/*
[Discuz!] (C)2001-2007 Comsenz Inc.
This is NOT a freeware, use is subject to license terms
$Id: index.php 13764 2008-05-19 03:14:01Z heyond $
*/
define(\'CURSCRIPT\', \'index\');//定义当前运行脚本名
require_once \'./include/common.inc.php\';//引入common文件
require_once DISCUZ_ROOT.\'./include/forum.func.php\';//引入版块处理函数forum.func.php
$discuz_action = 1;//?
if($cacheindexlife && !$discuz_uid && $showoldetails != \'yes\' && (!$_DCACHE[\'settings\'][\'frameon\'] || $_DCACHE[\'settings\'][\'frameon\'] && $_GET[\'frameon\'] != \'yes\') && emptyempty($gid)) {
//分析：$cacheindexlife-首页缓存有效期，$discuz_uid存在，$showoldetails-显示在线详情，$_DCACHE[\'settings\'][\'frameon\']-左右分栏模式开关，$gid-版块组id，自己看看吧，大概就是判断是否使用一个静态htm页面的条件，这个由后台是否开启首页缓存时间来决定的
$indexcache = getcacheinfo(0);//得到首页缓存，此函数见include/forum.func.php 157行，主要是处理index.htm
//下面一段就是判断是否过期咯，如果过期，就删除index.htm，否则读取文件，并根据系统配置决定是否显示debug信息
if($timestamp - $indexcache[\'filemtime\'] > $cacheindexlife) {
@unlink($indexcache[\'filename\']);
define(\'CACHE_FILE\', $indexcache[\'filename\']);
$styleid = $_DCACHE[\'settings\'][\'styleid\'];
} elseif($indexcache[\'filename\']) {
@readfile($indexcache[\'filename\']);
$debug && debuginfo();
$debug ? die(\'<mce:script type="text/javascript"><!--
document.getElementById("debuginfo").innerHTML = " \'.($debug ? \'Updated at \'.gmdate("H:i:s", $indexcache[\'filemtime\'] + 3600 * 8).\', Processed in \'.$debuginfo[\'time\'].\' second(s), \'.$debuginfo[\'queries\'].\' Queries\'.($gzipcompress ? \', Gzip enabled\' : \'\') : \'\').\'";
// --></mce:script>\') : die();
}
}
//$validdays?用户组有效时间？
$validdays = $discuz_uid && !emptyempty($groupexpiry) && $groupexpiry >= $timestamp ? ceil(($groupexpiry - $timestamp) / 86400) : 0;
//是否显示在线情况
if(isset($showoldetails)) {
switch($showoldetails) {
case \'no\': dsetcookie(\'onlineindex\', 0, 86400 * 365); break;
case \'yes\': dsetcookie(\'onlineindex\', 1, 86400 * 365); break;
}
} else {
$showoldetails = false;
}
$currenttime = gmdate($timeformat, $timestamp + $timeoffset * 3600);//当前时间
$lastvisittime = gmdate("$dateformat $timeformat", $lastvisit + $timeoffset * 3600);//上次访问时间
$memberenc = rawurlencode($lastmember);//最后注册用户-对URL进行了编码
$newthreads = round(($timestamp - $lastvisit + 600) / 1000) * 1000;//这个变量不知道干啥的？
$rsshead = $rssstatus ? (\'<link rel="alternate" type="application/rss+xml" title="\'.$bbname.\'" href="\'.$boardurl.\'rss.php?auth=\'.$rssauth." mce_href="\'.$boardurl.\'rss.php?auth=\'.$rssauth."\" />\n") : \'\';//rss的链接
$customtopics = \'\';
if($qihoo[\'maxtopics\']) {
foreach(explode("\t", isset($_DCOOKIE[\'customkw\']) ? $_DCOOKIE[\'customkw\'] : \'\') as $topic) {
$topic = dhtmlspecialchars(trim(stripslashes($topic)));
$customtopics .= \'<a href="topic.php?keyword=\'.rawurlencode($topic).\'" mce_href="topic.php?keyword=\'.rawurlencode($topic).\'" target="_blank">\'.$topic.\'</a> \';
}
}//以上两段，qihoo专题？-后台的扩展-qihoo搜索那里可以设置
$hottagstatus = $tagstatus && $hottags && $_DCACHE[\'tags\'];//显示热门标签
