zmq_msg_routing_id - Man Page

return routing ID for message, if any


uint32_t zmq_msg_routing_id (zmq_msg_t *message);


The zmq_msg_routing_id() function returns the routing ID for the message, if any. The routing ID is set on all messages received from a ZMQ_SERVER socket. To send a message to a ZMQ_SERVER socket you must set the routing ID of a connected ZMQ_CLIENT peer. Routing IDs are transient.

Return Value

The zmq_msg_routing_id() function shall return zero if there is no routing ID, otherwise it shall return an unsigned 32-bit integer greater than zero.


Receiving a client message and routing ID.

void *ctx = zmq_ctx_new ();
assert (ctx);

void *server = zmq_socket (ctx, ZMQ_SERVER);
assert (server);
int rc = zmq_bind (server, "tcp://");
assert (rc == 0);

zmq_msg_t message;
rc = zmq_msg_init (&message);
assert (rc == 0);

//  Receive a message from socket
rc = zmq_msg_recv (server, &message, 0);
assert (rc != -1);
uint32_t routing_id = zmq_msg_routing_id (&message);
assert (routing_id);

See Also



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Referenced By

zmq_msg_set_routing_id(3), zmq_socket(3).

08/13/2020 0MQ 4.3.3 0MQ Manual