[BRLTTY] Low-level BrlAPI questions

[Aura Kelloniemi]

On 2021-04-16 at 12:13 +0200, Samuel Thibault <samuel.thibault at ens-lyon.org> wrote:
 > Aura Kelloniemi, le ven. 16 avril 2021 12:33:31 +0300, a ecrit:
 > > I read that it is possible to use enterTtyMode even when the client is already
 > > controlling a TTY.

 > ? Where did you read that? I believe that's not possible

In the BrlAPI reference manual, specifically here:
https://mielke.cc/brltty/doc/Manual-BrlAPI/English/BrlAPI-7.html#ss7.3

See the first packet type in the TTY handling mode list.

 >       /* uhu, we already got a tty, but not this one: this is forbidden. */
 >       WERR(c->fd, BRLAPI_ERROR_INVALID_PARAMETER, "already having a tty");

I suggest that this behaviour is just documented in the reference manual,
because the semantics are much clearer the way it is implemented than how it
is documented.

-- 
Aura