extstat

⚡ Fast disk usage analyzer that groups files by extension. Perfect for finding what's taking up space on your drives.

A parallel, high-performance CLI tool that scans directories and displays disk usage statistics grouped by file extension, with beautiful terminal output.

Features

✅ Parallel scanning - Uses all CPU cores for maximum speed ✅ Beautiful table output - Color-coded results with visual bars ✅ Flexible filtering - Minimum file size, top N extensions ✅ File count tracking - See how many files per extension ✅ No dependencies - Single binary, works everywhere

Installation

From source (recommended for now)

# Clone or copy the project
cd extstat

# Build release version (optimized)
cargo build --release

# Binary will be in target/release/extstat
# Copy to your PATH
sudo cp target/release/extstat /usr/local/bin/

Usage

Basic usage

# Analyze current directory
extstat

# Analyze specific directory
extstat /path/to/directory

# Show file counts
extstat -c

# Filter small files (e.g., min 1MB)
extstat -s 1048576

# Show only top 20 extensions
extstat -n 20

# Combine options
extstat /data -c -s 1000000 -n 10

Examples

# Analyze your home directory
extstat ~

# Find what's taking space in /var
extstat /var -n 15

# Show detailed stats for current project
extstat . -c

Command Line Options

Options:
  <PATH>              Directory to analyze [default: .]
  -s, --min-size      Minimum file size to include (in bytes) [default: 0]
  -n, --top           Maximum number of extensions to display [default: 50]
  -c, --show-count    Show file count
  -h, --help          Print help
  -V, --version       Print version

Output Explanation

╭────────────┬──────────┬─────────┬──────────────────────────────────╮
│ Extension  │ Size     │ % Total │ Visual                           │
├────────────┼──────────┼─────────┼──────────────────────────────────┤
│ .fastq     │ 2.5 GiB  │ 45.23%  │ ██████████████░░░░░░░░░░░░░░░░░░ │
│ .bam       │ 1.2 GiB  │ 21.67%  │ ███████░░░░░░░░░░░░░░░░░░░░░░░░░ │
│ .fasta     │ 567 MiB  │ 10.11%  │ ███░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ │
╰────────────┴──────────┴─────────┴──────────────────────────────────╯

• Extension: File extension (or [no extension] for files without one)
• Size: Total size for all files with this extension (human-readable)
• % Total: Percentage of total scanned space
• Visual: Bar chart representation

Performance

• Parallel scanning using Rayon (uses all CPU cores)
• Typical performance: ~500k files/second on modern SSD
• Memory efficient: doesn't load file contents, only metadata

Development

Project Structure

extstat/
├── Cargo.toml       # Rust dependencies
├── src/
│   └── main.rs      # Main application code
└── README.md        # This file

Building for development

# Build debug version (faster compilation)
cargo build

# Run directly
cargo run -- /path/to/scan

# Run with options
cargo run -- . -c -n 10

Understanding the code

Key Rust concepts used:

1. Parallel iteration with Rayon:

   files.par_iter()  // Process files in parallel

2. Result handling with ?:

   let metadata = entry.metadata().ok()?;  // Return None if error

3. Pattern matching:

   path.extension()
       .and_then(|s| s.to_str())  // Chain operations safely

4. HashMap aggregation:

   let entry = acc.entry(ext).or_insert((0, 0));  // Get or create
   entry.0 += size;  // Update tuple

Adding features

Want to add more features? Common additions:

1. JSON export: Add serde and serde_json dependencies
2. Interactive TUI: Add ratatui and crossterm
3. Progress bar: Add indicatif dependency
4. Date filtering: Use file metadata modified() time

Troubleshooting

Permission denied errors:

• Use sudo for system directories
• Or skip inaccessible files (feature coming soon)

Slow on network drives:

• Network I/O is the bottleneck, not the tool
• Consider scanning locally first

Out of memory:

• Only happens with millions of different extensions
• Try filtering with -s to reduce file count

Why Rust?

• Speed: As fast as C/C++, often faster than Go/Python
• Safety: No segfaults, data races prevented at compile time
• Modern: Great tooling (cargo), helpful compiler errors
• Dependencies: Easy to manage, reproducible builds

Next Steps (Version 2)

Planned features:

• Interactive TUI mode (like ncdu)
• Drill-down: click extension → see directories
• Export to JSON/CSV
• Progress bar during scan
• Filter by date modified
• Compare two scans (before/after cleanup)

Contributing

Contributions are welcome! Please read CONTRIBUTING.md for details on our code of conduct and the process for submitting pull requests.

Changelog

See CHANGELOG.md for a list of changes in each release.

License

MIT License - Feel free to use, modify, distribute