php function to get folder size

 // Get the folder size
 function getDirSize($dir)
 {
 $handle = opendir($dir);
 while (false!==($FolderOrFile = readdir($handle )))
 {
 if($FolderOrFile != "." && $FolderOrFile != "..")
 {
 if(is_dir("$dir/$FolderOrFile"))
 {
 $sizeResult += getDirSize( "$dir/$FolderOrFile");
 }
 else
 { bbs.it-home.org
 $sizeResult += filesize("$dir/$FolderOrFile");
 }
 }
 }
 closedir($handle) ;
 return $sizeResult;
 }
 // Automatic unit conversion function
 function getRealSize($size)
 {
 $kb = 1024; // Kilobyte
 $mb = 1024 * $kb; // Megabyte
 $gb = 1024 * $mb; // Gigabyte
 $tb = 1024 * $gb; // Terabyte

 if($size < $kb)
 {
 return $size." B";
 }
 else if($size < ; $mb)
 {
 return round($size/$kb,2)." KB";
 }
 else if($size < $gb)
 {
 return round($size/$mb,2) ." MB";
 }
 else if($size < $tb)
 {
 return round($size/$gb,2)." GB";
 }
 else
 {
 return round($size/ $tb,2)." TB";
 }
 }
 echo getRealSize(getDirSize('Directory'));
?>