rust从0开始写项目-07-如何接受命令行参数clap-02

上篇我们介绍了如何在app内使用clap接受参数，本文介绍下如何使用struct 优雅的接收和校验数据关注 vx golang技术实验室，获取更多golang、rust好文 # 二、derive feature方式个人更喜欢这种方式，代码看起来更简洁 ## 2.1 添加依赖 ``` cargo add clap --features derive ``` 这里是不需要cargo的 ## 2.2 快速开始 ``` #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Clis { /// Optional name to operate on name: Option, /// Sets a custom config file #[arg(short, long, value_name = "FILE")] config: Option, /// Turn debugging information on #[arg(short, long, action = clap::ArgAction::Count)] debug: u8, #[command(subcommand)] command: Option, } #[derive(Subcommand)] enum Commands { /// does testing things Test { /// lists test values #[arg(short, long)] list: bool, }, } fn quick_test(){ let cli = Clis::parse(); if let Some(name) = cli.name.as_ref(){ println!("value for name {name}") } if let Some(config_path) = cli.config.as_deref(){ println!("value for config: {:?}",config_path) } match cli.debug { 0 => println!("debug mode is off"), 1=> println!("debug mode is kind of on"), 2=>println!("debug mode is on"), _=> println!("dont be crazy") } match &cli.command { Some(Commands::Test {list})=>{ if *list{ println!("printing testing lists...") }else{ println!("not printing testing lists...") } } None=>{ } } } ``` 查看help ``` RUST_BACKTRACE=1 cargo run -- --help Compiling my_test v0.1.0 (/Users/zhangqiuli24/Desktop/rust/my_test) Finished dev [unoptimized + debuginfo] target(s) in 5.63s Running `target/debug/my_test --help` Usage: my_test [OPTIONS] [NAME] [COMMAND] Commands: test does testing things help Print this message or the help of the given subcommand(s) Arguments: [NAME] Optional name to operate on Options: -c, --config Sets a custom config file -d, --debug... Turn debugging information on -h, --help Print help -V, --version Print version ``` 调用 ``` RUST_BACKTRACE=1 cargo run -- name -c ./config.toml -d test --list value for name name value for config: "./config.toml" debug mode is kind of on printing testing lists... ``` ## 2.2 配置解析器我们可以是 Parse 属性开启构建解析器 ``` #[derive(Parser)] #[command(name="MyApp")] #[command(author="ZHangQL")] #[command(version="1.0")] #[command(about="这是测试的一些东西",long_about=None)] struct Clic{ #[arg(long)] two:String, #[arg(long)] one:String } fn parse(){ let cli = Clic::parse(); println!("value for two {:?}",cli.two); println!("value for one {:?}",cli.one) } ``` help ``` RUST_BACKTRACE=1 cargo run -- --help Compiling my_test v0.1.0 (/Users/zhangql/Desktop/rust/my_test) Finished dev [unoptimized + debuginfo] target(s) in 6.34s Running `target/debug/my_test --help` 这是测试的一些东西 Usage: my_test --two --one Options: --two --one -h, --help Print help -V, --version Print version cargo run -- -V MyApp 1.0 ``` **我们也可使用使用 #[command(author, version, about)] 形式从 Cargo.toml 读取配置消息** 读取的是cargo.toml的`[package]`信息 ``` #[derive(Parser)] #[command(author, version, about, long_about = None)] // Read from `Cargo.toml` struct Cli { #[arg(long)] two: String, #[arg(long)] one: String, } fn main() { let cli = Cli::parse(); println!("two: {:?}", cli.two); println!("one: {:?}", cli.one); } ``` ## 2.3 Command::next_line_help 换行我们可以使用 #[command(next_line_help = true)] 方法替代 Command::next_line_help ``` RUST_BACKTRACE=1 cargo run -- --help Finished dev [unoptimized + debuginfo] target(s) in 0.98s Running `target/debug/my_test --help` Usage: my_test --two --one Options: --two --one -h, --help Print help -V, --version Print version cargo run -- -V my_test 0.1.0 ``` ## 2.4 添加可选参数 ``` #[derive(Parser)] #[command(author, version, about, long_about = None)] #[command(next_line_help = true)] struct CliW{ name:Option } fn switch(){ let cli = CliW::parse(); println!("value for name {:?