Golang tail.TailFile函數代碼示例

func readLog() {
	var seek = tail.SeekInfo{Offset: 0, Whence: 2}
	tailer, err := tail.TailFile(os.Args[1], tail.Config{
		Follow:   true,
		ReOpen:   true,
		Location: &seek,
	})
	if err != nil {
		log.Panicln(err)
	}

	re := regexp.MustCompile(`^(?P<ip>[\d\.]+) - - \[(?P<timestamp>.*)\] "(?P<verb>.*) (?P<query>.*) (?P<proto>.*)" (?P<status>\d+) (?P<bytes>\d+) "(?P<referer>.*)" "(?P<useragent>.*)"`)

	for line := range tailer.Lines {
		res := re.FindStringSubmatch(line.Text)
		ip := res[1]
		curtime := time.Now().Local()
		verb := res[3]
		query := res[4]
		proto := res[5]
		status, _ := strconv.Atoi(res[6])
		bytes, _ := strconv.ParseInt(res[7], 10, 64)
		referer := res[8]
		useragent := res[9]

		logline := RawLogEvent{ip, curtime, verb, query, proto, status, bytes, referer, useragent}

		rawlog_output <- logline
		logdump_output <- res[0] // Spraynard Kruger
	}
}

func main() {
	pub, err := nsq.NewProducer(*tHost, nsq.NewConfig())
	if err != nil {
		log.Fatal(err)
	}
	t, err := tail.TailFile(*tFile, tail.Config{Follow: true,
		//Location: &tail.SeekInfo{Offset: 0, Whence: os.SEEK_END}})
		Location: &tail.SeekInfo{Offset: 0, Whence: os.SEEK_CUR}})
	if err != nil {
		log.Fatal(err)
	}

	for line := range t.Lines {
		if *tTag != "" {
			for k, tag := range strings.Split(*tTag, "|") {
				var ks = []string{"pv", "click", "other"}
				if strings.Contains(line.Text, tag) {
					if *tDebug == "1" {
						fmt.Println(fmt.Println(line.Text))
					}
					pub.Publish("log", []byte(ks[k]+"\t"+line.Text))
				}
			}
		}
	}
}

func tailFile(ctx context.Context, file string, poll bool, dest *os.File) {
	defer wg.Done()
	t, err := tail.TailFile(file, tail.Config{
		Follow: true,
		ReOpen: true,
		Poll:   poll,
		Logger: tail.DiscardingLogger,
	})
	if err != nil {
		log.Fatalf("unable to tail %s: %s", "foo", err)
	}

	// main loop
	for {
		select {
		// if the channel is done, then exit the loop
		case <-ctx.Done():
			t.Stop()
			t.Cleanup()
			return
		// get the next log line and echo it out
		case line := <-t.Lines:
			if line != nil {
				fmt.Fprintln(dest, line.Text)
			}
		}
	}
}

func main() {
	if len(os.Args) != 3 {
		fmt.Println("Usage: canaryeye FILENAME COMMAND")
		os.Exit(1)
	}

	fn, cmd := os.Args[1], os.Args[2]

	m := map[string]int{}
	begin := time.Now()

	go canaryeye.Run(canaryeye.GetConfig(), &m, &begin, cmd)

	t, err := tail.TailFile(fn, *canaryeye.GetTailConfig())
	canaryeye.HandleError(err)

	r, _ := regexp.Compile("^([^ ]+)")

	for line := range t.Lines {
		matches := r.FindAllStringSubmatch(line.Text, -1)

		if len(matches) > 0 {
			m[matches[0][1]]++
		}
	}
}

func tailFile(path string) {
	t, err := tail.TailFile(path, tail.Config{
		Follow: true,
	})
	_ = t
	if err != nil {
		return
	}
	for {
		select {
		case line := <-t.Lines:
			logstream <- types.Message{
				FileName: t.Filename,
				Text:     line.Text,
			}
		case fn := <-RemoveTail:
			if path == fn {
				log.Info("remove file %s\n", fn)
				return
			} else {
				RemoveTail <- fn
			}
		}
	}
}

