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