Re: distinguish .h files

[Tassilo Horn]

Oleksandr Gavenko <gavenko@bifit.com.ua> writes:

Hi Oleksandr,

>> Please have a look at
>>
>>    (info "(emacs) Choosing Modes")
>>
>    Third, Emacs tries to determine the major mode by looking at the
> text at the start of the buffer, based on the variable
> `magic-mode-alist'.  By default, this variable is `nil' (an empty
> list), so Emacs skips this step; however, you can customize it in your
> init file
>
> How long start of the buffer? Which variable control this behavior?

I don't know exactly, but in general only the first line is relevant,
with some shebang like

#!/bin/bash

But read a bit on:

,----[ (info "(emacs)Choosing Modes") ]
|    Alternatively, an element of `magic-mode-alist' may have the form
| 
|      (MATCH-FUNCTION . MODE-FUNCTION)
| 
| where MATCH-FUNCTION is a Lisp function that is called at the beginning
| of the buffer; if the function returns non-`nil', Emacs set the major
| mode wit MODE-FUNCTION.
`----

This should do the trick:

--8<---------------cut here---------------start------------->8---
(defun c++-header-file-p ()
  "Return non-nil, if in a C++ header."
  (and (string-match "\\.h$"
                     (or (buffer-file-name)
                         (buffer-name)))
       (save-excursion
         (re-search-forward "\\_<class\\_>" nil t))))

(add-to-list 'magic-mode-alist
             '(c++-header-file-p . c++-mode))
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo