php discuz核心类函数分析_PHP教程

<?php 

/**
* [Discuz!] (C)2001-2099 Comsenz Inc.
* This is NOT a freeware, use is subject to license terms
*
* $Id: class_core.php 6914 2010-03-26 12:52:36Z cnteacher $
*/ 

///TODO 是将要完成的功能，包括禁止ip和禁止访问 
//TODO 禁止ip 
//TODO 禁止访问 

///和DZ72一样，确保所有文件需要先加载核心文件 
define('IN_DISCUZ', true); 

/**
* Discuz 核心引擎
* 其他处理代码当中用到的变量不要在本核心 new 之前设置， 否则会自动清空
*
*/ 
class discuz_core { 

// 数据库存储引擎 
var $db = null; 

// 内存缓冲object 
var $mem = null; 

// 会话 object 
var $session = null; 

// 程序配置 
var $config = array(); 

// $_G 数组的映射 
var $var = array(); 

// 加载缓存的数组 
var $cachelist = array(); 

// 是否初始化 
var $init_setting = true; //设置 
var $init_user = true;//用户 
var $init_session = true;//会话 
var $init_cron = true;//任务计划 
var $init_misc = true;//其他功能 
var $init_memory = true;//内存 

// 是否已经初始化 
var $initated = false; 

var $superglobal = array( 
'GLOBALS' => 1, 
'_GET' = 1, 
'_POST' = 1, 
'_REQUEST' = 1, 
'_COOKIE' = 1, 
'_SERVER' = 1, 
'_ENV' = 1, 
'_FILES' = 1, 
); 

function &instance() { 
static $object; 
if(empty($object)) { 
$object = new discuz_core(); 
} 
return $object; 
} 

function discuz_core() { 
$this->_init_env(); 
$this->_init_config(); 
$this->_init_input(); 
$this->_init_output(); 
} 

function init() { 
if(!$this->initated) { 
$this->_init_db(); 
$this->_init_memory(); 
$this->_init_user(); 
$this->_init_session(); 
$this->_init_setting(); 
$this->_init_cron(); 
$this->_init_misc(); 
} 
$this->initated = true; 
} 

function _init_env() { 

error_reporting(E_ALL ^ E_NOTICE); 
// error_reporting(E_ALL); 
///php 5.3前则关闭魔法引号匹配(自动转义) 
if(phpversion() < '5.3.0') { 
set_magic_quotes_runtime(0); 
} 

///程序主目录，根据核心文件确定，原来是-7 代表在include下,现在是12代表在source/class下 
define('DISCUZ_ROOT', substr(dirname(__FILE__), 0, -12)); 
///和dz72一样，设置魔法引用(自动转义，单双引号反斜线) 
define('MAGIC_QUOTES_GPC', function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc()); 
///判断字符编码转换函数是否存在 
define('ICONV_ENABLE', function_exists('iconv')); 
///亚洲字符转码函数是否存在, 因为mb_开头字符处理亚洲字符会比较高效，初步判断用于转码时先用mb_来处理: 
define('MB_ENABLE', function_exists('mb_convert_encoding')); 
///是否存在输出缓存压缩函数，这个函数的目的，是在确认浏览器支持页面压缩后，才用该函数来压缩所有输出内容，否则直接传输 
define('EXT_OBGZIP', function_exists('ob_gzhandler')); 

///和DZ72一样，不过当前时间戳被定义为一个常量，效率更高吧，也不用global了。 
define('TIMESTAMP', time()); 
///获取默认时区 
discuz_core::timezone_set(); 

///加载function_core.php，作用推测类似global.func.php 
if(!defined('DISCUZ_CORE_FUNCTION') && !@include(DISCUZ_ROOT.'./source/function/function_core.php')) { 
$this->error('function_core.php is missing'); 
} 

//判断浏览器是否是蜘蛛 
define('IS_ROBOT', checkrobot()); 