$catlist = $forumlist = $sublist = $forumname = $collapseimg = $collapse = array();//初始化区、版块、子版等数组
$threads = $posts = $todayposts = $fids = $announcepm = 0;//初始化帖子、回复、今日回复、版块id等数组
$postdata = $historyposts ? explode("\t", $historyposts) : array();//历史发帖？
foreach(array(\'forumlinks\', \'birthdays\') as $key) {//处理友情链接与生日用户的显示
if(!isset($_COOKIE[\'discuz_collapse\']) || strpos($_COOKIE[\'discuz_collapse\'], $key) === FALSE) {
$collapseimg[$key] = \'collapsed_no.gif\';
$collapse[$key] = \'\';
} else {
$collapseimg[$key] = \'collapsed_yes.gif\';
$collapse[$key] = \'display: none\';
}
}
$gid = !emptyempty($gid) ? intval($gid) : 0;//区显示方式
if(!$gid) {//如果不是区显示方式，即默认的显示所有版块的首页
$announcements = \'\';//此句与下面一段是处理论坛公告
if($_DCACHE[\'announcements\']) {
$readapmids = !emptyempty($_DCOOKIE[\'readapmid\']) ? explode(\'D\', $_DCOOKIE[\'readapmid\']) : array();
foreach($_DCACHE[\'announcements\'] as $announcement) {
if(emptyempty($announcement[\'groups\']) || in_array($groupid, $announcement[\'groups\'])) {
if(emptyempty($announcement[\'type\'])) {
$announcements .= \'<li><a href="announcement.php?id=\'.$announcement[\'id\'].\'" mce_href="announcement.php?id=\'.$announcement[\'id\'].\'">\'.$announcement[\'subject\'].
\'<i>(\'.gmdate($dateformat, $announcement[\'starttime\'] + $timeoffset * 3600).\')</i></a></li>\';
} elseif($announcement[\'type\'] == 1) {
$announcements .= \'<li><a href="\'.$announcement[\'message\'].\'" mce_href="\'.$announcement[\'message\'].\'" target="_blank">\'.$announcement[\'subject\'].
\'<i>(\'.gmdate($dateformat, $announcement[\'starttime\'] + $timeoffset * 3600).\')</i></a></li>\';
}
}
}
}
unset($_DCACHE[\'announcements\']);//得到公告的字符串后，及时清空这个公告数组
//选出论坛列表的sql，注意这里判断了是否有访问限制，如果$accessmasks不为空，则根据某用户的特殊访问规则选出了 a.allowview这个字段等
$sql = !emptyempty($accessmasks) ?
"SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect, a.allowview FROM {$tablepre}forums f
LEFT JOIN {$tablepre}forumfields ff ON ff.fid=f.fid
LEFT JOIN {$tablepre}access a ON a.uid=\'$discuz_uid\' AND a.fid=f.fid
WHERE f.status>0 ORDER BY f.type, f.displayorder"
: "SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect FROM {$tablepre}forums f
LEFT JOIN {$tablepre}forumfields ff USING(fid)
WHERE f.status>0 ORDER BY f.type, f.displayorder";
$query = $db->query($sql);
while($forum = $db->fetch_array($query)) {//从这里开始得到两个重要数组$catlist $forumlist，保存区信息与版块列表信息
$forumname[$forum[\'fid\']] = strip_tags($forum[\'name\']);//去掉html与php标记，并存入$forumname数组，以fid为键
if($forum[\'type\'] != \'group\') {//如果是普通版块(如type=forum或forum=sub)而不是分区
$threads += $forum[\'threads\'];//主题总数
$posts += $forum[\'posts\'];//帖子总数(主题与回复)
$todayposts += $forum[\'todayposts\'];//今日帖子
if($forum[\'type\'] == \'forum\') {//非最终子版(即type不等于sub和group)的版块
if(forum($forum)) {//forum函数来自include/forum.func.php，处理版块，得到比如版主啊图标啊什么的
$catlist[$forum[\'fup\']][\'forums\'][] = $forum[\'fid\'];//分区数组$catlist更新
