<?php
function find_common_php() {
    $current_dir = dirname(__FILE__);
    $parent_dir = "../";
    $count = 0;
    while (!file_exists($current_dir . "/common.php")) {
        $current_dir = dirname($current_dir);
        $count++;
        if ($current_dir === '/' || $current_dir === '.') {
            break;
        }
    }
    return $count;
}
$up_count = find_common_php();
$include_path = str_repeat('../', $up_count) . 'common.php';
include_once($include_path);