| // Copyright 2018 The Go Authors. All rights reserved. | |
| // Use of this source code is governed by a BSD-style | |
| // license that can be found in the LICENSE file. | |
| package flag_test | |
| import ( | |
| "flag" | |
| "fmt" | |
| "net/url" | |
| ) | |
| type URLValue struct { | |
| URL *url.URL | |
| } | |
| func (v URLValue) String() string { | |
| if v.URL != nil { | |
| return v.URL.String() | |
| } | |
| return "" | |
| } | |
| func (v URLValue) Set(s string) error { | |
| if u, err := url.Parse(s); err != nil { | |
| return err | |
| } else { | |
| *v.URL = *u | |
| } | |
| return nil | |
| } | |
| var u = &url.URL{} | |
| func ExampleValue() { | |
| fs := flag.NewFlagSet("ExampleValue", flag.ExitOnError) | |
| fs.Var(&URLValue{u}, "url", "URL to parse") | |
| fs.Parse([]string{"-url", "https://golang.org/pkg/flag/"}) | |
| fmt.Printf(`{scheme: %q, host: %q, path: %q}`, u.Scheme, u.Host, u.Path) | |
| // Output: | |
| // {scheme: "https", host: "golang.org", path: "/pkg/flag/"} | |
| } | |