 a string (see <a href="#History%20Interaction">History Interaction</a>).  Returns:
          <dl>
<dt><code>0</code>
          <dd>If no expansions took place (or, if the only change in
the text was the removal of escape characters preceding the history expansion
character);
<br><dt><code>1</code>
          <dd>if expansions did take place;
<br><dt><code>-1</code>
          <dd>if there was an error in expansion;
<br><dt><code>2</code>
          <dd>if the returned line should be displayed, but not execute