func follow_and_analyze(filename string, regexes []string, c chan incidentstore.Incident) {
	t, err := tail.TailFile(filename,
		tail.Config{
			Follow:   true,                                  // actually follow the logs
			ReOpen:   true,                                  // allow logs to be rotated
			Location: &tail.SeekInfo{Offset: 0, Whence: 2}}) // seek to end of file

	if err != nil {
		log.Fatal(err)
	}
	var compiledRegexes []regexp.Regexp
	for _, regex := range regexes {
		compiledRegex := regexp.MustCompile(regex)
		compiledRegexes = append(compiledRegexes, *compiledRegex)
	}

	for line := range t.Lines {
		// match each line against all regexes
		for _, regex := range compiledRegexes {
			result := regex.FindStringSubmatch(line.Text)
			if result != nil {
				ip := net.ParseIP(result[1])
				if ip != nil {
					c <- incidentstore.Incident{Filename: filename, Ip: ip, Time: time.Now(), Line: line.Text}

					// break here, this line matched on regex
					break
				}
			}
		}
	}

}

func (s *apiServer) Logs(r *types.LogsRequest, stream types.API_LogsServer) error {
	state, err := s.getState(r.Id)
	if err != nil {
		return err
	}

	// if the job has completed or failed then we cannot follow
	follow := r.Follow
	if string(state) == string(jobFailed) || string(state) == string(jobCompleted) {
		follow = false
	}

	stdout := filepath.Join(s.StateDir, string(jobIDByte(r.Id)), "stdout")
	t, err := tail.TailFile(stdout, tail.Config{
		Follow:    follow,
		MustExist: true,
	})
	if err != nil {
		return fmt.Errorf("Tail file %s failed: %v", stdout, err)
	}

	for line := range t.Lines {
		if err := stream.Send(&types.Log{Log: line.Text}); err != nil {
			return fmt.Errorf("Sending log to stream failed: %v", err)
		}
	}

	return nil
}

func main() {
	ConfigBytes, err := ioutil.ReadFile(*ConfigFile)
	if err != nil {
		log.Fatalf("Error reading config file %s\n", err)
	}
	err = json.Unmarshal(ConfigBytes, &Config)
	if err != nil {
		log.Fatalf("Error parsing config file %s\n", err)
	}

	for _, endpointConfig := range Config.Endpoints {
		log.Printf("Starting up %s handler", endpointConfig.Driver)
		endpointConfig.e = endpointDrivers[endpointConfig.Driver](endpointConfig.Options)
		endpointConfig.e.HandleMessage(Message)
		endpointConfig.e.Run()
	}

	for name, logConfig := range Config.Logs {
		go func(name string, logConfig *Log) {
			logfile, err := tail.TailFile(logConfig.File, tail.Config{Location: &tail.SeekInfo{Whence: os.SEEK_END}, Follow: true, ReOpen: true})

			if err != nil {
				log.Printf("Error tailing file: %s", err)
			}
			var filter *regexp.Regexp
			if logConfig.Regex != "" {
				var err error
				filter, err = regexp.Compile(logConfig.Regex)
				if err != nil {
					log.Printf("Error compiling regex: %s", err)
				}
			}
			for line := range logfile.Lines {
				if line.Err != nil {
					log.Printf("Error tailing file: %s", line.Err)
				}
				if filter == nil || filter.MatchString(line.Text) {
					logConfig.lines = append(logConfig.lines, line)
					if len(logConfig.lines) > logConfig.Keep {
						logConfig.lines = logConfig.lines[len(logConfig.lines)-logConfig.Keep:]
					}
					/*if logConfig.Live {
						for _, channel := range logConfig.Channels {
							c.Privmsg(channel, line.Text)
						}
					}*/
				}
			}

