用正则表达式取出table中的所有行（支持嵌套table）

表达式:
<tr[^>]*>(?:(?:\s|\S)*?(?=<table|</tr>)(?(<table)<table[^>]*>(?:\s|\S)*?(?:</table>|(?:(?:<table[^>]*>(?:\s|\S)*?</table>(?:\s|\S)*?)*?</table>))(?:\s|\S)*?|))*</tr>

一条表达式就可以获取你想要的
写得好辛苦
测试:

<table width="300" border="1" cellspacing="0" cellpadding="0">
  <tr>
    <td>&nbsp;</td>
    <td><table width="100%" border="1" cellspacing="0" cellpadding="0">
      <tr>
        <td>&nbsp;</td>
        </tr>

    </table>
      <table width="100%" border="1" cellspacing="0" cellpadding="0">
        <tr>
          <td>&nbsp;</td>
        </tr>
      </table></td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td><table width="100%" border="1" cellspacing="0" cellpadding="0">

      <tr>
        <td>&nbsp;</td>
        </tr>
    </table></td>
  </tr>
  <tr>
    <td><table width="100%" border="1" cellspacing="0" cellpadding="0">
      <tr>
        <td>&nbsp;</td>
        </tr>

    </table></td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
</table>

-------------------获取3个match
============================================match1
  <tr>
    <td>&nbsp;</td>
    <td><table width="100%" border="1" cellspacing="0" cellpadding="0">
      <tr>
        <td>&nbsp;</td>
        </tr>

    </table>
      <table width="100%" border="1" cellspacing="0" cellpadding="0">
        <tr>
          <td>&nbsp;</td>
        </tr>
      </table></td>
    <td>&nbsp;</td>
  </tr>
==============================================match2
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td><table width="100%" border="1" cellspacing="0" cellpadding="0">

      <tr>
        <td>&nbsp;</td>
        </tr>
    </table></td>
  </tr>
==============================================match3
  <tr>
    <td><table width="100%" border="1" cellspacing="0" cellpadding="0">
      <tr>
        <td>&nbsp;</td>
        </tr>

    </table></td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>

http://www.cnblogs.com/xioxu/archive/2006/12/27/604843.html