Appendix A Frequently Asked Questions

• How can I change the indent level from 4 spaces to 2 spaces?

  Set the variable c-basic-offset. See Getting Started.

• Why doesn't the RET key indent the new line?

  Emacs' convention is that RET just adds a newline, and that C-j adds a newline and indents it. You can make RET do this too by adding this to your c-initialization-hook:

            (define-key c-mode-base-map "\C-m" 'c-context-line-break)
       

  See Getting Started. This is a very common question. If you want this to be the default behavior, don't lobby us, lobby RMS! :-)

• How do I stop my code jumping all over the place when I type?

  Deactivate “electric minor mode” with C-c C-l. See Getting Started.

• How do I reindent the whole file?

  Visit the file and hit C-x h to mark the whole buffer. Then hit C-M-\. See Indentation Commands.

• How do I reindent the current block?

  First move to the brace which opens the block with C-M-u, then reindent that expression with C-M-q. See Indentation Commands.

• I put (c-set-offset 'substatement-open 0) in my .emacs file but I get an error saying that c-set-offset's function definition is void. What's wrong?

  This means that CC Mode hasn't yet been loaded into your Emacs session by the time the c-set-offset call is reached, most likely because CC Mode is being autoloaded. Instead of putting the c-set-offset line in your top-level .emacs file, put it in your c-initialization-hook (see CC Hooks), or simply modify c-offsets-alist directly:

            (setq c-offsets-alist '((substatement-open . 0)))
       

• I have an open paren character at column zero inside a comment or multiline string literal, and it causes the fontification and/or indentation to go haywire. What gives?

  It's due to the ad-hoc rule in (X)Emacs that such open parens always start defuns (which translates to functions, classes, namespaces or any other top-level block constructs in the CC Mode languages). See Left Margin Paren, for details (See Defuns, in the Emacs 20 manual).

  This heuristic is built into the core syntax analysis routines in (X)Emacs, so it's not really a CC Mode issue. However, in Emacs 21.1 it became possible to turn it off¹ and CC Mode does so there since it's got its own system to keep track of blocks.