update logging

main.go

@@ -328,20 +328,22 @@ func main() {
 	// Load the JSON data from file
 	file, err := os.Open(*inputFile)
 	if err != nil {
-		log.Fatalf("Failed to open input.json: %v", err)
+		fmt.Printf("Failed to open input.json: %v", err)
+		os.Exit(1)
 	}
 	defer file.Close()
 
 	byteValue, err := io.ReadAll(file)
 	if err != nil {
-		log.Fatalf("Failed to read input json: %v", err)
+		fmt.Printf("Failed to read input json: %v", err)
+		os.Exit(1)
 	}
 
 	// Detect encoding and convert to UTF-8 if necessary
 	utf8Data, err := ensureUTF8(byteValue)
 	if err != nil {
 		fmt.Printf("Error ensuring UTF-8 encoding: %v\n", err)
-		return
+		os.Exit(1)
 	}
 
 	if err := json.Unmarshal(utf8Data, &data); err != nil {
@@ -360,6 +362,8 @@ func main() {
 		fmt.Printf("Error saving excel workbook: %s\n", err)
 		os.Exit(1)
 	}
+
+	os.Exit(0)
 }
 
 // parseDate parses a date string like "January-2006" into a time.Time object