How to use QT to control pins and signals in Linuxcnc via shared memory?

1.Now I have a signal called qqq
u@u-desktop:~$ sudo halcmd show sig qqq
Signals:
Type          Value  Name     (linked to)
bit           FALSE  qqq

2.The signal changes when I execute the following code in QT
halcmdsets("qqq","1");

3.The value of the signal is now true
u@u-desktop:~$ sudo halcmd show sig qqq
Signals:
Type          Value  Name     (linked to)
bit            TRUE  qqq

Finally, how should I write the halcmdsets? My English level is relatively poor, please forgive me for the improper description.
 

In the C++ language I use in QT, I want to change both the signal and the pin. I looked at the files in LinuxCNC and found the hal_lib.c file, which can help me realize the idea of changing signal values and pin values in QT. But now I have this idea but I don't know how to implement it using QT.

Ok, I will analyze the file halModulo. c, may I ask whether I can contact you through any chat software? I would like to continue to consult you about this aspect.

Why do you need this signal? And how did you create it. (Python / C++) Maybe you need to attach to an already existing one. and hang it on the button.

@TheRoslyak
That post is likely a spam setup.
First post with female username and some ChatGPT result to something found in an old thread. Then the actual spam link is added later on.

how to use hal with qt
This is old, but gives you info.