zmq_connect(3)

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.

ØMQ provides the the following transports:

-tcp -: -
-unicast transport using TCP, see zmq_tcp(7) -
-
-ipc -: -
-local inter-process communication transport, see zmq_ipc(7) -
-
-inproc -: -
-local in-process (inter-thread) communication transport, see zmq_inproc(7) -
-
-pgm, epgm -: -
-reliable multicast transport using PGM, see zmq_pgm(7) -
-

Every ØMQ 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(3).

- - - -

Note

for most transports and socket types the connection is not performed -immediately but as needed by ØMQ. 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(3). 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 ØMQ 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

Connecting a subscriber socket to an in-process and a TCP transport

/* 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);

AUTHORS

This page was written by the ØMQ community. To make a change please -read the ØMQ Contribution Policy at http://www.zeromq.org/docs:contributing.

-zmq_connect(3) Manual Page -

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