//清理全局变量 
///全清理了，真是彻底把所有变量都从内存中注销了 
foreach ($GLOBALS as $key = $value) { 
if (!isset($this->superglobal[$key])) { 
$GLOBALS[$key] = null; unset($GLOBALS[$key]); 
} 
} 

// 配置全局变量 
///和上一步结合，只留下自己需要的变量，并初始化。 
///这么做够狠，只要稍微小心点，就不会出现因为变量未初始化而出现的安全问题 
global $_G; 
$_G = array( 
//公用全局定义 
'uid' = 0, 
'username' = '', 
'adminid' = 0, 
'groupid' = 1, 
'sid' = '', 
'formhash' = '', 
'timestamp' = TIMESTAMP, 
'starttime' = dmicrotime(), 
'clientip' = $this->_get_client_ip(), 
'referer' = '', 
'charset' = '', 
'gzipcompress' = '', 
'authkey' = '', 
'timenow' = array(), 

'PHP_SELF' = '', 
'siteurl' = '', 

//公用全局数组定义 
'config' = array(), 
'setting' = array(), 
'member' = array(), 
'group' = array(), 
'cookie' = array(), 
'style' = array(), 
'cache' = array(), 
'session' = array(), 
'lang' = array(), 
'my_app' = array(),//默认应用 
'my_userapp' = array(),//用户自添加应用 

//论坛全局定义 
'fid' = 0, 
'tid' = 0, 
'forum' = array(), 
'rssauth' = '', 

//uch 全局定义 
'home' = array(), 
'space' = array(), 

//portal 全局定义 
'block' = array(), 
'article' = array(), 

//Action 
'action' = array( 
'action' = APPTYPEID, 
'fid' = 0, 
'tid' = 0, 
) 
); 
//相对主目录的相对地址及文件名 
$_G['PHP_SELF'] = htmlspecialchars($_SERVER['PHP_SELF'] ? $_SERVER['PHP_SELF'] : $_SERVER['SCRIPT_NAME']); 
//基本脚本名，每个功能脚本首页前都会定义 
//比如forum.php，则定义CURSCRIPT为forum,而forum_forumdisplay.php则不定义，因为属于forum 
$_G['basescript'] = CURSCRIPT; 
//站点网址 
$_G['siteurl'] = htmlspecialchars('http://'.$_SERVER['HTTP_HOST'].preg_replace("/\/+(api)?\/*$/i", '', substr($_G['PHP_SELF'], 0, strrpos($_G['PHP_SELF'], '/'))).'/'); 

///$_G的映射，也即超级全局变量 
$this->var = & $_G; 

} 

function _init_input() { 

//note 禁止对全局变量注入 
///和dz72类似，禁止GLOBALS=xxx的方式注入 
if (isset($_REQUEST['GLOBALS']) || isset($_FILES['GLOBALS'])) { 
error('request_tainting'); 
} 

if(!empty($_GET['rewrite'])) { 
$query_string = '?mod='; 
$param = explode('-', $_GET['rewrite']); 
$query_string .= $_GET['mod'] = $param[0]; 
array_shift($param); 
$paramc = count($param); 
for($i = 0;$i < $paramc;$i+=2) { 
$_REQUEST[$param[$i]] = $_GET[$param[$i]] = $param[$i + 1]; 
$query_string .= '&'.$param[$i].'='.$param[$i + 1]; 
} 
$_SERVER['QUERY_STRING'] = $query_string; 
unset($param, $paramc, $query_string); 
} 

// slashes 处理,如果没有魔法引号处理（自动转义），则手动转义GET/POST/COOKIE/FILES中的单双引号、null反斜线\ 
if(!MAGIC_QUOTES_GPC) { 
$_GET = daddslashes($_GET); 
$_POST = daddslashes($_POST); 
$_COOKIE = daddslashes($_COOKIE); 
$_FILES = daddslashes($_FILES); 
} 

