Fourth Checkpoint, Getting Started with Rust by Building a Tiny Markdown Compiler (https://jesselawson.org/tutorials)

main.rs

// Code for the Fourth Checkpoint
// Tutorial: https://jesselawson.org/rust/get-started-with-rust-by-building-a-tiny-markdown-compiler/
// 
// The purpose of this checkpoint is to ensure that you have a complete copy
// of the code in the tutorial up to the checkpoint. I want you to tinker and
// explore, but to keep up with the rest of the tutorial, make sure your
// code matches this checkpoint. 

fn parse_markdown_file(_file: &str) {
  println!("[ INFO ] Trying to parse {}...", _file);
}

fn get_title() -> String {
  let mut the_title = String::from(env!("CARGO_PKG_NAME"));
  the_title.push_str(" (v");
  the_title.push_str(env!("CARGO_PKG_VERSION"));
  the_title.push_str("), ");
  the_title.push_str(env!("CARGO_PKG_DESCRIPTION"));
  return the_title;
}

fn print_short_banner() {
    println!("{}", get_title());
}

fn print_long_banner() {
    print_short_banner();
  println!("Written by: {}\nHomepage: {}\nUsage: tinymd <somefile>.md\n", 
    env!("CARGO_PKG_AUTHORS"), 
    env!("CARGO_PKG_HOMEPAGE")
  );

}

fn usage() {
    print_long_banner();
    
}

fn main() {
    
    // Collect all arguments in a vector
    let args: Vec<String> = std::env::args().collect();

    // Match the number of arguments. We only want ONE, which means we 
    // should have a vector length of 2: one for the name of the program, 
    // and another for the mardown file we want to parse.
    match args.len() {
        1 => {
            println!("[ ERROR ] You forgot to specify the markdown file to parse!");
            usage();
        },

        // The correct number of args
        2 => {
            parse_markdown_file(&args[1]);
        },

        _ => {
            println!("[ ERROR ] Confusing invocation. See usage below.");
            usage();
        }
    }
}