sendmsg

 

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 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
 
 
 

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