---
name: "dbus-monitor"
section: "1"
platform: "linux"
package: "dbus"
version: "1.16.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/dbus-monitor"
---

# dbus-monitor(1)

debug probe to print message bus messages

## NAME

dbus-monitor - debug probe to print message bus messages

## SYNOPSIS

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

## DESCRIPTION

The **dbus-monitor** command is used to monitor messages going through a D-Bus message bus. See **https://www.freedesktop.org/wiki/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.

## OPTIONS

- **--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.)

## EXAMPLE

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'"
```

## AUTHOR

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

## BUGS

Please send bug reports to the D-Bus mailing list or bug tracker, see **https://www.freedesktop.org/wiki/Software/dbus/**