command-timeouts.go

package main

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"log"
	"os/exec"
	"time"
)

func main() {
	fmt.Println("Hello World!!")
	command := "ping -c 2 -i 1 8.8.8.8"
	out, err := CommandTimeoutWithTimer(command, 2*time.Second)
	fmt.Println("Output: ", out)
	if err != nil {
		fmt.Println("Error:", err.Error())
	}
}

//CommandTimeoutWithChannel command timeout using channel and goroutine
func CommandTimeoutWithChannel(command string, timeout time.Duration) (string, error) {
	cmd := exec.Command("/bin/bash", "-c", command)
	var out bytes.Buffer
	cmd.Stdout = &out

	err := cmd.Start()
	if err != nil {
		log.Printf("Error : %s", err.Error())
		return err.Error(), err
	}

	done := make(chan error)

	go func() { done <- cmd.Wait() }()

	timer := time.After(timeout)

	select {
	case <-timer:
		cmd.Process.Kill()
		fmt.Println("Command timed out")
		return "Command timed out", errors.New("Command Timeout")
	case err := <-done:
		if err != nil {
			return err.Error(), err
		}
		return out.String(), nil
	}
}

//CommandTimeoutWithContext command timeout with background context
func CommandTimeoutWithContext(command string, timeout time.Duration) (string, error) {
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	cmd := exec.CommandContext(ctx, "/bin/bash", "-c", command)
	out, err := cmd.CombinedOutput()

	if ctx.Err() == context.DeadlineExceeded {
		fmt.Println("Command timed out")
		return "Command timed out", errors.New("Command Timeout")
	}

	if err != nil {
		fmt.Println("Error : ", err.Error())
		return string(out), err
	}
	return string(out), nil
}

//CommandTimeoutWithTimer command timeout with timer
func CommandTimeoutWithTimer(command string, timeout time.Duration) (string, error) {
	cmd := exec.Command("/bin/bash", "-c", command)

	timer := time.AfterFunc(timeout, func() {
		cmd.Process.Kill()
	})

	out, err := cmd.CombinedOutput()

	isExpired := timer.Stop()
	if isExpired == false {
		fmt.Println("Command timed out")
		return "Command timed out", errors.New("Command Timeout")
	}

	if err != nil {
		log.Printf("Error : %s", err.Error())
		return string(out), err
	}

	return string(out), nil
}