1 files changed, 34 insertions, 5 deletions
diff --git a/cmd/tunneld/main.go b/cmd/tunneld/main.go
index 40d60d8..55783b6 100644
--- a/cmd/tunneld/main.go
+++ b/cmd/tunneld/main.go
@@ -25,6 +25,7 @@ var (
 	debugFlag   = flag.Bool("d", false, "debug: print time and source info")
 	forceFlag   = flag.Bool("f", false, "try start with force")
 	syslogFlag  = flag.Bool("s", false, "write log to syslog instead of stdout")
+	outputFlag  = flag.String("o", "", "write log to file instead of stdout")
 	configFlag  = flag.String("c", "", "path to configuration file")
 	socketFlag  = flag.String("S", "", "path to control socket")
 	versionFlag = flag.Bool("version", false, "print version and exit")
@@ -35,22 +36,45 @@ var BuildVersion string
 const trimSize = 32
 
 func initLog() {
-	var logFlags int
+	if *outputFlag != "" && *syslogFlag {
+		log.Fatal("bad usage: duplicate log write flag")
+	}
 
-	if *debugFlag {
-		logFlags |= log.Ldate | log.Ltime | log.Lshortfile
+	if *debugFlag  && *syslogFlag {
+		log.Fatal("bad usage: debug with syslog is out of sense")
 	}
 
-	log.SetFlags(logFlags)
+	if *outputFlag != "" {
+		const fileFlags = os.O_APPEND | os.O_CREATE | os.O_WRONLY
+
+		f, err := os.OpenFile(*outputFlag, fileFlags, 0644)
+		if err != nil {
+			log.Fatalf("log: %s", err)
+		}
+
+		log.SetOutput(f)
+	}
 
 	if *syslogFlag {
 		sysLog, err := syslog.New(syslog.LOG_INFO, "tunneld")
 		if err != nil {
-			log.Fatal(err)
+			log.Fatalf("log: %s", err)
 		}
 
 		log.SetOutput(sysLog)
 	}
+
+	var logFlags int
+
+	if *debugFlag {
+		logFlags |= log.Ldate | log.Ltime | log.Lshortfile
+	}
+
+	if *outputFlag != "" {
+		logFlags |= log.Ldate | log.Ltime
+	}
+
+	log.SetFlags(logFlags)
 }
 
 func sighandler(c chan os.Signal, s *server.Server) {
@@ -314,6 +338,7 @@ func deconfigure(s *server.Server) error {
 }
 
 func main() {
+	log.SetFlags(0)
 	flag.Parse()
 
 	if *versionFlag {
@@ -323,6 +348,10 @@ func main() {
 
 	initLog()
 
+	if flag.NArg() > 0 {
+		log.Fatal("bad usage: extra args")
+	}
+
 	socket := getSocketPath()
 	if *forceFlag {
 		if err := os.Remove(socket); err != nil {