$forum[\'orderid\'] = $catlist[$forum[\'fup\']][\'forumscount\']++;//得到版块的排序，所在分区的版块总数加1，每得到一个子版，就自增1
$forum[\'subforums\'] = \'\';//将子版字符串设置为空的，这里不是很明白，forum函数里得到了一个相同名的字符串，这里为何要清空？
$forumlist[$forum[\'fid\']] = $forum;//将$forum数组赋值给$forumlist的一个元素
}
} elseif(isset($forumlist[$forum[\'fup\']])) {//如果此版块的父版块id在$forumlist中存在(由上面的if中得到)，则
$forumlist[$forum[\'fup\']][\'threads\'] += $forum[\'threads\'];
$forumlist[$forum[\'fup\']][\'posts\'] += $forum[\'posts\'];
$forumlist[$forum[\'fup\']][\'todayposts\'] += $forum[\'todayposts\'];//累加三个值
if($subforumsindex && $forumlist[$forum[\'fup\']][\'permission\'] == 2 && !($forumlist[$forum[\'fup\']][\'simple\'] & 16) || ($forumlist[$forum[\'fup\']][\'simple\'] & 8)) {
$forumlist[$forum[\'fup\']][\'subforums\'] .= \'<a href="forumdisplay.php?fid=\'.$forum[\'fid\'].\'" mce_href="forumdisplay.php?fid=\'.$forum[\'fid\'].\'">\'.$forum[\'name\'].\'</a> \';
}//对版块的子版字符串进行处理
}
} else {//否则，如果是分区
if(!isset($_COOKIE[\'discuz_collapse\']) || strpos($_COOKIE[\'discuz_collapse\'], \'category_\'.$forum[\'fid\']) === FALSE) {
$forum[\'collapseimg\'] = \'collapsed_no.gif\';
$collapse[\'category_\'.$forum[\'fid\']] = \'\';
} else {
$forum[\'collapseimg\'] = \'collapsed_yes.gif\';
$collapse[\'category_\'.$forum[\'fid\']] = \'display: none\';
}//上面是对分区开启关闭按钮的处理？
if($forum[\'moderators\']) {
$forum[\'moderators\'] = moddisplay($forum[\'moderators\'], \'flat\');
}//区版主
$forum[\'forumscount\'] = 0;
$catlist[$forum[\'fid\']] = $forum;//更新区版块数组
}
}
foreach($catlist as $catid => $category) {//对分区的显示进行处理，如表格宽度，是否横排版块等等
if($catlist[$catid][\'forumscount\'] && $category[\'forumcolumns\']) {
$catlist[$catid][\'forumcolwidth\'] = floor(100 / $category[\'forumcolumns\']).\'%\';
$catlist[$catid][\'endrows\'] = \'\';
if($colspan = $category[\'forumscount\'] % $category[\'forumcolumns\']) {
while(($category[\'forumcolumns\'] - $colspan) > 0) {
$catlist[$catid][\'endrows\'] .= \'<td> </td>\';
$colspan ++;
}
$catlist[$catid][\'endrows\'] .= \'</tr>\';
}
} elseif(emptyempty($category[\'forumscount\'])) {
unset($catlist[$catid]);
}
}
unset($catid, $category);
if(isset($catlist[0]) && $catlist[0][\'forumscount\']) {//0表示比分区更大一级的一个“虚拟分区”(暂时这么理解，因为有时候url中有fid=0这样的出现)
$catlist[0][\'fid\'] = 0;
$catlist[0][\'type\'] = \'group\';
$catlist[0][\'name\'] = $bbname;
$catlist[0][\'collapseimg\'] = \'collapsed_no.gif\';
} else {
unset($catlist[0]);
}
if($whosonlinestatus == 1 || $whosonlinestatus == 3) {//显示在线情况
$whosonlinestatus = 1;
$onlineinfo = explode("\t", $onlinerecord);//$onlineinfo变量,$onlinerecord来自index.php的extract($_DCACHE)处理
if(emptyempty($_DCOOKIE[\'onlineusernum\'])) {
$onlinenum = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions");//在线人数
if($onlinenum > $onlineinfo[0]) {//如果当前数据库中取得的在线人数大于原来在线人数，则更新$onlinerecord
$_DCACHE[\'settings\'][\'onlinerecord\'] = $onlinerecord = "$onlinenum\t$timestamp";
$db->query("UPDATE {$tablepre}settings SET value=\'$onlinerecord\' WHERE variable=\'onlinerecord\'");//同时更新settings表
