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From: icarus@End.Tufts.EDU ("Michael J. Saletnik - Local Unix Wizard's Apprentice")
Newsgroups: comp.protocols.tcp-ip
Subject: Programming question
Message-ID: <9010301840.AA04727@sol.end.tufts.edu>
Date: 30 Oct 90 18:40:50 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 36

Hi.  I've got a question for all the experienced TCP/IP programmers out there.
I've been trying to find this in the manuals, but I can't anywhere.
I'd greatly appreciate confirmation of my technique and answers to the
random questions..
In any case:
System: Sun 3/50,3/180
OS: SunOS 4.1

Given a bound and listening socket, can I use
	fcntl(socket, F_SETFL, FNDELAY);
to cause it to be non-blocking, and that way when
I call accept() I'll either get back a new socket
for a new connection, or errno = EWOULDBLOCK
And when do I make the fcntl() call?

Given a newly connected socket from an accept(),
do I use
	fcntl(socket, F_SETFL, FASYNC);
to enable SIGIO signals, and
	fcntl(socket, F_SETOWN, getpid());
to point those signals at my process, and
	signal(SIGIO, handler);
to establish my handler?  What order should these
be?

Finally, if my signal handler is declared
	handler(sig, code, scp, addr)
	int sig, code;
	struct sigcontext *scp;
	char *addr;
how can I find out which socket (or file descriptor)
caused that signal?

	Thanks in advance,
				Michael J. Saletnik
				icarus@end.tufts.edu