include标签代码优化，集思广益~~

txt.html
<html>
<body>
<include file="Tpl/top.html">
<div></div>
<include file="Tpl/foot.html">
</body>
</html>$txt=file_get_contents("txt.html");//include替换
        $return = preg_match_all("/<\s*include\s+file=\"(.*)\"\s*>/", $txt, $inc);
        if ($return) {
            $inc1 = $inc[0]; //<include file="top.html">系列数组
            $inc2 = $inc[1]; //top.html 系列数组
            foreach ($inc2 as $v) {
                if (file_exists($v)) {
                    $sub = file_get_contents($v);
                    foreach ($inc1 as $v1) {
                        //区分大小写匹配
                        if (ereg($v, $v1)) {
                            $txt = str_replace($v1, $sub, $txt);
                        }
                    }
                } else {
                    exit("include标签解析出错!");
                }
            }
        }
        echo $txt;
        //--include替换
谁能写出更好的include标签解析代码