ref: c0f4e97e4561ff42544e92512bbaf3d7d1f6a671 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 }