Update to reflect that copy*str() implementations must be able to handle NULL

being passed in the 'done' argument.  Also, s/NULL/NUL/ where appropriate.

share/man/man9/copy.9

@@ -1,4 +1,4 @@
-.\"	$NetBSD: copy.9,v 1.5 1997/11/11 10:06:55 mrg Exp $
+.\"	$NetBSD: copy.9,v 1.6 1998/02/22 17:38:35 kleink Exp $
 .\"
 .\" Copyright (c) 1996 Jason R. Thorpe.
 .\" All rights reserved.
@@ -32,7 +32,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd Jan 7, 1996
+.Dd February 22, 1998
 .Dt COPY 9
 .Os NetBSD
 .Sh NAME
@@ -83,33 +83,42 @@ bytes of data from the kernel-space address
 to the user-space address
 .Fa uaddr .
 .It Fn copystr
-Copies a NULL-terminated string, at most
+Copies a NUL-terminated string, at most
 .Fa len
 bytes long, from kernel-space address
 .Fa kfaddr
 to kernel-space address
 .Fa kdaddr .
-The number of bytes actually copied, including the terminating
-NULL, is returned in
+If the
+.Fa done
+argument is non-NULL,
+the number of bytes actually copied, including the terminating
+NUL, is returned in
 .Fa *done .
 .It Fn copyinstr
-Copies a NULL-terminated string, at most
+Copies a NUL-terminated string, at most
 .Fa len
 bytes long, from user-space address
 .Fa uaddr
 to kernel-space address
 .Fa kaddr .
-The number of bytes actually copied, including the terminating
-NULL, is returned in
+If the
+.Fa done
+argument is non-NULL,
+the number of bytes actually copied, including the terminating
+NUL, is returned in
 .Fa *done .
 .It Fn copyoutstr
-Copies a NULL-terminated string, at most
+Copies a NUL-terminated string, at most
 bytes long, from kernel-space address
 .Fa kaddr
 to user-space address
 .Fa uaddr .
-The number of bytes actually copied, including the terminating
-NULL, is returned in
+If the
+.Fa done
+argument is non-NULL,
+the number of bytes actually copied, including the terminating
+NUL, is returned in
 .Fa *done .
 .El
 .Sh RETURN VALUES