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fuchsia / third_party / rust / 5d6c49938e84c5af5b1c91cb570c995bb59ce1db / . / library / std / src / path.rs
blob: 62125f885b2ffe3995bf699574561d91280a61a5 [file] [log] [blame]
//! Cross-platform path manipulation.
//!
//! This module provides two types, [`PathBuf`] and [`Path`] (akin to [`String`]
//! and [`str`]), for working with paths abstractly. These types are thin wrappers
//! around [`OsString`] and [`OsStr`] respectively, meaning that they work directly
//! on strings according to the local platform's path syntax.
//!
//! Paths can be parsed into [`Component`]s by iterating over the structure
//! returned by the [`components`] method on [`Path`]. [`Component`]s roughly
//! correspond to the substrings between path separators (`/` or `\`). You can
//! reconstruct an equivalent path from components with the [`push`] method on
//! [`PathBuf`]; note that the paths may differ syntactically by the
//! normalization described in the documentation for the [`components`] method.
//!
//! ## Case sensitivity
//!
//! Unless otherwise indicated path methods that do not access the filesystem,
//! such as [`Path::starts_with`] and [`Path::ends_with`], are case sensitive no
//! matter the platform or filesystem. An exception to this is made for Windows
//! drive letters.
//!
//! ## Simple usage
//!
//! Path manipulation includes both parsing components from slices and building
//! new owned paths.
//!
//! To parse a path, you can create a [`Path`] slice from a [`str`]
//! slice and start asking questions:
//!
//! ```
//! use std::path::Path;
//! use std::ffi::OsStr;
//!
//! let path = Path::new("/tmp/foo/bar.txt");
//!
//! let parent = path.parent();
//! assert_eq!(parent, Some(Path::new("/tmp/foo")));
//!
//! let file_stem = path.file_stem();
//! assert_eq!(file_stem, Some(OsStr::new("bar")));
//!
//! let extension = path.extension();
//! assert_eq!(extension, Some(OsStr::new("txt")));
//! ```
//!
//! To build or modify paths, use [`PathBuf`]:
//!
//! ```
//! use std::path::PathBuf;
//!
//! // This way works...
//! let mut path = PathBuf::from("c:\\");
//!
//! path.push("windows");
//! path.push("system32");
//!
//! path.set_extension("dll");
//!
//! // ... but push is best used if you don't know everything up
//! // front. If you do, this way is better:
//! let path: PathBuf = ["c:\\", "windows", "system32.dll"].iter().collect();
//! ```
//!
//! [`components`]: Path::components
//! [`push`]: PathBuf::push
#![stable(feature = "rust1", since = "1.0.0")]
#![deny(unsafe_op_in_unsafe_fn)]
#[cfg(test)]
mod tests;
use core::clone::CloneToUninit;
use crate::borrow::{Borrow, Cow};
use crate::collections::TryReserveError;
use crate::error::Error;
use crate::ffi::{OsStr, OsString, os_str};
use crate::hash::{Hash, Hasher};
use crate::iter::FusedIterator;
use crate::ops::{self, Deref};
use crate::rc::Rc;
use crate::str::FromStr;
use crate::sync::Arc;
use crate::sys::path::{MAIN_SEP_STR, is_sep_byte, is_verbatim_sep, parse_prefix};
use crate::{cmp, fmt, fs, io, sys};
////////////////////////////////////////////////////////////////////////////////
// GENERAL NOTES
////////////////////////////////////////////////////////////////////////////////
//
// Parsing in this module is done by directly transmuting OsStr to [u8] slices,
// taking advantage of the fact that OsStr always encodes ASCII characters
// as-is. Eventually, this transmutation should be replaced by direct uses of
// OsStr APIs for parsing, but it will take a while for those to become
// available.
////////////////////////////////////////////////////////////////////////////////
// Windows Prefixes
////////////////////////////////////////////////////////////////////////////////
/// Windows path prefixes, e.g., `C:` or `\\server\share`.
///
/// Windows uses a variety of path prefix styles, including references to drive
/// volumes (like `C:`), network shared folders (like `\\server\share`), and
/// others. In addition, some path prefixes are "verbatim" (i.e., prefixed with
/// `\\?\`), in which case `/` is *not* treated as a separator and essentially
/// no normalization is performed.
///
/// # Examples
///
/// ```
/// use std::path::{Component, Path, Prefix};
/// use std::path::Prefix::*;
/// use std::ffi::OsStr;
///
/// fn get_path_prefix(s: &str) -> Prefix<'_> {
/// let path = Path::new(s);
/// match path.components().next().unwrap() {
/// Component::Prefix(prefix_component) => prefix_component.kind(),
/// _ => panic!(),
/// }
/// }
///
/// # if cfg!(windows) {
/// assert_eq!(Verbatim(OsStr::new("pictures")),
/// get_path_prefix(r"\\?\pictures\kittens"));
/// assert_eq!(VerbatimUNC(OsStr::new("server"), OsStr::new("share")),
/// get_path_prefix(r"\\?\UNC\server\share"));
/// assert_eq!(VerbatimDisk(b'C'), get_path_prefix(r"\\?\c:\"));
/// assert_eq!(DeviceNS(OsStr::new("BrainInterface")),
/// get_path_prefix(r"\\.\BrainInterface"));
/// assert_eq!(UNC(OsStr::new("server"), OsStr::new("share")),
/// get_path_prefix(r"\\server\share"));
/// assert_eq!(Disk(b'C'), get_path_prefix(r"C:\Users\Rust\Pictures\Ferris"));
/// # }
/// ```
#[derive(Copy, Clone, Debug, Hash, PartialOrd, Ord, PartialEq, Eq)]
#[stable(feature = "rust1", since = "1.0.0")]
pub enum Prefix<'a> {
/// Verbatim prefix, e.g., `\\?\cat_pics`.
///
/// Verbatim prefixes consist of `\\?\` immediately followed by the given
/// component.
#[stable(feature = "rust1", since = "1.0.0")]
Verbatim(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr),
/// Verbatim prefix using Windows' _**U**niform **N**aming **C**onvention_,
/// e.g., `\\?\UNC\server\share`.
///
/// Verbatim UNC prefixes consist of `\\?\UNC\` immediately followed by the
/// server's hostname and a share name.
#[stable(feature = "rust1", since = "1.0.0")]
VerbatimUNC(
#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
),
/// Verbatim disk prefix, e.g., `\\?\C:`.
///
/// Verbatim disk prefixes consist of `\\?\` immediately followed by the
/// drive letter and `:`.
#[stable(feature = "rust1", since = "1.0.0")]
VerbatimDisk(#[stable(feature = "rust1", since = "1.0.0")] u8),
/// Device namespace prefix, e.g., `\\.\COM42`.
///
/// Device namespace prefixes consist of `\\.\` (possibly using `/`
/// instead of `\`), immediately followed by the device name.
#[stable(feature = "rust1", since = "1.0.0")]
DeviceNS(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr),
/// Prefix using Windows' _**U**niform **N**aming **C**onvention_, e.g.
/// `\\server\share`.
///
/// UNC prefixes consist of the server's hostname and a share name.
#[stable(feature = "rust1", since = "1.0.0")]
UNC(
#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
),
/// Prefix `C:` for the given disk drive.
#[stable(feature = "rust1", since = "1.0.0")]
Disk(#[stable(feature = "rust1", since = "1.0.0")] u8),
}
impl<'a> Prefix<'a> {
#[inline]
fn len(&self) -> usize {
use self::Prefix::*;
fn os_str_len(s: &OsStr) -> usize {
s.as_encoded_bytes().len()
}
match *self {
Verbatim(x) => 4 + os_str_len(x),
VerbatimUNC(x, y) => {
8 + os_str_len(x) + if os_str_len(y) > 0 { 1 + os_str_len(y) } else { 0 }
}
VerbatimDisk(_) => 6,
UNC(x, y) => 2 + os_str_len(x) + if os_str_len(y) > 0 { 1 + os_str_len(y) } else { 0 },
DeviceNS(x) => 4 + os_str_len(x),
Disk(_) => 2,
}
}
/// Determines if the prefix is verbatim, i.e., begins with `\\?\`.
///
/// # Examples
///
/// ```
/// use std::path::Prefix::*;
/// use std::ffi::OsStr;
///
/// assert!(Verbatim(OsStr::new("pictures")).is_verbatim());
/// assert!(VerbatimUNC(OsStr::new("server"), OsStr::new("share")).is_verbatim());
/// assert!(VerbatimDisk(b'C').is_verbatim());
/// assert!(!DeviceNS(OsStr::new("BrainInterface")).is_verbatim());
/// assert!(!UNC(OsStr::new("server"), OsStr::new("share")).is_verbatim());
/// assert!(!Disk(b'C').is_verbatim());
/// ```
#[inline]
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_verbatim(&self) -> bool {
use self::Prefix::*;
matches!(*self, Verbatim(_) | VerbatimDisk(_) | VerbatimUNC(..))
}
#[inline]
fn is_drive(&self) -> bool {
matches!(*self, Prefix::Disk(_))
}
#[inline]
fn has_implicit_root(&self) -> bool {
!self.is_drive()
}
}
////////////////////////////////////////////////////////////////////////////////
// Exposed parsing helpers
////////////////////////////////////////////////////////////////////////////////
/// Determines whether the character is one of the permitted path
/// separators for the current platform.
///
/// # Examples
///
/// ```
/// use std::path;
///
/// assert!(path::is_separator('/')); // '/' works for both Unix and Windows
/// assert!(!path::is_separator('❤'));
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_separator(c: char) -> bool {
c.is_ascii() && is_sep_byte(c as u8)
}
/// The primary separator of path components for the current platform.
///
/// For example, `/` on Unix and `\` on Windows.
#[stable(feature = "rust1", since = "1.0.0")]
#[cfg_attr(not(test), rustc_diagnostic_item = "path_main_separator")]
pub const MAIN_SEPARATOR: char = crate::sys::path::MAIN_SEP;
/// The primary separator of path components for the current platform.
///
/// For example, `/` on Unix and `\` on Windows.
#[stable(feature = "main_separator_str", since = "1.68.0")]
pub const MAIN_SEPARATOR_STR: &str = crate::sys::path::MAIN_SEP_STR;
////////////////////////////////////////////////////////////////////////////////
// Misc helpers
////////////////////////////////////////////////////////////////////////////////
// Iterate through `iter` while it matches `prefix`; return `None` if `prefix`
// is not a prefix of `iter`, otherwise return `Some(iter_after_prefix)` giving
// `iter` after having exhausted `prefix`.
fn iter_after<'a, 'b, I, J>(mut iter: I, mut prefix: J) -> Option<I>
where
I: Iterator<Item = Component<'a>> + Clone,
J: Iterator<Item = Component<'b>>,
{
loop {
let mut iter_next = iter.clone();
match (iter_next.next(), prefix.next()) {
(Some(ref x), Some(ref y)) if x == y => (),
(Some(_), Some(_)) => return None,
(Some(_), None) => return Some(iter),
(None, None) => return Some(iter),
(None, Some(_)) => return None,
}
iter = iter_next;
}
}
// Detect scheme on Redox
fn has_redox_scheme(s: &[u8]) -> bool {
cfg!(target_os = "redox") && s.contains(&b':')
}
////////////////////////////////////////////////////////////////////////////////
// Cross-platform, iterator-independent parsing
////////////////////////////////////////////////////////////////////////////////
/// Says whether the first byte after the prefix is a separator.
fn has_physical_root(s: &[u8], prefix: Option<Prefix<'_>>) -> bool {
let path = if let Some(p) = prefix { &s[p.len()..] } else { s };
!path.is_empty() && is_sep_byte(path[0])
}
// basic workhorse for splitting stem and extension
fn rsplit_file_at_dot(file: &OsStr) -> (Option<&OsStr>, Option<&OsStr>) {
if file.as_encoded_bytes() == b".." {
return (Some(file), None);
}
// The unsafety here stems from converting between &OsStr and &[u8]
// and back. This is safe to do because (1) we only look at ASCII
// contents of the encoding and (2) new &OsStr values are produced
// only from ASCII-bounded slices of existing &OsStr values.
let mut iter = file.as_encoded_bytes().rsplitn(2, |b| *b == b'.');
let after = iter.next();
let before = iter.next();
if before == Some(b"") {
(Some(file), None)
} else {
unsafe {
(
before.map(|s| OsStr::from_encoded_bytes_unchecked(s)),
after.map(|s| OsStr::from_encoded_bytes_unchecked(s)),
)
}
}
}
fn split_file_at_dot(file: &OsStr) -> (&OsStr, Option<&OsStr>) {
let slice = file.as_encoded_bytes();
if slice == b".." {
return (file, None);
}
// The unsafety here stems from converting between &OsStr and &[u8]
// and back. This is safe to do because (1) we only look at ASCII
// contents of the encoding and (2) new &OsStr values are produced
// only from ASCII-bounded slices of existing &OsStr values.
let i = match slice[1..].iter().position(|b| *b == b'.') {
Some(i) => i + 1,
None => return (file, None),
};
let before = &slice[..i];
let after = &slice[i + 1..];
unsafe {
(
OsStr::from_encoded_bytes_unchecked(before),
Some(OsStr::from_encoded_bytes_unchecked(after)),
)
}
}
////////////////////////////////////////////////////////////////////////////////
// The core iterators
////////////////////////////////////////////////////////////////////////////////
/// Component parsing works by a double-ended state machine; the cursors at the
/// front and back of the path each keep track of what parts of the path have
/// been consumed so far.
