Re: terminfo change for screen/eterm?

[Timothy Allen]

On 2/1/23 22:51, G. Branden Robinson wrote:
> As I recall, ^? is also what actual DEC VT-series terminals emit when
> the key-that-is-in-the-backspace location is pressed.  (Unfortunately,
> my VT520 and 525 have been in storage for years.)
>
> But--and Thomas can surely correct me here--I think X Consortium or even
> MIT Athena xterm (the program goes back to 1984, before X itself), while
> otherwise emulating a VT100 (or thereabouts), deliberately used ^H for
> this key instead.

On the VT100, the key above Enter sends ^H.

On the VT220 and above, the key above Enter sends ^?, but there's a 
config setting to default to ^H, and it can be changed during a session 
by sending an escape sequence.

When Linus wrote the Linux console terminal driver, he made it follow 
the behaviour of the VT220 he was familiar with, including 
backspace-as-^?. Following from that precedent, Debian patches all their 
terminal apps and terminal emulators to default to backspace-as-^?, so 
that at least within that ecosystem, everything Just Works.

In the same way that terminfo's `lines` and `cols` capabilities have 
been superseded by TIOCGWINSZ, since modern terminals can be resized, I 
think terminfo's `kbs` capability should be superseded by checking the 
value in `stty erase`, for the same reason: modern terminals can change 
it dynamically.


Tim.