//cookie 处理 
///验证cookie前缀与config中的设置值是否一致，一致则转为$cookie数组中的值 
$prelength = strlen($this->config['cookie']['cookiepre']); 
foreach($_COOKIE as $key = $val) { 
if(substr($key, 0, $prelength) == $this->config['cookie']['cookiepre']) { 
$this->var['cookie'][substr($key, $prelength)] = $val; 
} 
} 

$_GET['diy'] = empty($_GET['diy']) ? '' : $_GET['diy']; 

///$_GET和$_POST转成与索引同名加"gp_"前缀的变量 
///如$_GET['username']直接用$gp_username来访问 
foreach(array_merge($_POST, $_GET) as $k = $v) { 
$this->var['gp_'.$k] = $v; 
} 

///根据$_GET['mod']来确定m的值，$this->var为全局数组,gp_为上个语句的附加前缀 
$this->var['mod'] = empty($this->var['gp_mod']) ? '' : htmlspecialchars($this->var['gp_mod']); 
///如果使用ajax，再判断是post传值或get和xmlhttprequest同时有效 
$this->var['inajax'] = empty($this->var['gp_inajax']) ? 0 : ($_SERVER['REQUEST_METHOD'] == 'GET' && $_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest' || $_SERVER['REQUEST_METHOD'] == 'POST' ? 1 : 0); 
///当前页码 
$this->var['page'] = empty($this->var['gp_page']) ? 1 : max(1, intval($this->var['gp_page'])); 
///确定cookie中的sid值 
$this->var['sid'] = $this->var['cookie']['sid'] = isset($this->var['cookie']['sid']) ? htmlspecialchars($this->var['cookie']['sid']) : ''; 
} 

///初始化设置 
function _init_config() { 
///加载设置文件 
$_config = array(); 
@include DISCUZ_ROOT.'./config/config_global.php'; 
if(empty($_config)) { 
error('config_notfound'); 
} 
///确定密钥，如果值为空，则密钥默认为cookie前缀与数据库名拼接的md5值，否则为配置文件中的值 
///authkey密钥是sid等参数加解密的重要参数 
$_config['security']['authkey'] = empty($config['security']['authkey']) ? md5($_config['cookie']['cookiepre'].$_config['db'][1]['dbname']) : ($config['security']['authkey']); 

$this->config = & $_config; 
///Discuz的调试 
if(empty($this->config['debug']) || !file_exists(libfile('function/debug'))) { 
define('DISCUZ_DEBUG', false); 
} elseif($this->config['debug'] === 1 || $this->config['debug'] === 2 || !empty($_REQUEST['debug']) && $_REQUEST['debug'] === $this->config['debug']) { 
define('DISCUZ_DEBUG', true); 
if($this->config['debug'] == 2) { 
error_reporting(E_ALL); 
} 
} 

$GLOBALS['_G']['config'] = & $this->config; 
///以浏览器版本为参考，进行密钥的二次md5加密 
$GLOBALS['_G']['authkey'] = md5($this->config['security']['authkey'].$_SERVER['HTTP_USER_AGENT']); 
} 

function _init_output() { 
///如果设置中打开xss跨站脚本的防御模式，且网址中存在"<"和"""等非法字符，则拒绝请求 
if($this->config['security']['urlxssdefend'] && !empty($_SERVER['REQUEST_URI'])) { 
$temp = urldecode($_SERVER['REQUEST_URI']); 
if(strpos($temp, '<') !== false || strpos($temp, '"') !== false) { 
error('request_tainting'); 
} 
} 

///存在ob_gzhandler则启用输出缓存压缩 
if($this->config['output']['gzip'] && EXT_OBGZIP) { 
ob_start('ob_gzhandler'); 
setglobal('gzipcompress', true); 
} else { 
ob_start(); 
setglobal('gzipcompress', false); 
} 

///确定HTML页面编码，及其他编码 
if($this->config['output']['forceheader']) { 
@header('Content-Type: text/html; charset='.$this->config['output']['charset']); 
} 

setglobal('charset', $this->config['output']['charset']); 
define('CHARSET', $this->config['output']['charset']); 
} 

///拒绝机器人访问 
function reject_robot() { 
if(IS_ROBOT) { 
exit(header("HTTP/1.1 403 Forbidden")); 
} 
} 

///获取客户端ip， 
function _get_client_ip() { 
$clientip = ''; 
///环境变量客户端ip有值且字符长度大于unknown，则说明该变量有效，确定为客户端ip 
if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) { 
$clientip = getenv('HTTP_CLIENT_IP'); 
///否则取当前浏览用户的网关ip地址 
} elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) { 
$clientip = getenv('HTTP_X_FORWARDED_FOR'); 
///用户计算机的ip地址 
} elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) { 
$clientip = getenv('REMOTE_ADDR'); 
} elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) { 
$clientip = $_SERVER['REMOTE_ADDR']; 
} 

///判断是否是数字与点组成的7-15位字符 
preg_match("/[\d\.]{7,15}/", $clientip, $clientipmatches); 
$clientip = $clientipmatches[0] ? $clientipmatches[0] : 'unknown'; 
return $clientip; 
} 

function _init_db() { 
///生成数据库对象 
$this->db = & DB::object(); 
///加载设置文件并连接数据库 
$this->db->set_config($this->config['db']); 
$this->db->connect(); 
} 

function _init_session() { 

$this->session = new discuz_session(); 

if($this->init_session) 
{ 
///传入sid，客户端ip与uid作为session判断机制，分新老用户，老用户则查session表，否则创建 
$this->session->init($this->var['cookie']['sid'], $this->var['clientip'], $this->var['uid']); 
$this->var['sid'] = $this->session->sid; 
$this->var['session'] = $this->session->var; 

if($this->var['sid'] != $this->var['cookie']['sid']) { 
dsetcookie('sid', $this->var['sid'], 86400); 
} 

// 首次登陆更新最后访问时间，每隔 10 分钟更新用户最后动作时间 
if($this->var['uid'] && ($this->session->isnew || ($this->session->get('lastactivity') + 600) < TIMESTAMP)) { 

$this->session->set('lastactivity', TIMESTAMP); 

$update = array('lastip' = $this->var['clientip'], 'lastactivity' = TIMESTAMP); 
if($this->session->isnew) { 
$update['lastvisit'] = TIMESTAMP; 
} 
更新会员状态 
DB::update('common_member_status', $update, "uid='".$this->var['uid']."'"); 
} 
} 
} 

function _init_user() { 

if($this->init_user) { 
if($auth = getglobal('auth', 'cookie')) { 
$auth = daddslashes(explode("\t", authcode($auth, 'DECODE'))); 
} 
list($discuz_pw, $discuz_uid) = empty($auth) || count($auth) < 2 ? array('', '') : $auth; 

if($discuz_uid) { 
$user = getuserbyuid($discuz_uid); 
} 

if(!empty($user) && $user['password'] == $discuz_pw) { 
$this->var['member'] = $user; 
} else { 
$user = array(); 
$this->_init_guest(); 
} 

$this->cachelist[] = 'usergroup_'.$this->var['member']['groupid']; 
if($user && $user['adminid'] 0 && $user['groupid'] != $user['adminid']) { 
$this->cachelist[] = 'admingroup_'.$this->var['member']['adminid']; 
} 

