--- Net2/sys/mman.h	2018/04/24 18:03:58	1.1.1.1
+++ Net2/sys/mman.h	2018/04/24 18:16:49	1.1.1.2
@@ -30,9 +30,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)mman.h	7.5 (Berkeley) 6/27/91
+ *	from: @(#)mman.h	7.5 (Berkeley) 6/27/91
+ *	mman.h,v 1.3 1993/05/20 16:22:41 cgd Exp
  */
 
+#ifndef _SYS_MMAN_H_
+#define _SYS_MMAN_H_
+
 /*
  * Protections are chosen from these bits, or-ed together
  */
@@ -85,3 +89,5 @@ int	msync __P((caddr_t, int));
 __END_DECLS
 
 #endif /* !KERNEL */
+
+#endif /* !_SYS_MMAN_H_ */