csum

Introduction

csum is a CLI program which allows you to to verify checksums. The goal of csum is to minimise the effort required when you download a file and want to verify the checksum.

The advantages of csum over the native checksum utilites are as follows:

• You don't have to compare checkums by eye, which might be required on some platforms.
• It's easier to type.
• It's the same on all platforms.
• You don't have to type which checksum algorithm is being used.

csum supports the most common checksum algorithms:

• MD5
• SHA256
• SHA512
• SHA1

In addition, it supports SHA3_512, SHA224, BLAKE2S, SHA3_224, SHA3_256, SHA3_384, SHA384 and BLAKE2B.

Requirements

You need to have Python 3.6 or higher installed. This will allow you to install csum with Python's package manager, pip.

How to install

To install csum with pip, run the command:

pip install csum

After this command completes, the csum executable should be available on the PATH.

Quick start

csum is designed to be as simple to use as possible. For this reason, you don't need to specify the checksum type (e.g. sha256); csum will iterate through the most common types first.

When you use csum, the response will be something like:

        --------------------------------------------------------------------------------

        File: file.zip
        Algorithm: SHA256

        Expected checksum:    40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2
        Calculated checksum:  40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2

        Checksums match ✔

        --------------------------------------------------------------------------------

SUCCESS: SHA256 checksum matched file.

Usage examples

File and checksum

You can call csum with a filename and expected checksum:

csum file.zip 40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2

Or an expected checksum and filename:

csum 40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2  file.zip 

Absolute or relative paths, and paths including tilde (~), are accepted:

csum ~/Downloads/file.zip 40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2  

Preformatted checksum/filename

Sometimes you are provided with an expected checksum of the form:

40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2 file.zip

Assuming that the file is in the current working directory, you can simply copy this text and paste it after the csum command:

csum 40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2  file.zip

If you prefer, you can supply it as a single argument:

csum "40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2  file.zip"

Tip: The number of spaces between the checksum and filename doesn't matter in either case.

Manually choosing an algorithm

If you prefer to select a particular algorithm instead of iterating through them, you can use the -a/--algorithm parameter.

For example, using the SHA256 algorithm only:

csum -a sha256 file.zip 40f66f20b1ecb05cb11a9627520aafafbc8cd86b33eb8019cbea9925d8ca83ce2

Tip: You can provide the algorithm name as either lower-case or upper-case, e.g. sha256 or SHA256.

License

You may freely use, modify and redistribute this program under the terms of the MIT License. See LICENSE.