func (c *execCmd) run(config *lxd.Config, args []string) error {
	if len(args) < 2 {
		return errArgs
	}

	remote, name := config.ParseRemoteAndContainer(args[0])
	d, err := lxd.NewClient(config, remote)
	if err != nil {
		return err
	}

	env := map[string]string{"HOME": "/root", "USER": "root"}
	myEnv := os.Environ()
	for _, ent := range myEnv {
		if strings.HasPrefix(ent, "TERM=") {
			env["TERM"] = ent[len("TERM="):]
		}
	}

	for _, arg := range envArgs {
		pieces := strings.SplitN(arg, "=", 2)
		value := ""
		if len(pieces) > 1 {
			value = pieces[1]
		}
		env[pieces[0]] = value
	}

	cfd := syscall.Stdout
	var oldttystate *terminal.State
	if terminal.IsTerminal(cfd) {
		oldttystate, err = terminal.MakeRaw(cfd)
		if err != nil {
			return err
		}
		defer terminal.Restore(cfd, oldttystate)
	}

	ret, err := d.Exec(name, args[1:], env, os.Stdin, os.Stdout, os.Stderr)
	if err != nil {
		return err
	}

	if oldttystate != nil {
		/* A bit of a special case here: we want to exit with the same code as
		 * the process inside the container, so we explicitly exit here
		 * instead of returning an error.
		 *
		 * Additionally, since os.Exit() exits without running deferred
		 * functions, we restore the terminal explicitly.
		 */
		terminal.Restore(cfd, oldttystate)
	}

	/* we get the result of waitpid() here so we need to transform it */
	os.Exit(ret >> 8)
	return fmt.Errorf(gettext.Gettext("unreachable return reached"))
}

func askConfig() (cfg, error) {
	stdinState, err := terminal.MakeRaw(syscall.Stdin)
	if err != nil {
		return cfg{}, err
	}
	defer terminal.Restore(syscall.Stdin, stdinState)
	stdoutState, err := terminal.MakeRaw(syscall.Stdout)
	if err != nil {
		return cfg{}, err
	}
	defer terminal.Restore(syscall.Stdout, stdoutState)
	t := struct {
		io.Reader
		io.Writer
	}{os.Stdin, os.Stdout}

	term := terminal.NewTerminal(t, "")

	msg := "Configure git-erickson for first time use.\nErickson server URL: "
	if _, err := term.Write([]byte(msg)); err != nil {
		return cfg{}, err
	}

	url, err := term.ReadLine()
	if err != nil {
		return cfg{}, err
	}

	cmd := exec.Command("git", "config", "--global", "erickson.url", string(url))
	if err := cmd.Run(); err != nil {
		return cfg{}, err
	}

	if _, err := term.Write([]byte("Erickson username: ")); err != nil {
		return cfg{}, err
	}

	username, err := term.ReadLine()
	if err != nil {
		return cfg{}, err
	}

	cmd = exec.Command("git", "config", "--global", "erickson.username", string(username))
	if err := cmd.Run(); err != nil {
		return cfg{}, err
	}

	return cfg{url: url, username: username}, nil
}

func terminalMode(c *serflash.Conn) {
	timeout := time.Duration(*idleFlag) * time.Second
	idleTimer := time.NewTimer(timeout)

	// FIXME still in line mode, so only complete lines will be shown
	go func() {
		for line := range c.Lines {
			idleTimer.Reset(timeout)
			fmt.Println(line)
		}
	}()

	// put stdin in raw mode
	oldState, err := terminal.MakeRaw(0)
	Check(err)
	defer terminal.Restore(0, oldState)

	// cleanup when program is terminated via a signal
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, os.Interrupt, syscall.SIGHUP, syscall.SIGTERM)
	go func() {
		sigMsg := <-sigChan
		terminal.Restore(0, oldState)
		log.Fatal(sigMsg)
	}()

	// cleanup when idle timer fires, and exit cleanly
	if *idleFlag > 0 {
		go func() {
			<-idleTimer.C
			terminal.Restore(0, oldState)
			fmt.Println("\nidle timeout")
			os.Exit(0)
		}()
	}

	// copy key presses to the serial port
	for {
		var b [1]byte
		n, _ := os.Stdin.Read(b[:])
		idleTimer.Reset(timeout)
		if n < 1 || b[0] == 0x1B { // ESC
			break
		}
		c.Write(b[:n])
	}

}

func suspend() {
	if oldTermState != nil {
		terminal.Restore(syscall.Stdin, oldTermState)
	}
	go resume()
	syscall.Kill(os.Getpid(), syscall.SIGTSTP)
}

func getPassword() ([]byte, error) {
	signals := make(chan os.Signal, 1)
	passwords := make(chan password)
	signal.Notify(signals, os.Interrupt, os.Kill)
	defer signal.Stop(signals)
	state, err := terminal.GetState(2)
	if err != nil {
		return nil, err
	}
	defer terminal.Restore(2, state)
	go func() {
		fmt.Fprintf(os.Stderr, "Password: ")
		defer fmt.Fprintf(os.Stderr, "\n")
		p, err := terminal.ReadPassword(2)
		passwords <- password{
			Password: p,
			Err:      err,
		}
		close(passwords)
	}()
	select {
	case <-signals:
		return nil, fmt.Errorf("Password entry cancelled")
	case password := <-passwords:
		return password.Password, password.Err
	}
}

