sd_bus_start - Man Page

#include <systemd/sd-bus​.h>

int sd_bus_start(sd_bus *bus);

sd_bus_start() connects an existing bus connection object to the D-Bus broker daemon, usually dbus-daemon(1) or dbus-broker(1)​. The mechanism to use for the connection must be configured before the call to sd_bus_start(), using one of sd_bus_set_address(3), sd_bus_set_fd(3), or sd_bus_set_exec(3)​. sd_bus_start() will open the connection socket or spawn the executable as needed, and asynchronously start a org​.freedesktop​.DBus​.Hello() call​. The answer to the Hello call will be processed later from sd_bus_process(3)​. If opening of the connection or queuing of the asynchronous call fail, the connection will be closed with sd_bus_close(3)​.

In most cases, it is better to use sd_bus_default_user(3), sd_bus_default_system(3) or related calls instead of the more low-level sd_bus_new() and sd_bus_start()​. The higher-level functions not only allocate a bus object but also start the connection to a well-known bus in a single function call​.

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

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​.

sd_bus_start() was added in version 246​.

systemd(1), sd-bus(3), sd_bus_default(3), sd_bus_call_async(3)