os: add ModeType constant to mask file type bits

This covers the lack of IsRegular comfortably:

    if stat.Mode()&os.ModeType == 0 { ... }

R=golang-dev, r, rsc, r, gustavo
CC=golang-dev
https://golang.org/cl/5440075

diff --git a/src/pkg/os/types.go b/src/pkg/os/types.go
index dff7090cdbb690e25d83ea4b902c064f920c12be..2638153ddbe1d1fa6ebad5f852d1cbcbdd61a938 100644 (file)
--- a/src/pkg/os/types.go
+++ b/src/pkg/os/types.go
@@ -44,6 +44,9 @@ const (
        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
 )