Move Command in php

echo "Move Command";
$sourcepath="source folder";
$detionationpath="destinationfolder";

echo $cmd= "mv -R ".$sourcepath ." ".$detionationpath;
exec($cmd,$output,$cpresult);
if($cpresult==0)
{
echo "transferd
";
}
else
{
echo "Some transferproblem";
}
?>