0258-CLAP-关联参数

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

设置两个参数相互关联。

Cargo.toml

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

[dependencies]
chrono = "0.4"
clap = {version = "4", features = ["cargo"]}

main.rs

use chrono::prelude::*;

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

fn main() {
    let matches = command!()
        .arg(
            Arg::new("age")
                .short('a')
                .value_parser(value_parser!(u8))
                .help("年龄"),
        )
        .arg(
            Arg::new("year")
                .short('y')
                .value_parser(value_parser!(i32))
                .help("出生年"),
        )
        .group(ArgGroup::new("born").required(true).args(["age", "year"]))
        .get_matches();

    if let Some(param) = matches.get_one::<u8>("age") {
        println!("年龄是：{}", param);
        let year = Local::now().year();
        println!("出生年是：{}", year - *param as i32);
    } else {
        let year = matches.get_one::<i32>("year").unwrap();
        println!("年龄是：{}", Local::now().year() - year);
        println!("出生年是：{}", year);
    }
}

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 0.50s
     Running `target/debug/game -h`
Usage: game <-a <age>|-y <year>>

Options:
  -a <age>       年龄
  -y <year>      出生年
  -h, --help     Print help information
  -V, --version  Print version information

使用

root@jiangbo12490:~/git/game# cargo run -- -a 44
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/game -a 44`
年龄是：44
出生年是：1978
root@jiangbo12490:~/git/game# cargo run -- -y 1978
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/game -y 1978`
年龄是：44
出生年是：1978
root@jiangbo12490:~/git/game# cargo run -- -y 1978 -a 44
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/game -y 1978 -a 44`
error: The argument '-y <year>' cannot be used with '-a <age>'

Usage: game <-a <age>|-y <year>>

For more information try '--help'

总结

设置两个参数相互关联。

附录