IRC_42

A small multi-client IRC server built in C++98 with sockets and poll().

IRC • sockets • poll() • channels • C++98

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📌 Overview

IRC_42 is a project developed as part of the 42 curriculum.

The repository currently contains ft_irc, an IRC server that accepts multiple TCP clients, authenticates them with PASS, NICK, and USER, and implements a practical subset of IRC commands for messaging, channels, and operator actions.

This project focuses on:

• socket programming and TCP server lifecycle
• event-driven I/O with poll()
• IRC command parsing and reply handling
• channel and client state management

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✨ Features

• ✅ multi-client TCP server loop based on poll()
• ✅ registration flow with PASS, NICK, and USER
• ✅ channel creation, join/leave flow, and channel listing with JOIN, PART, and LIST
• ✅ private and channel messaging with PRIVMSG
• ✅ operator-oriented commands and modes with KICK, INVITE, TOPIC, MODE, and PING
• ⚠️ automated command coverage is still incomplete: ft_irc/tests/test_commands.sh is currently empty

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🧠 Concepts Covered

Through this project, I worked on the following concepts:

• TCP sockets with socket(), bind(), listen(), accept(), send(), and recv()
• multiplexed I/O with poll()
• C++98 class design and separation of responsibilities
• command parsing with std::istringstream
• incremental network-buffer handling for IRC messages
• manual resource cleanup for sockets, clients, and channels

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🛠️ Build

Clone the repository and compile the project:

git clone git@github.com:Middle-555/IRC_42.git
cd IRC_42/ft_irc
make

Available Makefile rules:

make
make clean
make fclean
make re

Additional build notes:

• the Makefile is located in ft_irc/
• the current executable name is ircserv
• the current compile flags are -Wall -Wextra -Werror -std=c++98 -g

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🚀 Usage

Run the program with:

./ircserv <port> <password>

Examples

./ircserv 6667 mypassword
nc 127.0.0.1 6667
echo -e "PASS mypassword\nNICK user1\nUSER u1 0 * :User One\nJOIN #test\n" | nc 127.0.0.1 6667

Usage notes:

• main.cpp currently validates ports only in the [1024, 65535] range
• the repository also includes manual test scenarios in documentation/testcommand.txt
• some older helper scripts still refer to ./irc; the current Makefile builds ./ircserv

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📂 Project Structure

.
├── ft_irc/
│   ├── Makefile
│   ├── include/
│   │   ├── Channel.hpp
│   │   ├── Client.hpp
│   │   ├── CommandHandler.hpp
│   │   └── Server.hpp
│   ├── src/
│   │   ├── Channel.cpp
│   │   ├── Client.cpp
│   │   ├── CommandHandler.cpp
│   │   ├── Server.cpp
│   │   └── main.cpp
│   └── tests/
│       ├── killIRC.sh
│       ├── test_commands.sh
│       └── test_connection.sh
├── documentation/
│   ├── IRC ref Protocole.pdf
│   ├── Roadmap.txt
│   ├── fr.subject.pdf
│   └── testcommand.txt
├── template.md
└── README.md

Structure Details

• ft_irc/include/ : class declarations for the server, clients, channels, and command dispatcher
• ft_irc/src/ : program entry point, server loop, command handling, and channel/client behavior
• ft_irc/tests/ : helper scripts for build, connection smoke tests, and process cleanup
• documentation/ : roadmap, subject files, protocol references, and manual command examples

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⚙️ Project Constraints

This project follows the constraints visible in the repository and in the 42 ft_irc context:

• written in C++98
• compiled with -Wall -Wextra -Werror
• centered on low-level socket APIs and poll()
• includes explicit cleanup of allocated clients and channels
• implements a subset of IRC behavior around authentication, channels, messaging, and operator actions

The repository also contains the official subject PDF in documentation/fr.subject.pdf.

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🧪 Testing

The repository currently provides or documents the following testing approaches:

• build and smoke testing with ft_irc/tests/test_connection.sh
• manual connection and registration checks with nc
• multi-client channel scenarios documented in documentation/testcommand.txt
• operator and channel-mode scenarios with KICK, INVITE, TOPIC, and MODE
• memory checking guidance with valgrind

Manual test examples

cd ft_irc && ./ircserv 6667 mypassword
nc 127.0.0.1 6667
PASS mypassword
NICK user1
USER u1 0 * :User One
JOIN #test

Memory checks

valgrind --leak-check=full --show-leak-kinds=all ./ircserv 6667 mypassword

Testing notes:

• ft_irc/tests/test_commands.sh is empty for now
• ft_irc/tests/test_connection.sh still checks for ./irc, so it should be updated if you want the script to match the current Makefile output

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📖 What I Learned

This project helped me improve in the following areas:

• designing an event-driven server around poll()
• structuring IRC command parsing into dedicated classes and handlers
• managing shared state between clients, channels, and operator permissions
• handling cleanup paths for disconnects, shutdown, and allocated resources

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🚧 Possible Improvements

Although the project already has a working base, several improvements could be considered:

• complete the automated test suite in ft_irc/tests/
• align helper scripts and documentation around the current executable name ircserv
• improve RFC-level reply consistency and error coverage
• model multiple joined channels per client instead of a single currentChannel

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👤 Authors

• Kevin Pourcel (Middle) - 42 student - GitHub
• Adrien Cabarbaye - 42 student