Indent with spaces not TABs (GNU Gnulib)

1.4.2 Indent with spaces not TABs

We use space-only indentation in nearly all files. This includes all *.h, *.c, *.y files, except for the regex module. Makefile and ChangeLog files are excluded, since TAB characters are part of their format.

In order to tell your editor to produce space-only indentation, you can use these instructions.

For Emacs: Add these lines to your Emacs initialization file ($HOME/.emacs or similar):

;; In Gnulib, indent with spaces everywhere (not TABs).
;; Exceptions: Makefile and ChangeLog modes.
(add-hook 'find-file-hook '(lambda ()
  (if (and buffer-file-name
           (string-match "/gnulib\\>" (buffer-file-name))
           (not (string-equal mode-name "Change Log"))
           (not (string-equal mode-name "Makefile")))
      (setq indent-tabs-mode nil))))

For vi (vim): Add these lines to your $HOME/.vimrc file:
```
" Don't use tabs for indentation. Spaces are nicer to work with.
set expandtab
```
For Makefile and ChangeLog files, compensate for this by adding this to your $HOME/.vim/after/indent/make.vim file, and similarly for your $HOME/.vim/after/indent/changelog.vim file:
```
" Use tabs for indentation, regardless of the global setting.
set noexpandtab
```
For Eclipse: In the “Window|Preferences” dialog (or “Eclipse|Preferences” dialog on Mac OS),
1. Under “General|Editors|Text Editors”, select the “Insert spaces for tabs” checkbox.
2. Under “C/C++|Code Style”, select a code style profile that has the “Indentation|Tab policy” combobox set to “Spaces only”, such as the “GNU [built-in]” policy.
If you use the GNU indent program, pass it the option --no-tabs.