commit	4fe7ddaa487d3fc5aa86e90fb7d2bfd71fce6a25	[log] [tgz]
author	android-build-team Robot <android-build-team-robot@google.com>	Fri Apr 30 01:06:27 2021 +0000
committer	android-build-team Robot <android-build-team-robot@google.com>	Fri Apr 30 01:06:27 2021 +0000
tree	a1f2b136f0951447ee26fd070ec1044f092023a7
parent	c15b161ecaefed71f7464218d0bbe5364bbb7f47 [diff]
parent	892dbbf7fa26c93d4ec6f852f0dd6c8f5026805a [diff]

tree: a1f2b136f0951447ee26fd070ec1044f092023a7

README.md

StructOpt

Parse command line arguments by defining a struct. It combines clap with custom derive.

Documentation

Find it on Docs.rs. You can also check the examples and the changelog.

Example

Add structopt to your dependencies of your Cargo.toml:

[dependencies]
structopt = "0.3"

And then, in your rust file:

use std::path::PathBuf;
use structopt::StructOpt;

/// A basic example
#[derive(StructOpt, Debug)]
#[structopt(name = "basic")]
struct Opt {
    // A flag, true if used in the command line. Note doc comment will
    // be used for the help message of the flag. The name of the
    // argument will be, by default, based on the name of the field.
    /// Activate debug mode
    #[structopt(short, long)]
    debug: bool,

    // The number of occurrences of the `v/verbose` flag
    /// Verbose mode (-v, -vv, -vvv, etc.)
    #[structopt(short, long, parse(from_occurrences))]
    verbose: u8,

    /// Set speed
    #[structopt(short, long, default_value = "42")]
    speed: f64,

    /// Output file
    #[structopt(short, long, parse(from_os_str))]
    output: PathBuf,

    // the long option will be translated by default to kebab case,
    // i.e. `--nb-cars`.
    /// Number of cars
    #[structopt(short = "c", long)]
    nb_cars: Option<i32>,

    /// admin_level to consider
    #[structopt(short, long)]
    level: Vec<String>,

    /// Files to process
    #[structopt(name = "FILE", parse(from_os_str))]
    files: Vec<PathBuf>,
}

fn main() {
    let opt = Opt::from_args();
    println!("{:#?}", opt);
}

Using this example:

$ ./basic
error: The following required arguments were not provided:
    --output <output>

USAGE:
    basic --output <output> --speed <speed>

For more information try --help
$ ./basic --help
basic 0.3.0
Guillaume Pinot <texitoi@texitoi.eu>, others
A basic example

USAGE:
    basic [FLAGS] [OPTIONS] --output <output> [--] [file]...

FLAGS:
    -d, --debug      Activate debug mode
    -h, --help       Prints help information
    -V, --version    Prints version information
    -v, --verbose    Verbose mode (-v, -vv, -vvv, etc.)

OPTIONS:
    -l, --level <level>...     admin_level to consider
    -c, --nb-cars <nb-cars>    Number of cars
    -o, --output <output>      Output file
    -s, --speed <speed>        Set speed [default: 42]

ARGS:
    <file>...    Files to process
$ ./basic -o foo.txt
Opt {
    debug: false,
    verbose: 0,
    speed: 42.0,
    output: "foo.txt",
    nb_cars: None,
    level: [],
    files: [],
}
$ ./basic -o foo.txt -dvvvs 1337 -l alice -l bob --nb-cars 4 bar.txt baz.txt
Opt {
    debug: true,
    verbose: 3,
    speed: 1337.0,
    output: "foo.txt",
    nb_cars: Some(
        4,
    ),
    level: [
        "alice",
        "bob",
    ],
    files: [
        "bar.txt",
        "baz.txt",
    ],
}

StructOpt rustc version policy

Minimum rustc version modification must be specified in the changelog and in the travis configuration.
Contributors can increment minimum rustc version without any justification if the new version is required by the latest version of one of StructOpt's dependencies (cargo update will not fail on StructOpt).
Contributors can increment minimum rustc version if the library user experience is improved.

License

Licensed under either of

Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.