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 #[must_use = "`self` will be dropped if the result is not used"]
536 #[stable(feature = "rust1", since = "1.0.0")]
537 pub fn as_os_str(self) -> &'a OsStr {
539 Component::Prefix(p) => p.as_os_str(),
540 Component::RootDir => OsStr::new(MAIN_SEP_STR),
541 Component::CurDir => OsStr::new("."),
542 Component::ParentDir => OsStr::new(".."),
543 Component::Normal(path) => path,
548 #[stable(feature = "rust1", since = "1.0.0")]
549 impl AsRef<OsStr> for Component<'_> {
551 fn as_ref(&self) -> &OsStr {
556 #[stable(feature = "path_component_asref", since = "1.25.0")]
557 impl AsRef<Path> for Component<'_> {
559 fn as_ref(&self) -> &Path {
560 self.as_os_str().as_ref()
564 /// An iterator over the [`Component`]s of a [`Path`].
566 /// This `struct` is created by the [`components`] method on [`Path`].
567 /// See its documentation for more.
572 /// use std::path::Path;
574 /// let path = Path::new("/tmp/foo/bar.txt");
576 /// for component in path.components() {
577 /// println!("{:?}", component);
581 /// [`components`]: Path::components
583 #[stable(feature = "rust1", since = "1.0.0")]
584 pub struct Components<'a> {
585 // The path left to parse components from
588 // The prefix as it was originally parsed, if any
589 prefix: Option<Prefix<'a>>,
591 // true if path *physically* has a root separator; for most Windows
592 // prefixes, it may have a "logical" root separator for the purposes of
593 // normalization, e.g., \\server\share == \\server\share\.
594 has_physical_root: bool,
596 // The iterator is double-ended, and these two states keep track of what has
597 // been produced from either end
602 /// An iterator over the [`Component`]s of a [`Path`], as [`OsStr`] slices.
604 /// This `struct` is created by the [`iter`] method on [`Path`].
605 /// See its documentation for more.
607 /// [`iter`]: Path::iter
609 #[stable(feature = "rust1", since = "1.0.0")]
610 pub struct Iter<'a> {
611 inner: Components<'a>,
614 #[stable(feature = "path_components_debug", since = "1.13.0")]
615 impl fmt::Debug for Components<'_> {
616 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
617 struct DebugHelper<'a>(&'a Path);
619 impl fmt::Debug for DebugHelper<'_> {
620 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
621 f.debug_list().entries(self.0.components()).finish()
625 f.debug_tuple("Components").field(&DebugHelper(self.as_path())).finish()
629 impl<'a> Components<'a> {
630 // how long is the prefix, if any?
632 fn prefix_len(&self) -> usize {
633 self.prefix.as_ref().map(Prefix::len).unwrap_or(0)
637 fn prefix_verbatim(&self) -> bool {
638 self.prefix.as_ref().map(Prefix::is_verbatim).unwrap_or(false)
641 /// how much of the prefix is left from the point of view of iteration?
643 fn prefix_remaining(&self) -> usize {
644 if self.front == State::Prefix { self.prefix_len() } else { 0 }
647 // Given the iteration so far, how much of the pre-State::Body path is left?
649 fn len_before_body(&self) -> usize {
650 let root = if self.front <= State::StartDir && self.has_physical_root { 1 } else { 0 };
651 let cur_dir = if self.front <= State::StartDir && self.include_cur_dir() { 1 } else { 0 };
652 self.prefix_remaining() + root + cur_dir
655 // is the iteration complete?
657 fn finished(&self) -> bool {
658 self.front == State::Done || self.back == State::Done || self.front > self.back
662 fn is_sep_byte(&self, b: u8) -> bool {
663 if self.prefix_verbatim() { is_verbatim_sep(b) } else { is_sep_byte(b) }
666 /// Extracts a slice corresponding to the portion of the path remaining for iteration.
671 /// use std::path::Path;
673 /// let mut components = Path::new("/tmp/foo/bar.txt").components();
674 /// components.next();
675 /// components.next();
677 /// assert_eq!(Path::new("foo/bar.txt"), components.as_path());
679 #[stable(feature = "rust1", since = "1.0.0")]
680 pub fn as_path(&self) -> &'a Path {
681 let mut comps = self.clone();
682 if comps.front == State::Body {
685 if comps.back == State::Body {
688 unsafe { Path::from_u8_slice(comps.path) }
691 /// Is the *original* path rooted?
692 fn has_root(&self) -> bool {
693 if self.has_physical_root {
696 if let Some(p) = self.prefix {
697 if p.has_implicit_root() {
704 /// Should the normalized path include a leading . ?
705 fn include_cur_dir(&self) -> bool {
709 let mut iter = self.path[self.prefix_len()..].iter();
710 match (iter.next(), iter.next()) {
711 (Some(&b'.'), None) => true,
712 (Some(&b'.'), Some(&b)) => self.is_sep_byte(b),
717 // parse a given byte sequence into the corresponding path component
718 fn parse_single_component<'b>(&self, comp: &'b [u8]) -> Option<Component<'b>> {
720 b"." if self.prefix_verbatim() => Some(Component::CurDir),
721 b"." => None, // . components are normalized away, except at
722 // the beginning of a path, which is treated
723 // separately via `include_cur_dir`
724 b".." => Some(Component::ParentDir),
726 _ => Some(Component::Normal(unsafe { u8_slice_as_os_str(comp) })),
730 // parse a component from the left, saying how many bytes to consume to
731 // remove the component
732 fn parse_next_component(&self) -> (usize, Option<Component<'a>>) {
733 debug_assert!(self.front == State::Body);
734 let (extra, comp) = match self.path.iter().position(|b| self.is_sep_byte(*b)) {
735 None => (0, self.path),
736 Some(i) => (1, &self.path[..i]),
738 (comp.len() + extra, self.parse_single_component(comp))
741 // parse a component from the right, saying how many bytes to consume to
742 // remove the component
743 fn parse_next_component_back(&self) -> (usize, Option<Component<'a>>) {
744 debug_assert!(self.back == State::Body);
745 let start = self.len_before_body();
746 let (extra, comp) = match self.path[start..].iter().rposition(|b| self.is_sep_byte(*b)) {
747 None => (0, &self.path[start..]),
748 Some(i) => (1, &self.path[start + i + 1..]),
750 (comp.len() + extra, self.parse_single_component(comp))
753 // trim away repeated separators (i.e., empty components) on the left
754 fn trim_left(&mut self) {
755 while !self.path.is_empty() {
756 let (size, comp) = self.parse_next_component();
760 self.path = &self.path[size..];
765 // trim away repeated separators (i.e., empty components) on the right
766 fn trim_right(&mut self) {
767 while self.path.len() > self.len_before_body() {
768 let (size, comp) = self.parse_next_component_back();
772 self.path = &self.path[..self.path.len() - size];
778 #[stable(feature = "rust1", since = "1.0.0")]
779 impl AsRef<Path> for Components<'_> {
781 fn as_ref(&self) -> &Path {
786 #[stable(feature = "rust1", since = "1.0.0")]
787 impl AsRef<OsStr> for Components<'_> {
789 fn as_ref(&self) -> &OsStr {
790 self.as_path().as_os_str()
794 #[stable(feature = "path_iter_debug", since = "1.13.0")]
795 impl fmt::Debug for Iter<'_> {
796 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
797 struct DebugHelper<'a>(&'a Path);
799 impl fmt::Debug for DebugHelper<'_> {
800 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
801 f.debug_list().entries(self.0.iter()).finish()
805 f.debug_tuple("Iter").field(&DebugHelper(self.as_path())).finish()
810 /// Extracts a slice corresponding to the portion of the path remaining for iteration.
