs faq
Related
How can I make latex-mode to apply to files with .tikz extension in Emacs? (I am using Auctex)
You can run M-x latex-mode in the file buffer. If you want to automatically do this for every file you visit add the following to .emacs,
(setq auto-mode-alist
(append
'(("\\.tikz\\'" . latex-mode))
auto-mode-alist))
auto-mode-alist is a list of file types and the mode to apply as you may have guessed. You can run C-h v auto-mode-alist to get a description of the variable for your emacs.
My Emacs opens .m files in ObjC mode. However I want to open them in Octave mode. I have already added to the .emacs file:
(autoload 'octave-mode "octave-mod" nil t)
(setq auto-mode-alist (cons '("\\.m$" . octave-mode) auto-mode-alist))
What else should I do? I do have Octave mode installed.
Fortunately everything is working now and unfortunately I don't remember how I fixed it :) Maybe there was an error in my .emacs earlier. This is the more correct code:
(add-to-list 'auto-mode-alist '("\\.m$" . octave-mode))
Autoloading is unneeded in recent versions; if you do need to enable it, note that "octave-mode" is not a typo.
(autoload 'octave-mode "octave-mod" nil t)
Use this.
;; octave-mode
(autoload 'octave-mode "octave-mode" "Loding octave-mode" t)
(add-to-list 'auto-mode-alist '("\\.m\\'" . octave-mode))
Just ran into this exact problem.
Your statement is correct, but your .emacs file probably isn't loading up correctly. Emacs searches the "HOME" variable to load up preferences, lisp code etc.
To see what your HOME variable is:
Open scratch buffer (this is a "play place" to try things out):
C-x C-b *scratch* <RET>
Evaluate this expression by typing it, then putting the cursor to the right, then hitting C-x C-e
insert (getenv "HOME")
Emacs will display your home path at the bottom (mine defaulted to ...Documents and Settings\UserName)
I haven't worked out a good way to change it, but you're supposed to be able to simply add HOME as an environment variable (that didn't work for me).
It's also talked about a bit more over here:
http://www.gnu.org/software/emacs/manual/html_node/emacs/Windows-HOME.html
Also remember that the file has to be ".emacs" and not myConfig.emacs or something of the like. Use bash command ren to rename the file (windows explorer won't let you have nameless files)
My Emacs opens .m files in ObjC mode. However I want to open them in Octave mode. I have already added to the .emacs file:
(autoload 'octave-mode "octave-mod" nil t)
(setq auto-mode-alist (cons '("\\.m$" . octave-mode) auto-mode-alist))
What else should I do? I do have Octave mode installed.
Fortunately everything is working now and unfortunately I don't remember how I fixed it :) Maybe there was an error in my .emacs earlier. This is the more correct code:
(add-to-list 'auto-mode-alist '("\\.m$" . octave-mode))
Autoloading is unneeded in recent versions; if you do need to enable it, note that "octave-mode" is not a typo.
(autoload 'octave-mode "octave-mod" nil t)
Use this.
;; octave-mode
(autoload 'octave-mode "octave-mode" "Loding octave-mode" t)
(add-to-list 'auto-mode-alist '("\\.m\\'" . octave-mode))
Just ran into this exact problem.
Your statement is correct, but your .emacs file probably isn't loading up correctly. Emacs searches the "HOME" variable to load up preferences, lisp code etc.
To see what your HOME variable is:
Open scratch buffer (this is a "play place" to try things out):
C-x C-b *scratch* <RET>
Evaluate this expression by typing it, then putting the cursor to the right, then hitting C-x C-e
insert (getenv "HOME")
Emacs will display your home path at the bottom (mine defaulted to ...Documents and Settings\UserName)
I haven't worked out a good way to change it, but you're supposed to be able to simply add HOME as an environment variable (that didn't work for me).
It's also talked about a bit more over here:
http://www.gnu.org/software/emacs/manual/html_node/emacs/Windows-HOME.html
Also remember that the file has to be ".emacs" and not myConfig.emacs or something of the like. Use bash command ren to rename the file (windows explorer won't let you have nameless files)
Does anyone know how I might get emacs to apply the ".ini" syntax highlighting for a ".gcf" file (my own custom file ext)?
I've googled, and my best effort was adding to my ~/.emacs, without joy.
(add-to-list 'auto-mode-alist '("[.]gcf$" . ini-mode))
First find out the mode for ini files. While editing a ".ini" file do C-h m; then add to your ".emacs" the following code:
(setq auto-mode-alist (cons '(".*\.gcf$" . YOUR-MODE) auto-mode-alist))
What lines should I add to my _emacs (on Windows) file to have it open .h files in C++ mode? The default is C mode.
Try this:
(add-to-list 'auto-mode-alist '("\\.h\\'" . c++-mode))
Whenever you open .h files, C++-mode will be used.
Another approach for using both c-mode and c++-mode as appropriate, is to use directory local variables to set the mode.
Directory variables are evaluated after the mode has been set1, so you can actually write a .dir-locals.el file for your C++ project containing this:
((c-mode . ((mode . c++))))
And Emacs will change the mode to c++-mode whenever it had initially set it to c-mode.
If you work with a mix of C and C++ projects, this makes for a pretty trivial solution on a per-project basis.
Of course, if the majority of your projects are C++, you might set c++-mode as the default2, and you could then use this approach in reverse to switch to c-mode where appropriate.
1 normal-mode calls (set-auto-mode) and (hack-local-variables) in that order. See also: How can I access directory-local variables in my major mode hooks?
2 To do so, add
(add-to-list 'auto-mode-alist '("\\.h\\'" . c++-mode))
to your .emacs file which open .h files in C++ mode by default.
If you don't want this to apply to every .h file, you can add the following to the bottom of your C++ header files.
// Local Variables:
// mode: c++
// End:
This will work for any Emacs variables that you want to set on a per file basis. Emacs ignores the leading characters, so use whatever comment characters are appropriate for the file type.
Apparently you can also put this at the top of the file:
// -*-c++-*-
to tell Emacs it's a C++ file.
I use this since I quite frequently end up on a vanilla Emacs and it works without configuring Emacs in any way.
Since I use both C and C++ regularly, I wrote this function to try and "guess" whether a .h file is meant to be C or C++
;; function decides whether .h file is C or C++ header, sets C++ by
;; default because there's more chance of there being a .h without a
;; .cc than a .h without a .c (ie. for C++ template files)
(defun c-c++-header ()
"sets either c-mode or c++-mode, whichever is appropriate for
header"
(interactive)
(let ((c-file (concat (substring (buffer-file-name) 0 -1) "c")))
(if (file-exists-p c-file)
(c-mode)
(c++-mode))))
(add-to-list 'auto-mode-alist '("\\.h\\'" . c-c++-header))
And if that doesn't work I set a key to toggle between C and C++ modes
;; and if that doesn't work, a function to toggle between c-mode and
;; c++-mode
(defun c-c++-toggle ()
"toggles between c-mode and c++-mode"
(interactive)
(cond ((string= major-mode "c-mode")
(c++-mode))
((string= major-mode "c++-mode")
(c-mode))))
It's not perfect, there might be a better heuristic for deciding whether a header is C or C++ but it works for me.
I could swear I saw this question answered appropriately already? Weird.
You want this:
(add-to-list 'auto-mode-alist '("\\.h\\'" . c++-mode))