How to use the system task scheduler in your own program?

Question

linux

Greetings!
I am writing a program, its task is to hang in the background and collect statistics on a schedule, and transfer them to the server.
After deliberation, it was decided to abandon writing our own scheduler and use the system one.
But here problems arose - how to run actions that are registered in the scheduler as program parameters if the program hangs in the background? those. running another copy is not an option.
It is necessary to somehow transfer the parameters to the already running program for processing.
What is the best way to do this?
PS cross-platform program I want to avoid crutches and make it native Qt.
PPS not using files or sockets, this is an overkill in my opinion.
PPS something like in Notepad ++ instead of opening a copy, another tab opens

Answer 1

Notepad launches another instance that kicks (yes, either through a socket (which is portable) or through window messages) a running instance, then closes.
You will have to do the same.