mirror of
https://github.com/clap-rs/clap
synced 2024-11-14 08:37:16 +00:00
3be8bcf756
This better models what users should be doing and makes it so all comments are more clear. In a prior commit, when a changed an `exit` to `unwrap`, I disliked the fact that I was mixing an unwrap explanatory comment in with another comment. This makes them stand apart.
50 lines
2.2 KiB
Rust
50 lines
2.2 KiB
Rust
use clap::{App, Arg};
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fn main() {
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// Positional arguments are those values after the program name which are not preceded by any
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// identifier (such as "myapp some_file"). Positionals support many of the same options as
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// flags, as well as a few additional ones.
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let matches = App::new("MyApp")
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// Regular App configuration goes here...
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// We'll add two positional arguments, an input file, and a config file.
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//
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// I'll explain each possible setting that "positionals" accept. Keep in
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// mind that you DO NOT need to set each of these for every flag, only the
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// ones that apply to your individual case.
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.arg(
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Arg::new("input")
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.about("the input file to use") // Displayed when showing help info
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.index(1) // Set the order in which the user must
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// specify this argument (Starts at 1)
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.requires("config") // Says, "If the user uses "input", they MUST
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// also use this other 'config' arg too"
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// Can also specify a list using
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// requires_all(Vec<&str>)
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.required(true), // By default this argument MUST be present
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// NOTE: mutual exclusions take precedence over
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// required arguments
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)
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.arg(Arg::new("config").about("the config file to use").index(2)) // Note, we do not need to specify required(true)
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// if we don't want to, because "input" already
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// requires "config"
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// Note, we also do not need to specify requires("input")
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// because requires lists are automatically two-way
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.get_matches();
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// We can find out whether or not "input" or "config" were used
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if matches.is_present("input") {
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println!("An input file was specified");
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}
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// We can also get the values for those arguments
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if let Some(ref in_file) = matches.value_of("input") {
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println!(
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"Doing work with {} and {}",
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in_file,
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matches
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.value_of("config")
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.expect("'config' is required and parsing will fail if its missing")
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);
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}
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// Continued program logic goes here...
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}
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