1 //! Cross-platform path manipulation.
3 //! This module provides two types, [`PathBuf`] and [`Path`] (akin to [`String`]
4 //! and [`str`]), for working with paths abstractly. These types are thin wrappers
5 //! around [`OsString`] and [`OsStr`] respectively, meaning that they work directly
6 //! on strings according to the local platform's path syntax.
8 //! Paths can be parsed into [`Component`]s by iterating over the structure
9 //! returned by the [`components`] method on [`Path`]. [`Component`]s roughly
10 //! correspond to the substrings between path separators (`/` or `\`). You can
11 //! reconstruct an equivalent path from components with the [`push`] method on
12 //! [`PathBuf`]; note that the paths may differ syntactically by the
13 //! normalization described in the documentation for the [`components`] method.
17 //! Path manipulation includes both parsing components from slices and building
20 //! To parse a path, you can create a [`Path`] slice from a [`str`]
21 //! slice and start asking questions:
24 //! use std::path::Path;
25 //! use std::ffi::OsStr;
27 //! let path = Path::new("/tmp/foo/bar.txt");
29 //! let parent = path.parent();
30 //! assert_eq!(parent, Some(Path::new("/tmp/foo")));
32 //! let file_stem = path.file_stem();
33 //! assert_eq!(file_stem, Some(OsStr::new("bar")));
35 //! let extension = path.extension();
36 //! assert_eq!(extension, Some(OsStr::new("txt")));
39 //! To build or modify paths, use [`PathBuf`]:
42 //! use std::path::PathBuf;
44 //! // This way works...
45 //! let mut path = PathBuf::from("c:\\");
47 //! path.push("windows");
48 //! path.push("system32");
50 //! path.set_extension("dll");
52 //! // ... but push is best used if you don't know everything up
53 //! // front. If you do, this way is better:
54 //! let path: PathBuf = ["c:\\", "windows", "system32.dll"].iter().collect();
57 //! [`components`]: Path::components
58 //! [`push`]: PathBuf::push
60 #![stable(feature = "rust1", since = "1.0.0")]
61 #![deny(unsafe_op_in_unsafe_fn)]
66 use crate::borrow::{Borrow, Cow};
68 use crate::error::Error;
71 use crate::hash::{Hash, Hasher};
73 use crate::iter::{self, FusedIterator};
74 use crate::ops::{self, Deref};
76 use crate::str::FromStr;
79 use crate::ffi::{OsStr, OsString};
81 use crate::sys::path::{is_sep_byte, is_verbatim_sep, parse_prefix, MAIN_SEP_STR};
83 ////////////////////////////////////////////////////////////////////////////////
85 ////////////////////////////////////////////////////////////////////////////////
87 // Parsing in this module is done by directly transmuting OsStr to [u8] slices,
88 // taking advantage of the fact that OsStr always encodes ASCII characters
89 // as-is. Eventually, this transmutation should be replaced by direct uses of
90 // OsStr APIs for parsing, but it will take a while for those to become
93 ////////////////////////////////////////////////////////////////////////////////
95 ////////////////////////////////////////////////////////////////////////////////
97 /// Windows path prefixes, e.g., `C:` or `\\server\share`.
99 /// Windows uses a variety of path prefix styles, including references to drive
100 /// volumes (like `C:`), network shared folders (like `\\server\share`), and
101 /// others. In addition, some path prefixes are "verbatim" (i.e., prefixed with
102 /// `\\?\`), in which case `/` is *not* treated as a separator and essentially
103 /// no normalization is performed.
108 /// use std::path::{Component, Path, Prefix};
109 /// use std::path::Prefix::*;
110 /// use std::ffi::OsStr;
112 /// fn get_path_prefix(s: &str) -> Prefix {
113 /// let path = Path::new(s);
114 /// match path.components().next().unwrap() {
115 /// Component::Prefix(prefix_component) => prefix_component.kind(),
120 /// # if cfg!(windows) {
121 /// assert_eq!(Verbatim(OsStr::new("pictures")),
122 /// get_path_prefix(r"\\?\pictures\kittens"));
123 /// assert_eq!(VerbatimUNC(OsStr::new("server"), OsStr::new("share")),
124 /// get_path_prefix(r"\\?\UNC\server\share"));
125 /// assert_eq!(VerbatimDisk(b'C'), get_path_prefix(r"\\?\c:\"));
126 /// assert_eq!(DeviceNS(OsStr::new("BrainInterface")),
127 /// get_path_prefix(r"\\.\BrainInterface"));
128 /// assert_eq!(UNC(OsStr::new("server"), OsStr::new("share")),
129 /// get_path_prefix(r"\\server\share"));
130 /// assert_eq!(Disk(b'C'), get_path_prefix(r"C:\Users\Rust\Pictures\Ferris"));
133 #[derive(Copy, Clone, Debug, Hash, PartialOrd, Ord, PartialEq, Eq)]
134 #[stable(feature = "rust1", since = "1.0.0")]
135 pub enum Prefix<'a> {
136 /// Verbatim prefix, e.g., `\\?\cat_pics`.
138 /// Verbatim prefixes consist of `\\?\` immediately followed by the given
140 #[stable(feature = "rust1", since = "1.0.0")]
141 Verbatim(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr),
143 /// Verbatim prefix using Windows' _**U**niform **N**aming **C**onvention_,
144 /// e.g., `\\?\UNC\server\share`.
146 /// Verbatim UNC prefixes consist of `\\?\UNC\` immediately followed by the
147 /// server's hostname and a share name.
148 #[stable(feature = "rust1", since = "1.0.0")]
150 #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
151 #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
154 /// Verbatim disk prefix, e.g., `\\?\C:`.
156 /// Verbatim disk prefixes consist of `\\?\` immediately followed by the
157 /// drive letter and `:`.
158 #[stable(feature = "rust1", since = "1.0.0")]
159 VerbatimDisk(#[stable(feature = "rust1", since = "1.0.0")] u8),
161 /// Device namespace prefix, e.g., `\\.\COM42`.
163 /// Device namespace prefixes consist of `\\.\` immediately followed by the
165 #[stable(feature = "rust1", since = "1.0.0")]
166 DeviceNS(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr),
168 /// Prefix using Windows' _**U**niform **N**aming **C**onvention_, e.g.
169 /// `\\server\share`.
171 /// UNC prefixes consist of the server's hostname and a share name.
172 #[stable(feature = "rust1", since = "1.0.0")]
174 #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
175 #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr,
178 /// Prefix `C:` for the given disk drive.
179 #[stable(feature = "rust1", since = "1.0.0")]
180 Disk(#[stable(feature = "rust1", since = "1.0.0")] u8),
183 impl<'a> Prefix<'a> {
185 fn len(&self) -> usize {
187 fn os_str_len(s: &OsStr) -> usize {
188 os_str_as_u8_slice(s).len()
191 Verbatim(x) => 4 + os_str_len(x),
192 VerbatimUNC(x, y) => {
193 8 + os_str_len(x) + if os_str_len(y) > 0 { 1 + os_str_len(y) } else { 0 }
195 VerbatimDisk(_) => 6,
196 UNC(x, y) => 2 + os_str_len(x) + if os_str_len(y) > 0 { 1 + os_str_len(y) } else { 0 },
197 DeviceNS(x) => 4 + os_str_len(x),
202 /// Determines if the prefix is verbatim, i.e., begins with `\\?\`.
207 /// use std::path::Prefix::*;
208 /// use std::ffi::OsStr;
210 /// assert!(Verbatim(OsStr::new("pictures")).is_verbatim());
211 /// assert!(VerbatimUNC(OsStr::new("server"), OsStr::new("share")).is_verbatim());
212 /// assert!(VerbatimDisk(b'C').is_verbatim());
213 /// assert!(!DeviceNS(OsStr::new("BrainInterface")).is_verbatim());
214 /// assert!(!UNC(OsStr::new("server"), OsStr::new("share")).is_verbatim());
215 /// assert!(!Disk(b'C').is_verbatim());
218 #[stable(feature = "rust1", since = "1.0.0")]
219 pub fn is_verbatim(&self) -> bool {
221 matches!(*self, Verbatim(_) | VerbatimDisk(_) | VerbatimUNC(..))
225 fn is_drive(&self) -> bool {
226 matches!(*self, Prefix::Disk(_))
230 fn has_implicit_root(&self) -> bool {
235 ////////////////////////////////////////////////////////////////////////////////
236 // Exposed parsing helpers
237 ////////////////////////////////////////////////////////////////////////////////
239 /// Determines whether the character is one of the permitted path
240 /// separators for the current platform.
247 /// assert!(path::is_separator('/')); // '/' works for both Unix and Windows
248 /// assert!(!path::is_separator('❤'));
250 #[stable(feature = "rust1", since = "1.0.0")]
251 pub fn is_separator(c: char) -> bool {
252 c.is_ascii() && is_sep_byte(c as u8)
255 /// The primary separator of path components for the current platform.
257 /// For example, `/` on Unix and `\` on Windows.
258 #[stable(feature = "rust1", since = "1.0.0")]
259 pub const MAIN_SEPARATOR: char = crate::sys::path::MAIN_SEP;
261 ////////////////////////////////////////////////////////////////////////////////
263 ////////////////////////////////////////////////////////////////////////////////
265 // Iterate through `iter` while it matches `prefix`; return `None` if `prefix`
266 // is not a prefix of `iter`, otherwise return `Some(iter_after_prefix)` giving
267 // `iter` after having exhausted `prefix`.
268 fn iter_after<'a, 'b, I, J>(mut iter: I, mut prefix: J) -> Option<I>
270 I: Iterator<Item = Component<'a>> + Clone,
271 J: Iterator<Item = Component<'b>>,
274 let mut iter_next = iter.clone();
275 match (iter_next.next(), prefix.next()) {
276 (Some(ref x), Some(ref y)) if x == y => (),
277 (Some(_), Some(_)) => return None,
278 (Some(_), None) => return Some(iter),
279 (None, None) => return Some(iter),
280 (None, Some(_)) => return None,
286 // See note at the top of this module to understand why these are used:
288 // These casts are safe as OsStr is internally a wrapper around [u8] on all
291 // Note that currently this relies on the special knowledge that libstd has;
292 // these types are single-element structs but are not marked repr(transparent)
293 // or repr(C) which would make these casts allowable outside std.
294 fn os_str_as_u8_slice(s: &OsStr) -> &[u8] {
295 unsafe { &*(s as *const OsStr as *const [u8]) }
297 unsafe fn u8_slice_as_os_str(s: &[u8]) -> &OsStr {
298 // SAFETY: see the comment of `os_str_as_u8_slice`
299 unsafe { &*(s as *const [u8] as *const OsStr) }
302 // Detect scheme on Redox
303 fn has_redox_scheme(s: &[u8]) -> bool {
304 cfg!(target_os = "redox") && s.contains(&b':')
307 ////////////////////////////////////////////////////////////////////////////////
308 // Cross-platform, iterator-independent parsing
309 ////////////////////////////////////////////////////////////////////////////////
311 /// Says whether the first byte after the prefix is a separator.
312 fn has_physical_root(s: &[u8], prefix: Option<Prefix<'_>>) -> bool {
313 let path = if let Some(p) = prefix { &s[p.len()..] } else { s };
314 !path.is_empty() && is_sep_byte(path[0])
317 // basic workhorse for splitting stem and extension
318 fn rsplit_file_at_dot(file: &OsStr) -> (Option<&OsStr>, Option<&OsStr>) {
319 if os_str_as_u8_slice(file) == b".." {
320 return (Some(file), None);
323 // The unsafety here stems from converting between &OsStr and &[u8]
324 // and back. This is safe to do because (1) we only look at ASCII
325 // contents of the encoding and (2) new &OsStr values are produced
326 // only from ASCII-bounded slices of existing &OsStr values.
