Handle OS signal on golang

main.go

package main

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"
)

// ExitCode is process exit code to os
type ExitCode int

// Process exsit codes
const (
	Error    ExitCode = 1
	Critical ExitCode = 128
)

func criticalExitCode(s syscall.Signal) ExitCode {
	r := ExitCode(int(Critical) + int(s))

	return r
}

func main() {

	signalc := make(chan os.Signal, 1)
	signal.Notify(signalc,
		syscall.SIGHUP,
		syscall.SIGINT,
		syscall.SIGTERM,
		syscall.SIGQUIT)

	exitc := make(chan ExitCode)
	go func() {
		for {
			s := <-signalc
			switch s {
			// kill -SIGHUP XXXX
			case syscall.SIGHUP:
				fmt.Println("SIGHUP")
				exitc <- criticalExitCode(syscall.SIGHUP)
			// kill -SIGINT XXXX or Ctrl+c
			case syscall.SIGINT:
				fmt.Println("SIGINT")
				exitc <- criticalExitCode(syscall.SIGINT)
			// kill -SIGTERM XXXX
			case syscall.SIGTERM:
				fmt.Println("SIGTERM")
				exitc <- criticalExitCode(syscall.SIGTERM)
			// kill -SIGQUIT XXXX
			case syscall.SIGQUIT:
				fmt.Println("SIGQUIT")
				exitc <- criticalExitCode(syscall.SIGQUIT)
			default:
				fmt.Println("UNKNOWN SIGNAL")
				exitc <- Error
			}
		}
	}()

	code := <-exitc
	os.Exit(int(code))
}