recv(2)                        DG/UX 5.4R3.00                        recv(2)


NAME
       recv - receive a message from a socket

SYNOPSIS
       #include <sys/socket.h>

       int  recv (s, buf, len, userflags)
       int  s;
       void * buf;
       int  len;
       int  userflags;

   where:
       s              File descriptor of socket to receive data from

       buf            Buffer for data

       len            Length of buffer for data (bytes)

       userflags     Flags for transfer

DESCRIPTION
       This call can be used only with connected sockets.

       If the message is too long to fit in the supplied buffer, excess
       bytes may be discarded depending on the type of socket the message is
       received from; datagram sockets truncate messages, stream sockets
       don't preserve packet boundaries so only the amount of data requested
       is received with no loss of data.

       The userflags argument is constructed by or-ing zero or more
       literals beginning with "MSG_".  See <sys/socket.h> for a description
       of what flags exist and what they do.

       If no messages are available at the socket, the call waits for a
       message to arrive, unless the socket is nonblocking [see ioctl(2)].
       In that case, an error EAGAIN will be returned.

       The select call may be used to determine when more data arrives.

ACCESS CONTROL
       None.

RETURN VALUE
       Recv returns the number of bytes received.

       0..len    Number of bytes transferred.

       -1        An error occurred.  errno is set to indicate the error.

DIAGNOSTICS
       Errno may be set to one of the following error codes:

       EBADF          The argument s is not an active valid descriptor.



Licensed material--property of copyright holder(s)                         1

recv(2)                        DG/UX 5.4R3.00                        recv(2)


       ENOTSOCK       The argument s is not a socket.

       EAGAIN         The socket is marked non-blocking and the receive
                      operation would block.

       EINTR          The receive was interrupted by delivery of a signal
                      before any data was available for the receive.

       EFAULT         The data was specified to be received into a non-
                      existent or protected part of the process address
                      space.

       EINVAL         Invalid argument.

       ENOTCONN       The socket is not connected.  Use recvfrom(2).

       EOPNOTSUPP     The flags argument included the MSG_OOB flag applied
                      to a UDP socket.

SEE ALSO
       ioctl(2), read(2), recvfrom(2), select(2), send(2), socket(2).




































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