It's quite crude, since all I needed was the current branch name and the hash. git internally does a bunch of cache warming and verification that make it slower, so I just don't do that. The code is in my dotfiles[1].
I've been meaning to update it to include more information but I really don't want to have to touch packfiles in shell.
Thanks! Parsing git information without using git has always been mildly interesting to me :)
This is most definitely for zsh, FWIW; I choked slightly on `echo $var[1,12]` for a minute there. That's not a problem - you wrote this for your shell prompt, you use zsh, it makes sense to use zsh features - I'm just noting that others might need to do a bit of porting.
(I personally use bash by choice myself because it's the most widely installed shell and I don't want to switch until I fully know how to make the most concise and least surprising use of it.)
I've been meaning to update it to include more information but I really don't want to have to touch packfiles in shell.
[1]: https://github.com/cyphar/dotfiles/blob/acbd9096a1daead80ba5...