xnu-6153.121.1.tar.gz

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

diff --git a/bsd/man/man2/sendfile.2 b/bsd/man/man2/sendfile.2
index 8e31581e2378b22ce88b4eb7a0b7418233589189..1e5e537f31cd6c18023b532d2a8e86b40c8ae32a 100644 (file)
--- a/bsd/man/man2/sendfile.2
+++ b/bsd/man/man2/sendfile.2
@@ -66,7 +66,8 @@ argument specifies how many bytes should be sent with 0 having the special
 meaning to send until the end of file has been reached.
 On return the value pointed to by the 
 .Fa len
-argument indicates how many bytes have been sent.
+argument indicates how many bytes have been sent, except when a header or 
+trailer is specified as shown below.
 The 
 .Fa len
 pointer may not be NULL.
@@ -103,6 +104,17 @@ arrays is specified by
 and
 .Fa trl_cnt .
 .Pp
+When a header or trailer is specified, the value of 
+.Fa len
+argument indicates the maximum number of bytes in the header and/or file to be sent.
+It does not control the trailer; if a trailer exists, all of it will be sent.
+If the value of 
+.Fa len
+argument is 0, all of the header and/or file will be sent before the entire trailer is sent.
+On return, the
+.Fa len
+argument specifies the total number of bytes sent.
+.Pp
 The
 .Fa flags
 parameter is reserved for future expansion and must be set to 0. Any other value