Hi everyone,

I recently switched from Xfce/GNOME2 to window managers, thus having no longer need in dbus (it's Debian, so I still have a dbus library but not the daemons). I wonder, what are advantages of using dbus.

Let me explain: to change preferences/look of a window manager (or any other programme that doesn't use dbus; xterm for example) one has to edit its configuration file(s). And to change, say, xfwm4/metacity theme (font, etc.) one has to type a command (xfconf-query...), apart from GUI configuration manager, of course, OR to change XML config files manually, but, without dbus running, settings won't work.

So, why don't then these environments (GNOME, KDE, Xfce) only rely on plain text config files for managing their components without need in dbus?

Thanks

From the same developers as systemd... Dbus originally was just another inter-process communication method that allowed addressing (like rpc services do, but using a different addressing scheme). The developers wormed it into being used for anything and everything. It is embedded in systemd as well. It has been used to pass audio around, configuration options, system daemon to user notifications...

Personally, I prefer simple text files (even XML is overkill, and hard to read as well; so suddenly you get yet another GUI editor for those files...).

One of the issues dbus does address is to separate the X resource database portion of the X server (which still exists) from the X server. This is not necessarily a bad thing, but it does force yet another authentication and authorization problem with X applications working remotely (the "can't contact dbus" is due to the addressing failure between a remote application and the local resource definitions...), which makes some gnome tools act odd.

The problem this causes is that it becomes a problem for the Mate desktop as the Mate toolkit libraries have been being migrated to qt3 (which is a gnome3 library where the dbus connections get involved). Trying to use some of those tools remotely causes problems.

D-Bus is, by the way, maintained by Red Hat. I see some similarities with systemd as well. But D-Bus has been here for long time and I have never really questioned, why should I use it, unlike with systemd case. It's another topic though.

As far as I know, systemd's dbus (sd-bus) is another implementation, like GDBus and QtDBus, built on top of it.

I had some problems with dbus, in particular with permissions and policykit (unable to shutdown and mounting volumes, it was in Xfce and Mate). gvfs is another huge thing, of which I am a bit uncertain.

Mate uses gtk+2, no? Last time I used it was 1.8 though, but since it's "enhanced GNOME2," I reckon, they'll be using it.

Mate is moving to gtk3 (http://wiki.mate-desktop.org/status:gtk3), though the project hasn't finished. The advantage for the project is not having to maintain the gtk2 libraries anymore. The disadvantage to the users is that it will come with a good bit of the gnome3 baggage originally avoided.

There is only one dbus - the others are interface libraries added to access it.

Part of gvfs is now missing (the user fuse mount for the gnome configuration), at least in Fedora (but them I'm using gnome2, but see things like gvfsd, gvfsd-http, gvfsd-metadata,.... So it appears to be reimplemented on the /run/user/<uid>/gvfs things that get wiped out on logout. At least backups don't seem to have a problem with it now.

I received a reply, regarding D-Bus, on Xfce forums that is worth sharing, I suppose.

yep its communication software got a have it, or simular software to communicate. Just like drivers are communication software.

You need it only because applications use it. There ARE alternative communications methods. Domain sockets are used for dbus... so dbus itself isn't required, just that the applications use it instead.

Which is more complex to use? Personally, it looks like dbus is.