seek難しい - Qiita

target, err := ioutil.TempFile("", "zip") if err != nil { sentry.CaptureException(err) log.Fatalln(err) } w := zip.NewWriter(target) defer w.Close() for _, client := range clients { xlsx, err := run(client.ClientID) if err != nil { continue } defer xlsx.Close() f, err := w.Create(fmt.Sprintf("%d_item_error.xlsx", client.ClientID)) if err != nil { sentry.CaptureException(err) log.Fatalln(err) } if