[ptaffs]

I understood the point of the question was how shells work seems very context driven. An & here means something different to an & there. IFS=\| read A B C <<< "first|second|third" the read is executed and the IFS assignment is local to the one command echo hello this will "hello this", even though in the assignment above the space was important an & at the end of a line is run the task background and in the middle of the redirect isn't. All these things can be learned, but it's hard to explain the patterns, I think.