Re: Not A System Problem [LWN.net]

Re: Not A System Problem

Posted Mar 29, 2009 13:54 UTC (Sun) by nix (subscriber, #2304)
In reply to: Re: Not A System Problem by ldo
Parent article: Wheeler: Fixing Unix/Linux/POSIX Filenames

What you're describing is not POSIX anymore. Every single POSIX app would
need rewriting, for essentially zero gain (ooh, you can't have nulls in
filenames: that's why UTF-8 is *defined* to avoid nulls in filenames).

I'm sure users would love not being able to type in pathnames anymore,
too.

Good luck getting anyone to do it.

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Re: Not A System Problem

Posted Mar 29, 2009 19:47 UTC (Sun) by ldo (subscriber, #40946) [Link]

nix wrote:

What you're describing is not POSIX anymore.

Nothing to do with POSIX. POSIX is a userland API, it doesnt dictate how the kernel should work.

Re: Not A System Problem

Posted Mar 29, 2009 22:32 UTC (Sun) by nix (subscriber, #2304) [Link]

You don't get it. In order to permit / and \0 as valid filename
characters, syscalls like open() must change. Library calls like fopen()
have to change, because they too accept a \0-terminated string, with /s
separating path components. Every single call in every library that
accepts pathnames has to change. Probably the very notion of a string has
to change to something non-\0-terminated.

So whatever you're describing, userspace cannot any longer use standard
POSIX calls: in fact, it can't any longer use ANSI C calls! I suspect that
such a system would be almost unusable with C, simply because you couldn't
use C string literals for anything.

If you want VMS, you know where to find it.