} else { 
$this->_init_guest(); 
} 

if(empty($this->var['cookie']['lastvisit'])) { 
$this->var['member']['lastvisit'] = TIMESTAMP - 3600; 
dsetcookie('lastvisit', TIMESTAMP - 3600, 86400 * 30); 
} else { 
$this->var['member']['lastvisit'] = empty($this->var['cookie']['lastvisit']); 
} 

setglobal('uid', getglobal('uid', 'member')); 
setglobal('username', addslashes(getglobal('username', 'member'))); 
setglobal('adminid', getglobal('adminid', 'member')); 
setglobal('groupid', getglobal('groupid', 'member')); 
} 

function _init_guest() { 
setglobal('member', array( 'uid' = 0, 'username' = '', 'groupid' = 7, 'credits' = 0, 'timeoffset' = 9999)); 
} 

function _init_cron() { 
if($this->init_cron && $this->init_setting) { 
if($this->var['cache']['cronnextrun'] <= TIMESTAMP) { 
discuz_cron::run(); 
} 
} 
} 

function _init_misc() { 

if(!$this->init_misc) { 
return false; 
} 
// 调入核心语言包 
lang('core'); 

//处理全局时区设置 
if($this->init_setting && $this->init_user) { 
if(!isset($this->var['member']['timeoffset']) || $this->var['member']['timeoffset'] == 9999 || $this->var['member']['timeoffset'] === '') { 
$this->var['member']['timeoffset'] = $this->var['setting']['timeoffset']; 
} 
} 

$timeoffset = $this->init_setting ? $this->var['member']['timeoffset'] : $this->var['setting']['timeoffset']; 
$this->var['timenow'] = array( 
'time' = dgmdate(TIMESTAMP), 
'offset' = $timeoffset = 0 ? ($timeoffset == 0 ? '' : '+'.$timeoffset) : $timeoffset 
); 
$this->timezone_set($timeoffset); 

$this->var['formhash'] = formhash(); 
define('FORMHASH', $this->var['formhash']); 

// 定义风格常量 
if(is_array($this->var['style'])) { 
foreach ($this->var['style'] as $key = $val) { 
$key = strtoupper($key); 
if(!defined($key) && !is_array($val)) { 
define($key, $val); 
} 
} 
} 

//论坛开关检查 
if($this->var['setting']['**losed'] && !(in_array($this->var['mod'], array('logging', 'seccode')) || getglobal('adminid', 'member') == 1)) { 
$closedreason = DB::result_first("SELECT svalue FROM ".DB::table('common_setting')." WHERE skey='closedreason'"); 
showmessage($closedreason ? $closedreason : 'board_closed', NULL, array(), array('login' = 1)); 
} 

$this->var['tpp'] = $this->var['setting']['topicperpage'] ? intval($this->var['setting']['topicperpage']) : 20; 
$this->var['ppp'] = $this->var['setting']['postperpage'] ? intval($this->var['setting']['postperpage']) : 10; 

if($this->var['setting']['nocacheheaders']) { 
@header("Expires: -1"); 
@header("Cache-Control: no-store, private, post-check=0, pre-check=0, max-age=0", FALSE); 
@header("Pragma: no-cache"); 
} 

$lastact = TIMESTAMP."\t".htmlspecialchars(basename($this->var['PHP_SELF']))."\t".htmlspecialchars($this->var['mod']); 
dsetcookie('lastact', $lastact, 86400); 

} 

function _init_setting() { 

if($this->init_setting) { 

if(empty($this->var['setting'])) { 
$this->cachelist[] = 'setting'; 
} 

if(empty($this->var['style'])) { 
$this->cachelist[] = 'style_default'; 
} 

if(!isset($this->var['cache']['cronnextrun'])) { 
$this->cachelist[] = 'cronnextrun'; 
} 
} 

