X-Spam-Check-By: sourceware.org Message-ID: <451B0662.5020608@cygwin.com> Date: Wed, 27 Sep 2006 19:16:50 -0400 From: "Larry Hall (Cygwin)" Reply-To: cygwin@cygwin.com User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.5) Gecko/20060727 Fedora/1.5.0.5-1.fc4.remi Thunderbird/1.5.0.5 Mnenhy/0.7.4.0 MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: tcgetattr problem References: <20060927193049.GA29552@flixx.linux.bogus> <20060927231017.GC29552@flixx.linux.bogus> In-Reply-To: <20060927231017.GC29552@flixx.linux.bogus> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com On 09/27/2006, ahnkle wrote: > On 18:36 Wed 27 Sep , Igor Peshansky wrote: > > > > > > #define PORT "com1" > > > ... > > > fd = open(PORT, O_RDWR | O_NOCTTY ); > > > > > > There's your problem. When you open a port as "com1", it looks like a > > > file to Cygwin, since it doesn't recognize it as a valid device name. > > > Thus any attempt to manipulate that fd as a device will fail. > > > > > > Use the Cygwin device (e.g., "/dev/ttyS0"). > > Strangely, com1 *does* work in the call to open. Having tried "/dev/ttyS0", > tcgetattr() works ok. > > I also note that read() and write() work ok too using "com1", but > tcsetattr() also fails. "/dev/ttyS0" is an emulated device in Cygwin. "com1" is a DOS/Windows device. If you want POSIX behavior from a device, use the Cygwin emulated device. Otherwise, you're stuck with DOS/Windows devices and their semantics. That's why "/dev/ttyS0" exists. There's no magic here. And there certainly isn't any bug. -- Larry Hall http://www.rfk.com RFK Partners, Inc. (508) 893-9779 - RFK Office 216 Dalton Rd. (508) 893-9889 - FAX Holliston, MA 01746 -- 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/