Netflix / go-expect

an expect-like golang library to automate control of terminal or console based programs.

go-expect

Package expect provides an expect-like interface to automate control of applications. It is unlike expect in that it does not spawn or manage process lifecycle. This package only focuses on expecting output and sending input through it's pseudoterminal.

Usage

os.Exec example

package main

import (
	"log"
	"os"
	"os/exec"
	"time"

	expect "github.com/Netflix/go-expect"
)

func main() {
	c, err := expect.NewConsole(expect.WithStdout(os.Stdout))
	if err != nil {
		log.Fatal(err)
	}
	defer c.Close()

	cmd := exec.Command("vi")
	cmd.Stdin = c.Tty()
	cmd.Stdout = c.Tty()
	cmd.Stderr = c.Tty()

	go func() {
		c.ExpectEOF()
	}()

	err = cmd.Start()
	if err != nil {
		log.Fatal(err)
	}

	time.Sleep(time.Second)
	c.Send("iHello world\x1b")
	time.Sleep(time.Second)
	c.Send("dd")
	time.Sleep(time.Second)
	c.SendLine(":q!")

	err = cmd.Wait()
	if err != nil {
		log.Fatal(err)
	}
}

golang.org/x/crypto/ssh/terminal example

package main

import (
	"fmt"

	"golang.org/x/crypto/ssh/terminal"

	expect "github.com/Netflix/go-expect"
)

func getPassword(fd int) string {
	bytePassword, _ := terminal.ReadPassword(fd)

	return string(bytePassword)
}

func main() {
	c, _ := expect.NewConsole()

	defer c.Close()

	donec := make(chan struct{})
	go func() {
		defer close(donec)
		c.SendLine("hunter2")
	}()

	echoText := getPassword(int(c.Tty().Fd()))

	<-donec

	fmt.Printf("\nPassword from stdin: %s", echoText)
}