xnu-7195.50.7.100.1.tar.gz

[apple/xnu.git] / bsd / man / man2 / select.2

diff --git a/bsd/man/man2/select.2 b/bsd/man/man2/select.2
index fd0833dc1f98f27def260c0086ee38253ddde6da..b6b56c03430199baefa493d019663ee91dd76d95 100644 (file)
--- a/bsd/man/man2/select.2
+++ b/bsd/man/man2/select.2
@@ -140,13 +140,19 @@ to the maximum number of descriptors supported by the system.
 .Pp
 If
 .Fa timeout
-is a non-nil pointer, it specifies a maximum interval to wait for the
-selection to complete.  If 
+is not a null pointer, it specifies a maximum interval to wait for the
+selection to complete.
+.Pp
+If
 .Fa timeout
-is a nil pointer, the select blocks indefinitely.  To effect a poll, the
+is a null pointer, the select blocks indefinitely.
+.Pp
+To effect a poll, the
+.Fa timeout
+argument should be not be a null pointer,
+but it should point to a zero-valued timeval structure.
+.Pp
 .Fa timeout
-argument should be non-nil, pointing to a zero-valued timeval structure.
-.Fa Timeout
 is not changed by
 .Fn select ,
 and may be reused on subsequent calls, however it is good style to re-initialize
@@ -158,7 +164,7 @@ Any of
 .Fa writefds ,
 and
 .Fa errorfds
-may be given as nil pointers if no descriptors are of interest.
+may be given as null pointers if no descriptors are of interest.
 .Sh RETURN VALUES
 .Fn select
 returns the number of ready descriptors that are contained in