---
name: "sd_bus_can_send"
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_can_send"
---

# sd\_bus\_can\_send(3)

Check which types can be sent over a bus object

## NAME

sd\_bus\_can\_send - Check which types can be sent over a bus object

## SYNOPSIS

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

**int sd\_bus\_can\_send(sd\_bus \****bus***, char** *type***);**

## DESCRIPTION

**sd\_bus\_can\_send()** is mostly used for checking if file descriptor passing is available on the given bus. *type* can be any of the **SD\_BUS\_TYPE** constants.

## RETURN VALUE

On failure, **sd\_bus\_can\_send()** returns a negative errno-style error code. If values of the given type can be sent over the given bus, it returns a positive integer. Otherwise, it returns zero.

### Errors

Returned errors may indicate the following problems:

**-ENOPKG**

The bus object *bus* could not be resolved.

**-ENOTCONN**

The input parameter *bus* is **NULL** or the bus is not connected.

**-ECHILD**

The bus object *bus* was created in a different process.

## 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\_can\_send()** was added in version 221.

## SEE ALSO

[**systemd**(1)](/systemd/1.md), [**sd-bus**(3)](/sd-bus/3.md)