What are the alternatives to Reqwest for web scraping in Rust?

In Rust, web scraping can be achieved using several libraries, and while reqwest is a popular choice for making HTTP requests, you might be looking for alternatives that offer different features or are more suited to your specific needs. Here are some alternatives to reqwest for web scraping in Rust:

1. surf

surf is an asynchronous HTTP client built on top of std::future. It's framework-agnostic and can be used with any async runtime.

// Add the following to your Cargo.toml
// surf = "2.3.2"

use surf;

#[async_std::main] // or #[tokio::main]
async fn main() -> surf::Result<()> {
    let mut response = surf::get("https://example.com").await?;
    let body = response.body_string().await?;
    println!("Body:\n{}", body);
    Ok(())
}

2. ureq

ureq is a simple, safe HTTP client without async runtime dependencies, which means it's synchronous and blocks the current thread until the request completes.

// Add the following to your Cargo.toml
// ureq = "2.2.0"

use ureq;

fn main() -> Result<(), ureq::Error> {
    let response = ureq::get("https://example.com").call()?;
    let body = response.into_string()?;
    println!("Body:\n{}", body);
    Ok(())
}

3. isahc

isahc is an HTTP client that uses the curl library under the hood. It supports both synchronous and asynchronous requests.

// Add the following to your Cargo.toml
// isahc = "1.5.1"

use isahc::prelude::*;

fn main() -> Result<(), isahc::Error> {
    let mut response = isahc::get("https://example.com")?;
    let body = response.text()?;
    println!("Body:\n{}", body);
    Ok(())
}

4. hyper

hyper is a fast HTTP implementation written in and for Rust. It's a lower-level library compared to reqwest and is often used as a building block for other HTTP clients.

// Add the following to your Cargo.toml
// hyper = "0.14.9"
// tokio = { version = "1", features = ["full"] }

use hyper::{Body, Client, Uri};
use hyper::client::HttpConnector;
use tokio;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let client = Client::<HttpConnector, Body>::new();
    let uri = "http://example.com".parse::<Uri>()?;
    let res = client.get(uri).await?;

    let body_bytes = hyper::body::to_bytes(res.into_body()).await?;
    let body = String::from_utf8(body_bytes.to_vec())?;
    println!("Body:\n{}", body);

    Ok(())
}

5. reqwest (blocking)

While reqwest is known for its async capabilities, it also offers a blocking client for those who prefer writing synchronous code.

// Add the following to your Cargo.toml
// reqwest = { version = "0.11.4", features = ["blocking"] }

use reqwest;

fn main() -> Result<(), reqwest::Error> {
    let body = reqwest::blocking::get("https://example.com")?.text()?;
    println!("Body:\n{}", body);
    Ok(())
}

Each of these libraries has its own strengths and trade-offs. For instance, surf and isahc provide async support and are suitable for applications that require non-blocking IO. ureq, on the other hand, is ideal for simpler scripts or applications where asynchronous execution is not necessary. hyper gives you fine-grained control over the HTTP stack but requires more setup and can be more complex to use.

When choosing an alternative, consider your project's requirements, such as the need for asynchronous support, simplicity, or low-level control.