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Date: Wed, 27 Sep 2006 22:13:36 -0400
From: Christopher Faylor <cgf-no-personal-reply-please AT cygwin DOT com>
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Subject: Re: tcgetattr problem
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On Thu, Sep 28, 2006 at 12:10:18AM +0100, 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.

"It looks like a file to Cygwin"

>I also note that read() and write() work ok too using "com1", but
>tcsetattr() also fails.

"It looks like a file to Cygwin"

>BTW, I obtained the CVS source, but couldn't find the _ioctl() call 
>anywhere in my (brief) grepping. Is there any documentation about internal
>structure, and whats going on under the hood?

The name of the function is "ioctl", not "ioctl".

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