Powerful Command-Line Applications in Go

Handling Multiple Command-Line Options

As you’ve seen while implementing the initial version of your command-line interface, using the os.Args variable isn’t a flexible way of handling command-line arguments. Let’s improve the tool by using the flag package to parse and handle multiple command-line options.

The flag package enables you to define command-line flags of specific types such as int or string so you don’t need to convert them manually.

This version of the tool will accept three command-line arguments:

1. -list: A Boolean flag. When used, the tool will list all to-do items.

2. -task: A string flag. When used, the tool will include the string argument as a new to do item in the list.

3. -complete: An integer flag. When used, the tool will mark ...