---
name: "sd_bus_message_read_strv"
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_read_strv"
---

# sd\_bus\_message\_read\_strv(3)

Access an array of strings in a message

## NAME

sd\_bus\_message\_read\_strv, sd\_bus\_message\_read\_strv\_extend - Access an array of strings in a message

## SYNOPSIS

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

**int sd\_bus\_message\_read\_strv(sd\_bus\_message \****m***, char \*\*\****l***);**

**int sd\_bus\_message\_read\_strv\_extend(sd\_bus\_message \****m***, char \*\*\****l***);**

## DESCRIPTION

**sd\_bus\_message\_read\_strv()** reads an array of string-like items from the message *m*. The "read pointer" in the message must be right before an array of strings (D-Bus type "as"), object paths (D-Bus type "ao"), or signatures (D-Bus type "ag"). On success, a pointer to a **NULL**-terminated array of strings (strv) is returned in the output parameter *l*. Note that ownership of this array is transferred to the caller. Hence, the caller is responsible for freeing this array and its contents. Also note that as a matter of optimization, if an empty array is encountered a **NULL** pointer might be returned here, and should be considered equivalent to an array with zero entries.

**sd\_bus\_message\_read\_strv\_extend()** is similar, but the second parameter is an input-output parameter. If *\*l* is **NULL**, if behaves identically to **sd\_bus\_message\_read\_strv()**. Otherwise, *\*l* must point to a strv, which will be reallocated and extended with additional strings. This function is particularly useful when combining multiple lists of strings in a message or messages into a single array of strings.

## RETURN VALUE

On success, these functions return a non-negative integer. On failure, they return a negative errno-style error code.

### Errors

Returned errors may indicate the following problems:

**-EINVAL**

*m* or *l* are **NULL**.

Added in version 246.

**-EPERM**

The message is not sealed.

Added in version 246.

**-EBADMSG**

The message cannot be parsed.

Added in version 246.

**-ENXIO**

The message "read pointer" is not right before an array of the appropriate type.

Added in version 248.

## 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.

## HISTORY

**sd\_bus\_message\_read\_strv()** was added in version 246.

**sd\_bus\_message\_read\_strv\_extend()** was added in version 252.

## SEE ALSO

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