NAME

       sd_bus_is_open, sd_bus_is_ready - Check whether the a bus connection is open or ready.

SYNOPSIS

       #include <systemd/sd-bus.h>

       int sd_bus_is_open(sd_bus *bus);

       int sd_bus_is_ready(sd_bus *bus);

DESCRIPTION

       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.

       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.

RETURN VALUE

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

ERRORS

       Returned errors may indicate the following problems:

       -ECHILD
           The bus connection has been created in a different process.

NOTES

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

SEE ALSO

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