用 Rust 实现 HTTPie：一个现代 CLI 工具的构建过程
命令行工具（CLI）是开发者工具箱中不可或缺的一部分。在众多用于 HTTP 测试的工具中，cURL 功能强大，而 HTTPie 则以其出色的用户体验和易用性备受青睐。后者正是一个优秀的现代 CLI 工具范例。
本文将完整记录使用 Rust 语言构建一个类 HTTPie 工具的全过程。我们将从功能需求分析出发，逐步探讨如何利用 Rust 的生态系统来处理命令行参数解析、执行异步网络请求，以及如何对响应结果进行格式化与高亮输出，最终呈现一个功能完备的 CLI 应用。
需求分析与项目初始化
实现 HTTPie 为例，看看用 Rust 怎么做 CLI。HTTPie 是用 Python 开发的，一个类似 cURL 但对用户更加友善的命令行工具，它可以帮助我们更好地诊断 HTTP 服务。
功能分析要做一个 HTTPie 这样的工具，我们先梳理一下要实现哪些主要功能：
- 首先是做命令行解析，处理子命令和各种参数，验证用户的输入，并且将这些输入转换成我们内部能理解的参数；
- 之后根据解析好的参数，发送一个 HTTP 请求，获得响应；
- 最后用对用户友好的方式输出响应。
创建项目
bash
~ via 🅒 base
➜ cd Code/rust
~/Code/rust via 🅒 base
➜ cargo new httpie
Created binary (application) `httpie` package
~/Code/rust via 🅒 base
➜ cd httpie
httpie on master [?] via 🦀 1.88.0 via 🅒 base
➜ c
httpie on master [?] via 🦀 1.88.0 via 🅒 base
➜Cargo.toml
toml
[package]
name = "httpie"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
anyhow = "1.0.71" # 错误处理
clap = { version = "4.3.9", features = ["derive"] }
colored = "2.0.0" # 命令终端多彩显示
jsonxf = "1.1.1" # JSON pretty print 格式化
mime = "0.3.17" # 处理 mime 类型
reqwest = { version = "0.11.18", features = ["json"] } # HTTP 客户端
tokio = { version = "1.29.0", features = ["full"] } # 异步处理库main.rs
rust
use clap::Parser;
// 定义 HTTPie 的 CLI 的主入口，它包含若干个子命令
// 下面 /// 的注释是文档，clap 会将其作为 CLI 的帮助
/// A naive httpie implementation with Rust, can you imagine how easy it is?
#[derive(Parser, Debug)]
#[clap(version = "1.0", author = "Tyr Chen <tyr@chen.com>")]
struct Opts {
#[clap(subcommand)]
subcmd: SubCommand,
}
// 子命令分别对应不同的 HTTP 方法，目前只支持 get / post
#[derive(Parser, Debug)]
enum SubCommand {
Get(Get),
Post(Post),
// 我们暂且不支持其它 HTTP 方法
}
// get 子命令
/// feed get with an url and we will retrieve the response for you
#[derive(Parser, Debug)]
struct Get {
/// HTTP 请求的 URL
url: String,
}
// post 子命令。需要输入一个 URL，和若干个可选的 key=value，用于提供 json body
/// feed post with an url and optional key=value pairs. We will post the data
/// as JSON, and retrieve the response for you
#[derive(Parser, Debug)]
struct Post {
/// HTTP 请求的 URL
url: String,
/// HTTP 请求的 body
body: Vec<String>,
}
fn main() {
let opts: Opts = Opts::parse();
println!("{:?}", opts);
}运行
bash
httpie on master [?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 8.7s
➜ cargo build --quiet && target/debug/httpie post httpbin.org/post a=1 b=2
Opts { subcmd: Post(Post { url: "httpbin.org/post", body: ["a=1", "b=2"] }) }
httpie on master [?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ cargo build --quiet && target/debug/httpie post a=1 b=2
Opts { subcmd: Post(Post { url: "a=1", body: ["b=2"] }) }
httpie on master [?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 2.9s
➜ Git 代码提交
bash
ttpie on master [?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ echo "# httpie" >> README.md
httpie on master [?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ git add .
httpie on master [+] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ git commit -m "first commit"
[master（根提交） fe158bb] first commit
5 files changed, 1434 insertions(+)
create mode 100644 .gitignore
create mode 100644 Cargo.lock
create mode 100644 Cargo.toml
create mode 100644 README.md
create mode 100644 src/main.rs
httpie on master is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ git branch -M main
httpie on main is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ git remote add origin git@github.com:qiaopengjun5162/httpie.git
httpie on main is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ git push -u origin main
枚举对象中: 8, 完成.
