src/pkg/os/types.go | 3 +++

diff --git a/src/pkg/os/types.go b/src/pkg/os/types.go
index dff7090cdbb690e25d83ea4b902c064f920c12be..2638153ddbe1d1fa6ebad5f852d1cbcbdd61a938 100644
--- a/src/pkg/os/types.go
+++ b/src/pkg/os/types.go
@@ -44,6 +44,9 @@ 	ModeSocket                                    // S: Unix domain socket
 	ModeSetuid                                    // u: setuid
 	ModeSetgid                                    // g: setgid
 
+	// Mask for the type bits. For regular files, none will be set.
+	ModeType = ModeDir | ModeSymlink | ModeNamedPipe | ModeSocket | ModeDevice
+
 	ModePerm FileMode = 0777 // permission bits
 )