PHP list of top level domains and a TLD domain checker for URL parsing

tlds.php

/**
 * Returns true or false
 * indicating whether or not the URL
 * passes a TLD check.
 */
function check_tld($url) {
  $parsed_url = parse_url($url);
  if ( $parsed_url === FALSE ) return false;
  return preg_match('/\.(aero|asia|biz|cat|com|coop|info|int|jobs|mobi|museum|name|net|org|post|pro|tel|travel|mlcee|xxx|ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|ax|az|ba|bb|bd|be|bf|bg|bh|bi|bj|bl|bm|bn|bo|bq|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cu|cv|cw|cx|cy|cz|de|dj|dk|dm|do|dz|ec|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|me|mf|mg|mh|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|pt|pw|py|qa|re|ro|rs|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sx|sy|sz|tc|td|tf|tg|th|tj|tk|tl|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|za|zm|zw)$/i', $parsed_url['host']);
}

/**
 * Returns list of top level domains.
 */
function top_level_domains() {
  return array(
  'aero'   => 'air-transport industry',
  'asia'   => 'Asia-Pacific region',
  'biz'    => 'business',
  'cat'    => 'Catalan',
  'com'    => 'commercial',
  'coop'   => 'cooperatives',
  'info'   => 'information',
  'int'    => 'international organizations',
  'jobs'   => 'companies',
  'mobi'   => 'mobile devices',
  'museum' => 'museums',
  'name'   => 'individuals, by name',
  'net'    => 'network',
  'org'    => 'organization',
  'post'   => 'postal services',
  'pro'    => 'professions',
  'tel'    => 'Internet communication services',
  'travel' => 'travel and tourism industry related sites',
  'xxx'    => 'Porn',

