Table of content

Why Rust?

Like many before me, I have gained interest in the rust programming language. My main interest comes from the fact that it can be used for embedded programming. There is a lot of activity on the topic, see Embedded Rust for more information. Before I feel comfortable diving into this world, I want to learn the basics.

100 day Challenge

That is why I’m starting a 100 day 100 snippet challenge in rust, to motivate myself. Rules of this are:

  • 1 unique code snippet per day for 100 days
  • Come up with a challenge
  • Solve the challenge
  • Upload and present
  • ???
  • Profit

First challenge

Challenge

Screen scrape a random recipe name from chefkoch.de and display its name on the terminal

From the site random recipes are displayed, so what I must do is

Lets test with bash, what needs to be done to screen scrape the right stuff

	#!/bin/bash
	curl -s https://www.chefkoch.de/rezepte/was-koche-ich-heute/|grep -Eo "(http|https)://www.chefkoch.de/rezepte/[a-zA-Z0-9./?=_%:-]*" | sort -u|cut -d/ -f6|cut -d. -f1|tr - " "|tail -1

Will give us a menu suggestion

Gefuellte Muschelnudeln

Do this in rust.

Solution

First we need to download the web page reqwest crate seems suitable for this job. Next the document is parsed with select and filtered.

	use select::document::Document;
	use select::predicate::Name;

	fn main() -> Result<(), Box<dyn std::error::Error>> {
	    /* Fetch the website with GET Request */
	    let body =
	        reqwest::blocking::get("https://www.chefkoch.de/rezepte/was-koche-ich-heute/")?.text()?;
	    /* Parse the HTML txt, extract the urls and filter the relevant ones */
	    let yum = Document::from(body.as_str())
	        .select(Name("a"))
	        .filter_map(|n| n.attr("href"))
	        .filter(|x| x.contains("www.chefkoch.de/rezepte/"))
	        .next()
	        .unwrap()
	        .split("/")
	        .last()
	        .unwrap()
	        .replace(".html", "")
	        .replace("-", " ");
	    println!("{}", yum);
	    Ok(())
	}

Next question, where can I have live demos of my code? For now I’ll upload it to my github page, see