Berkely unix (4.2) tty ioctl question

[Warren Montgomery]

I have an application where I want to change the "local characters"
associated with a tty synchronously with output.  (i.e., wait until
the output queue is empty, and then make the change).  I have asked
several local experts, and alas nobody has a way of doing it.  There
seems to be no direct way (i.e. no ioctl that does just this), and
no indirect way (no ioctl that just waits until output becomes
quiescent and nothing else).  This is such an obvious thing to want
to do, I can't believe that it is really impossible.  For people
familiar with the AT&T unix tty system, what I want is the
equivalent of the TCSETAW ioctl.

Does anybody have any hints on how to do this?  Is there any way
just to wait until the output queue is empty and then issue the
proper ioctl?  If there is something that works for 4.2, does it
work in any of the other berkeley variants?

Thanks for any advice you can give.

-- 

	Warren Montgomery
	ihnss!warren
	IH (8-367) x2494