 Event Callback Procedure</a></span></dt><dt><span class="sect2"><a href="libpq-events.html#LIBPQ-EVENTS-FUNCS">34.14.3. Event Support Functions</a></span></dt><dt><span class="sect2"><a href="libpq-events.html#LIBPQ-EVENTS-EXAMPLE">34.14.4. Event Example</a></span></dt></dl></dd><dt><span class="sect1"><a href="libpq-envars.html">34.15. Environment Variables</a></span></dt><dt><span class="sect1"><a href="libpq-pgpass.html">34.16. The Password File</a></span></dt><dt><span class="sect1"><a href="libpq-pgse