dbus-monitor Man page



dbus-monitor – debug probe to print message bus messages


dbus-monitor [–system | –session | –address ADDRESS] [–profile |
–monitor | –pcap | –binary] [watch expressions]


The dbus-monitor command is used to monitor messages going through a
D-Bus message bus. See http://www.freedesktop.org/software/dbus/ for
more information about the big picture.

There are two well-known message buses: the systemwide message bus
(installed on many systems as the “messagebus” service) and the
per-user-login-session message bus (started each time a user logs in).
The –system and –session options direct dbus-monitor to monitor the
system or session buses respectively. If neither is specified,
dbus-monitor monitors the session bus.

dbus-monitor has two different text output modes: the ‘classic’-style
monitoring mode, and profiling mode. The profiling format is a compact
format with a single line per message and microsecond-resolution timing
information. The –profile and –monitor options select the profiling
and monitoring output format respectively.

dbus-monitor also has two binary output modes. The binary mode,
selected by –binary, outputs the entire binary message stream (without
the initial authentication handshake). The PCAP mode, selected by
–pcap, adds a PCAP file header to the beginning of the output, and
prepends a PCAP message header to each message; this produces a binary
file that can be read by, for instance, Wireshark.

If no mode is specified, dbus-monitor uses the monitoring output

In order to get dbus-monitor to see the messages you are interested in,
you should specify a set of watch expressions as you would expect to be
passed to the dbus_bus_add_match function.

The message bus configuration may keep dbus-monitor from seeing all
messages, especially if you run the monitor as a non-root user.


Monitor the system message bus.

Monitor the session message bus. (This is the default.)

–address ADDRESS
Monitor an arbitrary message bus given at ADDRESS.

Use the profiling output format.

Use the monitoring output format. (This is the default.)

Here is an example of using dbus-monitor to watch for the gnome typing
monitor to say things

dbus-monitor “type=’signal’,sender=’org.gnome.TypingMonitor’,interface=’org.gnome.TypingMonitor'”


dbus-monitor was written by Philip Blundell. The profiling output mode
was added by Olli Salli.


Please send bug reports to the D-Bus mailing list or bug tracker, see

D-Bus 1.10.6 DBUS-MONITOR(1)