ref: 7e6d7d36f83f05f372cfbce43534a2747bfc39c3 dir: /test/t.set0/
{$0 = $1; print; print NF, $0; print $2} {$(0) = $1; print; print NF, $0; print $2} { i = 1; $(i) = $i+1; print }