| # 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 |