1use crate::ffi::OsStr;
2use crate::path::{Path, PathBuf, Prefix};
3use crate::{env, io};
4
5#[inline]
6pub fn is_sep_byte(b: u8) -> bool {
7 b == b'/'
8}
9
10#[inline]
11pub fn is_verbatim_sep(b: u8) -> bool {
12 b == b'/'
13}
14
15#[inline]
16pub fn parse_prefix(_: &OsStr) -> Option<Prefix<'_>> {
17 None
18}
19
20pub const MAIN_SEP_STR: &str = "/";
21pub const MAIN_SEP: char = '/';
22
23/// Make a POSIX path absolute without changing its semantics.
24pub(crate) fn absolute(path: &Path) -> io::Result<PathBuf> {
25 // This is mostly a wrapper around collecting `Path::components`, with
26 // exceptions made where this conflicts with the POSIX specification.
27 // See 4.13 Pathname Resolution, IEEE Std 1003.1-2017
28 // https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13
29
30 // Get the components, skipping the redundant leading "." component if it exists.
31 let mut components = path.strip_prefix(".").unwrap_or(path).components();
32 let path_os = path.as_os_str().as_encoded_bytes();
33
34 let mut normalized = if path.is_absolute() {
35 // "If a pathname begins with two successive <slash> characters, the
36 // first component following the leading <slash> characters may be
37 // interpreted in an implementation-defined manner, although more than
38 // two leading <slash> characters shall be treated as a single <slash>
39 // character."
40 if path_os.starts_with(b"//") && !path_os.starts_with(b"///") {
41 components.next();
42 PathBuf::from("//")
43 } else {
44 PathBuf::new()
45 }
46 } else {
47 env::current_dir()?
48 };
49 normalized.extend(components);
50
51 // "Interfaces using pathname resolution may specify additional constraints
52 // when a pathname that does not name an existing directory contains at
53 // least one non- <slash> character and contains one or more trailing
54 // <slash> characters".
55 // A trailing <slash> is also meaningful if "a symbolic link is
56 // encountered during pathname resolution".
57 if path_os.ends_with(b"/") {
58 normalized.push("");
59 }
60
61 Ok(normalized)
62}
63
64pub(crate) fn is_absolute(path: &Path) -> bool {
65 if cfg!(any(unix, target_os = "hermit", target_os = "wasi")) {
66 path.has_root()
67 } else {
68 path.has_root() && path.prefix().is_some()
69 }
70}
71