[...] You can put a '+' in front of the '>' or '<' to indicate you want both read and write access to the file; thus '+<' is almost always preferred for read/write updates--the '+>' mode would clobber the file first.
It doesn't. I never claimed it will. The data file I use,
I originally seeded by hand.
If I have given the suggestion the code I posted is something
you can just download and run everywhere, I've given the
wrong impression. I just posted code that runs daily on my
system, and that was developped purely to run on my system.
It was posted mainly for educational and illustrational purposes.
It should run on many systems, but some assembly will be required.