DirSize takes a path and returns its size in bytes.

EvalSymlinksAlways behaves like filepath.EvalSymlinks but does not require that all path components must exist.

GetDeviceInfo returns the type, major, and minor numbers of a device.

IsDeviceNode checks if the given path points to a block or char device.

IsExecutable checks if the given path points to an executable file by checking the executable bit.

Returns a nil slice and nil error if the xattr is not set.

TODO(sgotti) waiting for a utimensat functions accepting flags and a LUtimesNano using it in https://github.com/golang/sys/.

TODO(sgotti) use UTIMES_OMIT on linux if Time.IsZero ?.