Wget avec exec() ( PHP )

$cmd = "/usr/bin/wget 'http://www.*****.com/****/Track 04.mp3' -O ".$url;

wget "http://www.*****.com/*****/test123.mp3" -O "/*****/*****/******/www/test1234.mp3"

<?php
if(isset($_POST['path']) && isset($_POST['url']))
{

$path = $_POST['path'];
$url = $_POST['url'];
$cmd = "wget \"$url\" -O \"$path\"";
exec ($cmd);
echo" La commande a bien été exécutée : $cmd ";
}
print "<form action=\"$PHP_SELF\" method=post>
Lien (URL)  : <input name=url><br>
Path Complet: <input name=path><br>
<input type=submit value=\"envoyer\">";

?>