dbus_trace 0.1

dbus-trace is a wrapper to see what D-Bus messages a program sends and receives.

Installation:

pip install dbus-trace

Usage:

dbus-trace <command>

# For example - notify-send creates a desktop notification using D-Bus
$ dbus-trace notify-send "Hello world"

* Connected to session bus (connection 0)
◀ method_call: Hello [serial = 1]
  path = /org/freedesktop/DBus
  interface = org.freedesktop.DBus
  destination = org.freedesktop.DBus

...

◀ method_call: Notify [serial = 7]
  path = /org/freedesktop/Notifications
  interface = org.freedesktop.Notifications
  destination = :1.44
  Data (susssasa{sv}i): (
       'notify-send',
       0,
       '',
       'Hello world',
       '',
       [],
       {'sender-pid': ('x', 31559), 'urgency': ('y', 1)},
       -1,
    )

▷ method_return:  [serial = 88]
  Flags: 1 (no_reply_expected)
  destination = :1.944
  reply_serial = 7
  sender = :1.44
  Data (u): (8,)

...

dbus-trace listens on Unix sockets for the system bus and the session bus, and passes through any data sent to these sockets to the real buses. It runs the child program with environment variables pointing it to use these proxy sockets, and of course it decodes what’s going through and prints it to the terminal.

For more background about D-Bus, see What is D-Bus?.