Sendmsg contd

• Msghdr structure:

  • scatter/gather array structure, avoids additional memory copying.
  • send control information using the msg_control and msg_controllen members.

• struct msghdr {

• void * msg_name; /*optional address*/

• socklen_t msg_namelen; /*size of address*/

• struct iovec * msg_iov; /*scatter/gather array*/

• size_t msg_iovlen; /*# elements in msg_iov*/

• void * msg_control; /*ancillary data, see below*/

• socklen_t msg_controllen; /*ancillary data buffer len*/

• int msg_flags; /*flags on received message*/

• };