npm package: @stdlib/assert-is-gzip-buffer
Description: Test if a value is a gzip buffer.
Author: The Stdlib Authors
Latest version: 0.2.3

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<details>
  <summary>
    About stdlib...
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# isgzipBuffer

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Test if a value is a [gzip][gzip-rfc-1952] buffer.

<section class="installation">

## Installation

```bash
npm install @stdlib/assert-is-gzip-buffer
```

</section>

<section class="usage">

## Usage

```javascript
var isgzipBuffer = require( '@stdlib/assert-is-gzip-buffer' );
```

#### isgzipBuffer( value )

Tests if a value is a [`gzip`][gzip-rfc-1952] buffer.

```javascript
var Uint8Array = require( '@stdlib/array-uint8' );

var buf = new Uint8Array( 20 );
buf[ 0 ] = 31;  // 0x1f => magic number
buf[ 1 ] = 139; // 0x8b
buf[ 2 ] = 8;   // 0x08 => compression method

var bool = isgzipBuffer( buf );
// returns true

bool = isgzipBuffer( [] );
// returns false
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   A [gzip][gzip-rfc-1952] buffer is defined as either a Node.js [`Buffer`][@stdlib/buffer/ctor] or [`Uint8Array`][@stdlib/array/uint8] which contains a 10-byte header, a body containing the compressed payload, and an 8-byte footer containing a CRC-32 checksum and the length of the original uncompressed data, modulo `2^32`.
-   This function only examines the 10-byte header to ensure the header includes the expected magic number and compression method. The function does not perform an integrity check.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var Float32Array = require( '@stdlib/array-float32' );
var Float64Array = require( '@stdlib/array-float64' );
var Int8Array = require( '@stdlib/array-int8' );
var Int16Array = require( '@stdlib/array-int16' );
var Int32Array = require( '@stdlib/array-int32' );
var Uint8Array = require( '@stdlib/array-uint8' );
var Uint8ClampedArray = require( '@stdlib/array-uint8c' );
var Uint16Array = require( '@stdlib/array-uint16' );
var Uint32Array = require( '@stdlib/array-uint32' );
var isgzipBuffer = require( '@stdlib/assert-is-gzip-buffer' );

var buf = new Uint8Array( 20 );
buf[ 0 ] = 31;  // 0x1f => magic number
buf[ 1 ] = 139; // 0x8b
buf[ 2 ] = 8;   // 0x08 => compression method

var bool = isgzipBuffer( buf );
// returns true

bool = isgzipBuffer( new Float32Array( 20 ) );
// returns false

bool = isgzipBuffer( new Int8Array( 20 ) );
// returns false

bool = isgzipBuffer( new Uint8Array( 20 ) );
// returns false

bool = isgzipBuffer( new Uint8ClampedArray( 20 ) );
// returns false

bool = isgzipBuffer( new Int16Array( 20 ) );
// returns false

bool = isgzipBuffer( new Uint16Array( 20 ) );
// returns false

bool = isgzipBuffer( new Int32Array( 20 ) );
// returns false

bool = isgzipBuffer( new Uint32Array( 20 ) );
// returns false

bool = isgzipBuffer( new Float64Array( 20 ) );
// returns false

bool = isgzipBuffer( new Array( 20 ) );
// returns false

bool = isgzipBuffer( {} );
// returns false

bool = isgzipBuffer( null );
// returns false
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/assert-is-buffer`][@stdlib/assert/is-buffer]</span><span class="delimiter">: </span><span class="description">test if a value is a Buffer object.</span>
-   <span class="package-name">[`@stdlib/assert-is-uint8array`][@stdlib/assert/is-uint8array]</span><span class="delimiter">: </span><span class="description">test if a value is a Uint8Array.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->


<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/assert-is-gzip-buffer.svg
[npm-url]: https://npmjs.org/package/@stdlib/assert-is-gzip-buffer

[test-image]: https://github.com/stdlib-js/assert-is-gzip-buffer/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/assert-is-gzip-buffer/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/assert-is-gzip-buffer/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/assert-is-gzip-buffer?branch=main

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[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/assert-is-gzip-buffer/tree/deno
[deno-readme]: https://github.com/stdlib-js/assert-is-gzip-buffer/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/assert-is-gzip-buffer/tree/umd
[umd-readme]: https://github.com/stdlib-js/assert-is-gzip-buffer/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/assert-is-gzip-buffer/tree/esm
[esm-readme]: https://github.com/stdlib-js/assert-is-gzip-buffer/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/assert-is-gzip-buffer/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/assert-is-gzip-buffer/main/LICENSE

[gzip-rfc-1952]: https://tools.ietf.org/html/rfc1952

[@stdlib/buffer/ctor]: https://www.npmjs.com/package/@stdlib/buffer-ctor

[@stdlib/array/uint8]: https://www.npmjs.com/package/@stdlib/array-uint8

<!-- <related-links> -->

[@stdlib/assert/is-buffer]: https://www.npmjs.com/package/@stdlib/assert-is-buffer

[@stdlib/assert/is-uint8array]: https://www.npmjs.com/package/@stdlib/assert-is-uint8array

<!-- </related-links> -->

</section>

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