php "mode" how to make links?

Question

I am workin on my website, and am running phpbb. I would like to have buttons on different parts of my site to redirect to the register, forgot password, account, and other things. However, the different urls for these arn't different files, but are different modes. How do I translate these different modes into links for a herf? Some examples of this mode url from my site is /ucp.php?mode=register and /ucp.php?mode=sendpassword.

Here is the code for ucp.php:

<?php
/**
*

* @package ucp
* @version $Id$
* @copyright (c) 2005 phpBB Group
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*
*/
session_start();
/**
* @ignore
*/
define('IN_PHPBB', true);
$phpbb_root_path = (defined('PHPBB_ROOT_PATH')) ? PHPBB_ROOT_PATH : './';
$phpEx = substr(strrchr(__FILE__, '.'), 1);
require($phpbb_root_path . 'common.' . $phpEx);
require($phpbb_root_path . 'includes/functions_user.' . $phpEx);
require($phpbb_root_path . 'includes/functions_module.' . $phpEx);

// Basic parameter data
$id     = request_var('i', '');
$mode   = request_var('mode', '');

if (in_array($mode, array('login', 'logout', 'confirm', 'sendpassword', 'activate')))
{
    define('IN_LOGIN', true);
}

// Start session management
$user->session_begin();
$auth->acl($user->data);
$user->setup('ucp');

// Setting a variable to let the style designer know where he is...
$template->assign_var('S_IN_UCP', true);

$module = new p_master();
$default = false;

// Basic "global" modes
switch ($mode)
{
    case 'activate':
        $module->load('ucp', 'activate');
        $module->display($user->lang['UCP_ACTIVATE']);

        redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
    break;

    case 'resend_act':
        $module->load('ucp', 'resend');
        $module->display($user->lang['UCP_RESEND']);
    break;

    case 'sendpassword':
        $module->load('ucp', 'remind');
        $module->display($user->lang['UCP_REMIND']);
    break;

    case 'register':
        if ($user->data['is_registered'] || isset($_REQUEST['not_agreed']))
        {
            redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
        }

        $module->load('ucp', 'register');
        $module->display($user->lang['REGISTER']);
    break;

    case 'confirm':
        $module->load('ucp', 'confirm');
    break;

    case 'login':
        if ($user->data['is_registered'])
        {
            redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
        }

        login_box(request_var('redirect', "index.$phpEx"));
    break;

    case 'logout':
        if ($user->data['user_id'] != ANONYMOUS && isset($_GET['sid']) && !is_array($_GET['sid']) && $_GET['sid'] === $user->session_id)
        {
            $user->session_kill();
            $user->session_begin();
            $message = $user->lang['LOGOUT_REDIRECT'];
        }
        else
        {
            $message = ($user->data['user_id'] == ANONYMOUS) ? $user->lang['LOGOUT_REDIRECT'] : $user->lang['LOGOUT_FAILED'];
        }
        meta_refresh(3, append_sid("{$phpbb_root_path}index.$phpEx"));

        $message = $message . '<br /><br />' . sprintf($user->lang['RETURN_INDEX'], '<a href="' . append_sid("{$phpbb_root_path}index.$phpEx") . '">', '</a> ');
        trigger_error($message);

    break;

    case 'terms':
    case 'privacy':

        $message = ($mode == 'terms') ? 'TERMS_OF_USE_CONTENT' : 'PRIVACY_POLICY';
        $title = ($mode == 'terms') ? 'TERMS_USE' : 'PRIVACY';

        if (empty($user->lang[$message]))
        {
            if ($user->data['is_registered'])
            {
                redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
            }

            login_box();
        }

        $template->set_filenames(array(
            'body'      => 'ucp_agreement.html')
        );

        // Disable online list
        page_header($user->lang[$title], false);

        $template->assign_vars(array(
            'S_AGREEMENT'           => true,
            'AGREEMENT_TITLE'       => $user->lang[$title],
            'AGREEMENT_TEXT'        => sprintf($user->lang[$message], $config['sitename'], generate_board_url()),
            'U_BACK'                => append_sid("{$phpbb_root_path}ucp.$phpEx", 'mode=login'),
            'L_BACK'                => $user->lang['BACK_TO_LOGIN'],
        ));

        page_footer();

    break;

    case 'delete_cookies':