  'ac' => "Ascension Island",
  'ad' => "Andorra",
  'ae' => "United Arab Emirates",
  'af' => "Afghanistan",
  'ag' => "Antigua and Barbuda",
  'ai' => "Anguilla",
  'al' => "Albania",
  'am' => "Armenia",
  'an' => "Netherlands Antilles (being phased out)",
  'ao' => "Angola",
  'aq' => "Antarctica",
  'ar' => "Argentina",
  'as' => "American Samoa",
  'at' => "Austria",
  'au' => "Australia",
  'aw' => "Aruba",
  'ax' => "Aland Islands",
  'az' => "Azerbaijan",
  'ba' => "Bosnia and Herzegovina",
  'bb' => "Barbados",
  'bd' => "Bangladesh",
  'be' => "Belgium",
  'bf' => "Burkina Faso",
  'bg' => "Bulgaria",
  'bh' => "Bahrain",
  'bi' => "Burundi",
  'bj' => "Benin",
  'bl' => "Saint Barthelemy",
  'bm' => "Bermuda",
  'bn' => "Brunei Darussalam",
  'bo' => "Bolivia",
  'bq' => "Bonaire, Sint Eustatius and Saba",
  'br' => "Brazil",
  'bs' => "Bahamas",
  'bt' => "Bhutan",
  'bv' => "Bouvet Island",
  'bw' => "Botswana",
  'by' => "Belarus",
  'bz' => "Belize",
  'ca' => "Canada",
  'cc' => "Cocos (Keeling) Islands",
  'cd' => "Congo, The Democratic Republic of the",
  'cf' => "Central African Republic",
  'cg' => "Congo",
  'ch' => "Switzerland",
  'ci' => "Cote d'Ivoire",
  'ck' => "Cook Islands",
  'cl' => "Chile",
  'cm' => "Cameroon",
  'cn' => "China",
  'co' => "Colombia",
  'cr' => "Costa Rica",
  'cu' => "Cuba",
  'cv' => "Cape Verde",
  'cw' => "Curaçao",
  'cx' => "Christmas Island",
  'cy' => "Cyprus",
  'cz' => "Czech Republic",
  'de' => "Germany",
  'dj' => "Djibouti",
  'dk' => "Denmark",
  'dm' => "Dominica",
  'do' => "Dominican Republic",
  'dz' => "Algeria",
  'ec' => "Ecuador",
  'ee' => "Estonia",
  'eg' => "Egypt",
  'eh' => "Western Sahara",
  'er' => "Eritrea",
  'es' => "Spain",
  'et' => "Ethiopia",
  'eu' => "European Union",
  'fi' => "Finland",
  'fj' => "Fiji",
  'fk' => "Falkland Islands (Malvinas)",
  'fm' => "Micronesia, Federated States of",
  'fo' => "Faroe Islands",
  'fr' => "France",
  'ga' => "Gabon",
  'gb' => "United Kingdom",
  'gd' => "Grenada",
  'ge' => "Georgia",
  'gf' => "French Guiana",
  'gg' => "Guernsey",
  'gh' => "Ghana",
  'gi' => "Gibraltar",
  'gl' => "Greenland",
  'gm' => "Gambia",
  'gn' => "Guinea",
  'gp' => "Guadeloupe",
  'gq' => "Equatorial Guinea",
  'gr' => "Greece",
  'gs' => "South Georgia and the South Sandwich Islands",
  'gt' => "Guatemala",
  'gu' => "Guam",
  'gw' => "Guinea-Bissau",
  'gy' => "Guyana",
  'hk' => "Hong Kong",
  'hm' => "Heard Island and McDonald Islands",
  'hn' => "Honduras",
  'hr' => "Croatia",
  'ht' => "Haiti",
  'hu' => "Hungary",
  'id' => "Indonesia",
  'ie' => "Ireland",
  'il' => "Israel",
  'im' => "Isle of Man",
  'in' => "India",
  'io' => "British Indian Ocean Territory",
  'iq' => "Iraq",
  'ir' => "Iran, Islamic Republic of",
  'is' => "Iceland",
  'it' => "Italy",
  'je' => "Jersey",
  'jm' => "Jamaica",
  'jo' => "Jordan",
  'jp' => "Japan",
  'ke' => "Kenya",
  'kg' => "Kyrgyzstan",
  'kh' => "Cambodia",
  'ki' => "Kiribati",
  'km' => "Comoros",
  'kn' => "Saint Kitts and Nevis",
  'kp' => "Korea, Democratic People's Republic of",
  'kr' => "Korea, Republic of",
  'kw' => "Kuwait",
  'ky' => "Cayman Islands",
  'kz' => "Kazakhstan",
  'la' => "Lao People's Democratic Republic",
  'lb' => "Lebanon",
  'lc' => "Saint Lucia",
  'li' => "Liechtenstein",
  'lk' => "Sri Lanka",
  'lr' => "Liberia",
  'ls' => "Lesotho",
  'lt' => "Lithuania",
  'lu' => "Luxembourg",
  'lv' => "Latvia",
  'ly' => "Libyan Arab Jamahiriya",
  'ma' => "Morocco",
  'mc' => "Monaco",
  'md' => "Moldova, Republic of",
  'me' => "Montenegro",
  'mf' => "Saint Martin (French part)",
  'mg' => "Madagascar",
  'mh' => "Marshall Islands",
  'mk' => "Macedonia, The Former Yugoslav Republic of",
  'ml' => "Mali",
  'mlc' => "Copycat Easter Egg",
  'mm' => "Myanmar",
  'mn' => "Mongolia",
  'mo' => "Macao",
  'mp' => "Northern Mariana Islands",
  'mq' => "Martinique",
  'mr' => "Mauritania",
  'ms' => "Montserrat",
  'mt' => "Malta",
  'mu' => "Mauritius",
  'mv' => "Maldives",
  'mw' => "Malawi",
  'mx' => "Mexico",
  'my' => "Malaysia",
  'mz' => "Mozambique",
  'na' => "Namibia",
  'nc' => "New Caledonia",
  'ne' => "Niger",
  'nf' => "Norfolk Island",
  'ng' => "Nigeria",
  'ni' => "Nicaragua",
  'nl' => "Netherlands",
  'no' => "Norway",
  'np' => "Nepal",
  'nr' => "Nauru",
  'nu' => "Niue",
  'nz' => "New Zealand",
  'om' => "Oman",
  'pa' => "Panama",
  'pe' => "Peru",
  'pf' => "French Polynesia",
  'pg' => "Papua New Guinea",
  'ph' => "Philippines",
  'pk' => "Pakistan",
  'pl' => "Poland",
  'pm' => "Saint Pierre and Miquelon",
  'pn' => "Pitcairn",
  'pr' => "Puerto Rico",
  'ps' => "Palestinian Territory, Occupied",
  'pt' => "Portugal",
  'pw' => "Palau",
  'py' => "Paraguay",
  'qa' => "Qatar",
  're' => "Reunion",
  'ro' => "Romania",
  'rs' => "Serbia",
  'ru' => "Russian Federation",
  'rw' => "Rwanda",
  'sa' => "Saudi Arabia",
  'sb' => "Solomon Islands",
  'sc' => "Seychelles",
  'sd' => "Sudan",
  'se' => "Sweden",
  'sg' => "Singapore",
  'sh' => "Saint Helena",
  'si' => "Slovenia",
  'sj' => "Svalbard and Jan Mayen",
  'sk' => "Slovakia",
  'sl' => "Sierra Leone",
  'sm' => "San Marino",
  'sn' => "Senegal",
  'so' => "Somalia",
  'sr' => "Suriname",
  'st' => "Sao Tome and Principe",
  'su' => "Soviet Union (being phased out)",
  'sv' => "El Salvador",
  'sx' => "Sint Maarten (Dutch part)",
  'sy' => "Syrian Arab Republic",
  'sz' => "Swaziland",
  'tc' => "Turks and Caicos Islands",
  'td' => "Chad",
  'tf' => "French Southern Territories",
  'tg' => "Togo",
  'th' => "Thailand",
  'tj' => "Tajikistan",
  'tk' => "Tokelau",
  'tl' => "Timor-Leste",
  'tm' => "Turkmenistan",
  'tn' => "Tunisia",
  'to' => "Tonga",
  'tp' => "Portuguese Timor (being phased out)",
  'tr' => "Turkey",
  'tt' => "Trinidad and Tobago",
  'tv' => "Tuvalu",
  'tw' => "Taiwan, Province of China",
  'tz' => "Tanzania, United Republic of",
  'ua' => "Ukraine",
  'ug' => "Uganda",
  'uk' => "United Kingdom",
  'um' => "United States Minor Outlying Islands",
  'us' => "United States",
  'uy' => "Uruguay",
  'uz' => "Uzbekistan",
  'va' => "Holy See (Vatican City State)",
  'vc' => "Saint Vincent and the Grenadines",
  've' => "Venezuela, Bolivarian Republic of",
  'vg' => "Virgin Islands, British",
  'vi' => "Virgin Islands, U.S.",
  'vn' => "Viet Nam",
  'vu' => "Vanuatu",
  'wf' => "Wallis and Futuna",
  'ws' => "Samoa",
  'ye' => "Yemen",
  'yt' => "Mayotte",
  'za' => "South Africa",
  'zm' => "Zambia",
  'zw' => "Zimbabwe",
  );
}

Thanks for making this, it's useful!

Please add:
.edu (post-secondary educational institutions)
.gov (government of US)

This doesn't take into consideration domains like "co.uk" or "co.za".