require_once DISCUZ_ROOT.\'./include/cache.func.php\';
updatesettings();//更新settings缓存
$onlineinfo = array($onlinenum, $timestamp);//更新$onlineinfo数组
}
dsetcookie(\'onlineusernum\', intval($onlinenum), 300);//将在线人数写入cookie
} else {
$onlinenum = intval($_DCOOKIE[\'onlineusernum\']);//如果cookie中在线人数不为空，直接读出
}
$onlineinfo[1] = gmdate($dateformat, $onlineinfo[1] + ($timeoffset * 3600));//更新在线情况的时间戳
$detailstatus = $showoldetails == \'yes\' || (((!isset($_DCOOKIE[\'onlineindex\']) && !$whosonline_contract) || $_DCOOKIE[\'onlineindex\']) && $onlinenum < 500 && !$showoldetails);//判断在线详情变量，这里比较复杂，仔细看一下，主要是$showoldetails == \'yes\'与cookie中的首页显示啊 一些条件
if($detailstatus) {//以下是处理在线人数列表的
@include language(\'actions\');//引用语言文件 /templates/default/actions.lang.php
$discuz_uid && updatesession();//更新session
$membercount = $invisiblecount = 0;//初始化会员数量及隐身的数量
$whosonline = array();//初始化数组
$maxonlinelist = $maxonlinelist ? $maxonlinelist : 500;//最大在线人数，如果未设置，初始化为500
$query = $db->query("SELECT uid, username, groupid, invisible, action, lastactivity, fid FROM {$tablepre}sessions ".(isset($_DCACHE[\'onlinelist\'][7]) ? \'\' : \'WHERE uid <> 0\')." ORDER BY uid DESC LIMIT ".$maxonlinelist);
while($online = $db->fetch_array($query)) {
if($online[\'uid\']) {//会员
$membercount ++;//会员总数
if($online[\'invisible\']) {//隐身用户
$invisiblecount++;
continue;
} else {
$online[\'icon\'] = isset($_DCACHE[\'onlinelist\'][$online[\'groupid\']]) ? $_DCACHE[\'onlinelist\'][$online[\'groupid\']] : $_DCACHE[\'onlinelist\'][0];//用户组的图标
}
} else {//游客，区别是数据表session里，其uid为0
$online[\'icon\'] = $_DCACHE[\'onlinelist\'][7];
$online[\'username\'] = $_DCACHE[\'onlinelist\'][\'guest\'];
}
$online[\'fid\'] = $online[\'fid\'] ? $forumname[$online[\'fid\']] : 0;//用户正浏览版块？
$online[\'action\'] = $actioncode[$online[\'action\']];//用户正进行的动作
$online[\'lastactivity\'] = gmdate($timeformat, $online[\'lastactivity\'] + ($timeoffset * 3600));//用户上次访问？
$whosonline[] = $online;//赋值给$whosonline数组
}
unset($actioncode, $online);//清空两个变量
if($onlinenum > $maxonlinelist) {//如果总在线人数大于最大在线人数(系统默认为500)，分别取出已登录用户和隐身用户
$membercount = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions WHERE uid <> \'0\'");
$invisiblecount = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions WHERE invisible = \'1\'");
}
if($onlinenum < $membercount) {//如果总在线人数小于在线会员数，则更新cookie中的在线用户人数，注意是onlineusernum而不是onlinenum
$onlinenum = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions");
dsetcookie(\'onlineusernum\', intval($onlinenum), 300);
}
//总结：这里有些混乱，比如总在线人数，在线会员等等，因为变量类似，很容易看错理解错误，多看几遍吧。。。
$guestcount = $onlinenum - $membercount;
$db->free_result($query);//释放数据库连接
unset($online);//清空，230行不是有么？又清空一次？
}
} else {
$whosonlinestatus = 0;//如果后台设置不显示在线人数，则不显示在线列表
}
} else {//对应第77行，如果是分区显示，如url为：index.php?gid=2，则调用下面这个文件，
require_once DISCUZ_ROOT.\'./include/category.inc.php\';
}
include template(\'discuz\');//解析首页的模板文件
[Discuz!] (C)2001-2007 Comsenz Inc.