327 let mut iter = os_str_as_u8_slice(file).rsplitn(2, |b| *b == b'.');
328 let after = iter.next();
329 let before = iter.next();
330 if before == Some(b"") {
333 unsafe { (before.map(|s| u8_slice_as_os_str(s)), after.map(|s| u8_slice_as_os_str(s))) }
337 fn split_file_at_dot(file: &OsStr) -> (&OsStr, Option<&OsStr>) {
338 let slice = os_str_as_u8_slice(file);
343 // The unsafety here stems from converting between &OsStr and &[u8]
344 // and back. This is safe to do because (1) we only look at ASCII
345 // contents of the encoding and (2) new &OsStr values are produced
346 // only from ASCII-bounded slices of existing &OsStr values.
347 let i = match slice[1..].iter().position(|b| *b == b'.') {
349 None => return (file, None),
351 let before = &slice[..i];
352 let after = &slice[i + 1..];
353 unsafe { (u8_slice_as_os_str(before), Some(u8_slice_as_os_str(after))) }
356 ////////////////////////////////////////////////////////////////////////////////
357 // The core iterators
358 ////////////////////////////////////////////////////////////////////////////////
360 /// Component parsing works by a double-ended state machine; the cursors at the
361 /// front and back of the path each keep track of what parts of the path have
362 /// been consumed so far.
364 /// Going front to back, a path is made up of a prefix, a starting
365 /// directory component, and a body (of normal components)
366 #[derive(Copy, Clone, PartialEq, PartialOrd, Debug)]
369 StartDir = 1, // / or . or nothing
370 Body = 2, // foo/bar/baz
374 /// A structure wrapping a Windows path prefix as well as its unparsed string
377 /// In addition to the parsed [`Prefix`] information returned by [`kind`],
378 /// `PrefixComponent` also holds the raw and unparsed [`OsStr`] slice,
379 /// returned by [`as_os_str`].
381 /// Instances of this `struct` can be obtained by matching against the
382 /// [`Prefix` variant] on [`Component`].
384 /// Does not occur on Unix.
389 /// # if cfg!(windows) {
390 /// use std::path::{Component, Path, Prefix};
391 /// use std::ffi::OsStr;
393 /// let path = Path::new(r"c:\you\later\");
394 /// match path.components().next().unwrap() {
395 /// Component::Prefix(prefix_component) => {
396 /// assert_eq!(Prefix::Disk(b'C'), prefix_component.kind());
397 /// assert_eq!(OsStr::new("c:"), prefix_component.as_os_str());
399 /// _ => unreachable!(),
404 /// [`as_os_str`]: PrefixComponent::as_os_str
405 /// [`kind`]: PrefixComponent::kind
406 /// [`Prefix` variant]: Component::Prefix
407 #[stable(feature = "rust1", since = "1.0.0")]
408 #[derive(Copy, Clone, Eq, Debug)]
409 pub struct PrefixComponent<'a> {
410 /// The prefix as an unparsed `OsStr` slice.
413 /// The parsed prefix data.
417 impl<'a> PrefixComponent<'a> {
418 /// Returns the parsed prefix data.
420 /// See [`Prefix`]'s documentation for more information on the different
421 /// kinds of prefixes.
422 #[stable(feature = "rust1", since = "1.0.0")]
424 pub fn kind(&self) -> Prefix<'a> {
428 /// Returns the raw [`OsStr`] slice for this prefix.
429 #[stable(feature = "rust1", since = "1.0.0")]
431 pub fn as_os_str(&self) -> &'a OsStr {
436 #[stable(feature = "rust1", since = "1.0.0")]
437 impl<'a> cmp::PartialEq for PrefixComponent<'a> {
439 fn eq(&self, other: &PrefixComponent<'a>) -> bool {
440 cmp::PartialEq::eq(&self.parsed, &other.parsed)
444 #[stable(feature = "rust1", since = "1.0.0")]
445 impl<'a> cmp::PartialOrd for PrefixComponent<'a> {
447 fn partial_cmp(&self, other: &PrefixComponent<'a>) -> Option<cmp::Ordering> {
448 cmp::PartialOrd::partial_cmp(&self.parsed, &other.parsed)
452 #[stable(feature = "rust1", since = "1.0.0")]
453 impl cmp::Ord for PrefixComponent<'_> {
455 fn cmp(&self, other: &Self) -> cmp::Ordering {
456 cmp::Ord::cmp(&self.parsed, &other.parsed)
460 #[stable(feature = "rust1", since = "1.0.0")]
461 impl Hash for PrefixComponent<'_> {
462 fn hash<H: Hasher>(&self, h: &mut H) {
467 /// A single component of a path.
469 /// A `Component` roughly corresponds to a substring between path separators
472 /// This `enum` is created by iterating over [`Components`], which in turn is
473 /// created by the [`components`](Path::components) method on [`Path`].
478 /// use std::path::{Component, Path};
480 /// let path = Path::new("/tmp/foo/bar.txt");
481 /// let components = path.components().collect::<Vec<_>>();
482 /// assert_eq!(&components, &[
483 /// Component::RootDir,
484 /// Component::Normal("tmp".as_ref()),
485 /// Component::Normal("foo".as_ref()),
486 /// Component::Normal("bar.txt".as_ref()),
489 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
490 #[stable(feature = "rust1", since = "1.0.0")]
491 pub enum Component<'a> {
492 /// A Windows path prefix, e.g., `C:` or `\\server\share`.
494 /// There is a large variety of prefix types, see [`Prefix`]'s documentation
497 /// Does not occur on Unix.
498 #[stable(feature = "rust1", since = "1.0.0")]
499 Prefix(#[stable(feature = "rust1", since = "1.0.0")] PrefixComponent<'a>),
501 /// The root directory component, appears after any prefix and before anything else.
503 /// It represents a separator that designates that a path starts from root.
504 #[stable(feature = "rust1", since = "1.0.0")]
507 /// A reference to the current directory, i.e., `.`.
508 #[stable(feature = "rust1", since = "1.0.0")]
511 /// A reference to the parent directory, i.e., `..`.
512 #[stable(feature = "rust1", since = "1.0.0")]
515 /// A normal component, e.g., `a` and `b` in `a/b`.
517 /// This variant is the most common one, it represents references to files
519 #[stable(feature = "rust1", since = "1.0.0")]
520 Normal(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr),
523 impl<'a> Component<'a> {
524 /// Extracts the underlying [`OsStr`] slice.
529 /// use std::path::Path;
531 /// let path = Path::new("./tmp/foo/bar.txt");
532 /// let components: Vec<_> = path.components().map(|comp| comp.as_os_str()).collect();
533 /// assert_eq!(&components, &[".", "tmp", "foo", "bar.txt"]);
535 #[stable(feature = "rust1", since = "1.0.0")]
536 pub fn as_os_str(self) -> &'a OsStr {
538 Component::Prefix(p) => p.as_os_str(),
539 Component::RootDir => OsStr::new(MAIN_SEP_STR),
540 Component::CurDir => OsStr::new("."),
541 Component::ParentDir => OsStr::new(".."),
542 Component::Normal(path) => path,
547 #[stable(feature = "rust1", since = "1.0.0")]
548 impl AsRef<OsStr> for Component<'_> {
550 fn as_ref(&self) -> &OsStr {
555 #[stable(feature = "path_component_asref", since = "1.25.0")]
556 impl AsRef<Path> for Component<'_> {
558 fn as_ref(&self) -> &Path {
559 self.as_os_str().as_ref()
563 /// An iterator over the [`Component`]s of a [`Path`].
565 /// This `struct` is created by the [`components`] method on [`Path`].
566 /// See its documentation for more.
571 /// use std::path::Path;
573 /// let path = Path::new("/tmp/foo/bar.txt");
575 /// for component in path.components() {
576 /// println!("{:?}", component);
580 /// [`components`]: Path::components
582 #[stable(feature = "rust1", since = "1.0.0")]
583 pub struct Components<'a> {
584 // The path left to parse components from
587 // The prefix as it was originally parsed, if any
588 prefix: Option<Prefix<'a>>,
590 // true if path *physically* has a root separator; for most Windows
591 // prefixes, it may have a "logical" root separator for the purposes of
592 // normalization, e.g., \\server\share == \\server\share\.
593 has_physical_root: bool,
595 // The iterator is double-ended, and these two states keep track of what has
596 // been produced from either end
601 /// An iterator over the [`Component`]s of a [`Path`], as [`OsStr`] slices.
603 /// This `struct` is created by the [`iter`] method on [`Path`].
604 /// See its documentation for more.
606 /// [`iter`]: Path::iter
608 #[stable(feature = "rust1", since = "1.0.0")]
609 pub struct Iter<'a> {
610 inner: Components<'a>,
613 #[stable(feature = "path_components_debug", since = "1.13.0")]
614 impl fmt::Debug for Components<'_> {
615 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
616 struct DebugHelper<'a>(&'a Path);
618 impl fmt::Debug for DebugHelper<'_> {
619 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
620 f.debug_list().entries(self.0.components()).finish()
624 f.debug_tuple("Components").field(&DebugHelper(self.as_path())).finish()
628 impl<'a> Components<'a> {
629 // how long is the prefix, if any?
631 fn prefix_len(&self) -> usize {
632 self.prefix.as_ref().map(Prefix::len).unwrap_or(0)
636 fn prefix_verbatim(&self) -> bool {
637 self.prefix.as_ref().map(Prefix::is_verbatim).unwrap_or(false)
640 /// how much of the prefix is left from the point of view of iteration?
642 fn prefix_remaining(&self) -> usize {
643 if self.front == State::Prefix { self.prefix_len() } else { 0 }
646 // Given the iteration so far, how much of the pre-State::Body path is left?
648 fn len_before_body(&self) -> usize {
649 let root = if self.front <= State::StartDir && self.has_physical_root { 1 } else { 0 };
650 let cur_dir = if self.front <= State::StartDir && self.include_cur_dir() { 1 } else { 0 };
651 self.prefix_remaining() + root + cur_dir
654 // is the iteration complete?
656 fn finished(&self) -> bool {
657 self.front == State::Done || self.back == State::Done || self.front > self.back
661 fn is_sep_byte(&self, b: u8) -> bool {
662 if self.prefix_verbatim() { is_verbatim_sep(b) } else { is_sep_byte(b) }
665 /// Extracts a slice corresponding to the portion of the path remaining for iteration.
670 /// use std::path::Path;
672 /// let mut components = Path::new("/tmp/foo/bar.txt").components();
673 /// components.next();
674 /// components.next();
676 /// assert_eq!(Path::new("foo/bar.txt"), components.as_path());
678 #[stable(feature = "rust1", since = "1.0.0")]
679 pub fn as_path(&self) -> &'a Path {
680 let mut comps = self.clone();
681 if comps.front == State::Body {
684 if comps.back == State::Body {
687 unsafe { Path::from_u8_slice(comps.path) }
690 /// Is the *original* path rooted?
691 fn has_root(&self) -> bool {
692 if self.has_physical_root {
695 if let Some(p) = self.prefix {
696 if p.has_implicit_root() {
703 /// Should the normalized path include a leading . ?
