$ npm install commander

#!/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);

 $ ./examples/pizza --help

   Usage: pizza [options]

   Options:

     -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]
     -h, --help           output usage information

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);

#!/usr/bin/env node

/**
 * Module dependencies.
 */

var program = require('/');

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');

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