Retrieve the size of all files in an directory

function dir_size($path)
{

// use a normalize_path function here
// to make sure $path contains an
// ending slash
// (-> http://codedump.jonasjohn.de/snippets/normalize_path.htm)

// to display a good lucking size you can use a readable_filesize
// function, get it here:
// (-> http://codedump.jonasjohn.de/snippets/readable_filesize.htm)

$size = 0;

$dir = opendir($path);
if (!$dir){return 0;}

while (($file = readdir($dir)) !== false) {

if ($file[0] == '.'){ continue; }

if (is_dir($path.$file)){
// recursive:
$size += dir_size($path.$file.DIRECTORY_SEPARATOR);
}
else {
$size += filesize($path.$file);
}
}

closedir($dir);
return $size;
}