Re: sudo in emacs

[Tassilo Horn]

Chris Poole <lists@chrispoole.com> writes:

> On Thu, Jan 5, 2012 at 4:47 PM, Rajanikanth Jammalamadaka
> <rajanikanth@gmail.com> wrote:
>
>> Is there a way I can do this using tramp?
>
> On a file by file basis, I use this:
>
>     (defun find-alternative-file-with-sudo ()
>       "Open the current buffer with privileges given by `sudo'."
>       (interactive)
>       (when buffer-file-name
>         (find-alternate-file
>          (concat "/sudo:root@localhost:"
>            buffer-file-name))))

First of all as an answer to the OP, you can just do

  C-x C-f /sudo:userid@localhost:/foo/bar/baz.txt RET

Because I'm lazy, I have a similar hack in my .emacs:

--8<---------------cut here---------------start------------->8---
(defun th-find-file-sudo (file)
  "Opens FILE with root privileges."
  (interactive "F")
  (set-buffer (find-file (concat "/sudo::" file))))

(defadvice find-file (around th-find-file activate)
  "Open FILENAME using tramp's sudo method if it's read-only."
  (if (and (not (file-writable-p (ad-get-arg 0)))
           (not (file-remote-p (ad-get-arg 0)))
           (y-or-n-p (concat "File "
                             (ad-get-arg 0)
                             " is read-only.  Open it as root? ")))
      (th-find-file-sudo (ad-get-arg 0))
    ad-do-it))
--8<---------------cut here---------------end--------------->8---

So if I try to open a file for which I don't have permissions for, I'm
queried if I want to open it as root using the sudo tramp method.

Bye,
Tassilo