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/// Published example from `clap` tutorial (builder)
///
/// E.g. `thag demo/clap_tut_builder_01_quick.rs -- -ddd -c dummy.cfg my_file test -l`
//# Purpose: Demonstrate `clap` CLI using the builder option
//# Categories: CLI, crates, technique
//# Sample arguments: `-- -ddd -c dummy.cfg my_file test -l`
use std::path::PathBuf;
use clap::{arg, command, value_parser, ArgAction, Command};
//# Purpose: Demonstrate `clap` CLI using the builder option
//# Categories: CLI, crates, technique
fn main() {
let matches = command!() // requires `cargo` feature
.arg(arg!([name] "Optional name to operate on"))
.arg(
arg!(
-c --config <FILE> "Sets a custom config file"
)
// We don't have syntax yet for optional options, so manually calling `required`
.required(false)
.value_parser(value_parser!(PathBuf)),
)
.arg(arg!(
-d --debug ... "Turn debugging information on"
))
.subcommand(
Command::new("test")
.about("does testing things")
.arg(arg!(-l --list "lists test values").action(ArgAction::SetTrue)),
)
.get_matches();
// You can check the value provided by positional arguments, or option arguments
if let Some(name) = matches.get_one::<String>("name") {
println!("Value for name: {name}");
}
if let Some(config_path) = matches.get_one::<PathBuf>("config") {
println!("Value for config: {}", config_path.display());
}
// You can see how many times a particular flag or argument occurred
// Note, only flags can have multiple occurrences
match matches
.get_one::<u8>("debug")
.expect("Counts are defaulted")
{
0 => println!("Debug mode is off"),
1 => println!("Debug mode is kind of on"),
2 => println!("Debug mode is on"),
_ => println!("Don't be crazy"),
}
// You can check for the existence of subcommands, and if found use their
// matches just as you would the top level cmd
if let Some(matches) = matches.subcommand_matches("test") {
// "$ myapp test" was run
if matches.get_flag("list") {
// "$ myapp test -l" was run
println!("Printing testing lists...");
} else {
println!("Not printing testing lists...");
}
}
// Continued program logic goes here...
}