Adiciona um hash e/outras coisas no arquivo enviado

hash_for_uploads.php

<?php

function make_filename_hash($filename) {
    $nomedosite = get_bloginfo('name');
    $info = pathinfo($filename);
    $ext  = empty($info['extension']) ? '' : '.' . $info['extension'];
    $name = basename($filename, $ext);
    return $nomedosite.'_'.md5($name) . $ext;
}
add_filter('sanitize_file_name', 'make_filename_hash', 10);

;?>