You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
48 lines
1.4 KiB
48 lines
1.4 KiB
3 years ago
|
# buffer-crc32
|
||
|
|
|
||
|
|
[](http://travis-ci.org/brianloveswords/buffer-crc32)
|
||
|
|
|
||
|
|
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
|
||
|
|
|
||
|
|
# install
|
||
|
|
```
|
||
|
|
npm install buffer-crc32
|
||
|
|
```
|
||
|
|
|
||
|
|
# example
|
||
|
|
```js
|
||
|
|
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>
|
||
|
|
```
|
||
|
|
|
||
|
|
# 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
|