There are several basic functions which inspect the buses for registered names. Internally they use the basic interface ‘org.freedesktop.DBus’, which is supported by all objects of a bus.
This function returns the D-Bus service names, which can be activated. An activatable service is described in a service registration file. Under GNU/Linux, such files are located at /usr/share/dbus-1/services/.
The result is a list of strings, which is
nilwhen there are no activatable service names at all.
All service names, which are registered at D-Bus bus, are returned. The result is a list of strings, which is
nilwhen there are no registered service names at all. Well known names are strings like ‘org.freedesktop.DBus’. Names starting with ‘:’ are unique names for services.bus must be either the symbol
:systemor the symbol:session.
Retrieves all services which correspond to a known name in bus. A service has a known name if it doesn't start with ‘:’. The result is a list of strings, which is
nilwhen there are no known names at all.bus must be either the symbol
:systemor the symbol:session.
For a given service, registered at D-Bus bus under the name service, all queued unique names are returned. The result is a list of strings, or
nilwhen there are no queued names for service at all.bus must be either the symbol
:systemor the symbol:session. service must be a known service name as string.
For a given service, registered at D-Bus bus under the name service, the unique name of the name owner is returned. The result is a string, or
nilwhen there exist no name owner of service.bus must be either the symbol
:systemor the symbol:session. service must be a known service name as string.
Check whether the service name service is registered at D-Bus bus. service might not have been started yet, it is autostarted if possible. The result is either
tornil.bus must be either the symbol
:systemor the symbol:session. service must be a string. timeout, a nonnegative integer, specifies the maximum number of millisecondsdbus-pingmust return. The default value is 25,000. Example:(message "%s screensaver on board." (cond ((dbus-ping :session "org.gnome.ScreenSaver" 100) "Gnome") ((dbus-ping :session "org.freedesktop.ScreenSaver" 100) "KDE") (t "No")))If it shall be checked whether service is already running without autostarting it, one shall apply
(member service (dbus-list-known-names bus))