github.com/benhoyt/goawk@v1.8.1/testdata/t.split3 (about)

     1  { a = $0 " " $0 " " $0
     2    if ($1 != "")
     3        n = split (a, x, "[" $1 "]")
     4    print n, x[1], x[2], x[3], x[4] }