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Diffstat (limited to 'library/std/src/path.rs')
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diff --git a/library/std/src/path.rs b/library/std/src/path.rs new file mode 100644 index 000000000..5dfeb517a --- /dev/null +++ b/library/std/src/path.rs @@ -0,0 +1,3259 @@ +//! Cross-platform path manipulation. +//! +//! This module provides two types, [`PathBuf`] and [`Path`] (akin to [`String`] +//! and [`str`]), for working with paths abstractly. These types are thin wrappers +//! around [`OsString`] and [`OsStr`] respectively, meaning that they work directly +//! on strings according to the local platform's path syntax. +//! +//! Paths can be parsed into [`Component`]s by iterating over the structure +//! returned by the [`components`] method on [`Path`]. [`Component`]s roughly +//! correspond to the substrings between path separators (`/` or `\`). You can +//! reconstruct an equivalent path from components with the [`push`] method on +//! [`PathBuf`]; note that the paths may differ syntactically by the +//! normalization described in the documentation for the [`components`] method. +//! +//! ## Case sensitivity +//! +//! Unless otherwise indicated path methods that do not access the filesystem, +//! such as [`Path::starts_with`] and [`Path::ends_with`], are case sensitive no +//! matter the platform or filesystem. An exception to this is made for Windows +//! drive letters. +//! +//! ## Simple usage +//! +//! Path manipulation includes both parsing components from slices and building +//! new owned paths. +//! +//! To parse a path, you can create a [`Path`] slice from a [`str`] +//! slice and start asking questions: +//! +//! ``` +//! use std::path::Path; +//! use std::ffi::OsStr; +//! +//! let path = Path::new("/tmp/foo/bar.txt"); +//! +//! let parent = path.parent(); +//! assert_eq!(parent, Some(Path::new("/tmp/foo"))); +//! +//! let file_stem = path.file_stem(); +//! assert_eq!(file_stem, Some(OsStr::new("bar"))); +//! +//! let extension = path.extension(); +//! assert_eq!(extension, Some(OsStr::new("txt"))); +//! ``` +//! +//! To build or modify paths, use [`PathBuf`]: +//! +//! ``` +//! use std::path::PathBuf; +//! +//! // This way works... +//! let mut path = PathBuf::from("c:\\"); +//! +//! path.push("windows"); +//! path.push("system32"); +//! +//! path.set_extension("dll"); +//! +//! // ... but push is best used if you don't know everything up +//! // front. If you do, this way is better: +//! let path: PathBuf = ["c:\\", "windows", "system32.dll"].iter().collect(); +//! ``` +//! +//! [`components`]: Path::components +//! [`push`]: PathBuf::push + +#![stable(feature = "rust1", since = "1.0.0")] +#![deny(unsafe_op_in_unsafe_fn)] + +#[cfg(test)] +mod tests; + +use crate::borrow::{Borrow, Cow}; +use crate::cmp; +use crate::collections::TryReserveError; +use crate::error::Error; +use crate::fmt; +use crate::fs; +use crate::hash::{Hash, Hasher}; +use crate::io; +use crate::iter::{self, FusedIterator}; +use crate::ops::{self, Deref}; +use crate::rc::Rc; +use crate::str::FromStr; +use crate::sync::Arc; + +use crate::ffi::{OsStr, OsString}; +use crate::sys; +use crate::sys::path::{is_sep_byte, is_verbatim_sep, parse_prefix, MAIN_SEP_STR}; + +//////////////////////////////////////////////////////////////////////////////// +// GENERAL NOTES +//////////////////////////////////////////////////////////////////////////////// +// +// Parsing in this module is done by directly transmuting OsStr to [u8] slices, +// taking advantage of the fact that OsStr always encodes ASCII characters +// as-is. Eventually, this transmutation should be replaced by direct uses of +// OsStr APIs for parsing, but it will take a while for those to become +// available. + +//////////////////////////////////////////////////////////////////////////////// +// Windows Prefixes +//////////////////////////////////////////////////////////////////////////////// + +/// Windows path prefixes, e.g., `C:` or `\\server\share`. +/// +/// Windows uses a variety of path prefix styles, including references to drive +/// volumes (like `C:`), network shared folders (like `\\server\share`), and +/// others. In addition, some path prefixes are "verbatim" (i.e., prefixed with +/// `\\?\`), in which case `/` is *not* treated as a separator and essentially +/// no normalization is performed. +/// +/// # Examples +/// +/// ``` +/// use std::path::{Component, Path, Prefix}; +/// use std::path::Prefix::*; +/// use std::ffi::OsStr; +/// +/// fn get_path_prefix(s: &str) -> Prefix { +/// let path = Path::new(s); +/// match path.components().next().unwrap() { +/// Component::Prefix(prefix_component) => prefix_component.kind(), +/// _ => panic!(), +/// } +/// } +/// +/// # if cfg!(windows) { +/// assert_eq!(Verbatim(OsStr::new("pictures")), +/// get_path_prefix(r"\\?\pictures\kittens")); +/// assert_eq!(VerbatimUNC(OsStr::new("server"), OsStr::new("share")), +/// get_path_prefix(r"\\?\UNC\server\share")); +/// assert_eq!(VerbatimDisk(b'C'), get_path_prefix(r"\\?\c:\")); +/// assert_eq!(DeviceNS(OsStr::new("BrainInterface")), +/// get_path_prefix(r"\\.\BrainInterface")); +/// assert_eq!(UNC(OsStr::new("server"), OsStr::new("share")), +/// get_path_prefix(r"\\server\share")); +/// assert_eq!(Disk(b'C'), get_path_prefix(r"C:\Users\Rust\Pictures\Ferris")); +/// # } +/// ``` +#[derive(Copy, Clone, Debug, Hash, PartialOrd, Ord, PartialEq, Eq)] +#[stable(feature = "rust1", since = "1.0.0")] +pub enum Prefix<'a> { + /// Verbatim prefix, e.g., `\\?\cat_pics`. + /// + /// Verbatim prefixes consist of `\\?\` immediately followed by the given + /// component. + #[stable(feature = "rust1", since = "1.0.0")] + Verbatim(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr), + + /// Verbatim prefix using Windows' _**U**niform **N**aming **C**onvention_, + /// e.g., `\\?\UNC\server\share`. + /// + /// Verbatim UNC prefixes consist of `\\?\UNC\` immediately followed by the + /// server's hostname and a share name. + #[stable(feature = "rust1", since = "1.0.0")] + VerbatimUNC( + #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr, + #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr, + ), + + /// Verbatim disk prefix, e.g., `\\?\C:`. + /// + /// Verbatim disk prefixes consist of `\\?\` immediately followed by the + /// drive letter and `:`. + #[stable(feature = "rust1", since = "1.0.0")] + VerbatimDisk(#[stable(feature = "rust1", since = "1.0.0")] u8), + + /// Device namespace prefix, e.g., `\\.\COM42`. + /// + /// Device namespace prefixes consist of `\\.\` (possibly using `/` + /// instead of `\`), immediately followed by the device name. + #[stable(feature = "rust1", since = "1.0.0")] + DeviceNS(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr), + + /// Prefix using Windows' _**U**niform **N**aming **C**onvention_, e.g. + /// `\\server\share`. + /// + /// UNC prefixes consist of the server's hostname and a share name. + #[stable(feature = "rust1", since = "1.0.0")] + UNC( + #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr, + #[stable(feature = "rust1", since = "1.0.0")] &'a OsStr, + ), + + /// Prefix `C:` for the given disk drive. + #[stable(feature = "rust1", since = "1.0.0")] + Disk(#[stable(feature = "rust1", since = "1.0.0")] u8), +} + +impl<'a> Prefix<'a> { + #[inline] + fn len(&self) -> usize { + use self::Prefix::*; + fn os_str_len(s: &OsStr) -> usize { + s.bytes().len() + } + match *self { + Verbatim(x) => 4 + os_str_len(x), + VerbatimUNC(x, y) => { + 8 + os_str_len(x) + if os_str_len(y) > 0 { 1 + os_str_len(y) } else { 0 } + } + VerbatimDisk(_) => 6, + UNC(x, y) => 2 + os_str_len(x) + if os_str_len(y) > 0 { 1 + os_str_len(y) } else { 0 }, + DeviceNS(x) => 4 + os_str_len(x), + Disk(_) => 2, + } + } + + /// Determines if the prefix is verbatim, i.e., begins with `\\?\`. + /// + /// # Examples + /// + /// ``` + /// use std::path::Prefix::*; + /// use std::ffi::OsStr; + /// + /// assert!(Verbatim(OsStr::new("pictures")).is_verbatim()); + /// assert!(VerbatimUNC(OsStr::new("server"), OsStr::new("share")).is_verbatim()); + /// assert!(VerbatimDisk(b'C').is_verbatim()); + /// assert!(!DeviceNS(OsStr::new("BrainInterface")).is_verbatim()); + /// assert!(!UNC(OsStr::new("server"), OsStr::new("share")).is_verbatim()); + /// assert!(!Disk(b'C').is_verbatim()); + /// ``` + #[inline] + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn is_verbatim(&self) -> bool { + use self::Prefix::*; + matches!(*self, Verbatim(_) | VerbatimDisk(_) | VerbatimUNC(..)) + } + + #[inline] + fn is_drive(&self) -> bool { + matches!(*self, Prefix::Disk(_)) + } + + #[inline] + fn has_implicit_root(&self) -> bool { + !self.is_drive() + } +} + +//////////////////////////////////////////////////////////////////////////////// +// Exposed parsing helpers +//////////////////////////////////////////////////////////////////////////////// + +/// Determines whether the character is one of the permitted path +/// separators for the current platform. +/// +/// # Examples +/// +/// ``` +/// use std::path; +/// +/// assert!(path::is_separator('/')); // '/' works for both Unix and Windows +/// assert!