This is NOT a freeware, use is subject to license terms
$Id: index.php 13764 2008-05-19 03:14:01Z heyond $
*/
define(\'CURSCRIPT\', \'index\');//定义当前运行脚本名
require_once \'./include/common.inc.php\';//引入common文件
require_once DISCUZ_ROOT.\'./include/forum.func.php\';//引入版块处理函数forum.func.php
$discuz_action = 1;//?
if($cacheindexlife && !$discuz_uid && $showoldetails != \'yes\' && (!$_DCACHE[\'settings\'][\'frameon\'] || $_DCACHE[\'settings\'][\'frameon\'] && $_GET[\'frameon\'] != \'yes\') && emptyempty($gid)) {
//分析：$cacheindexlife-首页缓存有效期，$discuz_uid存在，$showoldetails-显示在线详情，$_DCACHE[\'settings\'][\'frameon\']-左右分栏模式开关，$gid-版块组id，自己看看吧，大概就是判断是否使用一个静态htm页面的条件，这个由后台是否开启首页缓存时间来决定的
$indexcache = getcacheinfo(0);//得到首页缓存，此函数见include/forum.func.php 157行，主要是处理index.htm
//下面一段就是判断是否过期咯，如果过期，就删除index.htm，否则读取文件，并根据系统配置决定是否显示debug信息
if($timestamp - $indexcache[\'filemtime\'] > $cacheindexlife) {
@unlink($indexcache[\'filename\']);
define(\'CACHE_FILE\', $indexcache[\'filename\']);
$styleid = $_DCACHE[\'settings\'][\'styleid\'];
} elseif($indexcache[\'filename\']) {
@readfile($indexcache[\'filename\']);
$debug && debuginfo();
$debug ? die(\'<mce:script type="text/javascript"><!--
document.getElementById("debuginfo").innerHTML = " \'.($debug ? \'Updated at \'.gmdate("H:i:s", $indexcache[\'filemtime\'] + 3600 * 8).\', Processed in \'.$debuginfo[\'time\'].\' second(s), \'.$debuginfo[\'queries\'].\' Queries\'.($gzipcompress ? \', Gzip enabled\' : \'\') : \'\').\'";
// --></mce:script>\') : die();
}
}
//$validdays?用户组有效时间？
$validdays = $discuz_uid && !emptyempty($groupexpiry) && $groupexpiry >= $timestamp ? ceil(($groupexpiry - $timestamp) / 86400) : 0;
//是否显示在线情况
if(isset($showoldetails)) {
switch($showoldetails) {
case \'no\': dsetcookie(\'onlineindex\', 0, 86400 * 365); break;
case \'yes\': dsetcookie(\'onlineindex\', 1, 86400 * 365); break;
}
} else {
$showoldetails = false;
}
$currenttime = gmdate($timeformat, $timestamp + $timeoffset * 3600);//当前时间
$lastvisittime = gmdate("$dateformat $timeformat", $lastvisit + $timeoffset * 3600);//上次访问时间
$memberenc = rawurlencode($lastmember);//最后注册用户-对URL进行了编码
$newthreads = round(($timestamp - $lastvisit + 600) / 1000) * 1000;//这个变量不知道干啥的？
$rsshead = $rssstatus ? (\'<link rel="alternate" type="application/rss+xml" title="\'.$bbname.\'" href="\'.$boardurl.\'rss.php?auth=\'.$rssauth." mce_href="\'.$boardurl.\'rss.php?auth=\'.$rssauth."\" />\n") : \'\';//rss的链接
$customtopics = \'\';
if($qihoo[\'maxtopics\']) {
foreach(explode("\t", isset($_DCOOKIE[\'customkw\']) ? $_DCOOKIE[\'customkw\'] : \'\') as $topic) {
$topic = dhtmlspecialchars(trim(stripslashes($topic)));
$customtopics .= \'<a href="topic.php?keyword=\'.rawurlencode($topic).\'" mce_href="topic.php?keyword=\'.rawurlencode($topic).\'" target="_blank">\'.$topic.\'</a> \';
}
}//以上两段，qihoo专题？-后台的扩展-qihoo搜索那里可以设置
$hottagstatus = $tagstatus && $hottags && $_DCACHE[\'tags\'];//显示热门标签
