sha1sum.rs

use std::{fs, env};
use std::fs::metadata;
use sha1::Sha1;

fn dir_format(dir: &str) -> String {
    if let Some(s) = dir.strip_prefix("~") {
        format!("{}{}", env::var("HOME").unwrap(), s)
    } else {
        dir.to_string()
    }
}

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() < 2 {
        panic!("Syntax: <dir>");
    }
    let dir = dir_format(&args[1]);
    let bytes = match fs::read(&dir) {
        Ok(str) => str,
        Err(err) => panic!("{}", err)
    };
    let mut hash = Sha1::new();
    hash.update(&bytes);
    println!("{}", hash.digest());
}