[BRLTTY] can't read screen content

[Aura Kelloniemi]

Hi list,

On 2026-05-22 at 09:53 +0200, Samuel Thibault <samuel.thibault at ens-lyon.org> wrote:
 > Sébastien Hinderer, le ven. 22 mai 2026 07:19:59 +0200, a ecrit:
 > > By the way: am I correct that BRLTTY has no way to know dynamically
 > > whether the console is in UTF-8 mode or not?

 > It is IUTF8 in the termios c_iflags, but that should only be relevant
 > for console input, not for output, that shouldn't be changing the way
 > /dev/vcsa reports characters, so that's most probably just a bug in the
 > kernel.

I would think this is so that /dev/vcsa works all the time (because switching
BRLTTY's vcsu support off makes it work), but /dev/vcsu devices stop working
once the terminal is in non-UTF-8 mode.

It is hard to imagine, what /dev/vcsu devices should present, when the console
contents are not Unicode at all. So maybe BRLTTY should switch to using
/dev/vcsa devices, if /dev/vcsu is not available. However, the problem still
remains:how could BRLTTY know which character set is used by the console, if
it is not UTF-8.

-- 
Aura