704 fn include_cur_dir(&self) -> bool {
708 let mut iter = self.path[self.prefix_len()..].iter();
709 match (iter.next(), iter.next()) {
710 (Some(&b'.'), None) => true,
711 (Some(&b'.'), Some(&b)) => self.is_sep_byte(b),
716 // parse a given byte sequence into the corresponding path component
717 fn parse_single_component<'b>(&self, comp: &'b [u8]) -> Option<Component<'b>> {
719 b"." if self.prefix_verbatim() => Some(Component::CurDir),
720 b"." => None, // . components are normalized away, except at
721 // the beginning of a path, which is treated
722 // separately via `include_cur_dir`
723 b".." => Some(Component::ParentDir),
725 _ => Some(Component::Normal(unsafe { u8_slice_as_os_str(comp) })),
729 // parse a component from the left, saying how many bytes to consume to
730 // remove the component
731 fn parse_next_component(&self) -> (usize, Option<Component<'a>>) {
732 debug_assert!(self.front == State::Body);
733 let (extra, comp) = match self.path.iter().position(|b| self.is_sep_byte(*b)) {
734 None => (0, self.path),
735 Some(i) => (1, &self.path[..i]),
737 (comp.len() + extra, self.parse_single_component(comp))
740 // parse a component from the right, saying how many bytes to consume to
741 // remove the component
742 fn parse_next_component_back(&self) -> (usize, Option<Component<'a>>) {
743 debug_assert!(self.back == State::Body);
744 let start = self.len_before_body();
745 let (extra, comp) = match self.path[start..].iter().rposition(|b| self.is_sep_byte(*b)) {
746 None => (0, &self.path[start..]),
747 Some(i) => (1, &self.path[start + i + 1..]),
749 (comp.len() + extra, self.parse_single_component(comp))
752 // trim away repeated separators (i.e., empty components) on the left
753 fn trim_left(&mut self) {
754 while !self.path.is_empty() {
755 let (size, comp) = self.parse_next_component();
759 self.path = &self.path[size..];
764 // trim away repeated separators (i.e., empty components) on the right
765 fn trim_right(&mut self) {
766 while self.path.len() > self.len_before_body() {
767 let (size, comp) = self.parse_next_component_back();
771 self.path = &self.path[..self.path.len() - size];
777 #[stable(feature = "rust1", since = "1.0.0")]
778 impl AsRef<Path> for Components<'_> {
780 fn as_ref(&self) -> &Path {
785 #[stable(feature = "rust1", since = "1.0.0")]
786 impl AsRef<OsStr> for Components<'_> {
788 fn as_ref(&self) -> &OsStr {
789 self.as_path().as_os_str()
793 #[stable(feature = "path_iter_debug", since = "1.13.0")]
794 impl fmt::Debug for Iter<'_> {
795 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
796 struct DebugHelper<'a>(&'a Path);
798 impl fmt::Debug for DebugHelper<'_> {
799 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
800 f.debug_list().entries(self.0.iter()).finish()
804 f.debug_tuple("Iter").field(&DebugHelper(self.as_path())).finish()
809 /// Extracts a slice corresponding to the portion of the path remaining for iteration.
814 /// use std::path::Path;
816 /// let mut iter = Path::new("/tmp/foo/bar.txt").iter();
820 /// assert_eq!(Path::new("foo/bar.txt"), iter.as_path());
822 #[stable(feature = "rust1", since = "1.0.0")]
824 pub fn as_path(&self) -> &'a Path {
829 #[stable(feature = "rust1", since = "1.0.0")]
830 impl AsRef<Path> for Iter<'_> {
832 fn as_ref(&self) -> &Path {
837 #[stable(feature = "rust1", since = "1.0.0")]
838 impl AsRef<OsStr> for Iter<'_> {
840 fn as_ref(&self) -> &OsStr {
841 self.as_path().as_os_str()
845 #[stable(feature = "rust1", since = "1.0.0")]
846 impl<'a> Iterator for Iter<'a> {
847 type Item = &'a OsStr;
850 fn next(&mut self) -> Option<&'a OsStr> {
851 self.inner.next().map(Component::as_os_str)
855 #[stable(feature = "rust1", since = "1.0.0")]
856 impl<'a> DoubleEndedIterator for Iter<'a> {
858 fn next_back(&mut self) -> Option<&'a OsStr> {
859 self.inner.next_back().map(Component::as_os_str)
863 #[stable(feature = "fused", since = "1.26.0")]
864 impl FusedIterator for Iter<'_> {}
866 #[stable(feature = "rust1", since = "1.0.0")]
867 impl<'a> Iterator for Components<'a> {
868 type Item = Component<'a>;
870 fn next(&mut self) -> Option<Component<'a>> {
871 while !self.finished() {
873 State::Prefix if self.prefix_len() > 0 => {
874 self.front = State::StartDir;
875 debug_assert!(self.prefix_len() <= self.path.len());
876 let raw = &self.path[..self.prefix_len()];
877 self.path = &self.path[self.prefix_len()..];
878 return Some(Component::Prefix(PrefixComponent {
879 raw: unsafe { u8_slice_as_os_str(raw) },
880 parsed: self.prefix.unwrap(),
884 self.front = State::StartDir;
887 self.front = State::Body;
888 if self.has_physical_root {
889 debug_assert!(!self.path.is_empty());
890 self.path = &self.path[1..];
891 return Some(Component::RootDir);
892 } else if let Some(p) = self.prefix {
893 if p.has_implicit_root() && !p.is_verbatim() {
894 return Some(Component::RootDir);
896 } else if self.include_cur_dir() {
897 debug_assert!(!self.path.is_empty());
898 self.path = &self.path[1..];
899 return Some(Component::CurDir);
902 State::Body if !self.path.is_empty() => {
903 let (size, comp) = self.parse_next_component();
904 self.path = &self.path[size..];
910 self.front = State::Done;
912 State::Done => unreachable!(),
919 #[stable(feature = "rust1", since = "1.0.0")]
920 impl<'a> DoubleEndedIterator for Components<'a> {
921 fn next_back(&mut self) -> Option<Component<'a>> {
922 while !self.finished() {
924 State::Body if self.path.len() > self.len_before_body() => {
925 let (size, comp) = self.parse_next_component_back();
926 self.path = &self.path[..self.path.len() - size];
932 self.back = State::StartDir;
935 self.back = State::Prefix;
936 if self.has_physical_root {
937 self.path = &self.path[..self.path.len() - 1];
938 return Some(Component::RootDir);
939 } else if let Some(p) = self.prefix {
940 if p.has_implicit_root() && !p.is_verbatim() {
941 return Some(Component::RootDir);
943 } else if self.include_cur_dir() {
944 self.path = &self.path[..self.path.len() - 1];
945 return Some(Component::CurDir);
948 State::Prefix if self.prefix_len() > 0 => {
949 self.back = State::Done;
950 return Some(Component::Prefix(PrefixComponent {
951 raw: unsafe { u8_slice_as_os_str(self.path) },
952 parsed: self.prefix.unwrap(),
956 self.back = State::Done;
959 State::Done => unreachable!(),
966 #[stable(feature = "fused", since = "1.26.0")]
967 impl FusedIterator for Components<'_> {}
969 #[stable(feature = "rust1", since = "1.0.0")]
970 impl<'a> cmp::PartialEq for Components<'a> {
972 fn eq(&self, other: &Components<'a>) -> bool {
973 Iterator::eq(self.clone().rev(), other.clone().rev())
977 #[stable(feature = "rust1", since = "1.0.0")]
978 impl cmp::Eq for Components<'_> {}
980 #[stable(feature = "rust1", since = "1.0.0")]
981 impl<'a> cmp::PartialOrd for Components<'a> {
983 fn partial_cmp(&self, other: &Components<'a>) -> Option<cmp::Ordering> {
984 Some(compare_components(self.clone(), other.clone()))
988 #[stable(feature = "rust1", since = "1.0.0")]
989 impl cmp::Ord for Components<'_> {
991 fn cmp(&self, other: &Self) -> cmp::Ordering {
992 compare_components(self.clone(), other.clone())
996 fn compare_components(mut left: Components<'_>, mut right: Components<'_>) -> cmp::Ordering {
997 // Fast path for long shared prefixes
999 // - compare raw bytes to find first mismatch
1000 // - backtrack to find separator before mismatch to avoid ambiguous parsings of '.' or '..' characters
1001 // - if found update state to only do a component-wise comparison on the remainder,
1002 // otherwise do it on the full path
1004 // The fast path isn't taken for paths with a PrefixComponent to avoid backtracking into
1005 // the middle of one
1006 if left.prefix.is_none() && right.prefix.is_none() && left.front == right.front {
1007 // this might benefit from a [u8]::first_mismatch simd implementation, if it existed
1008 let first_difference =
1009 match left.path.iter().zip(right.path.iter()).position(|(&a, &b)| a != b) {
1010 None if left.path.len() == right.path.len() => return cmp::Ordering::Equal,
1011 None => left.path.len().min(right.path.len()),
1015 if let Some(previous_sep) =
1016 left.path[..first_difference].iter().rposition(|&b| left.is_sep_byte(b))
1018 let mismatched_component_start = previous_sep + 1;
1019 left.path = &left.path[mismatched_component_start..];
1020 left.front = State::Body;
1021 right.path = &right.path[mismatched_component_start..];
1022 right.front = State::Body;
1026 Iterator::cmp(left, right)
1029 /// An iterator over [`Path`] and its ancestors.
1031 /// This `struct` is created by the [`ancestors`] method on [`Path`].
1032 /// See its documentation for more.
1037 /// use std::path::Path;
1039 /// let path = Path::new("/foo/bar");
1041 /// for ancestor in path.ancestors() {
1042 /// println!("{}", ancestor.display());
1046 /// [`ancestors`]: Path::ancestors
1047 #[derive(Copy, Clone, Debug)]
1048 #[stable(feature = "path_ancestors", since = "1.28.0")]
1049 pub struct Ancestors<'a> {
1050 next: Option<&'a Path>,
1053 #[stable(feature = "path_ancestors", since = "1.28.0")]
1054 impl<'a> Iterator for Ancestors<'a> {
1055 type Item = &'a Path;
1058 fn next(&mut self) -> Option<Self::Item> {
1059 let next = self.next;
1060 self.next = next.and_then(Path::parent);
1065 #[stable(feature = "path_ancestors", since = "1.28.0")]
1066 impl FusedIterator for Ancestors<'_> {}
1068 ////////////////////////////////////////////////////////////////////////////////
1069 // Basic types and traits
1070 ////////////////////////////////////////////////////////////////////////////////
1072 /// An owned, mutable path (akin to [`String`]).
1074 /// This type provides methods like [`push`] and [`set_extension`] that mutate
1075 /// the path in place. It also implements [`Deref`] to [`Path`], meaning that
1076 /// all methods on [`Path`] slices are available on `PathBuf` values as well.
1078 /// [`push`]: PathBuf::push
1079 /// [`set_extension`]: PathBuf::set_extension
1081 /// More details about the overall approach can be found in
1082 /// the [module documentation](self).
1086 /// You can use [`push`] to build up a `PathBuf` from
1090 /// use std::path::PathBuf;
1092 /// let mut path = PathBuf::new();
1094 /// path.push(r"C:\");
1095 /// path.push("windows");
1096 /// path.push("system32");
1098 /// path.set_extension("dll");
1101 /// However, [`push`] is best used for dynamic situations. This is a better way
1102 /// to do this when you know all of the components ahead of time:
1105 /// use std::path::PathBuf;
1107 /// let path: PathBuf = [r"C:\", "windows", "system32.dll"].iter().collect();
1110 /// We can still do better than this! Since these are all strings, we can use
1114 /// use std::path::PathBuf;
1116 /// let path = PathBuf::from(r"C:\windows\system32.dll");
1119 /// Which method works best depends on what kind of situation you're in.
1120 #[cfg_attr(not(test), rustc_diagnostic_item = "PathBuf")]
1121 #[stable(feature = "rust1", since = "1.0.0")]
1123 // `PathBuf::as_mut_vec` current implementation relies
1124 // on `PathBuf` being layout-compatible with `Vec<u8>`.
1125 // When attribute privacy is implemented, `PathBuf` should be annotated as `#[repr(transparent)]`.
1126 // Anyway, `PathBuf` representation and layout are considered implementation detail, are
1127 // not documented and must not be relied upon.