$catlist = $forumlist = $sublist = $forumname = $collapseimg = $collapse = array();//初始化区、版块、子版等数组
$threads = $posts = $todayposts = $fids = $announcepm = 0;//初始化帖子、回复、今日回复、版块id等数组
$postdata = $historyposts ? explode("\t", $historyposts) : array();//历史发帖？
foreach(array(\'forumlinks\', \'birthdays\') as $key) {//处理友情链接与生日用户的显示
if(!isset($_COOKIE[\'discuz_collapse\']) || strpos($_COOKIE[\'discuz_collapse\'], $key) === FALSE) {
$collapseimg[$key] = \'collapsed_no.gif\';
$collapse[$key] = \'\';
} else {
$collapseimg[$key] = \'collapsed_yes.gif\';
$collapse[$key] = \'display: none\';
}
}
$gid = !emptyempty($gid) ? intval($gid) : 0;//区显示方式
if(!$gid) {//如果不是区显示方式，即默认的显示所有版块的首页
$announcements = \'\';//此句与下面一段是处理论坛公告
if($_DCACHE[\'announcements\']) {
$readapmids = !emptyempty($_DCOOKIE[\'readapmid\']) ? explode(\'D\', $_DCOOKIE[\'readapmid\']) : array();
foreach($_DCACHE[\'announcements\'] as $announcement) {
if(emptyempty($announcement[\'groups\']) || in_array($groupid, $announcement[\'groups\'])) {
if(emptyempty($announcement[\'type\'])) {
$announcements .= \'<li><a href="announcement.php?id=\'.$announcement[\'id\'].\'" mce_href="announcement.php?id=\'.$announcement[\'id\'].\'">\'.$announcement[\'subject\'].
\'<i>(\'.gmdate($dateformat, $announcement[\'starttime\'] + $timeoffset * 3600).\')</i></a></li>\';
} elseif($announcement[\'type\'] == 1) {
$announcements .= \'<li><a href="\'.$announcement[\'message\'].\'" mce_href="\'.$announcement[\'message\'].\'" target="_blank">\'.$announcement[\'subject\'].
\'<i>(\'.gmdate($dateformat, $announcement[\'starttime\'] + $timeoffset * 3600).\')</i></a></li>\';
}
}
}
}
unset($_DCACHE[\'announcements\']);//得到公告的字符串后，及时清空这个公告数组
//选出论坛列表的sql，注意这里判断了是否有访问限制，如果$accessmasks不为空，则根据某用户的特殊访问规则选出了 a.allowview这个字段等
$sql = !emptyempty($accessmasks) ?
"SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect, a.allowview FROM {$tablepre}forums f
LEFT JOIN {$tablepre}forumfields ff ON ff.fid=f.fid
LEFT JOIN {$tablepre}access a ON a.uid=\'$discuz_uid\' AND a.fid=f.fid
WHERE f.status>0 ORDER BY f.type, f.displayorder"
: "SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect FROM {$tablepre}forums f
LEFT JOIN {$tablepre}forumfields ff USING(fid)
WHERE f.status>0 ORDER BY f.type, f.displayorder";
$query = $db->query($sql);
while($forum = $db->fetch_array($query)) {//从这里开始得到两个重要数组$catlist $forumlist，保存区信息与版块列表信息
$forumname[$forum[\'fid\']] = strip_tags($forum[\'name\']);//去掉html与php标记，并存入$forumname数组，以fid为键
if($forum[\'type\'] != \'group\') {//如果是普通版块(如type=forum或forum=sub)而不是分区
$threads += $forum[\'threads\'];//主题总数
$posts += $forum[\'posts\'];//帖子总数(主题与回复)
$todayposts += $forum[\'todayposts\'];//今日帖子
if($forum[\'type\'] == \'forum\') {//非最终子版(即type不等于sub和group)的版块
if(forum($forum)) {//forum函数来自include/forum.func.php，处理版块，得到比如版主啊图标啊什么的
$catlist[$forum[\'fup\']][\'forums\'][] = $forum[\'fid\'];//分区数组$catlist更新
