https://github.com/florianpfleiderer/mini_chat_server
A minimal chat server built with Erlang/OTP. Demonstrates lightweight processes, message passing, supervision, and OTP application structure.
https://github.com/florianpfleiderer/mini_chat_server
concurrent-programming distributed-systems erlang erlang-otp
Last synced: 8 months ago
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A minimal chat server built with Erlang/OTP. Demonstrates lightweight processes, message passing, supervision, and OTP application structure.
- Host: GitHub
- URL: https://github.com/florianpfleiderer/mini_chat_server
- Owner: florianpfleiderer
- License: apache-2.0
- Created: 2025-03-27T20:01:19.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-03-27T20:05:52.000Z (about 1 year ago)
- Last Synced: 2025-03-27T21:23:07.089Z (about 1 year ago)
- Topics: concurrent-programming, distributed-systems, erlang, erlang-otp
- Language: Erlang
- Homepage:
- Size: 7.81 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- License: LICENSE
Awesome Lists containing this project
README
# 📡 mini_chat – A Minimal Chat Server in Erlang
**mini_chat** is a simple OTP-style Erlang application that demonstrates how to build a basic chat server using:
- `gen_server` for process behavior
- `supervision` for fault-tolerance
- `application` for structured startup
Each chat user runs in their own Erlang process and can send or receive messages. The chat server also acts as a central dispatcher for general messages.
---
## 📁 Project Structure
```
mini_chat/
├── ebin/ # Compiled .beam files + .app file
│ ├── mini_chat.app
├── src/ # Erlang source files
│ ├── mini_chat_app.erl # Application entry point
│ ├── mini_chat_sup.erl # Supervisor
│ ├── mini_chat_server.erl # Chat server process
│ ├── mini_chat_user.erl # User process module
├── mini_chat.app.src # Application spec
```
---
## 🛠️ Setup & Compilation
Make sure you have Erlang installed (OTP 21 or later).
### 1. Compile all `.erl` source files
```bash
erlc -o ebin src/*.erl
```
### 2. Start the Erlang shell with code path
```bash
erl -pa ebin
```
---
## 🚀 Running the Application
In the Erlang shell:
```erlang
1> application:load(mini_chat).
2> application:start(mini_chat).
```
You should see:
```erlang
{ok,mini_chat}
```
---
## 💬 Using the Chat System
### Start users
```erlang
3> mini_chat_user:start_link(alice).
4> mini_chat_user:start_link(bob).
```
### Send a message to a user
```erlang
5> mini_chat_user:send(alice, "Hello from Bob!").
```
**Output:**
```
[alice] received: "Hello from Bob!"
```
### Send a message to the server
```erlang
6> mini_chat_server:send_msg(bob, "This is a global server message").
```
**Output:**
```
bob says: "This is a global server message"
```
---
## 🧠 What This App Demonstrates
- How to structure OTP applications
- How to use `gen_server` to encapsulate logic and state
- How to supervise components for reliability
- How to pass messages between processes
---
## 🛡️ Fault Tolerance
If any supervised process crashes, it will be automatically restarted by `mini_chat_sup`, preserving the system’s availability.
---
## 📚 Learn More
- [Erlang OTP Design Principles](https://www.erlang.org/doc/design_principles/des_princ.html)
- [The `gen_server` Behaviour](https://www.erlang.org/doc/man/gen_server.html)
- [Supervisors in OTP](https://www.erlang.org/doc/design_principles/sup_princ.html)
---
## 📦 Future Ideas
- Add a registry for active users
- Allow users to broadcast messages
- Persist chat history in ETS or Mnesia
- Turn into a distributed chat across nodes!
---