service: add example to comment doc.

service.go

@@ -10,6 +10,105 @@
 // despite the substantial differences.
 // It also can be used to detect how a program is called, from an interactive
 // terminal or from a service manager.
+/*
+	// Simple service that only works by printing a log message every few seconds.
+	package main
+
+	import (
+		"log"
+		"os"
+		"time"
+
+		"bitbucket.org/kardianos/service2beta"
+	)
+
+	var logger service.Logger
+
+	// Program structures.
+	//  Define Start and Stop methods.
+	type program struct {
+		exit chan struct{}
+	}
+
+	func (p *program) Start(s service.Service) error {
+		if service.Local.Interactive() {
+			logger.Info("Running in terminal.")
+		} else {
+			logger.Info("Running under service manager.")
+		}
+		p.exit = make(chan struct{})
+
+		// Start should not block. Do the actual work async.
+		go p.run()
+		return nil
+	}
+	func (p *program) run() error {
+		logger.Infof("I'm running %v.", service.Local)
+		ticker := time.NewTicker(2 * time.Second)
+		for {
+			select {
+			case tm := <-ticker.C:
+				logger.Infof("Still running at %v...", tm)
+			case <-p.exit:
+				ticker.Stop()
+				return nil
+			}
+		}
+		return nil
+	}
+	func (p *program) Stop(s service.Service) error {
+		// Any work in Stop should be quick, usually a few seconds at most.
+		logger.Info("I'm Stopping!")
+		close(p.exit)
+		return nil
+	}
+
+	// Service setup.
+	//   Define service config.
+	//   Create the service.
+	//   Setup the logger.
+	//   Handle service controls (optional).
+	//   Run the service.
+	func main() {
+		svcConfig := &service.Config{
+			Name:        "GoServiceTest",
+			DisplayName: "Go Service Test",
+			Description: "This is a test Go service.",
+		}
+
+		prg := &program{}
+		s, err := service.New(prg, svcConfig)
+		if err != nil {
+			log.Fatal(err)
+		}
+		errs := make(chan error, 5)
+		logger, err = s.Logger(errs)
+		if err != nil {
+			log.Fatal(err)
+		}
+		go func() {
+			for {
+				err := <-errs
+				if err != nil {
+					log.Print(err)
+				}
+			}
+		}()
+
+		if len(os.Args) > 1 {
+			err := service.Control(s, os.Args[1])
+			if err != nil {
+				log.Printf("Valid actions: %q\n", service.ControlAction)
+				log.Fatal(err)
+			}
+			return
+		}
+		err = s.Run()
+		if err != nil {
+			logger.Error(err)
+		}
+	}
+*/
 package service
 
 import (