DOKK / manpages / debian 10 / dbus / dbus-monitor.1.en
DBUS-MONITOR(1) User Commands DBUS-MONITOR(1)

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 format.

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.

--system

Monitor the system message bus.

--session

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

--address ADDRESS

Monitor an arbitrary message bus given at ADDRESS.

--profile

Use the profiling output format.

--monitor

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 http://www.freedesktop.org/software/dbus/

D-Bus 1.12.20