对象计数中: 100% (8/8), 完成.
使用 12 个线程进行压缩
压缩对象中: 100% (5/5), 完成.
写入对象中: 100% (8/8), 10.50 KiB | 5.25 MiB/s, 完成.
总共 8（差异 0），复用 0（差异 0），包复用 0
To github.com:qiaopengjun5162/httpie.git
* [new branch] main -> main
分支 'main' 设置为跟踪 'origin/main'。
httpie on main is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 4.3s
➜完整代码
项目目录
bash
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ tree -a -I "target|.git"
.
├── .gitignore
├── Cargo.lock
├── Cargo.toml
├── README.md
└── src
└── main.rs
2 directories, 5 files
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ main.rs
rust
use anyhow::{anyhow, Result};
use clap::Parser;
use colored::Colorize;
use mime::Mime;
use reqwest::{header, Client, Response, Url};
use std::{collections::HashMap, str::FromStr};
use syntect::{
easy::HighlightLines,
highlighting::{Style, ThemeSet},
parsing::SyntaxSet,
util::{as_24_bit_terminal_escaped, LinesWithEndings},
};
// 以下部分用于处理 CLI
// 定义 HTTPie 的 CLI 的主入口，它包含若干个子命令
// 下面 /// 的注释是文档，clap 会将其作为 CLI 的帮助
/// A naive httpie implementation with Rust, can you imagine how easy it is?
/// 一个用 Rust 实现的简易版 httpie，简单到你无法想象
#[derive(Parser, Debug)]
#[clap(version = "1.0", author = "Tyr Chen <tyr@chen.com>")]
struct Opts {
#[clap(subcommand)]
subcmd: SubCommand,
}
// 子命令分别对应不同的 HTTP 方法，目前只支持 get / post
#[derive(Parser, Debug)]
enum SubCommand {
Get(Get),
Post(Post),
// 我们暂且不支持其它 HTTP 方法
}
// get 子命令
/// feed get with an url and we will retrieve the response for you
/// 发送一个 GET 请求，获取服务端响应
#[derive(Parser, Debug)]
struct Get {
/// HTTP 请求的 URL
#[arg(value_parser=parse_url)]
url: String,
}
// post 子命令。需要输入一个 URL，和若干个可选的 key=value，用于提供 json body
/// feed post with an url and optional key=value pairs. We will post the data
/// as JSON, and retrieve the response for you
#[derive(Parser, Debug)]
struct Post {
/// HTTP 请求的 URL
#[arg(value_parser=parse_url)]
url: String,
/// HTTP 请求的 body
#[arg(value_parser=parse_kv_pair)]
body: Vec<KvPair>,
}
/// 命令行中的 key=value 可以通过 parse_kv_pair 解析成 KvPair 结构
#[derive(Debug, Clone, PartialEq)]
struct KvPair {
k: String,
v: String,
}
/// 当我们实现 FromStr trait 后，可以用 str.parse() 方法将字符串解析成 KvPair
impl FromStr for KvPair {
type Err = anyhow::Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
// 使用 = 进行 split，这会得到一个迭代器
let mut split = s.split("=");
let err = || anyhow!(format!("Failed to parse {}", s));
Ok(Self {
// 从迭代器中取第一个结果作为 key，迭代器返回 Some(T)/None
// 我们将其转换成 Ok(T)/Err(E)，然后用 ? 处理错误
k: (split.next().ok_or_else(err)?).to_string(),
// 从迭代器中取第二个结果作为 value
v: (split.next().ok_or_else(err)?).to_string(),
})
}
}
/// 因为我们为 KvPair 实现了 FromStr，这里可以直接 s.parse() 得到 KvPair
fn parse_kv_pair(s: &str) -> Result<KvPair> {
Ok(s.parse()?)
}
fn parse_url(s: &str) -> Result<String> {
// 这里我们仅仅检查一下 URL 是否合法
let _url: Url = s.parse()?;
Ok(s.into())
}
/// 处理 get 子命令
async fn get(client: Client, args: &Get) -> Result<()> {
let resp = client.get(&args.url).send().await?;
Ok(print_resp(resp).await?)
}
/// 处理 post 子命令
async fn post(client: Client, args: &Post) -> Result<()> {
let mut body = HashMap::new();
for pair in args.body.iter() {
body.insert(&pair.k, &pair.v);
}
let resp = client.post(&args.url).json(&body).send().await?;
Ok(print_resp(resp).await?)