///
/// Going front to back, a path is made up of a prefix, a starting
/// directory component, and a body (of normal components)
#[derive(Copy, Clone, PartialEq, PartialOrd, Debug)]
enum State {
Prefix = 0, // c:
StartDir = 1, // / or . or nothing
Body = 2, // foo/bar/baz
Done = 3,
}
/// A structure wrapping a Windows path prefix as well as its unparsed string
/// representation.
///
/// In addition to the parsed [`Prefix`] information returned by [`kind`],
/// `PrefixComponent` also holds the raw and unparsed [`OsStr`] slice,
/// returned by [`as_os_str`].
///
/// Instances of this `struct` can be obtained by matching against the
/// [`Prefix` variant] on [`Component`].
///
/// Does not occur on Unix.
///
/// # Examples
///
/// ```
/// # if cfg!(windows) {
/// use std::path::{Component, Path, Prefix};
/// use std::ffi::OsStr;
///
/// let path = Path::new(r"c:\you\later\");
/// match path.components().next().unwrap() {
/// Component::Prefix(prefix_component) => {
/// assert_eq!(Prefix::Disk(b'C'), prefix_component.kind());
/// assert_eq!(OsStr::new("c:"), prefix_component.as_os_str());
/// }
/// _ => unreachable!(),
/// }
/// # }
/// ```
///
/// [`as_os_str`]: PrefixComponent::as_os_str
/// [`kind`]: PrefixComponent::kind
/// [`Prefix` variant]: Component::Prefix
#[stable(feature = "rust1", since = "1.0.0")]
#[derive(Copy, Clone, Eq, Debug)]
pub struct PrefixComponent<'a> {
/// The prefix as an unparsed `OsStr` slice.
raw: &'a OsStr,
/// The parsed prefix data.
parsed: Prefix<'a>,
}
impl<'a> PrefixComponent<'a> {
/// Returns the parsed prefix data.
///
/// See [`Prefix`]'s documentation for more information on the different
/// kinds of prefixes.
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn kind(&self) -> Prefix<'a> {
self.parsed
}
/// Returns the raw [`OsStr`] slice for this prefix.
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn as_os_str(&self) -> &'a OsStr {
self.raw
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> PartialEq for PrefixComponent<'a> {
#[inline]
fn eq(&self, other: &PrefixComponent<'a>) -> bool {
self.parsed == other.parsed
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> PartialOrd for PrefixComponent<'a> {
#[inline]
fn partial_cmp(&self, other: &PrefixComponent<'a>) -> Option<cmp::Ordering> {
PartialOrd::partial_cmp(&self.parsed, &other.parsed)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Ord for PrefixComponent<'_> {
#[inline]
fn cmp(&self, other: &Self) -> cmp::Ordering {
Ord::cmp(&self.parsed, &other.parsed)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Hash for PrefixComponent<'_> {
fn hash<H: Hasher>(&self, h: &mut H) {
self.parsed.hash(h);
}
}
/// A single component of a path.
///
/// A `Component` roughly corresponds to a substring between path separators
/// (`/` or `\`).
///
/// This `enum` is created by iterating over [`Components`], which in turn is
/// created by the [`components`](Path::components) method on [`Path`].
///
/// # Examples
///
/// ```rust
/// use std::path::{Component, Path};
///
/// let path = Path::new("/tmp/foo/bar.txt");
/// let components = path.components().collect::<Vec<_>>();
/// assert_eq!(&components, &[
/// Component::RootDir,
/// Component::Normal("tmp".as_ref()),
/// Component::Normal("foo".as_ref()),
/// Component::Normal("bar.txt".as_ref()),
/// ]);
/// ```
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
#[stable(feature = "rust1", since = "1.0.0")]
pub enum Component<'a> {
/// A Windows path prefix, e.g., `C:` or `\\server\share`.
///
/// There is a large variety of prefix types, see [`Prefix`]'s documentation
/// for more.
///
/// Does not occur on Unix.
#[stable(feature = "rust1", since = "1.0.0")]
Prefix(#[stable(feature = "rust1", since = "1.0.0")] PrefixComponent<'a>),
/// The root directory component, appears after any prefix and before anything else.
///
/// It represents a separator that designates that a path starts from root.
#[stable(feature = "rust1", since = "1.0.0")]
RootDir,
/// A reference to the current directory, i.e., `.`.
#[stable(feature = "rust1", since = "1.0.0")]
CurDir,
/// A reference to the parent directory, i.e., `..`.
#[stable(feature = "rust1", since = "1.0.0")]
ParentDir,
/// A normal component, e.g., `a` and `b` in `a/b`.
///
/// This variant is the most common one, it represents references to files
/// or directories.
#[stable(feature = "rust1", since = "1.0.0")]
Normal(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr),
}
impl<'a> Component<'a> {
/// Extracts the underlying [`OsStr`] slice.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("./tmp/foo/bar.txt");
/// let components: Vec<_> = path.components().map(|comp| comp.as_os_str()).collect();
/// assert_eq!(&components, &[".", "tmp", "foo", "bar.txt"]);
/// ```
#[must_use = "`self` will be dropped if the result is not used"]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn as_os_str(self) -> &'a OsStr {
match self {
Component::Prefix(p) => p.as_os_str(),
Component::RootDir => OsStr::new(MAIN_SEP_STR),
Component::CurDir => OsStr::new("."),
Component::ParentDir => OsStr::new(".."),
Component::Normal(path) => path,
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<OsStr> for Component<'_> {
#[inline]
fn as_ref(&self) -> &OsStr {
self.as_os_str()
}
}
#[stable(feature = "path_component_asref", since = "1.25.0")]
impl AsRef<Path> for Component<'_> {
#[inline]
fn as_ref(&self) -> &Path {
self.as_os_str().as_ref()
}
}
/// An iterator over the [`Component`]s of a [`Path`].
///
/// This `struct` is created by the [`components`] method on [`Path`].
/// See its documentation for more.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/tmp/foo/bar.txt");
///
/// for component in path.components() {
/// println!("{component:?}");
/// }
/// ```
///
/// [`components`]: Path::components
#[derive(Clone)]
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Components<'a> {
// The path left to parse components from
path: &'a [u8],
// The prefix as it was originally parsed, if any
prefix: Option<Prefix<'a>>,
// true if path *physically* has a root separator; for most Windows
// prefixes, it may have a "logical" root separator for the purposes of
// normalization, e.g., \\server\share == \\server\share\.
has_physical_root: bool,
// The iterator is double-ended, and these two states keep track of what has
// been produced from either end
front: State,
back: State,
}
/// An iterator over the [`Component`]s of a [`Path`], as [`OsStr`] slices.
///
/// This `struct` is created by the [`iter`] method on [`Path`].
/// See its documentation for more.
///
/// [`iter`]: Path::iter
#[derive(Clone)]
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Iter<'a> {
inner: Components<'a>,
}
#[stable(feature = "path_components_debug", since = "1.13.0")]
impl fmt::Debug for Components<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
struct DebugHelper<'a>(&'a Path);
impl fmt::Debug for DebugHelper<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.0.components()).finish()
}
}
f.debug_tuple("Components").field(&DebugHelper(self.as_path())).finish()
}
}
impl<'a> Components<'a> {
// how long is the prefix, if any?
#[inline]
fn prefix_len(&self) -> usize {
self.prefix.as_ref().map(Prefix::len).unwrap_or(0)
}
#[inline]
fn prefix_verbatim(&self) -> bool {
self.prefix.as_ref().map(Prefix::is_verbatim).unwrap_or(false)
}
/// how much of the prefix is left from the point of view of iteration?
#[inline]
fn prefix_remaining(&self) -> usize {
if self.front == State::Prefix { self.prefix_len() } else { 0 }
}
// Given the iteration so far, how much of the pre-State::Body path is left?
#[inline]
fn len_before_body(&self) -> usize {
let root = if self.front <= State::StartDir && self.has_physical_root { 1 } else { 0 };
let cur_dir = if self.front <= State::StartDir && self.include_cur_dir() { 1 } else { 0 };
self.prefix_remaining() + root + cur_dir
}
// is the iteration complete?
#[inline]
fn finished(&self) -> bool {
self.front == State::Done || self.back == State::Done || self.front > self.back
}
#[inline]
fn is_sep_byte(&self, b: u8) -> bool {
if self.prefix_verbatim() { is_verbatim_sep(b) } else { is_sep_byte(b) }
}
/// Extracts a slice corresponding to the portion of the path remaining for iteration.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let mut components = Path::new("/tmp/foo/bar.txt").components();
/// components.next();
/// components.next();
///
/// assert_eq!(Path::new("foo/bar.txt"), components.as_path());
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn as_path(&self) -> &'a Path {
let mut comps = self.clone();
if comps.front == State::Body {
comps.trim_left();
}
if comps.back == State::Body {
comps.trim_right();
}
unsafe { Path::from_u8_slice(comps.path) }
}
/// Is the *original* path rooted?
fn has_root(&self) -> bool {
if self.has_physical_root {
return true;
}
if let Some(p) = self.prefix {
if p.has_implicit_root() {
return true;
}
}
false
}
/// Should the normalized path include a leading . ?
fn include_cur_dir(&self) -> bool {
if self.has_root() {
return false;
}
let mut iter = self.path[self.prefix_remaining()..].iter();
match (iter.next(), iter.next()) {
(Some(&b'.'), None) => true,
(Some(&b'.'), Some(&b)) => self.is_sep_byte(b),
_ => false,
}
}
// parse a given byte sequence following the OsStr encoding into the
// corresponding path component
unsafe fn parse_single_component<'b>(&self, comp: &'b [u8]) -> Option<Component<'b>> {
match comp {
b"." if self.prefix_verbatim() => Some(Component::CurDir),
b"." => None, // . components are normalized away, except at
// the beginning of a path, which is treated
// separately via `include_cur_dir`
b".." => Some(Component::ParentDir),
b"" => None,
_ => Some(Component::Normal(unsafe { OsStr::from_encoded_bytes_unchecked(comp) })),
}
}
// parse a component from the left, saying how many bytes to consume to
// remove the component
fn parse_next_component(&self) -> (usize, Option<Component<'a>>) {
debug_assert!(self.front == State::Body);
let (extra, comp) = match self.path.iter().position(|b| self.is_sep_byte(*b)) {
None => (0, self.path),
Some(i) => (1, &self.path[..i]),
};
// SAFETY: `comp` is a valid substring, since it is split on a separator.
(comp.len() + extra, unsafe { self.parse_single_component(comp) })
}
// parse a component from the right, saying how many bytes to consume to
// remove the component
fn parse_next_component_back(&self) -> (usize, Option<Component<'a>>) {
debug_assert!(self.back == State::Body);
let start = self.len_before_body();
let (extra, comp) = match self.path[start..].iter().rposition(|b| self.is_sep_byte(*b)) {
None => (0, &self.path[start..]),
Some(i) => (1, &self.path[start + i + 1..]),
};
// SAFETY: `comp` is a valid substring, since it is split on a separator.
