Problem generating SIGIO on SLC

[Mark]

I am using a SPARCstation SLC running 4.1.  I have written a program which
opens a socket(), tries to configure it to send SIGIO when input is
available, and then goes off on its way.  However, it never receives
SIGIO.  There are three ways to configure a socket for SIGIO in SunOS 4.1
and I have tried them all:

	pid = getpid();
1.	fcntl(sock, F_SETOWN, pid);
2.	ioctl(sock, FIOSETOWN, &pid);
3.	ioctl(sock, SIOCSPGRP, &pid);

I am running the csh, so the process ID == the process group ID.

Has anyone ever done this successfully?  Can anyone tell me "You idiot!
You forgot to ..."

Thanks in advance,
Mark Logan  uunet!lcc!turnkey!crystel!logan