Re^3: A regex that only matches at offset that are multiples of a given N?

[smls]

in reply to Re^2: A regex that only matches at offset that are multiples of a given N?
in thread A regex that only matches at offset that are multiples of a given N?

Mixing the freds at different multiple boundaries within the same string is a very neat way of testing.

I can't take credit for that, it was copied from johngg's answer. I just made it a little more readable.