winsize / openpty specification

 Hi,
 Can anyone tell me which is the "official" openpty(3) specification,
if there is one ? It's not SUSv3. The headers to include are not the
same on Linux, Open/FreeBSD, Tru64. Where is "struct winsize"
supposed to be defined ? What is the openpty(3) portability level ?
I guess it's not really portable, since Dan didn't use it in his
ptyget package, but I think doing without openpty is even more of a
portability nightmare (think ioctl)...

 Thanks,

-- 
 Ska