815 /// use std::path::Path;
817 /// let mut iter = Path::new("/tmp/foo/bar.txt").iter();
821 /// assert_eq!(Path::new("foo/bar.txt"), iter.as_path());
823 #[stable(feature = "rust1", since = "1.0.0")]
825 pub fn as_path(&self) -> &'a Path {
830 #[stable(feature = "rust1", since = "1.0.0")]
831 impl AsRef<Path> for Iter<'_> {
833 fn as_ref(&self) -> &Path {
838 #[stable(feature = "rust1", since = "1.0.0")]
839 impl AsRef<OsStr> for Iter<'_> {
841 fn as_ref(&self) -> &OsStr {
842 self.as_path().as_os_str()
846 #[stable(feature = "rust1", since = "1.0.0")]
847 impl<'a> Iterator for Iter<'a> {
848 type Item = &'a OsStr;
851 fn next(&mut self) -> Option<&'a OsStr> {
852 self.inner.next().map(Component::as_os_str)
856 #[stable(feature = "rust1", since = "1.0.0")]
857 impl<'a> DoubleEndedIterator for Iter<'a> {
859 fn next_back(&mut self) -> Option<&'a OsStr> {
860 self.inner.next_back().map(Component::as_os_str)
864 #[stable(feature = "fused", since = "1.26.0")]
865 impl FusedIterator for Iter<'_> {}
867 #[stable(feature = "rust1", since = "1.0.0")]
868 impl<'a> Iterator for Components<'a> {
869 type Item = Component<'a>;
871 fn next(&mut self) -> Option<Component<'a>> {
872 while !self.finished() {
874 State::Prefix if self.prefix_len() > 0 => {
875 self.front = State::StartDir;
876 debug_assert!(self.prefix_len() <= self.path.len());
877 let raw = &self.path[..self.prefix_len()];
878 self.path = &self.path[self.prefix_len()..];
879 return Some(Component::Prefix(PrefixComponent {
880 raw: unsafe { u8_slice_as_os_str(raw) },
881 parsed: self.prefix.unwrap(),
885 self.front = State::StartDir;
888 self.front = State::Body;
889 if self.has_physical_root {
890 debug_assert!(!self.path.is_empty());
891 self.path = &self.path[1..];
892 return Some(Component::RootDir);
893 } else if let Some(p) = self.prefix {
894 if p.has_implicit_root() && !p.is_verbatim() {
895 return Some(Component::RootDir);
897 } else if self.include_cur_dir() {
898 debug_assert!(!self.path.is_empty());
899 self.path = &self.path[1..];
900 return Some(Component::CurDir);
903 State::Body if !self.path.is_empty() => {
904 let (size, comp) = self.parse_next_component();
905 self.path = &self.path[size..];
911 self.front = State::Done;
913 State::Done => unreachable!(),
920 #[stable(feature = "rust1", since = "1.0.0")]
921 impl<'a> DoubleEndedIterator for Components<'a> {
922 fn next_back(&mut self) -> Option<Component<'a>> {
923 while !self.finished() {
925 State::Body if self.path.len() > self.len_before_body() => {
926 let (size, comp) = self.parse_next_component_back();
927 self.path = &self.path[..self.path.len() - size];
933 self.back = State::StartDir;
936 self.back = State::Prefix;
937 if self.has_physical_root {
938 self.path = &self.path[..self.path.len() - 1];
939 return Some(Component::RootDir);
940 } else if let Some(p) = self.prefix {
941 if p.has_implicit_root() && !p.is_verbatim() {
942 return Some(Component::RootDir);
944 } else if self.include_cur_dir() {
945 self.path = &self.path[..self.path.len() - 1];
946 return Some(Component::CurDir);
949 State::Prefix if self.prefix_len() > 0 => {
950 self.back = State::Done;
951 return Some(Component::Prefix(PrefixComponent {
952 raw: unsafe { u8_slice_as_os_str(self.path) },
953 parsed: self.prefix.unwrap(),
957 self.back = State::Done;
960 State::Done => unreachable!(),
967 #[stable(feature = "fused", since = "1.26.0")]
968 impl FusedIterator for Components<'_> {}
970 #[stable(feature = "rust1", since = "1.0.0")]
971 impl<'a> cmp::PartialEq for Components<'a> {
973 fn eq(&self, other: &Components<'a>) -> bool {
974 Iterator::eq(self.clone().rev(), other.clone().rev())
978 #[stable(feature = "rust1", since = "1.0.0")]
979 impl cmp::Eq for Components<'_> {}
981 #[stable(feature = "rust1", since = "1.0.0")]
982 impl<'a> cmp::PartialOrd for Components<'a> {
984 fn partial_cmp(&self, other: &Components<'a>) -> Option<cmp::Ordering> {
985 Some(compare_components(self.clone(), other.clone()))
989 #[stable(feature = "rust1", since = "1.0.0")]
990 impl cmp::Ord for Components<'_> {
992 fn cmp(&self, other: &Self) -> cmp::Ordering {
993 compare_components(self.clone(), other.clone())
997 fn compare_components(mut left: Components<'_>, mut right: Components<'_>) -> cmp::Ordering {
998 // Fast path for long shared prefixes
1000 // - compare raw bytes to find first mismatch
1001 // - backtrack to find separator before mismatch to avoid ambiguous parsings of '.' or '..' characters
1002 // - if found update state to only do a component-wise comparison on the remainder,
1003 // otherwise do it on the full path
1005 // The fast path isn't taken for paths with a PrefixComponent to avoid backtracking into
1006 // the middle of one
1007 if left.prefix.is_none() && right.prefix.is_none() && left.front == right.front {
1008 // this might benefit from a [u8]::first_mismatch simd implementation, if it existed
1009 let first_difference =
1010 match left.path.iter().zip(right.path.iter()).position(|(&a, &b)| a != b) {
1011 None if left.path.len() == right.path.len() => return cmp::Ordering::Equal,
1012 None => left.path.len().min(right.path.len()),
1016 if let Some(previous_sep) =
1017 left.path[..first_difference].iter().rposition(|&b| left.is_sep_byte(b))
1019 let mismatched_component_start = previous_sep + 1;
1020 left.path = &left.path[mismatched_component_start..];
1021 left.front = State::Body;
1022 right.path = &right.path[mismatched_component_start..];
1023 right.front = State::Body;
1027 Iterator::cmp(left, right)
1030 /// An iterator over [`Path`] and its ancestors.
1032 /// This `struct` is created by the [`ancestors`] method on [`Path`].
1033 /// See its documentation for more.
1038 /// use std::path::Path;
1040 /// let path = Path::new("/foo/bar");
1042 /// for ancestor in path.ancestors() {
1043 /// println!("{}", ancestor.display());
1047 /// [`ancestors`]: Path::ancestors
1048 #[derive(Copy, Clone, Debug)]
1049 #[stable(feature = "path_ancestors", since = "1.28.0")]
1050 pub struct Ancestors<'a> {
1051 next: Option<&'a Path>,
1054 #[stable(feature = "path_ancestors", since = "1.28.0")]
1055 impl<'a> Iterator for Ancestors<'a> {
1056 type Item = &'a Path;
1059 fn next(&mut self) -> Option<Self::Item> {
1060 let next = self.next;
1061 self.next = next.and_then(Path::parent);
1066 #[stable(feature = "path_ancestors", since = "1.28.0")]
1067 impl FusedIterator for Ancestors<'_> {}
1069 ////////////////////////////////////////////////////////////////////////////////
1070 // Basic types and traits
1071 ////////////////////////////////////////////////////////////////////////////////
1073 /// An owned, mutable path (akin to [`String`]).
1075 /// This type provides methods like [`push`] and [`set_extension`] that mutate
1076 /// the path in place. It also implements [`Deref`] to [`Path`], meaning that
1077 /// all methods on [`Path`] slices are available on `PathBuf` values as well.
1079 /// [`push`]: PathBuf::push
1080 /// [`set_extension`]: PathBuf::set_extension
1082 /// More details about the overall approach can be found in
1083 /// the [module documentation](self).
1087 /// You can use [`push`] to build up a `PathBuf` from
1091 /// use std::path::PathBuf;
1093 /// let mut path = PathBuf::new();
1095 /// path.push(r"C:\");
1096 /// path.push("windows");
1097 /// path.push("system32");
1099 /// path.set_extension("dll");
1102 /// However, [`push`] is best used for dynamic situations. This is a better way
1103 /// to do this when you know all of the components ahead of time:
1106 /// use std::path::PathBuf;
1108 /// let path: PathBuf = [r"C:\", "windows", "system32.dll"].iter().collect();
1111 /// We can still do better than this! Since these are all strings, we can use
1115 /// use std::path::PathBuf;
1117 /// let path = PathBuf::from(r"C:\windows\system32.dll");
1120 /// Which method works best depends on what kind of situation you're in.
1121 #[cfg_attr(not(test), rustc_diagnostic_item = "PathBuf")]
1122 #[stable(feature = "rust1", since = "1.0.0")]
1124 // `PathBuf::as_mut_vec` current implementation relies
1125 // on `PathBuf` being layout-compatible with `Vec<u8>`.
1126 // When attribute privacy is implemented, `PathBuf` should be annotated as `#[repr(transparent)]`.
1127 // Anyway, `PathBuf` representation and layout are considered implementation detail, are
1128 // not documented and must not be relied upon.
1129 pub struct PathBuf {
1135 fn as_mut_vec(&mut self) -> &mut Vec<u8> {
1136 unsafe { &mut *(self as *mut PathBuf as *mut Vec<u8>) }
1139 /// Allocates an empty `PathBuf`.
1144 /// use std::path::PathBuf;
1146 /// let path = PathBuf::new();
1148 #[stable(feature = "rust1", since = "1.0.0")]
1150 pub fn new() -> PathBuf {
1151 PathBuf { inner: OsString::new() }
1154 /// Creates a new `PathBuf` with a given capacity used to create the
1155 /// internal [`OsString`]. See [`with_capacity`] defined on [`OsString`].
1160 /// use std::path::PathBuf;
1162 /// let mut path = PathBuf::with_capacity(10);
1163 /// let capacity = path.capacity();
1165 /// // This push is done without reallocating
1166 /// path.push(r"C:\");
1168 /// assert_eq!(capacity, path.capacity());
1171 /// [`with_capacity`]: OsString::with_capacity
1172 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1174 pub fn with_capacity(capacity: usize) -> PathBuf {
1175 PathBuf { inner: OsString::with_capacity(capacity) }
1178 /// Coerces to a [`Path`] slice.
1183 /// use std::path::{Path, PathBuf};
1185 /// let p = PathBuf::from("/test");
1186 /// assert_eq!(Path::new("/test"), p.as_path());
1188 #[stable(feature = "rust1", since = "1.0.0")]
1190 pub fn as_path(&self) -> &Path {
1194 /// Extends `self` with `path`.
1196 /// If `path` is absolute, it replaces the current path.
1200 /// * if `path` has a root but no prefix (e.g., `\windows`), it
1201 /// replaces everything except for the prefix (if any) of `self`.
1202 /// * if `path` has a prefix but no root, it replaces `self`.
