Sockets Library Functions                           send(3SOCKET)

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

SYNOPSIS
     cc [ flag ... ] file ... -lsocket  -lnsl [ library ... ]
     #include <sys/types.h>
     #include <sys/socket.h>

     ssize_t send(int s, const void *msg, size_t len, int flags);

     ssize_t sendto(int s,  const  void  *msg,  size_t  len,  int
     flags, const struct sockaddr *to, int  tolen);

     ssize_t sendmsg(int s, const struct msghdr *msg, int flags);

DESCRIPTION
     send(), sendto(), and sendmsg() are used to transmit a  mes-
     sage to another transport end-point. send() may be used only
     when the socket is in a connected state, while sendto()  and
     sendmsg()  may  be  used  at any time. s is a socket created
     with socket(3SOCKET).

     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.

     A return value of -1 indicates locally detected errors only.
     It does not implicitly mean the message was not delivered.

     If the socket does not have enough buffer space available to
     hold  the  message  being  sent,  send()  blocks, unless the
     socket  has  been  placed  in  non-blocking  I/O  mode  (see
     fcntl(2)).  The  select(3C)  or  poll(2) call may be used to
     determine when it is possible to send more data.

     The flags parameter is formed from the bitwise OR of zero or
     more of the following:

     MSG_OOB
           Send "out-of-band" data on sockets that  support  this
           notion.   The  underlying  protocol  must also support
           "out-of-band" data. Only SOCK_STREAM  sockets  created
           in  the  AF_INETand  AF_INET  address families support
           out-of-band data.

     MSG_DONTROUTE
           The SO_DONTROUTE option is turned on for the  duration
           of  the  operation.  It  is used only by diagnostic or
           routing programs.

SunOS 5.8            Last change: 8 Nov 1999                    1

Sockets Library Functions                           send(3SOCKET)

     See recv(3SOCKET) for a description of the msghdr structure.

RETURN VALUES
     These calls return the number of bytes sent,  or  -1  if  an
     error occurred.

ERRORS
     The calls fail if:

     EBADF s is an invalid file descriptor.

     EINTR The operation was interrupted by delivery of a  signal
           before any data could be buffered to be sent.

     EINVAL
           tolen is not the size  of  a  valid  address  for  the
           specified address family.

     EMSGSIZE
           The socket requires that message be  sent  atomically,
           and the message was too long.

     ENOMEM
           There was insufficient memory  available  to  complete
           the operation.

     ENOSR There were insufficient  STREAMS  resources  available
           for the operation to complete.

     ENOTSOCK
           s is not a socket.

     EWOULDBLOCK
           The socket is marked non-blocking  and  the  requested
           operation would block.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | Safe                        |
    |_____________________________|_____________________________|

SEE ALSO
     fcntl(2),     poll(2),      write(2),      connect(3SOCKET),
     getsockopt(3SOCKET),        recv(3SOCKET),       select(3C),
     socket(3SOCKET), attributes(5), socket(3HEAD)

SunOS 5.8            Last change: 8 Nov 1999                    2