yargs/README.md

<p align="center">
  <img width="250" src="/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>

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## 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.

> <img width="400" src="/screen.png">

* 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 argv = require('yargs').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!
```

### Complex Example

```javascript
#!/usr/bin/env node
require('yargs') // eslint-disable-line
  .command('serve [port]', 'start the server', (yargs) => {
    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'
  })
  .argv
```

Run the example above with `--help` to see the help for the application.

## TypeScript

yargs has type definitions at [@types/yargs][type-definitions].

```
npm i @types/yargs --save-dev
```

See usage examples in [docs](/docs/typescript.md).

## Webpack

See usage examples of yargs with webpack in [docs](/docs/webpack.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)
* [Contributing](/contributing.md)

[travis-url]: https://travis-ci.org/yargs/yargs
[travis-image]: https://img.shields.io/travis/yargs/yargs/master.svg
[coveralls-url]: https://coveralls.io/github/yargs/yargs
[coveralls-image]: https://img.shields.io/coveralls/yargs/yargs.svg
[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