ref: 07f04384230b0c4cb8c47da7b5a6aebdea992b1e dir: /testdir/t.set0/
{$0 = $1; print; print NF, $0; print $2} {$(0) = $1; print; print NF, $0; print $2} { i = 1; $(i) = $i+1; print }