(!path::is_separator('❤')); +/// ``` +#[must_use] +#[stable(feature = "rust1", since = "1.0.0")] +pub fn is_separator(c: char) -> bool { + c.is_ascii() && is_sep_byte(c as u8) +} + +/// The primary separator of path components for the current platform. +/// +/// For example, `/` on Unix and `\` on Windows. +#[stable(feature = "rust1", since = "1.0.0")] +pub const MAIN_SEPARATOR: char = crate::sys::path::MAIN_SEP; + +/// The primary separator of path components for the current platform. +/// +/// For example, `/` on Unix and `\` on Windows. +#[unstable(feature = "main_separator_str", issue = "94071")] +pub const MAIN_SEPARATOR_STR: &str = crate::sys::path::MAIN_SEP_STR; + +//////////////////////////////////////////////////////////////////////////////// +// Misc helpers +//////////////////////////////////////////////////////////////////////////////// + +// Iterate through `iter` while it matches `prefix`; return `None` if `prefix` +// is not a prefix of `iter`, otherwise return `Some(iter_after_prefix)` giving +// `iter` after having exhausted `prefix`. +fn iter_after<'a, 'b, I, J>(mut iter: I, mut prefix: J) -> Option<I> +where + I: Iterator<Item = Component<'a>> + Clone, + J: Iterator<Item = Component<'b>>, +{ + loop { + let mut iter_next = iter.clone(); + match (iter_next.next(), prefix.next()) { + (Some(ref x), Some(ref y)) if x == y => (), + (Some(_), Some(_)) => return None, + (Some(_), None) => return Some(iter), + (None, None) => return Some(iter), + (None, Some(_)) => return None, + } + iter = iter_next; + } +} + +unsafe fn u8_slice_as_os_str(s: &[u8]) -> &OsStr { + // SAFETY: See note at the top of this module to understand why this and + // `OsStr::bytes` are used: + // + // This casts are safe as OsStr is internally a wrapper around [u8] on all + // platforms. + // + // Note that currently this relies on the special knowledge that libstd has; + // these types are single-element structs but are not marked + // repr(transparent) or repr(C) which would make these casts not allowable + // outside std. + unsafe { &*(s as *const [u8] as *const OsStr) } +} + +// Detect scheme on Redox +fn has_redox_scheme(s: &[u8]) -> bool { + cfg!(target_os = "redox") && s.contains(&b':') +} + +//////////////////////////////////////////////////////////////////////////////// +// Cross-platform, iterator-independent parsing +//////////////////////////////////////////////////////////////////////////////// + +/// Says whether the first byte after the prefix is a separator. +fn has_physical_root(s: &[u8], prefix: Option<Prefix<'_>>) -> bool { + let path = if let Some(p) = prefix { &s[p.len()..] } else { s }; + !path.is_empty() && is_sep_byte(path[0]) +} + +// basic workhorse for splitting stem and extension +fn rsplit_file_at_dot(file: &OsStr) -> (Option<&OsStr>, Option<&OsStr>) { + if file.bytes() == b".." { + return (Some(file), None); + } + + // The unsafety here stems from converting between &OsStr and &[u8] + // and back. This is safe to do because (1) we only look at ASCII + // contents of the encoding and (2) new &OsStr values are produced + // only from ASCII-bounded slices of existing &OsStr values. + let mut iter = file.bytes().rsplitn(2, |b| *b == b'.'); + let after = iter.next(); + let before = iter.next(); + if before == Some(b"") { + (Some(file), None) + } else { + unsafe { (before.map(|s| u8_slice_as_os_str(s)), after.map(|s| u8_slice_as_os_str(s))) } + } +} + +fn split_file_at_dot(file: &OsStr) -> (&OsStr, Option<&OsStr>) { + let slice = file.bytes(); + if slice == b".." { + return (file, None); + } + + // The unsafety here stems from converting between &OsStr and &[u8] + // and back. This is safe to do because (1) we only look at ASCII + // contents of the encoding and (2) new &OsStr values are produced + // only from ASCII-bounded slices of existing &OsStr values. + let i = match slice[1..].iter().position(|b| *b == b'.') { + Some(i) => i + 1, + None => return (file, None), + }; + let before = &slice[..i]; + let after = &slice[i + 1..]; + unsafe { (u8_slice_as_os_str(before), Some(u8_slice_as_os_str(after))) } +} + +//////////////////////////////////////////////////////////////////////////////// +// The core iterators +//////////////////////////////////////////////////////////////////////////////// + +/// Component parsing works by a double-ended state machine; the cursors at the +/// front and back of the path each keep track of what parts of the path have +/// been consumed so far. +/// +/// Going front to back, a path is made up of a prefix, a starting +/// directory component, and a body (of normal components) +#[derive(Copy, Clone, PartialEq, PartialOrd, Debug)] +enum State { + Prefix = 0, // c: + StartDir = 1, // / or . or nothing + Body = 2, // foo/bar/baz + Done = 3, +} + +/// A structure wrapping a Windows path prefix as well as its unparsed string +/// representation. +/// +/// In addition to the parsed [`Prefix`] information returned by [`kind`], +/// `PrefixComponent` also holds the raw and unparsed [`OsStr`] slice, +/// returned by [`as_os_str`]. +/// +/// Instances of this `struct` can be obtained by matching against the +/// [`Prefix` variant] on [`Component`]. +/// +/// Does not occur on Unix. +/// +/// # Examples +/// +/// ``` +/// # if cfg!(windows) { +/// use std::path::{Component, Path, Prefix}; +/// use std::ffi::OsStr; +/// +/// let path = Path::new(r"c:\you\later\"); +/// match path.components().next().unwrap() { +/// Component::Prefix(prefix_component) => { +/// assert_eq!(Prefix::Disk(b'C'), prefix_component.kind()); +/// assert_eq!(OsStr::new("c:"), prefix_component.as_os_str()); +/// } +/// _ => unreachable!(), +/// } +/// # } +/// ``` +/// +/// [`as_os_str`]: PrefixComponent::as_os_str +/// [`kind`]: PrefixComponent::kind +/// [`Prefix` variant]: Component::Prefix +#[stable(feature = "rust1", since = "1.0.0")] +#[derive(Copy, Clone, Eq, Debug)] +pub struct PrefixComponent<'a> { + /// The prefix as an unparsed `OsStr` slice. + raw: &'a OsStr, + + /// The parsed prefix data. + parsed: Prefix<'a>, +} + +impl<'a> PrefixComponent<'a> { + /// Returns the parsed prefix data. + /// + /// See [`Prefix`]'s documentation for more information on the different + /// kinds of prefixes. + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn kind(&self) -> Prefix<'a> { + self.parsed + } + + /// Returns the raw [`OsStr`] slice for this prefix. + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn as_os_str(&self) -> &'a OsStr { + self.raw + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> cmp::PartialEq for PrefixComponent<'a> { + #[inline] + fn eq(&self, other: &PrefixComponent<'a>) -> bool { + cmp::PartialEq::eq(&self.parsed, &other.parsed) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> cmp::PartialOrd for PrefixComponent<'a> { + #[inline] + fn partial_cmp(&self, other: &PrefixComponent<'a>) -> Option<cmp::Ordering> { + cmp::PartialOrd::partial_cmp(&self.parsed, &other.parsed) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Ord for PrefixComponent<'_> { + #[inline] + fn cmp(&self, other: &Self) -> cmp::Ordering { + cmp::Ord::cmp(&self.parsed, &other.parsed) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Hash for PrefixComponent<'_> { + fn hash<H: Hasher>(&self, h: &mut H) { + self.parsed.hash(h); + } +} + +/// A single component of a path. +/// +/// A `Component` roughly corresponds to a substring between path separators +/// (`/` or `\`). +/// +/// This `enum` is created by iterating over [`Components`], which in turn is +/// created by the [`components`](Path::components) method on [`Path`]. +/// +/// # Examples +/// +/// ```rust +/// use std::path::{Component, Path}; +/// +/// let path = Path::new("/tmp/foo/bar.txt"); +/// let components = path.components().collect::<Vec<_>>(); +/// assert_eq!(&components, &[ +/// Component::RootDir, +/// Component::Normal("tmp".as_ref()), +/// Component::Normal("foo".as_ref()), +/// Component::Normal("bar.txt".as_ref()), +/// ]); +/// ``` +#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] +#[stable(feature = "rust1", since = "1.0.0")] +pub enum Component<'a> { + /// A Windows path prefix, e.g., `C:` or `\\server\share`. + /// + /// There is a large variety of prefix types, see [`Prefix`]'s documentation + /// for more. + /// + /// Does not occur on Unix. + #[stable(feature = "rust1", since = "1.0.0")] + Prefix(#[stable(feature = "rust1", since = "1.0.0")] PrefixComponent<'a>), + + /// The root directory component, appears after any prefix and before anything else. + /// + /// It represents a separator that designates that a path starts from root. + #[stable(feature = "rust1", since = "1.0.0")] + RootDir, + + /// A reference to the current directory, i.e., `.`. + #[stable(feature = "rust1", since = "1.0.0")] + CurDir, + + /// A reference to the parent directory, i.e., `..`. + #[stable(feature = "rust1", since = "1.0.0")] + ParentDir, + + /// A normal component, e.g., `a` and `b` in `a/b`. + /// + /// This variant is the most common one, it represents references to files + /// or directories. + #[stable(feature = "rust1", since = "1.0.0")] + Normal(#[stable(feature = "rust1", since = "1.0.0")] &'a OsStr), +} + +impl<'a> Component<'a> { + /// Extracts the underlying [`OsStr`] slice. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("./tmp/foo/bar.txt"); + /// let components: Vec<_> = path.components().map(|comp| comp.as_os_str()).collect(); + /// assert_eq!(&components, &[".", "tmp", "foo", "bar.txt"]); + /// ``` + #[must_use = "`self` will be dropped if the result is not used"] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn as_os_str(self) -> &'a OsStr { + match self { + Component::Prefix(p) => p.as_os_str(), + Component::RootDir => OsStr::new(MAIN_SEP_STR), + Component::CurDir => OsStr::new("."), + Component::ParentDir => OsStr::new(".."), + Component::Normal(path) => path, + } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<OsStr> for Component<'_> { + #[inline] + fn as_ref(&self) -> &OsStr { + self.as_os_str() + } +} + +#[stable(feature = "path_component_asref", since = "1.25.0")] +impl AsRef<Path> for Component<'_> { + #[inline] + fn as_ref(&self) -> &Path { + self.as_os_str().as_ref() + } +} + +/// An iterator over the [`Component`]s of a [`Path`]. +/// +/// This `struct` is created by the [`components`] method on [`Path`]. +/// See its documentation for more. +/// +/// # Examples +/// +/// ``` +/// use std::path::Path; +/// +/// let path = Path::new("/tmp/foo/bar.txt"); +/// +/// for component in path.components() { +/// println!