$location = "\\\\192.168.15.98\\digi";
$user     = "digi";
$password = "digi";
$letter   = "M";

echo $command = "net use ".$letter.": \"".$location."\" ".$password." /user:".$user." /persistent:no>nul 2>&1";
echo "<br />";
system($command);

$row = scandir($letter.':\\資料夾');

if($row !== false){

    foreach($row as $value){

        echo $value.'<br />';

    }

}