code>). Note that the
        latter needs to be cast to a char*. See the function <a class="xref" href="ecpg-informix-compat.html#RSETNULL"><code class="function">rsetnull</code></a> for a list of possible variable types.
       </p><p>
        Here is an example of how to use this function:
</p><pre class="programlisting">
$char c[] = "abc       ";
$short s = 17;
$int i = -74874;

risnull(CCHARTYPE, (char *) c);
risnull(CSHORTTYPE, (char *) &amp;s);
risnull(CINTTYPE, (char *) &amp;i);

</pre><p>
       </