Optimist

Optimist is a node.js library for option parsing for people who hate option parsing. More specifically, this module is for people who like all the --bells and -whistlz of program usage but think optstrings are a waste of time.

But all hope is not lost, dear reader, because there is Optimist, proving that option parsing doesn't have to suck (as much).

With Optimist, the options are just a hash! No optstrings attached.

xup.js:

#!/usr/bin/env node
var argv = require('optimist').argv;

if (argv.rif - 5 * argv.xup > 7.138) {
    console.log('Buy more riffiwobbles');
}
else {
    console.log('Sell the xupptumblers');
}

---

$ ./xup.js --rif=55 --xup=9.52
Buy more riffiwobbles

But wait! There's more! You can do short options:

short.js:

#!/usr/bin/env node
var argv = require('optimist').argv;
console.log('(%d,%d)', argv.x, argv.y);

---

$ ./short.js -x 10 -y 21
(10,21)

And booleans, both long and short (and grouped):

bool.js:

#!/usr/bin/env node
var sys = require('sys');
var argv = require('optimist').argv;

if (argv.s) {
    sys.print(argv.fr ? 'Le chat dit: ' : 'The cat says: ');
}
console.log(
    (argv.fr ? 'miaou' : 'meow') + (argv.p ? '.' : '')
);

---

$ ./bool.js -s
The cat says: meow

$ ./bool.js -sp
The cat says: meow.

$ ./bool.js -sp --fr
Le chat dit: miaou.

And non-hypenated options too! Just use argv._!

nonopt.js:

#!/usr/bin/env node
var argv = require('optimist').argv;
console.log('(%d,%d)', argv.x, argv.y);
console.log(argv._);

---

$ ./nonopt.js -x 6.82 -y 3.35 moo
(6.82,3.35)
[ 'moo' ]

$ ./nonopt.js foo -x 0.54 bar -y 1.12 baz
(0.54,1.12)
[ 'foo', 'bar', 'baz' ]

Plus, Optimist comes with .usage() and .demand()!

divide.js: #!/usr/bin/env node var argv = require('optimist') .usage('Usage: $0 -x [num] -y [num]') .demand(['x','y']) .argv;

console.log(argv.x / argv.y);

---

$ ./divide.js -x 55 -y 11
5

$ ./divide.js -x 4.91 -z 2.51
Usage: ./divide.js -x [num] -y [num]
Missing arguments: y

Installation

With npm, just do: npm install optimist

or clone this project on github:

git clone http://github.com/substack/node-optimist.git

To run the tests with expresso, just do:

expresso

Inspired By

This module is loosely inspired by Perl's Getopt::Casual.