update version output

Makefile

@@ -4,9 +4,7 @@ CMD_DIR=$(shell pwd)/cmd
 VERSION=$(shell git describe --tags --long || echo "unknown version")
 BUILD_TIME=$(shell date -u)
 BUILD_TAGS='fakeDNS stats'
-GOBUILD=go build -ldflags '-X "github.com/xjasonlyu/tun2socks/constant.Version=$(VERSION)" \
-        -X "github.com/xjasonlyu/tun2socks/constant.BuildTime=$(BUILD_TIME)" \
-        -w -s'
+GOBUILD=go build -ldflags '-s -w -X "github.com/xjasonlyu/tun2socks/constant.Version=$(VERSION)"'
 
 all: build
 

cmd/main.go

@@ -7,6 +7,7 @@ import (
 	"net"
 	"os"
 	"os/signal"
+	"runtime"
 	"strings"
 	"syscall"
 	"time"
@@ -80,12 +81,18 @@ func init() {
 	args.UdpTimeout = flag.Duration("udpTimeout", 30*time.Second, "UDP session timeout")
 }
 
+func showVersion() {
+	version := strings.Split(C.Version, "-")
+	fmt.Printf("Go-tun2socks %s (%s)\n", version[0], version[1])
+	fmt.Printf("%s/%s, %s, %s\n", runtime.GOOS, runtime.GOARCH, runtime.Version(), version[2])
+}
+
 func main() {
 	// Parse args
 	flag.Parse()
 
 	if *args.Version {
-		fmt.Println("Go-tun2socks", C.Version, C.BuildTime)
+		showVersion()
 		os.Exit(0)
 	}
 

constant/version.go

@@ -1,6 +1,5 @@
 package constant
 
 var (
-	Version   = "unknown version"
-	BuildTime = "unknown time"
+	Version = "version-build-tag"
 )