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libzmq/doc/zmq_connect.txt
Pieter Hintjens 67e02ca8bc Use of named authors on man pages is no longer a good idea since it puts off
contributors and doesn't reflect the real process. I've taken out all named
authors and referred to the contribution policy. Hopefully this will improve
the contributions to the man pages.
2013-04-15 18:50:42 +02:00

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zmq_connect(3)
==============
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 linkzmq:zmq_tcp[7]
'ipc':: local inter-process communication transport, see linkzmq:zmq_ipc[7]
'inproc':: local in-process (inter-thread) communication transport, see linkzmq:zmq_inproc[7]
'pgm', 'epgm':: reliable multicast transport using PGM, see linkzmq:zmq_pgm[7]
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
linkzmq:zmq_socket[3].
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
linkzmq: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 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
-------
.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);
----
SEE ALSO
--------
linkzmq:zmq_bind[3]
linkzmq:zmq_socket[3]
linkzmq:zmq[7]
AUTHORS
-------
This page was written by the 0MQ community. To make a change please
read the 0MQ Contribution Policy at <http://www.zeromq.org/docs:contributing>.