Re: [PATCH] elisp manual patch: add to file notification documentation

[Michael Albinus]

Yoni Rabkin <yoni@rabkins.net> writes:

Hi Yoni,

> I think that there is value in documenting a way for us to check if the
> emacs we are running supports file notification, short of actually
> trying to run `file-notify-add-watch', getting a generic
> `file-notify-error', and reading the associated message to find out if
> it is a simple problem, like a missing directory, or a difficult
> problem, like a missing library.

It's not that simple. Emacs might be compiled with file notification,
but it isn't possible for remote files. Emacs might be compiled without
file notification, but it is still possible for remote files.

And even if it is possible for local or remote files, it might not work
on NFS mounted file systems.

The value of file-notify--library is a vague approximation for being
able to use file notifications. That's the reason for being an internal
constant only.

Calling file-notify-add-watch gives you more precise results.

Best regards, Michael.