a #GSocketAddress, or %NULL
an array of #GOutputVector structs
a pointer to an array of #GSocketControlMessages, or %NULL.
an int containing #GSocketMsgFlags flags
a %GCancellable or %NULL
Number of bytes written (which may be less than @size), or -1 on error
GException on failure.
2.22
Send data to @address on @socket. For sending multiple messages see g_socket_send_messages(); for easier use, see g_socket_send() and g_socket_send_to().
If @address is %NULL then the message is sent to the default receiver (set by g_socket_connect()).
@vectors must point to an array of #GOutputVector structs and @num_vectors must be the length of this array. (If @num_vectors is -1, then @vectors is assumed to be terminated by a #GOutputVector with a %NULL buffer pointer.) The #GOutputVector structs describe the buffers that the sent data will be gathered from. Using multiple #GOutputVectors is more memory-efficient than manually copying data from multiple sources into a single buffer, and more network-efficient than making multiple calls to g_socket_send().
@messages, if non-%NULL, is taken to point to an array of @num_messages #GSocketControlMessage instances. These correspond to the control messages to be sent on the socket. If @num_messages is -1 then @messages is treated as a %NULL-terminated array.
@flags modify how the message is sent. The commonly available arguments for this are available in the #GSocketMsgFlags enum, but the values there are the same as the system values, and the flags are passed in as-is, so you can pass in system-specific flags too.
If the socket is in blocking mode the call will block until there is space for the data in the socket queue. If there is no space available and the socket is in non-blocking mode a %G_IO_ERROR_WOULD_BLOCK error will be returned. To be notified when space is available, wait for the %G_IO_OUT condition. Note though that you may still receive %G_IO_ERROR_WOULD_BLOCK from g_socket_send() even if you were previously notified of a %G_IO_OUT condition. (On Windows in particular, this is very common due to the way the underlying APIs work.)
On error -1 is returned and @error is set accordingly.