package cli import ( "errors" "fmt" "io" "net/http" "strings" ) type GetCmd struct { URL string `short:"u" help:"Shorty URL (SHORTY_URL)" default:"${url}"` Path string `arg:"" help:"Redirect path"` } func (c *GetCmd) Run(ctx *Context) error { url := strings.Join([]string{c.URL, c.Path}, "") req, err := http.NewRequest(http.MethodGet, url, nil) if err != nil { return err } // Create a specialized client that ignores redirection client := &http.Client{ CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }, } res, err := client.Do(req) if err != nil { return err } if res.StatusCode == http.StatusNotFound { return nil } else if res.StatusCode != http.StatusPermanentRedirect { body, err := io.ReadAll(res.Body) if err != nil { return err } if len(body) > 0 { return errors.New(string(body)) } return errors.New(res.Status) } dest := res.Header.Get("location") fmt.Println(dest) return nil } func (c *GetCmd) Validate() error { if len(c.Path) < 1 || c.Path[0] != '/' { return errors.New("invalid ") } return nil }