``NULL is a specific instance of a null pointer constant; the generic is

a "null pointer".''

Making good use of the excellent explanations sent to me by Ruslan
Ermilov, Garrett Wollman and Bruce Evans, correct the descriptions of
null pointers.  They are just "null pointers", not nil, not NULL or
".Dv NULL".

Suggested by:	ru, wollman, bde
Reviewed by:	ru, wollman
Pointy hat:	keramida

1 files changed, 4 insertions, 11 deletions

diff --git a/lib/libc/sys/select.2 b/lib/libc/sys/select.2
index 193c903..d90d521 100644
--- a/lib/libc/sys/select.2
+++ b/lib/libc/sys/select.2
@@ -108,23 +108,18 @@ to the maximum number of descriptors supported by the system.
 .Pp
 If
 .Fa timeout
-is not a
-.Dv NULL
-pointer, it specifies the maximum interval to wait for the
+is not a null pointer, it specifies the maximum interval to wait for the
 selection to complete.
 System activity can lengthen the interval by
 an indeterminate amount.
 .Pp
 If
 .Fa timeout
-is a
-.Dv NULL
-pointer, the select blocks indefinitely.
+is a null pointer, the select blocks indefinitely.
 .Pp
 To effect a poll, the
 .Fa timeout
-argument should not be
-.Dv NULL ,
+argument should not be a null pointer,
 but it should point to a zero-valued timeval structure.
 .Pp
 Any of
@@ -132,9 +127,7 @@ Any of
 .Fa writefds ,
 and
 .Fa exceptfds
-may be given as
-.Dv NULL
-pointers if no descriptors are of interest.
+may be given as null pointers if no descriptors are of interest.
 .Sh RETURN VALUES
 The
 .Fn select