(comp.len() + extra, unsafe { self.parse_single_component(comp) })
}
// trim away repeated separators (i.e., empty components) on the left
fn trim_left(&mut self) {
while !self.path.is_empty() {
let (size, comp) = self.parse_next_component();
if comp.is_some() {
return;
} else {
self.path = &self.path[size..];
}
}
}
// trim away repeated separators (i.e., empty components) on the right
fn trim_right(&mut self) {
while self.path.len() > self.len_before_body() {
let (size, comp) = self.parse_next_component_back();
if comp.is_some() {
return;
} else {
self.path = &self.path[..self.path.len() - size];
}
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for Components<'_> {
#[inline]
fn as_ref(&self) -> &Path {
self.as_path()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<OsStr> for Components<'_> {
#[inline]
fn as_ref(&self) -> &OsStr {
self.as_path().as_os_str()
}
}
#[stable(feature = "path_iter_debug", since = "1.13.0")]
impl fmt::Debug for Iter<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
struct DebugHelper<'a>(&'a Path);
impl fmt::Debug for DebugHelper<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.0.iter()).finish()
}
}
f.debug_tuple("Iter").field(&DebugHelper(self.as_path())).finish()
}
}
impl<'a> Iter<'a> {
/// Extracts a slice corresponding to the portion of the path remaining for iteration.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let mut iter = Path::new("/tmp/foo/bar.txt").iter();
/// iter.next();
/// iter.next();
///
/// assert_eq!(Path::new("foo/bar.txt"), iter.as_path());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn as_path(&self) -> &'a Path {
self.inner.as_path()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for Iter<'_> {
#[inline]
fn as_ref(&self) -> &Path {
self.as_path()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<OsStr> for Iter<'_> {
#[inline]
fn as_ref(&self) -> &OsStr {
self.as_path().as_os_str()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Iter<'a> {
type Item = &'a OsStr;
#[inline]
fn next(&mut self) -> Option<&'a OsStr> {
self.inner.next().map(Component::as_os_str)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> DoubleEndedIterator for Iter<'a> {
#[inline]
fn next_back(&mut self) -> Option<&'a OsStr> {
self.inner.next_back().map(Component::as_os_str)
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for Iter<'_> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> Iterator for Components<'a> {
type Item = Component<'a>;
fn next(&mut self) -> Option<Component<'a>> {
while !self.finished() {
match self.front {
State::Prefix if self.prefix_len() > 0 => {
self.front = State::StartDir;
debug_assert!(self.prefix_len() <= self.path.len());
let raw = &self.path[..self.prefix_len()];
self.path = &self.path[self.prefix_len()..];
return Some(Component::Prefix(PrefixComponent {
raw: unsafe { OsStr::from_encoded_bytes_unchecked(raw) },
parsed: self.prefix.unwrap(),
}));
}
State::Prefix => {
self.front = State::StartDir;
}
State::StartDir => {
self.front = State::Body;
if self.has_physical_root {
debug_assert!(!self.path.is_empty());
self.path = &self.path[1..];
return Some(Component::RootDir);
} else if let Some(p) = self.prefix {
if p.has_implicit_root() && !p.is_verbatim() {
return Some(Component::RootDir);
}
} else if self.include_cur_dir() {
debug_assert!(!self.path.is_empty());
self.path = &self.path[1..];
return Some(Component::CurDir);
}
}
State::Body if !self.path.is_empty() => {
let (size, comp) = self.parse_next_component();
self.path = &self.path[size..];
if comp.is_some() {
return comp;
}
}
State::Body => {
self.front = State::Done;
}
State::Done => unreachable!(),
}
}
None
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> DoubleEndedIterator for Components<'a> {
fn next_back(&mut self) -> Option<Component<'a>> {
while !self.finished() {
match self.back {
State::Body if self.path.len() > self.len_before_body() => {
let (size, comp) = self.parse_next_component_back();
self.path = &self.path[..self.path.len() - size];
if comp.is_some() {
return comp;
}
}
State::Body => {
self.back = State::StartDir;
}
State::StartDir => {
self.back = State::Prefix;
if self.has_physical_root {
self.path = &self.path[..self.path.len() - 1];
return Some(Component::RootDir);
} else if let Some(p) = self.prefix {
if p.has_implicit_root() && !p.is_verbatim() {
return Some(Component::RootDir);
}
} else if self.include_cur_dir() {
self.path = &self.path[..self.path.len() - 1];
return Some(Component::CurDir);
}
}
State::Prefix if self.prefix_len() > 0 => {
self.back = State::Done;
return Some(Component::Prefix(PrefixComponent {
raw: unsafe { OsStr::from_encoded_bytes_unchecked(self.path) },
parsed: self.prefix.unwrap(),
}));
}
State::Prefix => {
self.back = State::Done;
return None;
}
State::Done => unreachable!(),
}
}
None
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for Components<'_> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> PartialEq for Components<'a> {
#[inline]
fn eq(&self, other: &Components<'a>) -> bool {
let Components { path: _, front: _, back: _, has_physical_root: _, prefix: _ } = self;
// Fast path for exact matches, e.g. for hashmap lookups.
// Don't explicitly compare the prefix or has_physical_root fields since they'll
// either be covered by the `path` buffer or are only relevant for `prefix_verbatim()`.
if self.path.len() == other.path.len()
&& self.front == other.front
&& self.back == State::Body
&& other.back == State::Body
&& self.prefix_verbatim() == other.prefix_verbatim()
{
// possible future improvement: this could bail out earlier if there were a
// reverse memcmp/bcmp comparing back to front
if self.path == other.path {
return true;
}
}
// compare back to front since absolute paths often share long prefixes
Iterator::eq(self.clone().rev(), other.clone().rev())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Eq for Components<'_> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> PartialOrd for Components<'a> {
#[inline]
fn partial_cmp(&self, other: &Components<'a>) -> Option<cmp::Ordering> {
Some(compare_components(self.clone(), other.clone()))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Ord for Components<'_> {
#[inline]
fn cmp(&self, other: &Self) -> cmp::Ordering {
compare_components(self.clone(), other.clone())
}
}
fn compare_components(mut left: Components<'_>, mut right: Components<'_>) -> cmp::Ordering {
// Fast path for long shared prefixes
//
// - compare raw bytes to find first mismatch
// - backtrack to find separator before mismatch to avoid ambiguous parsings of '.' or '..' characters
// - if found update state to only do a component-wise comparison on the remainder,
// otherwise do it on the full path
//
// The fast path isn't taken for paths with a PrefixComponent to avoid backtracking into
// the middle of one
if left.prefix.is_none() && right.prefix.is_none() && left.front == right.front {
// possible future improvement: a [u8]::first_mismatch simd implementation
let first_difference = match left.path.iter().zip(right.path).position(|(&a, &b)| a != b) {
None if left.path.len() == right.path.len() => return cmp::Ordering::Equal,
None => left.path.len().min(right.path.len()),
Some(diff) => diff,
};
if let Some(previous_sep) =
left.path[..first_difference].iter().rposition(|&b| left.is_sep_byte(b))
{
let mismatched_component_start = previous_sep + 1;
left.path = &left.path[mismatched_component_start..];
left.front = State::Body;
right.path = &right.path[mismatched_component_start..];
right.front = State::Body;
}
}
Iterator::cmp(left, right)
}
/// An iterator over [`Path`] and its ancestors.
///
/// This `struct` is created by the [`ancestors`] method on [`Path`].
/// See its documentation for more.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/foo/bar");
///
/// for ancestor in path.ancestors() {
/// println!("{}", ancestor.display());
/// }
/// ```
///
/// [`ancestors`]: Path::ancestors
#[derive(Copy, Clone, Debug)]
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "path_ancestors", since = "1.28.0")]
pub struct Ancestors<'a> {
next: Option<&'a Path>,
}
#[stable(feature = "path_ancestors", since = "1.28.0")]
impl<'a> Iterator for Ancestors<'a> {
type Item = &'a Path;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
let next = self.next;
self.next = next.and_then(Path::parent);
next
}
}
#[stable(feature = "path_ancestors", since = "1.28.0")]
impl FusedIterator for Ancestors<'_> {}
////////////////////////////////////////////////////////////////////////////////
// Basic types and traits
////////////////////////////////////////////////////////////////////////////////
/// An owned, mutable path (akin to [`String`]).
///
/// This type provides methods like [`push`] and [`set_extension`] that mutate
/// the path in place. It also implements [`Deref`] to [`Path`], meaning that
/// all methods on [`Path`] slices are available on `PathBuf` values as well.
///
/// [`push`]: PathBuf::push
/// [`set_extension`]: PathBuf::set_extension
///
/// More details about the overall approach can be found in
/// the [module documentation](self).
///
/// # Examples
///
/// You can use [`push`] to build up a `PathBuf` from
/// components:
///
/// ```
/// use std::path::PathBuf;
///
/// let mut path = PathBuf::new();
///
/// path.push(r"C:\");
/// path.push("windows");
/// path.push("system32");
///
/// path.set_extension("dll");
/// ```
///
/// However, [`push`] is best used for dynamic situations. This is a better way
/// to do this when you know all of the components ahead of time:
///
/// ```
/// use std::path::PathBuf;
///
/// let path: PathBuf = [r"C:\", "windows", "system32.dll"].iter().collect();
/// ```
///
/// We can still do better than this! Since these are all strings, we can use
/// `From::from`:
///
/// ```
/// use std::path::PathBuf;
///
/// let path = PathBuf::from(r"C:\windows\system32.dll");
/// ```
///
/// Which method works best depends on what kind of situation you're in.
///
/// Note that `PathBuf` does not always sanitize arguments, for example
/// [`push`] allows paths built from strings which include separators:
///
/// use std::path::PathBuf;
///
/// let mut path = PathBuf::new();
///
/// path.push(r"C:\");
/// path.push("windows");
/// path.push(r"..\otherdir");
/// path.push("system32");
///
/// The behavior of `PathBuf` may be changed to a panic on such inputs
/// in the future. [`Extend::extend`] should be used to add multi-part paths.
#[cfg_attr(not(test), rustc_diagnostic_item = "PathBuf")]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct PathBuf {
inner: OsString,
}
impl PathBuf {
/// Allocates an empty `PathBuf`.
///
/// # Examples
///
/// ```
/// use std::path::PathBuf;
///
/// let path = PathBuf::new();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn new() -> PathBuf {
PathBuf { inner: OsString::new() }
}
/// Creates a new `PathBuf` with a given capacity used to create the
/// internal [`OsString`]. See [`with_capacity`] defined on [`OsString`].
///
/// # Examples
///
/// ```
/// use std::path::PathBuf;
///
/// let mut path = PathBuf::with_capacity(10);
/// let capacity = path.capacity();
///
/// // This push is done without reallocating
/// path.push(r"C:\");
///
/// assert_eq!(capacity, path.capacity());
/// ```
///
/// [`with_capacity`]: OsString::with_capacity
#[stable(feature = "path_buf_capacity", since = "1.44.0")]
#[must_use]
#[inline]
pub fn with_capacity(capacity: usize) -> PathBuf {
PathBuf { inner: OsString::with_capacity(capacity) }
}
/// Coerces to a [`Path`] slice.
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let p = PathBuf::from("/test");
/// assert_eq!(Path::new("/test"), p.as_path());
/// ```
#[cfg_attr(not(test), rustc_diagnostic_item = "pathbuf_as_path")]
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn as_path(&self) -> &Path {
self
}
/// Consumes and leaks the `PathBuf`, returning a mutable reference to the contents,
/// `&'a mut Path`.
///
/// The caller has free choice over the returned lifetime, including 'static.
/// Indeed, this function is ideally used for data that lives for the remainder of
/// the program’s life, as dropping the returned reference will cause a memory leak.
///
/// It does not reallocate or shrink the `PathBuf`, so the leaked allocation may include
/// unused capacity that is not part of the returned slice. If you want to discard excess
/// capacity, call [`into_boxed_path`], and then [`Box::leak`] instead.
/// However, keep in mind that trimming the capacity may result in a reallocation and copy.
///
/// [`into_boxed_path`]: Self::into_boxed_path
#[unstable(feature = "os_string_pathbuf_leak", issue = "125965")]
#[inline]
pub fn leak<'a>(self) -> &'a mut Path {
Path::from_inner_mut(self.inner.leak())
}
/// Extends `self` with `path`.
///
/// If `path` is absolute, it replaces the current path.
///
/// On Windows:
///
/// * if `path` has a root but no prefix (e.g., `\windows`), it
/// replaces everything except for the prefix (if any) of `self`.
/// * if `path` has a prefix but no root, it replaces `self`.
/// * if `self` has a verbatim prefix (e.g. `\\?\C:\windows`)
/// and `path` is not empty, the new path is normalized: all references
/// to `.` and `..` are removed.
///
/// Consider using [`Path::join`] if you need a new `PathBuf` instead of
/// using this function on a cloned `PathBuf`.
