duf Modern Disk Usage and Free Utility
duf is a modern disk usage/free utility written in Go that provides a polished, colorful terminal output for mounted filesystems. It replaces the traditional df command with better formatting, JSON output support, and smart filtering by filesystem type.
duf is a modern disk usage/free utility written in Go that provides a polished, colorful terminal output for mounted filesystems. It replaces the traditional df command with better formatting, JSON output support, and smart filtering by filesystem type.
npx skills add agentskillexchange/skills --skill duf-modern-disk-usage-free-utility
Overview
duf (Disk Usage/Free) is a modern replacement for the classic df command, written in Go. While df outputs raw, hard-to-read columns, duf presents filesystem information in a clean, colorful table with progress bars, grouped by device type (local, network, special/virtual), and with human-readable sizes by default.
Key Features
- Beautiful Terminal Output: duf formats disk usage information in colorful tables with Unicode progress bars showing percentage used, making it immediately readable at a glance.
- Smart Grouping: Filesystems are automatically grouped into categories — local devices, network volumes, and FUSE/special mounts — reducing clutter from pseudo-filesystems.
- JSON Output: Full JSON output mode (
duf --json) for programmatic consumption, making it easy for agents and scripts to parse filesystem data. - Filtering: Filter displayed filesystems by type, mount point, or device path. Show only specific filesystem types or hide types you do not care about.
- Sorting: Sort output by any column — size, used space, available space, usage percentage, filesystem type, or mount point.
- Cross-Platform: Works on Linux, macOS, Windows, FreeBSD, and other platforms with consistent output formatting.
How It Works
A skill wrapping duf enables AI agents to quickly assess disk space across all mounted volumes on a system. The agent invokes duf --json to get structured data about every filesystem, including total size, used space, available space, and mount points. This is essential for diagnostic runbooks, deployment checks, and system monitoring tasks where the agent needs to verify sufficient disk space before proceeding.
Technical Details
duf is written in Go and distributed as a single binary. It can be installed via Homebrew (brew install duf), package managers, or downloaded from GitHub releases. The tool reads filesystem information from the operating system’s mount tables. It is released under an open-source license with nearly 15,000 GitHub stars. The binary is small, fast, and has zero runtime dependencies.
Integration Points
- JSON output for structured data parsing by agents and scripts
- Configurable columns and sort order via command-line flags
- Theme support for different terminal color schemes
- CI/CD integration for pre-deployment disk space checks