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rustclap

How to use unspecified arguments with clap


I want to create a CLI application using the clap library. The problem I have is that I want to use my application like this :

./my_app file.txt read2.txt -d

The objective is that I can recover in my program in the form of Vec with file.txt read2.txt values.

my code :

use clap::{App, load_yaml};

#[derive(Debug)]
enum EFlag {
    Debug,
    None,
}

#[derive(Debug)]
pub struct Flag {
    debug: EFlag,
}

impl Flag {
    pub fn new() -> Flag {
        Flag {
            debug: EFlag::None,
        }
    }

    pub fn fill_flag(&mut self) {
        let yaml = load_yaml!("cli.yaml");
        let matches = App::from(yaml).get_matches();

        match matches.is_present("debug") {
            true => self.debug = EFlag::Debug,
            _ => self.debug = EFlag::None,
        }
        // HERE I WANT TO RECEIVE file.txt file2.txt
    }
}
fn main() {
    let mut flag = Flag::new();
    flag.fill_flag();
}

I use the beta version of clap to create a yaml file to manage the flags.

the yaml file :

name: bs-script
version: "1.0.0"
author: Clement B. <[email protected]>
about: Write perform, secure and easy script with an Rust script interpretor
args:
  - debug:
      short: d
      long: debug
      about: display debug information

Solution

  • To have an argument accept zero-to-many values, you just need to specify multiple: true.

    - files:
        multiple: true
    

    Then to obtain the files you'd use values_of() along with a collect::<Vec<&str>>():

    if let Some(files) = matches.values_of("files") {
        let files = files.collect::<Vec<_>>();
    
        println!("{:?}", files);
    }
    
    // Prints nothing                     for `cargo run -- -d`
    // Prints `["file.txt"]`              for `cargo run -- file.txt -d`
    // Prints `["file.txt", "read2.txt"]` for `cargo run -- file.txt read2.txt -d`
    

    Here's the complete cli.yaml:

    name: bs-script
    version: "1.0.0"
    author: Clement B. <[email protected]>
    about: Write perform, secure and easy script with an Rust script interpretor
    args:
      - files:
          multiple: true
          about: Files
      - debug:
          short: d
          long: debug
          about: display debug information