SIGIO interrupts with stream sockets

[David George]

I'm running HP-UX A.B3.00 B 9000/835 and communicating between processes
using stream-type sockets.  At a given process, I'd like to automatically
generate a SIGIO interrupt each time thet messages arrive on a given socket.

The HP man pages describe a method using ioctl with FIOSSAIOOWN and
FIOSSAIOSTAT -- see termio(7) for details -- but that method doesn't seem 
to work on sockets.  A 4.3BSD Berkeley Tutorial describes a similar method
using fcntl with F_SETOWN and F_SETFL, but F_SETOWN isn't defined anywhere
in my /usr/include directory.

Does anyone know the correct way to do this under HP-UX?  Thanks for your help.

Dave George