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Re: file-equal-p
From: |
tomas |
Subject: |
Re: file-equal-p |
Date: |
Fri, 17 Feb 2023 13:45:57 +0100 |
On Fri, Feb 17, 2023 at 02:25:38PM +0200, Eli Zaretskii wrote:
> > From: Andreas Schwab <schwab@linux-m68k.org>
> > Cc: Po Lu <luangruo@yahoo.com>, emacs-devel@gnu.org
> > Date: Fri, 17 Feb 2023 11:02:48 +0100
> >
> > On Feb 16 2023, Richard Stallman wrote:
> >
> > > If so, can Emacs examine it using that other way?
> >
> > The right way to solve the issue is to only compare the inode and device
> > numbers. The other attributes (other than the type) can change any time
> > for unrelated reasons, and do not define the identity of a file.
>
> That depends on the semantics of "files are equal". If the issue is
> only whether two file names point to the same file's data, then yes,
> using file-attribute-file-identifier is TRT.
This is how I read `file-equal-p''s docstring [1] (coming from Lisp,
I'd called it `file-eq-p', but hey :-)
> But that is not the only
> possible semantics of these tests. It is therefore up to the
> application to decide which API to use, IMO.
>
> Of course, as long as the file is identified only by its name, race
> condition is possible even if we only compare the inode and the device
> number.
Identity is always difficult in a mutable world, yes.
Cheers
[1] Return non-nil if files FILE1 and FILE2 name the same file.
--
t
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- Re: file-equal-p, (continued)
- Re: file-equal-p, Andreas Schwab, 2023/02/16
- Re: file-equal-p, Po Lu, 2023/02/16
- Re: file-equal-p, Michael Albinus, 2023/02/16
- Re: file-equal-p, Po Lu, 2023/02/16
- Re: file-equal-p, Eli Zaretskii, 2023/02/16
Re: file-equal-p, Richard Stallman, 2023/02/16