$forum[\'orderid\'] = $catlist[$forum[\'fup\']][\'forumscount\']++;//得到版块的排序，所在分区的版块总数加1，每得到一个子版，就自增1
$forum[\'subforums\'] = \'\';//将子版字符串设置为空的，这里不是很明白，forum函数里得到了一个相同名的字符串，这里为何要清空？
$forumlist[$forum[\'fid\']] = $forum;//将$forum数组赋值给$forumlist的一个元素
}
} elseif(isset($forumlist[$forum[\'fup\']])) {//如果此版块的父版块id在$forumlist中存在(由上面的if中得到)，则
$forumlist[$forum[\'fup\']][\'threads\'] += $forum[\'threads\'];
$forumlist[$forum[\'fup\']][\'posts\'] += $forum[\'posts\'];
$forumlist[$forum[\'fup\']][\'todayposts\'] += $forum[\'todayposts\'];//累加三个值
if($subforumsindex && $forumlist[$forum[\'fup\']][\'permission\'] == 2 && !($forumlist[$forum[\'fup\']][\'simple\'] & 16) || ($forumlist[$forum[\'fup\']][\'simple\'] & 8)) {
$forumlist[$forum[\'fup\']][\'subforums\'] .= \'<a href="forumdisplay.php?fid=\'.$forum[\'fid\'].\'" mce_href="forumdisplay.php?fid=\'.$forum[\'fid\'].\'">\'.$forum[\'name\'].\'</a> \';
}//对版块的子版字符串进行处理
}
} else {//否则，如果是分区
if(!isset($_COOKIE[\'discuz_collapse\']) || strpos($_COOKIE[\'discuz_collapse\'], \'category_\'.$forum[\'fid\']) === FALSE) {
$forum[\'collapseimg\'] = \'collapsed_no.gif\';
$collapse[\'category_\'.$forum[\'fid\']] = \'\';
} else {
$forum[\'collapseimg\'] = \'collapsed_yes.gif\';
$collapse[\'category_\'.$forum[\'fid\']] = \'display: none\';
}//上面是对分区开启关闭按钮的处理？
if($forum[\'moderators\']) {
$forum[\'moderators\'] = moddisplay($forum[\'moderators\'], \'flat\');
}//区版主
$forum[\'forumscount\'] = 0;
$catlist[$forum[\'fid\']] = $forum;//更新区版块数组
}
}
foreach($catlist as $catid => $category) {//对分区的显示进行处理，如表格宽度，是否横排版块等等
if($catlist[$catid][\'forumscount\'] && $category[\'forumcolumns\']) {
$catlist[$catid][\'forumcolwidth\'] = floor(100 / $category[\'forumcolumns\']).\'%\';
$catlist[$catid][\'endrows\'] = \'\';
if($colspan = $category[\'forumscount\'] % $category[\'forumcolumns\']) {
while(($category[\'forumcolumns\'] - $colspan) > 0) {
$catlist[$catid][\'endrows\'] .= \'<td> </td>\';
$colspan ++;
}
$catlist[$catid][\'endrows\'] .= \'</tr>\';
}
} elseif(emptyempty($category[\'forumscount\'])) {
unset($catlist[$catid]);
}
}
unset($catid, $category);
if(isset($catlist[0]) && $catlist[0][\'forumscount\']) {//0表示比分区更大一级的一个“虚拟分区”(暂时这么理解，因为有时候url中有fid=0这样的出现)
$catlist[0][\'fid\'] = 0;
$catlist[0][\'type\'] = \'group\';
$catlist[0][\'name\'] = $bbname;
$catlist[0][\'collapseimg\'] = \'collapsed_no.gif\';
} else {
unset($catlist[0]);
}
if($whosonlinestatus == 1 || $whosonlinestatus == 3) {//显示在线情况
$whosonlinestatus = 1;
$onlineinfo = explode("\t", $onlinerecord);//$onlineinfo变量,$onlinerecord来自index.php的extract($_DCACHE)处理
if(emptyempty($_DCOOKIE[\'onlineusernum\'])) {
$onlinenum = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions");//在线人数
if($onlinenum > $onlineinfo[0]) {//如果当前数据库中取得的在线人数大于原来在线人数，则更新$onlinerecord
$_DCACHE[\'settings\'][\'onlinerecord\'] = $onlinerecord = "$onlinenum\t$timestamp";
$db->query("UPDATE {$tablepre}settings SET value=\'$onlinerecord\' WHERE variable=\'onlinerecord\'");//同时更新settings表
