只是大致分析下執行流程，主要就是取得mod參數的值，根據取值加載控制器，控制器位置在最后一行指定了。

1 ）定義應用名稱，加載兩個必要文件

define('Aphp';//核心類require './source/function/function_forum.php';//論壇函數庫

2 ）modarray數組限定了mod取值范圍

$modarray = array('Ajax','announcement','attachment','forumdisplay',    'group','image','index','medal','misc','modcp','notice','post','redirect',    'relatekw','relatethread','rss','topicadmin','trade','viewthread','tag','collection','guide');//模塊緩存列表,各個子數組分別表示各個模塊要緩存的緩存項$modcachelist = array(    'index'        => array('announcements', 'onlinelist', 'forumlinks',            'heats', 'historyposts', 'onlinerecord', 'userstats', 'diytemplatenameforum'),    'forumdisplay'    => array('smilies', 'announcements_forum', 'globalstick', 'forums',            'onlinelist', 'forumstick', 'threadtable_info', 'threadtableids', 'stamps', 'diytemplatenameforum'),    'viewthread'    => array('smilies', 'smileytypes', 'forums', 'usergroups',            'stamps', 'bbcodes', 'smilies',    'custominfo', 'groupicon', 'stamps',            'threadtableids', 'threadtable_info', 'posttable_info', 'diytemplatenameforum'),    'redirect'    => array('threadtableids', 'threadtable_info', 'posttable_info'),    'post'        => array('bbcodes_display', 'bbcodes', 'smileycodes', 'smilies', 'smileytypes',            'domainwhitelist', 'albumcategory'),    'space'        => array('fields_required', 'fields_optional', 'custominfo'),    'group'        => array('grouptype', 'diytemplatenamegroup'),);

3 ）如果mod參數為空或者不合法都會讓表達式為真，導致值為index

$mod = !in_array(C::app()->var['mod'], $modarray) ? 'index' : C::app()->var['mod'];

4 ）做初始化

define('CURMODULE', $mod);//var_dump(CURMODULE);$cachelist = array();if(isset($modcachelist[CURMODULE])) {//如果當前緩存項存在的話，    $cachelist = $modcachelist[CURMODULE];//獲取當前緩存組的緩存列表項    $cachelist[] = 'plugin';    $cachelist[] = 'pluginlanguage_system';}if(C::app()->var['mod'] == 'group') {    $_G['basescript'] = 'group';}C::app()->cachelist = $cachelist;C::app()->init();//初始化loadforum();set_rssauth();runhooks();

5 ）加載控制器

$navtitle = str_replace('{bbname}', $_G['setting']['bbname'], $_G['setting']['SEOtitle']['forum']);$_G['setting']['threadhidethreshold'] = 1;//var_dump($mod);require DISCUZ_ROOT.'./source/module/forum/forum_'.$mod.'.php';