1206 /// Pushing a relative path extends the existing path:
1209 /// use std::path::PathBuf;
1211 /// let mut path = PathBuf::from("/tmp");
1212 /// path.push("file.bk");
1213 /// assert_eq!(path, PathBuf::from("/tmp/file.bk"));
1216 /// Pushing an absolute path replaces the existing path:
1219 /// use std::path::PathBuf;
1221 /// let mut path = PathBuf::from("/tmp");
1222 /// path.push("/etc");
1223 /// assert_eq!(path, PathBuf::from("/etc"));
1225 #[stable(feature = "rust1", since = "1.0.0")]
1226 pub fn push<P: AsRef<Path>>(&mut self, path: P) {
1227 self._push(path.as_ref())
1230 fn _push(&mut self, path: &Path) {
1231 // in general, a separator is needed if the rightmost byte is not a separator
1232 let mut need_sep = self.as_mut_vec().last().map(|c| !is_sep_byte(*c)).unwrap_or(false);
1234 // in the special case of `C:` on Windows, do *not* add a separator
1235 let comps = self.components();
1237 if comps.prefix_len() > 0
1238 && comps.prefix_len() == comps.path.len()
1239 && comps.prefix.unwrap().is_drive()
1244 // absolute `path` replaces `self`
1245 if path.is_absolute() || path.prefix().is_some() {
1246 self.as_mut_vec().truncate(0);
1248 // verbatim paths need . and .. removed
1249 } else if comps.prefix_verbatim() {
1250 let mut buf: Vec<_> = comps.collect();
1251 for c in path.components() {
1253 Component::RootDir => {
1257 Component::CurDir => (),
1258 Component::ParentDir => {
1259 if let Some(Component::Normal(_)) = buf.last() {
1267 let mut res = OsString::new();
1268 let mut need_sep = false;
1271 if need_sep && c != Component::RootDir {
1272 res.push(MAIN_SEP_STR);
1274 res.push(c.as_os_str());
1276 need_sep = match c {
1277 Component::RootDir => false,
1278 Component::Prefix(prefix) => {
1279 !prefix.parsed.is_drive() && prefix.parsed.len() > 0
1288 // `path` has a root but no prefix, e.g., `\windows` (Windows only)
1289 } else if path.has_root() {
1290 let prefix_len = self.components().prefix_remaining();
1291 self.as_mut_vec().truncate(prefix_len);
1293 // `path` is a pure relative path
1294 } else if need_sep {
1295 self.inner.push(MAIN_SEP_STR);
1298 self.inner.push(path);
1301 /// Truncates `self` to [`self.parent`].
1303 /// Returns `false` and does nothing if [`self.parent`] is [`None`].
1304 /// Otherwise, returns `true`.
1306 /// [`self.parent`]: Path::parent
1311 /// use std::path::{Path, PathBuf};
1313 /// let mut p = PathBuf::from("/spirited/away.rs");
1316 /// assert_eq!(Path::new("/spirited"), p);
1318 /// assert_eq!(Path::new("/"), p);
1320 #[stable(feature = "rust1", since = "1.0.0")]
1321 pub fn pop(&mut self) -> bool {
1322 match self.parent().map(|p| p.as_u8_slice().len()) {
1324 self.as_mut_vec().truncate(len);
1331 /// Updates [`self.file_name`] to `file_name`.
1333 /// If [`self.file_name`] was [`None`], this is equivalent to pushing
1336 /// Otherwise it is equivalent to calling [`pop`] and then pushing
1337 /// `file_name`. The new path will be a sibling of the original path.
1338 /// (That is, it will have the same parent.)
1340 /// [`self.file_name`]: Path::file_name
1341 /// [`pop`]: PathBuf::pop
1346 /// use std::path::PathBuf;
1348 /// let mut buf = PathBuf::from("/");
1349 /// assert!(buf.file_name() == None);
1350 /// buf.set_file_name("bar");
1351 /// assert!(buf == PathBuf::from("/bar"));
1352 /// assert!(buf.file_name().is_some());
1353 /// buf.set_file_name("baz.txt");
1354 /// assert!(buf == PathBuf::from("/baz.txt"));
1356 #[stable(feature = "rust1", since = "1.0.0")]
1357 pub fn set_file_name<S: AsRef<OsStr>>(&mut self, file_name: S) {
1358 self._set_file_name(file_name.as_ref())
1361 fn _set_file_name(&mut self, file_name: &OsStr) {
1362 if self.file_name().is_some() {
1363 let popped = self.pop();
1364 debug_assert!(popped);
1366 self.push(file_name);
1369 /// Updates [`self.extension`] to `extension`.
1371 /// Returns `false` and does nothing if [`self.file_name`] is [`None`],
1372 /// returns `true` and updates the extension otherwise.
1374 /// If [`self.extension`] is [`None`], the extension is added; otherwise
1377 /// [`self.file_name`]: Path::file_name
1378 /// [`self.extension`]: Path::extension
1383 /// use std::path::{Path, PathBuf};
1385 /// let mut p = PathBuf::from("/feel/the");
1387 /// p.set_extension("force");
1388 /// assert_eq!(Path::new("/feel/the.force"), p.as_path());
1390 /// p.set_extension("dark_side");
1391 /// assert_eq!(Path::new("/feel/the.dark_side"), p.as_path());
1393 #[stable(feature = "rust1", since = "1.0.0")]
1394 pub fn set_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> bool {
1395 self._set_extension(extension.as_ref())
1398 fn _set_extension(&mut self, extension: &OsStr) -> bool {
1399 let file_stem = match self.file_stem() {
1400 None => return false,
1401 Some(f) => os_str_as_u8_slice(f),
1404 // truncate until right after the file stem
1405 let end_file_stem = file_stem[file_stem.len()..].as_ptr() as usize;
1406 let start = os_str_as_u8_slice(&self.inner).as_ptr() as usize;
1407 let v = self.as_mut_vec();
1408 v.truncate(end_file_stem.wrapping_sub(start));
1410 // add the new extension, if any
1411 let new = os_str_as_u8_slice(extension);
1412 if !new.is_empty() {
1413 v.reserve_exact(new.len() + 1);
1415 v.extend_from_slice(new);
1421 /// Consumes the `PathBuf`, yielding its internal [`OsString`] storage.
1426 /// use std::path::PathBuf;
1428 /// let p = PathBuf::from("/the/head");
1429 /// let os_str = p.into_os_string();
1431 #[stable(feature = "rust1", since = "1.0.0")]
1432 #[must_use = "`self` will be dropped if the result is not used"]
1434 pub fn into_os_string(self) -> OsString {
1438 /// Converts this `PathBuf` into a [boxed](Box) [`Path`].
1439 #[stable(feature = "into_boxed_path", since = "1.20.0")]
1440 #[must_use = "`self` will be dropped if the result is not used"]
1442 pub fn into_boxed_path(self) -> Box<Path> {
1443 let rw = Box::into_raw(self.inner.into_boxed_os_str()) as *mut Path;
1444 unsafe { Box::from_raw(rw) }
1447 /// Invokes [`capacity`] on the underlying instance of [`OsString`].
1449 /// [`capacity`]: OsString::capacity
1450 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1452 pub fn capacity(&self) -> usize {
1453 self.inner.capacity()
1456 /// Invokes [`clear`] on the underlying instance of [`OsString`].
1458 /// [`clear`]: OsString::clear
1459 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1461 pub fn clear(&mut self) {
1465 /// Invokes [`reserve`] on the underlying instance of [`OsString`].
1467 /// [`reserve`]: OsString::reserve
1468 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1470 pub fn reserve(&mut self, additional: usize) {
1471 self.inner.reserve(additional)
1474 /// Invokes [`reserve_exact`] on the underlying instance of [`OsString`].
1476 /// [`reserve_exact`]: OsString::reserve_exact
1477 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1479 pub fn reserve_exact(&mut self, additional: usize) {
1480 self.inner.reserve_exact(additional)
1483 /// Invokes [`shrink_to_fit`] on the underlying instance of [`OsString`].
1485 /// [`shrink_to_fit`]: OsString::shrink_to_fit
1486 #[stable(feature = "path_buf_capacity", since = "1.44.0")]
1488 pub fn shrink_to_fit(&mut self) {
1489 self.inner.shrink_to_fit()
1492 /// Invokes [`shrink_to`] on the underlying instance of [`OsString`].
1494 /// [`shrink_to`]: OsString::shrink_to
1495 #[stable(feature = "shrink_to", since = "1.56.0")]
1497 pub fn shrink_to(&mut self, min_capacity: usize) {
1498 self.inner.shrink_to(min_capacity)
1502 #[stable(feature = "rust1", since = "1.0.0")]
1503 impl Clone for PathBuf {
1505 fn clone(&self) -> Self {
1506 PathBuf { inner: self.inner.clone() }
1510 fn clone_from(&mut self, source: &Self) {
1511 self.inner.clone_from(&source.inner)
1515 #[stable(feature = "box_from_path", since = "1.17.0")]
1516 impl From<&Path> for Box<Path> {
1517 /// Creates a boxed [`Path`] from a reference.
1519 /// This will allocate and clone `path` to it.
1520 fn from(path: &Path) -> Box<Path> {
1521 let boxed: Box<OsStr> = path.inner.into();
1522 let rw = Box::into_raw(boxed) as *mut Path;
1523 unsafe { Box::from_raw(rw) }
1527 #[stable(feature = "box_from_cow", since = "1.45.0")]
1528 impl From<Cow<'_, Path>> for Box<Path> {
1529 /// Creates a boxed [`Path`] from a clone-on-write pointer.
1531 /// Converting from a `Cow::Owned` does not clone or allocate.
