double-dash hyphen

main.go

package main

import (
        "flag"
        "fmt"
        "os"
)

var hoge *string
var str string

func init() {
        hoge = flag.String("hoge", "default-value", "First string option")
        flag.StringVar(&str, "str", "default-value", "Second string option")
}

func main() {
        myParse()
        fmt.Println("hoge:", *hoge)
        fmt.Println("str:", str)
}

func myParse() {
        fs := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
        fs.Usage = flag.Usage
        flag.CommandLine.VisitAll(func(f *flag.Flag) {
                fs.Var(f.Value, f.Name, f.Usage)
                fs.Var(f.Value, "-"+f.Name, f.Usage)
        })
        fs.Parse(os.Args[1:])
}