}",cli.name); } ``` ``` cargo run -- --help Usage: my_test [NAME] Arguments: [NAME] Options: -h, --help Print help -V, --version Print version RUST_BACKTRACE=1 cargo run -- value for name None RUST_BACKTRACE=1 cargo run -- kkk value for name Some("kkk") ``` ## 2.5 添加多值参数 ``` #[derive(Parser)] #[command(author, version, about, long_about = None)] #[command(next_line_help = true)] struct CliW{ name:Option, more : Vec } fn switch(){ let cli = CliW::parse(); println!("value for name {:?}",cli.name); println!("value for more {:?}",cli.more); } ``` ``` RUST_BACKTRACE=1 cargo run -- --help Usage: my_test [NAME] [MORE]... Arguments: [NAME] [MORE]... Options: -h, --help Print help -V, --version Print version RUST_BACKTRACE=1 cargo run -- kkk more1 more2 m3 value for name Some("kkk") value for more ["more1", "more2", "m3"] ``` ## 2.6 长短名我们可以使用 #[arg(short = ‘n’)] 和 #[arg(long = “name”)] 属性设置参数的短名称和长名称 ``` use clap::Parser; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { #[arg(short, long)] name: Option, } fn main() { let cli = Cli::parse(); println!("name: {:?}", cli.name.as_deref()); } ``` ## 2.7 开启和关闭 ``` use clap::Parser; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { #[arg(short, long)] verbose: bool, } fn main() { let cli = Cli::parse(); println!("verbose: {:?}", cli.verbose); } ``` 需要注意我们默认调用的是clap::ArgAction::SetTrue ## 2.8 参数计数 ``` use clap::Parser; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { #[arg(short, long, action = clap::ArgAction::Count)] verbose: u8, } fn main() { let cli = Cli::parse(); println!("verbose: {:?}", cli.verbose); } ``` ## 2.9 参数默认值 ``` 我们使用 #[arg(default_value_t)] 属性来给参数设置默认值 use clap::Parser; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { #[arg(default_value_t = 2020)] port: u16, } fn main() { let cli = Cli::parse(); println!("port: {:?}", cli.port); } ``` ## 2.10 参数枚举我们使用 #[arg(value_enum)] 设置参数枚举结合枚举类 ``` use clap::{Parser, ValueEnum}; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { /// What mode to run the program in #[arg(value_enum)] mode: Mode, } #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, ValueEnum)] enum Mode { /// Run swiftly Fast, /// Crawl slowly but steadily /// /// This paragraph is ignored because there is no long help text for possible values. Slow, } fn main() { let cli = Cli::parse(); match cli.mode { Mode::Fast => { println!("Hare"); } Mode::Slow => { println!("Tortoise"); } } } ``` ## 2.11 参数校验 ``` use clap::Parser; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { /// Network port to use #[arg(value_parser = clap::value_parser!(u16).range(1..))] port: u16, } fn main() { let cli = Cli::parse(); println!("PORT = {}", cli.port); } ``` ## 2.12 自定义解析 ``` use std::ops::RangeInclusive; use clap::Parser; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { /// Network port to use #[arg(value_parser = port_in_range)] port: u16, } fn main() { let cli = Cli::parse(); println!("PORT = {}", cli.port); } const PORT_RANGE: RangeInclusive = 1..=65535; fn port_in_range(s: &str) -> Result { let port: usize = s .parse() .map_err(|_| format!("`{s}` isn't a port number"))?; if PORT_RANGE.contains(&port) { Ok(port as u16) } else { Err(format!