string-slice-flag.go

type Foo struct {
        value []string
}

func (f *Foo) String() string {
        return ""
}

func (f *Foo) Set(s string) error {
        f.value = append(f.value, s)
        return nil
}

var foo = Foo{}

func main() {
        flag.Var(&foo, "foo", "foo")
        flag.Parse()
        log.Printf("%#v", foo)
}