require_once DISCUZ_ROOT.\'./include/cache.func.php\';
updatesettings();//更新settings缓存
$onlineinfo = array($onlinenum, $timestamp);//更新$onlineinfo数组
}
dsetcookie(\'onlineusernum\', intval($onlinenum), 300);//将在线人数写入cookie
} else {
$onlinenum = intval($_DCOOKIE[\'onlineusernum\']);//如果cookie中在线人数不为空，直接读出
}
$onlineinfo[1] = gmdate($dateformat, $onlineinfo[1] + ($timeoffset * 3600));//更新在线情况的时间戳
$detailstatus = $showoldetails == \'yes\' || (((!isset($_DCOOKIE[\'onlineindex\']) && !$whosonline_contract) || $_DCOOKIE[\'onlineindex\']) && $onlinenum < 500 && !$showoldetails);//判断在线详情变量，这里比较复杂，仔细看一下，主要是$showoldetails == \'yes\'与cookie中的首页显示啊 一些条件
if($detailstatus) {//以下是处理在线人数列表的
@include language(\'actions\');//引用语言文件 /templates/default/actions.lang.php
$discuz_uid && updatesession();//更新session
$membercount = $invisiblecount = 0;//初始化会员数量及隐身的数量
$whosonline = array();//初始化数组
$maxonlinelist = $maxonlinelist ? $maxonlinelist : 500;//最大在线人数，如果未设置，初始化为500
$query = $db->query("SELECT uid, username, groupid, invisible, action, lastactivity, fid FROM {$tablepre}sessions ".(isset($_DCACHE[\'onlinelist\'][7]) ? \'\' : \'WHERE uid <> 0\')." ORDER BY uid DESC LIMIT ".$maxonlinelist);
while($online = $db->fetch_array($query)) {
if($online[\'uid\']) {//会员
$membercount ++;//会员总数
if($online[\'invisible\']) {//隐身用户
$invisiblecount++;
continue;
} else {
$online[\'icon\'] = isset($_DCACHE[\'onlinelist\'][$online[\'groupid\']]) ? $_DCACHE[\'onlinelist\'][$online[\'groupid\']] : $_DCACHE[\'onlinelist\'][0];//用户组的图标
}
} else {//游客，区别是数据表session里，其uid为0
$online[\'icon\'] = $_DCACHE[\'onlinelist\'][7];
$online[\'username\'] = $_DCACHE[\'onlinelist\'][\'guest\'];
}
$online[\'fid\'] = $online[\'fid\'] ? $forumname[$online[\'fid\']] : 0;//用户正浏览版块？
$online[\'action\'] = $actioncode[$online[\'action\']];//用户正进行的动作
$online[\'lastactivity\'] = gmdate($timeformat, $online[\'lastactivity\'] + ($timeoffset * 3600));//用户上次访问？
$whosonline[] = $online;//赋值给$whosonline数组
}
unset($actioncode, $online);//清空两个变量
if($onlinenum > $maxonlinelist) {//如果总在线人数大于最大在线人数(系统默认为500)，分别取出已登录用户和隐身用户
$membercount = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions WHERE uid <> \'0\'");
$invisiblecount = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions WHERE invisible = \'1\'");
}
if($onlinenum < $membercount) {//如果总在线人数小于在线会员数，则更新cookie中的在线用户人数，注意是onlineusernum而不是onlinenum
$onlinenum = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions");
dsetcookie(\'onlineusernum\', intval($onlinenum), 300);
}
//总结：这里有些混乱，比如总在线人数，在线会员等等，因为变量类似，很容易看错理解错误，多看几遍吧。。。
$guestcount = $onlinenum - $membercount;
$db->free_result($query);//释放数据库连接
unset($online);//清空，230行不是有么？又清空一次？
}
} else {
$whosonlinestatus = 0;//如果后台设置不显示在线人数，则不显示在线列表
}
} else {//对应第77行，如果是分区显示，如url为：index.php?gid=2，则调用下面这个文件，
require_once DISCUZ_ROOT.\'./include/category.inc.php\';
}
include template(\'discuz\');//解析首页的模板文件