additional comments WithExt

client/pkg/fileutil/purge.go

@@ -62,6 +62,7 @@ func purgeFile(lg *zap.Logger, dirname string, suffix string, max uint, interval
 			// fnames is a slice of filename strings
 			// note ReadDir reads files already in sorted order,
 			// so could filter for suffixes and not have to sort again (maybe?)
+			// also ReadDir already has helper WithExt method could use?
 			fnames, err := ReadDir(dirname)
 			if err != nil {
 				errC <- err