1128 pub struct PathBuf {
1134 fn as_mut_vec(&mut self) -> &mut Vec<u8> {
1135 unsafe { &mut *(self as *mut PathBuf as *mut Vec<u8>) }
1138 /// Allocates an empty `PathBuf`.
1143 /// use std::path::PathBuf;
1145 /// let path = PathBuf::new();
1147 #[stable(feature = "rust1", since = "1.0.0")]
1149 pub fn new() -> PathBuf {
1150 PathBuf { inner: OsString::new() }
1153 /// Creates a new `PathBuf` with a given capacity used to create the
1154 /// internal [`OsString`]. See [`with_capacity`] defined on [`OsString`].
1159 /// use std::path::PathBuf;
1161 /// let mut path = PathBuf::with_capacity(10);
1162 /// let capacity = path.capacity();
1164 /// // This push is done without reallocating
1165 /// path.push(r"C:\");
1167 /// assert_eq!(capacity, path.capacity());
1170 /// [`with_capacity`]: OsString::with_capacity
1171 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1173 pub fn with_capacity(capacity: usize) -> PathBuf {
1174 PathBuf { inner: OsString::with_capacity(capacity) }
1177 /// Coerces to a [`Path`] slice.
1182 /// use std::path::{Path, PathBuf};
1184 /// let p = PathBuf::from("/test");
1185 /// assert_eq!(Path::new("/test"), p.as_path());
1187 #[stable(feature = "rust1", since = "1.0.0")]
1189 pub fn as_path(&self) -> &Path {
1193 /// Extends `self` with `path`.
1195 /// If `path` is absolute, it replaces the current path.
1199 /// * if `path` has a root but no prefix (e.g., `\windows`), it
1200 /// replaces everything except for the prefix (if any) of `self`.
1201 /// * if `path` has a prefix but no root, it replaces `self`.
1205 /// Pushing a relative path extends the existing path:
1208 /// use std::path::PathBuf;
1210 /// let mut path = PathBuf::from("/tmp");
1211 /// path.push("file.bk");
1212 /// assert_eq!(path, PathBuf::from("/tmp/file.bk"));
1215 /// Pushing an absolute path replaces the existing path:
1218 /// use std::path::PathBuf;
1220 /// let mut path = PathBuf::from("/tmp");
1221 /// path.push("/etc");
1222 /// assert_eq!(path, PathBuf::from("/etc"));
1224 #[stable(feature = "rust1", since = "1.0.0")]
1225 pub fn push<P: AsRef<Path>>(&mut self, path: P) {
1226 self._push(path.as_ref())
1229 fn _push(&mut self, path: &Path) {
1230 // in general, a separator is needed if the rightmost byte is not a separator
1231 let mut need_sep = self.as_mut_vec().last().map(|c| !is_sep_byte(*c)).unwrap_or(false);
1233 // in the special case of `C:` on Windows, do *not* add a separator
1234 let comps = self.components();
1236 if comps.prefix_len() > 0
1237 && comps.prefix_len() == comps.path.len()
1238 && comps.prefix.unwrap().is_drive()
1243 // absolute `path` replaces `self`
1244 if path.is_absolute() || path.prefix().is_some() {
1245 self.as_mut_vec().truncate(0);
1247 // verbatim paths need . and .. removed
1248 } else if comps.prefix_verbatim() {
1249 let mut buf: Vec<_> = comps.collect();
1250 for c in path.components() {
1252 Component::RootDir => {
1256 Component::CurDir => (),
1257 Component::ParentDir => {
1258 if let Some(Component::Normal(_)) = buf.last() {
1266 let mut res = OsString::new();
1267 let mut need_sep = false;
1270 if need_sep && c != Component::RootDir {
1271 res.push(MAIN_SEP_STR);
1273 res.push(c.as_os_str());
1275 need_sep = match c {
1276 Component::RootDir => false,
1277 Component::Prefix(prefix) => {
1278 !prefix.parsed.is_drive() && prefix.parsed.len() > 0
1287 // `path` has a root but no prefix, e.g., `\windows` (Windows only)
1288 } else if path.has_root() {
1289 let prefix_len = self.components().prefix_remaining();
1290 self.as_mut_vec().truncate(prefix_len);
1292 // `path` is a pure relative path
1293 } else if need_sep {
1294 self.inner.push(MAIN_SEP_STR);
1297 self.inner.push(path);
1300 /// Truncates `self` to [`self.parent`].
1302 /// Returns `false` and does nothing if [`self.parent`] is [`None`].
1303 /// Otherwise, returns `true`.
1305 /// [`self.parent`]: Path::parent
1310 /// use std::path::{Path, PathBuf};
1312 /// let mut p = PathBuf::from("/spirited/away.rs");
1315 /// assert_eq!(Path::new("/spirited"), p);
1317 /// assert_eq!(Path::new("/"), p);
1319 #[stable(feature = "rust1", since = "1.0.0")]
1320 pub fn pop(&mut self) -> bool {
1321 match self.parent().map(|p| p.as_u8_slice().len()) {
1323 self.as_mut_vec().truncate(len);
1330 /// Updates [`self.file_name`] to `file_name`.
1332 /// If [`self.file_name`] was [`None`], this is equivalent to pushing
1335 /// Otherwise it is equivalent to calling [`pop`] and then pushing
1336 /// `file_name`. The new path will be a sibling of the original path.
1337 /// (That is, it will have the same parent.)
1339 /// [`self.file_name`]: Path::file_name
1340 /// [`pop`]: PathBuf::pop
1345 /// use std::path::PathBuf;
1347 /// let mut buf = PathBuf::from("/");
1348 /// assert!(buf.file_name() == None);
1349 /// buf.set_file_name("bar");
1350 /// assert!(buf == PathBuf::from("/bar"));
1351 /// assert!(buf.file_name().is_some());
1352 /// buf.set_file_name("baz.txt");
1353 /// assert!(buf == PathBuf::from("/baz.txt"));
1355 #[stable(feature = "rust1", since = "1.0.0")]
1356 pub fn set_file_name<S: AsRef<OsStr>>(&mut self, file_name: S) {
1357 self._set_file_name(file_name.as_ref())
1360 fn _set_file_name(&mut self, file_name: &OsStr) {
1361 if self.file_name().is_some() {
1362 let popped = self.pop();
1363 debug_assert!(popped);
1365 self.push(file_name);
1368 /// Updates [`self.extension`] to `extension`.
1370 /// Returns `false` and does nothing if [`self.file_name`] is [`None`],
1371 /// returns `true` and updates the extension otherwise.
1373 /// If [`self.extension`] is [`None`], the extension is added; otherwise
1376 /// [`self.file_name`]: Path::file_name
1377 /// [`self.extension`]: Path::extension
1382 /// use std::path::{Path, PathBuf};
1384 /// let mut p = PathBuf::from("/feel/the");
1386 /// p.set_extension("force");
1387 /// assert_eq!(Path::new("/feel/the.force"), p.as_path());
1389 /// p.set_extension("dark_side");
1390 /// assert_eq!(Path::new("/feel/the.dark_side"), p.as_path());
1392 #[stable(feature = "rust1", since = "1.0.0")]
1393 pub fn set_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> bool {
1394 self._set_extension(extension.as_ref())
1397 fn _set_extension(&mut self, extension: &OsStr) -> bool {
1398 let file_stem = match self.file_stem() {
1399 None => return false,
1400 Some(f) => os_str_as_u8_slice(f),
1403 // truncate until right after the file stem
1404 let end_file_stem = file_stem[file_stem.len()..].as_ptr() as usize;
1405 let start = os_str_as_u8_slice(&self.inner).as_ptr() as usize;
1406 let v = self.as_mut_vec();
1407 v.truncate(end_file_stem.wrapping_sub(start));
1409 // add the new extension, if any
1410 let new = os_str_as_u8_slice(extension);
1411 if !new.is_empty() {
1412 v.reserve_exact(new.len() + 1);
1414 v.extend_from_slice(new);
1420 /// Consumes the `PathBuf`, yielding its internal [`OsString`] storage.
1425 /// use std::path::PathBuf;
1427 /// let p = PathBuf::from("/the/head");
1428 /// let os_str = p.into_os_string();
1430 #[stable(feature = "rust1", since = "1.0.0")]
1432 pub fn into_os_string(self) -> OsString {
1436 /// Converts this `PathBuf` into a [boxed](Box) [`Path`].
1437 #[stable(feature = "into_boxed_path", since = "1.20.0")]
1439 pub fn into_boxed_path(self) -> Box<Path> {
1440 let rw = Box::into_raw(self.inner.into_boxed_os_str()) as *mut Path;
1441 unsafe { Box::from_raw(rw) }
1444 /// Invokes [`capacity`] on the underlying instance of [`OsString`].
1446 /// [`capacity`]: OsString::capacity
1447 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1449 pub fn capacity(&self) -> usize {
1450 self.inner.capacity()
1453 /// Invokes [`clear`] on the underlying instance of [`OsString`].
1455 /// [`clear`]: OsString::clear
1456 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1458 pub fn clear(&mut self) {
1462 /// Invokes [`reserve`] on the underlying instance of [`OsString`].
1464 /// [`reserve`]: OsString::reserve
1465 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1467 pub fn reserve(&mut self, additional: usize) {
1468 self.inner.reserve(additional)
1471 /// Invokes [`reserve_exact`] on the underlying instance of [`OsString`].
1473 /// [`reserve_exact`]: OsString::reserve_exact
1474 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1476 pub fn reserve_exact(&mut self, additional: usize) {
1477 self.inner.reserve_exact(additional)
1480 /// Invokes [`shrink_to_fit`] on the underlying instance of [`OsString`].
1482 /// [`shrink_to_fit`]: OsString::shrink_to_fit
1483 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1485 pub fn shrink_to_fit(&mut self) {
1486 self.inner.shrink_to_fit()
1489 /// Invokes [`shrink_to`] on the underlying instance of [`OsString`].
1491 /// [`shrink_to`]: OsString::shrink_to
1492 #[stable(feature = "shrink_to", since = "1.56.0")]
1494 pub fn shrink_to(&mut self, min_capacity: usize) {
1495 self.inner.shrink_to(min_capacity)
1499 #[stable(feature = "rust1", since = "1.0.0")]
1500 impl Clone for PathBuf {
1502 fn clone(&self) -> Self {
1503 PathBuf { inner: self.inner.clone() }
1507 fn clone_from(&mut self, source: &Self) {
1508 self.inner.clone_from(&source.inner)
1512 #[stable(feature = "box_from_path", since = "1.17.0")]
1513 impl From<&Path> for Box<Path> {
1514 /// Creates a boxed [`Path`] from a reference.
1516 /// This will allocate and clone `path` to it.
1517 fn from(path: &Path) -> Box<Path> {
1518 let boxed: Box<OsStr> = path.inner.into();
1519 let rw = Box::into_raw(boxed) as *mut Path;
1520 unsafe { Box::from_raw(rw) }
1524 #[stable(feature = "box_from_cow", since = "1.45.0")]
1525 impl From<Cow<'_, Path>> for Box<Path> {
1526 /// Creates a boxed [`Path`] from a clone-on-write pointer.
1528 /// Converting from a `Cow::Owned` does not clone or allocate.
1530 fn from(cow: Cow<'_, Path>) -> Box<Path> {
1532 Cow::Borrowed(path) => Box::from(path),
1533 Cow::Owned(path) => Box::from(path),
1538 #[stable(feature = "path_buf_from_box", since = "1.18.0")]
1539 impl From<Box<Path>> for PathBuf {
1540 /// Converts a `Box<Path>` into a `PathBuf`
1542 /// This conversion does not allocate or copy memory.
