moodle/backup/restore_precheck.html

<?php
    //This page copies th zip to the temp directory,
    //unzip it, check that it is a valid backup file
    //inform about its contents and fill all the necesary
    //variables to continue with the restore.

    //Checks we have the file variable
    if (!isset($file)) {
        print_error('nofile');
    }

    //Check login
    require_login();

    $loginurl = get_login_url();

    //Check admin
    if (!empty($id)) {
        if (!has_capability('moodle/restore:restorecourse', get_context_instance(CONTEXT_COURSE, $id))) {
            if (empty($to)) {
                print_error("cannotuseadminadminorteacher", '', $loginurl);
            } else {
                if (!has_capability('moodle/restore:restorecourse', get_context_instance(CONTEXT_COURSE, $to))
                    && !has_capability('moodle/restore:restoretargetimport',  get_context_instance(CONTEXT_COURSE, $to))) {
                    print_error("cannotuseadminadminorteacher", '', $loginurl);
                }
            }
        }
    } else {
        if (!has_capability('moodle/restore:restorecourse', get_context_instance(CONTEXT_SYSTEM))) {
            print_error("cannotuseadmin", '', $loginurl);
        }
    }

    //Check site
    $site = get_site();

    $errorstr = '';
    if (!empty($SESSION->restore->importing)) {
        define('RESTORE_SILENTLY',true);
    }
    $status = restore_precheck($id,$file,$errorstr);

    if (!$status) {
        print_error("pleasereport");
    }