Option Help

It’s common in many CLI frameworks for every command having options --help and -h to print out command help. Spring Shell has a built-in help command.

Extensions of AbstractCommand will get help functionality (ie handling options --help and -h), which if present in a given command will automatically short circuit command execution into an existing help command regardless what other command-line options are typed.

Both ways of asking for the help of a command, <command> --help (or <command> -h) and help <command>, render the same message. It reports the name and the description of the command, its synopsis, and its options, arguments and aliases, if any.

The help attribute of a command is reported as the DESCRIPTION section of that message and is omitted when the command does not define one. Unlike description, which is a one liner shown in the list of available commands, help is meant to be a longer explanation of what the command does.