Re: How to change and save a read-only file?

[Richard Copley <rcopley@gmail.com>]

On 29 June 2013 14:30, Emanuel Berg <embe8573@student.uu.se> wrote:
> Emanuel Berg <embe8573@student.uu.se> writes:
>
>> (defun su-edit ()
>>   "Edit the current buffer file as superuser -
>> in a new buffer, that should look the same."
>>   (interactive)
>>   (let ((start-point-pos (point)))
>>     (recenter-top-bottom 0)
>>     (let ((top-window-pos (point))
>>           (buffer (buffer-file-name)) )
>>       (kill-buffer)
>>       (find-file (format "/sudo::%s" buffer))
>>       (goto-char top-window-pos)
>>       (recenter-top-bottom 0)
>>       (goto-char start-point-pos) )))
>
> Aha, now I see, `recenter-top-bottom' doesn't change the point!
> Silly. Still, even though with this realization I could fix it, I
> leave it open to you foxes as you more than once have provided me
> with standard solutions (for which I am grateful, because they
> work better - and not without pride I add that last word :) )

Not sure about "standard solution" (or "fox") but I would do it like this:

  (let ((window-start (window-start))
        (point (point)))
    (find-alternate-file (format "%s~" (buffer-file-name)))
    (goto-char point)
    (set-window-start nil window-start)))