args

A dead simple implementation of command line argument parsing and validation built on top of the getopts crate.

In order to use the args crate simply create an Args object and begin registering possible command line options via the flag(...) and option(...) methods. Once all options have been registered, parse arguments directly from the command line, or provide a vector of your own arguments.

Any errors encountered during parsing will be returned wrapped in an ArgsError. If there are no errors during parsing values may be retrieved from the args object by simply calling value_of(...) and validated_value_of(...).

That's it!

Usage

This crate is on crates.io and can be used by adding args to the dependencies in your project's Cargo.toml.

toml [dependencies] args = "2.0"

and this to your crate root:

rust extern crate args;

Example

The following example shows simple command line parsing for an application that requires a number of iterations between zero (0) and ten (10) to be specified, accepts an optional log file name and responds to the help flag.

```rust extern crate args; extern crate getopts;

use getopts::Occur;

use args::{Args,ArgsError}; use args::validations::{Order,OrderValidation};

const PROGRAMDESC: &'static str = "Run this program"; const PROGRAMNAME: &'static str = "program";

fn main() { parse(&vec!("-i", "5")); }

fn parse(input: &Vec<&str>) -> Result<(), ArgsError> { let mut args = Args::new(PROGRAMNAME, PROGRAMDESC); args.flag("h", "help", "Print the usage menu"); args.option("i", "iter", "The number of times to run this program", "TIMES", Occur::Req, None); args.option("l", "log_file", "The name of the log file", "NAME", Occur::Optional, None);

try!(args.parse(input));

let help = try!(args.value_of("help"));
if help {
    args.full_usage();
    return Ok(());
}

let gt_0 = Box::new(OrderValidation::new(Order::GreaterThan, 0u32));
let lt_10 = Box::new(OrderValidation::new(Order::LessThanOrEqual, 10u32));

let iters = try!(args.validated_value_of("iter", &[gt_0, lt_10]));
for iter in 0..iters {
    println!("Working on iteration {}", iter);
}
println!("All done.");

Ok(())

} ```