Index · Directives systemd 261.2

Name

sd_bus_get_name_machine_id — Retrieve a bus client's machine identity

Synopsis

#include <systemd/sd-bus.h>
int sd_bus_get_name_machine_id(sd_bus *bus,
 const char *name,
 sd_id128_t *machine);
 

Description

sd_bus_get_name_machine_id() retrieves the D-Bus machine identity of the machine that the bus client identified by name is running on. Internally, it calls the GetMachineId method of the org.freedesktop.DBus.Peer interface. The D-Bus machine identity is a 128-bit UUID. On Linux systems running systemd, this corresponds to the contents of /etc/machine-id. On success, the machine identity is stored in machine.

Return Value

On success, this function returns a non-negative integer. On failure, it returns a negative errno-style error code.

Errors

Returned errors may indicate the following problems:

-EINVAL

An argument is invalid.

-ENOPKG

The bus cannot be resolved.

-ECHILD

The bus was created in a different process, library or module instance.

-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) 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), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not call setenv(3) 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_get_name_machine_id() was added in version 221.

See Also

systemd(1), sd-bus(3)