ref: a3b68e649d2da36d19d78106134d1114f06b56e1 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 }