( "port not in range {}-{}", PORT_RANGE.start(), PORT_RANGE.end() )) } } ``` ## 2.13 参数关系 ``` use clap::{Args, Parser}; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { #[command(flatten)] vers: Vers, /// some regular input #[arg(group = "input")] input_file: Option, /// some special input argument #[arg(long, group = "input")] spec_in: Option, #[arg(short, requires = "input")] config: Option, } #[derive(Args)] #[group(required = true, multiple = false)] struct Vers { /// set version manually #[arg(long, value_name = "VER")] set_ver: Option, /// auto inc major #[arg(long)] major: bool, /// auto inc minor #[arg(long)] minor: bool, /// auto inc patch #[arg(long)] patch: bool, } fn main() { let cli = Cli::parse(); // Let's assume the old version 1.2.3 let mut major = 1; let mut minor = 2; let mut patch = 3; // See if --set_ver was used to set the version manually let vers = &cli.vers; let version = if let Some(ver) = vers.set_ver.as_deref() { ver.to_string() } else { // Increment the one requested (in a real program, we'd reset the lower numbers) let (maj, min, pat) = (vers.major, vers.minor, vers.patch); match (maj, min, pat) { (true, _, _) => major += 1, (_, true, _) => minor += 1, (_, _, true) => patch += 1, _ => unreachable!(), }; format!("{major}.{minor}.{patch}") }; println!("Version: {version}"); // Check for usage of -c if let Some(config) = cli.config.as_deref() { let input = cli .input_file .as_deref() .unwrap_or_else(|| cli.spec_in.as_deref().unwrap()); println!("Doing work using input {input} and config {config}"); } } ``` ## 2.14 自定义校验 ``` use clap::error::ErrorKind; use clap::{CommandFactory, Parser}; #[derive(Parser)] #[command(author, version, about, long_about = None)] struct Cli { /// set version manually #[arg(long, value_name = "VER")] set_ver: Option, /// auto inc major #[arg(long)] major: bool, /// auto inc minor #[arg(long)] minor: bool, /// auto inc patch #[arg(long)] patch: bool, /// some regular input input_file: Option, /// some special input argument #[arg(long)] spec_in: Option, #[arg(short)] config: Option, } fn main() { let cli = Cli::parse(); // Let's assume the old version 1.2.3 let mut major = 1; let mut minor = 2; let mut patch = 3; // See if --set-ver was used to set the version manually let version = if let Some(ver) = cli.set_ver.as_deref() { if cli.major || cli.minor || cli.patch { let mut cmd = Cli::command(); cmd.error( ErrorKind::ArgumentConflict, "Can't do relative and absolute version change", ) .exit(); } ver.to_string() } else { // Increment the one requested (in a real program, we'd reset the lower numbers) let (maj, min, pat) = (cli.major, cli.minor, cli.patch); match (maj, min, pat) { (true, false, false) => major += 1, (false, true, false) => minor += 1, (false, false, true) => patch += 1, _ => { let mut cmd = Cli::command(); cmd.error( ErrorKind::ArgumentConflict, "Can only modify one version field", ) .exit(); } }; format!("{major}.{minor}.{patch}") }; println!("Version: {version}"); // Check for usage of -c if let Some(config) = cli.config.as_deref() { let input = cli .input_file .as_deref() // 'or' is preferred to 'or_else' here since `Option::as_deref` is 'const' .or(cli.spec_in.as_deref()) .unwrap_or_else(|| { let mut cmd = Cli::command(); cmd.error( ErrorKind::MissingRequiredArgument, "INPUT_FILE or --spec-in is required when using --config", ) .exit() }); println!("Doing work using input {input} and config {config}"); } } ``` ## 2.15子命令我们使用 #[command(subcommand)] 属性和#[derive(Subcommand)] 联合起来使用声明子命令。 ``` use clap::{Parser, Subcommand}; #[derive(Parser)] #[command(author, version, about, long_about = None)] #[command(propagate_version = true)] struct Cli { #[command(subcommand)] command: Commands, } #[derive(Subcommand)] enum Commands { /// Adds files to myapp Add { name: Option }, } fn main() { let cli = Cli::parse(); // You can check for the existence of subcommands, and if found use their // matches just as you would the top level cmd match &cli.command { Commands::Add { name } => { println!("'myapp add' was used, name is: {name:?}") } } } ``` 本文由[mdnice](https://mdnice.com/?platform=6)多平台发布

rust从0开始写项目-07-如何接受命令行参数clap-02

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