This project has been created as part of the 42 curriculum by lfirmin, jle-neze.

Description

ft_irc is an IRC server written in C++ 98. It allows multiple clients to connect simultaneously, authenticate, join channels, and communicate in real time using the IRC protocol over TCP/IP. The server is built around a single poll() call with non-blocking I/O, handling all connections without forking.

Instructions

Compilation

make

Execution

./ircserv <port> <password>

• port : the port the server listens on (e.g. 6667)
• password : the connection password required by IRC clients

Connecting with irssi

irssi
/connect localhost <port> <password>

Connecting with netcat (for testing)

nc -C localhost <port>

Then send commands manually:

PASS <password>
NICK <nickname>
USER <username> 0 * :<realname>
JOIN #<channel>
PRIVMSG #<channel> :<message>

Available Commands

Registration

Command	Usage	Description
PASS	PASS <password>	Authenticate with the server password
NICK	NICK <nickname>	Set or change your nickname
USER	USER <username> 0 * :<realname>	Set your username and realname
QUIT	QUIT	Disconnect from the server
PING	PING <token>	Ping the server, replies with PONG

Channels

Command	Usage	Description
JOIN	JOIN #<channel> [key]	Join or create a channel
PART	PART #<channel>	Leave a channel
PRIVMSG	PRIVMSG #<channel> :<message>	Send a message to a channel
PRIVMSG	PRIVMSG <nick> :<message>	Send a private message to a user

Operator Commands

Command	Usage	Description
KICK	KICK #<channel> <nick>	Eject a user from the channel
INVITE	INVITE <nick> #<channel>	Invite a user to the channel
TOPIC	TOPIC #<channel>	View the channel topic
TOPIC	TOPIC #<channel> :<topic>	Change the channel topic
MODE	MODE #<channel> +i	Set channel invite-only
MODE	MODE #<channel> -i	Remove invite-only
MODE	MODE #<channel> +t	Restrict TOPIC to operators
MODE	MODE #<channel> -t	Remove TOPIC restriction
MODE	MODE #<channel> +k <key>	Set a channel password
MODE	MODE #<channel> -k	Remove the channel password
MODE	MODE #<channel> +o <nick>	Give operator privilege to a user
MODE	MODE #<channel> -o <nick>	Remove operator privilege from a user
MODE	MODE #<channel> +l <limit>	Set a user limit on the channel
MODE	MODE #<channel> -l	Remove the user limit

Resources

• RFC 1459 - IRC Protocol
• RFC 2812 - IRC Client Protocol
• Beej's Guide to Network Programming
• irssi documentation

AI Usage

Claude (claude.ai) was used during this project to:

• Guide the step-by-step implementation of the Server class (socket setup, poll loop, client handling)
• Explain IRC protocol concepts and numeric error codes
• Help structure the Channel class and its methods
• Debug compilation errors and logic issues

All generated content was reviewed, understood and typed manually by the authors before being integrated into the project.