int sendto(SOCKET                  socket, 
           const char            * buffer, 
           int                     buflen, 
           int                     flags, 
           const struct sockaddr * to, 
           int                     tolen);

Parameters

socket

Socket returned by socket.

buffer

Pointer to data to send.

buflen

Number of bytes to send.

flags

The flags parameter provides options for calls to send. The following options are supported:

Value	Meaning
MSG_QUEUE	the data in buffer is queued in the output window but is not sent; TCP only.

to

Destination address; port number and IP address must be in network byte order. This parameter has type struct sockaddr * for historical reasons. Use type struct sockaddr_in * instead.

tolen

Length of valid information in *to structure.

return value

The number of bytes queued for sending, otherwise SOCKET_ERROR. If an error occurred, call xn_getlasterror and xn_geterror_string to return the error value. Error Codes further describes each error.

Possible values for this function are:

Value	Meaning
EIFACECLOSED	Interface is closed (RTIP-32 specific).
ENETDOWN	Network is down, i.e. send failed; TCP only.
ENETUNREACH	Network unreachable, i.e. keepalive failed; TCP only.
ENOPKTS	Out of DCUs, i.e. packets.
ENOTCONN	Socket is not connected.
ENOTINITIALIZED	RTIP-32 has not been initialized (xn_rtip_init has not been called).
ENOTSOCK	Invalid socket descriptor.
EOPNOTSUPPORT	Socket type not supported for this function.
EOUTPUTFULL	Output list full (RTIP-32 Specific).
ESHUTDOWN	Receives have been disabled by shutdown.
ETIMEDOUT	Operation timed out.
EWOULDBLOCK	Socket is non-blocking but the function would block.

This routine sends n data bytes from buffer to the connection. For TCP, the socket must be connected and the parameters to and tolen are ignored. For UDP, the socket may be connected. Also, if the socket is not bound, the socket will be bound with a unique port number and the local IP address for the interface associated with the IP address sending the data to.

For UDP and RAW (connected or unconnected), the IP address and port number (ignored for RAW) of the destination is in the parameter *to. If sendto is called with INADDR_BROADCAST, the packet is broadcast to all interfaces except loopback.

In order to send to broadcast or multicast addresses, use sendto or connect with remote address set to the broadcast address (INADDR_BROADCAST) or to the multicast address respectfully.

See send for more information.

Left Socket API

Function send

Down Function setsockopt