meow

CLI app helper

Features

• Parses arguments using minimist
• Converts flags to camelCase
• Outputs version when --version
• Outputs description and supplied help text when --help
• Makes unhandled rejected promises fail loudly instead of the default silent fail
• Sets the process title to the binary name defined in package.json

Install

$ npm install --save meow

Usage

$ ./foo-app.js unicorns --rainbow-cake

#!/usr/bin/env node
'use strict';
const meow = require('meow');
const foo = require('./');
 
const cli = meow(`
    Usage
      $ foo <input>
 
    Options
      -r, --rainbow  Include a rainbow
 
    Examples
      $ foo unicorns --rainbow
      🌈 unicorns 🌈
`, {
    alias: {
        r: 'rainbow'
    }
});
/*
{
    input: ['unicorns'],
    flags: {rainbow: true},
    ...
}
*/
 
foo(cli.input[0], cli.flags);

API

meow(options, [minimistOptions])

Returns an object with:

• input (array) - Non-flag arguments
• flags (object) - Flags converted to camelCase
• pkg (object) - The package.json object
• help (object) - The help text used with --help
• showHelp([code=0]) (function) - Show the help text and exit with code

options

Type: object, array, string

Can either be a string/array that is the help or an options object.

description

Type: string, boolean Default: The package.json "description" property

A description to show above the help text.

Set it to false to disable it altogether.

help

Type: string, boolean

The help text you want shown.

The input is reindented and starting/ending newlines are trimmed which means you can use a template literal without having to care about using the correct amount of indent.

If it's an array each item will be a line.
(Still supported, but you should use a template literal instead.)

The description will be shown above your help text automatically.

Set it to false to disable it altogether.

version

Type: string, boolean
Default: The package.json "version" property

Set a custom version output.

Set it to false to disable it altogether.

pkg

Type: string, object
Default: Closest package.json upwards

Relative path to package.json or as an object.

argv

Type: array
Default: process.argv.slice(2)

Custom arguments object.

minimistOptions

Type: object
Default: {}

Minimist options.

Keys passed to the minimist default option are decamelized, so you can for example pass in fooBar: 'baz' and have it be the default for the --foo-bar flag.

Promises

Meow will make unhandled rejected promises fail loudly instead of the default silent fail. Meaning you don't have to manually .catch() promises used in your CLI.

Tips

See chalk if you want to colorize the terminal output.

See get-stdin if you want to accept input from stdin.

See update-notifier if you want update notifications.

See configstore if you need to persist some data.

More useful CLI utilities.

License

MIT © Sindre Sorhus