Create file directory structure for downloadable Magento products & move files accordingly

generate-file-dirs.php

<?php
foreach (new DirectoryIterator('files/') as $file) {
    if ($file->isFile()) {
        $file_name  = $file->getFilename();
        $name       = strtolower($file_name);
        $letter1    = $name[0];
        $letter2    = $name[1];
        
        // Create first directory
        if (!file_exists('media/downloadable/files/links/' . $letter1)) {
            mkdir('media/downloadable/files/links/' . $letter1, 0777, true);
        }
        
        // Create subdirectory
        if (!file_exists('media/downloadable/files/links/' . $letter1 . '/' . $letter2)) {
            mkdir('media/downloadable/files/links/' . $letter1 . '/' . $letter2, 0777, true);
        }
        
        // Move file
        rename('files/' . $file_name, 'media/downloadable/files/links/' . $letter1 . '/' . $letter2 . '/' . $name);
    }
}
?>