ref: 6d0ade9e0f10517872304e94c2c5d0e3a14c426d dir: /test/t.split3/
{ a = $0 " " $0 " " $0 if ($1 != "") n = split (a, x, "[" $1 "]") print n, x[1], x[2], x[3], x[4] }