diff --git a/util/log.go b/util/log.go
index 38838044..d155a57b 100644
--- a/util/log.go
+++ b/util/log.go
@@ -19,6 +19,7 @@ type Format struct {
 }
 
 //	2009/01/23 01:23:23 d.go:23: message
+// same like log.SetFlags(log.LstdFlags | log.Lshortfile)
 func (*Format) Format(e *log.Entry) ([]byte, error) {
 	return []byte(
 		fmt.Sprintf("%s %s:%d: %s\n",