golang wait for x time channel (no wait groups)

golangWaitXTimeChannelNoWaitGroups.go

package main

import (
	"fmt"
	"math/rand"
	"time"
)

func zzz(tme int) {
	r := rand.Intn(10)
	t := time.Duration(r) * time.Microsecond
	fmt.Sprintln("Sleeping for %d", t)
	time.Sleep(t)
}

func simulateJob(index int, item string) string {
	rand.Seed(time.Now().UnixNano())
	sleepTime := rand.Intn(10-3) + 3
	zzz(sleepTime)
	return fmt.Sprintf("%d. %s", index, item)
}

func work(index int, item string, c chan string) {
	c <- simulateJob(index, item)
}

func main() {
	c := make(chan string)
	life := 200
	defer close(c)

	letters := []string{"a", "b", "c", "d", "e", "f", "g"}
	for index, item := range letters {
		go work(index, item, c)
	}
	for {
		select {
		case s := <-c:
			fmt.Printf("out : %+v\n", s)
		default:
			time.Sleep(50 * time.Millisecond)
			if life--; life == 0 {
				return
			}
		}
	}
}