[KDE4] what component does the screenlocking?

[René J. V. Bertin]

Luca Beltrame wrote:

> With the exception of "loginctl unlock-sessions" as root or "loginctl unlock-
> session" as the same user, none. It's the whole point of the screenlocker
> architecture (that is, you can't just kill it and unlock the screen).

And is that loginctl command supposed to work only on systems that use systemd 
throughout or elsewhere too? `loginctl kill-session X` works for me but not 
`loginctl lock-session X` or `loginctl unlock-session X`, is that because Ubuntu 
14.04 only pretends to use systemd and (AFAIK) uses upstart for most things?

R.