请教 PHP 如何保留文本中的一段特定代码？

        Dim a%, b%, s$, sok$        Dim HtmlFile As String        HtmlFile = "C:\vb.htm"        sok = ""        Web1.Navigate(HtmlFile)        For Each o In Web1.Document.GetElementsByTagName("div")            If InStr(o.innerHTML, "txtmod") > 0 Then                s = o.innerHTML                a = InStr(o.innerHTML, "txtmod")                b = InStr(o.innerHTML, "subContent")                sok = Mid(s, a - 1, b - a)                sok = Replace(sok, "=txtmod>", "")                sok = Replace(sok, "<SPAN class", "")                Exit For            End If        Next

$s = file_get_contents('t1.html');preg_match('/txtmod(.+?)subContent/is',$s,$m);file_put_contents('t2.html',$m[1]);