("{component:?}"); +/// } +/// ``` +/// +/// [`components`]: Path::components +#[derive(Clone)] +#[must_use = "iterators are lazy and do nothing unless consumed"] +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Components<'a> { + // The path left to parse components from + path: &'a [u8], + + // The prefix as it was originally parsed, if any + prefix: Option<Prefix<'a>>, + + // true if path *physically* has a root separator; for most Windows + // prefixes, it may have a "logical" root separator for the purposes of + // normalization, e.g., \\server\share == \\server\share\. + has_physical_root: bool, + + // The iterator is double-ended, and these two states keep track of what has + // been produced from either end + front: State, + back: State, +} + +/// An iterator over the [`Component`]s of a [`Path`], as [`OsStr`] slices. +/// +/// This `struct` is created by the [`iter`] method on [`Path`]. +/// See its documentation for more. +/// +/// [`iter`]: Path::iter +#[derive(Clone)] +#[must_use = "iterators are lazy and do nothing unless consumed"] +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Iter<'a> { + inner: Components<'a>, +} + +#[stable(feature = "path_components_debug", since = "1.13.0")] +impl fmt::Debug for Components<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + struct DebugHelper<'a>(&'a Path); + + impl fmt::Debug for DebugHelper<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.0.components()).finish() + } + } + + f.debug_tuple("Components").field(&DebugHelper(self.as_path())).finish() + } +} + +impl<'a> Components<'a> { + // how long is the prefix, if any? + #[inline] + fn prefix_len(&self) -> usize { + self.prefix.as_ref().map(Prefix::len).unwrap_or(0) + } + + #[inline] + fn prefix_verbatim(&self) -> bool { + self.prefix.as_ref().map(Prefix::is_verbatim).unwrap_or(false) + } + + /// how much of the prefix is left from the point of view of iteration? + #[inline] + fn prefix_remaining(&self) -> usize { + if self.front == State::Prefix { self.prefix_len() } else { 0 } + } + + // Given the iteration so far, how much of the pre-State::Body path is left? + #[inline] + fn len_before_body(&self) -> usize { + let root = if self.front <= State::StartDir && self.has_physical_root { 1 } else { 0 }; + let cur_dir = if self.front <= State::StartDir && self.include_cur_dir() { 1 } else { 0 }; + self.prefix_remaining() + root + cur_dir + } + + // is the iteration complete? + #[inline] + fn finished(&self) -> bool { + self.front == State::Done || self.back == State::Done || self.front > self.back + } + + #[inline] + fn is_sep_byte(&self, b: u8) -> bool { + if self.prefix_verbatim() { is_verbatim_sep(b) } else { is_sep_byte(b) } + } + + /// Extracts a slice corresponding to the portion of the path remaining for iteration. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let mut components = Path::new("/tmp/foo/bar.txt").components(); + /// components.next(); + /// components.next(); + /// + /// assert_eq!(Path::new("foo/bar.txt"), components.as_path()); + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn as_path(&self) -> &'a Path { + let mut comps = self.clone(); + if comps.front == State::Body { + comps.trim_left(); + } + if comps.back == State::Body { + comps.trim_right(); + } + unsafe { Path::from_u8_slice(comps.path) } + } + + /// Is the *original* path rooted? + fn has_root(&self) -> bool { + if self.has_physical_root { + return true; + } + if let Some(p) = self.prefix { + if p.has_implicit_root() { + return true; + } + } + false + } + + /// Should the normalized path include a leading . ? + fn include_cur_dir(&self) -> bool { + if self.has_root() { + return false; + } + let mut iter = self.path[self.prefix_remaining()..].iter(); + match (iter.next(), iter.next()) { + (Some(&b'.'), None) => true, + (Some(&b'.'), Some(&b)) => self.is_sep_byte(b), + _ => false, + } + } + + // parse a given byte sequence into the corresponding path component + fn parse_single_component<'b>(&self, comp: &'b [u8]) -> Option<Component<'b>> { + match comp { + b"." if self.prefix_verbatim() => Some(Component::CurDir), + b"." => None, // . components are normalized away, except at + // the beginning of a path, which is treated + // separately via `include_cur_dir` + b".." => Some(Component::ParentDir), + b"" => None, + _ => Some(Component::Normal(unsafe { u8_slice_as_os_str(comp) })), + } + } + + // parse a component from the left, saying how many bytes to consume to + // remove the component + fn parse_next_component(&self) -> (usize, Option<Component<'a>>) { + debug_assert!(self.front == State::Body); + let (extra, comp) = match self.path.iter().position(|b| self.is_sep_byte(*b)) { + None => (0, self.path), + Some(i) => (1, &self.path[..i]), + }; + (comp.len() + extra, self.parse_single_component(comp)) + } + + // parse a component from the right, saying how many bytes to consume to + // remove the component + fn parse_next_component_back(&self) -> (usize, Option<Component<'a>>) { + debug_assert!(self.back == State::Body); + let start = self.len_before_body(); + let (extra, comp) = match self.path[start..].iter().rposition(|b| self.is_sep_byte(*b)) { + None => (0, &self.path[start..]), + Some(i) => (1, &self.path[start + i + 1..]), + }; + (comp.len() + extra, self.parse_single_component(comp)) + } + + // trim away repeated separators (i.e., empty components) on the left + fn trim_left(&mut self) { + while !self.path.is_empty() { + let (size, comp) = self.parse_next_component(); + if comp.is_some() { + return; + } else { + self.path = &self.path[size..]; + } + } + } + + // trim away repeated separators (i.e., empty components) on the right + fn trim_right(&mut self) { + while self.path.len() > self.len_before_body() { + let (size, comp) = self.parse_next_component_back(); + if comp.is_some() { + return; + } else { + self.path = &self.path[..self.path.len() - size]; + } + } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for Components<'_> { + #[inline] + fn as_ref(&self) -> &Path { + self.as_path() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<OsStr> for Components<'_> { + #[inline] + fn as_ref(&self) -> &OsStr { + self.as_path().as_os_str() + } +} + +#[stable(feature = "path_iter_debug", since = "1.13.0")] +impl fmt::Debug for Iter<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + struct DebugHelper<'a>(&'a Path); + + impl fmt::Debug for DebugHelper<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.0.iter()).finish() + } + } + + f.debug_tuple("Iter").field(&DebugHelper(self.as_path())).finish() + } +} + +impl<'a> Iter<'a> { + /// Extracts a slice corresponding to the portion of the path remaining for iteration. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let mut iter = Path::new("/tmp/foo/bar.txt").iter(); + /// iter.next(); + /// iter.next(); + /// + /// assert_eq!(Path::new("foo/bar.txt"), iter.as_path()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn as_path(&self) -> &'a Path { + self.inner.as_path() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for Iter<'_> { + #[inline] + fn as_ref(&self) -> &Path { + self.as_path() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<OsStr> for Iter<'_> { + #[inline] + fn as_ref(&self) -> &OsStr { + self.as_path().as_os_str() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> Iterator for Iter<'a> { + type Item = &'a OsStr; + + #[inline] + fn next(&mut self) -> Option<&'a OsStr> { + self.inner.next().map(Component::as_os_str) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> DoubleEndedIterator for Iter<'a> { + #[inline] + fn next_back(&mut self) -> Option<&'a OsStr> { + self.inner.next_back().map(Component::as_os_str) + } +} + +#[stable(feature = "fused", since = "1.26.0")] +impl FusedIterator for Iter<'_> {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> Iterator for Components<'a> { + type Item = Component<'a>; + + fn next(&mut self) -> Option<Component<'a>> { + while !self.finished() { + match self.front { + State::Prefix if self.prefix_len() > 0 => { + self.front = State::StartDir; + debug_assert!(self.prefix_len() <= self.path.len()); + let raw = &self.path[..self.prefix_len()]; + self.path = &self.path[self.prefix_len()..]; + return Some(Component::Prefix(PrefixComponent { + raw: unsafe { u8_slice_as_os_str(raw) }, + parsed: self.prefix.unwrap(), + })); + } + State::Prefix => { + self.front = State::StartDir; + } + State::StartDir => { + self.front = State::Body; + if self.has_physical_root { + debug_assert!(!self.path.is_empty()); + self.path = &self.path[1..]; + return Some(Component::RootDir); + } else if let Some(p) = self.prefix { + if p.has_implicit_root() && !p.is_verbatim() { + return Some(Component::RootDir); + } + } else if self.include_cur_dir() { + debug_assert!(!self.path.is_empty()); + self.path = &self.path[1..]; + return Some(Component::CurDir); + } + } + State::Body if !self.path.is_empty() => { + let (size, comp) = self.parse_next_component(); + self.path = &self.path[size..]; + if comp.is_some() { + return comp; + } + } + State::Body => { + self.front = State::Done; + } + State::Done => unreachable!