1544 fn from(boxed: Box<Path>) -> PathBuf {
1545 boxed.into_path_buf()
1549 #[stable(feature = "box_from_path_buf", since = "1.20.0")]
1550 impl From<PathBuf> for Box<Path> {
1551 /// Converts a `PathBuf` into a `Box<Path>`
1553 /// This conversion currently should not allocate memory,
1554 /// but this behavior is not guaranteed on all platforms or in all future versions.
1556 fn from(p: PathBuf) -> Box<Path> {
1561 #[stable(feature = "more_box_slice_clone", since = "1.29.0")]
1562 impl Clone for Box<Path> {
1564 fn clone(&self) -> Self {
1565 self.to_path_buf().into_boxed_path()
1569 #[stable(feature = "rust1", since = "1.0.0")]
1570 impl<T: ?Sized + AsRef<OsStr>> From<&T> for PathBuf {
1571 /// Converts a borrowed `OsStr` to a `PathBuf`.
1573 /// Allocates a [`PathBuf`] and copies the data into it.
1575 fn from(s: &T) -> PathBuf {
1576 PathBuf::from(s.as_ref().to_os_string())
1580 #[stable(feature = "rust1", since = "1.0.0")]
1581 impl From<OsString> for PathBuf {
1582 /// Converts an [`OsString`] into a [`PathBuf`]
1584 /// This conversion does not allocate or copy memory.
1586 fn from(s: OsString) -> PathBuf {
1587 PathBuf { inner: s }
1591 #[stable(feature = "from_path_buf_for_os_string", since = "1.14.0")]
1592 impl From<PathBuf> for OsString {
1593 /// Converts a [`PathBuf`] into an [`OsString`]
1595 /// This conversion does not allocate or copy memory.
1597 fn from(path_buf: PathBuf) -> OsString {
1602 #[stable(feature = "rust1", since = "1.0.0")]
1603 impl From<String> for PathBuf {
1604 /// Converts a [`String`] into a [`PathBuf`]
1606 /// This conversion does not allocate or copy memory.
1608 fn from(s: String) -> PathBuf {
1609 PathBuf::from(OsString::from(s))
1613 #[stable(feature = "path_from_str", since = "1.32.0")]
1614 impl FromStr for PathBuf {
1615 type Err = core::convert::Infallible;
1618 fn from_str(s: &str) -> Result<Self, Self::Err> {
1619 Ok(PathBuf::from(s))
1623 #[stable(feature = "rust1", since = "1.0.0")]
1624 impl<P: AsRef<Path>> iter::FromIterator<P> for PathBuf {
1625 fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> PathBuf {
1626 let mut buf = PathBuf::new();
1632 #[stable(feature = "rust1", since = "1.0.0")]
1633 impl<P: AsRef<Path>> iter::Extend<P> for PathBuf {
1634 fn extend<I: IntoIterator<Item = P>>(&mut self, iter: I) {
1635 iter.into_iter().for_each(move |p| self.push(p.as_ref()));
1639 fn extend_one(&mut self, p: P) {
1640 self.push(p.as_ref());
1644 #[stable(feature = "rust1", since = "1.0.0")]
1645 impl fmt::Debug for PathBuf {
1646 fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
1647 fmt::Debug::fmt(&**self, formatter)
1651 #[stable(feature = "rust1", since = "1.0.0")]
1652 impl ops::Deref for PathBuf {
1655 fn deref(&self) -> &Path {
1656 Path::new(&self.inner)
1660 #[stable(feature = "rust1", since = "1.0.0")]
1661 impl Borrow<Path> for PathBuf {
1663 fn borrow(&self) -> &Path {
1668 #[stable(feature = "default_for_pathbuf", since = "1.17.0")]
1669 impl Default for PathBuf {
1671 fn default() -> Self {
1676 #[stable(feature = "cow_from_path", since = "1.6.0")]
1677 impl<'a> From<&'a Path> for Cow<'a, Path> {
1678 /// Creates a clone-on-write pointer from a reference to
1681 /// This conversion does not clone or allocate.
1683 fn from(s: &'a Path) -> Cow<'a, Path> {
1688 #[stable(feature = "cow_from_path", since = "1.6.0")]
1689 impl<'a> From<PathBuf> for Cow<'a, Path> {
1690 /// Creates a clone-on-write pointer from an owned
1691 /// instance of [`PathBuf`].
1693 /// This conversion does not clone or allocate.
1695 fn from(s: PathBuf) -> Cow<'a, Path> {
1700 #[stable(feature = "cow_from_pathbuf_ref", since = "1.28.0")]
1701 impl<'a> From<&'a PathBuf> for Cow<'a, Path> {
1702 /// Creates a clone-on-write pointer from a reference to
1705 /// This conversion does not clone or allocate.
1707 fn from(p: &'a PathBuf) -> Cow<'a, Path> {
1708 Cow::Borrowed(p.as_path())
1712 #[stable(feature = "pathbuf_from_cow_path", since = "1.28.0")]
1713 impl<'a> From<Cow<'a, Path>> for PathBuf {
1714 /// Converts a clone-on-write pointer to an owned path.
1716 /// Converting from a `Cow::Owned` does not clone or allocate.
1718 fn from(p: Cow<'a, Path>) -> Self {
1723 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1724 impl From<PathBuf> for Arc<Path> {
1725 /// Converts a [`PathBuf`] into an [`Arc`] by moving the [`PathBuf`] data into a new [`Arc`] buffer.
1727 fn from(s: PathBuf) -> Arc<Path> {
1728 let arc: Arc<OsStr> = Arc::from(s.into_os_string());
1729 unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) }
1733 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1734 impl From<&Path> for Arc<Path> {
1735 /// Converts a [`Path`] into an [`Arc`] by copying the [`Path`] data into a new [`Arc`] buffer.
1737 fn from(s: &Path) -> Arc<Path> {
1738 let arc: Arc<OsStr> = Arc::from(s.as_os_str());
1739 unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) }
1743 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1744 impl From<PathBuf> for Rc<Path> {
1745 /// Converts a [`PathBuf`] into an [`Rc`] by moving the [`PathBuf`] data into a new `Rc` buffer.
1747 fn from(s: PathBuf) -> Rc<Path> {
1748 let rc: Rc<OsStr> = Rc::from(s.into_os_string());
1749 unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) }
1753 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1754 impl From<&Path> for Rc<Path> {
1755 /// Converts a [`Path`] into an [`Rc`] by copying the [`Path`] data into a new `Rc` buffer.
1757 fn from(s: &Path) -> Rc<Path> {
1758 let rc: Rc<OsStr> = Rc::from(s.as_os_str());
1759 unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) }
1763 #[stable(feature = "rust1", since = "1.0.0")]
1764 impl ToOwned for Path {
1765 type Owned = PathBuf;
1767 fn to_owned(&self) -> PathBuf {
1771 fn clone_into(&self, target: &mut PathBuf) {
1772 self.inner.clone_into(&mut target.inner);
1776 #[stable(feature = "rust1", since = "1.0.0")]
1777 impl cmp::PartialEq for PathBuf {
1779 fn eq(&self, other: &PathBuf) -> bool {
1780 self.components() == other.components()
1784 #[stable(feature = "rust1", since = "1.0.0")]
1785 impl Hash for PathBuf {
1786 fn hash<H: Hasher>(&self, h: &mut H) {
1787 self.as_path().hash(h)
1791 #[stable(feature = "rust1", since = "1.0.0")]
1792 impl cmp::Eq for PathBuf {}
1794 #[stable(feature = "rust1", since = "1.0.0")]
1795 impl cmp::PartialOrd for PathBuf {
1797 fn partial_cmp(&self, other: &PathBuf) -> Option<cmp::Ordering> {
1798 Some(compare_components(self.components(), other.components()))
1802 #[stable(feature = "rust1", since = "1.0.0")]
1803 impl cmp::Ord for PathBuf {
1805 fn cmp(&self, other: &PathBuf) -> cmp::Ordering {
1806 compare_components(self.components(), other.components())
1810 #[stable(feature = "rust1", since = "1.0.0")]
1811 impl AsRef<OsStr> for PathBuf {
1813 fn as_ref(&self) -> &OsStr {
1818 /// A slice of a path (akin to [`str`]).
1820 /// This type supports a number of operations for inspecting a path, including
1821 /// breaking the path into its components (separated by `/` on Unix and by either
1822 /// `/` or `\` on Windows), extracting the file name, determining whether the path
1823 /// is absolute, and so on.
1825 /// This is an *unsized* type, meaning that it must always be used behind a
1826 /// pointer like `&` or [`Box`]. For an owned version of this type,
1827 /// see [`PathBuf`].
1829 /// More details about the overall approach can be found in
1830 /// the [module documentation](self).
1835 /// use std::path::Path;
1836 /// use std::ffi::OsStr;
1838 /// // Note: this example does work on Windows
1839 /// let path = Path::new("./foo/bar.txt");
1841 /// let parent = path.parent();
1842 /// assert_eq!(parent, Some(Path::new("./foo")));
1844 /// let file_stem = path.file_stem();
1845 /// assert_eq!(file_stem, Some(OsStr::new("bar")));
1847 /// let extension = path.extension();
1848 /// assert_eq!(extension, Some(OsStr::new("txt")));
1850 #[cfg_attr(not(test), rustc_diagnostic_item = "Path")]
1851 #[stable(feature = "rust1", since = "1.0.0")]
1853 // `Path::new` current implementation relies
1854 // on `Path` being layout-compatible with `OsStr`.
1855 // When attribute privacy is implemented, `Path` should be annotated as `#[repr(transparent)]`.
1856 // Anyway, `Path` representation and layout are considered implementation detail, are
1857 // not documented and must not be relied upon.
1862 /// An error returned from [`Path::strip_prefix`] if the prefix was not found.
1864 /// This `struct` is created by the [`strip_prefix`] method on [`Path`].
1865 /// See its documentation for more.
1867 /// [`strip_prefix`]: Path::strip_prefix
1868 #[derive(Debug, Clone, PartialEq, Eq)]
1869 #[stable(since = "1.7.0", feature = "strip_prefix")]
1870 pub struct StripPrefixError(());
1873 // The following (private!) function allows construction of a path from a u8
1874 // slice, which is only safe when it is known to follow the OsStr encoding.
1875 unsafe fn from_u8_slice(s: &[u8]) -> &Path {
1876 unsafe { Path::new(u8_slice_as_os_str(s)) }
1878 // The following (private!) function reveals the byte encoding used for OsStr.
1879 fn as_u8_slice(&self) -> &[u8] {
1880 os_str_as_u8_slice(&self.inner)
1883 /// Directly wraps a string slice as a `Path` slice.
1885 /// This is a cost-free conversion.
1890 /// use std::path::Path;
1892 /// Path::new("foo.txt");
1895 /// You can create `Path`s from `String`s, or even other `Path`s:
1898 /// use std::path::Path;
1900 /// let string = String::from("foo.txt");
1901 /// let from_string = Path::new(&string);
1902 /// let from_path = Path::new(&from_string);
1903 /// assert_eq!(from_string, from_path);
1905 #[stable(feature = "rust1", since = "1.0.0")]
1906 pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &Path {
1907 unsafe { &*(s.as_ref() as *const OsStr as *const Path) }
1910 /// Yields the underlying [`OsStr`] slice.
1915 /// use std::path::Path;
1917 /// let os_str = Path::new("foo.txt").as_os_str();
1918 /// assert_eq!(os_str, std::ffi::OsStr::new("foo.txt"));
1920 #[stable(feature = "rust1", since = "1.0.0")]
1922 pub fn as_os_str(&self) -> &OsStr {
1926 /// Yields a [`&str`] slice if the `Path` is valid unicode.
1928 /// This conversion may entail doing a check for UTF-8 validity.
1929 /// Note that validation is performed because non-UTF-8 strings are
1930 /// perfectly valid for some OS.
