Uglify a javascript file.

build.js

#!/usr/local/bin/node

var fs = require('fs'),
  uglify = require('uglify-js'),
  header = function (name) {
    return '/*\n * ' + name + '.js ~ Copyright (c) 2012 My Copyright\n */\n';
  };

function buildFile() {
  var args = Array.prototype.slice.call(arguments);
  if (!args.length) return;

  var js = ''
    , name = '';
  for (var i = 0; i < args.length; i++) {
    try {
      console.log('minifying ' + args[i] + '.js');
      js += ' ' + fs.readFileSync(__dirname + '/' + args[i] + '.js').toString();
      name += ' ' + args[i] + '.js';
    } catch (err) {
      console.log(err);
      return;
    }
  }

  var ast = uglify.parser.parse(js);
  ast = uglify.uglify.ast_mangle(ast);
  ast = uglify.uglify.ast_squeeze(ast);
  var minifiedJS = uglify.uglify.gen_code(ast);
  console.log('writing to ' + args[0] + '.js');
  fs.writeFile(__dirname + '/' + args[0] + '.min.js', header(name) + minifiedJS);
}

console.log('building and minifying ...');
// make minified file from single js file
buildFile('filename_minus_js_extension');
// or combine files
buildFile('filename_minus_js_extension', 'another_file');
console.log('done');