Parse the command line using the default Shell.

Register this command on the default Shell.

Default is a single global instance of Shell used for command-line argument parsing.

ErrMissingCommand indicates that a subcommand is needed but was not seen in the arguments.

Result is the result of parsing the arguments given to a command.

Shell is a collection of commands, identified by the package that defines them.

DescriptionGetter is used to give a short description of the command when showing a list of subcommands.

FlagParser is implemented by commands that wish to process their arguments before subcommand traversal continues.

FlagSetter is used to recognize a flag.FlagSet (even when embedded in a struct).

Overviewer is used to give an overview explanation of the command.

Runner is used as a marker interface to distinguish commands that are valid by themselves, even when they have subcommands.

SynopsesGetter is used to give a list of synopses snippets, short summaries of the arguments that can be passed in.

VisiterAll is an interface that lets commands report what "-foo" style flags they support.

Description contains a short description of the command it is embedded in.

Overview contains one or more paragraphs of text giving an overview of the command.

Synopses contains a list of synopses snippets, short summaries of the arguments that can be passed in.

Synopsis contains a synopsis snippet, a short summary of the arguments that can be passed in.