}
// 打印服务器版本号 + 状态码
fn print_status(resp: &Response) {
let status = format!("{:?} {}", resp.version(), resp.status()).blue();
println!("{}\n", status);
}
// 打印服务器返回的 HTTP header
fn print_headers(resp: &Response) {
for (name, value) in resp.headers() {
println!("{}: {:?}", name.to_string().green(), value);
}
println!();
}
/// 打印服务器返回的 HTTP body
fn print_body(m: Option<Mime>, body: &str) {
match m {
// 对于 "application/json" 我们 pretty print
Some(v) if v == mime::APPLICATION_JSON => print_syntect(body, "json"),
Some(v) if v == mime::TEXT_HTML => print_syntect(body, "html"),
// 其它 mime type，我们就直接输出
_ => println!("{}", body),
}
}
/// 打印整个响应
async fn print_resp(resp: Response) -> Result<()> {
print_status(&resp);
print_headers(&resp);
let mime = get_content_type(&resp);
let body = resp.text().await?;
print_body(mime, &body);
Ok(())
}
/// 将服务器返回的 content-type 解析成 Mime 类型
fn get_content_type(resp: &Response) -> Option<Mime> {
resp.headers()
.get(header::CONTENT_TYPE)
.map(|v| v.to_str().unwrap().parse().unwrap())
}
/// 程序的入口函数，因为在 HTTP 请求时我们使用了异步处理，所以这里引入 tokio
#[tokio::main]
async fn main() -> Result<()> {
let opts: Opts = Opts::parse();
let mut headers = header::HeaderMap::new();
// 为我们的 http 客户端添加一些缺省的 HTTP 头
headers.insert("X-POWERED-BY", "Rust".parse()?);
headers.insert(header::USER_AGENT, "Rust Httpie".parse()?);
let client = reqwest::Client::builder()
.default_headers(headers)
.build()?;
let result = match opts.subcmd {
SubCommand::Get(ref args) => get(client, args).await?,
SubCommand::Post(ref args) => post(client, args).await?,
};
Ok(result)
}
fn print_syntect(s: &str, ext: &str) {
// 将字符串按照指定语法进行高亮并打印的功能。
// Load these once at the start of your program
let ps = SyntaxSet::load_defaults_newlines();
let ts = ThemeSet::load_defaults();
let syntax = ps.find_syntax_by_extension(ext).unwrap();
let mut h = HighlightLines::new(syntax, &ts.themes["base16-ocean.dark"]);
for line in LinesWithEndings::from(s) {
let ranges_result: Result<Vec<(Style, &str)>, _> = h.highlight_line(line, &ps);
let ranges = ranges_result.unwrap(); // 或者使用 expect() 方法处理错误
let escaped = as_24_bit_terminal_escaped(&ranges[..], true);
print!("{}", escaped);
}
}
// 仅在 cargo test 时才编译
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn parse_url_works() {
assert!(parse_url("abc").is_err());
assert!(parse_url("http://abc.xyz").is_ok());
assert!(parse_url("https://httpbin.org/post").is_ok());
}
#[test]
fn parse_kv_pair_works() {
assert!(parse_kv_pair("a").is_err());
assert_eq!(
parse_kv_pair("a=1").unwrap(),
KvPair {
k: "a".into(),
v: "1".into()
}
);
assert_eq!(
parse_kv_pair("b=").unwrap(),
KvPair {
k: "b".into(),
v: "".into()
}
);
}
}Cargo.toml
rust
[package]
name = "httpie"
version = "0.1.0"
edition = "2024"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
anyhow = "1.0.71" # 错误处理
clap = { version = "4.3.9", features = ["derive"] } # 命令行解析
colored = "2.0.0" # 命令终端多彩显示
jsonxf = "1.1.1" # JSON pretty print 格式化
mime = "0.3.17" # 处理 mime 类型
reqwest = { version = "0.11.18", features = ["json"] } # HTTP 客户端
tokio = { version = "1.29.0", features = ["full"] } # 异步处理库
syntect = "5.0.0"使用代码行数统计工具 tokei 可以看到
bash
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 24.7s
➜ tokei src/main.rs
===============================================================================
Language Files Lines Code Comments Blanks
===============================================================================
Rust 1 204 155 20 29
|- Markdown 1 16 0 16 0
(Total) 220 155 36 29
===============================================================================
Total 1 204 155 20 29
===============================================================================
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ 运行
bash
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ cargo build --quiet
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 3.5s
➜ target/debug/httpie post https://httpbin.org/post a=1 b
error: invalid value 'b' for '[BODY]...': Failed to parse b
For more information, try '--help'.
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ target/debug/httpie post abc a=1
error: invalid value 'abc' for '<URL>': relative URL without a base
For more information, try '--help'.
