Thread Subject:

How to write a "version tracking/backup" function?

Assume I have an ADD which I need to modify many times. I want to keep the record of what it has been modified.

I want to write up a BACKUP function which only need to attach a single command line in ADD to do the backup.

function [x] = add(a,b)
   BACKUP();
x = a+b;
end


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the backup will open a txt file and save all char below the command line to the txt file. I can open and write a file, but I have no clue how to do "save all char below the command line" to the txt file

OR
 Any other idea?