哪位高手能说明一下discuz X2.5 upload/index.php文件思路！
discuz X2.5 upload/index.php代码如下，主说针对运行步骤（架构思路）说明一下，越详细越好，非常感谢！！！
discuz
<?php
/**
* [Discuz!] (C)2001-2099 Comsenz Inc.
* This is NOT a freeware, use is subject to license terms
*
* $Id: index.php 27617 2012-02-07 08:24:14Z monkey $
*/
if(!empty($_SERVER['QUERY_STRING']) && is_numeric($_SERVER['QUERY_STRING'])) {
$_ENV['curapp'] = 'home';
$_GET = array('mod'=>'space', 'uid'=>$_SERVER['QUERY_STRING']);
} else {
$url = '';
$domain = $_ENV = array();
$jump = false;
@include_once './data/sysdata/cache_domain.php';
$_ENV['domain'] = $domain;
if(empty($_ENV['domain'])) {
$_ENV['curapp'] = 'forum';
} else {
$_ENV['defaultapp'] = array('portal.php' => 'portal', 'forum.php' => 'forum', 'group.php' => 'group', 'home.php' => 'home');
$_ENV['hostarr'] = explode('.', $_SERVER['HTTP_HOST']);
$_ENV['domainroot'] = substr($_SERVER['HTTP_HOST'], strpos($_SERVER['HTTP_HOST'], '.')+1);
if(!empty($_ENV['domain']['app']) && is_array($_ENV['domain']['app']) && in_array($_SERVER['HTTP_HOST'], $_ENV['domain']['app'])) {
$_ENV['curapp'] = array_search($_SERVER['HTTP_HOST'], $_ENV['domain']['app']);
if($_ENV['curapp'] == 'mobile') {
$_ENV['curapp'] = 'forum';
if(@$_GET['mobile'] != 'no') {
@$_GET['mobile'] = 'yes';
}
}
if($_ENV['curapp'] == 'default' || !isset($_ENV['defaultapp'][$_ENV['curapp'].'.php'])) {
$_ENV['curapp'] = '';
}
} elseif(!empty($_ENV['domain']['root']) && is_array($_ENV['domain']['root']) && in_array($_ENV['domainroot'], $_ENV['domain']['root'])) {
$_G['setting']['holddomain'] = $_ENV['domain']['holddomain'] ? $_ENV['domain']['holddomain'] : array('www');
$list = $_ENV['domain']['list'];
if(isset($list[$_SERVER['HTTP_HOST']])) {
$domain = $list[$_SERVER['HTTP_HOST']];
$id = intval($domain['id']);
switch($domain['idtype']) {
case 'subarea':
$_ENV['curapp'] = 'forum';
$_GET['gid'] = $id;
break;
case 'forum':
$_ENV['curapp'] = 'forum';
$_GET['mod'] = 'forumdisplay';
$_GET['fid'] = $id;
break;
case 'topic':
$_ENV['curapp'] = 'portal';
$_GET['mod'] = 'topic';
$_GET['topicid'] = $id;
break;
case 'channel':
$_ENV['curapp'] = 'portal';
$_GET['mod'] = 'list';
$_GET['catid'] = $id;
break;
}
} elseif(count($_ENV['hostarr']) > 2 && $_ENV['hostarr'][0] != 'www' && !checkholddomain($_ENV['hostarr'][0])) {
$_ENV['prefixdomain'] = addslashes($_ENV['hostarr'][0]);
$_ENV['domainroot'] = addslashes($_ENV['domainroot']);
require_once './source/class/class_core.php';
C::app()->init_setting = true;
C::app()->init_user = false;
C::app()->init_session = false;
C::app()->init_cron = false;
C::app()->init_misc = false;
C::app()->init();
$jump = true;
$domain = C::t('common_domain')->fetch_by_domain_domainroot($_ENV['prefixdomain'], $_ENV['domainroot']);
$apphost = $_ENV['domain']['app'][$domain['idtype']] ? $_ENV['domain']['app'][$domain['idtype']] : $_ENV['domain']['app']['default'];
$apphost = $apphost ? 'http://'.$apphost.'/' : '';
switch($domain['idtype']) {
case 'home':
if($_G['setting']['rewritestatus'] && in_array('home_space', $_G['setting']['rewritestatus'])) {
$url = rewriteoutput('home_space', 1, $apphost, $domain['id']);
} else {
$url = $apphost.'home.php?mod=space&uid='.$domain['id'];
}
break;
case 'group':
if($_G['setting']['rewritestatus'] && in_array('group_group', $_G['setting']['rewritestatus'])) {
$url = rewriteoutput('group_group', 1, $apphost, $domain['id']);
} else {
$url = $apphost.'forum.php?mod=group&fid='.$domain['id'].'&page=1';
}
break;
}
}
} else {
$jump = true;
}
if(empty($url) && empty($_ENV['curapp'])) {
if(!empty($_ENV['domain']['defaultindex']) && !$jump) {
if($_ENV['defaultapp'][$_ENV['domain']['defaultindex']]) {
$_ENV['curapp'] = $_ENV['defaultapp'][$_ENV['domain']['defaultindex']];
} else {
$url = $_ENV['domain']['defaultindex'];
}
} else {
if($jump) {
$url = empty($_ENV['domain']['app']['default']) ? (!empty($_ENV['domain']['defaultindex']) ? $_ENV['domain']['defaultindex'] : 'forum.php') : 'http://'.$_ENV['domain']['app']['default'];
} else {
$_ENV['curapp'] = 'forum';
}
}
}
}
}
if(!empty($url)) {
$delimiter = strrpos($url, '?') ? '&' : '?';
if(isset($_GET['fromuid']) && $_GET['fromuid']) {
$url .= $delimiter.'fromuid='.$_GET['fromuid'];
} elseif(isset($_GET['fromuser']) && $_GET['fromuser']) {
$url .= $delimiter.'fromuser='.$_GET['fromuser'];
}
header("HTTP/1.1 301 Moved Permanently");
header("location: $url");
} else {
require './'.$_ENV['curapp'].'.php';
}
function checkholddomain($domain) {
global $_G;
$domain = strtolower($domain);
if(preg_match("/^[^a-z]/i", $domain)) return true;
$holdmainarr = empty($_G['setting']['holddomain']) ? array('www') : explode('|', $_G['setting']['holddomain']);
$ishold = false;
foreach ($holdmainarr as $value) {
if(strpos($value, '*') === false) {
if(strtolower($value) == $domain) {
$ishold = true;
break;
}
} else {
$value = str_replace('*', '.*?', $value);
if(@preg_match("/$value/i", $domain)) {
$ishold = true;
break;
}
}
}
return $ishold;
}
?>
