ref: 6d0ade9e0f10517872304e94c2c5d0e3a14c426d 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 }