Function nix::sys::socket::sendmsg

pub fn sendmsg(
    fd: RawFd, 
    iov: &[IoVec<&[u8]>], 
    cmsgs: &[ControlMessage<'_>], 
    flags: MsgFlags, 
    addr: Option<&SockAddr>
) -> Result<usize>

Send data in scatter-gather vectors to a socket, possibly accompanied by ancillary data. Optionally direct the message at the given address, as with sendto.

Allocates if cmsgs is nonempty.