taildir

A lightweight Node.js directory watcher that monitors file changes recursively and outputs new content as it's appended - similar to tail -f but for entire directories.

Features

• Recursively watches all files in a directory tree
• Outputs only new content when files grow (like tail -f)
• Filter by file extensions (e.g., watch only .log files)
• Ignores hidden files and temporary files
• Lightweight - uses only native Node.js libraries
• Trims empty lines from output

Installation

npm install -g taildir

Or run directly with npx:

npx taildir <directory>

Usage

Watch the current directory:

taildir

Watch a specific directory:

taildir /path/to/directory

Watch only specific file extensions:

taildir /path/to/directory -e js,ts,json
taildir --ext log,txt

Example Output

Starting to watch: /home/user/logs
Press Ctrl+C to stop

==> /home/user/logs/app.log <==
[2024-01-15 10:30:45] Application started
[2024-01-15 10:30:46] Connected to database

==> /home/user/logs/error.log <==
[2024-01-15 10:31:02] ERROR: Failed to process request

How It Works

• When starting, taildir records the current size of all files
• When a file grows, it reads and displays only the new content
• New files created while watching will show their complete content
• Files that shrink (truncated) are tracked but don't produce output
• Hidden files (starting with .) are ignored

Use Cases

• Monitor application logs across multiple files
• Watch output directories for generated content
• Track changes in data files
• Debug file-writing applications

Requirements

• Node.js >= 14.0.0

License

MIT