commander 2.7.1

the complete solution for node.js command-line programs


Platform: npm

Language: JavaScript

License: MIT

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Install: npm install commander


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The complete solution for node.js command-line interfaces, inspired by Ruby's commander.
API documentation


$ npm install commander

Option parsing

Options with commander are defined with the .option() method, also serving as documentation for the options. The example below parses args and options from process.argv, leaving remaining args as the program.args array which were not consumed by options.

#!/usr/bin/env node
 * Module dependencies.
var program = require('commander');
 .option('-p, --peppers', 'Add peppers')
 .option('-P, --pineapple', 'Add pineapple')
 .option('-b, --bbq-sauce', 'Add bbq sauce')
 .option('-c, --cheese [type]', 'Add the specified type of cheese [marble]', 'marble')
console.log('you ordered a pizza with:');
if (program.peppers) console.log(' - peppers');
if (program.pineapple) console.log(' - pineapple');
if (program.bbqSauce) console.log(' - bbq');
console.log(' - %s cheese', program.cheese);

Short flags may be passed as a single arg, for example -abc is equivalent to -a -b -c. Multi-word options such as "--template-engine" are camel-cased, becoming program.templateEngine etc.


function range(val) {
 return val.split('..').map(Number);
function list(val) {
 return val.split(',');
function collect(val, memo) {
 return memo;
function increaseVerbosity(v, total) {
 return total + 1;
 .usage('[options] <file ...>')
 .option('-i, --integer <n>', 'An integer argument', parseInt)
 .option('-f, --float <n>', 'A float argument', parseFloat)
 .option('-r, --range <a>..<b>', 'A range', range)
 .option('-l, --list <items>', 'A list', list)
 .option('-o, --optional [value]', 'An optional value')
 .option('-c, --collect [value]', 'A repeatable value', collect, [])
 .option('-v, --verbose', 'A value that can be increased', increaseVerbosity, 0)
console.log(' int: %j', program.integer);
console.log(' float: %j', program.float);
console.log(' optional: %j', program.optional);
program.range = program.range || [];
console.log(' range: %j..%j', program.range[0], program.range[1]);
console.log(' list: %j', program.list);
console.log(' collect: %j', program.collect);
console.log(' verbosity: %j', program.verbose);
console.log(' args: %j', program.args);

Regular Expression

 .option('-s --size <size>', 'Pizza size', /^(large|medium|small)$/i, 'medium')
 .option('-d --drink [drink]', 'Drink', /^(coke|pepsi|izze)$/i)
console.log(' size: %j', program.size);
console.log(' drink: %j', program.drink);

Variadic arguments

The last argument of a command can be variadic, and only the last argument. To make an argument variadic you have to append ... to the argument name. Here is an example:

#!/usr/bin/env node
 * Module dependencies.
var program = require('commander');
 .command('rmdir <dir> [otherDirs...]')
 .action(function (dir, otherDirs) {
 console.log('rmdir %s', dir);
 if (otherDirs) {
 otherDirs.forEach(function (oDir) {
 console.log('rmdir %s', oDir);

An Array is used for the value of a variadic argument. This applies to program.args as well as the argument passed to your action as demonstrated above.

Git-style sub-commands

// file: ./examples/pm
var program = require('..');
 .command('install [name]', 'install one or more packages')
 .command('search [query]', 'search with optional query')
 .command('list', 'list packages installed')

When .command() is invoked with a description argument, no .action(callback) should be called to handle sub-commands, otherwise there will be an error. This tells commander that you're going to use separate executables for sub-commands, much like git(1) and other popular tools.
The commander will try to search the executables in the directory of the entry script (like ./examples/pm) with the name program-command, like pm-install, pm-search.

If the program is designed to be installed globally, make sure the executables have proper modes, like 755.

