npm package: @stdlib/fs-close
Description: Close a file descriptor.
Author: The Stdlib Authors
Latest version: 0.2.3

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<details>
  <summary>
    About stdlib...
  </summary>
  <p>We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.</p>
  <p>The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.</p>
  <p>When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.</p>
  <p>To join us in bringing numerical computing to the web, get started by checking us out on <a href="https://github.com/stdlib-js/stdlib">GitHub</a>, and please consider <a href="https://opencollective.com/stdlib">financially supporting stdlib</a>. We greatly appreciate your continued support!</p>
</details>

# Close

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

> Close a file descriptor.

<section class="installation">

## Installation

```bash
npm install @stdlib/fs-close
```

</section>

<section class="usage">

## Usage

<!-- eslint-disable stdlib/no-redeclare -->

```javascript
var close = require( '@stdlib/fs-close' );
```

#### close( fd, clbk )

Asynchronously closes a file descriptor, so that the file descriptor no longer refers to any file and may be reused.

<!-- eslint-disable stdlib/no-redeclare -->

```javascript
var openSync = require( '@stdlib/fs-open' ).sync;

var fd = openSync( __filename );
close( fd, done );

function done( error ) {
    if ( error ) {
        throw error;
    }
}
```

#### close.sync( fd )

Synchronously closes a file descriptor.

<!-- eslint-disable stdlib/no-redeclare -->

```javascript
var openSync = require( '@stdlib/fs-open' ).sync;

var fd = openSync( __filename );

var err = close.sync( fd );
if ( err instanceof Error ) {
    throw err;
}
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   The difference between this API and [`fs.closeSync()`][node-fs] is that [`fs.closeSync()`][node-fs] will throw if an `error` is encountered (e.g., if given an invalid file descriptor) and this API will return an `error`.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint-disable stdlib/no-redeclare -->

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

```javascript
var join = require( 'path' ).join;
var openSync = require( '@stdlib/fs-open' ).sync;
var close = require( '@stdlib/fs-close' );

var err;

/* Sync */

var fd = openSync( join( __dirname, 'package.json' ), 'r+' );
if ( fd instanceof Error ) {
    console.error( fd.message );
} else {
    err = close.sync( fd );
    // returns undefined

    if ( err instanceof Error ) {
        console.error( err.message );
    } else {
        console.log( 'Synchronously closed file descriptor.' );
    }
}

/* Async */

fd = openSync( join( __dirname, 'package.json' ), 'r+' );
if ( fd instanceof Error ) {
    console.error( fd.message );
} else {
    close( fd, done );
}

function done( error ) {
    if ( error ) {
        console.error( error.message );
    } else {
        console.log( 'Asynchronously closed file descriptor.' );
    }
}
```

</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/fs-exists`][@stdlib/fs/exists]</span><span class="delimiter">: </span><span class="description">test whether a path exists on the filesystem.</span>
-   <span class="package-name">[`@stdlib/fs-open`][@stdlib/fs/open]</span><span class="delimiter">: </span><span class="description">open a file.</span>
-   <span class="package-name">[`@stdlib/fs-read-file`][@stdlib/fs/read-file]</span><span class="delimiter">: </span><span class="description">read the entire contents of a file.</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 -->

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

<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/fs-close.svg
[npm-url]: https://npmjs.org/package/@stdlib/fs-close

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

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/fs-close/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/fs-close?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/fs-close/tree/deno
[deno-readme]: https://github.com/stdlib-js/fs-close/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/fs-close/tree/umd
[umd-readme]: https://github.com/stdlib-js/fs-close/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/fs-close/tree/esm
[esm-readme]: https://github.com/stdlib-js/fs-close/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/fs-close/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/fs-close/main/LICENSE

[node-fs]: https://nodejs.org/api/fs.html

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

[@stdlib/fs/exists]: https://www.npmjs.com/package/@stdlib/fs-exists

[@stdlib/fs/open]: https://www.npmjs.com/package/@stdlib/fs-open

[@stdlib/fs/read-file]: https://www.npmjs.com/package/@stdlib/fs-read-file

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

</section>

<!-- /.links -->