clap/examples/tutorial_derive/03_04_subcommands.md

$ 03_04_subcommands help
clap [..]
A simple to use, efficient, and full-featured Command Line Argument Parser

USAGE:
    03_04_subcommands[EXE] <SUBCOMMAND>

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

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

$ 03_04_subcommands help add
clap-add 3.2.14
Adds files to myapp

USAGE:
    03_04_subcommands[EXE] add [NAME]

ARGS:
    <NAME>    

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

$ 03_04_subcommands add bob
'myapp add' was used, name is: Some("bob")

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

$ 03_04_subcommands
? failed
clap [..]
A simple to use, efficient, and full-featured Command Line Argument Parser

USAGE:
    03_04_subcommands[EXE] <SUBCOMMAND>

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

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

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

$ 03_04_subcommands --version
clap [..]

$ 03_04_subcommands add --version
clap-add [..]