clap/examples/myapp.rs

extern crate clap;

use clap::{App, Arg, SubCommand};

fn main() {

	// Create an application with 5 possible arguments (2 auto generated) and 2 subcommands (1 auto generated)
	//	- A config file
	//		+ Uses "-c filename" or "--config filename"
	//	- An output file
	//		+ A positional argument (i.e. "$ myapp output_filename")
	//	- A debug flag
	//		+ Uses "-d" or "--debug"
	//		+ Allows multiple occurrences of such as "-dd" (for vary levels of debugging, as an example)
	//	- A help flag (automatically generated by clap)
	//		+ Uses "-h" or "--help" (Only autogenerated if you do NOT specify your own "-h" or "--help")
	//	- A version flag (automatically generated by clap)
	//		+ Uses "-v" or "--version" (Only autogenerated if you do NOT specify your own "-v" or "--version")
	//	- A subcommand "test" (subcommands behave like their own apps, with their own arguments
	//		+ Used by "$ myapp test" with the following arguments
	//			> A list flag
	//				= Uses "-l" (usage is "$ myapp test -l"
	//			> A help flag (automatically generated by clap
	//				= Uses "-h" or "--help" (full usage "$ myapp test -h" or "$ myapp test --help")
	//			> A version flag (automatically generated by clap
	//				= Uses "-v" or "--version" (full usage "$ myapp test -v" or "$ myapp test --version")
	//	- A subcommand "help" (automatically generated by clap because we specified a subcommand of our own)
	//		+ Used by "$ myapp help" (same functionality as "-h" or "--help")
	let matches = App::new("MyApp")
						.version("1.0")
						.author("Kevin K. <kbknapp@gmail.com>")
						.about("Does awesome things")
						.arg(Arg::new("config")
									.short("c")
									.long("config")
									.help("Sets a custom config file")
									.takes_value(true))
						.arg(Arg::new("output")
									.help("Sets an optional output file")
									.index(1))
						.arg(Arg::new("debug")
									.short("d")
 									.multiple(true)
									.help("Turn debugging information on"))
						.subcommand(SubCommand::new("test")
												.about("does testing things")
												.arg(Arg::new("list")
															.short("l")
															.help("lists test values")))
						.get_matches();

	// You can check the value provided by positional arguments, or option arguments
	if let Some(o) = matches.value_of("output") {
		println!("Value for output: {}", o);
	}
 
	if let Some(c) = matches.value_of("config") {
		println!("Value for config: {}", c);
	}

	// You can see how many times a particular flag or argument occurred
	// Note, only flags can have multiple occurrences
	match matches.occurrences_of("debug") {
 		0 => println!("Debug mode is off"),
		1 => println!("Debug mode is kind of on"),
		2 => println!("Debug mode is on"),
		3 | _ => println!("Don't be crazy"),
 	}

	// You can check for the existance of subcommands, and if found use their
	// matches just as you would the top level app
 	if let Some(ref matches) = matches.subcommand_matches("test") {
 		// "$ myapp test" was run
 		if matches.is_present("list") {
 			// "$ myapp test -l" was run
 			println!("Printing testing lists...");
 		} else {
 			println!("Not printing testing lists...");
 		}
 	}
 	
 	
	// Continued program logic goes here...
}