// Close methods restores terminal, and send struct to Done chan.
func (s Shell) Close() {
	s.Write([]byte(fmt.Sprint("Bye!")))
	t.Restore(0, s.State)
	go func() {
		s.Done <- struct{}{}
	}()
}

func runAttached(c *cli.Context, app, ps, args, release string) (int, error) {
	fd := os.Stdin.Fd()

	var w, h int

	if terminal.IsTerminal(int(fd)) {
		stdinState, err := terminal.GetState(int(fd))
		if err != nil {
			return -1, err
		}

		defer terminal.Restore(int(fd), stdinState)

		w, h, err = terminal.GetSize(int(fd))
		if err != nil {
			return -1, err
		}
	}

	code, err := rackClient(c).RunProcessAttached(app, ps, args, release, h, w, os.Stdin, os.Stdout)
	if err != nil {
		return -1, err
	}

	return code, nil
}

func (i *Interactive) suspend() {
	if i.oldTermState != nil {
		terminal.Restore(syscall.Stdin, i.oldTermState)
	}
	go i.resume()
	syscall.Kill(os.Getpid(), syscall.SIGTSTP)
}

func (i *Interactive) exit() {
	if i.oldTermState != nil {
		terminal.Restore(syscall.Stdin, i.oldTermState)
	}
	fmt.Printf("\n")
	os.Exit(0)
}

// Close cleans up mongod and mongo processes and closes fd for the terminal
func (sh *QShell) Close() error {
	closeErr := sh.mongoStateHolder.close()
	if err := terminal.Restore(sh.stdinFd, sh.oldState); err != nil && closeErr == nil {
		closeErr = err
	}
	return closeErr
}

// Catch signals
func catchNotifications() {
	state, err := terminal.GetState(int(os.Stdin.Fd()))
	checkErr(err)

	// Deal with SIGINT
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, os.Interrupt)

	var timer time.Time
	go func() {
		for sig := range sigChan {
			// Prevent exiting on accidental signal send
			if time.Now().Sub(timer) < time.Second*signalTimeout {
				terminal.Restore(int(os.Stdin.Fd()), state)
				os.Exit(0)
			}

			fmt.Fprintln(os.Stderr, "")
			fmt.Fprintln(os.Stderr, "")
			fmt.Fprintln(os.Stderr, "")
			fmt.Fprintln(os.Stderr, sig, "signal caught!")
			fmt.Fprintf(os.Stderr, "Send signal again within %v seconds to exit\n", signalTimeout)
			fmt.Fprintln(os.Stderr, "")
			fmt.Fprintln(os.Stderr, "")
			fmt.Fprintln(os.Stderr, "")

			timer = time.Now()
		}
	}()
}

func cleanAndExit(oldState *terminal.State) {
	fmt.Println()
	if oldState != nil {
		terminal.Restore(0, oldState)
	}
	os.Exit(0)
}

// promptForPassword prompts the user for a password twice, returning
// the read bytes if they match, or an error.
// It turns out getting non-echo stdin is tricky and not portable at all.
// terminal seems a decent solution, although it does not work on windows.
func promptForPassword() ([]byte, error) {
	// Use a raw terminal.
	oldState, err := terminal.MakeRaw(0)
	if err != nil {
		return nil, err
	}
	defer func() {
		_ = terminal.Restore(0, oldState)
	}()

	fmt.Print("Enter password: ")
	one, err := terminal.ReadPassword(0)
	if err != nil {
		return nil, err
	}
	fmt.Print("\nConfirm password: ")
	two, err := terminal.ReadPassword(0)
	if err != nil {
		return nil, err
	}
	// Make sure stdout moves on to the next line.
	fmt.Print("\n")
	if !bytes.Equal(one, two) {
		return nil, util.Errorf("password mismatch")
	}
	return []byte(one), nil
}

func exit() {
	if oldTermState != nil {
		terminal.Restore(syscall.Stdin, oldTermState)
	}
	fmt.Printf("\n")
	os.Exit(0)
}

func getPassword() (string, error) {
	stdin := int(syscall.Stdin)
	initialTermState, err := terminal.GetState(stdin)
	if err != nil {
		return "", err
	}

	c := make(chan os.Signal)
	signal.Notify(c, os.Interrupt, os.Kill)
	go func() {
		s := <-c
		terminal.Restore(stdin, initialTermState)
		switch sig := s.(type) {
		case syscall.Signal:
			if int(sig) == 2 {
				fmt.Println("^C")
			}
		}
		os.Exit(1)
	}()

