discuz的PHP分页函数

function multi($num, $perpage, $curpage, $mpurl) {
$multipage = '';
$mpurl .= strpos($mpurl, '?') ? '&' : '?';
if($num > $perpage) {
$page = 10;
$offset = 5;
$pages = @ceil($num / $perpage);
if($page > $pages) {
$from = 1;
$to = $pages;
} else {
$from = $curpage - $offset;
$to = $curpage + $page - $offset - 1;
if($from < 1) {
$to = $curpage + 1 - $from;
$from = 1;
if(($to - $from) < $page && ($to - $from) < $pages) {
$to = $page;
}
} elseif($to > $pages) {
$from = $curpage - $pages + $to;
$to = $pages;
if(($to - $from) < $page && ($to - $from) < $pages) {
$from = $pages - $page + 1;
}
}
}
$multipage = ($curpage - $offset > 1 && $pages > $page ? '<a href="'.$mpurl.'page=1" mce_href="'.$mpurl.'page=1">第一页</a> ' : '').($curpage > 1 ? '<a href="'.$mpurl.'page='.($curpage - 1).'" mce_href="'.$mpurl.'page='.($curpage - 1).'">上一页</a> ' : '');
for($i = $from; $i <= $to; $i++) {
$multipage .= $i == $curpage ? $i.' ' : '<a href="'.$mpurl.'page='.$i.'" mce_href="'.$mpurl.'page='.$i.'">['.$i.']</a> ';
}
$multipage .= ($curpage < $pages ? '<a href="'.$mpurl.'page='.($curpage + 1).'" mce_href="'.$mpurl.'page='.($curpage + 1).'">下一页<