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'\" t
.\"     Title: zmq_connect
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
.\"      Date: 10/14/2014
.\"    Manual: 0MQ Manual
.\"    Source: 0MQ 4.0.5
.\"  Language: English
.\"
.TH "ZMQ_CONNECT" "3" "10/14/2014" "0MQ 4\&.0\&.5" "0MQ Manual"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
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.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
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.\" disable hyphenation
.nh
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.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
zmq_connect \- create outgoing connection from socket
.SH "SYNOPSIS"
.sp
\fBint zmq_connect (void \fR\fB\fI*socket\fR\fR\fB, const char \fR\fB\fI*endpoint\fR\fR\fB);\fR
.SH "DESCRIPTION"
.sp
The \fIzmq_connect()\fR function connects the \fIsocket\fR to an \fIendpoint\fR and then accepts incoming connections on that endpoint\&.
.sp
The \fIendpoint\fR is a string consisting of a \fItransport\fR:// followed by an \fIaddress\fR\&. The \fItransport\fR specifies the underlying protocol to use\&. The \fIaddress\fR specifies the transport\-specific address to connect to\&.
.sp
0MQ provides the the following transports:
.PP
\fItcp\fR
.RS 4
unicast transport using TCP, see
\fBzmq_tcp\fR(7)
.RE
.PP
\fIipc\fR
.RS 4
local inter\-process communication transport, see
\fBzmq_ipc\fR(7)
.RE
.PP
\fIinproc\fR
.RS 4
local in\-process (inter\-thread) communication transport, see
\fBzmq_inproc\fR(7)
.RE
.PP
\fIpgm\fR, \fIepgm\fR
.RS 4
reliable multicast transport using PGM, see
\fBzmq_pgm\fR(7)
.RE
.sp
Every 0MQ socket type except \fIZMQ_PAIR\fR supports one\-to\-many and many\-to\-one semantics\&. The precise semantics depend on the socket type and are defined in \fBzmq_socket\fR(3)\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
for most transports and socket types the connection is not performed immediately but as needed by 0MQ\&. Thus a successful call to \fIzmq_connect()\fR 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 \fIserver\fR socket is bound and a \fIclient\fR socket is connected to it does not matter\&. The first exception is when using the inproc:// transport: you must call \fIzmq_bind()\fR before calling \fIzmq_connect()\fR\&. The second exception are \fIZMQ_PAIR\fR sockets, which do not automatically reconnect to endpoints\&.
.sp .5v
.RE
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
following a \fIzmq_connect()\fR, for socket types except for ZMQ_ROUTER, the socket enters its normal \fIready\fR state\&. By contrast, following a \fIzmq_bind()\fR alone, the socket enters a \fImute\fR state in which the socket blocks or drops messages according to the socket type, as defined in \fBzmq_socket\fR(3)\&. A ZMQ_ROUTER socket enters its normal \fIready\fR state for a specific peer only when handshaking is complete for that peer, which may take an arbitrary time\&.
.sp .5v
.RE
.SH "RETURN VALUE"
.sp
The \fIzmq_connect()\fR function returns zero if successful\&. Otherwise it returns \-1 and sets \fIerrno\fR to one of the values defined below\&.
.SH "ERRORS"
.PP
\fBEINVAL\fR
.RS 4
The endpoint supplied is invalid\&.
.RE
.PP
\fBEPROTONOSUPPORT\fR
.RS 4
The requested
\fItransport\fR
protocol is not supported\&.
.RE
.PP
\fBENOCOMPATPROTO\fR
.RS 4
The requested
\fItransport\fR
protocol is not compatible with the socket type\&.
.RE
.PP
\fBETERM\fR
.RS 4
The 0MQ
\fIcontext\fR
associated with the specified
\fIsocket\fR
was terminated\&.
.RE
.PP
\fBENOTSOCK\fR
.RS 4
The provided
\fIsocket\fR
was invalid\&.
.RE
.PP
\fBEMTHREAD\fR
.RS 4
No I/O thread is available to accomplish the task\&.
.RE
.SH "EXAMPLE"
.PP
\fBConnecting a subscriber socket to an in-process and a TCP transport\fR. 
.sp
.if n \{\
.RS 4
.\}
.nf
/* Create a ZMQ_SUB socket */
void *socket = zmq_socket (context, ZMQ_SUB);
assert (socket);
/* Connect it to an in\-process transport with the address \*(Aqmy_publisher\*(Aq */
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);
.fi
.if n \{\
.RE
.\}
.sp
.SH "SEE ALSO"
.sp
\fBzmq_bind\fR(3) \fBzmq_socket\fR(3) \fBzmq\fR(7)
.SH "AUTHORS"
.sp
This page was written by the 0MQ community\&. To make a change please read the 0MQ Contribution Policy at \m[blue]\fBhttp://www\&.zeromq\&.org/docs:contributing\fR\m[]\&.