main.rs

#[macro_use]
extern crate error_chain;

extern crate clap;
extern crate reqwest;

use std::fs::File;
use std::io;

use clap::{App, Arg};

error_chain! {
    foreign_links {
        IoErr(std::io::Error);
        ReqErr(reqwest::Error);
    }
}

fn run(args: &clap::ArgMatches) -> Result<u64> {
    let url = args.value_of("URL").unwrap();
    let file_name = args.value_of("output").unwrap_or("output");

    let mut resp = reqwest::get(url)?;
    let mut output = File::create(file_name)?;

    let b = io::copy(&mut resp, &mut output)?;
    Ok(b)
}

fn main() {
    let matches = App::new("wget")
        .version("0.1")
        .author("me")
        .about("wget clone")
        .arg(
            Arg::with_name("URL")
                .help("the url to get")
                .required(true)
                .index(1),
        )
        .arg(
            Arg::with_name("output")
                .help("the file name to output to")
                .short("O")
                .long("out")
                .value_name("FILE")
                .required(false),
        )
        .get_matches();

    let res = run(&matches);
    if res.is_err() {
        println!("error running get: {}", res.unwrap_err().description());
    } else {
        println!("downloaded {} bytes", res.unwrap());
    }
}