I would probably do it this way: tr -dc A-Za-z0-9 </dev/urandom | dd count=1 bs=16 2>/dev/null; echo A few less characters to type, you get your newline, and

I would probably do it this way: tr -dc A-Za-z0-9 </dev/urandom | dd count=1 bs=16 2>/dev/null; echo A few less characters to type, you get your newline, and shellcheck doesn't complain.