Rust in Action TCP

tcp_request.rs

use std::io::prelude::*;
use std::net::TcpStream;

fn main() -> std::io::Result<()> {
    let mut connection = TcpStream::connect("www.rustinaction.com:80")?;   // We need to specify the port (80) explicitly, TcpStream does not know that this will become a HTTP request.

    connection.write_all(b"GET / HTTP/1.0")?;                              // GET is the HTTP method, / is the resource we're attempting to access and HTTP/1.0 is the protocol version we're requesting. Why 1.0? It does not support "keep alive" requests, which will allow our stream to close without difficulty.
    connection.write_all(b"\r\n")?;                                        // In many networking protocols, \r\n is how a new lines
    connection.write_all(b"Host: www.rustinaction.com")?;                  // The hostname provided on line 5 is actually discarded once it is converted to an IP address. The Host HTTP header allows the server to know which host we're connecting to..
    connection.write_all(b"\r\n\r\n")?;                                    // Two blank lines signifies that we've finished the request.

    std::io::copy(&mut connection, &mut std::io::stdout())?;               // std::io::copy() streams bytes from a Reader to a Writer.

    Ok(())
}