select on the parallel port, and non-blocking io
Kurt Roeckx
Q@ping.be
Mon Jul 16 08:30:00 GMT 2001
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/
More information about the Cygwin
mailing list