        // Delete Cookies with dynamic names (do NOT delete poll cookies)
        if (confirm_box(true))
        {
            $set_time = time() - 31536000;

            foreach ($_COOKIE as $cookie_name => $cookie_data)
            {
                // Only delete board cookies, no other ones...
                if (strpos($cookie_name, $config['cookie_name'] . '_') !== 0)
                {
                    continue;
                }

                $cookie_name = str_replace($config['cookie_name'] . '_', '', $cookie_name);

                // Polls are stored as {cookie_name}_poll_{topic_id}, cookie_name_ got removed, therefore checking for poll_
                if (strpos($cookie_name, 'poll_') !== 0)
                {
                    $user->set_cookie($cookie_name, '', $set_time);
                }
            }

            $user->set_cookie('track', '', $set_time);
            $user->set_cookie('u', '', $set_time);
            $user->set_cookie('k', '', $set_time);
            $user->set_cookie('sid', '', $set_time);

            // We destroy the session here, the user will be logged out nevertheless
            $user->session_kill();
            $user->session_begin();

            meta_refresh(3, append_sid("{$phpbb_root_path}index.$phpEx"));

            $message = $user->lang['COOKIES_DELETED'] . '<br /><br />' . sprintf($user->lang['RETURN_INDEX'], '<a href="' . append_sid("{$phpbb_root_path}index.$phpEx") . '">', '</a>');
            trigger_error($message);
        }
        else
        {
            confirm_box(false, 'DELETE_COOKIES', '');
        }

        redirect(append_sid("{$phpbb_root_path}index.$phpEx"));

    break;

    case 'switch_perm':

        $user_id = request_var('u', 0);

        $sql = 'SELECT *
            FROM ' . USERS_TABLE . '
            WHERE user_id = ' . (int) $user_id;
        $result = $db->sql_query($sql);
        $user_row = $db->sql_fetchrow($result);
        $db->sql_freeresult($result);

        if (!$auth->acl_get('a_switchperm') || !$user_row || $user_id == $user->data['user_id'] || !check_link_hash(request_var('hash', ''), 'switchperm'))
        {
            redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
        }

        include($phpbb_root_path . 'includes/acp/auth.' . $phpEx);

        $auth_admin = new auth_admin();
        if (!$auth_admin->ghost_permissions($user_id, $user->data['user_id']))
        {
            redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
        }

        add_log('admin', 'LOG_ACL_TRANSFER_PERMISSIONS', $user_row['username']);

        $message = sprintf($user->lang['PERMISSIONS_TRANSFERRED'], $user_row['username']) . '<br /><br />' . sprintf($user->lang['RETURN_INDEX'], '<a href="' . append_sid("{$phpbb_root_path}index.$phpEx") . '">', '</a>');
        trigger_error($message);

    break;

    case 'restore_perm':

        if (!$user->data['user_perm_from'] || !$auth->acl_get('a_switchperm'))
        {
            redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
        }

        $auth->acl_cache($user->data);

        $sql = 'SELECT username
            FROM ' . USERS_TABLE . '
            WHERE user_id = ' . $user->data['user_perm_from'];
        $result = $db->sql_query($sql);
        $username = $db->sql_fetchfield('username');
        $db->sql_freeresult($result);

        add_log('admin', 'LOG_ACL_RESTORE_PERMISSIONS', $username);

        $message = $user->lang['PERMISSIONS_RESTORED'] . '<br /><br />' . sprintf($user->lang['RETURN_INDEX'], '<a href="' . append_sid("{$phpbb_root_path}index.$phpEx") . '">', '</a>');
        trigger_error($message);

    break;

    default:
        $default = true;
    break;
}

// We use this approach because it does not impose large code changes
if (!$default)
{
    return true;
}

