Table of Contents

1. NAME
2. SYNOPSIS
1. running:
2. produces:
3. running:
4. produces:
5. running:
6. produces:
3. INSTALLATION
1. Stand-alone version
2. NPM version
4. USAGE
1. LOADING
2. CONFIGURING
1. options
2. arguments
3. help text generator
5. AUTHOR / CHANGELOG / LICENSE

Find the full documentation, source code, and examples online at .

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

$3

$ node ./example1

$3

Example 1

$3

$ node ./example1 --help

$3

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

$3

node ./example1 -v

$3

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

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

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

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.

$3

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
];

$3

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) { ... },
};

$3

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

BSD 2-Clause License
.RE
See