感谢网友@popcorner的贡献，此程序为后台搜索索引生成工具，在论坛根目录执行即可

<?php
/**
 *      [Discuz!] (C)2001-2099 Comsenz Inc.
 *      This is NOT a freeware, use is subject to license terms
 */
error_reporting(E_ALL);
$sourcedir = './';
chdir($sourcedir);
define('IN_ADMINCP', TRUE);
define('NOROBOT', TRUE);
define('ADMINSCRIPT', basename(__FILE__));
define('CURSCRIPT', 'admin');
define('APPTYPEID', 0);
include './source/class/class_core.php';
include './source/class/class_admincp.php';
include './source/function/function_misc.php';
include './source/function/function_forum.php';
include './source/function/function_admincp.php';
include './source/function/function_cache.php';
$discuz = & discuz_core::instance();
$discuz->init();
$admincp = new discuz_admincp();
$admincp->core  = & $discuz;
$admincp->init();
$admincpdir = 'source/admincp/';
$langfile = 'source/language/lang_admincp.php';
$menulangfile = 'source/language/lang_admincp_menu.php';
$searchindex = 'source/language/lang_admincp_searchindex.php';
define('IN_DISCUZ', 1);
define('IN_ADMINCP', 1);
include $menulangfile;
$menulang = $lang;
$_G['siteurl'] = '';
include $langfile;
$lang = $lang + $menulang;
$indexdata = array();
include $sourcedir.'function/function_admincp.php';
include $admincpdir.'admincp_menu.php';
foreach($menu as $topmenu => $leftmenu) {
    foreach($leftmenu as $item) {
        if(!isset($item[2]) && isset($menulang[$item[0]])) {
            list($action, $operation, $do) = explode('_', $item[1]);
            $indexdata[] = array('index' => array(
                $menulang[$item[0]] => 'action='.$action.($operation ? '&operation='.$operation.($do ? '&do='.$do : '') : '')
            ), 'text' => array($menulang[$item[0]]));
        }
    }
}
$langi = '|'.implode('|', array_keys($lang)).'|';
$dir = opendir($admincpdir);
while($entry = readdir($dir)) {
    if($entry != '.' && $entry != '..' && preg_match('/^admincp\_/', $entry)) {
        $adminfile = $admincpdir.$entry;        
        $data = file_get_contents($adminfile);
        $data = preg_replace('/\/\/.+?\r/', '', $data);
        $data = preg_replace_callback('/\/\*(.+?)\*\//s', 'clearnote', $data);
        preg_match_all('#/\*search=\s*(\{.+?\})\s*\*/(.+?)/\*search\*/#is', $data, $search);
        if($search) {
            foreach($search[0] as $k => $item) {
                $search[1][$k] = stripslashes($search[1][$k]);
                $titles = json_decode($search[1][$k], 1);
                $titlesnew = $titletext = array();
                foreach($titles as $title => $url) {
                    $titlekey = strip_tags(isset($lang[$title]) ? $lang[$title] : $title);
                    $titlesnew[$titlekey] = $url;
                    if($titlekey[0] != '_') {
                        $titletext[] = $titlekey;
                    }
                }
                $data = $search[2][$k];
                preg_match_all("/(showsetting|showtitle|showtableheader|showtips)\('(\w+)'/", $data, $r);
                if($r[2]) {
                    $l = array();
                    if($titletext) {
                        $l[] = implode(' &raquo; ', $titletext);
                    }
                    $tm = array();
                    foreach($r[2] as $i) {
                        if(in_array($i,$tm)) {
                            continue;
                        }
                        $tm[] = $i;
                        $l[] = strip_tags($i);
                        $l[] = strip_tags($lang[$i]);
                        $preg = '/\|('.preg_quote($i).'_comment)\|/';
                        preg_match_all($preg, $langi, $lr);
                        if($lr[1]) {
                            foreach($lr[1] as $li) {
                                $l[] = strip_tags($lang[$li]);
                            }
                        }
                    }
                    $indexdata[] = array('index' => $titlesnew, 'text' => $l);
                }
            }
        }
    }
}
$return = '<?php
/**
 *      [Discuz!] (C)2001-2099 Comsenz Inc.
 *      This is NOT a freeware, use is subject to license terms
 *
 *      $Id: adminsearchindex2.php 26203 2011-12-05 10:07:49Z monkey $
 *
 *    This file is automatically generate
 */
$lang = '.var_export($indexdata, 1).';
?>';
file_put_contents($searchindex, $return);
echo 'Done!';
function clearnote($s) {
    if(!preg_match('/^search/i', $s[1])) {
        return '';
    } else {
        return '/*'.$s[1].'*/';
    }
}
function unicode_encode($name) {
    $name = iconv('GBK', 'UCS-2', $name);
    $len = strlen($name);
    $str = '';
    for ($i = 0; $i < $len - 1; $i = $i + 2) {
        $c = $name[$i];
        $c2 = $name[$i + 1];
        if (ord($c) > 0) {
            $str .= '\u'.base_convert(ord($c), 10, 16).base_convert(ord($c2), 10, 16);
        } else {
            $str .= $c2;
        }
    }
    return $str;
}