use clap::clap_app; fn main() { // This example shows how to create an application with several arguments using macro builder. // It combines the simplicity of the from_usage methods and the performance of the Builder Pattern. // // The example below is functionally identical to the one in 01a_quick_example.rs and 01b_quick_example.rs // // 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 = clap_app!(myapp => (version: "1.0") (author: "Kevin K. ") (about: "Does awesome things") (@arg CONFIG: -c --config +takes_value "Sets a custom config file") (@arg INPUT: +required "Sets the input file to use") (@arg debug: -d ... "Sets the level of debugging information") (@subcommand test => (about: "controls testing features") (version: "1.3") (author: "Someone E. ") (@arg verbose: -v --verbose "Print test information verbosely") ) ) .get_matches(); // Calling .unwrap() is safe here because "INPUT" is required (if "INPUT" wasn't // required we could have used an 'if let' to conditionally get the value) println!("Using input file: {}", matches.value_of("INPUT").unwrap()); // Gets a value for config if supplied by user, or defaults to "default.conf" let config = matches.value_of("CONFIG").unwrap_or("default.conf"); println!("Value for config: {}", config); // Vary the output based on how many times the user used the "debug" flag // (i.e. 'myapp -d -d -d' or 'myapp -ddd' vs 'myapp -d' 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"), _ => println!("Don't be crazy"), } // You can information about subcommands by requesting their matches by name // (as below), requesting just the name used, or both at the same time if let Some(matches) = matches.subcommand_matches("test") { if matches.is_present("verbose") { println!("Printing verbosely..."); } else { println!("Printing normally..."); } } // more program logic goes here... }