用dbus-send查看当前system bus或者session bus上面挂载了多少service.

引用自：

http://blog.csdn.net/cuijpus/article/details/2455173

test@test-desktop:~$ dbus-send --system --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.ListActivatableNames

test@test-desktop:~$ dbus-send --session --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.ListActivatableNames