php检查字符串中是否有外链的方法_php技巧

/** * is_external_link 检测字符串是否包含外链 * @param string $text 文字 * @param string $host 域名 * @return boolean    false 有外链 true 无外链 * /function all_external_link($text = '', $host = '') {  if (empty($host)) $host = $_SERVER['HTTP_HOST'];  $reg = '/http(?:s?):\/\/((?:[A-za-z0-9-]+\.)+[A-za-z]{2,4})/';  preg_match_all($reg, $text, $data);  $math = $data[1];  foreach ($math as $value) {    if($value != $host) return false;  }  return true;}