///
/// # Examples
///
/// Pushing a relative path extends the existing path:
///
/// ```
/// use std::path::PathBuf;
///
/// let mut path = PathBuf::from("/tmp");
/// path.push("file.bk");
/// assert_eq!(path, PathBuf::from("/tmp/file.bk"));
/// ```
///
/// Pushing an absolute path replaces the existing path:
///
/// ```
/// use std::path::PathBuf;
///
/// let mut path = PathBuf::from("/tmp");
/// path.push("/etc");
/// assert_eq!(path, PathBuf::from("/etc"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_confusables("append", "put")]
pub fn push<P: AsRef<Path>>(&mut self, path: P) {
self._push(path.as_ref())
}
fn _push(&mut self, path: &Path) {
// in general, a separator is needed if the rightmost byte is not a separator
let buf = self.inner.as_encoded_bytes();
let mut need_sep = buf.last().map(|c| !is_sep_byte(*c)).unwrap_or(false);
// in the special case of `C:` on Windows, do *not* add a separator
let comps = self.components();
if comps.prefix_len() > 0
&& comps.prefix_len() == comps.path.len()
&& comps.prefix.unwrap().is_drive()
{
need_sep = false
}
// absolute `path` replaces `self`
if path.is_absolute() || path.prefix().is_some() {
self.inner.truncate(0);
// verbatim paths need . and .. removed
} else if comps.prefix_verbatim() && !path.inner.is_empty() {
let mut buf: Vec<_> = comps.collect();
for c in path.components() {
match c {
Component::RootDir => {
buf.truncate(1);
buf.push(c);
}
Component::CurDir => (),
Component::ParentDir => {
if let Some(Component::Normal(_)) = buf.last() {
buf.pop();
}
}
_ => buf.push(c),
}
}
let mut res = OsString::new();
let mut need_sep = false;
for c in buf {
if need_sep && c != Component::RootDir {
res.push(MAIN_SEP_STR);
}
res.push(c.as_os_str());
need_sep = match c {
Component::RootDir => false,
Component::Prefix(prefix) => {
!prefix.parsed.is_drive() && prefix.parsed.len() > 0
}
_ => true,
}
}
self.inner = res;
return;
// `path` has a root but no prefix, e.g., `\windows` (Windows only)
} else if path.has_root() {
let prefix_len = self.components().prefix_remaining();
self.inner.truncate(prefix_len);
// `path` is a pure relative path
} else if need_sep {
self.inner.push(MAIN_SEP_STR);
}
self.inner.push(path);
}
/// Truncates `self` to [`self.parent`].
///
/// Returns `false` and does nothing if [`self.parent`] is [`None`].
/// Otherwise, returns `true`.
///
/// [`self.parent`]: Path::parent
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let mut p = PathBuf::from("/spirited/away.rs");
///
/// p.pop();
/// assert_eq!(Path::new("/spirited"), p);
/// p.pop();
/// assert_eq!(Path::new("/"), p);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn pop(&mut self) -> bool {
match self.parent().map(|p| p.as_u8_slice().len()) {
Some(len) => {
self.inner.truncate(len);
true
}
None => false,
}
}
/// Updates [`self.file_name`] to `file_name`.
///
/// If [`self.file_name`] was [`None`], this is equivalent to pushing
/// `file_name`.
///
/// Otherwise it is equivalent to calling [`pop`] and then pushing
/// `file_name`. The new path will be a sibling of the original path.
/// (That is, it will have the same parent.)
///
/// The argument is not sanitized, so can include separators. This
/// behavior may be changed to a panic in the future.
///
/// [`self.file_name`]: Path::file_name
/// [`pop`]: PathBuf::pop
///
/// # Examples
///
/// ```
/// use std::path::PathBuf;
///
/// let mut buf = PathBuf::from("/");
/// assert!(buf.file_name() == None);
///
/// buf.set_file_name("foo.txt");
/// assert!(buf == PathBuf::from("/foo.txt"));
/// assert!(buf.file_name().is_some());
///
/// buf.set_file_name("bar.txt");
/// assert!(buf == PathBuf::from("/bar.txt"));
///
/// buf.set_file_name("baz");
/// assert!(buf == PathBuf::from("/baz"));
///
/// buf.set_file_name("../b/c.txt");
/// assert!(buf == PathBuf::from("/../b/c.txt"));
///
/// buf.set_file_name("baz");
/// assert!(buf == PathBuf::from("/../b/baz"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn set_file_name<S: AsRef<OsStr>>(&mut self, file_name: S) {
self._set_file_name(file_name.as_ref())
}
fn _set_file_name(&mut self, file_name: &OsStr) {
if self.file_name().is_some() {
let popped = self.pop();
debug_assert!(popped);
}
self.push(file_name);
}
/// Updates [`self.extension`] to `Some(extension)` or to `None` if
/// `extension` is empty.
///
/// Returns `false` and does nothing if [`self.file_name`] is [`None`],
/// returns `true` and updates the extension otherwise.
///
/// If [`self.extension`] is [`None`], the extension is added; otherwise
/// it is replaced.
///
/// If `extension` is the empty string, [`self.extension`] will be [`None`]
/// afterwards, not `Some("")`.
///
/// # Panics
///
/// Panics if the passed extension contains a path separator (see
/// [`is_separator`]).
///
/// # Caveats
///
/// The new `extension` may contain dots and will be used in its entirety,
/// but only the part after the final dot will be reflected in
/// [`self.extension`].
///
/// If the file stem contains internal dots and `extension` is empty, part
/// of the old file stem will be considered the new [`self.extension`].
///
/// See the examples below.
///
/// [`self.file_name`]: Path::file_name
/// [`self.extension`]: Path::extension
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let mut p = PathBuf::from("/feel/the");
///
/// p.set_extension("force");
/// assert_eq!(Path::new("/feel/the.force"), p.as_path());
///
/// p.set_extension("dark.side");
/// assert_eq!(Path::new("/feel/the.dark.side"), p.as_path());
///
/// p.set_extension("cookie");
/// assert_eq!(Path::new("/feel/the.dark.cookie"), p.as_path());
///
/// p.set_extension("");
/// assert_eq!(Path::new("/feel/the.dark"), p.as_path());
///
/// p.set_extension("");
/// assert_eq!(Path::new("/feel/the"), p.as_path());
///
/// p.set_extension("");
/// assert_eq!(Path::new("/feel/the"), p.as_path());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn set_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> bool {
self._set_extension(extension.as_ref())
}
fn _set_extension(&mut self, extension: &OsStr) -> bool {
for &b in extension.as_encoded_bytes() {
if b < 128 {
if is_separator(b as char) {
panic!("extension cannot contain path separators: {:?}", extension);
}
}
}
let file_stem = match self.file_stem() {
None => return false,
Some(f) => f.as_encoded_bytes(),
};
// truncate until right after the file stem
let end_file_stem = file_stem[file_stem.len()..].as_ptr().addr();
let start = self.inner.as_encoded_bytes().as_ptr().addr();
self.inner.truncate(end_file_stem.wrapping_sub(start));
// add the new extension, if any
let new = extension;
if !new.is_empty() {
self.inner.reserve_exact(new.len() + 1);
self.inner.push(OsStr::new("."));
self.inner.push(new);
}
true
}
/// Append [`self.extension`] with `extension`.
///
/// Returns `false` and does nothing if [`self.file_name`] is [`None`],
/// returns `true` and updates the extension otherwise.
///
/// # Caveats
///
/// The appended `extension` may contain dots and will be used in its entirety,
/// but only the part after the final dot will be reflected in
/// [`self.extension`].
///
/// See the examples below.
///
/// [`self.file_name`]: Path::file_name
/// [`self.extension`]: Path::extension
///
/// # Examples
///
/// ```
/// #![feature(path_add_extension)]
///
/// use std::path::{Path, PathBuf};
///
/// let mut p = PathBuf::from("/feel/the");
///
/// p.add_extension("formatted");
/// assert_eq!(Path::new("/feel/the.formatted"), p.as_path());
///
/// p.add_extension("dark.side");
/// assert_eq!(Path::new("/feel/the.formatted.dark.side"), p.as_path());
///
/// p.set_extension("cookie");
/// assert_eq!(Path::new("/feel/the.formatted.dark.cookie"), p.as_path());
///
/// p.set_extension("");
/// assert_eq!(Path::new("/feel/the.formatted.dark"), p.as_path());
///
/// p.add_extension("");
/// assert_eq!(Path::new("/feel/the.formatted.dark"), p.as_path());
/// ```
#[unstable(feature = "path_add_extension", issue = "127292")]
pub fn add_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> bool {
self._add_extension(extension.as_ref())
}
fn _add_extension(&mut self, extension: &OsStr) -> bool {
let file_name = match self.file_name() {
None => return false,
Some(f) => f.as_encoded_bytes(),
};
let new = extension;
if !new.is_empty() {
// truncate until right after the file name
// this is necessary for trimming the trailing slash
let end_file_name = file_name[file_name.len()..].as_ptr().addr();
let start = self.inner.as_encoded_bytes().as_ptr().addr();
self.inner.truncate(end_file_name.wrapping_sub(start));
// append the new extension
self.inner.reserve_exact(new.len() + 1);
self.inner.push(OsStr::new("."));
self.inner.push(new);
}
true
}
/// Yields a mutable reference to the underlying [`OsString`] instance.
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let mut path = PathBuf::from("/foo");
///
/// path.push("bar");
/// assert_eq!(path, Path::new("/foo/bar"));
///
/// // OsString's `push` does not add a separator.
/// path.as_mut_os_string().push("baz");
/// assert_eq!(path, Path::new("/foo/barbaz"));
/// ```
#[stable(feature = "path_as_mut_os_str", since = "1.70.0")]
#[must_use]
#[inline]
pub fn as_mut_os_string(&mut self) -> &mut OsString {
&mut self.inner
}
/// Consumes the `PathBuf`, yielding its internal [`OsString`] storage.
///
/// # Examples
///
/// ```
/// use std::path::PathBuf;
///
/// let p = PathBuf::from("/the/head");
/// let os_str = p.into_os_string();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use = "`self` will be dropped if the result is not used"]
#[inline]
pub fn into_os_string(self) -> OsString {
self.inner
}
/// Converts this `PathBuf` into a [boxed](Box) [`Path`].
#[stable(feature = "into_boxed_path", since = "1.20.0")]
#[must_use = "`self` will be dropped if the result is not used"]
#[inline]
pub fn into_boxed_path(self) -> Box<Path> {
let rw = Box::into_raw(self.inner.into_boxed_os_str()) as *mut Path;
unsafe { Box::from_raw(rw) }
}
/// Invokes [`capacity`] on the underlying instance of [`OsString`].
///
/// [`capacity`]: OsString::capacity
#[stable(feature = "path_buf_capacity", since = "1.44.0")]
#[must_use]
#[inline]
pub fn capacity(&self) -> usize {
self.inner.capacity()
}
/// Invokes [`clear`] on the underlying instance of [`OsString`].
///
/// [`clear`]: OsString::clear
#[stable(feature = "path_buf_capacity", since = "1.44.0")]
#[inline]
pub fn clear(&mut self) {
self.inner.clear()
}
/// Invokes [`reserve`] on the underlying instance of [`OsString`].
///
/// [`reserve`]: OsString::reserve
#[stable(feature = "path_buf_capacity", since = "1.44.0")]
#[inline]
pub fn reserve(&mut self, additional: usize) {
self.inner.reserve(additional)
}
/// Invokes [`try_reserve`] on the underlying instance of [`OsString`].
///
/// [`try_reserve`]: OsString::try_reserve
#[stable(feature = "try_reserve_2", since = "1.63.0")]
#[inline]
pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
self.inner.try_reserve(additional)
}
/// Invokes [`reserve_exact`] on the underlying instance of [`OsString`].
///
/// [`reserve_exact`]: OsString::reserve_exact
#[stable(feature = "path_buf_capacity", since = "1.44.0")]
#[inline]
pub fn reserve_exact(&mut self, additional: usize) {
self.inner.reserve_exact(additional)
}
/// Invokes [`try_reserve_exact`] on the underlying instance of [`OsString`].
///
/// [`try_reserve_exact`]: OsString::try_reserve_exact
#[stable(feature = "try_reserve_2", since = "1.63.0")]
#[inline]
pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError> {
self.inner.try_reserve_exact(additional)
}
/// Invokes [`shrink_to_fit`] on the underlying instance of [`OsString`].
///
/// [`shrink_to_fit`]: OsString::shrink_to_fit
#[stable(feature = "path_buf_capacity", since = "1.44.0")]
#[inline]
pub fn shrink_to_fit(&mut self) {
self.inner.shrink_to_fit()
}
/// Invokes [`shrink_to`] on the underlying instance of [`OsString`].
///
/// [`shrink_to`]: OsString::shrink_to
#[stable(feature = "shrink_to", since = "1.56.0")]
#[inline]
pub fn shrink_to(&mut self, min_capacity: usize) {
self.inner.shrink_to(min_capacity)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Clone for PathBuf {
#[inline]
fn clone(&self) -> Self {
PathBuf { inner: self.inner.clone() }
}
/// Clones the contents of `source` into `self`.
///
/// This method is preferred over simply assigning `source.clone()` to `self`,
/// as it avoids reallocation if possible.
#[inline]
fn clone_from(&mut self, source: &Self) {
self.inner.clone_from(&source.inner)
}
}
#[stable(feature = "box_from_path", since = "1.17.0")]
impl From<&Path> for Box<Path> {
/// Creates a boxed [`Path`] from a reference.
///
/// This will allocate and clone `path` to it.
fn from(path: &Path) -> Box<Path> {
let boxed: Box<OsStr> = path.inner.into();
let rw = Box::into_raw(boxed) as *mut Path;
unsafe { Box::from_raw(rw) }
}
}
#[stable(feature = "box_from_cow", since = "1.45.0")]
impl From<Cow<'_, Path>> for Box<Path> {
/// Creates a boxed [`Path`] from a clone-on-write pointer.
