ShellOutLineByLine.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"os"
	"os/exec"
	"strings"
)

func Run(args ...string) {
	args = strings.Split(strings.Join(args, " "), " ")
	c := exec.Command(args[0], args[1:]...)
	stderr, err := c.StderrPipe()
	if err != nil {
		log.Println(err)
		return
	}
	stdout, err := c.StdoutPipe()
	if err != nil {
		log.Println(err)
		return
	}
	if err := c.Start(); err != nil {
		log.Println(err)
		return
	}
	go Scan(stderr, os.Stderr)
	Scan(stdout, os.Stdout)
}

func Scan(in io.Reader, out io.Writer) {
	scanner := bufio.NewScanner(in)
	for scanner.Scan() {
		fmt.Fprintf(out, "%s\n", scanner.Text())
	}
}

func main() {
	Run("date")
	Run("pwd")
	Run("ping", "-V")
	Run("echo")
	Run("ping", "-c 3 www.google.com")
	Run("echo")
	Run("ping", "-c", "3", "www.yahoo.com")
	Run("ping -c 3 www.archlinux.com")
}