re><p>Provides the system ID, basically URL or filename e.g. http://www.sgmlsource.com/dtds/memo.dtd</p>
<div class="variablelist"><table border="0"><col align="left" /><tbody><tr><td><span class="term"><i><tt>ctx</tt></i>:</span></td><td>the user data (XML parser context)</td></tr><tr><td><span class="term"><i><tt>Returns</tt></i>:</span></td><td>a <a href="libxml-xmlstring.html#xmlChar">xmlChar</a> *</td></tr></tbody></table></div><h3><a name="xmlSAX2HasExternalSubset" id="xmlSAX2HasExternalSubset"></a>Fu