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Diffstat (limited to 'clap/examples/01c_quick_example.rs')
| -rw-r--r-- | clap/examples/01c_quick_example.rs | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/clap/examples/01c_quick_example.rs b/clap/examples/01c_quick_example.rs new file mode 100644 index 0000000..071bdc0 --- /dev/null +++ b/clap/examples/01c_quick_example.rs @@ -0,0 +1,75 @@ +#[macro_use] +extern crate clap; + +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. <kbknapp@gmail.com>") + (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. <someone_else@other.com>") + (@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"), + 3 | _ => 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... +} |