9：golang的Command一次执行多条命令

func DecodeFts(cipherpath, ftspath, password string) (err error) {
    if len(password) != 7 {
        return
    }
    log.Println(ftspath, filepath.Dir(ftspath), filepath.Base(ftspath))
    os.Chdir(filepath.Dir(ftspath))
    cmd := exec.Command(cipherpath, filepath.Base(ftspath))
    inr, inw := io.Pipe()
    outr, outw := io.Pipe()
    cmd.Stdin = inr
    cmd.Stdout = outw
    if err = cmd.Start(); err != nil {
        return
    }
    go cmd.Wait()
    strs := []string{
        "PRAGMA key = '" + password + "';",
        "PRAGMA cipher = 'aes-256-cbc';",
        "PRAGMA cipher_use_hmac = ON;",
        "PRAGMA cipher_page_size = 4096;",
        "PRAGMA kdf_iter = 64000;",
        ".backup fts_de.db",
        ".q",
    }
    for _, str := range strs {
        _, err = encode(bufio.NewReader(outr), inw, str)
        if err != nil {
            log.Println(err.Error())
            return err
        }
    }
    return
}
func encode(r *bufio.Reader, w io.Writer, str string) (string, error) {
    n, err := w.Write([]byte(str))
    if err != nil {
        log.Println(n, err.Error())
        return "", err
    }
    n, err = w.Write([]byte("\n"))
    if err != nil {
        log.Println(n, err.Error())
        return "", err
    }
    return "", err
}