Golang handling os.signal with goroutines

Learning goroutines and practising with `os.Signal`

This is the small snippet of golang codes that showing how goroutines work perfectly.

package main

import (

"fmt"

"os"

"os/signal"

"syscall"

"time"

)

func signalHandler(signal os.Signal) {

switch signal {

case syscall.SIGHUP:

fmt.Println("Signal:", signal.String())

case syscall.SIGINT:

fmt.Println("Signal:", signal.String())

case syscall.SIGTERM:

fmt.Println("Signal:", signal.String())

case syscall.SIGQUIT:

fmt.Println("Signal:", signal.String())

default:

fmt.Println("Unhandled/unknown signal")

}

}

func keepDoingStuffs() {

for {

fmt.Printf("Starting job...")

time.Sleep(time.Second * 5)

fmt.Println("completed.")

}

}

func printNumbers() {

for {

time.Sleep(time.Second * 1)

fmt.Printf(".")

}

}

func trapTimeout(done chan bool) {

for {

select {

case <-time.After(time.Second * 20):

fmt.Println("Timeout.")

done <- true

case <-done:

return

}

}

}

func trapSignal(done chan bool) {

sigc := make(chan os.Signal, 1)

defer close(sigc)

signal.Notify(sigc, syscall.SIGINT, syscall.SIGHUP, syscall.SIGTERM, syscall.SIGQUIT)

for {

select {

case s := <-sigc:

signalHandler(s)

done <- true

case <-done:

return

}

}

}

func main() {

done := make(chan bool)

defer close(done)

go trapSignal(done)

go trapTimeout(done)

go keepDoingStuffs()

go printNumbers()

if <-done {

fmt.Println("Exit gracefully.")

return

}

}