(), + } + } + None + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> DoubleEndedIterator for Components<'a> { + fn next_back(&mut self) -> Option<Component<'a>> { + while !self.finished() { + match self.back { + State::Body if self.path.len() > self.len_before_body() => { + let (size, comp) = self.parse_next_component_back(); + self.path = &self.path[..self.path.len() - size]; + if comp.is_some() { + return comp; + } + } + State::Body => { + self.back = State::StartDir; + } + State::StartDir => { + self.back = State::Prefix; + if self.has_physical_root { + self.path = &self.path[..self.path.len() - 1]; + return Some(Component::RootDir); + } else if let Some(p) = self.prefix { + if p.has_implicit_root() && !p.is_verbatim() { + return Some(Component::RootDir); + } + } else if self.include_cur_dir() { + self.path = &self.path[..self.path.len() - 1]; + return Some(Component::CurDir); + } + } + State::Prefix if self.prefix_len() > 0 => { + self.back = State::Done; + return Some(Component::Prefix(PrefixComponent { + raw: unsafe { u8_slice_as_os_str(self.path) }, + parsed: self.prefix.unwrap(), + })); + } + State::Prefix => { + self.back = State::Done; + return None; + } + State::Done => unreachable!(), + } + } + None + } +} + +#[stable(feature = "fused", since = "1.26.0")] +impl FusedIterator for Components<'_> {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> cmp::PartialEq for Components<'a> { + #[inline] + fn eq(&self, other: &Components<'a>) -> bool { + let Components { path: _, front: _, back: _, has_physical_root: _, prefix: _ } = self; + + // Fast path for exact matches, e.g. for hashmap lookups. + // Don't explicitly compare the prefix or has_physical_root fields since they'll + // either be covered by the `path` buffer or are only relevant for `prefix_verbatim()`. + if self.path.len() == other.path.len() + && self.front == other.front + && self.back == State::Body + && other.back == State::Body + && self.prefix_verbatim() == other.prefix_verbatim() + { + // possible future improvement: this could bail out earlier if there were a + // reverse memcmp/bcmp comparing back to front + if self.path == other.path { + return true; + } + } + + // compare back to front since absolute paths often share long prefixes + Iterator::eq(self.clone().rev(), other.clone().rev()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Eq for Components<'_> {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> cmp::PartialOrd for Components<'a> { + #[inline] + fn partial_cmp(&self, other: &Components<'a>) -> Option<cmp::Ordering> { + Some(compare_components(self.clone(), other.clone())) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Ord for Components<'_> { + #[inline] + fn cmp(&self, other: &Self) -> cmp::Ordering { + compare_components(self.clone(), other.clone()) + } +} + +fn compare_components(mut left: Components<'_>, mut right: Components<'_>) -> cmp::Ordering { + // Fast path for long shared prefixes + // + // - compare raw bytes to find first mismatch + // - backtrack to find separator before mismatch to avoid ambiguous parsings of '.' or '..' characters + // - if found update state to only do a component-wise comparison on the remainder, + // otherwise do it on the full path + // + // The fast path isn't taken for paths with a PrefixComponent to avoid backtracking into + // the middle of one + if left.prefix.is_none() && right.prefix.is_none() && left.front == right.front { + // possible future improvement: a [u8]::first_mismatch simd implementation + let first_difference = match left.path.iter().zip(right.path).position(|(&a, &b)| a != b) { + None if left.path.len() == right.path.len() => return cmp::Ordering::Equal, + None => left.path.len().min(right.path.len()), + Some(diff) => diff, + }; + + if let Some(previous_sep) = + left.path[..first_difference].iter().rposition(|&b| left.is_sep_byte(b)) + { + let mismatched_component_start = previous_sep + 1; + left.path = &left.path[mismatched_component_start..]; + left.front = State::Body; + right.path = &right.path[mismatched_component_start..]; + right.front = State::Body; + } + } + + Iterator::cmp(left, right) +} + +/// An iterator over [`Path`] and its ancestors. +/// +/// This `struct` is created by the [`ancestors`] method on [`Path`]. +/// See its documentation for more. +/// +/// # Examples +/// +/// ``` +/// use std::path::Path; +/// +/// let path = Path::new("/foo/bar"); +/// +/// for ancestor in path.ancestors() { +/// println!("{}", ancestor.display()); +/// } +/// ``` +/// +/// [`ancestors`]: Path::ancestors +#[derive(Copy, Clone, Debug)] +#[must_use = "iterators are lazy and do nothing unless consumed"] +#[stable(feature = "path_ancestors", since = "1.28.0")] +pub struct Ancestors<'a> { + next: Option<&'a Path>, +} + +#[stable(feature = "path_ancestors", since = "1.28.0")] +impl<'a> Iterator for Ancestors<'a> { + type Item = &'a Path; + + #[inline] + fn next(&mut self) -> Option<Self::Item> { + let next = self.next; + self.next = next.and_then(Path::parent); + next + } +} + +#[stable(feature = "path_ancestors", since = "1.28.0")] +impl FusedIterator for Ancestors<'_> {} + +//////////////////////////////////////////////////////////////////////////////// +// Basic types and traits +//////////////////////////////////////////////////////////////////////////////// + +/// An owned, mutable path (akin to [`String`]). +/// +/// This type provides methods like [`push`] and [`set_extension`] that mutate +/// the path in place. It also implements [`Deref`] to [`Path`], meaning that +/// all methods on [`Path`] slices are available on `PathBuf` values as well. +/// +/// [`push`]: PathBuf::push +/// [`set_extension`]: PathBuf::set_extension +/// +/// More details about the overall approach can be found in +/// the [module documentation](self). +/// +/// # Examples +/// +/// You can use [`push`] to build up a `PathBuf` from +/// components: +/// +/// ``` +/// use std::path::PathBuf; +/// +/// let mut path = PathBuf::new(); +/// +/// path.push(r"C:\"); +/// path.push("windows"); +/// path.push("system32"); +/// +/// path.set_extension("dll"); +/// ``` +/// +/// However, [`push`] is best used for dynamic situations. This is a better way +/// to do this when you know all of the components ahead of time: +/// +/// ``` +/// use std::path::PathBuf; +/// +/// let path: PathBuf = [r"C:\", "windows", "system32.dll"].iter().collect(); +/// ``` +/// +/// We can still do better than this! Since these are all strings, we can use +/// `From::from`: +/// +/// ``` +/// use std::path::PathBuf; +/// +/// let path = PathBuf::from(r"C:\windows\system32.dll"); +/// ``` +/// +/// Which method works best depends on what kind of situation you're in. +#[cfg_attr(not(test), rustc_diagnostic_item = "PathBuf")] +#[stable(feature = "rust1", since = "1.0.0")] +// FIXME: +// `PathBuf::as_mut_vec` current implementation relies +// on `PathBuf` being layout-compatible with `Vec<u8>`. +// When attribute privacy is implemented, `PathBuf` should be annotated as `#[repr(transparent)]`. +// Anyway, `PathBuf` representation and layout are considered implementation detail, are +// not documented and must not be relied upon. +pub struct PathBuf { + inner: OsString, +} + +impl PathBuf { + #[inline] + fn as_mut_vec(&mut self) -> &mut Vec<u8> { + unsafe { &mut *(self as *mut PathBuf as *mut Vec<u8>) } + } + + /// Allocates an empty `PathBuf`. + /// + /// # Examples + /// + /// ``` + /// use std::path::PathBuf; + /// + /// let path = PathBuf::new(); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn new() -> PathBuf { + PathBuf { inner: OsString::new() } + } + + /// Creates a new `PathBuf` with a given capacity used to create the + /// internal [`OsString`]. See [`with_capacity`] defined on [`OsString`]. + /// + /// # Examples + /// + /// ``` + /// use std::path::PathBuf; + /// + /// let mut path = PathBuf::with_capacity(10); + /// let capacity = path.capacity(); + /// + /// // This push is done without reallocating + /// path.push(r"C:\"); + /// + /// assert_eq!(capacity, path.capacity()); + /// ``` + /// + /// [`with_capacity`]: OsString::with_capacity + #[stable(feature = "path_buf_capacity", since = "1.44.0")] + #[must_use] + #[inline] + pub fn with_capacity(capacity: usize) -> PathBuf { + PathBuf { inner: OsString::with_capacity(capacity) } + } + + /// Coerces to a [`Path`] slice. + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// let p = PathBuf::from("/test"); + /// assert_eq!(Path::new("/test"), p.as_path()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn as_path(&self) -> &Path { + self + } + + /// Extends `self` with `path`. + /// + /// If `path` is absolute, it replaces the current path. + /// + /// On Windows: + /// + /// * if `path` has a root but no prefix (e.g., `\windows`), it + /// replaces everything except for the prefix (if any) of `self`. + /// * if `path` has a prefix but no root, it replaces `self`. + /// * if `self` has a verbatim prefix (e.g. `\\?\C:\windows`) + /// and `path` is not empty, the new path is normalized: all references + /// to `.` and `..` are removed. + /// + /// # Examples + /// + /// Pushing a relative path extends the existing path: + /// + /// ``` + /// use std::path::PathBuf; + /// + /// let mut path = PathBuf::from("/tmp"); + /// path.push("file.bk"); + /// assert_eq!(path, PathBuf::from("/tmp/file.bk")); + /// ``` + /// + /// Pushing an absolute path replaces the existing path: + /// + /// ``` + /// use std::path::PathBuf; + /// + /// let mut path = PathBuf::from("/tmp"); + /// path.push("/etc"); + /// assert_eq!