[dakra]

Hi! Maintainer of Ghostel here.

baokaola and I actually wanted to do a "Show HN" next week, but looks like someone was faster submitting the link.

Have a look at the GitHub repo which is a bit nicer for a quick overview: https://github.com/dakra/ghostel

To add some context, Ghostel is a terminal emulator for Emacs powered by libghostty-vt.

There's a feature comparison vs vterm and eat: https://dakra.github.io/ghostel/#ghostel-vs-vterm

And here is a gist with images to compare performance and correctness: https://gist.github.com/dakra/4a0b76ebcf5d52338e134864378465...

But for me personally, it has not only replaced vterm/eat but also any other external terminal like kitty/Ghostty.

Having your terminal text just like a normal Emacs buffer opens up so many possibilities and extension points that are just not available on any other terminal.

Even simple stuff like searching in the scrollback, then navigating and selecting+copying a paragraph only with the keyboard. For every Emacs user that's so natural and fast in Ghostel while often cumbersome in other Terminals where I just reach to the mouse because it's easier.

Happy to answer any questions and also like to hear feedback positive or negative.

If you're an Emacs user and tried Ghostel and are still using Ghostty (or another external Terminal), is there something Ghostel is missing or is it just because you want some processes to run outside of Emacs?

baokaola and I are also very active on GitHub, so feel free to open an issue if you have any.

[aardvark179]

I think the thing that stops me from running more processes inside emacs is that a large diff parse from magit or similar can block everything, and so I end up keeping a separate terminal around anyway.

[mort96]

Huh is that true? Does running a command in a terminal buffer block all of EMacs? That's extremely surprising, the main use of these kinds of integrated terminals for me is to compile and run which means long running commands. Is this use case fundamentally not supported due to EMacs's architecture?

[aardvark179]

No, running a command in a terminal buffer doesn’t block the emacs UI, but a long running bit of elisp running in emacs can block the UI.

[sintax]

Surprised we haven't seen an LLM-rewrite to <insert favourite language> rewrite of emacs yet!

[4xel]

Like https://lem-project.github.io/ ? (not vibe coded btw, even better!)

[sintax]

Interesting.. although if I ever switch, it'd be to an emacs spawn that didn't use lisp as language.

[b3n]

Hi dakra!

> is there something Ghostel is missing

eshell allows me to manipulate text as I would in any other Emacs buffer. If I have a function which wraps a word in quotes, and bind it to a key, I can be confident it will work in eshell like it does anywhere else. It's a real killer feature. If I use evil-mode, or xah-fly-keys, or simply want to use ispell to correct the spelling of a word, it all works.

Unfortunately with Ghostel none of this works. It's not integrated in the same way. There are extensions like evil-ghostel-mode, but they are limited.

Are there any plans to improve this, or is it a limitation Ghostel has to live with?

A Ghostel equivalent of eat-eshell-mode would be amazing.

[dakra]

Did you see ghostel line-mode? This basically gives you a `M-x shell` experience where everything is a buffer and nothing is send to the terminal until you press enter.

There you could type on the prompt line and then call jinx or your quote wrapping function etc as it's just a normal Emacs buffer. You can't edit the scrollback buffer though, but I don't think that's possible in eshell either.

But line-mode has it's own set of problems. Since we don't send anything to the shell, you could have some problems with autocomplete or similar things that change the text depending on each typed char. Similarly we automatically disable line-mode when you enter a TUI (alt-screen) app, as line-mode doesn't make too much sense in e.g. vim. But that's configurable and you can still force line-mode, it really depends on the TUI apps.

We try to support as much as possible and work around things like fish autocomplete etc. But please try and report any issues you find.

[accelbred]

Editing scrollback is possible in eshell, and something I use often.

[dakra]

Ah. I tested it before but now I see that I have `(setq eshell-scroll-to-bottom-on-input 'all)` in my config which always snapped point back to the prompt when I tried to edit the scrollback.

Anyway, unfortunately that is not possible in a Ghostel buffer and most likely also will never be. I'm open to ideas though how we could improve or replicate your eshell workflow.

But also, eshell is awesome and Ghostel is not a replacement for it. It's more a replacement for term.el, maybe shell.el (with line-mode) and other terminal packages like eat and vterm.

[MarsIronPI]

I think issue #426[0] would be sufficient, since it would allow for editing after the command is finished. I understand that it probably won't happen any time soon, but embedding a full terminal emulator in Eshell is the thing that's got me staying on EAT right now.

