Make readme and rework the flags a little

main.go

@@ -19,19 +19,12 @@ type GlobalStats struct {
 	FailedFiles        int
 }
 
-type FileMode string
-
-const (
-	ModeRegex FileMode = "regex"
-	ModeXML   FileMode = "xml"
-	ModeJSON  FileMode = "json"
-)
-
 var stats GlobalStats
 var logger *log.Logger
 
 var (
-	fileModeFlag = flag.String("mode", "regex", "Processing mode: regex, xml, json")
+	jsonFlag = flag.Bool("json", false, "Process JSON files")
+	xmlFlag  = flag.Bool("xml", false, "Process XML files")
 )
 
 func init() {
@@ -67,7 +60,7 @@ func main() {
 	args := flag.Args()
 
 	if len(args) < 3 {
-		fmt.Fprintf(os.Stderr, "%s mode requires %d arguments minimum\n", *fileModeFlag, 3)
+		log.Printf("At least %d arguments are required", 3)
 		flag.Usage()
 		return
 	}
@@ -101,20 +94,19 @@ func main() {
 
 	// Create the processor based on mode
 	var proc processor.Processor
-	switch *fileModeFlag {
-	case "regex":
-		proc = &processor.RegexProcessor{}
-		logger.Printf("Starting regex modifier with pattern %q, expression %q on %d files",
+	switch {
+	case *xmlFlag:
+		proc = &processor.XMLProcessor{}
+		logger.Printf("Starting XML modifier with XPath %q, expression %q on %d files",
 			pattern, luaExpr, len(files))
-		// case "xml":
-		// 	proc = &processor.XMLProcessor{}
-		// 	pattern = *xpathFlag
-		// 	logger.Printf("Starting XML modifier with XPath %q, expression %q on %d files",
-		// 		pattern, luaExpr, len(files))
-	case "json":
+	case *jsonFlag:
 		proc = &processor.JSONProcessor{}
 		logger.Printf("Starting JSON modifier with JSONPath %q, expression %q on %d files",
 			pattern, luaExpr, len(files))
+	default:
+		proc = &processor.RegexProcessor{}
+		logger.Printf("Starting regex modifier with pattern %q, expression %q on %d files",
+			pattern, luaExpr, len(files))
 	}
 
 	var wg sync.WaitGroup