PHP 获取客户端 IP 地址的方法实例代码

/** * 获取客户端IP地址 */function real_ip(){  $ip = $_SERVER['REMOTE_ADDR'];  if (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && preg_match_all('#/d{1,3}/./d{1,3}/./d{1,3}/./d{1,3}#s', $_SERVER['HTTP_X_FORWARDED_FOR'], $matches)) {    foreach ($matches[0] AS $xip) {      if (!preg_match('#^(10|172/.16|192/.168)/.#', $xip)) {        $ip = $xip;        break;      }    }  } elseif (isset($_SERVER['HTTP_CLIENT_IP']) && preg_match('/^([0-9]{1,3}/.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CLIENT_IP'])) {    $ip = $_SERVER['HTTP_CLIENT_IP'];  } elseif (isset($_SERVER['HTTP_CF_CONNECTING_IP']) && preg_match('/^([0-9]{1,3}/.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CF_CONNECTING_IP'])) {    $ip = $_SERVER['HTTP_CF_CONNECTING_IP'];  } elseif (isset($_SERVER['HTTP_X_REAL_IP']) && preg_match('/^([0-9]{1,3}/.){3}[0-9]{1,3}$/', $_SERVER['HTTP_X_REAL_IP'])) {    $ip = $_SERVER['HTTP_X_REAL_IP'];  }  return $ip;}