Dutis - macOS Application File Extension Manager

February 4, 2026 · View on GitHub

A comprehensive Rust application for viewing file extensions supported by macOS applications and setting default applications for file types.

Release

Features

  • 🔍 Scan System Applications: Automatically discovers all installed applications on macOS
  • 📱 File Extension Analysis: Shows which file extensions each application supports
  • 🎯 Interactive Query Mode: Search for applications that support specific file types
  • ⚙️ Default App Setting: Set default applications for file types using the duti command
  • 🚀 UTI Detection: Intelligent UTI (Uniform Type Identifier) detection with retry mechanisms
  • 📊 Categorized Display: File extensions are organized by category
  • 🔧 Auto-dependency Management: Automatically installs duti via Homebrew if not available

Installation

Prerequisites

  • macOS 10.14 or later
  • Homebrew (for automatic duti installation)
# Install dutis directly from Homebrew
brew install tsonglew/dutis/dutis

Automatic duti Installation

The application will automatically check for duti on startup and install it via Homebrew if it's not available. No manual installation is required!

Manual Installation

Build from Source

# Clone the repository
git clone https://github.com/tsonglew/dutis.git
cd dutis

# Build the project
cargo build --release

# Run the application
cargo run

Install from binary

cargo install --path .

Interactive Mode

The application starts in interactive mode where you can:

  1. View All Applications: See a comprehensive list of all applications and their supported file extensions
  2. Search by Extension: Enter a file extension (e.g., txt, pdf, py) to find supporting applications
  3. Set Default Apps: Choose an application to set as the default for a specific file type
  4. Debug Information: Access detailed scanning information

How It Works

Application Scanning

  1. System Directories: Scans /Applications, /System/Applications, and ~/Applications
  2. Info.plist Parsing: Reads each application's Info.plist file to extract supported file extensions
  3. UTI Mapping: Maps file extensions to their corresponding UTI (Uniform Type Identifier)

Default App Setting

  1. Bundle ID Detection: Uses mdls command to get the application's Bundle Identifier
  2. UTI Detection: Creates temporary files with appropriate content to detect UTI
  3. Retry Mechanism: Implements intelligent retry logic for UTI detection
  4. duti Integration: Uses the duti command to set system-wide default applications

Technical Details

Architecture

  • Modular Design: Separated into logical modules (app_scanner, plist_parser, platform)
  • Cross-Platform Ready: Platform-specific implementations with trait abstractions
  • Error Handling: Comprehensive error handling using anyhow
  • Async Ready: Designed to be easily extended with async operations

Dependencies

  • anyhow: Error handling and propagation
  • colored: Terminal output formatting and colors
  • walkdir: Directory traversal

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Community

Stargazers

Stargazers over time

Contributors

Contributors

License

This project is licensed under the MIT License.

Support

If you encounter any issues or have questions, please create an issue on GitHub.