how to customize readtags path for a remote machine?

[askeySnip]

the question is when I use tramp for remote dev, it use the remote readtags or the local readtags? and how can I config the readtags located in remote machine for citre to use?
thanks!

[AmaiKinono]

Actually I don't have a remote machine so I can't answer this question. I test TRAMP using local files.

To the best of my knowledge, TRAMP uses remote programs when visiting remote files.

[askeySnip]

Actually I don't have a remote machine so I can't answer this question. I test TRAMP using local files.

To the best of my knowledge, TRAMP uses remote programs when visiting remote files.

You are right. So I want to know how to config different path?
The temp solution is using source to add the remote different readtags path into PATH.
Thanks for your reply.

[AmaiKinono]

What about this:

(defun set-remote-ctags-env ()
  "Set readtags path according to host name."
  (when-let* ((remote-host (file-remote-p (buffer-file-name) 'host)))
    (setq-local citre-readtags-program
                (pcase remote-host
                  ;; Put your pair of hostname and readtags path here
                  ("remote-host-1" "readtags-program-path-1")
                  ("remote-host-2" "readtags-program-path-2")))))

(add-hook 'find-file-hook #'set-remote-ctags-env)

[fuzy112]

citre-readtags-program is defined as (set file (const nil)) in citre-core.el, but it is used as a string, so if you customize this variable using Easy Customization, an error will occur when running citre commands.

citre/citre-core.el

Lines 58 to 65 in 1c0ca63

	(defcustom citre-readtags-program nil
	"The name or path of the readtags program.
	Set this if readtags is not in your PATH, or its name is not
	\"readtags\".
	Citre requires the readtags program provided by Universal Ctags."
	:type '(set file (const nil)))

[Ergus]

Hi:

Related to this, the oficial emacs solution for these problems is to use connection-local-variables.

https://www.gnu.org/software/emacs/manual/html_node/elisp/Connection-Local-Variables.html

I made the gtags-mode implementation for emacs with full tramp support and I use them to enable full remote executable detection and some memoization (to avoid the impact of calling executable-find more than needed) but at the same time it checks when gtags is not available remotely to avoid nasty errors

https://github.com/Ergus/gtags-mode

Just my 5 cents

[AmaiKinono]

@Ergus Thanks very much, and sorry for the late response.

I think I understand the overall approach, but I have trouble understanding your implementation. To me it seems like all the things we should do is wrapping the codes that start a process in with-connection-local-variables.

Also, as I don't have a remote machine, I cannot test the code or write a user document explaining how to customize executable paths on remote machines.

What we need is a TRAMP user to help use write the code and documentation.