Re: [babel] using tramp when tangling

[vanicat@debian.org (Rémi Vanicat)]

Maurizio Vitale <mav@cuma.i-did-not-set--mail-host-address--so-tickle-me> writes:

> I'd find useful to use tramp syntax in the :tangle specification.
> In my case it would be to specify sudo when tangling config files that
> are supposed to go to areas not writable by the user running Emacs. 
> Something like:
>
> #+begin_src sh :tangle /sudo::/etc/my_config_file
> ...
> #+end_src
>
> other people might be interested in remote access to tangle targets.
>
> Is there a way to achieve the above?
>
> If I try to tangle the above, I get something along the lines that
> "tramp cannot append to file". Would it be possible to have org-babel to
> (optionally) tangle to a buffer and then save to file in one go?

It's a bug of append-file. We could not use it: (code by Alexey Voinov,
stolen from magit):

--8<---------------cut here---------------start------------->8---
diff --git a/contrib/babel/lisp/org-babel-tangle.el b/contrib/babel/lisp/org-babel-tangle.el
index dd76195..c4ea0d8 100644
--- a/contrib/babel/lisp/org-babel-tangle.el
+++ b/contrib/babel/lisp/org-babel-tangle.el
@@ -127,7 +127,12 @@ exported source code blocks by language."
                         (insert (concat she-bang "\n"))
                         (setq she-banged (cons file-name she-banged)))
                       (org-babel-spec-to-string spec)
-                      (append-to-file nil nil file-name))
+		      (let ((content (buffer-string)))
+			(with-temp-buffer
+			  (insert-file-contents file-name)
+			  (goto-char (point-max))
+			  (insert content)
+			  (write-region nil nil ignore-file))))
                     ;; update counter
                     (setq block-counter (+ 1 block-counter))
                     (add-to-list 'path-collector file-name)))))
--8<---------------cut here---------------end--------------->8---


-- 
Rémi Vanicat