What is crc?
The crc npm package is used for generating cyclic redundancy check (CRC) codes for various input data. CRC is a popular method for detecting accidental changes to raw data in digital networks and storage devices. The package supports multiple CRC algorithms and can be used in various applications where data integrity is crucial.
What are crc's main functionalities?
CRC32 Calculation
This feature allows the calculation of CRC32 checksum for the input string 'hello world'. It is useful for verifying the integrity of strings or files.
const crc = require('crc');
const result = crc.crc32('hello world');
console.log('CRC32:', result);
CRC16 Calculation
This feature computes the CRC16 checksum for the given string. It's commonly used in telecommunications and storage for error-checking.
const crc = require('crc');
const result = crc.crc16('hello world');
console.log('CRC16:', result);
CRC1 Calculation
This feature calculates a simple CRC1 checksum, which can be used for basic error detection in scenarios where minimal data corruption checks are needed.
const crc = require('crc');
const result = crc.crc1('hello world');
console.log('CRC1:', result);
Other packages similar to crc
crc32
The crc32 package is similar to crc in that it provides CRC32 checksum calculations. However, it focuses solely on CRC32, whereas crc supports multiple algorithms including CRC1, CRC8, CRC16, and others, making crc more versatile.
buffer-crc32
buffer-crc32 is another npm package that offers CRC32 checksum calculations. It is designed to work specifically with Node.js buffers. Compared to crc, buffer-crc32 is more specialized for buffer data types while crc offers broader functionality with support for strings and other data types.
crc
Module for calculating Cyclic Redundancy Check (CRC) for Node.js and the Browser.
Important: Node >= 6.3.0 < 6.9.2
There's was a bug in Node #9342 that affected CRC calculation if Buffer.split()
is used (see issue discussion for details). This affected all version starting from 6.3.0
up to but not including 6.9.2
. The patch #9341 was released in 6.9.2
. If you are upgrading and seeing odd CRC calculation mismatches, this might be the reason.
Features
- Full test suite comparing values against reference
pycrc
implementation. - Pure JavaScript implementation, no dependencies.
- Provides CRC tables for optimized calculations.
- Provides support for the following CRC algorithms:
- CRC1
crc.crc1(…)
- CRC8
crc.crc8(…)
- CRC8 1-Wire
crc.crc81wire(…)
- CRC16
crc.crc16(…)
- CRC16 CCITT
crc.crc16ccitt(…)
- CRC16 Modbus
crc.crc16modbus(…)
- CRC16 Kermit
crc.crc16kermit(…)
- CRC16 XModem
crc.crc16xmodem(…)
- CRC24
crc.crc24(…)
- CRC32
crc.crc32(…)
- CRCJAM
crc.crcjam(…)
Installation
npm install crc
Usage
Calculate a CRC32:
const crc = require('crc');
crc.crc32('hello').toString(16);
Calculate a CRC32 of a file:
crc.crc32(fs.readFileSync('README.md', 'utf8')).toString(16);
Or using a Buffer
:
crc.crc32(fs.readFileSync('README.md')).toString(16);
Incrementally calculate a CRC32:
value = crc.crc32('one');
value = crc.crc32('two', value);
value = crc.crc32('three', value);
value.toString(16);
For web distribution, it's best to require specific modules that you need to avoid bundling unnecessary code.
const crc32 = require('crc/lib/crc32');
crc32('hello').toString(16);
Running tests
npm test
Thanks!
pycrc library is which the source of all of the CRC tables.
License
The MIT License (MIT)
Copyright (c) 2014 Alex Gorbatchev
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.