Why use fprintf?

fprintf call error because url encoding string have "%".

web/concrete/jobs/generate_sitemap.php

@@ -79,7 +79,7 @@ public function run() {
 			if(!$hFile = @fopen($osName, 'w')) {
 				throw new \Exception(t('Cannot open file %s', $osName));
 			}
-			if(!@fprintf($hFile, $dom->saveXML())) {
+			if(!@fwrite($hFile, $dom->saveXML())) {
 				throw new \Exception(t('Error writing to file %s', $osName));
 			}
 			@fflush($hFile);