This is a
playground to test code. It runs a full
Node.js environment and already has all of
npm’s 400,000 packages pre-installed, including
buffer-crc32 with all
npm packages installed. Try it out:
This service is provided by RunKit and is not affiliated with npm, Inc or the package authors.
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
npm install buffer-crc32
var crc32 = require('buffer-crc32'); // works with buffers var buf = Buffer([0x00, 0x73, 0x75, 0x70, 0x20, 0x62, 0x72, 0x6f, 0x00]) crc32(buf) // -> <Buffer 94 5a ab 4a> // 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') // -> <Buffer cb 03 1a c5> // and works in append mode too var partialCrc = crc32('hey'); var partialCrc = crc32(' ', partialCrc); var partialCrc = crc32('sup', partialCrc); var partialCrc = crc32(' ', partialCrc); var finalCrc = crc32('bros', partialCrc); // -> <Buffer 47 fa 55 70>
This was tested against the output of zlib's crc32 method. You can run
the tests with
npm test (requires tap)
supports buffer inputs and return unsigned ints (thanks @tjholowaychuk).