///
/// Converting from a `Cow::Owned` does not clone or allocate.
#[inline]
fn from(cow: Cow<'_, Path>) -> Box<Path> {
match cow {
Cow::Borrowed(path) => Box::from(path),
Cow::Owned(path) => Box::from(path),
}
}
}
#[stable(feature = "path_buf_from_box", since = "1.18.0")]
impl From<Box<Path>> for PathBuf {
/// Converts a <code>[Box]&lt;[Path]&gt;</code> into a [`PathBuf`].
///
/// This conversion does not allocate or copy memory.
#[inline]
fn from(boxed: Box<Path>) -> PathBuf {
boxed.into_path_buf()
}
}
#[stable(feature = "box_from_path_buf", since = "1.20.0")]
impl From<PathBuf> for Box<Path> {
/// Converts a [`PathBuf`] into a <code>[Box]&lt;[Path]&gt;</code>.
///
/// This conversion currently should not allocate memory,
/// but this behavior is not guaranteed on all platforms or in all future versions.
#[inline]
fn from(p: PathBuf) -> Box<Path> {
p.into_boxed_path()
}
}
#[stable(feature = "more_box_slice_clone", since = "1.29.0")]
impl Clone for Box<Path> {
#[inline]
fn clone(&self) -> Self {
self.to_path_buf().into_boxed_path()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized + AsRef<OsStr>> From<&T> for PathBuf {
/// Converts a borrowed [`OsStr`] to a [`PathBuf`].
///
/// Allocates a [`PathBuf`] and copies the data into it.
#[inline]
fn from(s: &T) -> PathBuf {
PathBuf::from(s.as_ref().to_os_string())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl From<OsString> for PathBuf {
/// Converts an [`OsString`] into a [`PathBuf`].
///
/// This conversion does not allocate or copy memory.
#[inline]
fn from(s: OsString) -> PathBuf {
PathBuf { inner: s }
}
}
#[stable(feature = "from_path_buf_for_os_string", since = "1.14.0")]
impl From<PathBuf> for OsString {
/// Converts a [`PathBuf`] into an [`OsString`]
///
/// This conversion does not allocate or copy memory.
#[inline]
fn from(path_buf: PathBuf) -> OsString {
path_buf.inner
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl From<String> for PathBuf {
/// Converts a [`String`] into a [`PathBuf`]
///
/// This conversion does not allocate or copy memory.
#[inline]
fn from(s: String) -> PathBuf {
PathBuf::from(OsString::from(s))
}
}
#[stable(feature = "path_from_str", since = "1.32.0")]
impl FromStr for PathBuf {
type Err = core::convert::Infallible;
#[inline]
fn from_str(s: &str) -> Result<Self, Self::Err> {
Ok(PathBuf::from(s))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<P: AsRef<Path>> FromIterator<P> for PathBuf {
fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> PathBuf {
let mut buf = PathBuf::new();
buf.extend(iter);
buf
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<P: AsRef<Path>> Extend<P> for PathBuf {
fn extend<I: IntoIterator<Item = P>>(&mut self, iter: I) {
iter.into_iter().for_each(move |p| self.push(p.as_ref()));
}
#[inline]
fn extend_one(&mut self, p: P) {
self.push(p.as_ref());
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for PathBuf {
fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&**self, formatter)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl ops::Deref for PathBuf {
type Target = Path;
#[inline]
fn deref(&self) -> &Path {
Path::new(&self.inner)
}
}
#[stable(feature = "path_buf_deref_mut", since = "1.68.0")]
impl ops::DerefMut for PathBuf {
#[inline]
fn deref_mut(&mut self) -> &mut Path {
Path::from_inner_mut(&mut self.inner)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Borrow<Path> for PathBuf {
#[inline]
fn borrow(&self) -> &Path {
self.deref()
}
}
#[stable(feature = "default_for_pathbuf", since = "1.17.0")]
impl Default for PathBuf {
#[inline]
fn default() -> Self {
PathBuf::new()
}
}
#[stable(feature = "cow_from_path", since = "1.6.0")]
impl<'a> From<&'a Path> for Cow<'a, Path> {
/// Creates a clone-on-write pointer from a reference to
/// [`Path`].
///
/// This conversion does not clone or allocate.
#[inline]
fn from(s: &'a Path) -> Cow<'a, Path> {
Cow::Borrowed(s)
}
}
#[stable(feature = "cow_from_path", since = "1.6.0")]
impl<'a> From<PathBuf> for Cow<'a, Path> {
/// Creates a clone-on-write pointer from an owned
/// instance of [`PathBuf`].
///
/// This conversion does not clone or allocate.
#[inline]
fn from(s: PathBuf) -> Cow<'a, Path> {
Cow::Owned(s)
}
}
#[stable(feature = "cow_from_pathbuf_ref", since = "1.28.0")]
impl<'a> From<&'a PathBuf> for Cow<'a, Path> {
/// Creates a clone-on-write pointer from a reference to
/// [`PathBuf`].
///
/// This conversion does not clone or allocate.
#[inline]
fn from(p: &'a PathBuf) -> Cow<'a, Path> {
Cow::Borrowed(p.as_path())
}
}
#[stable(feature = "pathbuf_from_cow_path", since = "1.28.0")]
impl<'a> From<Cow<'a, Path>> for PathBuf {
/// Converts a clone-on-write pointer to an owned path.
///
/// Converting from a `Cow::Owned` does not clone or allocate.
#[inline]
fn from(p: Cow<'a, Path>) -> Self {
p.into_owned()
}
}
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<PathBuf> for Arc<Path> {
/// Converts a [`PathBuf`] into an <code>[Arc]<[Path]></code> by moving the [`PathBuf`] data
/// into a new [`Arc`] buffer.
#[inline]
fn from(s: PathBuf) -> Arc<Path> {
let arc: Arc<OsStr> = Arc::from(s.into_os_string());
unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) }
}
}
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<&Path> for Arc<Path> {
/// Converts a [`Path`] into an [`Arc`] by copying the [`Path`] data into a new [`Arc`] buffer.
#[inline]
fn from(s: &Path) -> Arc<Path> {
let arc: Arc<OsStr> = Arc::from(s.as_os_str());
unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) }
}
}
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<PathBuf> for Rc<Path> {
/// Converts a [`PathBuf`] into an <code>[Rc]<[Path]></code> by moving the [`PathBuf`] data into
/// a new [`Rc`] buffer.
#[inline]
fn from(s: PathBuf) -> Rc<Path> {
let rc: Rc<OsStr> = Rc::from(s.into_os_string());
unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) }
}
}
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<&Path> for Rc<Path> {
/// Converts a [`Path`] into an [`Rc`] by copying the [`Path`] data into a new [`Rc`] buffer.
#[inline]
fn from(s: &Path) -> Rc<Path> {
let rc: Rc<OsStr> = Rc::from(s.as_os_str());
unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl ToOwned for Path {
type Owned = PathBuf;
#[inline]
fn to_owned(&self) -> PathBuf {
self.to_path_buf()
}
#[inline]
fn clone_into(&self, target: &mut PathBuf) {
self.inner.clone_into(&mut target.inner);
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialEq for PathBuf {
#[inline]
fn eq(&self, other: &PathBuf) -> bool {
self.components() == other.components()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Hash for PathBuf {
fn hash<H: Hasher>(&self, h: &mut H) {
self.as_path().hash(h)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Eq for PathBuf {}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialOrd for PathBuf {
#[inline]
fn partial_cmp(&self, other: &PathBuf) -> Option<cmp::Ordering> {
Some(compare_components(self.components(), other.components()))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Ord for PathBuf {
#[inline]
fn cmp(&self, other: &PathBuf) -> cmp::Ordering {
compare_components(self.components(), other.components())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<OsStr> for PathBuf {
#[inline]
fn as_ref(&self) -> &OsStr {
&self.inner[..]
}
}
/// A slice of a path (akin to [`str`]).
///
/// This type supports a number of operations for inspecting a path, including
/// breaking the path into its components (separated by `/` on Unix and by either
/// `/` or `\` on Windows), extracting the file name, determining whether the path
/// is absolute, and so on.
///
/// This is an *unsized* type, meaning that it must always be used behind a
/// pointer like `&` or [`Box`]. For an owned version of this type,
/// see [`PathBuf`].
///
/// More details about the overall approach can be found in
/// the [module documentation](self).
///
/// # Examples
///
/// ```
/// use std::path::Path;
/// use std::ffi::OsStr;
///
/// // Note: this example does work on Windows
/// let path = Path::new("./foo/bar.txt");
///
/// let parent = path.parent();
/// assert_eq!(parent, Some(Path::new("./foo")));
///
/// let file_stem = path.file_stem();
/// assert_eq!(file_stem, Some(OsStr::new("bar")));
///
/// let extension = path.extension();
/// assert_eq!(extension, Some(OsStr::new("txt")));
/// ```
#[cfg_attr(not(test), rustc_diagnostic_item = "Path")]
#[stable(feature = "rust1", since = "1.0.0")]
// `Path::new` current implementation relies
// on `Path` being layout-compatible with `OsStr`.
// However, `Path` layout is considered an implementation detail and must not be relied upon.
#[repr(transparent)]
pub struct Path {
inner: OsStr,
}
/// An error returned from [`Path::strip_prefix`] if the prefix was not found.
///
/// This `struct` is created by the [`strip_prefix`] method on [`Path`].
/// See its documentation for more.
///
/// [`strip_prefix`]: Path::strip_prefix
#[derive(Debug, Clone, PartialEq, Eq)]
#[stable(since = "1.7.0", feature = "strip_prefix")]
pub struct StripPrefixError(());
impl Path {
// The following (private!) function allows construction of a path from a u8
// slice, which is only safe when it is known to follow the OsStr encoding.
unsafe fn from_u8_slice(s: &[u8]) -> &Path {
unsafe { Path::new(OsStr::from_encoded_bytes_unchecked(s)) }
}
// The following (private!) function reveals the byte encoding used for OsStr.
fn as_u8_slice(&self) -> &[u8] {
self.inner.as_encoded_bytes()
}
/// Directly wraps a string slice as a `Path` slice.
///
/// This is a cost-free conversion.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// Path::new("foo.txt");
/// ```
///
/// You can create `Path`s from `String`s, or even other `Path`s:
///
/// ```
/// use std::path::Path;
///
/// let string = String::from("foo.txt");
/// let from_string = Path::new(&string);
/// let from_path = Path::new(&from_string);
/// assert_eq!(from_string, from_path);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &Path {
unsafe { &*(s.as_ref() as *const OsStr as *const Path) }
}
fn from_inner_mut(inner: &mut OsStr) -> &mut Path {
// SAFETY: Path is just a wrapper around OsStr,
// therefore converting &mut OsStr to &mut Path is safe.
unsafe { &mut *(inner as *mut OsStr as *mut Path) }
}
/// Yields the underlying [`OsStr`] slice.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let os_str = Path::new("foo.txt").as_os_str();
/// assert_eq!(os_str, std::ffi::OsStr::new("foo.txt"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn as_os_str(&self) -> &OsStr {
&self.inner
}
/// Yields a mutable reference to the underlying [`OsStr`] slice.
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let mut path = PathBuf::from("Foo.TXT");
///
/// assert_ne!(path, Path::new("foo.txt"));
///
/// path.as_mut_os_str().make_ascii_lowercase();
/// assert_eq!(path, Path::new("foo.txt"));
/// ```
#[stable(feature = "path_as_mut_os_str", since = "1.70.0")]
#[must_use]
#[inline]
pub fn as_mut_os_str(&mut self) -> &mut OsStr {
&mut self.inner
}
/// Yields a [`&str`] slice if the `Path` is valid unicode.
///
/// This conversion may entail doing a check for UTF-8 validity.
/// Note that validation is performed because non-UTF-8 strings are
/// perfectly valid for some OS.
///
/// [`&str`]: str
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("foo.txt");
/// assert_eq!(path.to_str(), Some("foo.txt"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub fn to_str(&self) -> Option<&str> {
self.inner.to_str()
}
/// Converts a `Path` to a [`Cow<str>`].
///
/// Any non-UTF-8 sequences are replaced with
/// [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD].
///
/// [U+FFFD]: super::char::REPLACEMENT_CHARACTER
///
/// # Examples
///
/// Calling `to_string_lossy` on a `Path` with valid unicode:
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("foo.txt");
/// assert_eq!(path.to_string_lossy(), "foo.txt");
/// ```
///
/// Had `path` contained invalid unicode, the `to_string_lossy` call might
/// have returned `"fo�.txt"`.