1533 fn from(cow: Cow<'_, Path>) -> Box<Path> {
1535 Cow::Borrowed(path) => Box::from(path),
1536 Cow::Owned(path) => Box::from(path),
1541 #[stable(feature = "path_buf_from_box", since = "1.18.0")]
1542 impl From<Box<Path>> for PathBuf {
1543 /// Converts a `Box<Path>` into a `PathBuf`
1545 /// This conversion does not allocate or copy memory.
1547 fn from(boxed: Box<Path>) -> PathBuf {
1548 boxed.into_path_buf()
1552 #[stable(feature = "box_from_path_buf", since = "1.20.0")]
1553 impl From<PathBuf> for Box<Path> {
1554 /// Converts a `PathBuf` into a `Box<Path>`
1556 /// This conversion currently should not allocate memory,
1557 /// but this behavior is not guaranteed on all platforms or in all future versions.
1559 fn from(p: PathBuf) -> Box<Path> {
1564 #[stable(feature = "more_box_slice_clone", since = "1.29.0")]
1565 impl Clone for Box<Path> {
1567 fn clone(&self) -> Self {
1568 self.to_path_buf().into_boxed_path()
1572 #[stable(feature = "rust1", since = "1.0.0")]
1573 impl<T: ?Sized + AsRef<OsStr>> From<&T> for PathBuf {
1574 /// Converts a borrowed `OsStr` to a `PathBuf`.
1576 /// Allocates a [`PathBuf`] and copies the data into it.
1578 fn from(s: &T) -> PathBuf {
1579 PathBuf::from(s.as_ref().to_os_string())
1583 #[stable(feature = "rust1", since = "1.0.0")]
1584 impl From<OsString> for PathBuf {
1585 /// Converts an [`OsString`] into a [`PathBuf`]
1587 /// This conversion does not allocate or copy memory.
1589 fn from(s: OsString) -> PathBuf {
1590 PathBuf { inner: s }
1594 #[stable(feature = "from_path_buf_for_os_string", since = "1.14.0")]
1595 impl From<PathBuf> for OsString {
1596 /// Converts a [`PathBuf`] into an [`OsString`]
1598 /// This conversion does not allocate or copy memory.
1600 fn from(path_buf: PathBuf) -> OsString {
1605 #[stable(feature = "rust1", since = "1.0.0")]
1606 impl From<String> for PathBuf {
1607 /// Converts a [`String`] into a [`PathBuf`]
1609 /// This conversion does not allocate or copy memory.
1611 fn from(s: String) -> PathBuf {
1612 PathBuf::from(OsString::from(s))
1616 #[stable(feature = "path_from_str", since = "1.32.0")]
1617 impl FromStr for PathBuf {
1618 type Err = core::convert::Infallible;
1621 fn from_str(s: &str) -> Result<Self, Self::Err> {
1622 Ok(PathBuf::from(s))
1626 #[stable(feature = "rust1", since = "1.0.0")]
1627 impl<P: AsRef<Path>> iter::FromIterator<P> for PathBuf {
1628 fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> PathBuf {
1629 let mut buf = PathBuf::new();
1635 #[stable(feature = "rust1", since = "1.0.0")]
1636 impl<P: AsRef<Path>> iter::Extend<P> for PathBuf {
1637 fn extend<I: IntoIterator<Item = P>>(&mut self, iter: I) {
1638 iter.into_iter().for_each(move |p| self.push(p.as_ref()));
1642 fn extend_one(&mut self, p: P) {
1643 self.push(p.as_ref());
1647 #[stable(feature = "rust1", since = "1.0.0")]
1648 impl fmt::Debug for PathBuf {
1649 fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
1650 fmt::Debug::fmt(&**self, formatter)
1654 #[stable(feature = "rust1", since = "1.0.0")]
1655 impl ops::Deref for PathBuf {
1658 fn deref(&self) -> &Path {
1659 Path::new(&self.inner)
1663 #[stable(feature = "rust1", since = "1.0.0")]
1664 impl Borrow<Path> for PathBuf {
1666 fn borrow(&self) -> &Path {
1671 #[stable(feature = "default_for_pathbuf", since = "1.17.0")]
1672 impl Default for PathBuf {
1674 fn default() -> Self {
1679 #[stable(feature = "cow_from_path", since = "1.6.0")]
1680 impl<'a> From<&'a Path> for Cow<'a, Path> {
1681 /// Creates a clone-on-write pointer from a reference to
1684 /// This conversion does not clone or allocate.
1686 fn from(s: &'a Path) -> Cow<'a, Path> {
1691 #[stable(feature = "cow_from_path", since = "1.6.0")]
1692 impl<'a> From<PathBuf> for Cow<'a, Path> {
1693 /// Creates a clone-on-write pointer from an owned
1694 /// instance of [`PathBuf`].
1696 /// This conversion does not clone or allocate.
1698 fn from(s: PathBuf) -> Cow<'a, Path> {
1703 #[stable(feature = "cow_from_pathbuf_ref", since = "1.28.0")]
1704 impl<'a> From<&'a PathBuf> for Cow<'a, Path> {
1705 /// Creates a clone-on-write pointer from a reference to
1708 /// This conversion does not clone or allocate.
1710 fn from(p: &'a PathBuf) -> Cow<'a, Path> {
1711 Cow::Borrowed(p.as_path())
1715 #[stable(feature = "pathbuf_from_cow_path", since = "1.28.0")]
1716 impl<'a> From<Cow<'a, Path>> for PathBuf {
1717 /// Converts a clone-on-write pointer to an owned path.
1719 /// Converting from a `Cow::Owned` does not clone or allocate.
1721 fn from(p: Cow<'a, Path>) -> Self {
1726 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1727 impl From<PathBuf> for Arc<Path> {
1728 /// Converts a [`PathBuf`] into an [`Arc`] by moving the [`PathBuf`] data into a new [`Arc`] buffer.
1730 fn from(s: PathBuf) -> Arc<Path> {
1731 let arc: Arc<OsStr> = Arc::from(s.into_os_string());
1732 unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) }
1736 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1737 impl From<&Path> for Arc<Path> {
1738 /// Converts a [`Path`] into an [`Arc`] by copying the [`Path`] data into a new [`Arc`] buffer.
1740 fn from(s: &Path) -> Arc<Path> {
1741 let arc: Arc<OsStr> = Arc::from(s.as_os_str());
1742 unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) }
1746 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1747 impl From<PathBuf> for Rc<Path> {
1748 /// Converts a [`PathBuf`] into an [`Rc`] by moving the [`PathBuf`] data into a new `Rc` buffer.
1750 fn from(s: PathBuf) -> Rc<Path> {
1751 let rc: Rc<OsStr> = Rc::from(s.into_os_string());
1752 unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) }
1756 #[stable(feature = "shared_from_slice2", since = "1.24.0")]
1757 impl From<&Path> for Rc<Path> {
1758 /// Converts a [`Path`] into an [`Rc`] by copying the [`Path`] data into a new `Rc` buffer.
1760 fn from(s: &Path) -> Rc<Path> {
1761 let rc: Rc<OsStr> = Rc::from(s.as_os_str());
1762 unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) }
1766 #[stable(feature = "rust1", since = "1.0.0")]
1767 impl ToOwned for Path {
1768 type Owned = PathBuf;
1770 fn to_owned(&self) -> PathBuf {
1774 fn clone_into(&self, target: &mut PathBuf) {
1775 self.inner.clone_into(&mut target.inner);
1779 #[stable(feature = "rust1", since = "1.0.0")]
1780 impl cmp::PartialEq for PathBuf {
1782 fn eq(&self, other: &PathBuf) -> bool {
1783 self.components() == other.components()
1787 #[stable(feature = "rust1", since = "1.0.0")]
1788 impl Hash for PathBuf {
1789 fn hash<H: Hasher>(&self, h: &mut H) {
1790 self.as_path().hash(h)
1794 #[stable(feature = "rust1", since = "1.0.0")]
1795 impl cmp::Eq for PathBuf {}
1797 #[stable(feature = "rust1", since = "1.0.0")]
1798 impl cmp::PartialOrd for PathBuf {
1800 fn partial_cmp(&self, other: &PathBuf) -> Option<cmp::Ordering> {
1801 Some(compare_components(self.components(), other.components()))
1805 #[stable(feature = "rust1", since = "1.0.0")]
1806 impl cmp::Ord for PathBuf {
1808 fn cmp(&self, other: &PathBuf) -> cmp::Ordering {
1809 compare_components(self.components(), other.components())
1813 #[stable(feature = "rust1", since = "1.0.0")]
1814 impl AsRef<OsStr> for PathBuf {
1816 fn as_ref(&self) -> &OsStr {
1821 /// A slice of a path (akin to [`str`]).
1823 /// This type supports a number of operations for inspecting a path, including
1824 /// breaking the path into its components (separated by `/` on Unix and by either
1825 /// `/` or `\` on Windows), extracting the file name, determining whether the path
1826 /// is absolute, and so on.
1828 /// This is an *unsized* type, meaning that it must always be used behind a
1829 /// pointer like `&` or [`Box`]. For an owned version of this type,
1830 /// see [`PathBuf`].
1832 /// More details about the overall approach can be found in
1833 /// the [module documentation](self).
1838 /// use std::path::Path;
1839 /// use std::ffi::OsStr;
1841 /// // Note: this example does work on Windows
1842 /// let path = Path::new("./foo/bar.txt");
1844 /// let parent = path.parent();
1845 /// assert_eq!(parent, Some(Path::new("./foo")));
1847 /// let file_stem = path.file_stem();
1848 /// assert_eq!(file_stem, Some(OsStr::new("bar")));
1850 /// let extension = path.extension();
1851 /// assert_eq!(extension, Some(OsStr::new("txt")));
1853 #[cfg_attr(not(test), rustc_diagnostic_item = "Path")]
1854 #[stable(feature = "rust1", since = "1.0.0")]
1856 // `Path::new` current implementation relies
1857 // on `Path` being layout-compatible with `OsStr`.
