golang 获取一字符串

/*KC_RAND_KIND_NUM = 0 // 纯数字

KC_RAND_KIND_LOWER = 1 // 小写字母

KC_RAND_KIND_UPPER = 2 // 大写字母

KC_RAND_KIND_ALL = 3 // 数字、大小写字母

func Krand(size int, kind int) []byte  {

    ikind, kinds, result :=
    kind, [][]int{[]int{10, 48}, []int{26, 97}, []int{26, 65}}, make([]byte, size)

    is_all := kind > 2 || kind < 0
    rand.Seed(time.Now().UnixNano())
    
    for i :=0; i < size; i++ {
    if is_all { // random ikind
    	ikind = rand.Intn(3)
    }
    scope, base := kinds[ikind][0],     kinds[ikind][1]
    result[i] = uint8(base+rand.Intn(scope))
    }
   return result
}