php检查验证IP为有效IP地址函数_PHP教程

 
if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE)) {// it's valid
}else {// it's not valid
}

if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {// it's valid
}else {// it's not valid
}

//判断IP格式
 function is_ip($gonten){
        $ip = explode(".",$gonten);
        for($i=0;$i        {
              if($ip[$i]>255){
               return (0);
               }
        }
        return ereg("^[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}$",$gonten);
}