tcgetattr problem

Wed Sep 27 23:12:00 GMT 2006

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.

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?


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