Access value of output-directory

Hi,

am I right that there is no way to access the value of the
'-output-directory' command line option from within pdfTeX?
If true, I think it would be very convenient for package authors
if you could provide a new primitive to do so.

I understand that one can access the argument vector from within
LuaTeX, but I think a lot of authors would rather not make their
packages LuaTeX-only (at least for now).

Regards,
Johannes