clap/examples/tutorial_derive/04_02_parse.md
Ed Page 9b23a09f7a fix(help): Don't rely on ALL CAPS for headers
I see them fulfilling two roles
- A form of bolding
- As a callback to their placeholder in usage

However, it is a bit of an unpolished look and no other CLI seems to do
it.  This looks a bit more proefessional.  We have colored help for
formatting and I think the sections relation to usage will be clear
enough.
2022-08-26 10:21:18 -05:00

626 B

$ 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>

Arguments:
    <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