	passBytes, err := terminal.ReadPassword(stdin)
	if err != nil {
		return "", err
	}

	signal.Stop(c)
	fmt.Print("\n")
	return string(passBytes), nil
}

// promptConfirm prompts a user to confirm (or deny) something.
//
// True is returned iff the prompt is confirmed.
// Errors are reported to the log, and return false.
//
// Valid confirmations:
// 	y, yes, true, t, aye-aye
//
// Valid denials:
//	n, no, f, false
//
// Any other prompt response will return false, and issue a warning to the
// user.
func promptConfirm(msg string) bool {
	oldState, err := terminal.MakeRaw(0)
	if err != nil {
		log.Err("Could not get terminal: %s", err)
		return false
	}
	defer terminal.Restore(0, oldState)

	f := readerWriter(log.Stdin, log.Stdout)
	t := terminal.NewTerminal(f, msg+" (y/N) ")
	res, err := t.ReadLine()
	if err != nil {
		log.Err("Could not read line: %s", err)
		return false
	}
	res = strings.ToLower(res)
	switch res {
	case "yes", "y", "true", "t", "aye-aye":
		return true
	case "no", "n", "false", "f":
		return false
	}
	log.Warn("Did not understand answer %q, assuming No", res)
	return false
}

func connect(ip string, creds server.Credentials) error {
	config := &ssh.ClientConfig{
		User: creds.Username,
		Auth: []ssh.AuthMethod{
			ssh.Password(creds.Password),
		},
	}
	conn, err := ssh.Dial("tcp", fmt.Sprintf("%s:22", ip), config)
	if err != nil {
		return err
	}
	defer conn.Close()
	// Create a session
	session, err := conn.NewSession()
	defer session.Close()
	if err != nil {
		return err
	}

	fd := int(os.Stdin.Fd())
	oldState, err := terminal.MakeRaw(fd)
	if err != nil {
		return err
	}

	termWidth, termHeight, err := terminal.GetSize(fd)
	defer terminal.Restore(fd, oldState)
	if err != nil {
		return err
	}

	session.Stdout = os.Stdout
	session.Stderr = os.Stderr
	session.Stdin = os.Stdin

	modes := ssh.TerminalModes{
		ssh.ECHO:          1,     // disable echoing
		ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
		ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
	}
	// Request pseudo terminal
	if err := session.RequestPty("xterm-256color", termHeight, termWidth, modes); err != nil {
		return err
	}
	// Start remote shell
	if err := session.Shell(); err != nil {
		return err
	}

	if err := session.Wait(); err != nil {
		if reflect.TypeOf(err) == reflect.TypeOf(&ssh.ExitError{}) {
			return nil
		} else {
			return err
		}
	}

	return nil
}

func client(user, passwd, ip string) {
	config := &ssh.ClientConfig{
		User: user,
		Auth: []ssh.AuthMethod{
			ssh.Password(passwd),
		},
	}
	client, err := ssh.Dial("tcp", ip, config)
	if err != nil {
		fmt.Println("建立连接: ", err)
		return
	}
	defer client.Close()
	session, err := client.NewSession()
	if err != nil {
		fmt.Println("创建Session出错: ", err)
		return
	}
	defer session.Close()

	fd := int(os.Stdin.Fd())
	oldState, err := terminal.MakeRaw(fd)
	if err != nil {
		fmt.Println("创建文件描述符: ", err)
		return
	}

	session.Stdout = os.Stdout
	session.Stderr = os.Stderr
	session.Stdin = os.Stdin

	termWidth, termHeight, err := terminal.GetSize(fd)
	if err != nil {
		fmt.Println("获取窗口宽高: ", err)
		return
	}
	defer terminal.Restore(fd, oldState)

	modes := ssh.TerminalModes{
		ssh.ECHO:          1,
		ssh.TTY_OP_ISPEED: 14400,
		ssh.TTY_OP_OSPEED: 14400,
	}

	if err := session.RequestPty("xterm-256color", termHeight, termWidth, modes); err != nil {
		fmt.Println("创建终端出错: ", err)
		return
	}
	err = session.Shell()
	if err != nil {
		fmt.Println("执行Shell出错: ", err)
		return
	}
	err = session.Wait()
	if err != nil {
		fmt.Println("执行Wait出错: ", err)
		return
	}
}

func fatalf(format string, a ...interface{}) {
	if oldTermState != nil {
		terminal.Restore(syscall.Stdin, oldTermState)
	}
	fmt.Fprintf(os.Stderr, format, a...)
	fmt.Fprintf(os.Stderr, "\n")
	os.Exit(1)
}

func handleKey(line string, pos int, key rune) (newLine string, newPos int, ok bool) {
	if key == '\x03' {
		fmt.Println()
		terminal.Restore(0, regularState)
		os.Exit(0)
	}
	return "", 0, false
}