This is the story of me prototyping a minimal IRC server in Python.
Discord
Discord is the Electron of chat:
- It has the features people want
- It just works
- (Almost) Everyone uses it
- ...and it's completely unusable on the old, slow computers I toy with
There are several open source alternatives to Discord, including Revolt and Gitter. Their flagship clients look heavyweight, but the beauty of open source is that there's almost always an alternative terminal client. I'll investigate those in time. There's also a decentralized option, Matrix, which apparently has more than 100 million users. Uh, wow. I should probably try Matrix!
But I didn't realize Matrix had so many users at the time, so I decided to instead try a chat protocol that was designed for old computers.
Internet Relay Chat
Wikipedia says IRC was created in 1988. I haven't used IRC much and, when I have, I found it to be unapproachable.
Problems with IRC
- There are commands you have to remember (and any typo might send your flawed command line straight into the chat window for all to see)
- All IRC servers I've used broadcast your hostname when you connect, unless you setup an account (this guy uses Comcast!!!)
- With IRC, you generally only receive messages while online, so you have to stay connected (or use a "bouncer") if you want to actually see responses
- There isn't a convenient, free iOS app for IRC, so IRC basically doesn't exist for many people
I feel like most of these limitations could be easily overcome.
Solving IRC's problems
Obvious solutions:
- Have actual UI for commands, instead of relying on perfectly-entered text commands
- Hide hostnames by default (at least from non-operators)
- Store past messages in a sequential database and allow clients to request old messages -- note: this seems ripe for AI scraper abuse, and it would require opt-in protocol changes
- Build a simple web client, optionally create native phone apps, and, of course, supply a lightweight TUI!
Once you throw in account management and privacy controls, this could get out of hand quickly. And Matrix already exists and has probably solved these problems.
Not solving IRC's problems
My original motivation for investigating chat apps was to see what it would take to setup my own little chat room. I'm still not convinced I need a chat room, and I'm almost certain it wouldn't get much use, so let's cut some corners:
- Bridging multiple servers? Who cares!
- Encryption and user accounts? Not needed, since it's just for fun!
- Tracking and querying old messages? Maybe just cache the last 10!
- Instead of building any apps, just reuse existing IRC clients!
- Operators? Probably a good idea, but not implemented
I don't know if worse is better, but it's certainly easier!
And thus, pirc was born.
pirc
pirc is basically a learning experiment to see how simple an IRC server can be. The entire server is in a single ~350 line Python file, with no dependencies beyond the Python standard library. The code uses a minimum of abstraction (most of the server is one big match statement). It is almost certainly not spec-compliant (since I couldn't actually determine which IRC spec to work off of--IRC has evolved organically, for better or worse), but it seems to work with HexChat, Irssi, and WeeChat.
The code is rough, but should be readable, so I won't attempt to explain it here. Here are some things I learned along the way:
- Python's
socketservermodule doesn't seem to have a simple way to detect when clients disconnect (so I switched to theselectorsmodule instead) - In Python,
textwrap.wrap("")returns[]instead of[""] - I still think IRC should not broadcast hostnames by default (at least to non-operators)
- IRC clients send all commands in CAPITAL letters (e.g.
JOIN), except the "message of the day" command (motd), which is sent in lowercase (why!?) - To my surprise, private messages and messages sent to channels are both
PRIVMSGcommands (just directed to a channel instead of a nickname)
Test server
Update: the test server has been taken offline.