How to find the user IP address that visiting the page using PHP?

Question

How to find visitor IP address of website using PHP to log each visit?

Answer 1

PHP $_SERVER	Description
$_SERVER['REMOTE_ADDR']	Most reliable way to get client IP address in PHP
$_SERVER'[HTTP_CLIENT_IP']	This when user is behind proxy
$_SERVER['HTTP_X_FORWARDED_FOR']	This when user is behind proxy
$_SERVER['HTTP_X_FORWARDED']	This when user is behind proxy
$_SERVER['HTTP_FORWARDED_FOR'	This when user is behind proxy
$_SERVER['HTTP_FORWARDED']	This when user is behind proxy
$_SERVER['HTTP_X_CLUSTER_CLIENT_IP']	This when user is behind proxy

 

<?php
echo GetClientIP(true);

function GetClientIP($validate = False){
  $ipkeys = array(
  'REMOTE_ADDR', 
  'HTTP_CLIENT_IP', 
  'HTTP_X_FORWARDED_FOR', 
  'HTTP_X_FORWARDED', 
  'HTTP_FORWARDED_FOR', 
  'HTTP_FORWARDED', 
  'HTTP_X_CLUSTER_CLIENT_IP'
  );
  
  /*
  now we check each key against $_SERVER if contain such value
  */
  $ip = array();
  foreach($ipkeys as $keyword){
    if( isset($_SERVER[$keyword]) ){
      if($validate){
        if( ValidatePublicIP($_SERVER[$keyword]) ){
          $ip[] = $_SERVER[$keyword];
        }
      }else{
        $ip[] = $_SERVER[$keyword];
      }
    }
  }
  
  $ip = ( empty($ip) ? 'Unknown' : implode(", ", $ip) );
  return $ip;
  
}
function ValidatePublicIP($ip){
  if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
    return true;
  }
  else {
    return false;
  }
}

?>