# Commander.js
The complete solution for [node.js](http://nodejs.org) command-line interfaces, inspired by Ruby's [commander](https://github.com/visionmedia/commander).
[](http://travis-ci.org/visionmedia/commander.js)
## Installation
$ 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.
```js
#!/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(' - pineappe');
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.
## 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]
Options:
-V, --version output the version number
-p, --peppers Add peppers
-P, --pineapple Add pineappe
-b, --bbq Add bbq sauce
-c, --cheese <type> Add the specified type of cheese [marble]
-h, --help output usage information
```
## Coercion
```js
function range(val) {
return val.split('..').map(Number);
}
function list(val) {
return val.split(',');
}
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')
.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(' args: %j', program.args);
```
## 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.
```js
#!/usr/bin/env node
/**
* Module dependencies.
*/
var program = require('../');
function list(val) {
return val.split(',').map(Number);
}
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');
```
yielding the following help output:
```
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
```
## .prompt(msg, fn)
Single-line prompt:
```js
program.prompt('name: ', function(name){
console.log('hi %s', name);
});
```
Multi-line prompt:
```js
program.prompt('description:', function(name){
console.log('hi %s', name);
});
```
Coercion:
```js
program.prompt('Age: ', Number, function(age){
console.log('age: %j', age);
});
```
```js
program.prompt('Birthdate: ', Date, function(date){
console.log('date: %s', date);
});
```
## .password(msg[, mask], fn)
Prompt for password without echoing:
```js
program.password('Password: ', function(pass){
console.log('got "%s"', pass);
process.stdin.destroy();
});
```
Prompt for password with mask char "*":
```js
program.password('Password: ', '*', function(pass){
console.log('got "%s"', pass);
process.stdin.destroy();
});
```
## .confirm(msg, fn)
Confirm with the given `msg`:
```js
program.confirm('continue? ', function(ok){
console.log(' got %j', ok);
});
```
## .choose(list, fn)
Let the user choose from a `list`:
```js
var list = ['tobi', 'loki', 'jane', 'manny', 'luna'];
console.log('Choose the coolest pet:');
program.choose(list, function(i){
console.log('you chose %d "%s"', i, list[i]);
});
```
## Links
- [API documentation](http://visionmedia.github.com/commander.js/)
- [ascii tables](https://github.com/LearnBoost/cli-table)
- [progress bars](https://github.com/visionmedia/node-progress)
- [more progress bars](https://github.com/substack/node-multimeter)
- [examples](https://github.com/visionmedia/commander.js/tree/master/examples)
## License
(The MIT License)
Copyright (c) 2011 TJ Holowaychuk <tj@vision-media.ca>
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.
Submit an article or tip