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ target/debug/httpie post https://httpbin.org/post a=1 b=2
HTTP/1.1 200 OK
date: "Fri, 30 Jun 2025 02:56:38 GMT"
content-type: "application/json"
content-length: "472"
connection: "keep-alive"
server: "gunicorn/19.9.0"
access-control-allow-origin: "*"
access-control-allow-credentials: "true"
{
"args": {},
"data": "{\"a\":\"1\",\"b\":\"2\"}",
"files": {},
"form": {},
"headers": {
"Accept": "*/*",
"Content-Length": "17",
"Content-Type": "application/json",
"Host": "httpbin.org",
"User-Agent": "Rust Httpie",
"X-Amzn-Trace-Id": "Root=1-649e4444-7a2f12631acc444061bfc41c",
"X-Powered-By": "Rust"
},
"json": {
"a": "1",
"b": "2"
},
"origin": "222.128.44.77",
"url": "https://httpbin.org/post"
}
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 38.3s
➜ 测试
bash
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 38.3s
➜ cargo test
Compiling httpie v0.1.0 (/Users/qiaopengjun/Code/rust/httpie)
Finished test [unoptimized + debuginfo] target(s) in 1.23s
Running unittests src/main.rs (target/debug/deps/httpie-0758ccd2852d828e)
running 2 tests
test tests::parse_kv_pair_works ... ok
test tests::parse_url_works ... ok
test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ 使用 cargo build --release，编译出 release 版本
bash
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ cargo build --release
Compiling libc v0.2.147
Compiling autocfg v1.1.0
Compiling proc-macro2 v1.0.63
Compiling unicode-ident v1.0.9
Compiling quote v1.0.29
Compiling cfg-if v1.0.0
Compiling bitflags v1.3.2
Compiling io-lifetimes v1.0.11
Compiling itoa v1.0.6
Compiling rustix v0.37.20
Compiling once_cell v1.18.0
Compiling parking_lot_core v0.9.8
Compiling pin-project-lite v0.2.9
Compiling smallvec v1.10.0
Compiling scopeguard v1.1.0
Compiling futures-core v0.3.28
Compiling bytes v1.4.0
Compiling serde v1.0.164
Compiling core-foundation-sys v0.8.4
Compiling hashbrown v0.12.3
Compiling lock_api v0.4.10
Compiling indexmap v1.9.3
Compiling tokio v1.29.0
Compiling futures-task v0.3.28
Compiling fnv v1.0.7
Compiling tempfile v3.6.0
Compiling slab v0.4.8
Compiling tracing-core v0.1.31
Compiling futures-util v0.3.28
Compiling memchr v2.5.0
Compiling lazy_static v1.4.0
Compiling syn v2.0.22
Compiling tracing v0.1.37
Compiling errno v0.3.1
Compiling signal-hook-registry v1.4.1
Compiling socket2 v0.4.9
Compiling mio v0.8.8
Compiling num_cpus v1.16.0
Compiling core-foundation v0.9.3
Compiling security-framework-sys v2.9.0
Compiling tokio-macros v2.1.0
Compiling parking_lot v0.12.1
Compiling http v0.2.9
Compiling futures-channel v0.3.28
Compiling httparse v1.8.0
Compiling futures-sink v0.3.28
Compiling pkg-config v0.3.27
Compiling fastrand v1.9.0
Compiling pin-utils v0.1.0
Compiling tinyvec_macros v0.1.1
Compiling cc v1.0.79
Compiling native-tls v0.2.11
Compiling tinyvec v1.6.0
Compiling onig_sys v69.8.1
Compiling security-framework v2.9.1
Compiling try-lock v0.2.4
Compiling crc32fast v1.3.2
Compiling percent-encoding v2.3.0
Compiling utf8parse v0.2.1
Compiling serde_json v1.0.99
Compiling ryu v1.0.13
Compiling anstyle-parse v0.2.1
Compiling form_urlencoded v1.2.0
Compiling want v0.3.1
Compiling unicode-normalization v0.1.22
Compiling http-body v0.4.5
Compiling is-terminal v0.4.7
Compiling httpdate v1.0.2
Compiling anstyle-query v1.0.0
Compiling unicode-bidi v0.3.13
Compiling thiserror v1.0.40
Compiling colorchoice v1.0.0
Compiling safemem v0.3.3
Compiling base64 v0.21.2
Compiling anstyle v1.0.1
Compiling tower-service v0.3.2
Compiling adler v1.0.2
Compiling time-core v0.1.1