Ghostel looks really nice though!

[0]: https://github.com/dakra/ghostel/issues/426

[dakra]

Noted.

I didn't even think of the use-case that then you can edit output from finished commands in the scrollback. But it makes sense and is another +1 for that feature request.

[arikrahman]

Howdy,

Awesome project. Been using with doom for a while. How do you manage to get scrolling programs to work (eg Lazygit or Reasonix) where other emulators fail? Is it something special in your implentation or library that makes this work?

[baokaola]

Are you thinking about using the scroll wheel of the mouse to scroll within the program? If the appropriate terminal modes are enabled by the application running in the terminal, we capture the scroll events in Emacs and forward them to the terminal instead of letting Emacs handle them.

[arikrahman]

Yes, that's what I mean. That's interesting because I could never get it to work properly on vterm. I suspected maybe a better base with ghosttylib might be fixing things.

[xoxolian]

Yeah, Ghostel works great for me so far!

Two things: - defined f1 to toggle between semi-char vs copy modes - I ask myself "Is it ok if Emacs dies or I nuke it?" If not, then I execute a command in the normal terminal

[dakra]

> defined f1 to toggle between semi-char vs copy modes

this is useful anyway but just in case you didn't know, we automatically switch to copy-mode when it makes sense.

E.g. when you activate mark, click somewhere with the mouse or when point leaves the current prompt position.

That means that with isearch or consult-line etc you're automatically in copy-mode (because why else would you search something and then jump to that position).

For other commands like avy or flash jump packages I have this in the documentation:

;; A package that runs a hook after jumping (e.g. flash): (add-hook 'flash-after-jump-hook #'ghostel-maybe-leave-input)

;; A package without one (e.g. avy) — advise its jump action: (with-eval-after-load 'avy (advice-add 'avy-action-goto :after #'ghostel-maybe-leave-input))

Personally I use copy mode a lot but I rarely have to "manually" activate the mode.

[jaaron]

Commenting late, but just want to thank you for this. I've been using it for a bit now, replacing vterm for my setup. I'll be sure to submit feedback via github.

[helibom]

Wish it had the pattern based Quick-select mode from WezTerm. Since I discovered that I never want to use another term.

[dakra]

You have the full power of Emacs to your disposal.

I have never used WezTerm but from a quick look, it seems you can quickly copy text ace-jump style.

In Emacs you could use e.g. avy to do the same, but there is probably a bunch of other similar packages that do the same.

And additionally you're not restricted to just select/copy a word. You can freely move around and use e.g. expand-region or similar to quickly select more.

It's Emacs after all, the possibilities are endless ;)

[sigbottle]

How was integration for you guys? Was the integration easier for you guys since you have an established emacs system consuming terminal output with reasoned semantics over what goes where for existing subsystems (rendering, osc codes, etc)?

For libghostty-vt, since you're targeting a terminal TUI instead of an external subsystem (for example; for ghostty, you hit libghostty-vt -> GPU rendering, which is external), you still have to buy into terminal semantics. in my experience, since I was trying to replicate mosh with libghostty-vt as the parser, what happened was that my optimized re-rendering kept getting increasingly coupled to terminal semantics (and the UDP state update model too), otherwise I'd have to send the entire terminal grid over the network like, every time.

What are the tricks for making this both performant and not like, utter cancer? You have a harder issue here too (similar to tmux) in that certain optimizations are just not available to you, or you have to translate (literally geometrically) certain instructions

[baokaola]

I'm not entirely sure what you're asking. But I'll answer to the best of my abilities:

For Ghostel, libghostty-vt is the source of truth and the architecture is essentially that we serve input to the PTY and the PTY serves output to libghostty-vt which builds out the state in the form of a terminal screen structure. The goal is then to keep the contents of an Emacs buffer up to date to this terminal screen without replace the entire thing every time we redraw. We make use of mainly two things in order to do as little work as possible: - Scrollback is immutable and thus never has to be modified unless it's evicted, alt screen is activated, dimensions change etc. - libghostty-vt maintains row level dirty flags that we scan to make sure we're only replacing lines that have actually changed.

So for the rendering part, we're only diffing the grid state against the buffer, not doing anything based on terminal semantics per se, parser events that draw to the screen are passed straight to the terminal handler. But of course, certain things we need to hook into such as directory and title changes, of clipboard events etc.

Might also add that we're using the direct Zig API, not the C API, which means we have access to things that aren't exposed in the C API.