01_quick_derive/
01_quick.rs

1use std::path::PathBuf;
2
3use clap::{Parser, Subcommand};
4
5#[derive(Parser)]
6#[command(version, about, long_about = None)]
7struct Cli {
8    /// Optional name to operate on
9    name: Option<String>,
10
11    /// Sets a custom config file
12    #[arg(short, long, value_name = "FILE")]
13    config: Option<PathBuf>,
14
15    /// Turn debugging information on
16    #[arg(short, long, action = clap::ArgAction::Count)]
17    debug: u8,
18
19    #[command(subcommand)]
20    command: Option<Commands>,
21}
22
23#[derive(Subcommand)]
24enum Commands {
25    /// does testing things
26    Test {
27        /// lists test values
28        #[arg(short, long)]
29        list: bool,
30    },
31}
32
33fn main() {
34    let cli = Cli::parse();
35
36    // You can check the value provided by positional arguments, or option arguments
37    if let Some(name) = cli.name.as_deref() {
38        println!("Value for name: {name}");
39    }
40
41    if let Some(config_path) = cli.config.as_deref() {
42        println!("Value for config: {}", config_path.display());
43    }
44
45    // You can see how many times a particular flag or argument occurred
46    // Note, only flags can have multiple occurrences
47    match cli.debug {
48        0 => println!("Debug mode is off"),
49        1 => println!("Debug mode is kind of on"),
50        2 => println!("Debug mode is on"),
51        _ => println!("Don't be crazy"),
52    }
53
54    // You can check for the existence of subcommands, and if found use their
55    // matches just as you would the top level cmd
56    match &cli.command {
57        Some(Commands::Test { list }) => {
58            if *list {
59                println!("Printing testing lists...");
60            } else {
61                println!("Not printing testing lists...");
62            }
63        }
64        None => {}
65    }
66
67    // Continued program logic goes here...
68}
01_quick_derive/01_quick.rs

01_quick_derive/
01_quick.rs