		}(name, logConfig)
	}
	for _, monitorConfig := range Config.Monitors {
		monitorConfig.monitor = monitorDrivers[monitorConfig.Driver](monitorConfig.Options)
		monitorConfig.track = newMonitorTrack()
		monitorConfig.track.Start(monitorConfig.monitor)
	}
	quit := make(chan bool)
	<-quit
}

func (recv ChromebusRecordTailReceiver) open() {
	var err error
	recv.t, err = tail.TailFile(Events, tail.Config{Follow: true})
	if err != nil {
		log.Fatal(err)
	}
	recv.opened = true
}

// Creates a Watcher around a watched file.
func WatchLog(watched string) Watcher {
	tail, err := tail.TailFile(watched, tail.Config{Follow: true, ReOpen: true})
	if err != nil {
		log.WithError(err).Fatal()
		panic(err)
	}
	return Watcher{Tail: tail}
}

func (i *Tail) createTailReader(config tail.Config) {
	tail, err := tail.TailFile(i.file, config)
	if err != nil {
		Critical("tail %s: %v", i.file, err)
	}

	i.tail = tail
}

// printLogs streams the content of a file on the standard output.
// When it stops working, it sends a message in the stopNotifier channel.
func (d *Daemon) printLogs(filename string, stopNotifier chan<- string) {
	t, _ := tail.TailFile(filename, tail.Config{Follow: true})

	for line := range t.Lines {
		fmt.Println(line.Text)
	}

	stopNotifier <- fmt.Sprintf("could not stream logs from `%s`", filename)
}

// OpenLogfile opens a logfile and passes back a *tail.Tail pointer.
func OpenLogfile(logfile string) *tail.Tail {
	t, err := tail.TailFile(logfile, tail.Config{
		Location: &tail.SeekInfo{Whence: os.SEEK_END},
		ReOpen:   true,
		Follow:   true})
	if err != nil {
		Log("There was an error opening the file.", "info")
	}
	return t
}

func (this *TailsInput) Tailer(f string) error {
	var seek int
	var offset int64
	var err error
	pointfile := fmt.Sprintf("%s/%d", this.config.JournalDirectory, hash(f))
	if offset, err = readPoint(pointfile); err != nil {
		seek = os.SEEK_END
	} else {
		seek = os.SEEK_SET
	}
	t, err := tail.TailFile(f, tail.Config{
		Poll:      true,
		ReOpen:    true,
		Follow:    true,
		MustExist: false,
		Location:  &tail.SeekInfo{int64(offset), seek},
	})
	if err != nil {
		return err
	}

	tick := time.NewTicker(time.Second * time.Duration(3))
	count := 0

	for {
		select {
		case <-tick.C:
			{
				if count > 0 {
					offset, err := t.Tell()
					if err != nil {
						log.Println("Tell return error: ", err)
						continue
					}
					if err = writePoint(pointfile, offset); err != nil {
						return err
					}
					count = 0
				}
			}
		case line := <-t.Lines:
			{
				pack := <-this.runner.InChan()
				pack.MsgBytes = []byte(line.Text)
				pack.Msg.Tag = this.common.Tag
				pack.Msg.Timestamp = time.Now().Unix()
				count++
				this.runner.RouterChan() <- pack
			}
		}
	}
	err = t.Wait()
	return err
}

// shows all new lines in cconsole.log
func tailCConsoleLog(inst string) {
	folder := getInstanceFolder(inst)
	endLocation := tail.SeekInfo{Offset: 0, Whence: os.SEEK_END}
	if t, err := tail.TailFile(folder+"/mgr/cconsole.log", tail.Config{Follow: true, Location: &endLocation}); err != nil {
		log.Printf("Error while getting content for cconsole.log\n")
		log.Printf("ERR: %s.\n", err)
	} else {
		for line := range t.Lines {
			fmt.Println(line.Text)
		}
	}
}