1937 /// use std::path::Path;
1939 /// let path = Path::new("foo.txt");
1940 /// assert_eq!(path.to_str(), Some("foo.txt"));
1942 #[stable(feature = "rust1", since = "1.0.0")]
1944 pub fn to_str(&self) -> Option<&str> {
1948 /// Converts a `Path` to a [`Cow<str>`].
1950 /// Any non-Unicode sequences are replaced with
1951 /// [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD].
1953 /// [U+FFFD]: super::char::REPLACEMENT_CHARACTER
1957 /// Calling `to_string_lossy` on a `Path` with valid unicode:
1960 /// use std::path::Path;
1962 /// let path = Path::new("foo.txt");
1963 /// assert_eq!(path.to_string_lossy(), "foo.txt");
1966 /// Had `path` contained invalid unicode, the `to_string_lossy` call might
1967 /// have returned `"fo�.txt"`.
1968 #[stable(feature = "rust1", since = "1.0.0")]
1970 pub fn to_string_lossy(&self) -> Cow<'_, str> {
1971 self.inner.to_string_lossy()
1974 /// Converts a `Path` to an owned [`PathBuf`].
1979 /// use std::path::Path;
1981 /// let path_buf = Path::new("foo.txt").to_path_buf();
1982 /// assert_eq!(path_buf, std::path::PathBuf::from("foo.txt"));
1984 #[rustc_conversion_suggestion]
1985 #[stable(feature = "rust1", since = "1.0.0")]
1986 pub fn to_path_buf(&self) -> PathBuf {
1987 PathBuf::from(self.inner.to_os_string())
1990 /// Returns `true` if the `Path` is absolute, i.e., if it is independent of
1991 /// the current directory.
1993 /// * On Unix, a path is absolute if it starts with the root, so
1994 /// `is_absolute` and [`has_root`] are equivalent.
1996 /// * On Windows, a path is absolute if it has a prefix and starts with the
1997 /// root: `c:\windows` is absolute, while `c:temp` and `\temp` are not.
2002 /// use std::path::Path;
2004 /// assert!(!Path::new("foo.txt").is_absolute());
2007 /// [`has_root`]: Path::has_root
2008 #[stable(feature = "rust1", since = "1.0.0")]
2009 #[allow(deprecated)]
2010 pub fn is_absolute(&self) -> bool {
2011 if cfg!(target_os = "redox") {
2012 // FIXME: Allow Redox prefixes
2013 self.has_root() || has_redox_scheme(self.as_u8_slice())
2015 self.has_root() && (cfg!(any(unix, target_os = "wasi")) || self.prefix().is_some())
2019 /// Returns `true` if the `Path` is relative, i.e., not absolute.
2021 /// See [`is_absolute`]'s documentation for more details.
2026 /// use std::path::Path;
2028 /// assert!(Path::new("foo.txt").is_relative());
2031 /// [`is_absolute`]: Path::is_absolute
2032 #[stable(feature = "rust1", since = "1.0.0")]
2034 pub fn is_relative(&self) -> bool {
2038 fn prefix(&self) -> Option<Prefix<'_>> {
2039 self.components().prefix
2042 /// Returns `true` if the `Path` has a root.
2044 /// * On Unix, a path has a root if it begins with `/`.
2046 /// * On Windows, a path has a root if it:
2047 /// * has no prefix and begins with a separator, e.g., `\windows`
2048 /// * has a prefix followed by a separator, e.g., `c:\windows` but not `c:windows`
2049 /// * has any non-disk prefix, e.g., `\\server\share`
2054 /// use std::path::Path;
2056 /// assert!(Path::new("/etc/passwd").has_root());
2058 #[stable(feature = "rust1", since = "1.0.0")]
2060 pub fn has_root(&self) -> bool {
2061 self.components().has_root()
2064 /// Returns the `Path` without its final component, if there is one.
2066 /// Returns [`None`] if the path terminates in a root or prefix.
2071 /// use std::path::Path;
2073 /// let path = Path::new("/foo/bar");
2074 /// let parent = path.parent().unwrap();
2075 /// assert_eq!(parent, Path::new("/foo"));
2077 /// let grand_parent = parent.parent().unwrap();
2078 /// assert_eq!(grand_parent, Path::new("/"));
2079 /// assert_eq!(grand_parent.parent(), None);
2081 #[stable(feature = "rust1", since = "1.0.0")]
2082 pub fn parent(&self) -> Option<&Path> {
2083 let mut comps = self.components();
2084 let comp = comps.next_back();
2085 comp.and_then(|p| match p {
2086 Component::Normal(_) | Component::CurDir | Component::ParentDir => {
2087 Some(comps.as_path())
2093 /// Produces an iterator over `Path` and its ancestors.
2095 /// The iterator will yield the `Path` that is returned if the [`parent`] method is used zero
2096 /// or more times. That means, the iterator will yield `&self`, `&self.parent().unwrap()`,
2097 /// `&self.parent().unwrap().parent().unwrap()` and so on. If the [`parent`] method returns
2098 /// [`None`], the iterator will do likewise. The iterator will always yield at least one value,
2104 /// use std::path::Path;
2106 /// let mut ancestors = Path::new("/foo/bar").ancestors();
2107 /// assert_eq!(ancestors.next(), Some(Path::new("/foo/bar")));
2108 /// assert_eq!(ancestors.next(), Some(Path::new("/foo")));
2109 /// assert_eq!(ancestors.next(), Some(Path::new("/")));
2110 /// assert_eq!(ancestors.next(), None);
2112 /// let mut ancestors = Path::new("../foo/bar").ancestors();
2113 /// assert_eq!(ancestors.next(), Some(Path::new("../foo/bar")));
2114 /// assert_eq!(ancestors.next(), Some(Path::new("../foo")));
2115 /// assert_eq!(ancestors.next(), Some(Path::new("..")));
2116 /// assert_eq!(ancestors.next(), Some(Path::new("")));
2117 /// assert_eq!(ancestors.next(), None);
2120 /// [`parent`]: Path::parent
2121 #[stable(feature = "path_ancestors", since = "1.28.0")]
2123 pub fn ancestors(&self) -> Ancestors<'_> {
2124 Ancestors { next: Some(&self) }
2127 /// Returns the final component of the `Path`, if there is one.
2129 /// If the path is a normal file, this is the file name. If it's the path of a directory, this
2130 /// is the directory name.
2132 /// Returns [`None`] if the path terminates in `..`.
2137 /// use std::path::Path;
2138 /// use std::ffi::OsStr;
2140 /// assert_eq!(Some(OsStr::new("bin")), Path::new("/usr/bin/").file_name());
2141 /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("tmp/foo.txt").file_name());
2142 /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name());
2143 /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name());
2144 /// assert_eq!(None, Path::new("foo.txt/..").file_name());
2145 /// assert_eq!(None, Path::new("/").file_name());
2147 #[stable(feature = "rust1", since = "1.0.0")]
2148 pub fn file_name(&self) -> Option<&OsStr> {
2149 self.components().next_back().and_then(|p| match p {
2150 Component::Normal(p) => Some(p),
2155 /// Returns a path that, when joined onto `base`, yields `self`.
2159 /// If `base` is not a prefix of `self` (i.e., [`starts_with`]
2160 /// returns `false`), returns [`Err`].
2162 /// [`starts_with`]: Path::starts_with
2167 /// use std::path::{Path, PathBuf};
2169 /// let path = Path::new("/test/haha/foo.txt");
2171 /// assert_eq!(path.strip_prefix("/"), Ok(Path::new("test/haha/foo.txt")));
2172 /// assert_eq!(path.strip_prefix("/test"), Ok(Path::new("haha/foo.txt")));
2173 /// assert_eq!(path.strip_prefix("/test/"), Ok(Path::new("haha/foo.txt")));
2174 /// assert_eq!(path.strip_prefix("/test/haha/foo.txt"), Ok(Path::new("")));
2175 /// assert_eq!(path.strip_prefix("/test/haha/foo.txt/"), Ok(Path::new("")));
2177 /// assert!(path.strip_prefix("test").is_err());
2178 /// assert!(path.strip_prefix("/haha").is_err());
2180 /// let prefix = PathBuf::from("/test/");
2181 /// assert_eq!(path.strip_prefix(prefix), Ok(Path::new("haha/foo.txt")));
2183 #[stable(since = "1.7.0", feature = "path_strip_prefix")]
2184 pub fn strip_prefix<P>(&self, base: P) -> Result<&Path, StripPrefixError>
2188 self._strip_prefix(base.as_ref())
2191 fn _strip_prefix(&self, base: &Path) -> Result<&Path, StripPrefixError> {
2192 iter_after(self.components(), base.components())
2193 .map(|c| c.as_path())
2194 .ok_or(StripPrefixError(()))
2197 /// Determines whether `base` is a prefix of `self`.
2199 /// Only considers whole path components to match.
2204 /// use std::path::Path;
2206 /// let path = Path::new("/etc/passwd");
2208 /// assert!(path.starts_with("/etc"));
2209 /// assert!(path.starts_with("/etc/"));
2210 /// assert!(path.starts_with("/etc/passwd"));
2211 /// assert!(path.starts_with("/etc/passwd/")); // extra slash is okay
2212 /// assert!(path.starts_with("/etc/passwd///")); // multiple extra slashes are okay
2214 /// assert!(!path.starts_with("/e"));
2215 /// assert!(!path.starts_with("/etc/passwd.txt"));
2217 /// assert!(!Path::new("/etc/foo.rs").starts_with("/etc/foo"));
2219 #[stable(feature = "rust1", since = "1.0.0")]
2220 pub fn starts_with<P: AsRef<Path>>(&self, base: P) -> bool {
2221 self._starts_with(base.as_ref())
2224 fn _starts_with(&self, base: &Path) -> bool {
2225 iter_after(self.components(), base.components()).is_some()
2228 /// Determines whether `child` is a suffix of `self`.
2230 /// Only considers whole path components to match.
2235 /// use std::path::Path;
2237 /// let path = Path::new("/etc/resolv.conf");
2239 /// assert!(path.ends_with("resolv.conf"));
2240 /// assert!(path.ends_with("etc/resolv.conf"));
2241 /// assert!(path.ends_with("/etc/resolv.conf"));
2243 /// assert!(!path.ends_with("/resolv.conf"));
2244 /// assert!(!path.ends_with("conf")); // use .extension() instead
2246 #[stable(feature = "rust1", since = "1.0.0")]
2247 pub fn ends_with<P: AsRef<Path>>(&self, child: P) -> bool {
2248 self._ends_with(child.as_ref())
2251 fn _ends_with(&self, child: &Path) -> bool {
2252 iter_after(self.components().rev(), child.components().rev()).is_some()
2255 /// Extracts the stem (non-extension) portion of [`self.file_name`].
2257 /// [`self.file_name`]: Path::file_name
2261 /// * [`None`], if there is no file name;
2262 /// * The entire file name if there is no embedded `.`;
2263 /// * The entire file name if the file name begins with `.` and has no other `.`s within;
2264 /// * Otherwise, the portion of the file name before the final `.`
2269 /// use std::path::Path;
2271 /// assert_eq!("foo", Path::new("foo.rs").file_stem().unwrap());
2272 /// assert_eq!("foo.tar", Path::new("foo.tar.gz").file_stem().unwrap());
2276 /// This method is similar to [`Path::file_prefix`], which extracts the portion of the file name
2277 /// before the *first* `.`
2279 /// [`Path::file_prefix`]: Path::file_prefix
2281 #[stable(feature = "rust1", since = "1.0.0")]
2282 pub fn file_stem(&self) -> Option<&OsStr> {
2283 self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.or(after))
2286 /// Extracts the prefix of [`self.file_name`].