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub fn to_string_lossy(&self) -> Cow<'_, str> {
self.inner.to_string_lossy()
}
/// Converts a `Path` to an owned [`PathBuf`].
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let path_buf = Path::new("foo.txt").to_path_buf();
/// assert_eq!(path_buf, PathBuf::from("foo.txt"));
/// ```
#[rustc_conversion_suggestion]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[stable(feature = "rust1", since = "1.0.0")]
#[cfg_attr(not(test), rustc_diagnostic_item = "path_to_pathbuf")]
pub fn to_path_buf(&self) -> PathBuf {
PathBuf::from(self.inner.to_os_string())
}
/// Returns `true` if the `Path` is absolute, i.e., if it is independent of
/// the current directory.
///
/// * On Unix, a path is absolute if it starts with the root, so
/// `is_absolute` and [`has_root`] are equivalent.
///
/// * On Windows, a path is absolute if it has a prefix and starts with the
/// root: `c:\windows` is absolute, while `c:temp` and `\temp` are not.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// assert!(!Path::new("foo.txt").is_absolute());
/// ```
///
/// [`has_root`]: Path::has_root
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[allow(deprecated)]
pub fn is_absolute(&self) -> bool {
if cfg!(target_os = "redox") {
// FIXME: Allow Redox prefixes
self.has_root() || has_redox_scheme(self.as_u8_slice())
} else {
self.has_root() && (cfg!(any(unix, target_os = "wasi")) || self.prefix().is_some())
}
}
/// Returns `true` if the `Path` is relative, i.e., not absolute.
///
/// See [`is_absolute`]'s documentation for more details.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// assert!(Path::new("foo.txt").is_relative());
/// ```
///
/// [`is_absolute`]: Path::is_absolute
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn is_relative(&self) -> bool {
!self.is_absolute()
}
fn prefix(&self) -> Option<Prefix<'_>> {
self.components().prefix
}
/// Returns `true` if the `Path` has a root.
///
/// * On Unix, a path has a root if it begins with `/`.
///
/// * On Windows, a path has a root if it:
/// * has no prefix and begins with a separator, e.g., `\windows`
/// * has a prefix followed by a separator, e.g., `c:\windows` but not `c:windows`
/// * has any non-disk prefix, e.g., `\\server\share`
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// assert!(Path::new("/etc/passwd").has_root());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn has_root(&self) -> bool {
self.components().has_root()
}
/// Returns the `Path` without its final component, if there is one.
///
/// This means it returns `Some("")` for relative paths with one component.
///
/// Returns [`None`] if the path terminates in a root or prefix, or if it's
/// the empty string.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/foo/bar");
/// let parent = path.parent().unwrap();
/// assert_eq!(parent, Path::new("/foo"));
///
/// let grand_parent = parent.parent().unwrap();
/// assert_eq!(grand_parent, Path::new("/"));
/// assert_eq!(grand_parent.parent(), None);
///
/// let relative_path = Path::new("foo/bar");
/// let parent = relative_path.parent();
/// assert_eq!(parent, Some(Path::new("foo")));
/// let grand_parent = parent.and_then(Path::parent);
/// assert_eq!(grand_parent, Some(Path::new("")));
/// let great_grand_parent = grand_parent.and_then(Path::parent);
/// assert_eq!(great_grand_parent, None);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(alias = "dirname")]
#[must_use]
pub fn parent(&self) -> Option<&Path> {
let mut comps = self.components();
let comp = comps.next_back();
comp.and_then(|p| match p {
Component::Normal(_) | Component::CurDir | Component::ParentDir => {
Some(comps.as_path())
}
_ => None,
})
}
/// Produces an iterator over `Path` and its ancestors.
///
/// The iterator will yield the `Path` that is returned if the [`parent`] method is used zero
/// or more times. If the [`parent`] method returns [`None`], the iterator will do likewise.
/// The iterator will always yield at least one value, namely `Some(&self)`. Next it will yield
/// `&self.parent()`, `&self.parent().and_then(Path::parent)` and so on.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let mut ancestors = Path::new("/foo/bar").ancestors();
/// assert_eq!(ancestors.next(), Some(Path::new("/foo/bar")));
/// assert_eq!(ancestors.next(), Some(Path::new("/foo")));
/// assert_eq!(ancestors.next(), Some(Path::new("/")));
/// assert_eq!(ancestors.next(), None);
///
/// let mut ancestors = Path::new("../foo/bar").ancestors();
/// assert_eq!(ancestors.next(), Some(Path::new("../foo/bar")));
/// assert_eq!(ancestors.next(), Some(Path::new("../foo")));
/// assert_eq!(ancestors.next(), Some(Path::new("..")));
/// assert_eq!(ancestors.next(), Some(Path::new("")));
/// assert_eq!(ancestors.next(), None);
/// ```
///
/// [`parent`]: Path::parent
#[stable(feature = "path_ancestors", since = "1.28.0")]
#[inline]
pub fn ancestors(&self) -> Ancestors<'_> {
Ancestors { next: Some(&self) }
}
/// Returns the final component of the `Path`, if there is one.
///
/// If the path is a normal file, this is the file name. If it's the path of a directory, this
/// is the directory name.
///
/// Returns [`None`] if the path terminates in `..`.
///
/// # Examples
///
/// ```
/// use std::path::Path;
/// use std::ffi::OsStr;
///
/// assert_eq!(Some(OsStr::new("bin")), Path::new("/usr/bin/").file_name());
/// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("tmp/foo.txt").file_name());
/// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name());
/// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name());
/// assert_eq!(None, Path::new("foo.txt/..").file_name());
/// assert_eq!(None, Path::new("/").file_name());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(alias = "basename")]
#[must_use]
pub fn file_name(&self) -> Option<&OsStr> {
self.components().next_back().and_then(|p| match p {
Component::Normal(p) => Some(p),
_ => None,
})
}
/// Returns a path that, when joined onto `base`, yields `self`.
///
/// # Errors
///
/// If `base` is not a prefix of `self` (i.e., [`starts_with`]
/// returns `false`), returns [`Err`].
///
/// [`starts_with`]: Path::starts_with
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let path = Path::new("/test/haha/foo.txt");
///
/// assert_eq!(path.strip_prefix("/"), Ok(Path::new("test/haha/foo.txt")));
/// assert_eq!(path.strip_prefix("/test"), Ok(Path::new("haha/foo.txt")));
/// assert_eq!(path.strip_prefix("/test/"), Ok(Path::new("haha/foo.txt")));
/// assert_eq!(path.strip_prefix("/test/haha/foo.txt"), Ok(Path::new("")));
/// assert_eq!(path.strip_prefix("/test/haha/foo.txt/"), Ok(Path::new("")));
///
/// assert!(path.strip_prefix("test").is_err());
/// assert!(path.strip_prefix("/haha").is_err());
///
/// let prefix = PathBuf::from("/test/");
/// assert_eq!(path.strip_prefix(prefix), Ok(Path::new("haha/foo.txt")));
/// ```
#[stable(since = "1.7.0", feature = "path_strip_prefix")]
pub fn strip_prefix<P>(&self, base: P) -> Result<&Path, StripPrefixError>
where
P: AsRef<Path>,
{
self._strip_prefix(base.as_ref())
}
fn _strip_prefix(&self, base: &Path) -> Result<&Path, StripPrefixError> {
iter_after(self.components(), base.components())
.map(|c| c.as_path())
.ok_or(StripPrefixError(()))
}
/// Determines whether `base` is a prefix of `self`.
///
/// Only considers whole path components to match.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/etc/passwd");
///
/// assert!(path.starts_with("/etc"));
/// assert!(path.starts_with("/etc/"));
/// assert!(path.starts_with("/etc/passwd"));
/// assert!(path.starts_with("/etc/passwd/")); // extra slash is okay
/// assert!(path.starts_with("/etc/passwd///")); // multiple extra slashes are okay
///
/// assert!(!path.starts_with("/e"));
/// assert!(!path.starts_with("/etc/passwd.txt"));
///
/// assert!(!Path::new("/etc/foo.rs").starts_with("/etc/foo"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
pub fn starts_with<P: AsRef<Path>>(&self, base: P) -> bool {
self._starts_with(base.as_ref())
}
fn _starts_with(&self, base: &Path) -> bool {
iter_after(self.components(), base.components()).is_some()
}
/// Determines whether `child` is a suffix of `self`.
///
/// Only considers whole path components to match.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/etc/resolv.conf");
///
/// assert!(path.ends_with("resolv.conf"));
/// assert!(path.ends_with("etc/resolv.conf"));
/// assert!(path.ends_with("/etc/resolv.conf"));
///
/// assert!(!path.ends_with("/resolv.conf"));
/// assert!(!path.ends_with("conf")); // use .extension() instead
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
pub fn ends_with<P: AsRef<Path>>(&self, child: P) -> bool {
self._ends_with(child.as_ref())
}
fn _ends_with(&self, child: &Path) -> bool {
iter_after(self.components().rev(), child.components().rev()).is_some()
}
/// Extracts the stem (non-extension) portion of [`self.file_name`].
///
/// [`self.file_name`]: Path::file_name
///
/// The stem is:
///
/// * [`None`], if there is no file name;
/// * The entire file name if there is no embedded `.`;
/// * The entire file name if the file name begins with `.` and has no other `.`s within;
/// * Otherwise, the portion of the file name before the final `.`
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// assert_eq!("foo", Path::new("foo.rs").file_stem().unwrap());
/// assert_eq!("foo.tar", Path::new("foo.tar.gz").file_stem().unwrap());
/// ```
///
/// # See Also
/// This method is similar to [`Path::file_prefix`], which extracts the portion of the file name
/// before the *first* `.`
///
/// [`Path::file_prefix`]: Path::file_prefix
///
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
pub fn file_stem(&self) -> Option<&OsStr> {
self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.or(after))
}
/// Extracts the prefix of [`self.file_name`].
///
/// The prefix is:
///
/// * [`None`], if there is no file name;
/// * The entire file name if there is no embedded `.`;
/// * The portion of the file name before the first non-beginning `.`;
/// * The entire file name if the file name begins with `.` and has no other `.`s within;
/// * The portion of the file name before the second `.` if the file name begins with `.`
///
/// [`self.file_name`]: Path::file_name
///
/// # Examples
///
/// ```
/// # #![feature(path_file_prefix)]
/// use std::path::Path;
///
/// assert_eq!("foo", Path::new("foo.rs").file_prefix().unwrap());
/// assert_eq!("foo", Path::new("foo.tar.gz").file_prefix().unwrap());
/// ```
///
/// # See Also
/// This method is similar to [`Path::file_stem`], which extracts the portion of the file name
/// before the *last* `.`
///
/// [`Path::file_stem`]: Path::file_stem
///
#[unstable(feature = "path_file_prefix", issue = "86319")]
#[must_use]
pub fn file_prefix(&self) -> Option<&OsStr> {
self.file_name().map(split_file_at_dot).and_then(|(before, _after)| Some(before))
}
/// Extracts the extension (without the leading dot) of [`self.file_name`], if possible.
///
/// The extension is:
///
/// * [`None`], if there is no file name;
/// * [`None`], if there is no embedded `.`;
/// * [`None`], if the file name begins with `.` and has no other `.`s within;
/// * Otherwise, the portion of the file name after the final `.`
///
/// [`self.file_name`]: Path::file_name
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// assert_eq!("rs", Path::new("foo.rs").extension().unwrap());
/// assert_eq!("gz", Path::new("foo.tar.gz").extension().unwrap());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
pub fn extension(&self) -> Option<&OsStr> {
self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.and(after))
}
/// Creates an owned [`PathBuf`] with `path` adjoined to `self`.
///
/// If `path` is absolute, it replaces the current path.
///
/// See [`PathBuf::push`] for more details on what it means to adjoin a path.
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// assert_eq!(Path::new("/etc").join("passwd"), PathBuf::from("/etc/passwd"));
/// assert_eq!(Path::new("/etc").join("/bin/sh"), PathBuf::from("/bin/sh"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
pub fn join<P: AsRef<Path>>(&self, path: P) -> PathBuf {
self._join(path.as_ref())
}
fn _join(&self, path: &Path) -> PathBuf {
let mut buf = self.to_path_buf();
buf.push(path);
buf
}
/// Creates an owned [`PathBuf`] like `self` but with the given file name.
///
/// See [`PathBuf::set_file_name`] for more details.
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let path = Path::new("/tmp/foo.png");
/// assert_eq!(path.with_file_name("bar"), PathBuf::from("/tmp/bar"));
/// assert_eq!(path.with_file_name("bar.txt"), PathBuf::from("/tmp/bar.txt"));
///
/// let path = Path::new("/tmp");
/// assert_eq!(path.with_file_name("var"), PathBuf::from("/var"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
pub fn with_file_name<S: AsRef<OsStr>>(&self, file_name: S) -> PathBuf {
self._with_file_name(file_name.as_ref())
}
fn _with_file_name(&self, file_name: &OsStr) -> PathBuf {
let mut buf = self.to_path_buf();
buf.set_file_name(file_name);
buf
}
/// Creates an owned [`PathBuf`] like `self` but with the given extension.
