>>720
整理するとこれでいいみたい

use std::error::Error;
use std::net::TcpStream;
use std::io::{BufReader, BufRead, Read, Write};
use std::fmt::Write as _;

fn http_get(host_port: &str, path: &str) -> Result<Vec<u8>, Box<dyn Error>> {
　let mut server = TcpStream::connect(host_port)?;
　let mut http = String::new();
　write!(http, "GET {path} HTTP/1.1\r\n")?;
　write!(http, "Host: {host_port}\r\n")?;
　write!(http, "Connection: close\r\n")?;
　write!(http, "\r\n")?;
　server.write_all(http.as_bytes())?;

　let mut server = BufReader::new(server);
　let mut line = String::new();
　server.read_line(&mut line)?;
　if line != "HTTP/1.1 200 OK\r\n" {
　　return Err("HTTP: not 200 OK".into());
　}
　while server.read_line(&mut line)? > 2 {}

　let mut data = Vec::<u8>::new();
　server.read_to_end(&mut data)?;
　Ok(data)
}