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To: cygwin AT cygwin DOT com
Subject: Why does fhandler_tty_slave::open call attach_tty?
From: Jon Cast <jcast AT ou DOT edu>
Reply-to: cygwin AT cygwin DOT com
Date: Tue, 09 Oct 2001 00:32:34 -0500


cgf told me to submit patches here, since I'm not planning on becoming
a major contributor to Cygwin.  However, I'm not sure if this is the
correct place to submit questions about the Cygwin code to.  Hoping it
is, here's my question.

fhandler_tty_slave::open begins with the following code:

-- 461 --
>  tcinit (cygwin_shared->tty[ttynum]);
>
>  attach_tty (ttynum);
>  tc->set_ctty (ttynum, flags);

attach_tty just calls tty_list::connect_tty, which in turn just
verifies the tty number and returns it if it's meaningful.

However, that return code isn't used by fhandler_tty_slave::open.
What is attach_tty supposed to do, and why is it called here?

Also, what does tty_min::set_ctty do?  I have a feeling one or both of
these is intended to set the controlling tty of the process.  If so,
what is the recommended way to get around this code in
fhandler_tty_slave::open (as openpty needs to do)?

Finally, are there any design documents I'm missing?

Jon Cast

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