src/os/example_test.go | 1 +

diff --git a/src/os/example_test.go b/src/os/example_test.go
index 5c96ebb417dcd258e842fed36fa113e1318c821e..8b6566e1496edceb36bfcca6269cd0e999e33fe5 100644
--- a/src/os/example_test.go
+++ b/src/os/example_test.go
@@ -55,6 +55,7 @@ 	if err != nil {
 		log.Fatal(err)
 	}
 
+	fmt.Printf("permissions: %#o\n", fi.Mode().Perm()) // 0400, 0777, etc.
 	switch mode := fi.Mode(); {
 	case mode.IsRegular():
 		fmt.Println("regular file")