Re: Finding buffers visiting TRAMP sudo files

[Michael Albinus]

"Basil L. Contovounesios" <address@hidden> writes:

Hi Basil,

>> Maybe one could argue that the inode number shall equal
>> for both files, but the device numbers must differ.
>
> Hmm, for me on GNU/Linux the device numbers are indeed
> different but the inode number is always the same:
>
>   (equal (file-attribute-inode-number
>           (file-attributes "/etc/pam.conf"))
>          (file-attribute-inode-number
>           (file-attributes "/sudo::/etc/pam.conf")))
>       ⇒ t
>
>   (equal (file-attribute-device-number
>           (file-attributes "/etc/pam.conf"))
>          (file-attribute-device-number
>           (file-attributes "/sudo::/etc/pam.conf")))
>       ⇒ nil
>
> Is there anything unusual about this?

That's as expected. However, on remote hosts which do not tell us inode
numbers, Tramp generates virtual ones. Think about "smb", for example.

> By "comparing" e.g. "/etc/pam.conf" and
> "/sudo::/etc/pam.conf" I mean determining whether they
> ultimately name the same file, as per file-equal-p.

Tramp has no information about how different methods and hosts are
related. Even "/ssh::.emacs" and "/scp::.emacs" live on different
filesystems for Tramp.

One could implement such a relation for local files and remote files on
the local host, using Tramp's `tramp-local-host-p' function. This would
require an extension to Tramp's implementation of `file-equal-p'.

Hmm, I'm kind of undecided whether it's worth to do.

> Kind regards,

Best regards, Michael.