use std::env; use std::fs::File; use std::io::{BufRead, BufReader}; use std::process; fn main() { let path = env::args().last().unwrap(); let mut file = BufReader::new(File::open(path).unwrap()); let mut line = String::new(); file.read_line(&mut line).unwrap(); process::exit(line.trim().parse().unwrap()); }