Re: [Bug-tar] mac os x or general charset problem patch

[Paul Eggert]

Heiko Voigt <address@hidden> writes:

> As I read from the standard a POSIX system only has to support the portable
> characterset.

This has been a point of issue in the Open Group.  Read one way, for
example, the file name "a/-b/c" is not portable and need not be
supported.  But many people in the Open Group would say that (aside
from length limits) every nonempty string of nonnull bytes is a valid
file name.

> It says: "The encoded values associated with the members of the portable
> character set are each represented in a single byte. Moreover, if the value is
> stored in an object of C-language type char, it is guaranteed to be positive
> (except the NUL, which is always zero)."

That's the requirement for portable characters.  The requirement for
portable file names is much stricter.  See
<http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap04.html#tag_04_06>.

However, as I mentioned, this is a messy area in the spec.  It's not
clear that a POSIX implementation can refuse to create a file named
"abc~", for example, simply because it doesn't like the "~".
Certainly many applications would break on a system that didn't allow
such file names.

As far as 'tar' goes, I would say that by default tar should create
the files with the names taken from the tar image, and should back off
to mangled names only on user request.