[systemd-devel] XDG standardization for applications – allow using dash delimited names in application's unit name

[Piotr Dobrogost]

Hi,

At https://systemd.io/DESKTOP_ENVIRONMENTS/ there's suggested scheme
for automatically generated unit's name:
app[-<launcher>]-<ApplicationID>[@<RANDOM>].service

I have the following .desktop files:
piotr at demon:~/.local/share/applications$ ls
jetbrains-pycharm-2024.2.desktop
jetbrains-pycharm-2024.3.desktop

When I start application using the first one above KDE creates the
following transient unit:
app-jetbrains\x2dpycharm\x2d2024.2 at a99c48aaf53a4b4f9f395db78cca4b5a.service
,where dashes ("-") in the name of .desktop file have been escaped with "\x2d".

The problem with this is that I can't create convenient drop-in directories like
app-jetbrains-.service.d
or
app-jetbrains-pycharm-.service.d
to have custom settings for all jetbrains applications and/or custom
settings for all pycharm instances.

Is the escaping performed by KDE here mandated by the specification at
https://systemd.io/DESKTOP_ENVIRONMENTS/ (specifically, by fragment
"If no application ID is available, the launcher should generate a
reasonable name when possible (e.g. using basename(argv[0])). This
name must not contain a - character.")?
Could the specification be amended to explicitly allow any number of
dash delimited names between <launcher> (or "app" when there's no
<launcher> used) and <ApplicationID> segments that Desktop Environment
deems necessary to facilitate fine-grained control of launched
applications based on dashes used in .desktop filenames?

I first observed this usability problem in my comment at
https://discuss.kde.org/t/limit-application-memory-usage-with-systemd-kde-blogs/23804/11?u=piotr_dobrogost
in the discussion pertaining to "Limit Application Memory Usage with
systemd" blog post at
https://blogs.kde.org/2024/10/18/limit-application-memory-usage-with-systemd/


Regards,
Piotr Dobrogost