vendor/clap-3.2.20/examples/tutorial_builder/01_quick.rs

   1 use std::path::PathBuf;
   2
   3 use clap::{arg, command, value_parser, ArgAction, Command};
   4
   5 fn main() {
   6     let matches = command!() // requires `cargo` feature
   7         .arg(arg!([name] "Optional name to operate on"))
   8         .arg(
   9             arg!(
  10                 -c --config <FILE> "Sets a custom config file"
  11             )
  12             // We don't have syntax yet for optional options, so manually calling `required`
  13             .required(false)
  14             .value_parser(value_parser!(PathBuf)),
  15         )
  16         .arg(
  17             arg!(
  18                 -d --debug "Turn debugging information on"
  19             )
  20             .action(ArgAction::Count),
  21         )
  22         .subcommand(
  23             Command::new("test")
  24                 .about("does testing things")
  25                 .arg(arg!(-l --list "lists test values").action(ArgAction::SetTrue)),
  26         )
  27         .get_matches();
  28
  29     // You can check the value provided by positional arguments, or option arguments
  30     if let Some(name) = matches.get_one::<String>("name") {
  31         println!("Value for name: {}", name);
  32     }
  33
  34     if let Some(config_path) = matches.get_one::<PathBuf>("config") {
  35         println!("Value for config: {}", config_path.display());
  36     }
  37
  38     // You can see how many times a particular flag or argument occurred
  39     // Note, only flags can have multiple occurrences
  40     match matches
  41         .get_one::<u8>("debug")
  42         .expect("Count's are defaulted")
  43     {
  44         0 => println!("Debug mode is off"),
  45         1 => println!("Debug mode is kind of on"),
  46         2 => println!("Debug mode is on"),
  47         _ => println!("Don't be crazy"),
  48     }
  49
  50     // You can check for the existence of subcommands, and if found use their
  51     // matches just as you would the top level cmd
  52     if let Some(matches) = matches.subcommand_matches("test") {
  53         // "$ myapp test" was run
  54         if *matches.get_one::<bool>("list").expect("defaulted by clap") {
  55             // "$ myapp test -l" was run
  56             println!("Printing testing lists...");
  57         } else {
  58             println!("Not printing testing lists...");
  59         }
  60     }
  61
  62     // Continued program logic goes here...
  63 }