sd_bus_slot_set_description, sd_bus_slot_get_description - Set or query the description of bus slot objects


#include <systemd/sd-bus.h>

int sd_bus_slot_set_description(sd_bus_slot* slot, const char *description);

int sd_bus_slot_get_description(sd_bus_slot* bus, const char **description);


sd_bus_slot_set_description() sets the description string that is used in logging to the specified string. The string is copied internally and freed when the bus slot object is deallocated. The description argument may be NULL, in which case the description is unset.

sd_bus_slot_get_description() returns a description string in description. If the string is not set, e.g. with sd_bus_slot_set_description(), and the slot is a bus match callback slot, the match string will be returned. Otherwise, -ENXIO is returned.


On success, these functions return 0 or a positive integer. On failure, they return a negative errno-style error code.

Returned errors may indicate the following problems:


An required argument is NULL.


The bus slot object has no description.


Memory allocation failed.


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

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.


sd_bus_slot_set_description() and sd_bus_slot_get_description() were added in version 240.


systemd(1), sd-bus(3) sd_bus_slot_ref(3), sd_bus_slot_set_userdata(3)