Visudo/sudoedit and gvim –remote-silent

sudoedit allows you to edit a file with an editor running on your own user id. It copies the file to a temporary file which your editor can then write into. As soon as the editor is closed, the edited file is copied back.

There is no built-in possibility to automatically write changes back while the editor is still running.

So you need either

• run the editor on the other user id (e.g. sudo vi /file/to/edit )
• copy the file manually back in a (separate) shell (sudo cp /tmp/... /file/to/edit) or from inside vim :!sudo cp % /file/to/edit. From vim you can also start a shell with :sh or put vim in the background with Ctrl+Z and restore it with fg.
• use https://stackoverflow.com/questions/2600783/how-does-the-vim-write-with-sudo-trick-work
• create your own version of sudoedit which writes changes back as soon as the temporary files is changed. This should be easily doable with some scripting. Inotify can help you to detect changes (see for example Can a bash script be hooked to a file? )

The point of sudoedit is to allow users to edit files they wouldn’t otherwise be allowed to, while running an unprivileged editor. To make this happen, sudoedit copies the file to be edited to a temporary location, makes it writable by the requesting user, and opens it in the configured editor. That’s why the editor shows an unrelated filename in a temporary directory. When the editor exits, sudoedit checks whether any changes were really made, and copies the changed temporary file back to its original location if necessary.