```console $ 04_02_validate --help clap [..] A simple to use, efficient, and full-featured Command Line Argument Parser Usage: 04_02_validate[EXE] Arguments: Network port to use Options: -h, --help Print help information -V, --version Print version information $ 04_02_validate 22 PORT = 22 $ 04_02_validate foobar ? failed error: Invalid value "foobar" for '': `foobar` isn't a port number For more information try --help $ 04_02_validate 0 ? failed error: Invalid value "0" for '': Port not in range 1-65535 For more information try --help ```