| <p align="center"> |
| <img width="250" src="https://raw.githubusercontent.com/yargs/yargs/main/yargs-logo.png"> |
| </p> |
| <h1 align="center"> Yargs </h1> |
| <p align="center"> |
| <b >Yargs be a node.js library fer hearties tryin' ter parse optstrings</b> |
| </p> |
| |
| <br> |
| |
|  |
| [![NPM version][npm-image]][npm-url] |
| [![js-standard-style][standard-image]][standard-url] |
| [![Coverage][coverage-image]][coverage-url] |
| [![Conventional Commits][conventional-commits-image]][conventional-commits-url] |
| [![Slack][slack-image]][slack-url] |
| |
| ## Description |
| Yargs helps you build interactive command line tools, by parsing arguments and generating an elegant user interface. |
| |
| It gives you: |
| |
| * commands and (grouped) options (`my-program.js serve --port=5000`). |
| * a dynamically generated help menu based on your arguments: |
| |
| ``` |
| mocha [spec..] |
| |
| Run tests with Mocha |
| |
| Commands |
| mocha inspect [spec..] Run tests with Mocha [default] |
| mocha init <path> create a client-side Mocha setup at <path> |
| |
| Rules & Behavior |
| --allow-uncaught Allow uncaught errors to propagate [boolean] |
| --async-only, -A Require all tests to use a callback (async) or |
| return a Promise [boolean] |
| ``` |
| |
| * bash-completion shortcuts for commands and options. |
| * and [tons more](/docs/api.md). |
| |
| ## Installation |
| |
| Stable version: |
| ```bash |
| npm i yargs |
| ``` |
| |
| Bleeding edge version with the most recent features: |
| ```bash |
| npm i yargs@next |
| ``` |
| |
| ## Usage |
| |
| ### Simple Example |
| |
| ```javascript |
| #!/usr/bin/env node |
| const yargs = require('yargs/yargs') |
| const { hideBin } = require('yargs/helpers') |
| const argv = yargs(hideBin(process.argv)).argv |
| |
| if (argv.ships > 3 && argv.distance < 53.5) { |
| console.log('Plunder more riffiwobbles!') |
| } else { |
| console.log('Retreat from the xupptumblers!') |
| } |
| ``` |
| |
| ```bash |
| $ ./plunder.js --ships=4 --distance=22 |
| Plunder more riffiwobbles! |
| |
| $ ./plunder.js --ships 12 --distance 98.7 |
| Retreat from the xupptumblers! |
| ``` |
| |
| > Note: `hideBin` is a shorthand for [`process.argv.slice(2)`](https://nodejs.org/en/knowledge/command-line/how-to-parse-command-line-arguments/). It has the benefit that it takes into account variations in some environments, e.g., [Electron](https://github.com/electron/electron/issues/4690). |
| |
| ### Complex Example |
| |
| ```javascript |
| #!/usr/bin/env node |
| const yargs = require('yargs/yargs') |
| const { hideBin } = require('yargs/helpers') |
| |
| yargs(hideBin(process.argv)) |
| .command('serve [port]', 'start the server', (yargs) => { |
| return yargs |
| .positional('port', { |
| describe: 'port to bind on', |
| default: 5000 |
| }) |
| }, (argv) => { |
| if (argv.verbose) console.info(`start server on :${argv.port}`) |
| serve(argv.port) |
| }) |
| .option('verbose', { |
| alias: 'v', |
| type: 'boolean', |
| description: 'Run with verbose logging' |
| }) |
| .parse() |
| ``` |
| |
| Run the example above with `--help` to see the help for the application. |
| |
| ## Supported Platforms |
| |
| ### TypeScript |
| |
| yargs has type definitions at [@types/yargs][type-definitions]. |
| |
| ``` |
| npm i @types/yargs --save-dev |
| ``` |
| |
| See usage examples in [docs](/docs/typescript.md). |
| |
| ### Deno |
| |
| As of `v16`, `yargs` supports [Deno](https://github.com/denoland/deno): |
| |
| ```typescript |
| import yargs from 'https://deno.land/x/yargs/deno.ts' |
| import { Arguments } from 'https://deno.land/x/yargs/deno-types.ts' |
| |
| yargs(Deno.args) |
| .command('download <files...>', 'download a list of files', (yargs: any) => { |
| return yargs.positional('files', { |
| describe: 'a list of files to do something with' |
| }) |
| }, (argv: Arguments) => { |
| console.info(argv) |
| }) |
| .strictCommands() |
| .demandCommand(1) |
| .parse() |
| ``` |
| |
| ### ESM |
| |
| As of `v16`,`yargs` supports ESM imports: |
| |
| ```js |
| import yargs from 'yargs' |
| import { hideBin } from 'yargs/helpers' |
| |
| yargs(hideBin(process.argv)) |
| .command('curl <url>', 'fetch the contents of the URL', () => {}, (argv) => { |
| console.info(argv) |
| }) |
| .demandCommand(1) |
| .parse() |
| ``` |
| |
| ### Usage in Browser |
| |
| See examples of using yargs in the browser in [docs](/docs/browser.md). |
| |
| ## Community |
| |
| Having problems? want to contribute? join our [community slack](http://devtoolscommunity.herokuapp.com). |
| |
| ## Documentation |
| |
| ### Table of Contents |
| |
| * [Yargs' API](/docs/api.md) |
| * [Examples](/docs/examples.md) |
| * [Parsing Tricks](/docs/tricks.md) |
| * [Stop the Parser](/docs/tricks.md#stop) |
| * [Negating Boolean Arguments](/docs/tricks.md#negate) |
| * [Numbers](/docs/tricks.md#numbers) |
| * [Arrays](/docs/tricks.md#arrays) |
| * [Objects](/docs/tricks.md#objects) |
| * [Quotes](/docs/tricks.md#quotes) |
| * [Advanced Topics](/docs/advanced.md) |
| * [Composing Your App Using Commands](/docs/advanced.md#commands) |
| * [Building Configurable CLI Apps](/docs/advanced.md#configuration) |
| * [Customizing Yargs' Parser](/docs/advanced.md#customizing) |
| * [Bundling yargs](/docs/bundling.md) |
| * [Contributing](/contributing.md) |
| |
| ## Supported Node.js Versions |
| |
| Libraries in this ecosystem make a best effort to track |
| [Node.js' release schedule](https://nodejs.org/en/about/releases/). Here's [a |
| post on why we think this is important](https://medium.com/the-node-js-collection/maintainers-should-consider-following-node-js-release-schedule-ab08ed4de71a). |
| |
| [npm-url]: https://www.npmjs.com/package/yargs |
| [npm-image]: https://img.shields.io/npm/v/yargs.svg |
| [standard-image]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg |
| [standard-url]: http://standardjs.com/ |
| [conventional-commits-image]: https://img.shields.io/badge/Conventional%20Commits-1.0.0-yellow.svg |
| [conventional-commits-url]: https://conventionalcommits.org/ |
| [slack-image]: http://devtoolscommunity.herokuapp.com/badge.svg |
| [slack-url]: http://devtoolscommunity.herokuapp.com |
| [type-definitions]: https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/yargs |
| [coverage-image]: https://img.shields.io/nycrc/yargs/yargs |
| [coverage-url]: https://github.com/yargs/yargs/blob/main/.nycrc |