But that's not what I want. I need the files created by the outer loop (the "$val1.txt" ones) for later work (next week maybe, when I get around to programming it), and I need to know exactly which is which.

What I don't necessarily need is the output from the 2nd step. I would rather have just 2 files, but I don't know yet how to do it. I used to simply open two files and print to them accordingly, but the input was all jumbled, and I was told to use pipes instead. And here I am up to my knees in parents and children again :-/