NAME
zmq_connect - create outgoing connection from socket
SYNOPSIS
int zmq_connect (void *socket, const char *endpoint);
DESCRIPTION
The zmq_connect() function connects the socket to an endpoint and then accepts incoming connections on that endpoint.
The endpoint is a string consisting of a transport://
followed by an
address. The transport specifies the underlying protocol to use. The
address specifies the transport-specific address to connect to.
0MQ provides the the following transports:
- tcp
-
unicast transport using TCP, see zmq_tcp
- ipc
-
local inter-process communication transport, see zmq_ipc
- inproc
-
local in-process (inter-thread) communication transport, see zmq_inproc
- pgm, epgm
-
reliable multicast transport using PGM, see zmq_pgm
Every 0MQ socket type except ZMQ_PAIR supports one-to-many and many-to-one semantics. The precise semantics depend on the socket type and are defined in zmq_socket.
Note
|
for most transports and socket types the connection is not performed immediately but as needed by 0MQ. Thus a successful call to zmq_connect() does not mean that the connection was or could actually be established. Because of this, for most transports and socket types the order in which a server socket is bound and a client socket is connected to it does not matter. The first exception is when using the inproc:// transport: you must call zmq_bind() before calling zmq_connect(). The second exception are ZMQ_PAIR sockets, which do not automatically reconnect to endpoints. |
Note
|
following a zmq_connect(), for socket types except for ZMQ_ROUTER, the socket enters its normal ready state. By contrast, following a zmq_bind() alone, the socket enters a mute state in which the socket blocks or drops messages according to the socket type, as defined in zmq_socket. A ZMQ_ROUTER socket enters its normal ready state for a specific peer only when handshaking is complete for that peer, which may take an arbitrary time. |
RETURN VALUE
The zmq_connect() function returns zero if successful. Otherwise it returns
-1
and sets errno to one of the values defined below.
ERRORS
- EINVAL
-
The endpoint supplied is invalid.
- EPROTONOSUPPORT
-
The requested transport protocol is not supported.
- ENOCOMPATPROTO
-
The requested transport protocol is not compatible with the socket type.
- ETERM
-
The 0MQ context associated with the specified socket was terminated.
- ENOTSOCK
-
The provided socket was invalid.
- EMTHREAD
-
No I/O thread is available to accomplish the task.
EXAMPLE
/* Create a ZMQ_SUB socket */ void *socket = zmq_socket (context, ZMQ_SUB); assert (socket); /* Connect it to an in-process transport with the address 'my_publisher' */ int rc = zmq_connect (socket, "inproc://my_publisher"); assert (rc == 0); /* Connect it to the host server001, port 5555 using a TCP transport */ rc = zmq_connect (socket, "tcp://server001:5555"); assert (rc == 0);
SEE ALSO
AUTHORS
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