---
name: "zmq_bind"
section: "3"
platform: "linux"
package: "zeromq"
version: "4.3.5-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/zmq_bind"
---

# zmq\_bind(3)

accept incoming connections on a socket

## NAME

zmq\_bind - accept incoming connections on a socket

## SYNOPSIS

**int zmq\_bind (void** *\*socket***, const char** *\*endpoint***);**

## DESCRIPTION

The *zmq\_bind()* function binds the *socket* to a local *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 bind to.

0MQ provides the the following transports:

*tcp*

unicast transport using TCP, see [**zmq\_tcp**(7)](/zmq_tcp/7.md)

*ipc*

local inter-process communication transport, see [**zmq\_ipc**(7)](/zmq_ipc/7.md)

*inproc*

local in-process (inter-thread) communication transport, see [**zmq\_inproc**(7)](/zmq_inproc/7.md)

*pgm*, *epgm*

reliable multicast transport using PGM, see [**zmq\_pgm**(7)](/zmq_pgm/7.md)

*vmci*

virtual machine communications interface (VMCI), see [**zmq\_vmci**(7)](/zmq_vmci/7.md)

*udp*

unreliable unicast and multicast using UDP, see [**zmq\_udp**(7)](/zmq_udp/7.md)

Every 0MQ socket type except *ZMQ\_PAIR* and *ZMQ\_CHANNEL* supports one-to-many and many-to-one semantics. The precise semantics depend on the socket type and are defined in [**zmq\_socket**(3)](/zmq_socket/3.md).

The *ipc*, *tcp*, *vmci* and *udp* transports accept wildcard addresses: see [**zmq\_ipc**(7)](/zmq_ipc/7.md), [**zmq\_tcp**(7)](/zmq_tcp/7.md), [**zmq\_vmci**(7)](/zmq_vmci/7.md) and [**zmq\_udp**(7)](/zmq_udp/7.md) for details.

**Note**\

the address syntax may be different for *zmq\_bind()* and *zmq\_connect()* especially for the *tcp*, *pgm* and *epgm* transports.

**Note**\

following a *zmq\_bind()*, the socket enters a *mute* state unless or until at least one incoming or outgoing connection is made, at which point the socket enters a *ready* state. In the mute state, the socket blocks or drops messages according to the socket type, as defined in [**zmq\_socket**(3)](/zmq_socket/3.md). By contrast, following a libzmq:zmq\_connect\[3\], the socket enters the *ready* state.

## RETURN VALUE

The *zmq\_bind()* 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.

**EADDRINUSE**

The requested *address* is already in use.

**EADDRNOTAVAIL**

The requested *address* was not local.

**ENODEV**

The requested *address* specifies a nonexistent interface.

**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

**Binding a publisher socket to an in-process and a TCP transport**.

```
/* Create a ZMQ_PUB socket */
void *socket = zmq_socket (context, ZMQ_PUB);
assert (socket);
/* Bind it to a in-process transport with the address 'my_publisher' */
int rc = zmq_bind (socket, "inproc://my_publisher");
assert (rc == 0);
/* Bind it to a TCP transport on port 5555 of the 'eth0' interface */
rc = zmq_bind (socket, "tcp://eth0:5555");
assert (rc == 0);
```

## SEE ALSO

[**zmq\_connect**(3)](/zmq_connect/3.md) [**zmq\_socket**(3)](/zmq_socket/3.md) [**zmq**(7)](/zmq/7.md)

## 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**.