[Go] Simple usage of flag package

app.go

package main

import (
    "fmt"
    f "flag"
)

var Flag = func() string {
    var used string
    f.Visit(func(fg *f.Flag) {
        used = fg.Name
    })
    return used
}

func init() {
    f.Bool(
                 "v", false,
        "Print the version",
    )
    f.Parse()
}

func main() {
    switch Flag() {
    case "v":
        fmt.Println("0.1.0")
    default:
        f.Usage()
    }
}