send(2N)                                                 send(2N)



     NAME
          send, sendto, sendmsg - send a message from a socket

     SYNOPSIS
          #include <sys/types.h>
          #include <sys/socket.h>

          int send(s, msg, len, flags)
          int s;
          char *msg;
          int len, flags;

          int sendto(s, msg, len, flags, to, tolen)
          int s;
          char *msg;
          int len, flags;
          struct sockaddr *to;
          int tolen;

          int sendmsg(s, msg, flags)
          int s;
          struct msghdr msg[];
          int flags;

     DESCRIPTION
          send, sendto, and sendmsg are used to transmit a message to
          another socket.  send may be used only when the socket is in
          a connected state (i.e., when connect(2N) has been used),
          while sendto and sendmsg may be used at any time.

          The address of the target is given by to with tolen specify-
          ing its size.  The length of the message is given by len.
          If the message is too long to pass atomically through the
          underlying protocol, then the error EMSGSIZE is returned,
          and the message is not transmitted.

          If no message space is available at the socket to hold the
          message to be transmitted, then send normally blocks, unless
          the socket has been placed in nonblocking I/O mode.  The
          select(2N) call may be used to determine when it is possible
          to send more data.

          The flags parameter may be set to MSG_OOB to send ``out-of-
          band'' data on sockets which support this notion (e.g.
          SOCK_STREAM).

          See recv(2N) for a description of the msghdr structure.

     RETURN VALUE
          The call returns the number of characters sent, or -1 if an
          error occurred.




     April, 1990                                                     1

     send(2N)                                                 send(2N)



          No indication of failure to deliver is implicit in a send.
          Return values of -1 indicate some locally detected errors.

     ERRORS
          [EBADF]             An invalid descriptor was specified.

          [ENOTSOCK]          The argument s is not a socket.

          [EFAULT]            An invalid user space address was speci-
                              fied for a parameter.

          [EMSGSIZE]          The socket requires that message be sent
                              atomically, and the size of the message
                              to be sent made this impossible.

          [EWOULDBLOCK]       The socket is marked nonblocking and the
                              requested operation would block.

     SEE ALSO
          connect(2N), recv(2N), socket(2N).



































     2                                                     April, 1990