Compiling anstream v0.3.2
Compiling time v0.3.22
Compiling miniz_oxide v0.7.1
Compiling line-wrap v0.1.1
Compiling idna v0.4.0
Compiling quick-xml v0.28.2
Compiling thiserror-impl v1.0.40
Compiling strsim v0.10.0
Compiling anyhow v1.0.71
Compiling same-file v1.0.6
Compiling heck v0.4.1
Compiling clap_lex v0.5.0
Compiling linked-hash-map v0.5.6
Compiling unicode-width v0.1.10
Compiling yaml-rust v0.4.5
Compiling clap_builder v4.3.9
Compiling clap_derive v4.3.2
Compiling getopts v0.2.21
Compiling walkdir v2.3.3
Compiling tokio-util v0.7.8
Compiling h2 v0.3.20
Compiling tokio-native-tls v0.3.1
Compiling flate2 v1.0.26
Compiling plist v1.4.3
Compiling url v2.4.0
Compiling bincode v1.3.3
Compiling serde_urlencoded v0.7.1
Compiling serde_derive v1.0.164
Compiling atty v0.2.14
Compiling encoding_rs v0.8.32
Compiling log v0.4.19
Compiling mime v0.3.17
Compiling ipnet v2.8.0
Compiling regex-syntax v0.6.29
Compiling hyper v0.14.27
Compiling colored v2.0.0
Compiling clap v4.3.9
Compiling jsonxf v1.1.1
Compiling hyper-tls v0.5.0
Compiling reqwest v0.11.18
Compiling onig v6.4.0
Compiling syntect v5.0.0
Compiling httpie v0.1.0 (/Users/qiaopengjun/Code/rust/httpie)
Finished release [optimized] target(s) in 20.65s
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 20.7s
➜ 将其拷贝到某个在 $PATH下的目录，然后体验一下：
bash
httpie on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 20.7s
➜ mcd pub
httpie/pub on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ ls
httpie/pub on main [!] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ cp ../target/release/httpie ./
httpie/pub on main [!?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ ls
httpie
httpie/pub on main [!?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ ./httpie
A naive httpie implementation with Rust, can you imagine how easy it is?
Usage: httpie <COMMAND>
Commands:
get feed get with an url and we will retrieve the response for you
post feed post with an url and optional key=value pairs. We will post the data as JSON, and retrieve the response for you
help Print this message or the help of the given subcommand(s)
Options:
-h, --help Print help
-V, --version Print version
httpie/pub on main [!?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ 测试一下效果：
bash
httpie/pub on main [!?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base
➜ ./httpie post https://httpbin.org/post greeting=hola name=Tyr
HTTP/1.1 200 OK
date: "Fri, 30 Jun 2025 03:15:49 GMT"
content-type: "application/json"
content-length: "502"
connection: "keep-alive"
server: "gunicorn/19.9.0"
access-control-allow-origin: "*"
access-control-allow-credentials: "true"
{
"args": {},
"data": "{\"greeting\":\"hola\",\"name\":\"Tyr\"}",
"files": {},
"form": {},
"headers": {
"Accept": "*/*",
"Content-Length": "32",
"Content-Type": "application/json",
"Host": "httpbin.org",
"User-Agent": "Rust Httpie",
"X-Amzn-Trace-Id": "Root=1-649e48e3-5fb585884394bb66433bf8a5",
"X-Powered-By": "Rust"
},
"json": {
"greeting": "hola",
"name": "Tyr"
},
"origin": "222.128.44.77",
"url": "https://httpbin.org/post"
}
httpie/pub on main [!?] is 📦 0.1.0 via 🦀 1.88.0 via 🅒 base took 6.6s
➜ 总结
通过对这个类 HTTPie 工具的完整构建，我们成功地展现了如何运用 Rust 及其生态系统，高效地完成一个功能强大且用户友好的 CLI 应用。
回顾整个构建过程，可以清晰地看到 Rust 在该领域的几大核心优势：
- 现代化的包管理：Cargo 工具链让项目创建、依赖管理和编译发布流程化且高效。
- 强大的生态系统：我们轻松集成了 clap、reqwest、tokio、syntect 等高质量的库，极大地加速了开发进程。
- 安全与性能：Rust 的语言特性在编译期规避了大量潜在错误，同时保证了工具的运行时性能。
- 出色的表达力：无论是 trait 的实现还是 async/await 异步语法，都让代码逻辑清晰，易于维护。
这个项目虽小，却完整覆盖了 CLI 应用的关键环节。它作为一个具体的实践案例，有力地证明了 Rust 是构建高性能、高可靠性系统工具的绝佳选择。