///
/// See [`PathBuf::set_extension`] for more details.
///
/// # Examples
///
/// ```
/// use std::path::{Path, PathBuf};
///
/// let path = Path::new("foo.rs");
/// assert_eq!(path.with_extension("txt"), PathBuf::from("foo.txt"));
///
/// let path = Path::new("foo.tar.gz");
/// assert_eq!(path.with_extension(""), PathBuf::from("foo.tar"));
/// assert_eq!(path.with_extension("xz"), PathBuf::from("foo.tar.xz"));
/// assert_eq!(path.with_extension("").with_extension("txt"), PathBuf::from("foo.txt"));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn with_extension<S: AsRef<OsStr>>(&self, extension: S) -> PathBuf {
self._with_extension(extension.as_ref())
}
fn _with_extension(&self, extension: &OsStr) -> PathBuf {
let self_len = self.as_os_str().len();
let self_bytes = self.as_os_str().as_encoded_bytes();
let (new_capacity, slice_to_copy) = match self.extension() {
None => {
// Enough capacity for the extension and the dot
let capacity = self_len + extension.len() + 1;
let whole_path = self_bytes;
(capacity, whole_path)
}
Some(previous_extension) => {
let capacity = self_len + extension.len() - previous_extension.len();
let path_till_dot = &self_bytes[..self_len - previous_extension.len()];
(capacity, path_till_dot)
}
};
let mut new_path = PathBuf::with_capacity(new_capacity);
new_path.inner.extend_from_slice(slice_to_copy);
new_path.set_extension(extension);
new_path
}
/// Creates an owned [`PathBuf`] like `self` but with the extension added.
///
/// See [`PathBuf::add_extension`] for more details.
///
/// # Examples
///
/// ```
/// #![feature(path_add_extension)]
///
/// use std::path::{Path, PathBuf};
///
/// let path = Path::new("foo.rs");
/// assert_eq!(path.with_added_extension("txt"), PathBuf::from("foo.rs.txt"));
///
/// let path = Path::new("foo.tar.gz");
/// assert_eq!(path.with_added_extension(""), PathBuf::from("foo.tar.gz"));
/// assert_eq!(path.with_added_extension("xz"), PathBuf::from("foo.tar.gz.xz"));
/// assert_eq!(path.with_added_extension("").with_added_extension("txt"), PathBuf::from("foo.tar.gz.txt"));
/// ```
#[unstable(feature = "path_add_extension", issue = "127292")]
pub fn with_added_extension<S: AsRef<OsStr>>(&self, extension: S) -> PathBuf {
let mut new_path = self.to_path_buf();
new_path.add_extension(extension);
new_path
}
/// Produces an iterator over the [`Component`]s of the path.
///
/// When parsing the path, there is a small amount of normalization:
///
/// * Repeated separators are ignored, so `a/b` and `a//b` both have
/// `a` and `b` as components.
///
/// * Occurrences of `.` are normalized away, except if they are at the
/// beginning of the path. For example, `a/./b`, `a/b/`, `a/b/.` and
/// `a/b` all have `a` and `b` as components, but `./a/b` starts with
/// an additional [`CurDir`] component.
///
/// * A trailing slash is normalized away, `/a/b` and `/a/b/` are equivalent.
///
/// Note that no other normalization takes place; in particular, `a/c`
/// and `a/b/../c` are distinct, to account for the possibility that `b`
/// is a symbolic link (so its parent isn't `a`).
///
/// # Examples
///
/// ```
/// use std::path::{Path, Component};
/// use std::ffi::OsStr;
///
/// let mut components = Path::new("/tmp/foo.txt").components();
///
/// assert_eq!(components.next(), Some(Component::RootDir));
/// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("tmp"))));
/// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("foo.txt"))));
/// assert_eq!(components.next(), None)
/// ```
///
/// [`CurDir`]: Component::CurDir
#[stable(feature = "rust1", since = "1.0.0")]
pub fn components(&self) -> Components<'_> {
let prefix = parse_prefix(self.as_os_str());
Components {
path: self.as_u8_slice(),
prefix,
has_physical_root: has_physical_root(self.as_u8_slice(), prefix)
|| has_redox_scheme(self.as_u8_slice()),
front: State::Prefix,
back: State::Body,
}
}
/// Produces an iterator over the path's components viewed as [`OsStr`]
/// slices.
///
/// For more information about the particulars of how the path is separated
/// into components, see [`components`].
///
/// [`components`]: Path::components
///
/// # Examples
///
/// ```
/// use std::path::{self, Path};
/// use std::ffi::OsStr;
///
/// let mut it = Path::new("/tmp/foo.txt").iter();
/// assert_eq!(it.next(), Some(OsStr::new(&path::MAIN_SEPARATOR.to_string())));
/// assert_eq!(it.next(), Some(OsStr::new("tmp")));
/// assert_eq!(it.next(), Some(OsStr::new("foo.txt")));
/// assert_eq!(it.next(), None)
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn iter(&self) -> Iter<'_> {
Iter { inner: self.components() }
}
/// Returns an object that implements [`Display`] for safely printing paths
/// that may contain non-Unicode data. This may perform lossy conversion,
/// depending on the platform. If you would like an implementation which
/// escapes the path please use [`Debug`] instead.
///
/// [`Display`]: fmt::Display
/// [`Debug`]: fmt::Debug
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/tmp/foo.rs");
///
/// println!("{}", path.display());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use = "this does not display the path, \
it returns an object that can be displayed"]
#[inline]
pub fn display(&self) -> Display<'_> {
Display { inner: self.inner.display() }
}
/// Queries the file system to get information about a file, directory, etc.
///
/// This function will traverse symbolic links to query information about the
/// destination file.
///
/// This is an alias to [`fs::metadata`].
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
///
/// let path = Path::new("/Minas/tirith");
/// let metadata = path.metadata().expect("metadata call failed");
/// println!("{:?}", metadata.file_type());
/// ```
#[stable(feature = "path_ext", since = "1.5.0")]
#[inline]
pub fn metadata(&self) -> io::Result<fs::Metadata> {
fs::metadata(self)
}
/// Queries the metadata about a file without following symlinks.
///
/// This is an alias to [`fs::symlink_metadata`].
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
///
/// let path = Path::new("/Minas/tirith");
/// let metadata = path.symlink_metadata().expect("symlink_metadata call failed");
/// println!("{:?}", metadata.file_type());
/// ```
#[stable(feature = "path_ext", since = "1.5.0")]
#[inline]
pub fn symlink_metadata(&self) -> io::Result<fs::Metadata> {
fs::symlink_metadata(self)
}
/// Returns the canonical, absolute form of the path with all intermediate
/// components normalized and symbolic links resolved.
///
/// This is an alias to [`fs::canonicalize`].
///
/// # Examples
///
/// ```no_run
/// use std::path::{Path, PathBuf};
///
/// let path = Path::new("/foo/test/../test/bar.rs");
/// assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs"));
/// ```
#[stable(feature = "path_ext", since = "1.5.0")]
#[inline]
pub fn canonicalize(&self) -> io::Result<PathBuf> {
fs::canonicalize(self)
}
/// Reads a symbolic link, returning the file that the link points to.
///
/// This is an alias to [`fs::read_link`].
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
///
/// let path = Path::new("/laputa/sky_castle.rs");
/// let path_link = path.read_link().expect("read_link call failed");
/// ```
#[stable(feature = "path_ext", since = "1.5.0")]
#[inline]
pub fn read_link(&self) -> io::Result<PathBuf> {
fs::read_link(self)
}
/// Returns an iterator over the entries within a directory.
///
/// The iterator will yield instances of <code>[io::Result]<[fs::DirEntry]></code>. New
/// errors may be encountered after an iterator is initially constructed.
///
/// This is an alias to [`fs::read_dir`].
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
///
/// let path = Path::new("/laputa");
/// for entry in path.read_dir().expect("read_dir call failed") {
/// if let Ok(entry) = entry {
/// println!("{:?}", entry.path());
/// }
/// }
/// ```
#[stable(feature = "path_ext", since = "1.5.0")]
#[inline]
pub fn read_dir(&self) -> io::Result<fs::ReadDir> {
fs::read_dir(self)
}
/// Returns `true` if the path points at an existing entity.
///
/// Warning: this method may be error-prone, consider using [`try_exists()`] instead!
/// It also has a risk of introducing time-of-check to time-of-use (TOCTOU) bugs.
///
/// This function will traverse symbolic links to query information about the
/// destination file.
///
/// If you cannot access the metadata of the file, e.g. because of a
/// permission error or broken symbolic links, this will return `false`.
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
/// assert!(!Path::new("does_not_exist.txt").exists());
/// ```
///
/// # See Also
///
/// This is a convenience function that coerces errors to false. If you want to
/// check errors, call [`Path::try_exists`].
///
/// [`try_exists()`]: Self::try_exists
#[stable(feature = "path_ext", since = "1.5.0")]
#[must_use]
#[inline]
pub fn exists(&self) -> bool {
fs::metadata(self).is_ok()
}
/// Returns `Ok(true)` if the path points at an existing entity.
///
/// This function will traverse symbolic links to query information about the
/// destination file. In case of broken symbolic links this will return `Ok(false)`.
///
/// [`Path::exists()`] only checks whether or not a path was both found and readable. By
/// contrast, `try_exists` will return `Ok(true)` or `Ok(false)`, respectively, if the path
/// was _verified_ to exist or not exist. If its existence can neither be confirmed nor
/// denied, it will propagate an `Err(_)` instead. This can be the case if e.g. listing
/// permission is denied on one of the parent directories.
///
/// Note that while this avoids some pitfalls of the `exists()` method, it still can not
/// prevent time-of-check to time-of-use (TOCTOU) bugs. You should only use it in scenarios
/// where those bugs are not an issue.
///
/// This is an alias for [`std::fs::exists`](crate::fs::exists).
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
/// assert!(!Path::new("does_not_exist.txt").try_exists().expect("Can't check existence of file does_not_exist.txt"));
/// assert!(Path::new("/root/secret_file.txt").try_exists().is_err());
/// ```
///
/// [`exists()`]: Self::exists
#[stable(feature = "path_try_exists", since = "1.63.0")]
#[inline]
pub fn try_exists(&self) -> io::Result<bool> {
fs::exists(self)
}
/// Returns `true` if the path exists on disk and is pointing at a regular file.
///
/// This function will traverse symbolic links to query information about the
/// destination file.
///
/// If you cannot access the metadata of the file, e.g. because of a
/// permission error or broken symbolic links, this will return `false`.
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
/// assert_eq!(Path::new("./is_a_directory/").is_file(), false);
/// assert_eq!(Path::new("a_file.txt").is_file(), true);
/// ```
///
/// # See Also
///
/// This is a convenience function that coerces errors to false. If you want to
/// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call
/// [`fs::Metadata::is_file`] if it was [`Ok`].
///
/// When the goal is simply to read from (or write to) the source, the most
/// reliable way to test the source can be read (or written to) is to open
/// it. Only using `is_file` can break workflows like `diff <( prog_a )` on
/// a Unix-like system for example. See [`fs::File::open`] or
/// [`fs::OpenOptions::open`] for more information.
#[stable(feature = "path_ext", since = "1.5.0")]
#[must_use]
pub fn is_file(&self) -> bool {
fs::metadata(self).map(|m| m.is_file()).unwrap_or(false)
}
/// Returns `true` if the path exists on disk and is pointing at a directory.
///
/// This function will traverse symbolic links to query information about the
/// destination file.
///
/// If you cannot access the metadata of the file, e.g. because of a
/// permission error or broken symbolic links, this will return `false`.
///
/// # Examples
///
/// ```no_run
/// use std::path::Path;
/// assert_eq!(Path::new("./is_a_directory/").is_dir(), true);
/// assert_eq!(Path::new("a_file.txt").is_dir(), false);
/// ```
///
/// # See Also
///
/// This is a convenience function that coerces errors to false. If you want to
/// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call
/// [`fs::Metadata::is_dir`] if it was [`Ok`].
#[stable(feature = "path_ext", since = "1.5.0")]
#[must_use]
pub fn is_dir(&self) -> bool {
fs::metadata(self).map(|m| m.is_dir()).unwrap_or(false)
}
/// Returns `true` if the path exists on disk and is pointing at a symbolic link.
///
/// This function will not traverse symbolic links.
/// In case of a broken symbolic link this will also return true.
///
/// If you cannot access the directory containing the file, e.g., because of a
/// permission error, this will return false.
