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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...
}