---
name: "sd_bus_message_copy"
section: "3"
platform: "linux"
package: "systemd-libs"
version: "262.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/sd_bus_message_copy"
---

# sd\_bus\_message\_copy(3)

Copy the contents of one message to another

## NAME

sd\_bus\_message\_copy - Copy the contents of one message to another

## SYNOPSIS

```
#include <systemd/sd-bus.h>
```

**int sd\_bus\_message\_copy(sd\_bus\_message \****m***, sd\_bus\_message \****source***, int** *all***);**

## DESCRIPTION

**sd\_bus\_message\_copy()** copies the contents from message *source* to *m*. If *all* is false, a single complete type is copied (basic or container). If *all* is true, the contents are copied until the end of the currently open container or the end of *source*.

## RETURN VALUE

On success, this call returns true if anything was copied, and false if there was nothing to copy. On failure, it returns a negative errno-style error code.

### Errors

Returned errors may indicate the following problems:

**-EINVAL**

*source* or *m* are **NULL**.

**-EPERM**

Message *m* has been sealed or *source* has *not* been sealed.

**-ESTALE**

Destination message is in invalid state.

**-ENXIO**

Destination message cannot be appended to.

**-ENOMEM**

Memory allocation failed.

## NOTES

Functions described here are available as a shared library, which can be compiled against and linked to with the **libsystemd** [**pkg-config**(1)](/pkg-config/1.md) file.

All functions listed here are thread-agnostic and only a single thread may operate on a given object at any given time. Different threads may access the same object at different times. Multiple independent objects may be used from different threads in parallel.

The code described here uses [**getenv**(3)](/getenv/3.md), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not call [**setenv**(3)](/setenv/3.md) from a parallel thread. It is recommended to only do calls to **setenv()** from an early phase of the program when no other threads have been started.

## SEE ALSO

[**systemd**(1)](/systemd/1.md), [**sd-bus**(3)](/sd-bus/3.md), [**sd\_bus\_message\_append**(3)](/sd_bus_message_append/3.md)