function get_meta_tags (file) {
  // Extracts all meta tag content attributes from a file and returns an array
  //
  // version: 905.3122
  // discuss at: http://phpjs.org/functions/get_meta_tags
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // %        note 1: This function uses XmlHttpRequest and cannot retrieve resource from different domain.
  // %        note 1: Synchronous so may lock up browser, mainly here for study purposes.
  // -    depends on: file_get_contents
  // *     example 1: get_meta_tags('http://kevin.vanzonneveld.net/pj_test_supportfile_2.htm');
  // *     returns 1: {description: 'a php manual', author: 'name', keywords: 'php documentation', 'geo_position': '49.33;-86.59'}
  var fulltxt = '';

  if (false) {
    // Use this for testing instead of the line above:
    fulltxt = '<meta name="author" content="name">' + '<meta name="keywords" content="php documentation">' + '<meta name="DESCRIPTION" content="a php manual">' + '<meta name="geo.position" content="49.33;-86.59">' + '</head>';
  } else {
    fulltxt = this.file_get_contents(file).match(/^[\s\S]*<\/head>/i); // We have to disallow some character, so we choose a Unicode non-character
  }

  var patt = /<meta[^>]*?>/gim;
  var patt1 = /<meta\s+.*?name\s*=\s*(['"]?)(.*?)\1\s+.*?content\s*=\s*(['"]?)(.*?)\3/gim;
  var patt2 = /<meta\s+.*?content\s*=\s*(['"?])(.*?)\1\s+.*?name\s*=\s*(['"]?)(.*?)\3/gim;
  var txt, match, name, arr = {};

  while ((txt = patt.exec(fulltxt)) !== null) {
    while ((match = patt1.exec(txt)) !== null) {
      name = match[2].replace(/\W/g, '_').toLowerCase();
      arr[name] = match[4];
    }
    while ((match = patt2.exec(txt)) !== null) {
      name = match[4].replace(/\W/g, '_').toLowerCase();
      arr[name] = match[2];
    }
  }
  return arr;
}

get_meta_tags('http://kevin.vanzonneveld.net/pj_test_supportfile_2.htm');

{description: 'a php manual', author: 'name', keywords: 'php documentation', 'geo_position': '49.33;-86.59'}