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# crc32-stream v2.0.0 [](https://travis-ci.org/archiverjs/node-crc32-stream) [](https://ci.appveyor.com/project/ctalkington/node-crc32-stream/branch/master)
crc32-stream is a streaming CRC32 checksumer. It uses [buffer-crc32](https://www.npmjs.org/package/buffer-crc32) behind the scenes to reliably handle binary data and fancy character sets. Data is passed through untouched.
### Install
```bash
npm install crc32-stream --save
```
You can also use `npm install https://github.com/archiverjs/node-crc32-stream/archive/master.tar.gz` to test upcoming versions.
### Usage
#### CRC32Stream
Inherits [Transform Stream](http://nodejs.org/api/stream.html#stream_class_stream_transform) options and methods.
```js
var CRC32Stream = require('crc32-stream');
var source = fs.createReadStream('file.txt');
var checksum = new CRC32Stream();
checksum.on('end', function(err) {
// do something with checksum.digest() here
});
// either pipe it
source.pipe(checksum);
// or write it
checksum.write('string');
checksum.end();
```
#### DeflateCRC32Stream
Inherits [zlib.DeflateRaw](http://nodejs.org/api/zlib.html#zlib_class_zlib_deflateraw) options and methods.
```js
var DeflateCRC32Stream = require('crc32-stream').DeflateCRC32Stream;
var source = fs.createReadStream('file.txt');
var checksum = new DeflateCRC32Stream();
checksum.on('end', function(err) {
// do something with checksum.digest() here
});
// either pipe it
source.pipe(checksum);
// or write it
checksum.write('string');
checksum.end();
```
### Instance API
#### digest()
Returns the checksum digest in unsigned form.
#### hex()
Returns the hexadecimal representation of the checksum digest. (ie E81722F0)
#### size(compressed)
Returns the raw size/length of passed-through data.
If `compressed` is `true`, it returns compressed length instead. (DeflateCRC32Stream)
## Things of Interest
- [Changelog](https://github.com/archiverjs/node-crc32-stream/releases)
- [Contributing](https://github.com/archiverjs/node-crc32-stream/blob/master/CONTRIBUTING.md)
- [MIT License](https://github.com/archiverjs/node-crc32-stream/blob/master/LICENSE-MIT)
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