--- Net2/sys/filedesc.h	2018/04/24 18:03:58	1.1
+++ Net2/sys/filedesc.h	2018/04/24 18:16:58	1.1.1.2
@@ -30,9 +30,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)filedesc.h	7.4 (Berkeley) 5/4/91
+ *	from: @(#)filedesc.h	7.4 (Berkeley) 5/4/91
+ *	filedesc.h,v 1.3 1993/05/20 16:22:17 cgd Exp
  */
 
+#ifndef _SYS_FILEDESC_H_
+#define _SYS_FILEDESC_H_
+
 /*
  * This structure is used for the management of descriptors.  It may be
  * shared by multiple processes.
@@ -97,3 +101,5 @@ int	falloc __P((struct proc *p, struct f
 struct	filedesc *fdcopy __P((struct proc *p));
 void	fdfree __P((struct proc *p));
 #endif
+
+#endif /* !_SYS_FILEDESC_H_ */