Automated --help

The help information is auto-generated based on the information commander already knows about your program, so the following --help info is for free:

 $ ./examples/pizza --help
 Usage: pizza [options]
 An application for pizzas ordering
 -h, --help output usage information
 -V, --version output the version number
 -p, --peppers Add peppers
 -P, --pineapple Add pineapple
 -b, --bbq Add bbq sauce
 -c, --cheese <type> Add the specified type
 of cheese [marble]
 -C, --no-cheese You do not want any cheese

Custom help

You can display arbitrary -h, --help information by listening for "--help". Commander will automatically exit once you are done so that the remainder of your program does not execute causing undesired behaviours, for example in the following executable "stuff" will not output when --help is used.

#!/usr/bin/env node
 * Module dependencies.
var program = require('commander');
 .option('-f, --foo', 'enable some foo')
 .option('-b, --bar', 'enable some bar')
 .option('-B, --baz', 'enable some baz');
// must be before .parse() since
// node's emit() is immediate
program.on('--help', function(){
 console.log(' Examples:');
 console.log(' $ custom-help --help');
 console.log(' $ custom-help -h');

Yields the following help output when node script-name.js -h or node script-name.js --help are run:

Usage: custom-help [options]
 -h, --help output usage information
 -V, --version output the version number
 -f, --foo enable some foo
 -b, --bar enable some bar
 -B, --baz enable some baz
 $ custom-help --help
 $ custom-help -h


Output help information without exiting.

If you want to display help by default (e.g. if no command was provided), you can use something like:

var program = require('commander');
 .command('getstream [url]', 'get stream URL')
 if (!process.argv.slice(2).length) {


Output help information and exit immediately.


var program = require('commander');
 .option('-C, --chdir <path>', 'change the working directory')
 .option('-c, --config <path>', 'set config path. defaults to ./deploy.conf')
 .option('-T, --no-tests', 'ignore test hook')
 .command('setup [env]')
 .description('run setup commands for all envs')
 .option("-s, --setup_mode [mode]", "Which setup mode to use")
 .action(function(env, options){
 var mode = options.setup_mode || "normal";
 env = env || 'all';
 console.log('setup for %s env(s) with %s mode', env, mode);
 .command('exec <cmd>')
 .description('execute the given remote cmd')
 .option("-e, --exec_mode <mode>", "Which exec mode to use")
 .action(function(cmd, options){
 console.log('exec "%s" using %s mode', cmd, options.exec_mode);
 }).on('--help', function() {
 console.log(' Examples:');
 console.log(' $ deploy exec sequential');
 console.log(' $ deploy exec async');
 console.log('deploying "%s"', env);

More Demos can be found in the examples directory.



веселые картинки развлекательные гифки интресные факты смешные видео смешные истории из соцсетей


Development Dependencies

GitHub Repository

tj/commander.js tj/commander.js

node.js command-line interfaces made easy

Language: JavaScript

Created: August 14, 2011 21:33

Last updated: March 27, 2015 02:32

Last pushed: March 26, 2015 23:17

Size: 2.04 MB

Stars: 3,490

Forks: 329

Watchers: 101

Open issues: 71

Top Contributors

TJ Holowaychuk Zhiye Li Randall Koutnik Thomas Geraghty Tony Lukasavage Itay Neeman Sébastien De Bollivier Mithgol Andrew Nichols Felix Geisendörfer Peter Lyons Quentin Buathier Alexej Yaroshevich palanik Markus Padourek Jerry Hamlet Jonathan Delgado David Huttleston Jr Way, No Simon Oulevay


  • 2.7.1 - March 11, 2015 00:46
  • 2.7.0 - March 09, 2015 15:28
  • 2.6.0 - December 29, 2014 16:16
  • 2.5.1 - December 15, 2014 12:57
  • 2.5.0 - October 24, 2014 07:41
  • 2.4.0 - October 17, 2014 14:16
  • 2.3.0 - July 16, 2014 02:14
  • 2.2.0 - March 29, 2014 12:36
  • 2.1.0 - November 21, 2013 17:06
  • 2.0.0 - July 19, 2013 00:55
See all 42 releases

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