adding version to code

main.go

@@ -8,14 +8,31 @@ import (
     "strings"
 )
 
-func main() {
-    display := os.Getenv("DISPLAY")
-    proxySocket := "/tmp/.X11-unix/X5"
+const version = "0.1"
 
-    overrideDisplay := flag.String("display", "", "Override DISPLAY")
-    overrideSocket := flag.String("proxy-socket", proxySocket, "Proxy socket path")
+var (
+    overrideDisplay = flag.String("display", "", "Override DISPLAY")
+    overrideSocket  = flag.String("proxy-socket", "/tmp/.X11-unix/X5", "Proxy socket path")
+    showVersion     = flag.Bool("version", false, "Show version and exit")
+)
+
+func init() {
+    flag.Usage = func() {
+        fmt.Fprintf(os.Stderr, "Usage of %s:\n\n", os.Args[0])
+        flag.PrintDefaults()
+    }
+}
+
+func main() {
     flag.Parse()
 
+    if *showVersion {
+        fmt.Printf("X11Proxy version %s\n", version)
+        return
+    }
+    fmt.Printf("version %s\n", version)
+
+    display := os.Getenv("DISPLAY")
     if *overrideDisplay != "" {
         display = *overrideDisplay
     }
@@ -41,7 +58,6 @@ func hexDump(buf []byte) string {
     for i := 0; i < len(buf); i += 16 {
         line := fmt.Sprintf("%08x  ", i)
 
-        // Hex section
         for j := 0; j < 16; j++ {
             if i+j < len(buf) {
                 line += fmt.Sprintf("%02x ", buf[i+j])
@@ -49,13 +65,12 @@ func hexDump(buf []byte) string {
                 line += "   "
             }
             if j == 7 {
-                line += " " // extra space in middle
+                line += " "
             }
         }
 
         line += " |"
 
-        // ASCII section
         for j := 0; j < 16 && i+j < len(buf); j++ {
             b := buf[i+j]
             if b >= 32 && b <= 126 {