TNT

TNT's Not Tunnel - A lightweight terminal chat server written in C

Features

• ✨ Vim-style operations - INSERT/NORMAL/COMMAND modes
• 📜 Message history - Browse with j/k keys
• 🕐 Full timestamps - Year-month-day hour:minute with timezone
• 📖 Bilingual help - Press ? for Chinese/English help
• 🌏 UTF-8 support - Full support for Chinese, Japanese, Korean
• 📦 Single binary - Lightweight ~50KB executable
• 🚀 Telnet access - No client installation needed
• 💾 Message persistence - All messages saved to log file
• ⚡ Low resource usage - Minimal memory and CPU

Building

make

For debug build:

make debug

Running

./tnt

Connect from another terminal:

telnet localhost 2222

Usage

Operating Modes

• INSERT - Type and send messages (default)
• NORMAL - Browse message history
• COMMAND - Execute commands

Keyboard Shortcuts

INSERT Mode

• ESC - Enter NORMAL mode
• Enter - Send message
• Backspace - Delete character
• Ctrl+C - Exit

NORMAL Mode

• i - Return to INSERT mode
• : - Enter COMMAND mode
• j - Scroll down (older messages)
• k - Scroll up (newer messages)
• g - Jump to top
• G - Jump to bottom
• ? - Show help
• Ctrl+C - Exit

COMMAND Mode

• Enter - Execute command
• ESC - Cancel, return to NORMAL
• Backspace - Delete character

Available Commands

• list, users, who - Show online users
• help, commands - Show available commands
• clear, cls - Clear command output

Architecture

• Network: Multi-threaded TCP server
• TUI: ANSI escape sequences
• Storage: Append-only log file
• Concurrency: pthread + rwlock

Configuration

Set port via environment variable:

PORT=3333 ./tnt

Technical Details

• Written in C11
• POSIX-compliant
• Thread-safe operations
• Proper UTF-8 handling for CJK characters
• Box-drawing characters for UI

License

MIT License - see LICENSE file