(PHP 5 >= 5.0.4)
XSLTProcessor::hasExsltSupport — Determine if PHP has EXSLT support
如果成功则返回 TRUE，失败则返回 FALSE。
Example #1 Testing EXSLT support
<?php
$proc = new XSLTProcessor;
if (!$proc->hasExsltSupport()) {
die('EXSLT support not available');
}
// do EXSLT stuff here ..
?>