ref: 2a3ee1c2e3e1ea6477ca8715bf1531dbf34367a1 dir: /testdir/t.split3/
{ a = $0 " " $0 " " $0 if ($1 != "") n = split (a, x, "[" $1 "]") print n, x[1], x[2], x[3], x[4] }