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From: zessel@tsetse.informatik.uni-kl.de (Holger Zessel)
Newsgroups: comp.unix.wizards
Subject: Re: HELP! BSD select() on socket (WIN/TCP for VMS)
Message-ID: <3895@incas.informatik.uni-kl.de>
Date: 20 Mar 90 10:23:43 GMT
References: <22789@adm.BRL.MIL>
Sender: news@incas.informatik.uni-kl.de
Lines: 27

TAYBENGH%NUSDISCS.BITNET@cunyvm.cuny.edu writes:

 >select() takes in NULL pointer for writefds/exceptfds, but I always encounter
 >access violation run-time error when I tried to call

 >        select(n, readfds, 0, 0, &timeout);
You may have forgotten the & in front of readfds ?

 >Moreover, select() supposed to block or return depend on the timeval (timeout)
 >passed in, but it always return immediately no matter what timeout value I
 >gives without setting any fle descriptors (channels). For example,

 >        if (nfd = (select(sock+1, &ready, &write, &except, &timeout)) <0)
 >           perror("select");
Just take a very sharp look at the code and especially the parentheses.
 < has a higher priority than =
->
       if ((nfd = select(sock+1, &ready, &write, &except, &timeout)) <0)
          perror("select");

 >-Beng Hang (taybengh@nusdiscs.bitnet)
----------------------------------------------------------------
Holger Zessel, uucp: ...!uunet!unido!uklirb!incas!zessel
	or	zessel@informatik.uni-kl.de
	or	zessel%informatik.uni-kl.de@relay.cs.net (from usa)
Fachbereich Informatik, SFB124-D1
Universitaet Kaiserslautern, West-Germany