gistfile1.rs

use std::env::args;
use std::io::{Error, Read};
use std::fs::File;

fn run(filename : &str) -> Result<(), Error> {
    let mut f = try!(File::open(filename));
    let mut s = String::new();
    try!(f.read_to_string(&mut s));
    println!("{}", s);
    return Ok(());
}

fn usage() {
    println!("To use:\nprog <filename>");
}

fn main() {
    let mut arglist = args().skip(1);
    match arglist.next() {
        Some(ref filename) if arglist.count() == 0 => {
            println!("Loading configuration from {}.", filename);
            match run(filename) {
                Ok(_) => return (),
                Err(e) => println!("Error: {}", e)
            }
        }
        _ => usage()
    }
}