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Diffstat (limited to 'clap/examples/01a_quick_example.rs')
| -rw-r--r-- | clap/examples/01a_quick_example.rs | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/clap/examples/01a_quick_example.rs b/clap/examples/01a_quick_example.rs new file mode 100644 index 0000000..c7fa20f --- /dev/null +++ b/clap/examples/01a_quick_example.rs @@ -0,0 +1,79 @@ +extern crate clap; + +use clap::{App, SubCommand}; + +fn main() { + + // This example shows how to create an application with several arguments using usage strings, which can be + // far less verbose that shown in 01b_QuickExample.rs, but is more readable. The downside is you cannot set + // the more advanced configuration options using this method (well...actually you can, you'll see ;) ) + // + // The example below is functionally identical to the 01b_quick_example.rs and 01c_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 = App::new("MyApp") + .version("1.0") + .author("Kevin K. <kbknapp@gmail.com>") + .about("Does awesome things") + .args_from_usage("-c, --config=[FILE] 'Sets a custom config file' + <output> 'Sets an optional output file' + -d... 'Turn debugging information on'") + .subcommand(SubCommand::with_name("test") + .about("does testing things") + .arg_from_usage("-l, --list '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("d") { + 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 existence of subcommands, and if found use their + // matches just as you would the top level app + if let Some(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... +} |