# clap > Command line argument parser Latest version **3.1.1** (published 2022-02-07) · MIT license · 0 weekly downloads ## Install ```sh npm install clap pnpm add clap yarn add clap bun add clap ``` ## Health **Score 20/100 (F)** — status: abandoned. Positive: esm support; no vulnerabilities. Warnings: low downloads; no types. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 3.1.1 | | Published | 2022-02-07 | | First published | 2014-02-10 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | none | | Module format | ESM + CommonJS | | Node | ^12.20.0 \|\| ^14.13.0 \|\| >=15.0.0 | | Dependencies | 1 | | Unpacked size | 46.2 KB | | Known vulnerabilities | 0 | | Install scripts | no | | Author | Roman Dvornov | | Maintainers | lahmatiy | | Keywords | cli, command, option, argument, completion | ## Links - npm: https://www.npmjs.com/package/clap - Repository: https://github.com/lahmatiy/clap - Homepage: https://github.com/lahmatiy/clap#readme - Issues: https://github.com/lahmatiy/clap/issues - npm.io page: https://npm.io/package/clap ## Dependencies (1) - [ansi-colors](https://npm.io/package/ansi-colors.md) ^4.1.1 ## Alternatives - [@salesforce/cli](https://npm.io/package/@salesforce/cli.md) — 389.7K weekly downloads - [@mintlify/cli](https://npm.io/package/@mintlify/cli.md) — 208.9K weekly downloads - [@grafana/e2e-selectors](https://npm.io/package/@grafana/e2e-selectors.md) — 128.7K weekly downloads - [mintlify](https://npm.io/package/mintlify.md) — 112.0K weekly downloads - [@intlayer/cli](https://npm.io/package/@intlayer/cli.md) — 22.8K weekly downloads ## Recent versions - 3.1.1 (latest) — 2022-02-07 - 3.1.0 — 2022-02-07 - 3.0.0 — 2021-12-12 - 3.0.0-beta.1 — 2020-02-14 - 2.0.1 — 2019-12-16 - 2.0.0 — 2019-12-09 - 1.2.3 — 2017-09-20 - 1.2.2 — 2017-09-18 - 1.2.1 — 2017-09-18 - 1.2.0 — 2017-06-13 - 1.1.3 — 2017-03-16 - 1.1.2 — 2016-12-03 - 1.1.1 — 2016-05-10 - 1.1.0 — 2016-03-19 - 1.0.10 — 2015-12-16 - … 14 more at https://npm.io/package/clap/versions ## README [![NPM version](https://img.shields.io/npm/v/clap.svg)](https://www.npmjs.com/package/clap) [![Build Status](https://github.com/lahmatiy/clap/actions/workflows/build.yml/badge.svg)](https://github.com/lahmatiy/clap/actions/workflows/build.yml) [![Coverage Status](https://coveralls.io/repos/github/lahmatiy/clap/badge.svg?branch=master)](https://coveralls.io/github/lahmatiy/clap?branch=master) # Clap.js A library for node.js to build command-line interfaces (CLI). With its help, making a simple CLI application is a trivial task. It equally excels in complex tools with a lot of subcommands and specific features. This library supports argument coercion and completion suggestion — typing the commands is much easier. Inspired by [commander.js](https://github.com/tj/commander.js) Features: - TBD ## Usage ``` npm install clap ``` ```js const cli = require('clap'); const myCommand = cli.command('my-command [optional-arg]') .description('Optional description') .version('1.2.3') .option('-b, --bool', 'Bollean option') .option('--foo ', 'Option with required argument') .option('--bar [bar]', 'Option with optional argument') .option('--baz [value]', 'Option with optional argument and normalize function', value => Number(value), 123 // 123 is default ) .action(function({ options, args, literalArgs }) { // options is an object with collected values // args goes before options // literal args goes after "--" }); myCommand.run(); // the same as "myCommnad.run(process.argv.slice(2))" myCommand.run(['--foo', '123', '-b']) // sub-commands myCommand .command('nested') .option('-q, --quz', 'Some parameter', 'Default value') // ... .end() .command('another-command [arg1] [arg2]') // ... .command('level3-command') //... ``` ## API ### Command ``` .command() // definition .description(value) .version(value, usage, description, action) .help(usage, description, action) .option(usage, description, ...options) .command(usageOrCommand) .extend(fn, ...options) .end() // argv processing pipeline handler setters .init(command, context) .applyConfig(context) .prerareContenxt(context) .action(context) // main methods .parse(argv, suggest) .run(argv) // misc .clone(deep) .createOptionValues() .getCommand(name) .getCommands() .getOption(name) .getOptions() .outputHelp() ``` ### .option(usage, description, ...options) There are two usage: ``` .option(usage, description, normalize, value) .option(usage, description, options) ``` Where `options`: ``` { default: any, // default value normalize: (value, oldValue) => { ... }, // any value for option is passing through this function and its result stores as option value shortcut: (value, oldValue) => { ... }, // for shortcut options, the handler is executed after the value is set, and its result (an object) is used as a source of values for other options action: () => { ... }, // for an action option, which breaks regular args processing and preform and action (e.g. show help or version) config: boolean // mark option is about config and should be applied before `applyConfig()` } ``` ### Argv processing - `init(command, context)` // before arguments parsing - invoke action option and exit if any - apply **config** options - `applyConfig(context)` - apply all the rest options - `prepareContext(context)` // after arguments parsing - switch to next command -> command is prescending - `init(command, context)` - invoke action option and exit if any - apply **config** options - `applyConfig(context)` - apply all the rest options - `prepareContext(context)` // after arguments parsing - switch to next command - ... - `action(context)` -> command is target - `action(context)` -> command is target ## License MIT --- _Source: https://npm.io/package/clap · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._