0257-CLAP-校验参数范围

环境

• Time 2022-12-03
• WSL-Ubuntu 22.04
• CLAP 4.0.29

前言

说明

参考：https://docs.rs/clap/latest/clap/index.html

目标

校验参数值的可选范围。

Cargo.toml

[package]
edition = "2021"
name = "game"
version = "1.0.0"

[dependencies]
clap = {version = "4", features = ["cargo"]}

main.rs

use clap::{command, value_parser, Arg};

fn main() {
    let matches = command!()
        .arg(
            Arg::new("age")
                .value_parser(value_parser!(u8).range(0..200))
                .help("年龄"),
        )
        .get_matches();

    if let Some(param) = matches.get_one::<u8>("age") {
        println!("set 的年龄是: {}", param);
    }
}

查看帮助

root@jiangbo12490:~/git/game# cargo run -- -h
   Compiling game v1.0.0 (/root/git/game)
    Finished dev [unoptimized + debuginfo] target(s) in 0.40s
     Running `target/debug/game -h`
Usage: game [age]

Arguments:
  [age]  年龄

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

使用

root@jiangbo12490:~/git/game# cargo run 255
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/game 255`
error: Invalid value '255' for '[age]': 255 is not in 0..200

For more information try '--help'
root@jiangbo12490:~/git/game# cargo run 25
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/game 25`
set 的年龄是: 25

总结

校验输入参数的范围。

附录