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Re: select on the parallel port, and non-blocking io
- To: cygwin at cygwin dot com
- Subject: Re: select on the parallel port, and non-blocking io
- From: Kurt Roeckx <Q at ping dot be>
- Date: 2001年7月16日 17:30:30 +0200
- References: <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
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