💬 ft_irc

Internet Relay Chat (IRC) server implemented in C++. Supports multiple clients, channel management, and standard IRC commands over TCP/IP using non-blocking sockets and a poll-based event loop.

Build and run

Requires a C++ compiler (e.g., g++) and a POSIX environment (Linux, macOS).

git clone https://github.com/cmunoz-g/ft_irc.git
cd ft_irc
make

This produces the ircserv executable.

./ircserv <port> <password>

• <port>: TCP port to listen on.
• <password>: Connection password required from clients.

Usage

Connect using any IRC client or Netcat:

irssi --connect=127.0.0.1 --port=6667 --password=secret
# or
nc -C 127.0.0.1 6667

Supported commands

Command	Description
PASS	Authenticate with server password
NICK	Set or change nickname
USER	Register username and real name
CAP	Negotiate client capabilities (LS, REQ, END)
JOIN	Create or join channels
PRIVMSG	Send messages to users or channels
PING	Keep-alive; server responds with PONG
MODE	Adjust user or channel modes
TOPIC	View or set channel topics
KICK	Remove a user from a channel
INVITE	Invite a user to an invite-only channel
QUIT	Disconnect from the server

Features

• Multi-client support: Concurrent connections handled with non-blocking sockets and poll().
• Authentication: Clients must send PASS, NICK, and USER before joining.
• Channels: Create/join channels, set topics, keys, user limits, and invite-only mode.
• Messaging: Forward private and channel messages. Supports PING/PONG.
• Operators: Channel operators can KICK, INVITE, set TOPIC, and change MODE flags (i, t, k, l, o).
• Capabilities: Basic CAP subcommands (LS, REQ, END).
• Shutdown: Handles QUIT cleanly and frees client resources.

Implementation details

The server follows an event-driven model:

1. Server socket: A single listening socket is created, set non-blocking, and registered with poll().
2. Event loop: poll() monitors listening and client sockets for input.
3. Connections: New sockets accepted, set non-blocking, and tracked.
4. Message parsing: Input is buffered until complete commands (\r\n) are received, then parsed by Message.
5. Command dispatch: Commands routed to handler methods in Server.
6. Clients: Each Client tracks its socket, state, buffer, modes, and channels.
7. Channels: Channel manages members, operators, modes, topics, and invitations.

Code structure

• main.cpp: Entry point, signal setup, argument parsing, server start.
• Server.hpp / Server.cpp: Core event loop, connection handling, command routing.
• ServerConnection.cpp: Socket setup, accept(), non-blocking configuration, client removal.
• ServerCommands.cpp: IRC command handlers.
• ServerUtils.cpp: Utilities for broadcasting, nickname checks, registration.
• signal.cpp: Signal handling for clean shutdown.
• utils.cpp: Logging, error handling, string conversion, mode validation.
• Client.cpp: Client state, buffers, modes, and channel tracking.
• Channel.cpp: Channel state: members, operators, modes, topics, invites.
• Message.cpp: Command parsing and mapping to enums.