function parse_url (str, component) {
  // http://kevin.vanzonneveld.net
  // +      original by: Steven Levithan (http://blog.stevenlevithan.com)
  // + reimplemented by: Brett Zamir (http://brett-zamir.me)
  // + input by: Lorenzo Pisani
  // + input by: Tony
  // + improved by: Brett Zamir (http://brett-zamir.me)
  // %          note: Based on http://stevenlevithan.com/demo/parseuri/js/assets/parseuri.js
  // %          note: blog post at http://blog.stevenlevithan.com/archives/parseuri
  // %          note: demo at http://stevenlevithan.com/demo/parseuri/js/assets/parseuri.js
  // %          note: Does not replace invalid characters with '_' as in PHP, nor does it return false with
  // %          note: a seriously malformed URL.
  // %          note: Besides function name, is essentially the same as parseUri as well as our allowing
  // %          note: an extra slash after the scheme/protocol (to allow file:/// as in PHP)
  // *     example 1: parse_url('http://username:password@hostname/path?arg=value#anchor');
  // *     returns 1: {scheme: 'http', host: 'hostname', user: 'username', pass: 'password', path: '/path', query: 'arg=value', fragment: 'anchor'}
  var query, key = ['source', 'scheme', 'authority', 'userInfo', 'user', 'pass', 'host', 'port',
            'relative', 'path', 'directory', 'file', 'query', 'fragment'],
    ini = (this.php_js && this.php_js.ini) || {},
    mode = (ini['phpjs.parse_url.mode'] &&
      ini['phpjs.parse_url.mode'].local_value) || 'php',
    parser = {
      php: /^(?:([^:\/?#]+):)?(?:\/\/()(?:(?:()(?:([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?()(?:(()(?:(?:[^?#\/]*\/)*)()(?:[^?#]*))(?:\?([^#]*))?(?:#(.*))?)/,
      strict: /^(?:([^:\/?#]+):)?(?:\/\/((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?((((?:[^?#\/]*\/)*)([^?#]*))(?:\?([^#]*))?(?:#(.*))?)/,
      loose: /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/\/?)?((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/ // Added one optional slash to post-scheme to catch file:/// (should restrict this)
    };

  var m = parser[mode].exec(str),
    uri = {},
    i = 14;
  while (i--) {
    if (m[i]) {
      uri[key[i]] = m[i];
    }
  }

  if (component) {
    return uri[component.replace('PHP_URL_', '').toLowerCase()];
  }
  if (mode !== 'php') {
    var name = (ini['phpjs.parse_url.queryKey'] &&
        ini['phpjs.parse_url.queryKey'].local_value) || 'queryKey';
    parser = /(?:^|&)([^&=]*)=?([^&]*)/g;
    uri[name] = {};
    query = uri[key[12]] || '';
    query.replace(parser, function ($0, $1, $2) {
      if ($1) {uri[name][$1] = $2;}
    });
  }
  delete uri.source;
  return uri;
}

parse_url('http://username:password@hostname/path?arg=value#anchor');

{scheme: 'http', host: 'hostname', user: 'username', pass: 'password', path: '/path', query: 'arg=value', fragment: 'anchor'}