mirror of
https://github.com/clap-rs/clap
synced 2024-12-15 15:22:30 +00:00
127 lines
4.4 KiB
Markdown
127 lines
4.4 KiB
Markdown
# StructOpt [](https://travis-ci.org/TeXitoi/structopt) [](https://crates.io/crates/structopt) [](https://docs.rs/structopt)
|
|
|
|
Parse command line argument by defining a struct. It combines [clap](https://crates.io/crates/clap) with custom derive.
|
|
|
|
## Documentation
|
|
|
|
Find it on [Docs.rs](https://docs.rs/structopt). You can also check the [examples](https://github.com/TeXitoi/structopt/tree/master/examples) and the [changelog](https://github.com/TeXitoi/structopt/blob/master/CHANGELOG.md).
|
|
|
|
## Example
|
|
|
|
Add `structopt` to your dependencies of your `Cargo.toml`:
|
|
```toml
|
|
[dependencies]
|
|
structopt = "0.2"
|
|
```
|
|
|
|
And then, in your rust file:
|
|
```rust
|
|
#[macro_use]
|
|
extern crate structopt;
|
|
|
|
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.
|
|
/// Activate debug mode
|
|
#[structopt(short = "d", long = "debug")]
|
|
debug: bool,
|
|
|
|
// The number of occurences of the `v/verbose` flag
|
|
/// Verbose mode (-v, -vv, -vvv, etc.)
|
|
#[structopt(short = "v", long = "verbose", parse(from_occurrences))]
|
|
verbose: u8,
|
|
|
|
/// Set speed
|
|
#[structopt(short = "s", long = "speed", default_value = "42")]
|
|
speed: f64,
|
|
|
|
/// Output file
|
|
#[structopt(short = "o", long = "output", parse(from_os_str))]
|
|
output: PathBuf,
|
|
|
|
/// Number of cars
|
|
#[structopt(short = "c", long = "nb-cars")]
|
|
nb_cars: Option<i32>,
|
|
|
|
/// admin_level to consider
|
|
#[structopt(short = "l", long = "level")]
|
|
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 0.2.0
|
|
Guillaume Pinot <texitoi@texitoi.eu>
|
|
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
|
|
|
|
OPTIONS:
|
|
-c, --car <car> Number of car
|
|
-l, --level <level>... admin_level to consider
|
|
-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, output: "foo.txt", car: None, level: [], files: [] }
|
|
$ ./basic -o foo.txt -dvvvs 1337 -l alice -l bob --car 4 bar.txt baz.txt
|
|
Opt { debug: true, verbose: 3, speed: 1337, output: "foo.txt", car: Some(4), level: ["alice", "bob"], files: ["bar.txt", "baz.txt"] }
|
|
```
|
|
|
|
## Why
|
|
|
|
I use [docopt](https://crates.io/crates/docopt) since a long time (pre rust 1.0). I really like the fact that you have a structure with the parsed argument: no need to convert `String` to `f64`, no useless `unwrap`. But on the other hand, I don't like to write by hand the usage string. That's like going back to the golden age of WYSIWYG editors. Field naming is also a bit artificial.
|
|
|
|
Today, the new standard to read command line arguments in Rust is [clap](https://crates.io/crates/clap). This library is so feature full! But I think there is one downside: even if you can validate argument and expressing that an argument is required, you still need to transform something looking like a hashmap of string vectors to something useful for your application.
|
|
|
|
Now, there is stable custom derive. Thus I can add to clap the automatic conversion that I miss. Here is the result.
|
|
|
|
## License
|
|
|
|
Licensed under either of
|
|
|
|
- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or <https://www.apache.org/licenses/LICENSE-2.0>)
|
|
- MIT license ([LICENSE-MIT](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.
|
|
|