Читать книгу Practical Go - Amit Saha - Страница 41

In the following sections, you are going to improve the user interface of the greeter application in three ways:

 Remove the duplicate error messages

 Customize the help usage message

 Allow the user to enter their name via a positional argument

While implementing these improvements, you will learn how to create custom error values, customize a FlagSet object to print a customized usage message, and access positional arguments from your application.