ref: 1eae6de89dda9f3613ea0ae660e7d5d05b107276 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] }