Automatic backups

Now for a bit of free programming advice, making automatic backups of files was mentioned in Chapter 4, Creating and Calling Subroutines. I strongly suggest you use something like this when you are writing anything that is even slightly complicated. There is nothing more frustrating than to be working on your program or script and have it going pretty well, only to make a few changes and have it fail in some bizarre fashion. You had it working a few minutes ago and then wham! It has a fault and you can't figure out what change caused it. If you don't have a numbered backup you could literally spend hours (maybe days) trying to find the bug. I have seen people spend hours backing out every change until the problem was found. Yes, I have done it too.

Obviously if you have a numbered backup you can simply go back and find the latest one that doesn't have the fault. You can then diff the two versions and probably find the error really fast. Without a numbered backup, well you...