Ubuntu – How to run a script on a dbus signal

automationdbus

Is it possible to run a script on an arbitrary dbus signal? Something like Upstart that runs as an unprivileged user and doesn't require root perms to modify?

I ask because I've already written a silly script that waits for bluetooth events to start my music player. Now I'd like to do something similar when my machine connects to specific networks, or other devices attach.

EDIT: My original question didn't specify this, but I meant "associate a number of scripts with one of a set of events" – so I'd have the same launcher-y thing (like Upstart) that manages a number of scripts, each of which cares about a different dbus signal. All in user space.

Best Answer

You need the dbus-monitor

The script will look something like

#!/bin/bash

interface=org.gnome.Rhythmbox.Player
member=playingUriChanged

# listen for playingUriChanged DBus events,
# each time we enter the loop, we just got an event
# so handle the event, e.g. by printing the artist and title
# see rhythmbox-client --print-playing-format for more output options

dbus-monitor --profile "interface='$interface',member='$member'" |
while read -r line; do
  printf "Now playing: "
  rhythmbox-client --print-playing
done

Taken from stackoverflow.

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