get_ip

<?php
function get_ip($def=false){
        global $REMOTE_ADDR;
        global $HTTP_X_FORWARDED_FOR, $HTTP_X_FORWARDED, $HTTP_FORWARDED_FOR, $HTTP_FORWARDED;
        global $HTTP_VIA, $HTTP_X_COMING_FROM, $HTTP_COMING_FROM;
        global $HTTP_SERVER_VARS, $HTTP_ENV_VARS;
        if(empty($REMOTE_ADDR)){
            if(!empty($_SERVER)&&isset($_SERVER['REMOTE_ADDR'])){
                $REMOTE_ADDR = $_SERVER['REMOTE_ADDR'];
            }elseif(!empty($_ENV)&&isset($_ENV['REMOTE_ADDR'])){
                $REMOTE_ADDR = $_ENV['REMOTE_ADDR'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['REMOTE_ADDR'])){
                $REMOTE_ADDR = $HTTP_SERVER_VARS['REMOTE_ADDR'];
            }elseif(!empty($HTTP_ENV_VARS)&&isset($HTTP_ENV_VARS['REMOTE_ADDR'])){
                $REMOTE_ADDR = $HTTP_ENV_VARS['REMOTE_ADDR'];
            }elseif(@getenv('REMOTE_ADDR')){
                $REMOTE_ADDR = getenv('REMOTE_ADDR');
            }
        }
        if(empty($HTTP_X_FORWARDED_FOR)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_X_FORWARDED_FOR'])){
                $HTTP_X_FORWARDED_FOR = $_SERVER['HTTP_X_FORWARDED_FOR'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_X_FORWARDED_FOR'])){
                $HTTP_X_FORWARDED_FOR = $_ENV['HTTP_X_FORWARDED_FOR'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['HTTP_X_FORWARDED_FOR'])){
                $HTTP_X_FORWARDED_FOR = $HTTP_SERVER_VARS['HTTP_X_FORWARDED_FOR'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_X_FORWARDED_FOR'])){
                $HTTP_X_FORWARDED_FOR = $HTTP_ENV_VARS['HTTP_X_FORWARDED_FOR'];
            }elseif(@getenv('HTTP_X_FORWARDED_FOR')){
                $HTTP_X_FORWARDED_FOR = getenv('HTTP_X_FORWARDED_FOR');
            }
        }
        if(empty($HTTP_X_FORWARDED)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_X_FORWARDED'])){
                $HTTP_X_FORWARDED = $_SERVER['HTTP_X_FORWARDED'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_X_FORWARDED'])){
                $HTTP_X_FORWARDED = $_ENV['HTTP_X_FORWARDED'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['HTTP_X_FORWARDED'])){
                $HTTP_X_FORWARDED = $HTTP_SERVER_VARS['HTTP_X_FORWARDED'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_X_FORWARDED'])){
                $HTTP_X_FORWARDED = $HTTP_ENV_VARS['HTTP_X_FORWARDED'];
            }elseif(@getenv('HTTP_X_FORWARDED')){
                $HTTP_X_FORWARDED = getenv('HTTP_X_FORWARDED');
            }
        }
        if(empty($HTTP_FORWARDED_FOR)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_FORWARDED_FOR'])){
                $HTTP_FORWARDED_FOR = $_SERVER['HTTP_FORWARDED_FOR'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_FORWARDED_FOR'])){
                $HTTP_FORWARDED_FOR = $_ENV['HTTP_FORWARDED_FOR'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['HTTP_FORWARDED_FOR'])){
                $HTTP_FORWARDED_FOR = $HTTP_SERVER_VARS['HTTP_FORWARDED_FOR'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_FORWARDED_FOR'])){
                $HTTP_FORWARDED_FOR = $HTTP_ENV_VARS['HTTP_FORWARDED_FOR'];
            }elseif(@getenv('HTTP_FORWARDED_FOR')){
                $HTTP_FORWARDED_FOR = getenv('HTTP_FORWARDED_FOR');
            }
        }
        if(empty($HTTP_FORWARDED)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_FORWARDED'])){
                $HTTP_FORWARDED = $_SERVER['HTTP_FORWARDED'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_FORWARDED'])){
                $HTTP_FORWARDED = $_ENV['HTTP_FORWARDED'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['HTTP_FORWARDED'])){
                $HTTP_FORWARDED = $HTTP_SERVER_VARS['HTTP_FORWARDED'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_FORWARDED'])){
                $HTTP_FORWARDED = $HTTP_ENV_VARS['HTTP_FORWARDED'];
            }elseif(@getenv('HTTP_FORWARDED')){
                $HTTP_FORWARDED = getenv('HTTP_FORWARDED');
            }
        }
        if(empty($HTTP_VIA)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_VIA'])){
                $HTTP_VIA = $_SERVER['HTTP_VIA'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_VIA'])){
                $HTTP_VIA = $_ENV['HTTP_VIA'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['HTTP_VIA'])){
                $HTTP_VIA = $HTTP_SERVER_VARS['HTTP_VIA'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_VIA'])){
                $HTTP_VIA = $HTTP_ENV_VARS['HTTP_VIA'];
            }elseif(@getenv('HTTP_VIA')){
                $HTTP_VIA = getenv('HTTP_VIA');
            }
        }