// Only registered users can go beyond this point
if (!$user->data['is_registered'])
{
    if ($user->data['is_bot'])
    {
        redirect(append_sid("{$phpbb_root_path}index.$phpEx"));
    }

    if ($id == 'pm' && $mode == 'view' && isset($_GET['p']))
    {
        $redirect_url = append_sid("{$phpbb_root_path}ucp.$phpEx?i=pm&p=" . request_var('p', 0));
        login_box($redirect_url, $user->lang['LOGIN_EXPLAIN_UCP']);
    }

    login_box('', $user->lang['LOGIN_EXPLAIN_UCP']);
}

// Instantiate module system and generate list of available modules
$module->list_modules('ucp');

// Check if the zebra module is set
if ($module->is_active('zebra', 'friends'))
{
    // Output listing of friends online
    $update_time = $config['load_online_time'] * 60;

    $sql = $db->sql_build_query('SELECT_DISTINCT', array(
        'SELECT'    => 'u.user_id, u.username, u.username_clean, u.user_colour, MAX(s.session_time) as online_time, MIN(s.session_viewonline) AS viewonline',

        'FROM'      => array(
            USERS_TABLE     => 'u',
            ZEBRA_TABLE     => 'z'
        ),

        'LEFT_JOIN' => array(
            array(
                'FROM'  => array(SESSIONS_TABLE => 's'),
                'ON'    => 's.session_user_id = z.zebra_id'
            )
        ),

        'WHERE'     => 'z.user_id = ' . $user->data['user_id'] . '
            AND z.friend = 1
            AND u.user_id = z.zebra_id',

        'GROUP_BY'  => 'z.zebra_id, u.user_id, u.username_clean, u.user_colour, u.username',

        'ORDER_BY'  => 'u.username_clean ASC',
    ));

    $result = $db->sql_query($sql);

    while ($row = $db->sql_fetchrow($result))
    {
        $which = (time() - $update_time < $row['online_time'] && ($row['viewonline'] || $auth->acl_get('u_viewonline'))) ? 'online' : 'offline';

        $template->assign_block_vars("friends_{$which}", array(
            'USER_ID'       => $row['user_id'],

            'U_PROFILE'     => get_username_string('profile', $row['user_id'], $row['username'], $row['user_colour']),
            'USER_COLOUR'   => get_username_string('colour', $row['user_id'], $row['username'], $row['user_colour']),
            'USERNAME'      => get_username_string('username', $row['user_id'], $row['username'], $row['user_colour']),
            'USERNAME_FULL' => get_username_string('full', $row['user_id'], $row['username'], $row['user_colour']))
        );
    }
    $db->sql_freeresult($result);
}

// Do not display subscribed topics/forums if not allowed
if (!$config['allow_topic_notify'] && !$config['allow_forum_notify'])
{
    $module->set_display('main', 'subscribed', false);
}

// Do not display signature panel if not authed to do so
if (!$auth->acl_get('u_sig'))
{
    $module->set_display('profile', 'signature', false);
}

// Select the active module
$module->set_active($id, $mode);

// Load and execute the relevant module
$module->load_active();

// Assign data to the template engine for the list of modules
$module->assign_tpl_vars(append_sid("{$phpbb_root_path}ucp.$phpEx"));

// Generate the page, do not display/query online list
$module->display($module->get_page_title(), false);

/**
* Function for assigning a template var if the zebra module got included
*/
function _module_zebra($mode, &$module_row)
{
    global $template;

    $template->assign_var('S_ZEBRA_ENABLED', true);

    if ($mode == 'friends')
    {
        $template->assign_var('S_ZEBRA_FRIENDS_ENABLED', true);
    }

    if ($mode == 'foes')
    {
        $template->assign_var('S_ZEBRA_FOES_ENABLED', true);
    }
}

?>

Answer 1

search for $mode == within the code, and you will be able to see each of the different modes available. For ucp.php, you can find terms, view, friends, foes, which translate to:

/ucp.php?mode=terms
/ucp.php?mode=view
/ucp.php?mode=friends
/ucp.php?mode=foes

if you look for the arguments within the file, you will be able to create these links by linking to the correct file with the correct argument.