<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>
!ci
[![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.
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:hideBinis a shorthand forprocess.argv.slice(2). It has the benefit that it takes into account variations in some environments, e.g., Electron.
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.
Deno
As of v16, yargs supports 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.
Community
Having problems? want to contribute? join our community slack.
Documentation
Table of Contents
* Numbers
* Arrays
* Objects
* Quotes
* Composing Your App Using Commands
* Building Configurable CLI Apps
Supported Node.js Versions
Libraries in this ecosystem make a best effort to track
Node.js' release schedule. 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