## Usage ```javascript var readFile = require( '@stdlib/fs-read-file' ); ``` #### readFile( file\[, options], clbk ) Asynchronously reads the entire contents of a file. ```javascript readFile( __filename, onFile ); function onFile( error, data ) { if ( error ) { throw error; } console.log( data ); } ``` The function accepts the same `options` and has the same defaults as [`fs.readFile()`][node-fs]. #### readFile.sync( file\[, options] ) Synchronously reads the entire contents of a `file`. ```javascript var out = readFile.sync( __filename ); if ( out instanceof Error ) { throw out; } console.log( out ); ``` The function accepts the same `options` and has the same defaults as [`fs.readFileSync()`][node-fs].

## Notes - The difference between this API and [`fs.readFileSync()`][node-fs] is that [`fs.readFileSync()`][node-fs] will throw if an `error` is encountered (e.g., if given a non-existent `path`) and this API will return an `error`. Hence, the following anti-pattern ```javascript var fs = require( 'fs' ); var file = '/path/to/file.js'; // Check for existence to prevent an error being thrown... if ( fs.existsSync( file ) ) { file = fs.readFileSync( file ); } ``` can be replaced by an approach which addresses existence via `error` handling. ```javascript var readFile = require( '@stdlib/fs-read-file' ); var file = '/path/to/file.js'; // Explicitly handle the error... file = readFile.sync( file ); if ( file instanceof Error ) { // You choose what to do... console.error( file.message ); } ```

## Examples ```javascript var readFile = require( '@stdlib/fs-read-file' ); /* Sync */ var file = readFile.sync( __filename, 'utf8' ); // returns console.log( file instanceof Error ); // => false file = readFile.sync( 'beepboop', { 'encoding': 'utf8' }); // returns console.log( file instanceof Error ); // => true /* Async */ readFile( __filename, onFile ); readFile( 'beepboop', onFile ); function onFile( error, data ) { if ( error ) { if ( error.code === 'ENOENT' ) { console.error( 'File does not exist.' ); } else { throw error; } } else { console.log( data ); } } ```

## CLI

## Installation To use the module as a general utility, install the module globally ```bash npm install -g @stdlib/fs-read-file ```

### Usage ```text Usage: read-file [options] Options: -h, --help Print this message. -V, --version Print the package version. --enc, --encoding encoding Encoding. --flag flag Flag. Default: 'r'. ```

### Notes - Relative file paths are resolved relative to the current working directory. - Errors are written to `stderr`. - File contents are written to `stdout`.

### Examples ```bash $ read-file ./README.md ```

* * * ## 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 © 2016-2022. The Stdlib [Authors][stdlib-authors].

[npm-image]: http://img.shields.io/npm/v/@stdlib/fs-read-file.svg [npm-url]: https://npmjs.org/package/@stdlib/fs-read-file [test-image]: https://github.com/stdlib-js/fs-read-file/actions/workflows/test.yml/badge.svg [test-url]: https://github.com/stdlib-js/fs-read-file/actions/workflows/test.yml [coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/fs-read-file/main.svg [coverage-url]: https://codecov.io/github/stdlib-js/fs-read-file?branch=main [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-read-file/tree/deno [umd-url]: https://github.com/stdlib-js/fs-read-file/tree/umd [esm-url]: https://github.com/stdlib-js/fs-read-file/tree/esm [chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg [chat-url]: https://gitter.im/stdlib-js/stdlib/ [stdlib]: https://github.com/stdlib-js/stdlib [stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors [stdlib-license]: https://raw.githubusercontent.com/stdlib-js/fs-read-file/main/LICENSE [node-fs]: https://nodejs.org/api/fs.html [@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-dir]: https://www.npmjs.com/package/@stdlib/fs-read-dir [@stdlib/fs/read-json]: https://www.npmjs.com/package/@stdlib/fs-read-json [@stdlib/fs/write-file]: https://www.npmjs.com/package/@stdlib/fs-write-file