ZMQ_CONNECT

Section: 0MQ Manual (3) Updated: 10/15/2010 Local index Up

NAME

zmq_connect - connect a socket

SYNOPSIS

int zmq_connect (void *socket, const char *endpoint);

DESCRIPTION

The zmq_connect() function shall connect the socket referenced by the socket argument to the endpoint specified by the endpoint argument.

The endpoint argument is a string consisting of two parts as follows: transport://address. The transport part specifies the underlying transport protocol to use. The meaning of the address part is specific to the underlying transport protocol selected.

The following transports are defined:

inproc

: local in-process (inter-thread) communication transport, see zmq_inproc(7)

ipc

: local inter-process communication transport, see zmq_ipc(7)

tcp

: unicast transport using TCP, see zmq_tcp(7)

pgm, epgm

: reliable multicast transport using PGM, see zmq_pgm(7)

With the exception of ZMQ_PAIR sockets, a single socket may be connected to multiple endpoints using zmq_connect(), while simultaneously accepting incoming connections from multiple endpoints bound to the socket using zmq_bind(). Refer to zmq_socket(3) for a description of the exact semantics involved when connecting or binding a socket to multiple endpoints.

Note

The connection will not be performed immediately but as needed by 0MQ. Thus a successful invocation of zmq_connect() does not indicate that a physical connection was or can actually be established.

RETURN VALUE

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

ERRORS

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.

EFAULT

: The provided socket was not valid (NULL).

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);