Build CLI utilities effortlessly.
- Adheres POSIX/GNU conventions
- Strict input validation
- Errors are collected into an array
- Subcommand support with infinite nesting
- Subcommands support their own set of options and arguments
- Argument filters that allow for argument validation, type casting, etc.
- Option aliases
- Hooks to simplify handling the help option, version option, and parser errors.
- Built-in TypeScript type declarations
Full API documentation can be found here.
The most relevant parts are:
- getopts() (internally known as
parse()) - ParsedInput - what
getopts()returns.
npm i @prasadrajandran/getoptsconst { getopts } = require('@prasadrajandran/getopts');import { getopts } from '@prasadrajandran/getopts';See this for more info.
import { getopts } from '@prasadrajandran/getopts'; import { Schema, CmdSchema, OptSchema, } from '@prasadrajandran/getopts/dist/interfaces/schema'; import { Config } from '@prasadrajandran/getopts/dist/interfaces/config';TypeScript interfaces can be used too.
const { opts, args, errors } = getopts({ opts: [ { name: ['-l', '--limit'], arg: { required: true, filter: (arg) => parseInt(arg) } }, { name: '--version' }, { name: '--help' }, ], args: { min: 1, max: 1, filter: (arg) => { const filename = path.resolve(arg); if (!fs.lstatSync(filename).isFile()) { throw new Error(`${filename} is not a file`); } return filename; }, }, }); // Note: This behaviour can be simplified by the use of hooks. Have a look at // the CLI config documentation for more info. if (opts.has('--help')) { printHelp(); process.exit(0); } else if (opts.has('--version')) { printVersion(); process.exit(0); } else if (errors.length) { errors.forEach(({ message }) => { console.error(`${packageName}: ${message}`); }); printHelp(); process.exit(1); } // Note: `opts` is an instance of `OptMap` (see API docs). So the line below // could be rewritten like this: // `const limit = opts.get(['-l', '--limit'], Infinity)`; const limit = opts.get('-l') || opts.get('--limit') || Infinity; const filename = args[0]; // Run utility...const { cmds, opts, errors } = getopts({ cmds: [ { name: 'up', opts: [ { name: ['-v', '--verbose'] }, ], args: { max: 0 }, }, { name: 'down', args: { max: 0 }, }, ], opts: [ { name: '--version' }, { name: '--help' }, ], }); const cmd = cmds[0]; switch (cmd) { case 'up': // Note: `opts` is an instance of `OptMap` (see API docs) so `opts.has()` // can also accept an array of option names. const verbose = opts.has(['-v', '--verbose']); // up... break; case 'down': // down... break; }