flag In the variable ! <?php  

error_reporting
(0);
include 
"flag1.php";
highlight_file(__file__);
if(isset(
$_GET['args'])){
    
$args $_GET['args'];
    if(!
preg_match("/^\w+$/",$args)){
        die(
"args error!");
    }
    eval(
"var_dump($$args);");
}
?>