tart at offset start_offset WARNING: in contrast to strstr(), this one does not stop at the first \0 in the pbuf/source string!</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramname">p</td><td>pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as return value 'not found' </td></tr>
    <tr><td class="paramname">substr</td><td>string to search for in p, maximum length is 0xFFFE </td></tr>
  </table>
  </dd>
</dl>
<dl class="section return"><dt>Returns