an 0, then the search is through
previous entries, otherwise through subsequent entries. 
If <var>string</var> is found, then
the current history index is set to that history entry, and the value
returned is the offset in the line of the entry where
<var>string</var> was found.  Otherwise, nothing is changed, and a -1 is
returned. 
</td></tr>
</table>

<p>
<table width="100%">
<tr>
<td align="left">int <b>history_search_prefix</b><i> </i>(<i>const char *string, int direction</i>)<i>
     </i></td>
<td align