Run sgml-pretty-print when opening xml file in emacs?

Question

Currently I can use sgml-pretty-print to print an XML file in emacs, but this is a manual process:

• M- <
• C space
• M →
• Mx sgml-pretty-print

I would like this to happen automatically (or at least have some kind of option). I am new to emacs / elisp and don't understand how:

• emacs knows what code to run when opening a file (does this start with files.el?)
• If you want to override this code with your own, how to do it

Answer 1

This should do the trick for you:

(add-hook 'find-file-hook 'my-sgml-find-file-hook)
(defun my-sgml-find-file-hook ()
  "run sgml pretty-print on the file when it opened (if it sgml)"
  (when (eq major-mode 'sgml-mode)
    (sgml-pretty-print (point-min) (point-max))))

find-file-hook, point-min (-max) major-mode.

elisp, question, , , .

Answer 2

. ~/.emacs :

(add-hook 'sgml-mode-hook #'(lambda ()
  (sgml-pretty-print (point-min) (point-max))))