How to edit common function using a script

[pouralise]

Can you explain why do you need this?

I have some Logic Machines (LMs) in several projects. And I have write some new functions in the newest project and want to have this function in every LMs. I will check the other LMs to see if they have the function or not, if they doesnt have the function then I will add that function to the common funtion. Of course all the work will be done by a script. I can't just copy all common function because each of LMs has some different fix variable (like, email, password, position...) so it's best if I only add the new function to all of the LMs that I've done.
While waiting your answer, I've already thought about add the new function to user libraries but I am still prefer to add it to common function.