[tech] /.well-known/capability ehlo

On Sat, Dec 19, 2020 at 7:39 PM Petite Abeille <petite.abeille at gmail.com>
wrote:

Older protocols such as SMTP, POP3, IMAP, and NNTP have developed extension
> mechanism overtime:
>

However, some have not.  Multiple versions of NTP exist, but backward
compatibility is complete and there are no named extensions.
FTP, which is actually older than TCP/IP, likewise has neither extensions
nor versioning: new commands have been added and older ones have become
unnecessary, but that's all. Gopher+ was backward compatible with Gopher,
but was never widely adopted.

The principle is always the same: the client invoke a well known server
> command to list the server capabilities. The client can then use these
> extensions in coordination with the server.
>

Note however that this is not normally bilateral.  There is no way (like
Telnet WILL/WONT/DO/DONT) for the server to find out what extensions the
client supports.  Consequently, servers either have to exploit no client
extensions, or just use whatever client extensions they would like, and if
clients don't support them, tough turkey for the user.

The spirit of Gemini is that that clients and servers agree because they
all voluntarily comply with the current standard.  (Solderpunk keeps
talking about a permanent freeze, but _haud credo_.  What matters is that
evolution of the protocol document stays controlled and that software
authors have no incentive to ignore it.)

(The .sig below was chosen at random.)

John Cowan          http://vrici.lojban.org/~cowan        cowan at ccil.org
The competent programmer is fully aware of the strictly limited size of his
own
skull; therefore he approaches the programming task in full humility, and
among
other things he avoids clever tricks like the plague.  --Edsger Dijkstra
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.orbitalfox.eu/archives/gemini/attachments/20201219/6880
48ff/attachment.htm>

---

Previous in thread (8 of 20): 🗣️ Sebastian Alejandro (sebastian1231alejandro (a) gmail.com)

Next in thread (10 of 20): 🗣️ Petite Abeille (petite.abeille (a) gmail.com)

View entire thread.