///
/// # Examples
///
#[cfg_attr(unix, doc = "```no_run")]
#[cfg_attr(not(unix), doc = "```ignore")]
/// use std::path::Path;
/// use std::os::unix::fs::symlink;
///
/// let link_path = Path::new("link");
/// symlink("/origin_does_not_exist/", link_path).unwrap();
/// assert_eq!(link_path.is_symlink(), true);
/// assert_eq!(link_path.exists(), false);
/// ```
///
/// # See Also
///
/// This is a convenience function that coerces errors to false. If you want to
/// check errors, call [`fs::symlink_metadata`] and handle its [`Result`]. Then call
/// [`fs::Metadata::is_symlink`] if it was [`Ok`].
#[must_use]
#[stable(feature = "is_symlink", since = "1.58.0")]
pub fn is_symlink(&self) -> bool {
fs::symlink_metadata(self).map(|m| m.is_symlink()).unwrap_or(false)
}
/// Converts a [`Box<Path>`](Box) into a [`PathBuf`] without copying or
/// allocating.
#[stable(feature = "into_boxed_path", since = "1.20.0")]
#[must_use = "`self` will be dropped if the result is not used"]
pub fn into_path_buf(self: Box<Path>) -> PathBuf {
let rw = Box::into_raw(self) as *mut OsStr;
let inner = unsafe { Box::from_raw(rw) };
PathBuf { inner: OsString::from(inner) }
}
}
#[unstable(feature = "clone_to_uninit", issue = "126799")]
unsafe impl CloneToUninit for Path {
#[inline]
#[cfg_attr(debug_assertions, track_caller)]
unsafe fn clone_to_uninit(&self, dst: *mut Self) {
// SAFETY: Path is just a wrapper around OsStr
unsafe { self.inner.clone_to_uninit(&raw mut (*dst).inner) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<OsStr> for Path {
#[inline]
fn as_ref(&self) -> &OsStr {
&self.inner
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for Path {
fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&self.inner, formatter)
}
}
/// Helper struct for safely printing paths with [`format!`] and `{}`.
///
/// A [`Path`] might contain non-Unicode data. This `struct` implements the
/// [`Display`] trait in a way that mitigates that. It is created by the
/// [`display`](Path::display) method on [`Path`]. This may perform lossy
/// conversion, depending on the platform. If you would like an implementation
/// which escapes the path please use [`Debug`] instead.
///
/// # Examples
///
/// ```
/// use std::path::Path;
///
/// let path = Path::new("/tmp/foo.rs");
///
/// println!("{}", path.display());
/// ```
///
/// [`Display`]: fmt::Display
/// [`format!`]: crate::format
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Display<'a> {
inner: os_str::Display<'a>,
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for Display<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&self.inner, f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for Display<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.inner, f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialEq for Path {
#[inline]
fn eq(&self, other: &Path) -> bool {
self.components() == other.components()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Hash for Path {
fn hash<H: Hasher>(&self, h: &mut H) {
let bytes = self.as_u8_slice();
let (prefix_len, verbatim) = match parse_prefix(&self.inner) {
Some(prefix) => {
prefix.hash(h);
(prefix.len(), prefix.is_verbatim())
}
None => (0, false),
};
let bytes = &bytes[prefix_len..];
let mut component_start = 0;
// track some extra state to avoid prefix collisions.
// ["foo", "bar"] and ["foobar"], will have the same payload bytes
// but result in different chunk_bits
let mut chunk_bits: usize = 0;
for i in 0..bytes.len() {
let is_sep = if verbatim { is_verbatim_sep(bytes[i]) } else { is_sep_byte(bytes[i]) };
if is_sep {
if i > component_start {
let to_hash = &bytes[component_start..i];
chunk_bits = chunk_bits.wrapping_add(to_hash.len());
chunk_bits = chunk_bits.rotate_right(2);
h.write(to_hash);
}
// skip over separator and optionally a following CurDir item
// since components() would normalize these away.
component_start = i + 1;
let tail = &bytes[component_start..];
if !verbatim {
component_start += match tail {
[b'.'] => 1,
[b'.', sep @ _, ..] if is_sep_byte(*sep) => 1,
_ => 0,
};
}
}
}
if component_start < bytes.len() {
let to_hash = &bytes[component_start..];
chunk_bits = chunk_bits.wrapping_add(to_hash.len());
chunk_bits = chunk_bits.rotate_right(2);
h.write(to_hash);
}
h.write_usize(chunk_bits);
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Eq for Path {}
#[stable(feature = "rust1", since = "1.0.0")]
impl PartialOrd for Path {
#[inline]
fn partial_cmp(&self, other: &Path) -> Option<cmp::Ordering> {
Some(compare_components(self.components(), other.components()))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Ord for Path {
#[inline]
fn cmp(&self, other: &Path) -> cmp::Ordering {
compare_components(self.components(), other.components())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for Path {
#[inline]
fn as_ref(&self) -> &Path {
self
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for OsStr {
#[inline]
fn as_ref(&self) -> &Path {
Path::new(self)
}
}
#[stable(feature = "cow_os_str_as_ref_path", since = "1.8.0")]
impl AsRef<Path> for Cow<'_, OsStr> {
#[inline]
fn as_ref(&self) -> &Path {
Path::new(self)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for OsString {
#[inline]
fn as_ref(&self) -> &Path {
Path::new(self)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for str {
#[inline]
fn as_ref(&self) -> &Path {
Path::new(self)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for String {
#[inline]
fn as_ref(&self) -> &Path {
Path::new(self)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsRef<Path> for PathBuf {
#[inline]
fn as_ref(&self) -> &Path {
self
}
}
#[stable(feature = "path_into_iter", since = "1.6.0")]
impl<'a> IntoIterator for &'a PathBuf {
type Item = &'a OsStr;
type IntoIter = Iter<'a>;
#[inline]
fn into_iter(self) -> Iter<'a> {
self.iter()
}
}
#[stable(feature = "path_into_iter", since = "1.6.0")]
impl<'a> IntoIterator for &'a Path {
type Item = &'a OsStr;
type IntoIter = Iter<'a>;
#[inline]
fn into_iter(self) -> Iter<'a> {
self.iter()
}
}
macro_rules! impl_cmp {
(<$($life:lifetime),*> $lhs:ty, $rhs: ty) => {
#[stable(feature = "partialeq_path", since = "1.6.0")]
impl<$($life),*> PartialEq<$rhs> for $lhs {
#[inline]
fn eq(&self, other: &$rhs) -> bool {
<Path as PartialEq>::eq(self, other)
}
}
#[stable(feature = "partialeq_path", since = "1.6.0")]
impl<$($life),*> PartialEq<$lhs> for $rhs {
#[inline]
fn eq(&self, other: &$lhs) -> bool {
<Path as PartialEq>::eq(self, other)
}
}
#[stable(feature = "cmp_path", since = "1.8.0")]
impl<$($life),*> PartialOrd<$rhs> for $lhs {
#[inline]
fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
<Path as PartialOrd>::partial_cmp(self, other)
}
}
#[stable(feature = "cmp_path", since = "1.8.0")]
impl<$($life),*> PartialOrd<$lhs> for $rhs {
#[inline]
fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
<Path as PartialOrd>::partial_cmp(self, other)
}
}
};
}
impl_cmp!(<> PathBuf, Path);
impl_cmp!(<'a> PathBuf, &'a Path);
impl_cmp!(<'a> Cow<'a, Path>, Path);
impl_cmp!(<'a, 'b> Cow<'a, Path>, &'b Path);
impl_cmp!(<'a> Cow<'a, Path>, PathBuf);
macro_rules! impl_cmp_os_str {
(<$($life:lifetime),*> $lhs:ty, $rhs: ty) => {
#[stable(feature = "cmp_path", since = "1.8.0")]
impl<$($life),*> PartialEq<$rhs> for $lhs {
#[inline]
fn eq(&self, other: &$rhs) -> bool {
<Path as PartialEq>::eq(self, other.as_ref())
}
}
#[stable(feature = "cmp_path", since = "1.8.0")]
impl<$($life),*> PartialEq<$lhs> for $rhs {
#[inline]
fn eq(&self, other: &$lhs) -> bool {
<Path as PartialEq>::eq(self.as_ref(), other)
}
}
#[stable(feature = "cmp_path", since = "1.8.0")]
impl<$($life),*> PartialOrd<$rhs> for $lhs {
#[inline]
fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
<Path as PartialOrd>::partial_cmp(self, other.as_ref())
}
}
#[stable(feature = "cmp_path", since = "1.8.0")]
impl<$($life),*> PartialOrd<$lhs> for $rhs {
#[inline]
fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
<Path as PartialOrd>::partial_cmp(self.as_ref(), other)
}
}
};
}
impl_cmp_os_str!(<> PathBuf, OsStr);
impl_cmp_os_str!(<'a> PathBuf, &'a OsStr);
impl_cmp_os_str!(<'a> PathBuf, Cow<'a, OsStr>);
impl_cmp_os_str!(<> PathBuf, OsString);
impl_cmp_os_str!(<> Path, OsStr);
impl_cmp_os_str!(<'a> Path, &'a OsStr);
impl_cmp_os_str!(<'a> Path, Cow<'a, OsStr>);
impl_cmp_os_str!(<> Path, OsString);
impl_cmp_os_str!(<'a> &'a Path, OsStr);
impl_cmp_os_str!(<'a, 'b> &'a Path, Cow<'b, OsStr>);
impl_cmp_os_str!(<'a> &'a Path, OsString);
impl_cmp_os_str!(<'a> Cow<'a, Path>, OsStr);
impl_cmp_os_str!(<'a, 'b> Cow<'a, Path>, &'b OsStr);
impl_cmp_os_str!(<'a> Cow<'a, Path>, OsString);
#[stable(since = "1.7.0", feature = "strip_prefix")]
impl fmt::Display for StripPrefixError {
#[allow(deprecated, deprecated_in_future)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.description().fmt(f)
}
}
#[stable(since = "1.7.0", feature = "strip_prefix")]
impl Error for StripPrefixError {
#[allow(deprecated)]
fn description(&self) -> &str {
"prefix not found"
}
}
/// Makes the path absolute without accessing the filesystem.
///
/// If the path is relative, the current directory is used as the base directory.
/// All intermediate components will be resolved according to platform-specific
/// rules, but unlike [`canonicalize`][crate::fs::canonicalize], this does not
/// resolve symlinks and may succeed even if the path does not exist.
///
/// If the `path` is empty or getting the
/// [current directory][crate::env::current_dir] fails, then an error will be
/// returned.
///
/// # Platform-specific behavior
///
/// On POSIX platforms, the path is resolved using [POSIX semantics][posix-semantics],
/// except that it stops short of resolving symlinks. This means it will keep `..`
/// components and trailing slashes.
///
/// On Windows, for verbatim paths, this will simply return the path as given. For other
/// paths, this is currently equivalent to calling
/// [`GetFullPathNameW`][windows-path].
///
/// Note that these [may change in the future][changes].
///
/// # Errors
///
/// This function may return an error in the following situations:
///
/// * If `path` is syntactically invalid; in particular, if it is empty.
/// * If getting the [current directory][crate::env::current_dir] fails.
///
/// # Examples
///
/// ## POSIX paths
///
/// ```
/// # #[cfg(unix)]
/// fn main() -> std::io::Result<()> {
/// use std::path::{self, Path};
///
/// // Relative to absolute
/// let absolute = path::absolute("foo/./bar")?;
/// assert!(absolute.ends_with("foo/bar"));
///
/// // Absolute to absolute
/// let absolute = path::absolute("/foo//test/.././bar.rs")?;
/// assert_eq!(absolute, Path::new("/foo/test/../bar.rs"));
/// Ok(())
/// }
/// # #[cfg(not(unix))]
/// # fn main() {}
/// ```
///
/// ## Windows paths
///
/// ```
/// # #[cfg(windows)]
/// fn main() -> std::io::Result<()> {
/// use std::path::{self, Path};
///
/// // Relative to absolute
/// let absolute = path::absolute("foo/./bar")?;
/// assert!(absolute.ends_with(r"foo\bar"));
///
/// // Absolute to absolute
/// let absolute = path::absolute(r"C:\foo//test\..\./bar.rs")?;
///
/// assert_eq!(absolute, Path::new(r"C:\foo\bar.rs"));
/// Ok(())
/// }
/// # #[cfg(not(windows))]
/// # fn main() {}
/// ```
///
/// Note that this [may change in the future][changes].
///
/// [changes]: io#platform-specific-behavior
/// [posix-semantics]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13
/// [windows-path]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfullpathnamew
#[stable(feature = "absolute_path", since = "1.79.0")]
pub fn absolute<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> {
let path = path.as_ref();
if path.as_os_str().is_empty() {
Err(io::const_io_error!(io::ErrorKind::InvalidInput, "cannot make an empty path absolute",))
} else {
sys::path::absolute(path)
}
}