rust - 如何在带有 structopt crate 的子命令后使用 CLI 参数？

Question

例如，使用

运行我的应用程序

./app --foo=bar get

效果很好，但是

./app get --foo=bar

产生错误:

error: Found argument '--foo' which wasn't expected, or isn't valid in this context

USAGE:
    app --foo <foo> get

代码:

use structopt::*;

#[derive(Debug, StructOpt)]
#[structopt(name = "app")]
struct CliArgs {
    #[structopt(long)]
    foo: String,
    #[structopt(subcommand)]
    cmd: Cmd,
}

#[derive(Debug, StructOpt)]
enum Cmd {
    Get,
    Set,
}

fn main() {
    let args = CliArgs::from_args();
    println!("{:?}", args);
}

依赖关系:

structopt = { version = "0.3", features = [ "paw" ] }
paw = "1.0"

Answer 1

根据 issue 237 , 有一个 global 参数。没想到文档里没有提到。

global = true 效果很好:

use structopt::*;

#[derive(Debug, StructOpt)]
#[structopt(name = "cli")]
struct CliArgs {
    #[structopt(
        long,
        global = true,
        default_value = "")]
    foo: String,
    #[structopt(subcommand)]
    cmd: Cmd,
}

#[derive(Debug, StructOpt)]
enum Cmd {
    Get,
    Set,
}

fn main() {
    let args = CliArgs::from_args();
    println!("{:?}", args);
}

请注意，全局参数必须是可选的或具有默认值。