This is a package for create a deamon running background using binary commands, which will not use kill -9 to stop it(instead use kill -15).

Only avaliable on Linux and MacOS.

---

Example: Create a http server listening at 8080 with a background service nc listening at port 9999 and log to run.log. If the http server exists, the nc service exists too.

var flags = backgroundservice.Flags{
	BinPath: "nc",
	LogPath: "run.log",
	Args:    []string{"-l", "9999"},
}

func main() {
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, os.Interrupt, syscall.SIGTERM, syscall.SIGKILL)

	am := backgroundservice.New(backgroundservice.WithFlags(flags))
	go func() {
		err := am.Start()
		if err != nil {
			fmt.Println(err)
		}
	}()

	go func() {
		http.ListenAndServe(":8080", http.FileServer(http.Dir("/usr/share/doc")))
	}()

	<-stop
	err := am.Stop()
	if err != nil {
		fmt.Println(err)
	}
	os.Remove("run.log")

}

---

Methods:

	Stop() error  // Stop stop the background service, if stop failed will return error: ErrNoCmd, ErrIsNotRunning. This func call will not block. If call to this function returned error, the background service may still running
	Start() error // Start the log will be output to the LogPath defined by Flags. If the server start failed, error will be returned
	Wait() error  // Wait blocks until the background service exit. It return the error returned from cmd.Wait(). Calling to this function will block execution of Stop() and Start().
    New(opts ...Opt) Service     // New return an new background service. If no flags is specified, `nc` will be used default as BinPath and `run.log` will be used default LogPath, and Args will be `-l 9999`
    WithFlags(flags Flags) Opt // WithFlags set the Flags for the cmd. ** Panic ** This will panic if no flags.BinPath is specified. If no LogPath is specified, use run.log by default