Marius Hofert <marius.hofert@math.ethz.ch> writes:

Hi,

> What's the 'correct' approach to easily edit (change + save) such files?

not sure whats the 'correct' approach, but there is tramp which allows
you to do something like:

1. find-file as root

,---------------
| C-x C-f /sudo:
`---------------

and then asks for a password

,-----------------------------------
| Password for /sudo:root@localhost:
`-----------------------------------

to let you subsequently edit the file as root

2. or reopen dired buffer with sudo and thus open end edit files from
that buffer as root

,-------------------------------------------------------------------------------
| C-c C-s runs the command dired-toggle-sudo, which is an interactive autoloaded
| compiled Lisp function in `dired-toggle-sudo.el'.
|
| It is bound to C-c C-s.
|
| (dired-toggle-sudo &optional SUDO-USER)
|
| Reopen current file or dired buffer with sudo.
|
| If SUDO-USER is nil assume root.
|
| If called with `universal-argument' (C-u), ask for username.
`-------------------------------------------------------------------------------

But I finally ended up to write a separate minimal init.el file and a
small batch script that allow me to quickly open a root instance of
emacs when I need it that warns me about being root while editing that I
exit when I'm done with editing:

  ,---------------------------------------------
  | -rwxr-xr-x 1 me users  125 26. Apr 09:44 esu
  `---------------------------------------------

with content:

 ,------------------------------------------------------
 | #!/bin/sh
 | # start emacs as root
 |
 | exec sudo emacs -Q -bg black -fg wheat --no-splash -l
 | /home/me/.emacs.d/emacs-ESU-script.el
 `------------------------------------------------------

emacs-ESU-script.el:

(it starts up pretty fast, but makes editing convenient, and has a nice
red warning at the top of the buffer about editing as root)