npm package: @stdlib/process-geteuid
Description: Return the effective numeric user identity of a calling process.
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>
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</details>

# geteuid

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

> Return the effective numeric user identity of the calling process.

<section class="installation">

## Installation

```bash
npm install @stdlib/process-geteuid
```

</section>

<section class="usage">

## Usage

```javascript
var geteuid = require( '@stdlib/process-geteuid' );
```

#### geteuid()

Returns the effective numeric user identity of the calling process.

```javascript
var id = geteuid();
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   The function **only** returns an `integer` user identity on POSIX platforms. For all other platforms (e.g., Windows, browsers, and Android), the function returns `null`.
-   See [geteuid(2)][geteuid].

</section>

<section class="examples">

## Examples

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

```javascript
var geteuid = require( '@stdlib/process-geteuid' );

var uid = geteuid();
if ( uid === 0 ) {
    console.log( 'Effectively running as root.' );
} else {
    console.log( 'uid: %d', uid );
}
```

</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/process-getegid`][@stdlib/process/getegid]</span><span class="delimiter">: </span><span class="description">return the effective numeric group identity of a calling process.</span>
-   <span class="package-name">[`@stdlib/process-getgid`][@stdlib/process/getgid]</span><span class="delimiter">: </span><span class="description">return the numeric group identity of a calling process.</span>
-   <span class="package-name">[`@stdlib/process-getuid`][@stdlib/process/getuid]</span><span class="delimiter">: </span><span class="description">return the numeric user identity of a calling process.</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/process-geteuid.svg
[npm-url]: https://npmjs.org/package/@stdlib/process-geteuid

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

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

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/process-geteuid/main/LICENSE

[geteuid]: http://man7.org/linux/man-pages/man2/geteuid.2.html

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

[@stdlib/process/getegid]: https://www.npmjs.com/package/@stdlib/process-getegid

[@stdlib/process/getgid]: https://www.npmjs.com/package/@stdlib/process-getgid

[@stdlib/process/getuid]: https://www.npmjs.com/package/@stdlib/process-getuid

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

</section>

<!-- /.links -->