write-as or "clone file"

[anarcat]

One thing I'm frequently fighting with in Emacs (because it allows me to do crazy things like that) is how to synchronize file copies sent through TRAMP and local copies.

As a concrete example, I was doing a small hotfix on a Python library today, in /usr/lib/python3/dist-pacakges/npm2deb/mapper.py. The git source is in ~/src/npm2deb/npm2deb/mapper.py so I naturally started writing there. But then to test my changes, instead of rebuilding and reinstalling the whole thing, I cheat and write directly to the system lib with TRAMP (/:sudo:/usr/lib/python3/dist-pacakges/npm2deb/mapper.py or whatever that magic sauce is). Then I can tweak things there ("we'll do it live!") but what often happens is I forget to sync the file back into ~/src.

If there was a quick way to write a copy of the file without changing the buffer association, this would be much easier and intuitive. This SO thread has a few implementations, for example:

(defun my-clone-and-open-file (filename)
  "Clone the current buffer writing it into FILENAME and open it"
  (interactive "FClone to file: ")
  (save-restriction
    (widen)
    (write-region (point-min) (point-max) filename nil nil nil 'confirm))
  (find-file filename))

I would personally prefer that approach of keeping the other buffer in the background:

(defun crux-clone-file (filename)
  "Clone the current buffer writing it into FILENAME and open it in another buffer"
  (interactive "FClone to file: ")
  (save-restriction
    (widen)
    (write-region (point-min) (point-max) filename nil nil nil 'confirm))
  (find-file-no-select filename))

Obviously, for my use case, this would need to be added in a after-save-hook.

Would that make sense? would this be accepted as a PR?

Thanks!

[jimmywongroo]

#55 Doesn't work for you?

[anarcat]

ah yes, that should probably do it, thanks! :)