OSC 50 (get/set font) VT sequence

As per ctlseqs.txt from xterm, OSC 50 is used to query/set the use font.

I was actually looking into neofetch and how it is detecting the font being used, and I think they all got it wrong (fishing the font by looking into the config file of the detected terminal). The proper way to communicate with the TE is to use the PTY, so through some VT sequence.

There is already OSC 50 and at least xterm and mintty (and mine) are supporting that. I’d wonder if you have interest in supporting that too (at least the getter part).

Many thanks, Christian.

[mintty]

get/set default font (OSC 50?)

This sequence refers to the currently selected font attribute in mintty. So SGR 12 OSC 50 SGR 10 would change alternative font 2 etc. Also works separately in Tek mode.

list fonts usable as default (aka installed fonts for the TE)

Mintty has a command-line option to report (monospace) fonts: mintty -Rf. I don’t think it’s too useful to retrieve the (long) list interactively.

upload a new font (old VTs had sequences for that)

This feature of historic VT terminals was applicable and defined for bitmap fonts. So it’s not really too useful nowadays and I would discourage any terminal to spend effort on it; there are no plans to ever implement it in mintty.

register a font to an SGR slot 11-19

Actually SGR 11-20, where 11 and 20 are slightly special cases.

[jerch]

Oh sorry, I mixed the TE names - I actually meant mintty, thats the TE which is far ahead in terms of font settings, not mlterm. I think the core maintainer is active on github under the same name.

Edit:

p.s.: unclear to me for font-uploads would be how to deal with font fallback. that’s an unknown complexity to me still.

Yes, once going that path it pulls quite a lot, it is def. not done in one Saturday afternoon. For your question - I’d say always fall back to default font handling, if a glyph is missing. But maybe @mintty has more insights here.