Netflix/go-expect

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

Go

475

63 commits

updated Jun 15, 2024

See the code

README

go-expect

Go Build Status GoDoc NetflixOSS Lifecycle

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)
}
automation
cli
expect

Significant stargazers

Abhinav Gupta

490 followers · starred Mar 2021

Iván Szkiba

53 followers · starred Dec 2023

Justin Nuß

23 followers · starred Oct 2020

John Eikenberry

66 followers · starred Aug 2025

Netflix/go-expect

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

Go

475

63 commits

updated Jun 15, 2024

See the code

README

go-expect

Go Build Status GoDoc NetflixOSS Lifecycle

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)
}
automation
cli
expect

Significant stargazers

Abhinav Gupta

490 followers · starred Mar 2021

Iván Szkiba

53 followers · starred Dec 2023

Justin Nuß

23 followers · starred Oct 2020

John Eikenberry

66 followers · starred Aug 2025