2290 /// * [`None`], if there is no file name;
2291 /// * The entire file name if there is no embedded `.`;
2292 /// * The portion of the file name before the first non-beginning `.`;
2293 /// * The entire file name if the file name begins with `.` and has no other `.`s within;
2294 /// * The portion of the file name before the second `.` if the file name begins with `.`
2296 /// [`self.file_name`]: Path::file_name
2301 /// # #![feature(path_file_prefix)]
2302 /// use std::path::Path;
2304 /// assert_eq!("foo", Path::new("foo.rs").file_prefix().unwrap());
2305 /// assert_eq!("foo", Path::new("foo.tar.gz").file_prefix().unwrap());
2309 /// This method is similar to [`Path::file_stem`], which extracts the portion of the file name
2310 /// before the *last* `.`
2312 /// [`Path::file_stem`]: Path::file_stem
2314 #[unstable(feature = "path_file_prefix", issue = "86319")]
2315 pub fn file_prefix(&self) -> Option<&OsStr> {
2316 self.file_name().map(split_file_at_dot).and_then(|(before, _after)| Some(before))
2319 /// Extracts the extension of [`self.file_name`], if possible.
2321 /// The extension is:
2323 /// * [`None`], if there is no file name;
2324 /// * [`None`], if there is no embedded `.`;
2325 /// * [`None`], if the file name begins with `.` and has no other `.`s within;
2326 /// * Otherwise, the portion of the file name after the final `.`
2328 /// [`self.file_name`]: Path::file_name
2333 /// use std::path::Path;
2335 /// assert_eq!("rs", Path::new("foo.rs").extension().unwrap());
2336 /// assert_eq!("gz", Path::new("foo.tar.gz").extension().unwrap());
2338 #[stable(feature = "rust1", since = "1.0.0")]
2339 pub fn extension(&self) -> Option<&OsStr> {
2340 self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.and(after))
2343 /// Creates an owned [`PathBuf`] with `path` adjoined to `self`.
2345 /// See [`PathBuf::push`] for more details on what it means to adjoin a path.
2350 /// use std::path::{Path, PathBuf};
2352 /// assert_eq!(Path::new("/etc").join("passwd"), PathBuf::from("/etc/passwd"));
2354 #[stable(feature = "rust1", since = "1.0.0")]
2356 pub fn join<P: AsRef<Path>>(&self, path: P) -> PathBuf {
2357 self._join(path.as_ref())
2360 fn _join(&self, path: &Path) -> PathBuf {
2361 let mut buf = self.to_path_buf();
2366 /// Creates an owned [`PathBuf`] like `self` but with the given file name.
2368 /// See [`PathBuf::set_file_name`] for more details.
2373 /// use std::path::{Path, PathBuf};
2375 /// let path = Path::new("/tmp/foo.txt");
2376 /// assert_eq!(path.with_file_name("bar.txt"), PathBuf::from("/tmp/bar.txt"));
2378 /// let path = Path::new("/tmp");
2379 /// assert_eq!(path.with_file_name("var"), PathBuf::from("/var"));
2381 #[stable(feature = "rust1", since = "1.0.0")]
2382 pub fn with_file_name<S: AsRef<OsStr>>(&self, file_name: S) -> PathBuf {
2383 self._with_file_name(file_name.as_ref())
2386 fn _with_file_name(&self, file_name: &OsStr) -> PathBuf {
2387 let mut buf = self.to_path_buf();
2388 buf.set_file_name(file_name);
2392 /// Creates an owned [`PathBuf`] like `self` but with the given extension.
2394 /// See [`PathBuf::set_extension`] for more details.
2399 /// use std::path::{Path, PathBuf};
2401 /// let path = Path::new("foo.rs");
2402 /// assert_eq!(path.with_extension("txt"), PathBuf::from("foo.txt"));
2404 /// let path = Path::new("foo.tar.gz");
2405 /// assert_eq!(path.with_extension(""), PathBuf::from("foo.tar"));
2406 /// assert_eq!(path.with_extension("xz"), PathBuf::from("foo.tar.xz"));
2407 /// assert_eq!(path.with_extension("").with_extension("txt"), PathBuf::from("foo.txt"));
2409 #[stable(feature = "rust1", since = "1.0.0")]
2410 pub fn with_extension<S: AsRef<OsStr>>(&self, extension: S) -> PathBuf {
2411 self._with_extension(extension.as_ref())
2414 fn _with_extension(&self, extension: &OsStr) -> PathBuf {
2415 let mut buf = self.to_path_buf();
2416 buf.set_extension(extension);
2420 /// Produces an iterator over the [`Component`]s of the path.
2422 /// When parsing the path, there is a small amount of normalization:
2424 /// * Repeated separators are ignored, so `a/b` and `a//b` both have
2425 /// `a` and `b` as components.
2427 /// * Occurrences of `.` are normalized away, except if they are at the
2428 /// beginning of the path. For example, `a/./b`, `a/b/`, `a/b/.` and
2429 /// `a/b` all have `a` and `b` as components, but `./a/b` starts with
2430 /// an additional [`CurDir`] component.
2432 /// * A trailing slash is normalized away, `/a/b` and `/a/b/` are equivalent.
2434 /// Note that no other normalization takes place; in particular, `a/c`
2435 /// and `a/b/../c` are distinct, to account for the possibility that `b`
2436 /// is a symbolic link (so its parent isn't `a`).
2441 /// use std::path::{Path, Component};
2442 /// use std::ffi::OsStr;
2444 /// let mut components = Path::new("/tmp/foo.txt").components();
2446 /// assert_eq!(components.next(), Some(Component::RootDir));
2447 /// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("tmp"))));
2448 /// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("foo.txt"))));
2449 /// assert_eq!(components.next(), None)
2452 /// [`CurDir`]: Component::CurDir
2453 #[stable(feature = "rust1", since = "1.0.0")]
2454 pub fn components(&self) -> Components<'_> {
2455 let prefix = parse_prefix(self.as_os_str());
2457 path: self.as_u8_slice(),
2459 has_physical_root: has_physical_root(self.as_u8_slice(), prefix)
2460 || has_redox_scheme(self.as_u8_slice()),
2461 front: State::Prefix,
2466 /// Produces an iterator over the path's components viewed as [`OsStr`]
2469 /// For more information about the particulars of how the path is separated
2470 /// into components, see [`components`].
2472 /// [`components`]: Path::components
2477 /// use std::path::{self, Path};
2478 /// use std::ffi::OsStr;
2480 /// let mut it = Path::new("/tmp/foo.txt").iter();
2481 /// assert_eq!(it.next(), Some(OsStr::new(&path::MAIN_SEPARATOR.to_string())));
2482 /// assert_eq!(it.next(), Some(OsStr::new("tmp")));
2483 /// assert_eq!(it.next(), Some(OsStr::new("foo.txt")));
2484 /// assert_eq!(it.next(), None)
2486 #[stable(feature = "rust1", since = "1.0.0")]
2488 pub fn iter(&self) -> Iter<'_> {
2489 Iter { inner: self.components() }
2492 /// Returns an object that implements [`Display`] for safely printing paths
2493 /// that may contain non-Unicode data. This may perform lossy conversion,
2494 /// depending on the platform. If you would like an implementation which
2495 /// escapes the path please use [`Debug`] instead.
2497 /// [`Display`]: fmt::Display
2502 /// use std::path::Path;
2504 /// let path = Path::new("/tmp/foo.rs");
2506 /// println!("{}", path.display());
2508 #[stable(feature = "rust1", since = "1.0.0")]
2510 pub fn display(&self) -> Display<'_> {
2511 Display { path: self }
2514 /// Queries the file system to get information about a file, directory, etc.
2516 /// This function will traverse symbolic links to query information about the
2517 /// destination file.
2519 /// This is an alias to [`fs::metadata`].
2524 /// use std::path::Path;
2526 /// let path = Path::new("/Minas/tirith");
2527 /// let metadata = path.metadata().expect("metadata call failed");
2528 /// println!("{:?}", metadata.file_type());
2530 #[stable(feature = "path_ext", since = "1.5.0")]
2532 pub fn metadata(&self) -> io::Result<fs::Metadata> {
2536 /// Queries the metadata about a file without following symlinks.
2538 /// This is an alias to [`fs::symlink_metadata`].
2543 /// use std::path::Path;
2545 /// let path = Path::new("/Minas/tirith");
2546 /// let metadata = path.symlink_metadata().expect("symlink_metadata call failed");
2547 /// println!("{:?}", metadata.file_type());
2549 #[stable(feature = "path_ext", since = "1.5.0")]
2551 pub fn symlink_metadata(&self) -> io::Result<fs::Metadata> {
2552 fs::symlink_metadata(self)
2555 /// Returns the canonical, absolute form of the path with all intermediate
2556 /// components normalized and symbolic links resolved.
2558 /// This is an alias to [`fs::canonicalize`].
2563 /// use std::path::{Path, PathBuf};
2565 /// let path = Path::new("/foo/test/../test/bar.rs");
2566 /// assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs"));
2568 #[stable(feature = "path_ext", since = "1.5.0")]
2570 pub fn canonicalize(&self) -> io::Result<PathBuf> {
2571 fs::canonicalize(self)
2574 /// Reads a symbolic link, returning the file that the link points to.
2576 /// This is an alias to [`fs::read_link`].
2581 /// use std::path::Path;
2583 /// let path = Path::new("/laputa/sky_castle.rs");
2584 /// let path_link = path.read_link().expect("read_link call failed");
2586 #[stable(feature = "path_ext", since = "1.5.0")]
2588 pub fn read_link(&self) -> io::Result<PathBuf> {
2592 /// Returns an iterator over the entries within a directory.
2594 /// The iterator will yield instances of <code>[io::Result]<[fs::DirEntry]></code>. New
2595 /// errors may be encountered after an iterator is initially constructed.
2597 /// This is an alias to [`fs::read_dir`].
2602 /// use std::path::Path;
2604 /// let path = Path::new("/laputa");
2605 /// for entry in path.read_dir().expect("read_dir call failed") {
2606 /// if let Ok(entry) = entry {
2607 /// println!("{:?}", entry.path());
2611 #[stable(feature = "path_ext", since = "1.5.0")]
2613 pub fn read_dir(&self) -> io::Result<fs::ReadDir> {
2617 /// Returns `true` if the path points at an existing entity.
2619 /// This function will traverse symbolic links to query information about the
2620 /// destination file.
2622 /// If you cannot access the metadata of the file, e.g. because of a
2623 /// permission error or broken symbolic links, this will return `false`.
2628 /// use std::path::Path;
2629 /// assert!(!Path::new("does_not_exist.txt").exists());
2634 /// This is a convenience function that coerces errors to false. If you want to
2635 /// check errors, call [`fs::metadata`].
2636 #[stable(feature = "path_ext", since = "1.5.0")]
2638 pub fn exists(&self) -> bool {
2639 fs::metadata(self).is_ok()
2642 /// Returns `Ok(true)` if the path points at an existing entity.
2644 /// This function will traverse symbolic links to query information about the
2645 /// destination file. In case of broken symbolic links this will return `Ok(false)`.
2647 /// As opposed to the `exists()` method, this one doesn't silently ignore errors
2648 /// unrelated to the path not existing. (E.g. it will return `Err(_)` in case of permission
2649 /// denied on some of the parent directories.)
2654 /// #![feature(path_try_exists)]
2656 /// use std::path::Path;
2657 /// assert!(!Path::new("does_not_exist.txt").try_exists().expect("Can't check existence of file does_not_exist.txt"));
2658 /// assert!(Path::new("/root/secret_file.txt").try_exists().is_err());
2660 // FIXME: stabilization should modify documentation of `exists()` to recommend this method
2662 #[unstable(feature = "path_try_exists", issue = "83186")]
2664 pub fn try_exists(&self) -> io::Result<bool> {
2665 fs::try_exists(self)
2668 /// Returns `true` if the path exists on disk and is pointing at a regular file.
