How can I make emacs save all my files with spaces instead of tabs, without manually having to run untabify?
What about this?
(add-hook 'write-file-hooks (lambda () (untabify (point-min) (point-max))))
Problem: You probably do not want to put it on
write-file-hooks. Think of Makefiles…
write-content-hooksinstead, and make them local to the buffer
(defun ska-untabify () "My untabify function as discussed and described at http://www.jwz.org/doc/tabs-vs-spaces.html and improved by Claus Brunzema: - return nil to get `write-contents-hooks' to work correctly (see documentation there) - `make-local-hook' instead of `make-local-variable' - when instead of if Use some lines along the following for getting this to work in the modes you want it to: \(add-hook 'some-mode-hook '(lambda () (make-local-hook 'write-contents-hooks) (add-hook 'write-contents-hooks 'ska-untabify nil t)))" (save-excursion (goto-char (point-min)) (when (search-forward "\t" nil t) (untabify (1- (point)) (point-max))) nil))
This caused me some severe headaches. I believe TabsAreEvil, but this kind of approach can seriously screw with other peoples formatting, especially if they have a different default-tab-width setting to you. I attached it to my c-mode write hook. I have now taken a different approach, using font highlighting to catch the little buggers in the bits i edit. – TimOCallaghan – See EightyColumnRule and ShowWhiteSpace.
This still creates problems if you use one emacs session to edit different types of files. I have the following in my .emacs file:
(defun c++-mode-untabify () (save-excursion (goto-char (point-min)) (while (re-search-forward "[ \t]+$" nil t) (delete-region (match-beginning 0) (match-end 0))) (goto-char (point-min)) (if (search-forward "\t" nil t) (untabify (1- (point)) (point-max)))) nil) (add-hook 'c++-mode-hook '(lambda () (make-local-hook 'write-contents-hooks) (add-hook 'write-contents-hooks 'c++-mode-untabify)))
The problem is that after I open a C++ file, all subsequent file writes will call
add-hook 'c++-mode-hook bit does not create hook that only gets called when saving C++ buffers, or only for the current buffer. Instead, the c++ mode hooks are run when first loading C++ mode, and this hook adds
c++-mode-untabify to the
write-contents-hooks that are executed for all buffers. So if I load a C++ file and then in the same session open a tab-delimited text file, I can’t edit and save the text file without having
c++-mode-untabify run on the buffer.
Does anyone know how set a write contents hook that only applies to a given buffer or file type, or how to clear
write-contents-hooks when changing to buffers using other major-modes? --DanielMcPherson?
Edit: I see now.
make-local-hook is obsolete as of 21.1. Instead,
add-hook now takes an optional argument for making a hook buffer-local. The
add-hook part should be: (add-hook ‘c++-mode-hook ‘(lambda () (add-hook ‘write-contents-hooks ‘c++-mode-untabify nil t)))
c++-mode-untabify could check the current mode:
(defun c++-mode-untabify () (if (string= (substring mode-name 0 3) "C++") (save-excursion (delete-trailing-whitespace) (untabify (point-min) (point-max)))))
Thanks to Boojum on StackOverflow? for this answer. See http://stackoverflow.com/questions/318553/getting-emacs-to-untabify-when-saving-files. --DanielMcPherson?
I just have the following in my init file, which does nothing fancy at all and works exactly as you’d want it to:
;; no tabs by default. modes that really need tabs should enable ;; indent-tabs-mode explicitly. makefile-mode already does that, for ;; example. (setq-default indent-tabs-mode nil)
;; if indent-tabs-mode is off, untabify before saving (add-hook 'write-file-hooks (lambda () (if (not indent-tabs-mode) (untabify (point-min) (point-max)))))
Edit: I’ve been using Joost’s ‘nothing-fancy’ hook as above, but as of v24, this seems to block files being saved. I believe this is because the hook should return nil to signify that it hasn’t performed the write itself … hence
;; if indent-tabs-mode is off, untabify before saving (add-hook 'write-file-hooks (lambda () (if (not indent-tabs-mode) (untabify (point-min) (point-max))) nil ))
I tried Joosts hook just a moment ago, without noticing Tims update. I suggest updating Joosts example with nil return, or change to using the before-save-hook rather than write-file-hooks.