nonblocking read from subprocess

main.go

package main

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

func main() {

	cmd := exec.Command("ping", "-c", "10", "www.google.com")
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		log.Fatal(err)
	}
	if err := cmd.Start(); err != nil {
		log.Fatal(err)
	}
	if raw, ok := stdout.(*os.File); !ok {
		log.Fatal(err)
	} else {
		syscall.SetNonblock(int(raw.Fd()), true)
	}
	go cmd.Wait()
	for {
		time.Sleep(time.Second)
		buffer := make([]byte, 1000)
		if read, err := stdout.Read(buffer); err == nil {
			log.Printf("%d read: %s", read, string(buffer[0:read-1]))
		} else {
			break
		}
	}
}