The complete solution for node.js command-line interfaces, inspired by Ruby's commander.
API documentation
$ npm install commander
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');
program
.version('0.0.1')
.option('-p, --peppers', 'Add peppers')
.option('-P, --pineapple', 'Add pineapple')
.option('-b, --bbq', 'Add bbq sauce')
.option('-c, --cheese [type]', 'Add the specified type of cheese [marble]', 'marble')
.parse(process.argv);
console.log('you ordered a pizza with:');
if (program.peppers) console.log(' - peppers');
if (program.pineapple) console.log(' - pineapple');
if (program.bbq) 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) {
memo.push(val);
return memo;
}
function increaseVerbosity(v, total) {
return total + 1;
}
program
.version('0.0.1')
.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)
.parse(process.argv);
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);
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');
program
.version('0.0.1')
.command('rmdir <dir> [otherDirs...]')
.action(function (dir, otherDirs) {
console.log('rmdir %s', dir);
if (otherDirs) {
otherDirs.forEach(function (oDir) {
console.log('rmdir %s', oDir);
});
}
});
program.parse(process.argv);
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.
// file: ./examples/pm
var program = require('..');
program
.version('0.0.1')
.command('install [name]', 'install one or more packages')
.command('search [query]', 'search with optional query')
.command('list', 'list packages installed')
.parse(process.argv);
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 find the executable script in current directory with the name scriptBasename-subcommand
, like pm-install
, pm-search
.
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
Options:
-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
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');
program
.version('0.0.1')
.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('');
console.log(' $ custom-help --help');
console.log(' $ custom-help -h');
console.log('');
});
program.parse(process.argv);
console.log('stuff');
Yields the following help output when node script-name.js -h
or node script-name.js --help
are run:
Usage: custom-help [options]
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
Examples:
$ 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');
program
.version('0.0.1')
.command('getstream [url]', 'get stream URL')
.parse(process.argv);
if (!process.argv.slice(2).length) {
program.outputHelp();
}
Output help information and exit immediately.
var program = require('commander');
program
.version('0.0.1')
.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')
program
.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);
});
program
.command('exec <cmd>')
.alias('ex')
.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();
console.log(' $ deploy exec sequential');
console.log(' $ deploy exec async');
console.log();
});
program
.command('*')
.action(function(env){
console.log('deploying "%s"', env);
});
program.parse(process.argv);
You can see more Demos in the examples directory.
(The MIT License)
Copyright (c) 2011 TJ Holowaychuk <[email protected]>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.