Re: coreutils-6.0 on platforms without fchdir

[Bruno Haible]

Paul Eggert wrote:
> On platforms lacking fchdir,
> put a wrapper around 'open' so that we can keep track of which file
> descriptors correspond to directories.  The 'open' wrapper puts the
> name of the opened directory into a hash table.  (The name must be
> absolute, so 'open' may need to do the equivalent of pwd.  This could
> be further optimized by wrapping 'chdir' and 'close', though I'm not
> sure it's worth the trouble.  We  might also get away with using
> O_DIRECTORY to decide whether to put an entry in the hash table.)

That's an interesting idea. Actually, I think a hash table would not
be necessary; a linear table, indexed by the file descriptor, would be
enough.

Jim Meyering wrote:
> A fundamental goal in coreutils development has been to code to the most
> modern/useful/portable interfaces.  Anything else should be hidden as far
> under the covers as possible.  That's one of the reasons there are so
> many replacement functions in coreutils and gnulib and so few #ifdefs
> in coreutils/src/*.c.

I agree it's a good choice to do it this way.

> And since BeOS seems to be a fringe
> system (i.e., nearly museum-only), no one will notice the performance hit.

It's not only BeOS, it's also mingw and djgpp which lack an fchdir().

Bruno