https://github.com/brianloveswords/buffer-crc32

A pure javascript CRC32 algorithm that plays nice with binary data
https://github.com/brianloveswords/buffer-crc32

Last synced: 3 months ago
JSON representation

A pure javascript CRC32 algorithm that plays nice with binary data

• Host: GitHub
• URL: https://github.com/brianloveswords/buffer-crc32
• Owner: brianloveswords
• License: mit
• Created: 2012-07-11T17:50:29.000Z (over 12 years ago)
• Default Branch: master
• Last Pushed: 2024-02-06T17:57:12.000Z (12 months ago)
• Last Synced: 2024-11-05T20:12:29.533Z (3 months ago)
• Language: JavaScript
• Homepage:
• Size: 39.1 KB
• Stars: 97
• Watchers: 5
• Forks: 30
• Open Issues: 7
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-nodejs-pure-js - buffer-crc32

README

        
# buffer-crc32

[![NPM Version](https://img.shields.io/npm/v/buffer-crc32.svg)](https://npmjs.org/package/buffer-crc32)

[![Build Status](https://github.com/brianloveswords/buffer-crc32/actions/workflows/ci.yml/badge.svg)](https://github.com/brianloveswords/buffer-crc32/actions/workflows/ci.yml)

crc32 that works with binary data and fancy character sets, outputs

buffer, signed or unsigned data and has tests.

Derived from the sample CRC implementation in the PNG specification: http://www.w3.org/TR/PNG/#D-CRCAppendix

This package requires Node 8+ to work.

# install

```

npm install buffer-crc32

```

# example

```js

const crc32 = require('buffer-crc32');

// works with buffers

const buf = Buffer([0x00, 0x73, 0x75, 0x70, 0x20, 0x62, 0x72, 0x6f, 0x00]);

crc32(buf); // -> 

// has convenience methods for getting signed or unsigned ints

crc32.signed(buf); // -> -1805997238

crc32.unsigned(buf); // -> 2488970058

// will cast to buffer if given a string, so you can

// directly use foreign characters safely

crc32('自動販売機'); // -> 

// and works in append mode too

const partialCrc = crc32('hey');

const partialCrc = crc32(' ', partialCrc);

const partialCrc = crc32('sup', partialCrc);

const partialCrc = crc32(' ', partialCrc);

const finalCrc = crc32('bros', partialCrc); // -> 

```

# tests

This was tested against the output of zlib's crc32 method. You can run

the tests with`npm test` (requires tap)

# see also

https://github.com/alexgorbatchev/node-crc, `crc.buffer.crc32` also

supports buffer inputs and return unsigned ints (thanks @tjholowaychuk).

# license

MIT/X11