tags. */ $buf = preg_replace("/
/","/","/","]]>",$buf);
	$buf = preg_replace("//","/","]]>",$buf);
	
	/* Convert tabs to spaces */
	$buf = preg_replace("/\t/","    ",$buf);
	
	/* 
		 is a placeholder, to be replaced by nothing.
		I use it to fool the regexps above when I want a something to
		NOT be replaced (like a literal  tag in a text section, for example).
	*/
	$buf = preg_replace("//","",$buf);

	/* write processed output file */	
	$fo = fopen($xml_out,"w");
	fwrite($fo, $buf);
	fclose($fo);
}
function serve_xml_to_html($xml_file) {
	global $xslt_file;
	
	/* a little sanity checking first */
	if(strlen($xml_file) < 5 or (substr($xml_file,strlen($xml_file)-4,4) != ".xml")) {
		echo "ERROR - Bad filename for xml_file: $xml_file";
		return;
	}
	if(!file_exists($xml_file)) {
		echo "ERROR - no such file: $xml_file";
		return;
	}
	/* get output directory name */
	$outdir = dirname($xml_file);
	/* get base name so I can add .html, etc. */
	$name = basename($xml_file,".xml");
	/* temporary name for processed XML file */
	$xml_p_file = $outdir."/".$name.".xml.p";
	/* name for resulting HTML file */
	$html_file = $outdir.'/'.$name.".html";
	
	/* does html_file need to be regenerated?
		
	   yes if:
	      1. It doesn't exist.
		  2. XML source file is newer than HTML file.
		  3. XSLT template is newer than HTML file.
	*/
	if (!is_file($html_file) or
		(filemtime($xml_file) > filemtime($html_file)) or 
		(filemtime($xslt_file) > filemtime($html_file)) ) {

			/* do CDATA escaping on  tags */
			add_cdata_to_code($xml_file, $xml_p_file);

			/* perform XSLT processing */
			$xslt = xslt_create();
			$res = xslt_process($xslt, $xml_p_file, $xslt_file, $html_file);
			
			/* remove temp file */
			unlink($xml_p_file);

			/* check for errors in XSLT processing */			
			if( !$res ) {
				$s = "ERROR processing $xml_file with $xslt_file
";
				$s .= "XSLT Error: ".xslt_errno($xslt).": ".xslt_error($xslt);
				xslt_free($xslt);
				echo $s;
				return;
			}
			xslt_free($xslt);
		}
	
	/* serve html file */
	readfile($html_file);
}
?>