(path, PathBuf::from("/etc")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn push<P: AsRef<Path>>(&mut self, path: P) { + self._push(path.as_ref()) + } + + fn _push(&mut self, path: &Path) { + // in general, a separator is needed if the rightmost byte is not a separator + let mut need_sep = self.as_mut_vec().last().map(|c| !is_sep_byte(*c)).unwrap_or(false); + + // in the special case of `C:` on Windows, do *not* add a separator + let comps = self.components(); + + if comps.prefix_len() > 0 + && comps.prefix_len() == comps.path.len() + && comps.prefix.unwrap().is_drive() + { + need_sep = false + } + + // absolute `path` replaces `self` + if path.is_absolute() || path.prefix().is_some() { + self.as_mut_vec().truncate(0); + + // verbatim paths need . and .. removed + } else if comps.prefix_verbatim() && !path.inner.is_empty() { + let mut buf: Vec<_> = comps.collect(); + for c in path.components() { + match c { + Component::RootDir => { + buf.truncate(1); + buf.push(c); + } + Component::CurDir => (), + Component::ParentDir => { + if let Some(Component::Normal(_)) = buf.last() { + buf.pop(); + } + } + _ => buf.push(c), + } + } + + let mut res = OsString::new(); + let mut need_sep = false; + + for c in buf { + if need_sep && c != Component::RootDir { + res.push(MAIN_SEP_STR); + } + res.push(c.as_os_str()); + + need_sep = match c { + Component::RootDir => false, + Component::Prefix(prefix) => { + !prefix.parsed.is_drive() && prefix.parsed.len() > 0 + } + _ => true, + } + } + + self.inner = res; + return; + + // `path` has a root but no prefix, e.g., `\windows` (Windows only) + } else if path.has_root() { + let prefix_len = self.components().prefix_remaining(); + self.as_mut_vec().truncate(prefix_len); + + // `path` is a pure relative path + } else if need_sep { + self.inner.push(MAIN_SEP_STR); + } + + self.inner.push(path); + } + + /// Truncates `self` to [`self.parent`]. + /// + /// Returns `false` and does nothing if [`self.parent`] is [`None`]. + /// Otherwise, returns `true`. + /// + /// [`self.parent`]: Path::parent + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// let mut p = PathBuf::from("/spirited/away.rs"); + /// + /// p.pop(); + /// assert_eq!(Path::new("/spirited"), p); + /// p.pop(); + /// assert_eq!(Path::new("/"), p); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn pop(&mut self) -> bool { + match self.parent().map(|p| p.as_u8_slice().len()) { + Some(len) => { + self.as_mut_vec().truncate(len); + true + } + None => false, + } + } + + /// Updates [`self.file_name`] to `file_name`. + /// + /// If [`self.file_name`] was [`None`], this is equivalent to pushing + /// `file_name`. + /// + /// Otherwise it is equivalent to calling [`pop`] and then pushing + /// `file_name`. The new path will be a sibling of the original path. + /// (That is, it will have the same parent.) + /// + /// [`self.file_name`]: Path::file_name + /// [`pop`]: PathBuf::pop + /// + /// # Examples + /// + /// ``` + /// use std::path::PathBuf; + /// + /// let mut buf = PathBuf::from("/"); + /// assert!(buf.file_name() == None); + /// buf.set_file_name("bar"); + /// assert!(buf == PathBuf::from("/bar")); + /// assert!(buf.file_name().is_some()); + /// buf.set_file_name("baz.txt"); + /// assert!(buf == PathBuf::from("/baz.txt")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn set_file_name<S: AsRef<OsStr>>(&mut self, file_name: S) { + self._set_file_name(file_name.as_ref()) + } + + fn _set_file_name(&mut self, file_name: &OsStr) { + if self.file_name().is_some() { + let popped = self.pop(); + debug_assert!(popped); + } + self.push(file_name); + } + + /// Updates [`self.extension`] to `extension`. + /// + /// Returns `false` and does nothing if [`self.file_name`] is [`None`], + /// returns `true` and updates the extension otherwise. + /// + /// If [`self.extension`] is [`None`], the extension is added; otherwise + /// it is replaced. + /// + /// [`self.file_name`]: Path::file_name + /// [`self.extension`]: Path::extension + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// let mut p = PathBuf::from("/feel/the"); + /// + /// p.set_extension("force"); + /// assert_eq!(Path::new("/feel/the.force"), p.as_path()); + /// + /// p.set_extension("dark_side"); + /// assert_eq!(Path::new("/feel/the.dark_side"), p.as_path()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn set_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> bool { + self._set_extension(extension.as_ref()) + } + + fn _set_extension(&mut self, extension: &OsStr) -> bool { + let file_stem = match self.file_stem() { + None => return false, + Some(f) => f.bytes(), + }; + + // truncate until right after the file stem + let end_file_stem = file_stem[file_stem.len()..].as_ptr().addr(); + let start = self.inner.bytes().as_ptr().addr(); + let v = self.as_mut_vec(); + v.truncate(end_file_stem.wrapping_sub(start)); + + // add the new extension, if any + let new = extension.bytes(); + if !new.is_empty() { + v.reserve_exact(new.len() + 1); + v.push(b'.'); + v.extend_from_slice(new); + } + + true + } + + /// Consumes the `PathBuf`, yielding its internal [`OsString`] storage. + /// + /// # Examples + /// + /// ``` + /// use std::path::PathBuf; + /// + /// let p = PathBuf::from("/the/head"); + /// let os_str = p.into_os_string(); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use = "`self` will be dropped if the result is not used"] + #[inline] + pub fn into_os_string(self) -> OsString { + self.inner + } + + /// Converts this `PathBuf` into a [boxed](Box) [`Path`]. + #[stable(feature = "into_boxed_path", since = "1.20.0")] + #[must_use = "`self` will be dropped if the result is not used"] + #[inline] + pub fn into_boxed_path(self) -> Box<Path> { + let rw = Box::into_raw(self.inner.into_boxed_os_str()) as *mut Path; + unsafe { Box::from_raw(rw) } + } + + /// Invokes [`capacity`] on the underlying instance of [`OsString`]. + /// + /// [`capacity`]: OsString::capacity + #[stable(feature = "path_buf_capacity", since = "1.44.0")] + #[must_use] + #[inline] + pub fn capacity(&self) -> usize { + self.inner.capacity() + } + + /// Invokes [`clear`] on the underlying instance of [`OsString`]. + /// + /// [`clear`]: OsString::clear + #[stable(feature = "path_buf_capacity", since = "1.44.0")] + #[inline] + pub fn clear(&mut self) { + self.inner.clear() + } + + /// Invokes [`reserve`] on the underlying instance of [`OsString`]. + /// + /// [`reserve`]: OsString::reserve + #[stable(feature = "path_buf_capacity", since = "1.44.0")] + #[inline] + pub fn reserve(&mut self, additional: usize) { + self.inner.reserve(additional) + } + + /// Invokes [`try_reserve`] on the underlying instance of [`OsString`]. + /// + /// [`try_reserve`]: OsString::try_reserve + #[stable(feature = "try_reserve_2", since = "1.63.0")] + #[inline] + pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> { + self.inner.try_reserve(additional) + } + + /// Invokes [`reserve_exact`] on the underlying instance of [`OsString`]. + /// + /// [`reserve_exact`]: OsString::reserve_exact + #[stable(feature = "path_buf_capacity", since = "1.44.0")] + #[inline] + pub fn reserve_exact(&mut self, additional: usize) { + self.inner.reserve_exact(additional) + } + + /// Invokes [`try_reserve_exact`] on the underlying instance of [`OsString`]. + /// + /// [`try_reserve_exact`]: OsString::try_reserve_exact + #[stable(feature = "try_reserve_2", since = "1.63.0")] + #[inline] + pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError> { + self.inner.try_reserve_exact(additional) + } + + /// Invokes [`shrink_to_fit`] on the underlying instance of [`OsString`]. + /// + /// [`shrink_to_fit`]: OsString::shrink_to_fit + #[stable(feature = "path_buf_capacity", since = "1.44.0")] + #[inline] + pub fn shrink_to_fit(&mut self) { + self.inner.shrink_to_fit() + } + + /// Invokes [`shrink_to`] on the underlying instance of [`OsString`]. + /// + /// [`shrink_to`]: OsString::shrink_to + #[stable(feature = "shrink_to", since = "1.56.0")] + #[inline] + pub fn shrink_to(&mut self, min_capacity: usize) { + self.inner.shrink_to(min_capacity) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Clone for PathBuf { + #[inline] + fn clone(&self) -> Self { + PathBuf { inner: self.inner.clone() } + } + + #[inline] + fn clone_from(&mut self, source: &Self) { + self.inner.clone_from(&source.inner) + } +} + +#[stable(feature = "box_from_path", since = "1.17.0")] +impl From<&Path> for Box<Path> { + /// Creates a boxed [`Path`] from a reference. + /// + /// This will allocate and clone `path` to it. + fn from(path: &Path) -> Box<Path> { + let boxed: Box<OsStr> = path.inner.into(); + let rw = Box::into_raw(boxed) as *mut Path; + unsafe { Box::from_raw(rw) } + } +} + +#[stable(feature = "box_from_cow", since = "1.45.0")] +impl From<Cow<'_, Path>> for Box<Path> { + /// Creates a boxed [`Path`] from a clone-on-write pointer. + /// + /// Converting from a `Cow::Owned` does not clone or allocate. + #[inline] + fn from(cow: Cow<'_, Path>) -> Box<Path> { + match cow { + Cow::Borrowed(path) => Box::from(path), + Cow::Owned(path) => Box::from(path), + } + } +} + +#[stable(feature = "path_buf_from_box", since = "1.18.0")] +impl From<Box<Path>> for PathBuf { + /// Converts a <code>[Box]<[Path]></code> into a [`PathBuf`]. + /// + /// This conversion does not allocate or copy memory. + #[inline] + fn from(boxed: Box<Path>) -> PathBuf { + boxed.into_path_buf() + } +} + +#[stable(feature = "box_from_path_buf", since = "1.20.0")] +impl From<PathBuf> for Box<Path> { + /// Converts a [`PathBuf`] into a <code>[Box]<[Path]></code>. + /// + /// This conversion currently should not allocate memory, + /// but this behavior is not guaranteed on all platforms or in all future versions. + #[inline] + fn from(p: PathBuf) -> Box<Path> { + p.into_boxed_path() + } +} + +#[stable(feature = "more_box_slice_clone", since = "1.29.0")] +impl