1858 // When attribute privacy is implemented, `Path` should be annotated as `#[repr(transparent)]`.
1859 // Anyway, `Path` representation and layout are considered implementation detail, are
1860 // not documented and must not be relied upon.
1865 /// An error returned from [`Path::strip_prefix`] if the prefix was not found.
1867 /// This `struct` is created by the [`strip_prefix`] method on [`Path`].
1868 /// See its documentation for more.
1870 /// [`strip_prefix`]: Path::strip_prefix
1871 #[derive(Debug, Clone, PartialEq, Eq)]
1872 #[stable(since = "1.7.0", feature = "strip_prefix")]
1873 pub struct StripPrefixError(());
1876 // The following (private!) function allows construction of a path from a u8
1877 // slice, which is only safe when it is known to follow the OsStr encoding.
1878 unsafe fn from_u8_slice(s: &[u8]) -> &Path {
1879 unsafe { Path::new(u8_slice_as_os_str(s)) }
1881 // The following (private!) function reveals the byte encoding used for OsStr.
1882 fn as_u8_slice(&self) -> &[u8] {
1883 os_str_as_u8_slice(&self.inner)
1886 /// Directly wraps a string slice as a `Path` slice.
1888 /// This is a cost-free conversion.
1893 /// use std::path::Path;
1895 /// Path::new("foo.txt");
1898 /// You can create `Path`s from `String`s, or even other `Path`s:
1901 /// use std::path::Path;
1903 /// let string = String::from("foo.txt");
1904 /// let from_string = Path::new(&string);
1905 /// let from_path = Path::new(&from_string);
1906 /// assert_eq!(from_string, from_path);
1908 #[stable(feature = "rust1", since = "1.0.0")]
1909 pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &Path {
1910 unsafe { &*(s.as_ref() as *const OsStr as *const Path) }
1913 /// Yields the underlying [`OsStr`] slice.
1918 /// use std::path::Path;
1920 /// let os_str = Path::new("foo.txt").as_os_str();
1921 /// assert_eq!(os_str, std::ffi::OsStr::new("foo.txt"));
1923 #[stable(feature = "rust1", since = "1.0.0")]
1925 pub fn as_os_str(&self) -> &OsStr {
1929 /// Yields a [`&str`] slice if the `Path` is valid unicode.
1931 /// This conversion may entail doing a check for UTF-8 validity.
1932 /// Note that validation is performed because non-UTF-8 strings are
1933 /// perfectly valid for some OS.
1940 /// use std::path::Path;
1942 /// let path = Path::new("foo.txt");
1943 /// assert_eq!(path.to_str(), Some("foo.txt"));
1945 #[stable(feature = "rust1", since = "1.0.0")]
1947 pub fn to_str(&self) -> Option<&str> {
1951 /// Converts a `Path` to a [`Cow<str>`].
1953 /// Any non-Unicode sequences are replaced with
1954 /// [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD].
1956 /// [U+FFFD]: super::char::REPLACEMENT_CHARACTER
1960 /// Calling `to_string_lossy` on a `Path` with valid unicode:
1963 /// use std::path::Path;
1965 /// let path = Path::new("foo.txt");
1966 /// assert_eq!(path.to_string_lossy(), "foo.txt");
1969 /// Had `path` contained invalid unicode, the `to_string_lossy` call might
1970 /// have returned `"fo�.txt"`.
1971 #[stable(feature = "rust1", since = "1.0.0")]
1973 pub fn to_string_lossy(&self) -> Cow<'_, str> {
1974 self.inner.to_string_lossy()
1977 /// Converts a `Path` to an owned [`PathBuf`].
1982 /// use std::path::Path;
1984 /// let path_buf = Path::new("foo.txt").to_path_buf();
1985 /// assert_eq!(path_buf, std::path::PathBuf::from("foo.txt"));
1987 #[rustc_conversion_suggestion]
1988 #[stable(feature = "rust1", since = "1.0.0")]
1989 pub fn to_path_buf(&self) -> PathBuf {
1990 PathBuf::from(self.inner.to_os_string())
1993 /// Returns `true` if the `Path` is absolute, i.e., if it is independent of
1994 /// the current directory.
1996 /// * On Unix, a path is absolute if it starts with the root, so
1997 /// `is_absolute` and [`has_root`] are equivalent.
1999 /// * On Windows, a path is absolute if it has a prefix and starts with the
2000 /// root: `c:\windows` is absolute, while `c:temp` and `\temp` are not.
2005 /// use std::path::Path;
2007 /// assert!(!Path::new("foo.txt").is_absolute());
2010 /// [`has_root`]: Path::has_root
2011 #[stable(feature = "rust1", since = "1.0.0")]
2012 #[allow(deprecated)]
2013 pub fn is_absolute(&self) -> bool {
2014 if cfg!(target_os = "redox") {
2015 // FIXME: Allow Redox prefixes
2016 self.has_root() || has_redox_scheme(self.as_u8_slice())
2018 self.has_root() && (cfg!(any(unix, target_os = "wasi")) || self.prefix().is_some())
2022 /// Returns `true` if the `Path` is relative, i.e., not absolute.
2024 /// See [`is_absolute`]'s documentation for more details.
2029 /// use std::path::Path;
2031 /// assert!(Path::new("foo.txt").is_relative());
2034 /// [`is_absolute`]: Path::is_absolute
2035 #[stable(feature = "rust1", since = "1.0.0")]
2037 pub fn is_relative(&self) -> bool {
2041 fn prefix(&self) -> Option<Prefix<'_>> {
2042 self.components().prefix
2045 /// Returns `true` if the `Path` has a root.
2047 /// * On Unix, a path has a root if it begins with `/`.
2049 /// * On Windows, a path has a root if it:
2050 /// * has no prefix and begins with a separator, e.g., `\windows`
2051 /// * has a prefix followed by a separator, e.g., `c:\windows` but not `c:windows`
2052 /// * has any non-disk prefix, e.g., `\\server\share`
2057 /// use std::path::Path;
2059 /// assert!(Path::new("/etc/passwd").has_root());
2061 #[stable(feature = "rust1", since = "1.0.0")]
2063 pub fn has_root(&self) -> bool {
2064 self.components().has_root()
2067 /// Returns the `Path` without its final component, if there is one.
2069 /// Returns [`None`] if the path terminates in a root or prefix.
2074 /// use std::path::Path;
2076 /// let path = Path::new("/foo/bar");
2077 /// let parent = path.parent().unwrap();
2078 /// assert_eq!(parent, Path::new("/foo"));
2080 /// let grand_parent = parent.parent().unwrap();
2081 /// assert_eq!(grand_parent, Path::new("/"));
2082 /// assert_eq!(grand_parent.parent(), None);
2084 #[stable(feature = "rust1", since = "1.0.0")]
2085 pub fn parent(&self) -> Option<&Path> {
2086 let mut comps = self.components();
2087 let comp = comps.next_back();
2088 comp.and_then(|p| match p {
2089 Component::Normal(_) | Component::CurDir | Component::ParentDir => {
2090 Some(comps.as_path())
2096 /// Produces an iterator over `Path` and its ancestors.
2098 /// The iterator will yield the `Path` that is returned if the [`parent`] method is used zero
2099 /// or more times. That means, the iterator will yield `&self`, `&self.parent().unwrap()`,
2100 /// `&self.parent().unwrap().parent().unwrap()` and so on. If the [`parent`] method returns
2101 /// [`None`], the iterator will do likewise. The iterator will always yield at least one value,
2107 /// use std::path::Path;
2109 /// let mut ancestors = Path::new("/foo/bar").ancestors();
2110 /// assert_eq!(ancestors.next(), Some(Path::new("/foo/bar")));
2111 /// assert_eq!(ancestors.next(), Some(Path::new("/foo")));
2112 /// assert_eq!(ancestors.next(), Some(Path::new("/")));
2113 /// assert_eq!(ancestors.next(), None);
2115 /// let mut ancestors = Path::new("../foo/bar").ancestors();
2116 /// assert_eq!(ancestors.next(), Some(Path::new("../foo/bar")));
2117 /// assert_eq!(ancestors.next(), Some(Path::new("../foo")));
2118 /// assert_eq!(ancestors.next(), Some(Path::new("..")));
2119 /// assert_eq!(ancestors.next(), Some(Path::new("")));
2120 /// assert_eq!(ancestors.next(), None);
2123 /// [`parent`]: Path::parent
2124 #[stable(feature = "path_ancestors", since = "1.28.0")]
2126 pub fn ancestors(&self) -> Ancestors<'_> {
2127 Ancestors { next: Some(&self) }
2130 /// Returns the final component of the `Path`, if there is one.
2132 /// If the path is a normal file, this is the file name. If it's the path of a directory, this
2133 /// is the directory name.
2135 /// Returns [`None`] if the path terminates in `..`.
2140 /// use std::path::Path;
2141 /// use std::ffi::OsStr;
2143 /// assert_eq!(Some(OsStr::new("bin")), Path::new("/usr/bin/").file_name());
2144 /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("tmp/foo.txt").file_name());
2145 /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name());
2146 /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name());
2147 /// assert_eq!(None, Path::new("foo.txt/..").file_name());
2148 /// assert_eq!(None, Path::new("/").file_name());
2150 #[stable(feature = "rust1", since = "1.0.0")]
2151 pub fn file_name(&self) -> Option<&OsStr> {
2152 self.components().next_back().and_then(|p| match p {
2153 Component::Normal(p) => Some(p),
2158 /// Returns a path that, when joined onto `base`, yields `self`.
