🔍 Port Checker CLI

A powerful, developer-friendly CLI tool to inspect local TCP ports, detect protocols, and manage processes — all with elegant output and zero setup.

🚀 Features

• ✅ Detect if a TCP port is open
• 🌐 Auto-detect HTTP, HTTPS, MySQL, AMQP & more
• 🧩 Show the bound process (with optional kill prompt)
• 🧠 Protocol guessing using banner grabbing
• ✨ Developer-friendly, color-coded output
• 🧪 Lightweight and zero-dependency install (except chalk)

📦 Installation

npm install -g port-checker-cli

Or run directly with npx (no install):

npx port-checker-cli 8080

⚡ Usage

port-checker <port>

Example:

port-checker 3306

$ port-checker 8243

┌─────────────────────────────────────┐
│ ✅  Port 8243 is OPEN               │
└─────────────────────────────────────┘

🌐  HTTP(S) Response:
    Protocol: HTTPS (handshake failed)

🧩  Bound Process:
    java (pid: 35916)
    Command: Listening on (LISTEN)

⚠️  Do you want to kill process 35916? (y/n): y
✅ Process 35916 terminated.

📋  Summary:
    Port: 8243
    Protocol: HTTPS (handshake failed)
    PID: 35916
    Status: Open

🛠 Developer Notes

• If you're checking ports owned by root/system services (like mysqld), use sudo:

  sudo port-checker 3306

• Supports graceful exit, no hangs, and handles TCP timeout conditions smoothly.

• Protocol detection includes:

  • HTTP / HTTPS
  • MySQL
  • AMQP (JMS)
  • Custom banners (extensible)

🔐 Permissions & Security

This tool uses:

• lsof or sudo lsof to inspect port bindings
• net.Socket() for low-level TCP probing
• No external APIs or telemetry

You're in full control. No internet required.

👨‍💻 Author

Charith Jayasanka
Senior Software Engineer | Dev Tool Enthusiast
GitHub • LinkedIn

📝 License

MIT © 2025 Charith Jayasanka