updated info when no args are supplied

main.go

@@ -14,6 +14,14 @@ import (
 	"strings"
 )
 
+func usageAndExit(msg string, code int) {
+	fmt.Fprintf(os.Stderr, "Fehler: %s\n\n", msg)
+	fmt.Fprintf(os.Stderr, "Beispiel:\n  go run ./main.go -wad MYMAP.wad -map MAP01 -info\n\n")
+	fmt.Fprintf(os.Stderr, "Verfügbare Flags:\n")
+	flag.PrintDefaults()
+	os.Exit(code)
+}
+
 func main() {
 	// Flags
 	wadPath := flag.String("wad", "", "Pfad zur WAD (required)")
@@ -37,12 +45,8 @@ func main() {
 
 	flag.Parse()
 
-	if *wadPath == "" {
-		fmt.Fprintf(os.Stderr, "Usage:\n")
-		fmt.Fprintf(os.Stderr, "  go run ./cmd/bspviz -wad MYMAP.wad -list\n")
-		fmt.Fprintf(os.Stderr, "  go run ./cmd/bspviz -wad MYMAP.wad -map MYMAP -info\n")
-		fmt.Fprintf(os.Stderr, "  go run ./cmd/bspviz -wad MYMAP.wad -map MYMAP -extract VERTEXES,LINEDEFS -out dumps/\n")
-		os.Exit(2)
+	if strings.TrimSpace(*wadPath) == "" {
+		usageAndExit("Flag -wad fehlt. Bitte Pfad zu einer Doom-kompatiblen WAD-Datei angeben.", 2)
 	}
 
 	w, err := wad.Open(*wadPath)