zmq_msg_init(3) [debian man page]

ZMQ_MSG_INIT(3) 						    0MQ Manual							   ZMQ_MSG_INIT(3)

NAME

       zmq_msg_init - initialise empty 0MQ message

SYNOPSIS

       int zmq_msg_init (zmq_msg_t *msg);

DESCRIPTION

       The zmq_msg_init() function shall initialise the message object referenced by msg to represent an empty message. This function is most
       useful when called before receiving a message with zmq_recv().

	   Caution
	   Never access zmq_msg_t members directly, instead always use the zmq_msg family of functions.

	   Caution
	   The functions zmq_msg_init(), zmq_msg_init_data() and zmq_msg_init_size() are mutually exclusive. Never initialize the same zmq_msg_t
	   twice.

RETURN VALUE

       The zmq_msg_init() function shall return zero if successful. Otherwise it shall return -1 and set errno to one of the values defined below.

ERRORS

       No errors are defined.

EXAMPLE

       Receiving a message from a socket.

	   zmq_msg_t msg;
	   rc = zmq_msg_init (&msg);
	   assert (rc == 0);
	   rc = zmq_recv (socket, &msg, 0);
	   assert (rc == 0);

SEE ALSO

       zmq_msg_init_size(3) zmq_msg_init_data(3) zmq_msg_close(3) zmq_msg_data(3) zmq_msg_size(3) zmq(7)

AUTHORS

       This manual page was written by the 0MQ community.

0MQ 2.2.0							    04/04/2012							   ZMQ_MSG_INIT(3)

ZMQ_MSG_INIT_DATA(3)						    0MQ Manual						      ZMQ_MSG_INIT_DATA(3)

NAME

       zmq_msg_init_data - initialise 0MQ message from a supplied buffer

SYNOPSIS

       typedef void (zmq_free_fn) (void *data, void *hint);

       int zmq_msg_init_data (zmq_msg_t *msg, void *data, size_t size, zmq_free_fn *ffn, void *hint);

DESCRIPTION

       The zmq_msg_init_data() function shall initialise the message object referenced by msg to represent the content referenced by the buffer
       located at address data, size bytes long. No copy of data shall be performed and 0MQ shall take ownership of the supplied buffer.

       If provided, the deallocation function ffn shall be called once the data buffer is no longer required by 0MQ, with the data and hint
       arguments supplied to zmq_msg_init_data().

	   Caution
	   Never access zmq_msg_t members directly, instead always use the zmq_msg family of functions.

	   Caution
	   The deallocation function ffn needs to be thread-safe, since it will be called from an arbitrary thread.

	   Caution
	   The functions zmq_msg_init(), zmq_msg_init_data() and zmq_msg_init_size() are mutually exclusive. Never initialize the same zmq_msg_t
	   twice.

RETURN VALUE

       The zmq_msg_init_data() function shall return zero if successful. Otherwise it shall return -1 and set errno to one of the values defined
       below.

ERRORS

       No errors are defined.

EXAMPLE

       Initialising a message from a supplied buffer.

	   void my_free (void *data, void *hint)
	   {
	       free (data);
	   }

	       /*  ...	*/

	   void *data = malloc (6);
	   assert (data);
	   memcpy (data, "ABCDEF", 6);
	   zmq_msg_t msg;
	   rc = zmq_msg_init_data (&msg, data, 6, my_free, NULL);
	   assert (rc == 0);

SEE ALSO

       zmq_msg_init_size(3) zmq_msg_init(3) zmq_msg_close(3) zmq_msg_data(3) zmq_msg_size(3) zmq(7)

AUTHORS

       This manual page was written by the 0MQ community.

0MQ 2.2.0							    04/04/2012						      ZMQ_MSG_INIT_DATA(3)