UAPI.15 OSC 3008: Hierarchical Context Signalling

[arianvp]

Would be interesting to implement support for https://uapi-group.org/specifications/specs/osc_context/

All of systemd's tooling sends OSC-3008 signals. Which allows Terminal Emulators like ghostty to keep track of the stack of processes that have current control over the tty

[rhodes-b]

Doesn't tcgetpgrp which gets the pid of the current foreground process attached to a terminal accomplish the same thing?

from that link it sounds like it has to use the syscall I noted above except some processes wont send osc-3008 so it seems strictly worse to me
it would be harder to build a tree from this but its not impossible, you can also just parse the process tree for all the children of the terminal which sounds more robust to me as well (Its actually quite simple to implement a pstree eqivilent)

[00-kat]

This lets you disambiguate process output since it's in-band, as noted in the use cases section. I.e.: tcgetpgrp tells you who's running, this tells you who wrote what to the pty.

[jcollie]

Implementing a pstree equivalent may be "simple" but it's very platform-specific (would need individual implementations for Linux, macOS, *BSD, Windows, etc.) and when I played with it a while ago it wasn't a very fast process. And having the tree is kinda pointless because just having the tree doesn't necessarily tell you which process generated the output.

I think at least adding support for parsing OSC 3008 is useful. Once that's accomplished we can look at what implementing it more fully would mean. I think that a lot of the machinery (or at least the ideas) from handling semantic prompts can be re-used.

[00-kat]

it's very platform-specific

It also doesn't work through SSH I guess.

[jcollie]

#10900 for parsing support