diff --git a/man2/send.2 b/man2/send.2 index 52f292ecb..5437e32e6 100644 --- a/man2/send.2 +++ b/man2/send.2 @@ -239,10 +239,9 @@ data. .SS sendmsg() The definition of the .I msghdr -structure follows. -See -.BR recv (2) -and below for an exact description of its fields. +structure employed by +.BR sendmsg () +is as follows: .in +4n .nf @@ -253,11 +252,28 @@ struct msghdr { size_t msg_iovlen; /* # elements in msg_iov */ void *msg_control; /* ancillary data, see below */ size_t msg_controllen; /* ancillary data buffer len */ - int msg_flags; /* flags on received message */ + int msg_flags; /* flags (unused) */ }; .fi .in .PP +The +.I msg_name +field is used on an unconnected socket to specify the target +address for a datagram. +It points to a buffer containing the address; the +.I msg_name +field should be set to the size of the address. +For a connected socket, these fields should be specified as NULL and 0, +respectively. + +The +.I msg_iov +and +.I msg_iovlen +fields specify scatter-gather locations, as for +.BR writev (2). + You may send control information using the .I msg_control and @@ -268,10 +284,13 @@ per socket by the value in .IR /proc/sys/net/core/optmem_max ; see .BR socket (7). + +The +.I msg_flags +field is ignored. .\" Still to be documented: .\" Send file descriptors and user credentials using the .\" msg_control* fields. -.\" The flags returned in msg_flags. .SH RETURN VALUE On success, these calls return the number of bytes sent. On error, \-1 is returned, and