clap/examples/17_yaml.rs
2020-07-20 20:58:34 -03:00

50 lines
1.8 KiB
Rust

// In order to use YAML to define your CLI you must compile clap with the "yaml" feature because
// it's **not** included by default.
//
// In order to do this, ensure your Cargo.toml looks like one of the following:
//
// [dependencies.clap]
// features = ["yaml"]
//
// __OR__
//
// [dependencies]
// clap = { features = ["yaml"] }
// Using yaml requires calling a clap macro `load_yaml!()`.
// Note: If you're using clap as a dependency and don't have a feature for your users called
// "yaml", you'll need to remove the #[cfg(feature = "yaml")] conditional compilation attribute
#[cfg(feature = "yaml")]
fn main() {
use clap::{load_yaml, App};
// To load a yaml file containing our CLI definition such as the example '17_yaml.yaml' we can
// use the convenience macro which loads the file at compile relative to the current file
// similar to how modules are found.
//
// Then we pass that yaml object to App to build the CLI.
//
// Finally we call get_matches() to start the parsing process. We use the matches just as we
// normally would
let yaml = load_yaml!("17_yaml.yaml");
let m = App::from(yaml).get_matches();
// Because the example 17_yaml.yaml is rather large we'll just look a single arg so you can
// see that it works...
if let Some(mode) = m.value_of("mode") {
match mode {
"vi" => println!("You are using vi"),
"emacs" => println!("You are using emacs..."),
_ => unreachable!(),
}
} else {
println!("--mode <MODE> wasn't used...");
}
}
#[cfg(not(feature = "yaml"))]
fn main() {
// As stated above, if clap is not compiled with the YAML feature, it is disabled.
println!("YAML feature is disabled.");
println!("Pass --features yaml to cargo when trying this example.");
}