Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!seismo!sundc!newstop!sun!snafu!lm
From: lm@snafu.Sun.COM (Larry McVoy)
Newsgroups: comp.unix.wizards
Subject: Re: sockets and select
Keywords: socket select
Message-ID: <132218@sun.Eng.Sun.COM>
Date: 24 Feb 90 20:19:37 GMT
References: <4309@helios.TAMU.EDU>
Sender: news@sun.Eng.Sun.COM
Reply-To: lm@sun.UUCP (Larry McVoy)
Distribution: usa
Organization: Sun Microsystems, Mountain View
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In article <4309@helios.TAMU.EDU> dhess@cs.tamu.edu (David K Hess) writes:
>	When I perform select() calls for reading only, strange
>things happen. At first the call works correctly and I empty the
>socket and do another select.  Then after a while, when I perform a
>recv() on the "selected" socket I get 0 bytes.  Yet when I select
>again I get the same socket ready for reading.  Pretty soon they are
>all doing it and select() has become as useful as polling.

This sounds like you are getting EOF on the socket.  If my memory serves
me correctly, if one does a select() to see if a socket is ready for reading
and the select says "yes" but a read says "0 bytes," that means that the 
other end of the connection went away.  I could be wrong - this is based
on socket hacking I did about 4 years ago under 4.2 (4.3?) BSD on a vax.
---
What I say is my opinion.  I am not paid to speak for Sun, I'm paid to hack.
    Besides, I frequently read news when I'm drjhgunghc, err, um, drunk.
Larry McVoy, Sun Microsystems     (415) 336-7627       ...!sun!lm or lm@sun.com