2162 /// If `base` is not a prefix of `self` (i.e., [`starts_with`]
2163 /// returns `false`), returns [`Err`].
2165 /// [`starts_with`]: Path::starts_with
2170 /// use std::path::{Path, PathBuf};
2172 /// let path = Path::new("/test/haha/foo.txt");
2174 /// assert_eq!(path.strip_prefix("/"), Ok(Path::new("test/haha/foo.txt")));
2175 /// assert_eq!(path.strip_prefix("/test"), Ok(Path::new("haha/foo.txt")));
2176 /// assert_eq!(path.strip_prefix("/test/"), Ok(Path::new("haha/foo.txt")));
2177 /// assert_eq!(path.strip_prefix("/test/haha/foo.txt"), Ok(Path::new("")));
2178 /// assert_eq!(path.strip_prefix("/test/haha/foo.txt/"), Ok(Path::new("")));
2180 /// assert!(path.strip_prefix("test").is_err());
2181 /// assert!(path.strip_prefix("/haha").is_err());
2183 /// let prefix = PathBuf::from("/test/");
2184 /// assert_eq!(path.strip_prefix(prefix), Ok(Path::new("haha/foo.txt")));
2186 #[stable(since = "1.7.0", feature = "path_strip_prefix")]
2187 pub fn strip_prefix<P>(&self, base: P) -> Result<&Path, StripPrefixError>
2191 self._strip_prefix(base.as_ref())
2194 fn _strip_prefix(&self, base: &Path) -> Result<&Path, StripPrefixError> {
2195 iter_after(self.components(), base.components())
2196 .map(|c| c.as_path())
2197 .ok_or(StripPrefixError(()))
2200 /// Determines whether `base` is a prefix of `self`.
2202 /// Only considers whole path components to match.
2207 /// use std::path::Path;
2209 /// let path = Path::new("/etc/passwd");
2211 /// assert!(path.starts_with("/etc"));
2212 /// assert!(path.starts_with("/etc/"));
2213 /// assert!(path.starts_with("/etc/passwd"));
2214 /// assert!(path.starts_with("/etc/passwd/")); // extra slash is okay
2215 /// assert!(path.starts_with("/etc/passwd///")); // multiple extra slashes are okay
2217 /// assert!(!path.starts_with("/e"));
2218 /// assert!(!path.starts_with("/etc/passwd.txt"));
2220 /// assert!(!Path::new("/etc/foo.rs").starts_with("/etc/foo"));
2222 #[stable(feature = "rust1", since = "1.0.0")]
2223 pub fn starts_with<P: AsRef<Path>>(&self, base: P) -> bool {
2224 self._starts_with(base.as_ref())
2227 fn _starts_with(&self, base: &Path) -> bool {
2228 iter_after(self.components(), base.components()).is_some()
2231 /// Determines whether `child` is a suffix of `self`.
2233 /// Only considers whole path components to match.
2238 /// use std::path::Path;
2240 /// let path = Path::new("/etc/resolv.conf");
2242 /// assert!(path.ends_with("resolv.conf"));
2243 /// assert!(path.ends_with("etc/resolv.conf"));
2244 /// assert!(path.ends_with("/etc/resolv.conf"));
2246 /// assert!(!path.ends_with("/resolv.conf"));
2247 /// assert!(!path.ends_with("conf")); // use .extension() instead
2249 #[stable(feature = "rust1", since = "1.0.0")]
2250 pub fn ends_with<P: AsRef<Path>>(&self, child: P) -> bool {
2251 self._ends_with(child.as_ref())
2254 fn _ends_with(&self, child: &Path) -> bool {
2255 iter_after(self.components().rev(), child.components().rev()).is_some()
2258 /// Extracts the stem (non-extension) portion of [`self.file_name`].
2260 /// [`self.file_name`]: Path::file_name
2264 /// * [`None`], if there is no file name;
2265 /// * The entire file name if there is no embedded `.`;
2266 /// * The entire file name if the file name begins with `.` and has no other `.`s within;
2267 /// * Otherwise, the portion of the file name before the final `.`
2272 /// use std::path::Path;
2274 /// assert_eq!("foo", Path::new("foo.rs").file_stem().unwrap());
2275 /// assert_eq!("foo.tar", Path::new("foo.tar.gz").file_stem().unwrap());
2279 /// This method is similar to [`Path::file_prefix`], which extracts the portion of the file name
2280 /// before the *first* `.`
2282 /// [`Path::file_prefix`]: Path::file_prefix
2284 #[stable(feature = "rust1", since = "1.0.0")]
2285 pub fn file_stem(&self) -> Option<&OsStr> {
2286 self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.or(after))
2289 /// Extracts the prefix of [`self.file_name`].
2293 /// * [`None`], if there is no file name;
2294 /// * The entire file name if there is no embedded `.`;
2295 /// * The portion of the file name before the first non-beginning `.`;
2296 /// * The entire file name if the file name begins with `.` and has no other `.`s within;
2297 /// * The portion of the file name before the second `.` if the file name begins with `.`
2299 /// [`self.file_name`]: Path::file_name
2304 /// # #![feature(path_file_prefix)]
2305 /// use std::path::Path;
2307 /// assert_eq!("foo", Path::new("foo.rs").file_prefix().unwrap());
2308 /// assert_eq!("foo", Path::new("foo.tar.gz").file_prefix().unwrap());
2312 /// This method is similar to [`Path::file_stem`], which extracts the portion of the file name
2313 /// before the *last* `.`
2315 /// [`Path::file_stem`]: Path::file_stem
2317 #[unstable(feature = "path_file_prefix", issue = "86319")]
2318 pub fn file_prefix(&self) -> Option<&OsStr> {
2319 self.file_name().map(split_file_at_dot).and_then(|(before, _after)| Some(before))
2322 /// Extracts the extension of [`self.file_name`], if possible.
2324 /// The extension is:
2326 /// * [`None`], if there is no file name;
2327 /// * [`None`], if there is no embedded `.`;
2328 /// * [`None`], if the file name begins with `.` and has no other `.`s within;
2329 /// * Otherwise, the portion of the file name after the final `.`
2331 /// [`self.file_name`]: Path::file_name
2336 /// use std::path::Path;
2338 /// assert_eq!("rs", Path::new("foo.rs").extension().unwrap());
2339 /// assert_eq!("gz", Path::new("foo.tar.gz").extension().unwrap());
2341 #[stable(feature = "rust1", since = "1.0.0")]
2342 pub fn extension(&self) -> Option<&OsStr> {
2343 self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.and(after))
2346 /// Creates an owned [`PathBuf`] with `path` adjoined to `self`.
2348 /// See [`PathBuf::push`] for more details on what it means to adjoin a path.
2353 /// use std::path::{Path, PathBuf};
2355 /// assert_eq!(Path::new("/etc").join("passwd"), PathBuf::from("/etc/passwd"));
2357 #[stable(feature = "rust1", since = "1.0.0")]
2359 pub fn join<P: AsRef<Path>>(&self, path: P) -> PathBuf {
2360 self._join(path.as_ref())
2363 fn _join(&self, path: &Path) -> PathBuf {
2364 let mut buf = self.to_path_buf();
2369 /// Creates an owned [`PathBuf`] like `self` but with the given file name.
2371 /// See [`PathBuf::set_file_name`] for more details.
2376 /// use std::path::{Path, PathBuf};
2378 /// let path = Path::new("/tmp/foo.txt");
2379 /// assert_eq!(path.with_file_name("bar.txt"), PathBuf::from("/tmp/bar.txt"));
2381 /// let path = Path::new("/tmp");
2382 /// assert_eq!(path.with_file_name("var"), PathBuf::from("/var"));
2384 #[stable(feature = "rust1", since = "1.0.0")]
2385 pub fn with_file_name<S: AsRef<OsStr>>(&self, file_name: S) -> PathBuf {
2386 self._with_file_name(file_name.as_ref())
2389 fn _with_file_name(&self, file_name: &OsStr) -> PathBuf {
2390 let mut buf = self.to_path_buf();
2391 buf.set_file_name(file_name);
2395 /// Creates an owned [`PathBuf`] like `self` but with the given extension.
2397 /// See [`PathBuf::set_extension`] for more details.
2402 /// use std::path::{Path, PathBuf};
2404 /// let path = Path::new("foo.rs");
2405 /// assert_eq!(path.with_extension("txt"), PathBuf::from("foo.txt"));
2407 /// let path = Path::new("foo.tar.gz");
2408 /// assert_eq!(path.with_extension(""), PathBuf::from("foo.tar"));
2409 /// assert_eq!(path.with_extension("xz"), PathBuf::from("foo.tar.xz"));
2410 /// assert_eq!(path.with_extension("").with_extension("txt"), PathBuf::from("foo.txt"));
2412 #[stable(feature = "rust1", since = "1.0.0")]
2413 pub fn with_extension<S: AsRef<OsStr>>(&self, extension: S) -> PathBuf {
2414 self._with_extension(extension.as_ref())
2417 fn _with_extension(&self, extension: &OsStr) -> PathBuf {
2418 let mut buf = self.to_path_buf();
2419 buf.set_extension(extension);
2423 /// Produces an iterator over the [`Component`]s of the path.
