opts.js

Find the full documentation, source code, and examples online at https://khtdr.com/opts.

Or download this README as a man-page.

curl -o opts.3 https://raw.githubusercontent.com/khtdr/opts/master/man.3
man ./opts.3

NAME

opts.js - a command line parser for options and arguments

SYNOPSIS

The following example uses a custom version function, and opts in to the automatic help text. No pun intended.

var opts = require('opts');

var options = [
  { short       : 'v'
  , long        : 'version'
  , description : 'Show version and exit'
  , callback    : function () { console.log('v1.0'); process.exit(1); }
  }
];

opts.parse(options, true);
console.log('Example 1');
process.exit(0);

See https://raw.githubusercontent.com/khtdr/opts/master/examples/example1.js

running:

$ node ./example1

produces:

Example 1

running:

$ node ./example1 --help

produces:

Usage: node ./example1 [options]
Show this help message
   --help
Show version and exit
   -v, --version

running:

node ./example1 -v

produces:

v1.0

INSTALLATION

You do not need to use NPM or any package manager. It is written in plain-old Javascript and can be downloaded and included in your Node.js project, as-is. All of the examples use this approach. .RE See https://github.com/khtdr/opts/tree/master/examples

Stand-alone version

cd /path/to/your/project
curl -o opts.js https://raw.githubusercontent.com/khtdr/opts/master/src/opts.js

NPM version

npm install opts

USAGE

LOADING

With classic syntax:

var opts = require('opts');
opts.parse(options, arguments, help);

With modern syntax:

import * as opts from 'opts';
opts.parse(options, arguments, help);

If you installed opts with NPM, the typescript definitions should automatically be available in your editor. Otherwise you can download the .d.ts file manually. .RE See https://raw.githubusercontent.com/khtdr/opts/master/src/opts.d.ts

CONFIGURING

opts.parse(options, arguments, help)

Options are flag-arguments. Arguments are everything else. Consider the following hypothetical command for starting a server that listens on http://0.0.0.0:4000

node ./my-app start --host 0.0.0.0 -p 4000

In this example, the options are --host 0.0.0.0 and -p 4000. The argument is start. The arguments can be after, before, or among the options.

options

options is an array of option objects. Each option in the array can have the following fields. None are required, but you should at least provide a short or long name.

let options = [
  { short       : 'l',
    long        : 'list',
    description : 'Show a list',
    value       : false, // default false
    required    : true, // default false
    callback    : function (value) { ... },
  }, // ... followed by more options
];

arguments

arguments require less configuration. This is an optional argument to opts.parse:

let arguments = [
    { name     : 'script',
      required : true, // not required by default
      callback : function (value) { ... },
    };
  ]

help text generator

Finally, you can add an automatically generated help message by passing a last parameter of true. This is also an optional argument to opts.parse.

opts.parse(options, true);
// or if you want more control, you can do:
/*
  options.push({
    long        : 'help',
    description : 'Show this help message',
    callback    : require('opts').help,
  }
  opts.parse(options);
*/

AUTHOR / CHANGELOG / LICENSE

Email: ohkay@khtdr.com

Relatively unchanged since 2010. .RE See https://github.com/khtdr/opts/blob/master/CHANGES.org

BSD 2-Clause License .RE See https://github.com/khtdr/opts/blob/master/LICENSE.txt