Subject: bug#73709: 29.4; Doc of `file-newer-than-file-p'

From: Stefan Kangas <[email-masked]>
Date: Wed, 9 Oct 2024 23:42:30 +0000

Eli Zaretskii <[email-masked]> writes:

> Are you sure this is a good idea?  If the user who reads the doc
> string doesn't know the meaning of "the file is newer", how can we be
> sure she knows the meaning of "file's last modification time"?

On GNU/Linux (actually POSIX) systems, we have atime/ctime/mtime.

The word "newer" does not make it clear if we mean ctime or mtime.

The phrasing "last modification time" makes it clear that we're talking
about mtime.  This phrase is already used further down in (info "(elisp)
File Attributes"), and should be equally good here.

>                                                                 What
> is "last modification"? does changing the file's mode bits constitute
> "modification"? does renaming the file or moving it to another
> directory constitute "modification"? what is the meaning of "last
> modification time" of a directory? etc. etc. -- do we have now to
> explain all of that in our documentation?

I don't see a need for the Elisp manual to explain these details.

Users that need to know such things in detail will have to refer to
other platform-relevant documentation, such as the POSIX standard:

https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap04.html#tag_04_12