---
name: "zmq_msg_init"
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_msg_init"
---

# zmq\_msg\_init(3)

initialise empty 0MQ message

## NAME

zmq\_msg\_init - initialise empty 0MQ message

## SYNOPSIS

**int zmq\_msg\_init (zmq\_msg\_t** *\*msg***);**

## DESCRIPTION

The *zmq\_msg\_init()* function shall initialise the message object referenced by *msg* to represent an empty message. This function is most useful when called before receiving a message with *zmq\_msg\_recv()*.

**Caution**\

Never access *zmq\_msg\_t* members directly, instead always use the *zmq\_msg* family of functions.

**Caution**\

The functions *zmq\_msg\_init()*, *zmq\_msg\_init\_data()*, *zmq\_msg\_init\_size()* and *zmq\_msg\_init\_buffer()* are mutually exclusive. Never initialise the same *zmq\_msg\_t* twice.

## RETURN VALUE

The *zmq\_msg\_init()* function always returns zero.

## ERRORS

No errors are defined.

## EXAMPLE

**Receiving a message from a socket**.

```
zmq_msg_t msg;
rc = zmq_msg_init (&msg);
assert (rc == 0);
int nbytes = zmq_msg_recv (socket, &msg, 0);
assert (nbytes != -1);
```

## SEE ALSO

[**zmq\_msg\_init\_size**(3)](/zmq_msg_init_size/3.md) [**zmq\_msg\_init\_buffer**(3)](/zmq_msg_init_buffer/3.md) [**zmq\_msg\_init\_data**(3)](/zmq_msg_init_data/3.md) [**zmq\_msg\_close**(3)](/zmq_msg_close/3.md) [**zmq\_msg\_data**(3)](/zmq_msg_data/3.md) [**zmq\_msg\_size**(3)](/zmq_msg_size/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**.