Path to URL: easiest way?

1

Hey folks;

I have a tiny little problem, and I'm not sure of the best way to solve it, so I'd like some advice!

I have a path to a file on disk. Say:

foo/bar.html

But, on Windows, this would be

foo\bar.html

What's the best way to get to the / form, so that the URL would work out?

2

I must be mis-reading the question. Why won't a simple "/" -> "" string replace solve this?

3

I’m trying to be more disciplined about it; that would probably work in the majority of cases, and maybe even all of the ones I care about, but that’s why I’m asking!

4

I think the most disciplined way would be:

  1. parse the path into segments. If this is actually based on an URL, then use an URL-aware parser to get the segments out. If it is an URL, then you can split on /. If the original path is not an URL but some arbitrary platform-specific path format, then this is more complicated.
  2. construct a platform-specific path out of those segments. This is where you would std::path::MAIN_SEPARATOR to join the segments back together.
1 Like
6

As a side-note: Windows API for ages supports / as a valid path separator.

2 Likes
7

You need to be careful about encoding. Each path component has to be urlencoded: "foo bar" -> foo%20bar. Technically, there's no standard encoding for paths in the URLs. On Unix, it usually needs to be whatever the server expects, which tends to be any bytes the filesystem has stored.

path.components().map(|c| urlencode(c.as_bytes())).join("/")
2 Likes
8

That doesn’t help, because that’s about input, not output. When I get a list of files, it will only give me paths with \.

9

Yep! I’ve got that part down. Thanks!

Yeah, so this ends up being easy on Unix, but it gets way worse on Windows, since there's no as_bytes on OsStr.

10

Oh, yeah, and I forgot: OsStr doesn't have a replace, so even this easy method is not as easy as it first looks.

11

This is my current best method, based on some code @alexcrichton wrote:

let mut path_with_forward_slash = OsString::new();

for (i, component) in path.components().enumerate() {
    if i > 0 {
        path_with_forward_slash.push("/");
    }
    path_with_forward_slash.push(component);
}

// if we have a non-utf8 path here, it will fail, but that's not realistically going to happen
let bytes = path_with_forward_slash.to_str().expect("found a non-UTF-8 path").as_bytes();

let encoded_filename = percent_encode(bytes, DEFAULT_ENCODE_SET);
println!("{}", encoded_filename.to_string());

Thanks for all the suggestions everyone!

2 Likes
12

Have you considered putting that code in a crate? It looks non-trivial to me!

13

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.