!empty($this->cachelist) && loadcache($this->cachelist); 

if(!is_array($this->var['setting'])) { 
$this->var['setting'] = array(); 
} 
if($this->var['member'] && $this->var['member']['adminid'] 0 && $this->var['member']['groupid'] != $this->var['member']['adminid'] && !empty($this->var['cache']['admingroup_'.$this->var['member']['adminid']])) { 
$this->var['group'] = array_merge($this->var['group'], $this->var['cache']['admingroup_'.$this->var['member']['adminid']]); 
} 
} 

function _init_memory() { 
$this->mem = new discuz_memory(); 
if($this->init_memory) { 
$this->mem->init($this->config['memory']); 
} 
$this->var['memory'] = $this->mem->type; 
} 

function timezone_set($timeoffset = 0) { 
if(function_exists('date_default_timezone_set')) { 
@date_default_timezone_set('Etc/GMT'.($timeoffset 0 ? '-' : '+').(abs($timeoffset))); 
} 
} 

function error($msg, $halt = true) { 
$this->error_log($msg); 
echo $msg; 
$halt && exit(); 
} 

function error_log($message) { 
$time = date("Y-m-d H:i:s", TIMESTAMP); 
$file = DISCUZ_ROOT.'./data/log/errorlog_'.date("Ym").'.txt'; 
$message = "\n#{$time}:\t".str_replace(array("\t", "\r", "\n"), " ", $message); 
error_log($message, 3, $file); 
} 

} 

/** 
* Discuz MySQL 类的支持 
* 
*/ 
class db_mysql 
{ 
var $tablepre; 
var $version = ''; 
var $querynum = 0; 
var $curlink; 
var $link = array(); 
var $config = array(); 
var $sqldebug = array(); 

function db_mysql($config = array()) { 
if(!empty($config)) { 
$this->set_config($config); 
} 
} 

function set_config($config) { 
$this->config = &$config; 
$this->tablepre = $config['1']['tablepre']; 
} 

function connect() { 

if(empty($this->config) || empty($this->config[1])) { 
$this->halt('notfound_config'); 
} 

foreach ($this->config as $id = $config) { 
$this->link[$id] = $this->_dbconnect( 
$config['dbhost'], 
$config['dbuser'], 
$config['dbpw'], 
$config['dbcharset'], 
$config['dbname'], 
$config['pconnect'] 
); 
} 
$this->curlink = $this->link[1]; 
} 

function _dbconnect($dbhost, $dbuser, $dbpw, $dbcharset, $dbname, $pconnect) { 
$link = null; 
$func = empty($pconnect) ? 'mysql_connect' : 'mysql_pconnect'; 
if(!$link = @$func($dbhost, $dbuser, $dbpw, 1)) { 
$this->halt('notconnect'); 
} else { 
$this->curlink = $link; 
if($this->version() '4.1') { 
$serverset = $dbcharset ? 'character_set_connection='.$dbcharset.', character_set_results='.$dbcharset.', character_set_client=binary' : ''; 
$serverset .= $this->version() '5.0.1' ? ((empty($serverset) ? '' : ',').'sql_mode=\'\'') : ''; 
$serverset && mysql_query("SET $serverset", $link); 
} 
$dbname && @mysql_select_db($dbname, $link); 
} 
return $link; 
} 

function table_name($tablename) { 
return $this->tablepre.$tablename; 
} 

function select_db($dbname) { 
return mysql_select_db($dbname, $this->curlink); 
} 

function fetch_array($query, $result_type = MYSQL_ASSOC) { 
return mysql_fetch_array($query, $result_type); 
} 

function fetch_first($sql) { 
return $this->fetch_array($this->query($sql)); 
} 

function result_first($sql) { 
return $this->result($this->query($sql), 0); 
} 

function query($sql, $type = '') { 

if(defined('DISCUZ_DEBUG') && DISCUZ_DEBUG) { 
$starttime = dmicrotime(); 
} 
$func = $type == 'UNBUFFERED' && @function_exists('mysql_unbuffered_query') ? 
'mysql_unbuffered_query' : 'mysql_query'; 
if(!($query = $func($sql, $this->curlink))) { 
if(in_array($this->errno(), array(2006, 2013)) && substr($type, 0, 5) != 'RETRY') { 
$this->connect(); 
return $this->query($sql, 'RETRY'.$type); 
} 
if($type != 'SILENT' && substr($type, 5) != 'SILENT') { 
$this->halt('query_error', $sql); 
} 
} 

if(defined('DISCUZ_DEBUG') && DISCUZ_DEBUG) { 
$this->sqldebug[] = array($sql, number_format((dmicrotime() - $starttime), 6), debug_backtrace()); 
} 

