systembus-notify - system bus notification daemon

Tiny daemon that listens for net.nuetzlich.SystemNotifications.Notify signals on the D-Bus system bus and shows them as desktop notifications using the user bus. Works on Linux with Gnome, Cinnamon, KDE, LXQT, ...

See rfjakob/earlyoom#183 for the raison d'être.

Compile

Just run

make

If you want systembus-notify to automatically start when you log in, also run (no sudo required):

make install

Test

Just run

make test

You should see "systembus-notify test" as a desktop notification.

Or manually:

./systembus-notify &
dbus-send --system / net.nuetzlich.SystemNotifications.Notify 'string:summary text only'
dbus-send --system / net.nuetzlich.SystemNotifications.Notify 'string:summary text' 'string:and body text'

Dependencies

systembus-notify uses the sd-bus D-Bus library that is part of libsystemd. Install it like this:

Debian / Ubuntu

sudo apt install libsystemd-dev

Fedora

sudo dnf install systemd-devel

Send notifications from your service

The simplest way is to call the dbus-send tool.

Shell:

dbus-send --system / net.nuetzlich.SystemNotifications.Notify "string:hello world"

C (don't use system(), it's insecure!):

int pid = fork();
if (pid == 0)
	execl("/usr/bin/dbus-send", "dbus-send", "--system", "/", "net.nuetzlich.SystemNotifications.Notify", "string:hello world", NULL);

You can also use libdbus or another d-bus library to send the signal. In any case, systembus-notify must be running for the notification to pop up.

See Also

Original idea is from https://wiki.debianforum.de/Desktop-Notification_von_Systemservice_mittels_dbus (German).

Similar thing implemented in Python: https://github.com/xundeenergie/system-notification