Re: What's the locale for system files (e.g. /etc/fstab)?

On Thu, Mar 24, 2022, 10:30 AM Simon J. Gerraty <sjg@juniper.net> wrote:

> Warner Losh <imp@bsdimp.com> wrote:
> > Config files, like fstab, have no locale and parsing them with a locale
> leads to errors, even when the user or the system has a nondefault locale.
> >
> > >
> > > Put more generally, there's not a system-wide place which declares the
> > > encoding for system files, which leads to this problem where we
> > > interpret files from one user's locale using another user's locale.
> >
> > Well /etc/login.conf *IS* a system wide declaration of this type of
> > stuff, both lang= and charset= are declared there.
> >
> > Since system wide files like yhese are always parsed without a locale,
> this information is correct, but I'm not sure how it applies.
> >
> > It is always  C.UTF-8. Anything else may, or may not, work based on
> accidents of coincident encoding. Not everything can change locales, and
> the fstab and other parsing routines in libc assume C.UTF-8 or even just
> the ascii-7/8 subset.
> >
> > >
> > > One solution would a symlink in /etc that "points to" the name of the
> > > current system-wide locale name.
> > >
> > > % ls -Fl /etc/locale
> > > lrwxr-xr-x  1 root  wheel  7 Mar 23 15:42 /etc/locale@ -> C.UTF-8
> >
> > grep lang /etc/login.conf:
> >         :lang=C.UTF-8:
> >         :lang=ru_RU.UTF-8:\
> >
> > Probably what you want?
>
> I doubt it, one is from the entry for Russian users ;-)
>
> >
> > You can get this with the locale routines, no? No need for grep.
>
> I suspect not.
>
> AFAIK virtually everything about locale support tells you about the
> locale for the current process - which does not necessarily inform you
> of the locale that was in effect when a system file was last edited.
>
> I don't even know if it is guaranteed that everything that reads system
> files groks random locales - or what happens when you have 3 admins each
> prefering a different locale, do different entries in fstab for example
> get impacted and the result thus not readable by anyone?
>
> There's probably something to be said for enforcing something like
> C.UTF-8 for system files.
>

That is the primary reason for system files always being C.UTF-8... There
is no way to tag it as anything else... and some of these files are often
parsed from a context that can't set the locale, like the boot loader or
the kernel... also, these files have a format that was defined back in the
7bit ascii time frame. They also don't make use of the text in a way that
isn't literal...

Having said that, I'm unsure how you'd mount /<kanji-for-neko> from fstab,
or if that is well defined. The kernel just presents a string of bytes not
containing /...

Warner

--sjg
>