> I believe you're being asked if SunOS 5.x behaves the same way as
> SunOS 4.x...

I don't have access to a SunOS 4 machine, but SunOS 4 is a BSD system,
hence I assume it behaves like NetBSD does today. If someone is willing
ot test, I have a few sample programs.

Aditionnaly, I realize I mixed version numbers for SunOS/Solaris in my
last post. I've checked with SunOS 5.4, (Solaris 2.4), it behaves the
same way as Linux-2.2.18 does, which is no SIGIO generated for pipes,
and no SIGIO to the writer for sockets. SunOS 5.6 (Solaris 2.6) does not
have a F_ASYNC flag, and it introduces a new API for async I/O.

-- 
Emmanuel Dreyfus.  
Hiroshima 45. Tchernobyl 86. Windows 95. 
p99dreyf@criens.u-psud.fr