From 5e20a29b4fdc8a2d442d1093681b396dcb4b816b Mon Sep 17 00:00:00 2001 From: Robin Krahl Date: Tue, 7 Jan 2020 11:18:04 +0000 Subject: Add structopt dependency in version 0.3.7 This patch series replaces argparse with structopt in the argument handling code. As a first step, we need structopt as a dependency. Import subrepo structopt/:structopt at efbdda4753592e27bc430fb01f7b9650b2f3174d Import subrepo bitflags/:bitflags at 30668016aca6bd3b02c766e8347e0b4080d4c296 Import subrepo clap/:clap at 784524f7eb193e35f81082cc69454c8c21b948f7 Import subrepo heck/:heck at 093d56fbf001e1506e56dbfa38631d99b1066df1 Import subrepo proc-macro-error/:proc-macro-error at 6c4cfe79a622c5de8ae68557993542be46eacae2 Import subrepo proc-macro2/:proc-macro2 at d5d48eddca4566e5438e8a2cbed4a74e049544de Import subrepo quote/:quote at 727436c6c137b20f0f34dde5d8fda2679b9747ad Import subrepo rustversion/:rustversion at 0c5663313516263059ce9059ef81fc7a1cf655ca Import subrepo syn-mid/:syn-mid at 5d3d85414a9e6674e1857ec22a87b96e04a6851a Import subrepo syn/:syn at e87c27e87f6f4ef8919d0372bdb056d53ef0d8f3 Import subrepo textwrap/:textwrap at abcd618beae3f74841032aa5b53c1086b0a57ca2 Import subrepo unicode-segmentation/:unicode-segmentation at 637c9874c4fe0c205ff27787faf150a40295c6c3 Import subrepo unicode-width/:unicode-width at 3033826f8bf05e82724140a981d5941e48fce393 Import subrepo unicode-xid/:unicode-xid at 4baae9fffb156ba229665b972a9cd5991787ceb7 --- clap/examples/03_args.rs | 84 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 clap/examples/03_args.rs (limited to 'clap/examples/03_args.rs') diff --git a/clap/examples/03_args.rs b/clap/examples/03_args.rs new file mode 100644 index 0000000..c62d576 --- /dev/null +++ b/clap/examples/03_args.rs @@ -0,0 +1,84 @@ +extern crate clap; + +use clap::{App, Arg}; + +fn main() { + // Args describe a possible valid argument which may be supplied by the user at runtime. There + // are three different types of arguments (flags, options, and positional) as well as a fourth + // special type of argument, called SubCommands (which will be discussed separately). + // + // Args are described in the same manner as Apps using the "builder pattern" with multiple + // methods describing various settings for the individual arguments. Or by supplying a "usage" + // string. Both methods have their pros and cons. + // + // Arguments can be added to applications in two manners, one at a time with the arg(), and + // arg_from_usage() method, or multiple arguments at once via a Vec inside the args() method, + // or a single &str describing multiple Args (one per line) supplied to args_from_usage(). + // + // There are various options which can be set for a given argument, some apply to any of the + // three types of arguments, some only apply one or two of the types. *NOTE* if you set + // incompatible options on a single argument, clap will panic! at runtime. This is by design, + // so that you know right away an error was made by the developer, not the end user. + // + // # Help and Version + // clap automatically generates a help and version flag for you, unless you specify your + // own. By default help uses "-h" and "--help", and version uses "-V" and "--version". You can + // safely override "-V" and "-h" to your own arguments, and "--help" and "--version" will still + // be automatically generated for you. + let matches = App::new("MyApp") + // All application settings go here... + + // A simple "Flag" argument example (i.e. "-d") using the builder pattern + .arg(Arg::with_name("debug") + .help("turn on debugging information") + .short("d")) + + // Two arguments, one "Option" argument (i.e. one that takes a value) such + // as "-c some", and one positional argument (i.e. "myapp some_file") + .args(&[ + Arg::with_name("config") + .help("sets the config file to use") + .takes_value(true) + .short("c") + .long("config"), + Arg::with_name("input") + .help("the input file to use") + .index(1) + .required(true) + ]) + + // *Note* the following two examples are convenience methods, if you wish + // to still get the full configurability of Arg::with_name() and the readability + // of arg_from_usage(), you can instantiate a new Arg with Arg::from_usage() and + // still be able to set all the additional properties, just like Arg::with_name() + // + // + // One "Flag" using a usage string + .arg_from_usage("--license 'display the license file'") + + // Two args, one "Positional", and one "Option" using a usage string + .args_from_usage("[output] 'Supply an output file to use' + -i, --int=[IFACE] 'Set an interface to use'") + .get_matches(); + + // Here are some examples of using the arguments defined above. Keep in mind that this is only + // an example, and may be somewhat contrived + // + // First we check if debugging should be on or not + println!("Debugging mode is: {}", if matches.is_present("debug") { "ON" } else { "OFF" }); + + // Next we print the config file we're using, if any was defined with either -c or + // --config + if let Some(config) = matches.value_of("config") { + println!("A config file was passed in: {}", config); + } + + // Let's print the file the user passed in. We can use .unwrap() here becase the arg is + // required, and parsing would have failed if the user forgot it + println!("Using input file: {}", matches.value_of("input").unwrap()); + + // We could continue checking for and using arguments in this manner, such as "license", + // "output", and "interface". Keep in mind that "output" and "interface" are optional, so you + // shouldn't call .unwrap(). Instead, prefer using an 'if let' expression as we did with + // "config" +} -- cgit v1.2.1