$this->querynum++; 
return $query; 
} 

function affected_rows() { 
return mysql_affected_rows($this->curlink); 
} 

function error() { 
return (($this->curlink) ? mysql_error($this->curlink) : mysql_error()); 
} 

function errno() { 
return intval(($this->curlink) ? mysql_errno($this->curlink) : mysql_errno()); 
} 

function result($query, $row = 0) { 
$query = @mysql_result($query, $row); 
return $query; 
} 

function num_rows($query) { 
$query = mysql_num_rows($query); 
return $query; 
} 

function num_fields($query) { 
return mysql_num_fields($query); 
} 

function free_result($query) { 
return mysql_free_result($query); 
} 

function insert_id() { 
return ($id = mysql_insert_id($this->curlink)) = 0 ? $id : $this->result($this->query("SELECT last_insert_id()"), 0); 
} 

function fetch_row($query) { 
$query = mysql_fetch_row($query); 
return $query; 
} 

function fetch_fields($query) { 
return mysql_fetch_field($query); 
} 

function version() { 
if(empty($this->version)) { 
$this->version = mysql_get_server_info($this->curlink); 
} 
return $this->version; 
} 

function close() { 
return mysql_close($this->curlink); 
} 

function halt($message = '', $sql = '') { 
global $_G; 
$dberror = $this->error(); 
$dberrno = $this->errno(); 
$phperror = '<table style="font-size:11px" cellpadding="0"><tr><td width="270">File</td><td width="80">Line</td><td>Function</td></tr>'; 
foreach (debug_backtrace() as $error) { 
$error['file'] = str_replace(DISCUZ_ROOT, '', $error['file']); 
$error['class'] = isset($error['class']) ? $error['class'] : ''; 
$error['type'] = isset($error['type']) ? $error['type'] : ''; 
$error['function'] = isset($error['function']) ? $error['function'] : ''; 
$phperror .= "<tr><td>$error[file]</td><td>$error[line]</td><td>$error[class]$error[type]$error[function]()</td></tr>"; 
} 
$phperror .= '</table>'; 
$helplink = "http://faq.comsenz.com/?type=mysql&dberrno=".rawurlencode($dberrno)."&dberror=".rawurlencode($dberror); 
@header('Content-Type: text/html; charset='.$_G['config']['output']['charset']); 
echo '<p style="position:absolute;font-size:11px;font-family:verdana,arial;background:#EBEBEB;padding:0.5em;line-height:1.5em">'. 
error('db_error', array( 
'$message' = error('db_'.$message, array(), true), 
'$info' = $dberror ? error('db_error_message', array('$dberror' = $dberror), true) : '', 
'$sql' = $sql ? error('db_error_sql', array('$sql' = $sql), true) : '', 
'$errorno' = $dberrno ? error('db_error_no', array('$dberrno' = $dberrno), true) : '', 
'$helplink' = $helplink, 
), true); 
echo "<b>PHP Backtrace</b><br />$phperror<br /></p>"; 
exit(); 
} 

} 

/**
* 对Discuz CORE 中 DB Object中的主要方法进行二次封装，方便程序调用
*
*/ 
class DB 
{ 

/**
* 返回表名(pre_$table)
*
* @param 原始表名 $table
* @return 增加pre之后的名字
*/ 
function table($table) { 
$a = & DB::object(); 
return $a->table_name($table); 
} 

/**
* 删除一条或者多条记录
*
* @param string $table 原始表名
* @pa