sd_bus_is_open - Man Page

#include <systemd/sd-bus​.h>

int sd_bus_is_open(sd_bus *bus);

int sd_bus_is_ready(sd_bus *bus);

sd_bus_is_open() checks whether the specified bus connection is open, i​.e​. in the process of being established, already established or in the process of being torn down​. It returns zero when the connection has not been started yet (i​.e​. sd_bus_start(3) or some equivalent call has not been invoked yet), or is fully terminated again (for example after sd_bus_close(3)), it returns positive otherwise​.

sd_bus_is_ready() checks whether the specified connection is fully established, i​.e​. completed the connection and authentication phases of the protocol and received the Hello() method call response, and is not in the process of being torn down again​. It returns zero outside of this state, and positive otherwise​. Effectively, this function returns positive while regular messages can be sent or received on the connection​.

The bus argument may be NULL, zero is also returned in that case​.

To be notified when the connection is fully established, use sd_bus_set_connected_signal(3) and install a match for the Connected() signal on the "org​.freedesktop​.DBus​.Local" interface​. To be notified when the connection is torn down again, install a match for the Disconnected() signal on the "org​.freedesktop​.DBus​.Local" interface​.

Those functions return 0 if the bus is not in the given state, and a positive integer when it is​. On failure, a negative errno-style error code is returned​.

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_is_open() was added in version 221​.

sd_bus_is_ready() was added in version 237​.

systemd(1), sd-bus(3), sd_bus_start(3), sd_bus_close(3), sd_bus_set_connected_signal(3)

sd-bus(3), sd_bus_set_connected_signal(3), sd_bus_set_watch_bind(3), systemd.directives(7), systemd.index(7).

The man page sd_bus_is_ready(3) is an alias of sd_bus_is_open(3).