Go语言库系列之flag

$ flag girl -h
Usage of girl:
  -height int
        身高 (default 140)

$ flag girl --height 170
恭喜你获得了身高 170 的女朋友

import "flag"

var height int

flag.IntVar(&height, "height", 140, "身高")

flag.Parse()

fmt.Println("恭喜你获得了身高", height, "的女朋友")

package main

import (
	"flag"
	"fmt"
)

var height int

func main() {
	flag.IntVar(&height, "height", 140, "身高")
	flag.Parse()
	fmt.Println("恭喜你获得了身高", height, "的女朋友")
}

$ girl -height 170
$ girl --height 170
$ girl --height=170
$ girl -height=170

1, 0, t, f, T, F, true, false, TRUE, FALSE, True, False

type height int

func (h *height) String() string {
	return fmt.Sprint(*h)
}

func (h *height) Set(value string) error {
	valueInt, _ := strconv.Atoi(value)
	*h = height(valueInt - 5)
	return nil
}

var heightFlag height

func main() {
	flag.Var(&heightFlag, "height", "身高")
	flag.Parse()
	fmt.Println(heightFlag)
}