ActiveCommand returns the name of the currently active command.

ParseFlags parses the app's flags and returns the parser, any extra arguments, and any error encountered.

ParseFlagsFromArgsOrDie is similar to ParseFlagsOrDie but allows control over the flags passed.

ParseFlagsOrDie parses the app's flags and dies if unsuccessful.

A ByteSize is used for flags that represent some quantity of bytes that can be passed as human-readable quantities (eg.

A CompletionHandler is the type of function that our flags library uses to handle completions.

A Duration is used for flags that represent a time duration; it's just a wrapper around time.Duration that implements the flags.Unmarshaler and encoding.TextUnmarshaler interfaces.