Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Date: Tue, 27 Apr 2004 11:50:28 -0500
From: Brian Ford <ford AT vss DOT fsi DOT com>
Reply-To: cygwin AT cygwin DOT com
To: Jim Brain <brain AT jbrain DOT com>
cc: cygwin AT cygwin DOT com
Subject: Re: Need to replicate TIOCGICOUNT and TIOCMIWAIT on cygwin
In-Reply-To: <loom.20040427T075714-582@post.gmane.org>
Message-ID: <Pine.CYG.4.58.0404271140220.5560@fordpc.vss.fsi.com>
References: <loom DOT 20040427T053617-292 AT post DOT gmane DOT org> <loom DOT 20040427T075714-582 AT post DOT gmane DOT org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Tue, 27 Apr 2004, Jim Brain wrote:

> As a followup, I thought maybe I would use the Win32 API to open a
> serial port, use cygwin_attach_handle_to_fd() and save off both handles.
> Then, when I need to WaitCommEvent, I'd use the HANDLE, otherwise, use
> the fd.

cygwin_attach_handle_to_fd currently has little to no error checking.
I'll see if I can make a patch to fix that if I have time.
You could too if you are so inclined.

> Problem:
>
> All the examples online use CreateFile, which I coded up, and cygwin
> gives me a fd of 8, but select returns immediately and I read -1 bytes
> on serial.  I looked at the cygwin source, which uses NtCreateFile, but
> I can't find headers or libraries for that. I am stumped.  I feel like I
> am so close...  It's rather a bummer there is a not a
> cygwin_get_win32_handle(int fd), as that is what I need.

http://cygwin.com/acronyms/#PTC

> Anyone got any ideas?

You didn't say what version of Cygwin you are using.  Please see
http://cygwin.com/problems.html for the details we need.

AFAIK, the NtCreateFile change is a very recent one, only available in
fairly recent snapshots.  It has a bug in that it doesn't support win32
device paths and thus the internally defined path to the COM ports.
Hopefully, that will be fixed soon.

This is temporarily a bad time to be working on COM port stuff :-(.

-- 
Brian Ford
Senior Realtime Software Engineer
VITAL - Visual Simulation Systems
FlightSafety International
the best safety device in any aircraft is a well-trained pilot...

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/