exec('rm -r rpertoire');

Here's a short function I wrote to remove a directory and all it's contents using the glob() function:

function rmdirr($dir) {
   if($objs = glob($dir."/*")){
       foreach($objs as $obj) {
           is_dir($obj)? rmdirr($obj) : unlink($obj);
       }
   }
   rmdir($dir);
}

if (is_dir($path)){
$dir = opendir($path);
while ($f = readdir($dir)) {
   if(is_file($path.$f)) {
   unlink ($path.$f);
   }
else {}
   }
closedir($dir);
rmdir($path);
}