2425 /// When parsing the path, there is a small amount of normalization:
2427 /// * Repeated separators are ignored, so `a/b` and `a//b` both have
2428 /// `a` and `b` as components.
2430 /// * Occurrences of `.` are normalized away, except if they are at the
2431 /// beginning of the path. For example, `a/./b`, `a/b/`, `a/b/.` and
2432 /// `a/b` all have `a` and `b` as components, but `./a/b` starts with
2433 /// an additional [`CurDir`] component.
2435 /// * A trailing slash is normalized away, `/a/b` and `/a/b/` are equivalent.
2437 /// Note that no other normalization takes place; in particular, `a/c`
2438 /// and `a/b/../c` are distinct, to account for the possibility that `b`
2439 /// is a symbolic link (so its parent isn't `a`).
2444 /// use std::path::{Path, Component};
2445 /// use std::ffi::OsStr;
2447 /// let mut components = Path::new("/tmp/foo.txt").components();
2449 /// assert_eq!(components.next(), Some(Component::RootDir));
2450 /// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("tmp"))));
2451 /// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("foo.txt"))));
2452 /// assert_eq!(components.next(), None)
2455 /// [`CurDir`]: Component::CurDir
2456 #[stable(feature = "rust1", since = "1.0.0")]
2457 pub fn components(&self) -> Components<'_> {
2458 let prefix = parse_prefix(self.as_os_str());
2460 path: self.as_u8_slice(),
2462 has_physical_root: has_physical_root(self.as_u8_slice(), prefix)
2463 || has_redox_scheme(self.as_u8_slice()),
2464 front: State::Prefix,
2469 /// Produces an iterator over the path's components viewed as [`OsStr`]
2472 /// For more information about the particulars of how the path is separated
2473 /// into components, see [`components`].
2475 /// [`components`]: Path::components
2480 /// use std::path::{self, Path};
2481 /// use std::ffi::OsStr;
2483 /// let mut it = Path::new("/tmp/foo.txt").iter();
2484 /// assert_eq!(it.next(), Some(OsStr::new(&path::MAIN_SEPARATOR.to_string())));
2485 /// assert_eq!(it.next(), Some(OsStr::new("tmp")));
2486 /// assert_eq!(it.next(), Some(OsStr::new("foo.txt")));
2487 /// assert_eq!(it.next(), None)
2489 #[stable(feature = "rust1", since = "1.0.0")]
2491 pub fn iter(&self) -> Iter<'_> {
2492 Iter { inner: self.components() }
2495 /// Returns an object that implements [`Display`] for safely printing paths
2496 /// that may contain non-Unicode data. This may perform lossy conversion,
2497 /// depending on the platform. If you would like an implementation which
2498 /// escapes the path please use [`Debug`] instead.
2500 /// [`Display`]: fmt::Display
2505 /// use std::path::Path;
2507 /// let path = Path::new("/tmp/foo.rs");
2509 /// println!("{}", path.display());
2511 #[stable(feature = "rust1", since = "1.0.0")]
2513 pub fn display(&self) -> Display<'_> {
2514 Display { path: self }
2517 /// Queries the file system to get information about a file, directory, etc.
2519 /// This function will traverse symbolic links to query information about the
2520 /// destination file.
2522 /// This is an alias to [`fs::metadata`].
2527 /// use std::path::Path;
2529 /// let path = Path::new("/Minas/tirith");
2530 /// let metadata = path.metadata().expect("metadata call failed");
2531 /// println!("{:?}", metadata.file_type());
2533 #[stable(feature = "path_ext", since = "1.5.0")]
2535 pub fn metadata(&self) -> io::Result<fs::Metadata> {
2539 /// Queries the metadata about a file without following symlinks.
2541 /// This is an alias to [`fs::symlink_metadata`].
2546 /// use std::path::Path;
2548 /// let path = Path::new("/Minas/tirith");
2549 /// let metadata = path.symlink_metadata().expect("symlink_metadata call failed");
2550 /// println!("{:?}", metadata.file_type());
2552 #[stable(feature = "path_ext", since = "1.5.0")]
2554 pub fn symlink_metadata(&self) -> io::Result<fs::Metadata> {
2555 fs::symlink_metadata(self)
2558 /// Returns the canonical, absolute form of the path with all intermediate
2559 /// components normalized and symbolic links resolved.
2561 /// This is an alias to [`fs::canonicalize`].
2566 /// use std::path::{Path, PathBuf};
2568 /// let path = Path::new("/foo/test/../test/bar.rs");
2569 /// assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs"));
2571 #[stable(feature = "path_ext", since = "1.5.0")]
2573 pub fn canonicalize(&self) -> io::Result<PathBuf> {
2574 fs::canonicalize(self)
2577 /// Reads a symbolic link, returning the file that the link points to.
2579 /// This is an alias to [`fs::read_link`].
2584 /// use std::path::Path;
2586 /// let path = Path::new("/laputa/sky_castle.rs");
2587 /// let path_link = path.read_link().expect("read_link call failed");
2589 #[stable(feature = "path_ext", since = "1.5.0")]
2591 pub fn read_link(&self) -> io::Result<PathBuf> {
2595 /// Returns an iterator over the entries within a directory.
2597 /// The iterator will yield instances of <code>[io::Result]<[fs::DirEntry]></code>. New
2598 /// errors may be encountered after an iterator is initially constructed.
2600 /// This is an alias to [`fs::read_dir`].
2605 /// use std::path::Path;
2607 /// let path = Path::new("/laputa");
2608 /// for entry in path.read_dir().expect("read_dir call failed") {
2609 /// if let Ok(entry) = entry {
2610 /// println!("{:?}", entry.path());
2614 #[stable(feature = "path_ext", since = "1.5.0")]
2616 pub fn read_dir(&self) -> io::Result<fs::ReadDir> {
2620 /// Returns `true` if the path points at an existing entity.
2622 /// This function will traverse symbolic links to query information about the
2623 /// destination file.
2625 /// If you cannot access the metadata of the file, e.g. because of a
2626 /// permission error or broken symbolic links, this will return `false`.
2631 /// use std::path::Path;
2632 /// assert!(!Path::new("does_not_exist.txt").exists());
2637 /// This is a convenience function that coerces errors to false. If you want to
2638 /// check errors, call [`fs::metadata`].
2639 #[stable(feature = "path_ext", since = "1.5.0")]
2641 pub fn exists(&self) -> bool {
2642 fs::metadata(self).is_ok()
2645 /// Returns `Ok(true)` if the path points at an existing entity.
2647 /// This function will traverse symbolic links to query information about the
2648 /// destination file. In case of broken symbolic links this will return `Ok(false)`.
2650 /// As opposed to the `exists()` method, this one doesn't silently ignore errors
2651 /// unrelated to the path not existing. (E.g. it will return `Err(_)` in case of permission
2652 /// denied on some of the parent directories.)
2657 /// #![feature(path_try_exists)]
2659 /// use std::path::Path;
2660 /// assert!(!Path::new("does_not_exist.txt").try_exists().expect("Can't check existence of file does_not_exist.txt"));
2661 /// assert!(Path::new("/root/secret_file.txt").try_exists().is_err());
2663 // FIXME: stabilization should modify documentation of `exists()` to recommend this method
2665 #[unstable(feature = "path_try_exists", issue = "83186")]
2667 pub fn try_exists(&self) -> io::Result<bool> {
2668 fs::try_exists(self)
2671 /// Returns `true` if the path exists on disk and is pointing at a regular file.
2673 /// This function will traverse symbolic links to query information about the
2674 /// destination file.
2676 /// If you cannot access the metadata of the file, e.g. because of a
2677 /// permission error or broken symbolic links, this will return `false`.
2682 /// use std::path::Path;
2683 /// assert_eq!(Path::new("./is_a_directory/").is_file(), false);
2684 /// assert_eq!(Path::new("a_file.txt").is_file(), true);
2689 /// This is a convenience function that coerces errors to false. If you want to
2690 /// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call
2691 /// [`fs::Metadata::is_file`] if it was [`Ok`].
2693 /// When the goal is simply to read from (or write to) the source, the most
2694 /// reliable way to test the source can be read (or written to) is to open
2695 /// it. Only using `is_file` can break workflows like `diff <( prog_a )` on
2696 /// a Unix-like system for example. See [`fs::File::open`] or
2697 /// [`fs::OpenOptions::open`] for more information.
2698 #[stable(feature = "path_ext", since = "1.5.0")]
2699 pub fn is_file(&self) -> bool {
2700 fs::metadata(self).map(|m| m.is_file()).unwrap_or(false)
2703 /// Returns `true` if the path exists on disk and is pointing at a directory.
2705 /// This function will traverse symbolic links to query information about the
2706 /// destination file.
2708 /// If you cannot access the metadata of the file, e.g. because of a
2709 /// permission error or broken symbolic links, this will return `false`.
2714 /// use std::path::Path;
2715 /// assert_eq!(Path::new("./is_a_directory/").is_dir(), true);
2716 /// assert_eq!(Path::new("a_file.txt").is_dir(), false);
2721 /// This is a convenience function that coerces errors to false. If you want to
2722 /// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call
2723 /// [`fs::Metadata::is_dir`] if it was [`Ok`].
2724 #[stable(feature = "path_ext", since = "1.5.0")]
2725 pub fn is_dir(&self) -> bool {
2726 fs::metadata(self).map(|m| m.is_dir()).unwrap_or(false)
2729 /// Returns true if the path exists on disk and is pointing at a symbolic link.
2731 /// This function will not traverse symbolic links.
