Continuing a program after leaving minecraft

Basically, I am making a land clearing program. However, after shutting off Minecraft, and starting it again, it stops the program. I have heard that you can edit a file from inside a program, so I have a vague idea of storing the variables in a program everytime they change, and be able to start where you left off from. I have no idea how to make some code like this, or even how it would really work. How would I do this, or is it even possible?

You would need to save the state of the clearing in a file and when you log back into minecraft that file will be loaded to tell the turtle where it left off.

Code would be

local file = fs.open("sampleFile", "w")
file.write("Your variables")
file.close()
local f = fs.open("sampleFile", "r")
local sCont = f.readAll()
f.close()
print(sCont)

Though you should be aware, it might not save if you for example log out during a turtle movement or such, because then it might not have time to actually record the movement