On Tuesday, January 25, 2011 13:21:14 Arnd Bergmann wrote:
> On Tuesday 25 January 2011 18:45:15 Roland McGrath wrote:
> >  I know of no reason to
> > 
> > think that the current treatment of the empty string was ever intended at
> > the creation of the *at interfaces.
> 
> I always assumed that this was done so that the *at syscalls can replace
> both the ones that take a file descriptor (e.g. fstat) and the ones that
> take a pathname (e.g. stat), which is sensible for the non-AT_FDCWD case,
> although not documented in the man pages.
> 
> Treating the empty string special for AT_FDCWD is rather pointless, but
> at least consistent.

i dont know if the gnulib peeps are on these lists, but i think their 
implementations of some of the *at funcs leverage the extended behavior that 
is available under Linux.  or at least, i'm certain they'll have some insight 
into some of these nuances.
-mike