bcfv

bcfv is a Bash frontend to checksum programs (SHA, Blake3, MD5) to calculate, update and verify checksums through directory tree. Inspired by Python based cfv.

Operations

bcfv is very simple. It creates checksum (.checksum.xxx) files for each directory with files. The checksum file format is always the native file format of the underlying checksum program. The suffix of the checksum file varies by checksum algorithm (.b3 for Blake3, .sha256 for SHA-256, etc.).

Install

1. Copy bcfv to PATH and give it exec permissions

# example
cp bcfv /usr/local/bin
chmod a+rx /usr/local/bin/bcfv

2. Install required checksum programs:

• Blake3 (default): b3sum
• MD5: md5sum
• SHA-256: sha256sum
• SHA-512: sha512sum

Most UNIX-like OS have md5sum, sha256sum and sha512sum installed by default.

Usage

Usage: bcfv [-hqdcu] [-b DIR] DIR [DIR1 ...]
        -h      Display help
        -q      Do not print checksums
        -c      Check existing checksums
        -u      Update changed checksums
        -d      Add date to previous checksum version
        -a ALGO Select checksum algorithm: b3, md5, sha256, sha512. Default is b3
        -b DIR  Base directory for the operations
By default, the program will *create* checksums

Motivation

I wrote bcfv since my old trusted Python 2.7 based cfv stopped working as distros like Debian/Ubuntu moved to Python 3. cfv had been long dormant and unmaintained, so I decided to write the same functionality using Bash shell only hoping I would not need to touch the code again for the next 20 years :-)

However, it seems the cfv project has been resurrected and a Python 3.x based version is about to come out. I have not made any performance benchmarking yet, but I believe cfv will outperform bcfv.

Performance never was a priority for bcfv, but a reliable operation and an implementation that would require minimal maintenance and had minimal dependencies. I also wanted to be able to verify the checksums directly with the underlying checksum tools (b3sum, sha256sum, etc.)