How to access daemon's I/O threads in linux?

Question

linux

My program has this structure:

def UserInterface():
    while(True):
        print("hello")
        tmp = input()
        ...

def payload():
    while(True):
        #Something code

def main():
    Thread(target=UserInterface, args=()).start()
    Thread(target=payload, args=()).start()

There are two threads running in an endless loop. The first thread is a text interface through which you can receive commands from the user and display information to him. The second stream is the "payload".
I run the program with a command from the terminal and all is well. But I want to run my program as a daemon via systemd. If I do this, how can I get the opportunity to interact with the program?

Answer 1

The normal daemon doesn't work through stdin/stdout/stderr. You should look towards named pipe or unix socket - these are such special files. And ideally, you need to interact via TCP so that you can cling to the telnet program there (but better - with encryption, via ssh).