Gustasum: Partial Checksumming Done Right! 🚀

Ever wanted a checksum tool that’s smart, blazing fast, and designed with real-world usability in mind? Look no further! Gustasum combines the speed of partial checksumming with a suite of features that make file integrity verification a breeze. Gustasum is your go-to utility for partial checksumming, a perfect balance between speed and reliability.

In an age of terabyte drives and colossal files, traditional full checksums can be overkill. Enter partial checksumming, the art of verifying just enough of a file to confidently ensure its integrity.

With Gustasum, you can:

• Verify large datasets quickly without reading entire files.
• Track file changes, validate backups, and confirm copy operations—all with speed and efficiency.
• Customize behavior to suit your workflows, from tweaking chunk sizes to remapping base paths during validation.

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Key Features 🔑

• Smart Checksumming: Reads the first, middle, and last 100 bytes of a file for rapid verification.
• Flexible Validation: Validate files using a checksum file and optional base path remapping.
• Progress Feedback: Track your operations with stylish progress bars (automatically hidden in scripts).
• Error Handling: Skip files with errors or halt the process, your choice!
• Customizable: Adjust chunk size, include modification time in hashes, or keep things lean with defaults.
• Modern: Built in Rust for performance and reliability.

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Real-World Applications 🌎

1. File Copy Validation

Copied a huge folder? Use Gustasum to confirm everything copied intact:

gustasum /source/directory > source_checksums.txt
gustasum --check source_checksums.txt --remap /source /destination

2. Backup Integrity

Backups are critical, but are they reliable? Use Gustasum to ensure data hasn’t changed over time:

gustasum /backup/directory > backup_checksums.txt
gustasum --check backup_checksums.txt

3. Deduplication

Find duplicate files efficiently by comparing partial checksums.

4. Quick Verifications

Need a sanity check but don’t want to wait hours for a full checksum? Gustasum’s partial checksumming delivers confidence in seconds.

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Installation

From Source

1. Clone the repository:

   git clone https://github.com/ghagl/gustasum.git
   cd gustasum

2. Build the project:

   cargo build --release

3. Run Gustasum:

   ./target/release/gustasum

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Usage Examples

1. Generate Partial Checksums

Generate checksums for all files in a directory:

gustasum /path/to/directory > partial_checksums.txt

2. Validate Checksums

Validate a directory against previously generated checksums:

gustasum --check partial_checksums.txt

3. Handle Path Changes

Validate files where the directory structure has changed:

gustasum --check partial_checksums.txt --remap /old/base/path /new/base/path

4. Include Modification Time

If you’ve used tools like cp -p to preserve file modification times, include modtime in your hashes:

gustasum --include-modtime /path/to/directory > partial_checksums_with_modtime.txt
gustasum --check partial_checksums_with_modtime.txt --include-modtime

5. Customize Chunk Sizes

Increase or decrease the bytes read from the file’s start, middle, and end:

gustasum --partial-bytes 256 /path/to/directory > custom_checksums.txt

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Command Overview

Basic Commands

• Generate Checksums: gustasum /path/to/files > checksums.txt
• Validate Checksums: gustasum --check checksums.txt

Options

• --partial-bytes <N>: Number of bytes to read from start, middle, and end of files (default: 100).
• --include-modtime: Include modification time in hashes.
• --remap <OLD_BASE> <NEW_BASE>: Adjust file paths during validation.
• --skip-errors: Skip files that produce errors during reading or metadata access.
• --check <FILE>: Validate files against a checksum file.

Examples

For more examples, run:

gustasum --help

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License

This project is licensed under the GNU General Public License v3.0 (GPLv3). See LICENSE for details.

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Contributing

Gustasum is a personal project, but contributions are always welcome! If you encounter bugs, have feature requests, or want to make Gustasum even better, feel free to:

1. Open an issue.
2. Submit a pull request.
3. Share your feedback.

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Why Gustasum?

Because life’s too short to wait for full checksums. Gustasum is fast, reliable, and designed for you, the pragmatic power user. Whether you’re managing backups, verifying file copies, or tackling large datasets, Gustasum makes it fun to care about file integrity.

So go ahead—try Gustasum today, and bring speed and confidence to your file operations! 🚀