ull(CINTTYPE, (char *) &amp;i);

</pre><p>
       </p></dd><dt id="ECPG-INFORMIX-FUNCTIONS-RISNULL"><span class="term"><code class="function">risnull</code></span> <a href="#ECPG-INFORMIX-FUNCTIONS-RISNULL" class="id_link">#</a></dt><dd><p>
        Test if a variable is NULL.
</p><pre class="synopsis">
int risnull(int t, char *ptr);
</pre><p>
        The function receives the type of the variable to test (<code class="literal">t</code>)
        as well a pointer to this variable (<code class="literal">ptr</