This is a copy of the flag package adapted to work with environment variables.

Use this package to:

• Define different environment variables, their default value, and description.
• Define different environments, e.g. one set of environment variables for each subcommand.
• Get a description of the environment variables defined using the -h/--help command line flag parsing behavior.
• Get a description of the environment variables defined by setting HELP or H.
• Add support for your types to be used as environment variables.