directory - Remove empty subfolders with PHP

Question

I am working on a PHP function that will recursively remove all sub-folders that contain no files starting from a given absolute path.

Here is the code developed so far:

function RemoveEmptySubFolders($starting_from_path) {

    // Returns true if the folder contains no files
    function IsEmptyFolder($folder) {
        return (count(array_diff(glob($folder.DIRECTORY_SEPARATOR."*"), Array(".", ".."))) == 0);
    }

    // Cycles thorugh the subfolders of $from_path and
    // returns true if at least one empty folder has been removed
    function DoRemoveEmptyFolders($from_path) {
        if(IsEmptyFolder($from_path)) {
            rmdir($from_path);
            return true;
        }
        else {
            $Dirs = glob($from_path.DIRECTORY_SEPARATOR."*", GLOB_ONLYDIR);
            $ret = false;
            foreach($Dirs as $path) {
                $res = DoRemoveEmptyFolders($path);
                $ret = $ret ? $ret : $res;
            }
            return $ret;
        }
    }

    while (DoRemoveEmptyFolders($starting_from_path)) {}
}

As per my tests this function works, though I would be very delighted to see any ideas for better performing code.

Answer 1

If you have empty folder within empty folder within empty folder, you'll need to loop through ALL folders three times. All this, because you go breadth first - test folder BEFORE testing its children. Instead, you should go into child folders before testing if parent is empty, this way one pass will be sufficient.

function RemoveEmptySubFolders($path)
{
  $empty=true;
  foreach (glob($path.DIRECTORY_SEPARATOR."*") as $file)
  {
     if (is_dir($file))
     {
        if (!RemoveEmptySubFolders($file)) $empty=false;
     }
     else
     {
        $empty=false;
     }
  }
  if ($empty) rmdir($path);
  return $empty;
}

By the way, glob does not return . and .. entries.

Shorter version:

function RemoveEmptySubFolders($path)
{
  $empty=true;
  foreach (glob($path.DIRECTORY_SEPARATOR."*") as $file)
  {
     $empty &= is_dir($file) && RemoveEmptySubFolders($file);
  }
  return $empty && rmdir($path);
}