getClusterSizeOfCurrentDirectory.go

var (
	modkernel32        = windows.NewLazySystemDLL("kernel32.dll")
	procCreateServiceW = modkernel32.NewProc("GetDiskFreeSpaceW")
)

func getClusterSizeOfCurrentDirectory() (int64, error) {
	var lpSectorsPerCluster, lpBytesPerSector, lpNumberOfFreeClusters, lpTotalNumberOfClusters int64

	//	cstr, _ := syscall.BytePtrFromString("C:")
	_, _, errNo := syscall.Syscall6(procCreateServiceW.Addr(),
		6,
		0,
		uintptr(unsafe.Pointer(&lpSectorsPerCluster)),
		uintptr(unsafe.Pointer(&lpBytesPerSector)),
		uintptr(unsafe.Pointer(&lpNumberOfFreeClusters)),
		uintptr(unsafe.Pointer(&lpTotalNumberOfClusters)),
		0)

	if errNo != 0 {
		return 0, errNo
	}

	return lpSectorsPerCluster * lpBytesPerSector, nil
}