        if(empty($HTTP_X_COMING_FROM)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_X_COMING_FROM'])){
                $HTTP_X_COMING_FROM = $_SERVER['HTTP_X_COMING_FROM'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_X_COMING_FROM'])){
                $HTTP_X_COMING_FROM = $_ENV['HTTP_X_COMING_FROM'];
            }elseif(!empty($HTTP_SERVER_VARS) && isset($HTTP_SERVER_VARS['HTTP_X_COMING_FROM'])){
                $HTTP_X_COMING_FROM = $HTTP_SERVER_VARS['HTTP_X_COMING_FROM'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_X_COMING_FROM'])){
                $HTTP_X_COMING_FROM = $HTTP_ENV_VARS['HTTP_X_COMING_FROM'];
            }elseif(@getenv('HTTP_X_COMING_FROM')){
                $HTTP_X_COMING_FROM = getenv('HTTP_X_COMING_FROM');
            }
        }

        if(empty($HTTP_COMING_FROM)){
            if(!empty($_SERVER) && isset($_SERVER['HTTP_COMING_FROM'])){
                $HTTP_COMING_FROM = $_SERVER['HTTP_COMING_FROM'];
            }elseif(!empty($_ENV) && isset($_ENV['HTTP_COMING_FROM'])){
                $HTTP_COMING_FROM = $_ENV['HTTP_COMING_FROM'];
            }elseif(!empty($HTTP_COMING_FROM) && isset($HTTP_SERVER_VARS['HTTP_COMING_FROM'])){
                $HTTP_COMING_FROM = $HTTP_SERVER_VARS['HTTP_COMING_FROM'];
            }elseif(!empty($HTTP_ENV_VARS) && isset($HTTP_ENV_VARS['HTTP_COMING_FROM'])){
                $HTTP_COMING_FROM = $HTTP_ENV_VARS['HTTP_COMING_FROM'];
            }elseif(@getenv('HTTP_COMING_FROM')){
                $HTTP_COMING_FROM = getenv('HTTP_COMING_FROM');
            }
        }

        if(!empty($REMOTE_ADDR)){
            $direct_ip = $REMOTE_ADDR;
        }

        $proxy_ip='';
        if(!empty($HTTP_X_FORWARDED_FOR))$proxy_ip = $HTTP_X_FORWARDED_FOR;
        elseif(!empty($HTTP_X_FORWARDED))$proxy_ip = $HTTP_X_FORWARDED;
        elseif(!empty($HTTP_FORWARDED_FOR))$proxy_ip = $HTTP_FORWARDED_FOR;
        elseif(!empty($HTTP_FORWARDED))$proxy_ip = $HTTP_FORWARDED;
        elseif(!empty($HTTP_VIA))$proxy_ip = $HTTP_VIA;
        elseif(!empty($HTTP_X_COMING_FROM))$proxy_ip = $HTTP_X_COMING_FROM;
        elseif(!empty($HTTP_COMING_FROM))$proxy_ip = $HTTP_COMING_FROM;
        if(empty($proxy_ip)){
            return $direct_ip;
        }else{
            $is_ip = preg_match('/^([0-9]{1,3}\.){3,3}[0-9]{1,3}/i', $proxy_ip, $regs);
            if($is_ip && (count($regs) > 0)){
                return $regs[0];
            }else{
                return $def;
            }
        }
    }