clap/examples/tutorial_derive/03_04_subcommands.md

$ 03_04_subcommands_derive help
A simple to use, efficient, and full-featured Command Line Argument Parser

Usage:
    03_04_subcommands_derive[EXE] <COMMAND>

Commands:
    add     Adds files to myapp
    help    Print this message or the help of the given subcommand(s)

Options:
    -h, --help       Print help information
    -V, --version    Print version information

$ 03_04_subcommands_derive help add
Adds files to myapp

Usage:
    03_04_subcommands_derive[EXE] add [NAME]

Arguments:
    [NAME]    

Options:
    -h, --help       Print help information
    -V, --version    Print version information

$ 03_04_subcommands_derive add bob
'myapp add' was used, name is: Some("bob")

Because we used command: Commands instead of command: Option<Commands>:

$ 03_04_subcommands_derive
? failed
A simple to use, efficient, and full-featured Command Line Argument Parser

Usage:
    03_04_subcommands_derive[EXE] <COMMAND>

Commands:
    add     Adds files to myapp
    help    Print this message or the help of the given subcommand(s)

Options:
    -h, --help       Print help information
    -V, --version    Print version information

Because we added #[command(propagate_version = true)]:

$ 03_04_subcommands_derive --version
clap [..]

$ 03_04_subcommands_derive add --version
clap-add [..]