Mailing-List: contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT sources DOT redhat DOT com
Delivered-To: mailing list cygwin AT sources DOT redhat DOT com
Date: Mon, 16 Jul 2001 17:30:30 +0200
From: Kurt Roeckx <Q AT ping DOT be>
To: cygwin AT cygwin DOT com
Subject: Re: select on the parallel port, and non-blocking io
Message-ID: <20010716173030.A6890@ping.be>
References: <20010716172736 DOT A6856 AT ping DOT be>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Mailer: Mutt 1.0pre2i
In-Reply-To: <20010716172736.A6856@ping.be>

On Mon, Jul 16, 2001 at 05:27:36PM +0200, Kurt Roeckx wrote:
> I use select on 2 fds, one of which is the parallel port.
> 
> The parallel port was opened like this: 
> 
> 	port = open("lpt1", O_RDWR, O_NONBLOCK);
> 
> There shouldn't be any data on the port, since there is no device
> attached, or it's powered down (I tried both).  Yes select() says
> I can read from it, and blocks on it.

Oh, I forgot to mention something.  If I change lpt1 into com1,
things work perfect.  Select() doesn't say there is data to read,
and if I try to read from it, it returns -1, with errno set to
EAGAIN, as expected.


Kurt


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Bug reporting:         http://cygwin.com/bugs.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/