chat over gemini (or, let's play with streaming text)

[indieterminacy at libre.brussels]

Omar Polo <op at omarpolo.com> writes:

> Hello,
>
> One of the things that I love about text/gemini is how it's easy to
> parse, and being it line-based it's also really easy to stream it.  When
> I started working on telescope, the idea of being able to stream content
> was present in the design of the parser from the first draft -- it also
> fit nicely with separation in multiple processes (one process does the
> fetching, another one the rendering, and messages are sent from one proc
> to the other.)  But other than knowing from the code that it should
> work, I never played with this aspect of text/gemini.
>
> Fast forward various months, I've just watched the "Why gemini" video by
> Tomasino and I got an urge to build something with streaming text.  I'm
> attaching a very, very simple CGI script that streams text/gemini to
> build an interactive chatroom.
>
> The idea is similar to the one presented by solderpunk in "A vision for
> gemini applications"
>
> gemini://gemini.circumlunar.space/users/solderpunk/gemlog/a-vision-for-gemini-applications.gmi
>
> and, frankly, I'm quite disappointed nobody has built something like
> this before.  (or at least I haven't been able to find it.  I know
> kensanata has made some experiments with a mush, but I haven't played
> with it (yet))
>
> The idea is to provide two pages: one that accepts input via the
> response code 10 and appends to a file, the second is a literal `tail
> -f'.  Simple, but it works, and it's immediate.  As soon as someone
> sends something, all the clients reading from `tail -f' gets the
> message.
>
> (the various `tail -f' gets eventually killed by a SIGPIPE when the
> client closes the connection and the server closes the script stdout.
> It could take a while due to the buffering, but can be worked out.  I
> don't know if servers are expected to kill the spawned scripts -- I
> don't recall anything from the RFC -- but I'm probably wrong.  gmid
> anyway doesn't kill the scripts, it let UNIX do its things with signals.
> Feature or bug?  dunno.)
>
> It doesn't require a client certificates, but uses the subject of it if
> provided.  There's a check that can be de-commented to enforce the usage
> of client certificates.
>
> I'm hosting a demo at
>
> 	gemini://gemini.omarpolo.com/cgi/lets-chat
>

Thanks for experimenting with this.

Ive been wondering about treating feeds as if it was a REPL, for group
projects. Ive never gotten around to IRC but Id like to think people
interoperate well in streams with heterogenous coding tricks.

> but I don't promise to keep it online.  It's a quick-n-dirty script
> (less than 50 lines of -hopefully- portable sh), probably filled with
> bugs, wrote only to be a demonstration.  I don't want to moderate it
> if/when people write things.  It's really easy to host it locally, for
> e.g. using gmid (disclaimer: I'm the author)
>
> 	$ gmid -x '*' .
>
> from the same directory where you saved the script.
>
> It seems to work with Telescope, Tinmop and Lagrange.  Kristall and
> Amfora don't seem to support streaming, or maybe I have an old version.
> Elpher doesn't stream by design.

Its always nice getting titbits comparing the browsers. Are there any
good research points which evaluate such things in a tabular way
(something I had originally planned but I lost 2 weeks with earache)?
>
> I hope this inspires someone to build amazing things with the streaming
> capability of text/gemini.  There are a lot of possibilities, for
> instance capsules like station could stream the feed, or the
> notification page; it could be better than clients continously
> refreshing the page.  Think of it like some sort of "websockets" but for
> humans ;)
>
> Gemini clients could "ring" or use some other kind of mechanism to
> inform the user that more content is available in a page (for
> e.g. Telescope adds a `!'  before the tab title.)
>

A nice touch!

> Cheers,
>
> Omar Polo
>
>
> P.S.: this is also a partial reply to the talkat spec.  I love seeing
> what creative things folks are building, and I really hope the best for
> mbays and their idea (if I got the paternity correctly :P), but I also
> like the idea of doing these sort of things over gemini.  On one hand I
> don't want to push gemini over its boundaries, on the other I love doing
> that :)
>
>
> [2. application/octet-stream; lets-chat]...


Jonathan McHugh
indieterminacy at libre.brussels