Clone for Box<Path> { + #[inline] + fn clone(&self) -> Self { + self.to_path_buf().into_boxed_path() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: ?Sized + AsRef<OsStr>> From<&T> for PathBuf { + /// Converts a borrowed [`OsStr`] to a [`PathBuf`]. + /// + /// Allocates a [`PathBuf`] and copies the data into it. + #[inline] + fn from(s: &T) -> PathBuf { + PathBuf::from(s.as_ref().to_os_string()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl From<OsString> for PathBuf { + /// Converts an [`OsString`] into a [`PathBuf`] + /// + /// This conversion does not allocate or copy memory. + #[inline] + fn from(s: OsString) -> PathBuf { + PathBuf { inner: s } + } +} + +#[stable(feature = "from_path_buf_for_os_string", since = "1.14.0")] +impl From<PathBuf> for OsString { + /// Converts a [`PathBuf`] into an [`OsString`] + /// + /// This conversion does not allocate or copy memory. + #[inline] + fn from(path_buf: PathBuf) -> OsString { + path_buf.inner + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl From<String> for PathBuf { + /// Converts a [`String`] into a [`PathBuf`] + /// + /// This conversion does not allocate or copy memory. + #[inline] + fn from(s: String) -> PathBuf { + PathBuf::from(OsString::from(s)) + } +} + +#[stable(feature = "path_from_str", since = "1.32.0")] +impl FromStr for PathBuf { + type Err = core::convert::Infallible; + + #[inline] + fn from_str(s: &str) -> Result<Self, Self::Err> { + Ok(PathBuf::from(s)) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<P: AsRef<Path>> iter::FromIterator<P> for PathBuf { + fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> PathBuf { + let mut buf = PathBuf::new(); + buf.extend(iter); + buf + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<P: AsRef<Path>> iter::Extend<P> for PathBuf { + fn extend<I: IntoIterator<Item = P>>(&mut self, iter: I) { + iter.into_iter().for_each(move |p| self.push(p.as_ref())); + } + + #[inline] + fn extend_one(&mut self, p: P) { + self.push(p.as_ref()); + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Debug for PathBuf { + fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::Debug::fmt(&**self, formatter) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl ops::Deref for PathBuf { + type Target = Path; + #[inline] + fn deref(&self) -> &Path { + Path::new(&self.inner) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Borrow<Path> for PathBuf { + #[inline] + fn borrow(&self) -> &Path { + self.deref() + } +} + +#[stable(feature = "default_for_pathbuf", since = "1.17.0")] +impl Default for PathBuf { + #[inline] + fn default() -> Self { + PathBuf::new() + } +} + +#[stable(feature = "cow_from_path", since = "1.6.0")] +impl<'a> From<&'a Path> for Cow<'a, Path> { + /// Creates a clone-on-write pointer from a reference to + /// [`Path`]. + /// + /// This conversion does not clone or allocate. + #[inline] + fn from(s: &'a Path) -> Cow<'a, Path> { + Cow::Borrowed(s) + } +} + +#[stable(feature = "cow_from_path", since = "1.6.0")] +impl<'a> From<PathBuf> for Cow<'a, Path> { + /// Creates a clone-on-write pointer from an owned + /// instance of [`PathBuf`]. + /// + /// This conversion does not clone or allocate. + #[inline] + fn from(s: PathBuf) -> Cow<'a, Path> { + Cow::Owned(s) + } +} + +#[stable(feature = "cow_from_pathbuf_ref", since = "1.28.0")] +impl<'a> From<&'a PathBuf> for Cow<'a, Path> { + /// Creates a clone-on-write pointer from a reference to + /// [`PathBuf`]. + /// + /// This conversion does not clone or allocate. + #[inline] + fn from(p: &'a PathBuf) -> Cow<'a, Path> { + Cow::Borrowed(p.as_path()) + } +} + +#[stable(feature = "pathbuf_from_cow_path", since = "1.28.0")] +impl<'a> From<Cow<'a, Path>> for PathBuf { + /// Converts a clone-on-write pointer to an owned path. + /// + /// Converting from a `Cow::Owned` does not clone or allocate. + #[inline] + fn from(p: Cow<'a, Path>) -> Self { + p.into_owned() + } +} + +#[stable(feature = "shared_from_slice2", since = "1.24.0")] +impl From<PathBuf> for Arc<Path> { + /// Converts a [`PathBuf`] into an <code>[Arc]<[Path]></code> by moving the [`PathBuf`] data + /// into a new [`Arc`] buffer. + #[inline] + fn from(s: PathBuf) -> Arc<Path> { + let arc: Arc<OsStr> = Arc::from(s.into_os_string()); + unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) } + } +} + +#[stable(feature = "shared_from_slice2", since = "1.24.0")] +impl From<&Path> for Arc<Path> { + /// Converts a [`Path`] into an [`Arc`] by copying the [`Path`] data into a new [`Arc`] buffer. + #[inline] + fn from(s: &Path) -> Arc<Path> { + let arc: Arc<OsStr> = Arc::from(s.as_os_str()); + unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Path) } + } +} + +#[stable(feature = "shared_from_slice2", since = "1.24.0")] +impl From<PathBuf> for Rc<Path> { + /// Converts a [`PathBuf`] into an <code>[Rc]<[Path]></code> by moving the [`PathBuf`] data into + /// a new [`Rc`] buffer. + #[inline] + fn from(s: PathBuf) -> Rc<Path> { + let rc: Rc<OsStr> = Rc::from(s.into_os_string()); + unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) } + } +} + +#[stable(feature = "shared_from_slice2", since = "1.24.0")] +impl From<&Path> for Rc<Path> { + /// Converts a [`Path`] into an [`Rc`] by copying the [`Path`] data into a new [`Rc`] buffer. + #[inline] + fn from(s: &Path) -> Rc<Path> { + let rc: Rc<OsStr> = Rc::from(s.as_os_str()); + unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Path) } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl ToOwned for Path { + type Owned = PathBuf; + #[inline] + fn to_owned(&self) -> PathBuf { + self.to_path_buf() + } + #[inline] + fn clone_into(&self, target: &mut PathBuf) { + self.inner.clone_into(&mut target.inner); + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::PartialEq for PathBuf { + #[inline] + fn eq(&self, other: &PathBuf) -> bool { + self.components() == other.components() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Hash for PathBuf { + fn hash<H: Hasher>(&self, h: &mut H) { + self.as_path().hash(h) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Eq for PathBuf {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::PartialOrd for PathBuf { + #[inline] + fn partial_cmp(&self, other: &PathBuf) -> Option<cmp::Ordering> { + Some(compare_components(self.components(), other.components())) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Ord for PathBuf { + #[inline] + fn cmp(&self, other: &PathBuf) -> cmp::Ordering { + compare_components(self.components(), other.components()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<OsStr> for PathBuf { + #[inline] + fn as_ref(&self) -> &OsStr { + &self.inner[..] + } +} + +/// A slice of a path (akin to [`str`]). +/// +/// This type supports a number of operations for inspecting a path, including +/// breaking the path into its components (separated by `/` on Unix and by either +/// `/` or `\` on Windows), extracting the file name, determining whether the path +/// is absolute, and so on. +/// +/// This is an *unsized* type, meaning that it must always be used behind a +/// pointer like `&` or [`Box`]. For an owned version of this type, +/// see [`PathBuf`]. +/// +/// More details about the overall approach can be found in +/// the [module documentation](self). +/// +/// # Examples +/// +/// ``` +/// use std::path::Path; +/// use std::ffi::OsStr; +/// +/// // Note: this example does work on Windows +/// let path = Path::new("./foo/bar.txt"); +/// +/// let parent = path.parent(); +/// assert_eq!(parent, Some(Path::new("./foo"))); +/// +/// let file_stem = path.file_stem(); +/// assert_eq!(file_stem, Some(OsStr::new("bar"))); +/// +/// let extension = path.extension(); +/// assert_eq!(extension, Some(OsStr::new("txt"))); +/// ``` +#[cfg_attr(not(test), rustc_diagnostic_item = "Path")] +#[stable(feature = "rust1", since = "1.0.0")] +// FIXME: +// `Path::new` current implementation relies +// on `Path` being layout-compatible with `OsStr`. +// When attribute privacy is implemented, `Path` should be annotated as `#[repr(transparent)]`. +// Anyway, `Path` representation and layout are considered implementation detail, are +// not documented and must not be relied upon. +pub struct Path { + inner: OsStr, +} + +/// An error returned from [`Path::strip_prefix`] if the prefix was not found. +/// +/// This `struct` is created by the [`strip_prefix`] method on [`Path`]. +/// See its documentation for more. +/// +/// [`strip_prefix`]: Path::strip_prefix +#[derive(Debug, Clone, PartialEq, Eq)] +#[stable(since = "1.7.0", feature = "strip_prefix")] +pub struct StripPrefixError(()); + +impl Path { + // The following (private!) function allows construction of a path from a u8 + // slice, which is only safe when it is known to follow the OsStr encoding. + unsafe fn from_u8_slice(s: &[u8]) -> &Path { + unsafe { Path::new(u8_slice_as_os_str(s)) } + } + // The following (private!) function reveals the byte encoding used for OsStr. + fn as_u8_slice(&self) -> &[u8] { + self.inner.bytes() + } + + /// Directly wraps a string slice as a `Path` slice. + /// + /// This is a cost-free conversion. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// Path::new("foo.txt"); + /// ``` + /// + /// You can create `Path`s from `String`s, or even other `Path`s: + /// + /// ``` + /// use std::path::Path; + /// + /// let string = String::from("foo.txt"); + /// let from_string = Path::new(&string); + /// let from_path = Path::new(&from_string); + /// assert_eq!(from_string, from_path); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &Path { + unsafe { &*(s.as_ref() as *const OsStr as *const Path) } + } + + /// Yields the underlying [`OsStr`] slice. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let os_str = Path::new("foo.txt").as_os_str(); + /// assert_eq!(os_str, std::ffi::OsStr::new("foo.txt")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn as_os_str(&self) -> &OsStr { + &self.inner + } + + /// Yields a [`&str`] slice if the `Path` is valid unicode. + /// + /// This conversion may entail doing a check for UTF-8 validity. + /// Note that validation is performed because non-UTF-8 strings are + /// perfectly valid for some OS. + /// + /// [`&str`]: str + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("foo.txt"); + /// assert_eq!(path.to_str(), Some("foo.txt")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub fn to_str(&self) -> Option<&str> { + self.inner.to_str() + } + + /// Converts a `Path` to a [`Cow<str>`]. + /// + /// Any non-Unicode sequences are replaced with + /// [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD]. + /// + /// [U+FFFD]: super::char::REPLACEMENT_CHARACTER + /// + /// # Examples + /// + /// Calling `to_string_lossy` on a `Path` with valid unicode: + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("foo.txt"); + /// assert_eq!(path.to_string_lossy(), "foo.txt"); + /// ``` + /// + /// Had `path` contained invalid unicode, the `to_string_lossy` call might + /// have returned `"fo�.txt"`. + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub fn to_string_lossy(&self) -> Cow<'_, str> { + self.inner.to_string_lossy() + } + + /// Converts a `Path` to an owned [`PathBuf`]. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path_buf = Path::new("foo.txt").to_path_buf(); + /// assert_eq!(path_buf, std::path::PathBuf::from("foo.txt")); + /// ``` + #[rustc_conversion_suggestion] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn to_path_buf(&self) -> PathBuf { + PathBuf::from(self.inner.to_os_string()) + } + + /// Returns `true` if the `Path` is absolute, i.e., if it is independent of + /// the current directory. + /// + /// * On Unix, a path is absolute if it starts with the root, so + /// `is_absolute` and [`has_root`] are equivalent. + /// + /// * On Windows, a path is absolute if it has a prefix and starts with the + /// root: `c:\windows` is absolute, while `c:temp` and `\temp` are not. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// assert!(!Path::new("foo.txt").is_absolute()); + /// ``` + /// + /// [`has_root`]: Path::has_root + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[allow(deprecated)] + pub fn is_absolute(&self) -> bool { + if cfg!(target_os = "redox") { + // FIXME: Allow Redox prefixes + self.has_root() || has_redox_scheme(self.as_u8_slice()) + } else { + self.has_root() && (cfg!(any(unix, target_os = "wasi")) || self.prefix().is_some()) + } + } + + /// Returns `true` if the `Path` is relative, i.e., not absolute. + /// + /// See [`is_absolute`]'s documentation for more details. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// assert!(Path::new("foo.txt").is_relative()); + /// ``` + /// + /// [`is_absolute`]: Path::is_absolute + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn is_relative(&self) -> bool { + !self.is_absolute() + } + + fn prefix(&self) -> Option<Prefix<'_>> { + self.components().prefix + } + + /// Returns `true` if the `Path` has a root. + /// + /// * On Unix, a path has a root if it begins with `/`. + /// + /// * On Windows, a path has a root if it: + /// * has no prefix and begins with a separator, e.g., `\windows` + /// * has a prefix followed by a separator, e.g., `c:\windows` but not `c:windows` + /// * has any non-disk prefix, e.g., `\\server\share` + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// assert!(Path::new("/etc/passwd").has_root()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + #[inline] + pub fn has_root(&self) -> bool { + self.components().has_root() + } + + /// Returns the `Path` without its final component, if there is one. + /// + /// Returns [`None`] if the path terminates in a root or prefix. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("/foo/bar"); + /// let parent = path.parent().unwrap(); + /// assert_eq!(parent, Path::new("/foo")); + /// + /// let grand_parent = parent.parent().unwrap(); + /// assert_eq!(grand_parent, Path::new("/")); + /// assert_eq!(grand_parent.parent(), None); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn parent(&self) -> Option<&Path> { + let mut comps = self.components(); + let comp = comps.next_back(); + comp.and_then(|p| match p { + Component::Normal(_) | Component::CurDir | Component::ParentDir => { + Some(comps.as_path()) + } + _ => None, + }) + } + + /// Produces an iterator over `Path` and its ancestors. + /// + /// The iterator will yield the `Path` that is returned if the [`parent`] method is used zero + /// or more times. That means, the iterator will yield `&self`, `&self.parent().unwrap()`, + /// `&self.parent().unwrap().parent().unwrap()` and so on. If the [`parent`] method returns + /// [`None`], the iterator will do likewise. The iterator will always yield at least one value, + /// namely `&self`. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let mut ancestors = Path::new("/foo/bar").ancestors(); + /// assert_eq!(ancestors.next(), Some(Path::new("/foo/bar"))); + /// assert_eq!(ancestors.next(), Some(Path::new("/foo"))); + /// assert_eq!(ancestors.next(), Some(Path::new("/"))); + /// assert_eq!(ancestors.next(), None); + /// + /// let mut ancestors = Path::new("../foo/bar").ancestors(); + /// assert_eq!(ancestors.next(), Some(Path::new("../foo/bar"))); + /// assert_eq!(ancestors.next(), Some(Path::new("../foo"))); + /// assert_eq!(ancestors.next(), Some(Path::new(".."))); + /// assert_eq!(ancestors.next(), Some(Path::new(""))); + /// assert_eq!(ancestors.next(), None); + /// ``` + /// + /// [`parent`]: Path::parent + #[stable(feature = "path_ancestors", since = "1.28.0")] + #[inline] + pub fn ancestors(&self) -> Ancestors<'_> { + Ancestors { next: Some(&self) } + } + + /// Returns the final component of the `Path`, if there is one. + /// + /// If the path is a normal file, this is the file name. If it's the path of a directory, this + /// is the directory name. + /// + /// Returns [`None`] if the path terminates in `..`. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// use std::ffi::OsStr; + /// + /// assert_eq!(Some(OsStr::new("bin")), Path::new("/usr/bin/").file_name()); + /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("tmp/foo.txt").file_name()); + /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name()); + /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name()); + /// assert_eq!(None, Path::new("foo.txt/..").file_name()); + /// assert_eq!(None, Path::new("/").file_name()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn file_name(&self) -> Option<&OsStr> { + self.components().next_back().and_then(|p| match p { + Component::Normal(p) => Some(p), + _ => None, + }) + } + + /// Returns a path that, when joined onto `base`, yields `self`. + /// + /// # Errors + /// + /// If `base` is not a prefix of `self` (i.e., [`starts_with`] + /// returns `false`), returns [`Err`]. + /// + /// [`starts_with`]: Path::starts_with + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// let path = Path::new("/test/haha/foo.txt"); + /// + /// assert_eq!(path.strip_prefix("/"), Ok(Path::new("test/haha/foo.txt"))); + /// assert_eq!(path.strip_prefix("/test"), Ok(Path::new("haha/foo.txt"))); + /// assert_eq!(path.strip_prefix("/test/"), Ok(Path::new("haha/foo.txt"))); + /// assert_eq!(path.strip_prefix("/test/haha/foo.txt"), Ok(Path::new(""))); + /// assert_eq!(path.strip_prefix("/test/haha/foo.txt/"), Ok(Path::new(""))); + /// + /// assert!(path.strip_prefix("test").is_err()); + /// assert!(path.strip_prefix("/haha").is_err()); + /// + /// let prefix = PathBuf::from("/test/"); + /// assert_eq!(path.strip_prefix(prefix), Ok(Path::new("haha/foo.txt"))); + /// ``` + #[stable(since = "1.7.0", feature = "path_strip_prefix")] + pub fn strip_prefix<P>(&self, base: P) -> Result<&Path, StripPrefixError> + where + P: AsRef<Path>, + { + self._strip_prefix(base.as_ref()) + } + + fn _strip_prefix(&self, base: &Path) -> Result<&Path, StripPrefixError> { + iter_after(self.components(), base.components()) + .map(|c| c.as_path()) + .ok_or(StripPrefixError(())) + } + + /// Determines whether `base` is a prefix of `self`. + /// + /// Only considers whole path components to match. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("/etc/passwd"); + /// + /// assert!(path.starts_with("/etc")); + /// assert!(path.starts_with("/etc/")); + /// assert!(path.starts_with("/etc/passwd")); + /// assert!(path.starts_with("/etc/passwd/")); // extra slash is okay + /// assert!(path.starts_with("/etc/passwd///")); // multiple extra slashes are okay + /// + /// assert!(!path.starts_with("/e")); + /// assert!(!path.starts_with("/etc/passwd.txt")); + /// + /// assert!(!Path::new("/etc/foo.rs").starts_with("/etc/foo")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn starts_with<P: AsRef<Path>>(&self, base: P) -> bool { + self._starts_with(base.as_ref()) + } + + fn _starts_with(&self, base: &Path) -> bool { + iter_after(self.components(), base.components()).is_some() + } + + /// Determines whether `child` is a suffix of `self`. + /// + /// Only considers whole path components to match. + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("/etc/resolv.conf"); + /// + /// assert!(path.ends_with("resolv.conf")); + /// assert!(path.ends_with("etc/resolv.conf")); + /// assert!(path.ends_with("/etc/resolv.conf")); + /// + /// assert!(!path.ends_with("/resolv.conf")); + /// assert!