PHP Method instance code for getting client IP address

Let's first understand the meaning of one variable:

$_SERVER ['REMOTE_ADDR']: The ip address of the user's computer browsing the current page

$_SERVER ['HTTP_CLIENT_IP']: ip for the client

$_SERVER ['HTTP_X_FORWARDED_FOR']: The gateway of the user's computer browsing the current page

$_SERVER ['HTTP_X_REAL_IP']: In nginx proxy mode, get the real IP of the client

/**
 *  Get client IP Address 
 */
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;
}

Summarize

The above is the site to introduce you PHP access to the client IP address method example code, I hope to help you, if you have any questions welcome to leave me a message, this site will reply to you in time!