2670 /// This function will traverse symbolic links to query information about the
2671 /// destination file.
2673 /// If you cannot access the metadata of the file, e.g. because of a
2674 /// permission error or broken symbolic links, this will return `false`.
2679 /// use std::path::Path;
2680 /// assert_eq!(Path::new("./is_a_directory/").is_file(), false);
2681 /// assert_eq!(Path::new("a_file.txt").is_file(), true);
2686 /// This is a convenience function that coerces errors to false. If you want to
2687 /// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call
2688 /// [`fs::Metadata::is_file`] if it was [`Ok`].
2690 /// When the goal is simply to read from (or write to) the source, the most
2691 /// reliable way to test the source can be read (or written to) is to open
2692 /// it. Only using `is_file` can break workflows like `diff <( prog_a )` on
2693 /// a Unix-like system for example. See [`fs::File::open`] or
2694 /// [`fs::OpenOptions::open`] for more information.
2695 #[stable(feature = "path_ext", since = "1.5.0")]
2696 pub fn is_file(&self) -> bool {
2697 fs::metadata(self).map(|m| m.is_file()).unwrap_or(false)
2700 /// Returns `true` if the path exists on disk and is pointing at a directory.
2702 /// This function will traverse symbolic links to query information about the
2703 /// destination file.
2705 /// If you cannot access the metadata of the file, e.g. because of a
2706 /// permission error or broken symbolic links, this will return `false`.
2711 /// use std::path::Path;
2712 /// assert_eq!(Path::new("./is_a_directory/").is_dir(), true);
2713 /// assert_eq!(Path::new("a_file.txt").is_dir(), false);
2718 /// This is a convenience function that coerces errors to false. If you want to
2719 /// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call
2720 /// [`fs::Metadata::is_dir`] if it was [`Ok`].
2721 #[stable(feature = "path_ext", since = "1.5.0")]
2722 pub fn is_dir(&self) -> bool {
2723 fs::metadata(self).map(|m| m.is_dir()).unwrap_or(false)
2726 /// Returns true if the path exists on disk and is pointing at a symbolic link.
2728 /// This function will not traverse symbolic links.
2729 /// In case of a broken symbolic link this will also return true.
2731 /// If you cannot access the directory containing the file, e.g., because of a
2732 /// permission error, this will return false.
2736 #[cfg_attr(unix, doc = "```no_run")]
2737 #[cfg_attr(not(unix), doc = "```ignore")]
2738 /// #![feature(is_symlink)]
2739 /// use std::path::Path;
2740 /// use std::os::unix::fs::symlink;
2742 /// let link_path = Path::new("link");
2743 /// symlink("/origin_does_not_exists/", link_path).unwrap();
2744 /// assert_eq!(link_path.is_symlink(), true);
2745 /// assert_eq!(link_path.exists(), false);
2747 #[unstable(feature = "is_symlink", issue = "85748")]
2748 pub fn is_symlink(&self) -> bool {
2749 fs::symlink_metadata(self).map(|m| m.is_symlink()).unwrap_or(false)
2752 /// Converts a [`Box<Path>`](Box) into a [`PathBuf`] without copying or
2754 #[stable(feature = "into_boxed_path", since = "1.20.0")]
2755 pub fn into_path_buf(self: Box<Path>) -> PathBuf {
2756 let rw = Box::into_raw(self) as *mut OsStr;
2757 let inner = unsafe { Box::from_raw(rw) };
2758 PathBuf { inner: OsString::from(inner) }
2762 #[stable(feature = "rust1", since = "1.0.0")]
2763 impl AsRef<OsStr> for Path {
2765 fn as_ref(&self) -> &OsStr {
2770 #[stable(feature = "rust1", since = "1.0.0")]
2771 impl fmt::Debug for Path {
2772 fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
2773 fmt::Debug::fmt(&self.inner, formatter)
2777 /// Helper struct for safely printing paths with [`format!`] and `{}`.
2779 /// A [`Path`] might contain non-Unicode data. This `struct` implements the
2780 /// [`Display`] trait in a way that mitigates that. It is created by the
2781 /// [`display`](Path::display) method on [`Path`]. This may perform lossy
2782 /// conversion, depending on the platform. If you would like an implementation
2783 /// which escapes the path please use [`Debug`] instead.
2788 /// use std::path::Path;
2790 /// let path = Path::new("/tmp/foo.rs");
2792 /// println!("{}", path.display());
2795 /// [`Display`]: fmt::Display
2796 /// [`format!`]: crate::format
2797 #[stable(feature = "rust1", since = "1.0.0")]
2798 pub struct Display<'a> {
2802 #[stable(feature = "rust1", since = "1.0.0")]
2803 impl fmt::Debug for Display<'_> {
2804 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2805 fmt::Debug::fmt(&self.path, f)
2809 #[stable(feature = "rust1", since = "1.0.0")]
2810 impl fmt::Display for Display<'_> {
2811 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2812 self.path.inner.display(f)
2816 #[stable(feature = "rust1", since = "1.0.0")]
2817 impl cmp::PartialEq for Path {
2819 fn eq(&self, other: &Path) -> bool {
2820 self.components() == other.components()
2824 #[stable(feature = "rust1", since = "1.0.0")]
2825 impl Hash for Path {
2826 fn hash<H: Hasher>(&self, h: &mut H) {
2827 for component in self.components() {
2833 #[stable(feature = "rust1", since = "1.0.0")]
2834 impl cmp::Eq for Path {}
2836 #[stable(feature = "rust1", since = "1.0.0")]
2837 impl cmp::PartialOrd for Path {
2839 fn partial_cmp(&self, other: &Path) -> Option<cmp::Ordering> {
2840 Some(compare_components(self.components(), other.components()))
2844 #[stable(feature = "rust1", since = "1.0.0")]
2845 impl cmp::Ord for Path {
2847 fn cmp(&self, other: &Path) -> cmp::Ordering {
2848 compare_components(self.components(), other.components())
2852 #[stable(feature = "rust1", since = "1.0.0")]
2853 impl AsRef<Path> for Path {
2855 fn as_ref(&self) -> &Path {
2860 #[stable(feature = "rust1", since = "1.0.0")]
2861 impl AsRef<Path> for OsStr {
2863 fn as_ref(&self) -> &Path {
2868 #[stable(feature = "cow_os_str_as_ref_path", since = "1.8.0")]
2869 impl AsRef<Path> for Cow<'_, OsStr> {
2871 fn as_ref(&self) -> &Path {
2876 #[stable(feature = "rust1", since = "1.0.0")]
2877 impl AsRef<Path> for OsString {
2879 fn as_ref(&self) -> &Path {
2884 #[stable(feature = "rust1", since = "1.0.0")]
2885 impl AsRef<Path> for str {
2887 fn as_ref(&self) -> &Path {
2892 #[stable(feature = "rust1", since = "1.0.0")]
2893 impl AsRef<Path> for String {
2895 fn as_ref(&self) -> &Path {
2900 #[stable(feature = "rust1", since = "1.0.0")]
2901 impl AsRef<Path> for PathBuf {
2903 fn as_ref(&self) -> &Path {
2908 #[stable(feature = "path_into_iter", since = "1.6.0")]
2909 impl<'a> IntoIterator for &'a PathBuf {
2910 type Item = &'a OsStr;
2911 type IntoIter = Iter<'a>;
2913 fn into_iter(self) -> Iter<'a> {
2918 #[stable(feature = "path_into_iter", since = "1.6.0")]
2919 impl<'a> IntoIterator for &'a Path {
2920 type Item = &'a OsStr;
2921 type IntoIter = Iter<'a>;
2923 fn into_iter(self) -> Iter<'a> {
2928 macro_rules! impl_cmp {
2929 ($lhs:ty, $rhs: ty) => {
2930 #[stable(feature = "partialeq_path", since = "1.6.0")]
2931 impl<'a, 'b> PartialEq<$rhs> for $lhs {
2933 fn eq(&self, other: &$rhs) -> bool {
2934 <Path as PartialEq>::eq(self, other)
2938 #[stable(feature = "partialeq_path", since = "1.6.0")]
2939 impl<'a, 'b> PartialEq<$lhs> for $rhs {
2941 fn eq(&self, other: &$lhs) -> bool {
2942 <Path as PartialEq>::eq(self, other)
2946 #[stable(feature = "cmp_path", since = "1.8.0")]
2947 impl<'a, 'b> PartialOrd<$rhs> for $lhs {
2949 fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
2950 <Path as PartialOrd>::partial_cmp(self, other)
2954 #[stable(feature = "cmp_path", since = "1.8.0")]
2955 impl<'a, 'b> PartialOrd<$lhs> for $rhs {
2957 fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
2958 <Path as PartialOrd>::partial_cmp(self, other)
2964 impl_cmp!(PathBuf, Path);
2965 impl_cmp!(PathBuf, &'a Path);
2966 impl_cmp!(Cow<'a, Path>, Path);
2967 impl_cmp!(Cow<'a, Path>, &'b Path);
2968 impl_cmp!(Cow<'a, Path>, PathBuf);
2970 macro_rules! impl_cmp_os_str {
2971 ($lhs:ty, $rhs: ty) => {
2972 #[stable(feature = "cmp_path", since = "1.8.0")]
2973 impl<'a, 'b> PartialEq<$rhs> for $lhs {
2975 fn eq(&self, other: &$rhs) -> bool {
2976 <Path as PartialEq>::eq(self, other.as_ref())
2980 #[stable(feature = "cmp_path", since = "1.8.0")]
2981 impl<'a, 'b> PartialEq<$lhs> for $rhs {
2983 fn eq(&self, other: &$lhs) -> bool {
2984 <Path as PartialEq>::eq(self.as_ref(), other)
2988 #[stable(feature = "cmp_path", since = "1.8.0")]
2989 impl<'a, 'b> PartialOrd<$rhs> for $lhs {
2991 fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
2992 <Path as PartialOrd>::partial_cmp(self, other.as_ref())
2996 #[stable(feature = "cmp_path", since = "1.8.0")]
2997 impl<'a, 'b> PartialOrd<$lhs> for $rhs {
2999 fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
3000 <Path as PartialOrd>::partial_cmp(self.as_ref(), other)
3006 impl_cmp_os_str!(PathBuf, OsStr);
3007 impl_cmp_os_str!(PathBuf, &'a OsStr);
3008 impl_cmp_os_str!(PathBuf, Cow<'a, OsStr>);
3009 impl_cmp_os_str!(PathBuf, OsString);
3010 impl_cmp_os_str!(Path, OsStr);
3011 impl_cmp_os_str!(Path, &'a OsStr);
3012 impl_cmp_os_str!(Path, Cow<'a, OsStr>);
3013 impl_cmp_os_str!(Path, OsString);
3014 impl_cmp_os_str!(&'a Path, OsStr);
3015 impl_cmp_os_str!(&'a Path, Cow<'b, OsStr>);
3016 impl_cmp_os_str!(&'a Path, OsString);
3017 impl_cmp_os_str!(Cow<'a, Path>, OsStr);
3018 impl_cmp_os_str!(Cow<'a, Path>, &'b OsStr);
3019 impl_cmp_os_str!(Cow<'a, Path>, OsString);
3021 #[stable(since = "1.7.0", feature = "strip_prefix")]
3022 impl fmt::Display for StripPrefixError {
3023 #[allow(deprecated, deprecated_in_future)]
3024 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
3025 self.description().fmt(f)
3029 #[stable(since = "1.7.0", feature = "strip_prefix")]
3030 impl Error for StripPrefixError {
3031 #[allow(deprecated)]
3032 fn description(&self) -> &str {