2732 /// In case of a broken symbolic link this will also return true.
2734 /// If you cannot access the directory containing the file, e.g., because of a
2735 /// permission error, this will return false.
2739 #[cfg_attr(unix, doc = "```no_run")]
2740 #[cfg_attr(not(unix), doc = "```ignore")]
2741 /// #![feature(is_symlink)]
2742 /// use std::path::Path;
2743 /// use std::os::unix::fs::symlink;
2745 /// let link_path = Path::new("link");
2746 /// symlink("/origin_does_not_exists/", link_path).unwrap();
2747 /// assert_eq!(link_path.is_symlink(), true);
2748 /// assert_eq!(link_path.exists(), false);
2750 #[unstable(feature = "is_symlink", issue = "85748")]
2751 pub fn is_symlink(&self) -> bool {
2752 fs::symlink_metadata(self).map(|m| m.is_symlink()).unwrap_or(false)
2755 /// Converts a [`Box<Path>`](Box) into a [`PathBuf`] without copying or
2757 #[stable(feature = "into_boxed_path", since = "1.20.0")]
2758 pub fn into_path_buf(self: Box<Path>) -> PathBuf {
2759 let rw = Box::into_raw(self) as *mut OsStr;
2760 let inner = unsafe { Box::from_raw(rw) };
2761 PathBuf { inner: OsString::from(inner) }
2765 #[stable(feature = "rust1", since = "1.0.0")]
2766 impl AsRef<OsStr> for Path {
2768 fn as_ref(&self) -> &OsStr {
2773 #[stable(feature = "rust1", since = "1.0.0")]
2774 impl fmt::Debug for Path {
2775 fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
2776 fmt::Debug::fmt(&self.inner, formatter)
2780 /// Helper struct for safely printing paths with [`format!`] and `{}`.
2782 /// A [`Path`] might contain non-Unicode data. This `struct` implements the
2783 /// [`Display`] trait in a way that mitigates that. It is created by the
2784 /// [`display`](Path::display) method on [`Path`]. This may perform lossy
2785 /// conversion, depending on the platform. If you would like an implementation
2786 /// which escapes the path please use [`Debug`] instead.
2791 /// use std::path::Path;
2793 /// let path = Path::new("/tmp/foo.rs");
2795 /// println!("{}", path.display());
2798 /// [`Display`]: fmt::Display
2799 /// [`format!`]: crate::format
2800 #[stable(feature = "rust1", since = "1.0.0")]
2801 pub struct Display<'a> {
2805 #[stable(feature = "rust1", since = "1.0.0")]
2806 impl fmt::Debug for Display<'_> {
2807 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2808 fmt::Debug::fmt(&self.path, f)
2812 #[stable(feature = "rust1", since = "1.0.0")]
2813 impl fmt::Display for Display<'_> {
2814 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2815 self.path.inner.display(f)
2819 #[stable(feature = "rust1", since = "1.0.0")]
2820 impl cmp::PartialEq for Path {
2822 fn eq(&self, other: &Path) -> bool {
2823 self.components() == other.components()
2827 #[stable(feature = "rust1", since = "1.0.0")]
2828 impl Hash for Path {
2829 fn hash<H: Hasher>(&self, h: &mut H) {
2830 for component in self.components() {
2836 #[stable(feature = "rust1", since = "1.0.0")]
2837 impl cmp::Eq for Path {}
2839 #[stable(feature = "rust1", since = "1.0.0")]
2840 impl cmp::PartialOrd for Path {
2842 fn partial_cmp(&self, other: &Path) -> Option<cmp::Ordering> {
2843 Some(compare_components(self.components(), other.components()))
2847 #[stable(feature = "rust1", since = "1.0.0")]
2848 impl cmp::Ord for Path {
2850 fn cmp(&self, other: &Path) -> cmp::Ordering {
2851 compare_components(self.components(), other.components())
2855 #[stable(feature = "rust1", since = "1.0.0")]
2856 impl AsRef<Path> for Path {
2858 fn as_ref(&self) -> &Path {
2863 #[stable(feature = "rust1", since = "1.0.0")]
2864 impl AsRef<Path> for OsStr {
2866 fn as_ref(&self) -> &Path {
2871 #[stable(feature = "cow_os_str_as_ref_path", since = "1.8.0")]
2872 impl AsRef<Path> for Cow<'_, OsStr> {
2874 fn as_ref(&self) -> &Path {
2879 #[stable(feature = "rust1", since = "1.0.0")]
2880 impl AsRef<Path> for OsString {
2882 fn as_ref(&self) -> &Path {
2887 #[stable(feature = "rust1", since = "1.0.0")]
2888 impl AsRef<Path> for str {
2890 fn as_ref(&self) -> &Path {
2895 #[stable(feature = "rust1", since = "1.0.0")]
2896 impl AsRef<Path> for String {
2898 fn as_ref(&self) -> &Path {
2903 #[stable(feature = "rust1", since = "1.0.0")]
2904 impl AsRef<Path> for PathBuf {
2906 fn as_ref(&self) -> &Path {
2911 #[stable(feature = "path_into_iter", since = "1.6.0")]
2912 impl<'a> IntoIterator for &'a PathBuf {
2913 type Item = &'a OsStr;
2914 type IntoIter = Iter<'a>;
2916 fn into_iter(self) -> Iter<'a> {
2921 #[stable(feature = "path_into_iter", since = "1.6.0")]
2922 impl<'a> IntoIterator for &'a Path {
2923 type Item = &'a OsStr;
2924 type IntoIter = Iter<'a>;
2926 fn into_iter(self) -> Iter<'a> {
2931 macro_rules! impl_cmp {
2932 ($lhs:ty, $rhs: ty) => {
2933 #[stable(feature = "partialeq_path", since = "1.6.0")]
2934 impl<'a, 'b> PartialEq<$rhs> for $lhs {
2936 fn eq(&self, other: &$rhs) -> bool {
2937 <Path as PartialEq>::eq(self, other)
2941 #[stable(feature = "partialeq_path", since = "1.6.0")]
2942 impl<'a, 'b> PartialEq<$lhs> for $rhs {
2944 fn eq(&self, other: &$lhs) -> bool {
2945 <Path as PartialEq>::eq(self, other)
2949 #[stable(feature = "cmp_path", since = "1.8.0")]
2950 impl<'a, 'b> PartialOrd<$rhs> for $lhs {
2952 fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
2953 <Path as PartialOrd>::partial_cmp(self, other)
2957 #[stable(feature = "cmp_path", since = "1.8.0")]
2958 impl<'a, 'b> PartialOrd<$lhs> for $rhs {
2960 fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
2961 <Path as PartialOrd>::partial_cmp(self, other)
2967 impl_cmp!(PathBuf, Path);
2968 impl_cmp!(PathBuf, &'a Path);
2969 impl_cmp!(Cow<'a, Path>, Path);
2970 impl_cmp!(Cow<'a, Path>, &'b Path);
2971 impl_cmp!(Cow<'a, Path>, PathBuf);
2973 macro_rules! impl_cmp_os_str {
2974 ($lhs:ty, $rhs: ty) => {
2975 #[stable(feature = "cmp_path", since = "1.8.0")]
2976 impl<'a, 'b> PartialEq<$rhs> for $lhs {
2978 fn eq(&self, other: &$rhs) -> bool {
2979 <Path as PartialEq>::eq(self, other.as_ref())
2983 #[stable(feature = "cmp_path", since = "1.8.0")]
2984 impl<'a, 'b> PartialEq<$lhs> for $rhs {
2986 fn eq(&self, other: &$lhs) -> bool {
2987 <Path as PartialEq>::eq(self.as_ref(), other)
2991 #[stable(feature = "cmp_path", since = "1.8.0")]
2992 impl<'a, 'b> PartialOrd<$rhs> for $lhs {
2994 fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
2995 <Path as PartialOrd>::partial_cmp(self, other.as_ref())
2999 #[stable(feature = "cmp_path", since = "1.8.0")]
3000 impl<'a, 'b> PartialOrd<$lhs> for $rhs {
3002 fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
3003 <Path as PartialOrd>::partial_cmp(self.as_ref(), other)
3009 impl_cmp_os_str!(PathBuf, OsStr);
3010 impl_cmp_os_str!(PathBuf, &'a OsStr);
3011 impl_cmp_os_str!(PathBuf, Cow<'a, OsStr>);
3012 impl_cmp_os_str!(PathBuf, OsString);
3013 impl_cmp_os_str!(Path, OsStr);
3014 impl_cmp_os_str!(Path, &'a OsStr);
3015 impl_cmp_os_str!(Path, Cow<'a, OsStr>);
3016 impl_cmp_os_str!(Path, OsString);
3017 impl_cmp_os_str!(&'a Path, OsStr);
3018 impl_cmp_os_str!(&'a Path, Cow<'b, OsStr>);
3019 impl_cmp_os_str!(&'a Path, OsString);
3020 impl_cmp_os_str!(Cow<'a, Path>, OsStr);
3021 impl_cmp_os_str!(Cow<'a, Path>, &'b OsStr);
3022 impl_cmp_os_str!(Cow<'a, Path>, OsString);
3024 #[stable(since = "1.7.0", feature = "strip_prefix")]
3025 impl fmt::Display for StripPrefixError {
3026 #[allow(deprecated, deprecated_in_future)]
3027 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
3028 self.description().fmt(f)
3032 #[stable(since = "1.7.0", feature = "strip_prefix")]
3033 impl Error for StripPrefixError {
3034 #[allow(deprecated)]
3035 fn description(&self) -> &str {