Re: Add five new escape sequences to wscons

[David Brownlee <abs%absd.org@localhost>]

On Mon, 16 Jan 2023 at 17:20, Valery Ushakov <uwe%stderr.spb.ru@localhost> wrote:
>
> On Mon, Jan 16, 2023 at 09:18:53 -0300, Crystal Kolipe wrote:
>
> > It's useful, because these sequences correspond to the terminfo
> > capabilities rin, indn, vpa, hpa, and cbt as defined in the xterm
> > terminfo entry.  With these sequences implemented, it becomes
> > slightly more practical to set TERM=xterm when connecting to remote
> > systems that don't have a comprehensive terminfo database.
>
> Why is is desirable to set specifically TERM=xterm instead of, say,
> vt220, or whichever vt entry describes wscons the closest?
>
> For multi-line scroll the patch just calls scrollup/scrolldown, but
> that's not what the single-line scroll commands do (see
> wsemul_vt100.c)
>
> I'm actually not entirely convinced that it's even correct to describe
> vt220 as having sf/ind scrolling capabilities, b/c the vt220 scrolling
> sequences take the scrolling region into account and the terminfo
> capabilities for scrolling are defined to operate on the whole screen
> as far as I can tell.
>
> So in its current form I don't think this patch is suitable and I'm
> not convinced it's needed at all.

Technically the wscons terminal type is wsvt25, an extended ANSI
compatible terminal, already supporting more sequences than vt100.

Having it also support a useful subset of xterm, providing it doesn't
add an excessive amount of complexity, seems like a useful addition,
particularly if other systems also have a "wscons" with similar
additional handling.

Double checking some of the new capabilities may well be a good idea,
plus noting in comments that they exactly match xterm behaviour, and a
short note in the wscons manpage - I don't have enough ANSI/terminfo
context to add anything directly useful on that point.

Thanks

David