Question

For a little fun我想在Rust中创建一个简单的HTTP请求。我把它扔在一起，效果很好：

use std::io::TcpStream;

fn main() {
    // This just does a "GET /" to www.stroustrup.com
    println!("Establishing connection...");
    let mut stream = TcpStream::connect("www.stroustrup.com:80").unwrap();

    println!("Writing HTTP request...");
    // unwrap() the result to make sure it succeeded, at least
    let _ = stream.write(b"GET / HTTP/1.1\r\n\
                           Host: www.stroustrup.com\r\n\
                           Accept: */*\r\n\
                           Connection: close\r\n\r\n").unwrap();

    println!("Reading response...");
    let response = stream.read_to_string().unwrap();

    println!("Printing response:");
    println!("{}", response);
}

回应是：

Establishing connection...
Writing HTTP request...
Reading response...
Printing response:
HTTP/1.1 200 OK
...and the rest of the long HTTP response with all the HTML as I'd expect...

但是，如果我将请求更改为/C++.html而不是/：

use std::io::TcpStream;

fn main() {
    // The only change is to "GET /C++.html" instead of "GET /"
    println!("Establishing connection...");
    let mut stream = TcpStream::connect("www.stroustrup.com:80").unwrap();

    println!("Writing HTTP request...");
    // unwrap() the result to make sure it succeeded, at least
    let _ = stream.write(b"GET /C++.html HTTP/1.1\r\n\
                           Host: www.stroustrup.com\r\n\
                           Accept: */*\r\n\
                           Connection: close\r\n\r\n").unwrap();

    println!("Reading response...");
    let response = stream.read_to_string().unwrap();

    println!("Printing response:");
    println!("{}", response);
}

套接字返回"invalid input"：

Establishing connection...
Writing HTTP request...
Reading response...
thread '<main>' panicked at 'called `Result::unwrap()` on an `Err` value: invalid input', /Users/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-mac/build/src/libcore/result.rs:746

为什么套接字返回"invalid input"？ TCP套接字不知道HTTP协议（我用telnet和netcat测试了我的请求：它是正确的），所以它不能抱怨HTTP请求/响应。

"invalid input"在这里意味着什么？为什么这不起作用？

我的锈版（我在OS X 10.10.1上）：

$ rustc --version
rustc 1.0.0-nightly (ea6f65c5f 2015-01-06 19:47:08 +0000)

Answer 1

"invalid input"错误不是来自套接字。它来自String。如果read_to_string()调用更改为read_to_end()，则响应成功。显然，响应不是有效的UTF-8。

更明确地说，代码：

println!("Reading response...");
let response = stream.read_to_end().unwrap();

println!("Printing response:");
println!("{}", String::from_utf8(response));

返回：

Err(invalid utf-8: invalid byte at index 14787)

所以HTTP响应很糟糕。查看网页，错误就在这里（�字符是问题）：

Lang.Next'14 Keynote: What � if anything � have we learned from C++?

Answer 2

违规字符为0x96，确实无效utf-8。它应该是U + 2013 - 该文档是iso-8859-1或Windows 1252.该HTML存在许多其他问题，例如未转义的＆＃; p。

。

是什么导致Rust的TcpSocket :: write（）返回＆＃34;无效输入＆＃34;？

2 个答案: