<?php
$dir = '~/public_html/files';
$dp = opendir($dir);
$files = array();
if ($dp) {
    while ($file = readdir($dp)) {
        if (is_dir("$dir$file")) {
            $innerdp = opendir("$dir$file");
            if ($innerdp) {
                while ($innerfile = readdir($innerdp)) {
                    $files[$file][] = $innerfile;
                }
            }
        }
    }
}
?>