How to force spaces instead of tabs regardless of major mode?

Question

I want all tabs to be 4 spaces. I have the following in .emacs

(setq-default indent-tabs-mode nil)
(setq c-basic-indent 4)
(setq tab-width 4)

But this gets overwritten by some of the major mode themes that I can use. Is there a way to force this issue through my .emacs file?

Answer 1

Try this to overwrite whatever any major mode overwrites:

(add-hook 'after-change-major-mode-hook 
          '(lambda () 
             (setq-default indent-tabs-mode nil)
             (setq c-basic-indent 4)
             (setq tab-width 4)))

Note though that major modes that aren't based on c-mode are not likely to care about c-basic-indent and may potentially use their own, mode-specific indentation variables. In such cases, there's no way around configuring these variables manually.

Answer 2

Declare a default C indentation style, rather than declaring specific style parameters.

(setq c-default-style "k&r2")  ;; or whatever your preference is
(set-default 'indent-tabs-mode nil)