clap/examples/tutorial_derive/04_02_parse.md
Ed Page e1aafce431 test(tutorial): Ensure we actually test code
Biggest problem identified is that we are incorrectly setting the help
usage in `04_04_custom`
2022-08-08 14:05:08 -05:00

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$ 04_02_parse_derive --help
clap [..]
A simple to use, efficient, and full-featured Command Line Argument Parser

USAGE:
    04_02_parse_derive[EXE] <PORT>

ARGS:
    <PORT>    Network port to use

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

$ 04_02_parse_derive 22
PORT = 22

$ 04_02_parse_derive foobar
? failed
error: Invalid value "foobar" for '<PORT>': invalid digit found in string

For more information try --help

$ 04_02_parse_derive 0
? failed
error: Invalid value "0" for '<PORT>': 0 is not in 1..=65535

For more information try --help