package kingpin_parser

import (

    "strconv"

    "gopkg.in/alecthomas/kingpin.v2"

    "fmt"

)

type size uint64

//单位换算

func (s *size) Set(value string) error {

    num, err := strconv.ParseUint(value[:len(value) - 1], 10, 64)

    if err != nil {

        return fmt.Errorf("can't parse \"%s\"", value)

    }

    switch value[len(value) - 1] {

    case 'B', 'b':

    case 'K', 'k':

        num = num << 10

    case 'M', 'm':

        num = num << 20

    case 'G', 'g':

        num = num << 30

    default:

        return fmt.Errorf("can't parse \"%s\"", value)

    }

    *s = size(num)

    return nil

}

//数据支持标准输出

func (s *size) String() string {

    return strconv.FormatUint(uint64(*s), 10)

}

//字节大小设置

func Size(s kingpin.Settings) (target *uint64) {

    target = new(uint64)

    s.SetValue((*size)(target))

    return

}