(!path.ends_with("conf")); // use .extension() instead + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn ends_with<P: AsRef<Path>>(&self, child: P) -> bool { + self._ends_with(child.as_ref()) + } + + fn _ends_with(&self, child: &Path) -> bool { + iter_after(self.components().rev(), child.components().rev()).is_some() + } + + /// Extracts the stem (non-extension) portion of [`self.file_name`]. + /// + /// [`self.file_name`]: Path::file_name + /// + /// The stem is: + /// + /// * [`None`], if there is no file name; + /// * The entire file name if there is no embedded `.`; + /// * The entire file name if the file name begins with `.` and has no other `.`s within; + /// * Otherwise, the portion of the file name before the final `.` + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// assert_eq!("foo", Path::new("foo.rs").file_stem().unwrap()); + /// assert_eq!("foo.tar", Path::new("foo.tar.gz").file_stem().unwrap()); + /// ``` + /// + /// # See Also + /// This method is similar to [`Path::file_prefix`], which extracts the portion of the file name + /// before the *first* `.` + /// + /// [`Path::file_prefix`]: Path::file_prefix + /// + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn file_stem(&self) -> Option<&OsStr> { + self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.or(after)) + } + + /// Extracts the prefix of [`self.file_name`]. + /// + /// The prefix is: + /// + /// * [`None`], if there is no file name; + /// * The entire file name if there is no embedded `.`; + /// * The portion of the file name before the first non-beginning `.`; + /// * The entire file name if the file name begins with `.` and has no other `.`s within; + /// * The portion of the file name before the second `.` if the file name begins with `.` + /// + /// [`self.file_name`]: Path::file_name + /// + /// # Examples + /// + /// ``` + /// # #![feature(path_file_prefix)] + /// use std::path::Path; + /// + /// assert_eq!("foo", Path::new("foo.rs").file_prefix().unwrap()); + /// assert_eq!("foo", Path::new("foo.tar.gz").file_prefix().unwrap()); + /// ``` + /// + /// # See Also + /// This method is similar to [`Path::file_stem`], which extracts the portion of the file name + /// before the *last* `.` + /// + /// [`Path::file_stem`]: Path::file_stem + /// + #[unstable(feature = "path_file_prefix", issue = "86319")] + #[must_use] + pub fn file_prefix(&self) -> Option<&OsStr> { + self.file_name().map(split_file_at_dot).and_then(|(before, _after)| Some(before)) + } + + /// Extracts the extension of [`self.file_name`], if possible. + /// + /// The extension is: + /// + /// * [`None`], if there is no file name; + /// * [`None`], if there is no embedded `.`; + /// * [`None`], if the file name begins with `.` and has no other `.`s within; + /// * Otherwise, the portion of the file name after the final `.` + /// + /// [`self.file_name`]: Path::file_name + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// assert_eq!("rs", Path::new("foo.rs").extension().unwrap()); + /// assert_eq!("gz", Path::new("foo.tar.gz").extension().unwrap()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn extension(&self) -> Option<&OsStr> { + self.file_name().map(rsplit_file_at_dot).and_then(|(before, after)| before.and(after)) + } + + /// Creates an owned [`PathBuf`] with `path` adjoined to `self`. + /// + /// See [`PathBuf::push`] for more details on what it means to adjoin a path. + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// assert_eq!(Path::new("/etc").join("passwd"), PathBuf::from("/etc/passwd")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn join<P: AsRef<Path>>(&self, path: P) -> PathBuf { + self._join(path.as_ref()) + } + + fn _join(&self, path: &Path) -> PathBuf { + let mut buf = self.to_path_buf(); + buf.push(path); + buf + } + + /// Creates an owned [`PathBuf`] like `self` but with the given file name. + /// + /// See [`PathBuf::set_file_name`] for more details. + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// let path = Path::new("/tmp/foo.txt"); + /// assert_eq!(path.with_file_name("bar.txt"), PathBuf::from("/tmp/bar.txt")); + /// + /// let path = Path::new("/tmp"); + /// assert_eq!(path.with_file_name("var"), PathBuf::from("/var")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn with_file_name<S: AsRef<OsStr>>(&self, file_name: S) -> PathBuf { + self._with_file_name(file_name.as_ref()) + } + + fn _with_file_name(&self, file_name: &OsStr) -> PathBuf { + let mut buf = self.to_path_buf(); + buf.set_file_name(file_name); + buf + } + + /// Creates an owned [`PathBuf`] like `self` but with the given extension. + /// + /// See [`PathBuf::set_extension`] for more details. + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, PathBuf}; + /// + /// let path = Path::new("foo.rs"); + /// assert_eq!(path.with_extension("txt"), PathBuf::from("foo.txt")); + /// + /// let path = Path::new("foo.tar.gz"); + /// assert_eq!(path.with_extension(""), PathBuf::from("foo.tar")); + /// assert_eq!(path.with_extension("xz"), PathBuf::from("foo.tar.xz")); + /// assert_eq!(path.with_extension("").with_extension("txt"), PathBuf::from("foo.txt")); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn with_extension<S: AsRef<OsStr>>(&self, extension: S) -> PathBuf { + self._with_extension(extension.as_ref()) + } + + fn _with_extension(&self, extension: &OsStr) -> PathBuf { + let mut buf = self.to_path_buf(); + buf.set_extension(extension); + buf + } + + /// Produces an iterator over the [`Component`]s of the path. + /// + /// When parsing the path, there is a small amount of normalization: + /// + /// * Repeated separators are ignored, so `a/b` and `a//b` both have + /// `a` and `b` as components. + /// + /// * Occurrences of `.` are normalized away, except if they are at the + /// beginning of the path. For example, `a/./b`, `a/b/`, `a/b/.` and + /// `a/b` all have `a` and `b` as components, but `./a/b` starts with + /// an additional [`CurDir`] component. + /// + /// * A trailing slash is normalized away, `/a/b` and `/a/b/` are equivalent. + /// + /// Note that no other normalization takes place; in particular, `a/c` + /// and `a/b/../c` are distinct, to account for the possibility that `b` + /// is a symbolic link (so its parent isn't `a`). + /// + /// # Examples + /// + /// ``` + /// use std::path::{Path, Component}; + /// use std::ffi::OsStr; + /// + /// let mut components = Path::new("/tmp/foo.txt").components(); + /// + /// assert_eq!(components.next(), Some(Component::RootDir)); + /// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("tmp")))); + /// assert_eq!(components.next(), Some(Component::Normal(OsStr::new("foo.txt")))); + /// assert_eq!(components.next(), None) + /// ``` + /// + /// [`CurDir`]: Component::CurDir + #[stable(feature = "rust1", since = "1.0.0")] + pub fn components(&self) -> Components<'_> { + let prefix = parse_prefix(self.as_os_str()); + Components { + path: self.as_u8_slice(), + prefix, + has_physical_root: has_physical_root(self.as_u8_slice(), prefix) + || has_redox_scheme(self.as_u8_slice()), + front: State::Prefix, + back: State::Body, + } + } + + /// Produces an iterator over the path's components viewed as [`OsStr`] + /// slices. + /// + /// For more information about the particulars of how the path is separated + /// into components, see [`components`]. + /// + /// [`components`]: Path::components + /// + /// # Examples + /// + /// ``` + /// use std::path::{self, Path}; + /// use std::ffi::OsStr; + /// + /// let mut it = Path::new("/tmp/foo.txt").iter(); + /// assert_eq!(it.next(), Some(OsStr::new(&path::MAIN_SEPARATOR.to_string()))); + /// assert_eq!(it.next(), Some(OsStr::new("tmp"))); + /// assert_eq!(it.next(), Some(OsStr::new("foo.txt"))); + /// assert_eq!(it.next(), None) + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn iter(&self) -> Iter<'_> { + Iter { inner: self.components() } + } + + /// Returns an object that implements [`Display`] for safely printing paths + /// that may contain non-Unicode data. This may perform lossy conversion, + /// depending on the platform. If you would like an implementation which + /// escapes the path please use [`Debug`] instead. + /// + /// [`Display`]: fmt::Display + /// + /// # Examples + /// + /// ``` + /// use std::path::Path; + /// + /// let path = Path::new("/tmp/foo.rs"); + /// + /// println!("{}", path.display()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use = "this does not display the path, \ + it returns an object that can be displayed"] + #[inline] + pub fn display(&self) -> Display<'_> { + Display { path: self } + } + + /// Queries the file system to get information about a file, directory, etc. + /// + /// This function will traverse symbolic links to query information about the + /// destination file. + /// + /// This is an alias to [`fs::metadata`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// + /// let path = Path::new("/Minas/tirith"); + /// let metadata = path.metadata().expect("metadata call failed"); + /// println!("{:?}", metadata.file_type()); + /// ``` + #[stable(feature = "path_ext", since = "1.5.0")] + #[inline] + pub fn metadata(&self) -> io::Result<fs::Metadata> { + fs::metadata(self) + } + + /// Queries the metadata about a file without following symlinks. + /// + /// This is an alias to [`fs::symlink_metadata`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// + /// let path = Path::new("/Minas/tirith"); + /// let metadata = path.symlink_metadata().expect("symlink_metadata call failed"); + /// println!("{:?}", metadata.file_type()); + /// ``` + #[stable(feature = "path_ext", since = "1.5.0")] + #[inline] + pub fn symlink_metadata(&self) -> io::Result<fs::Metadata> { + fs::symlink_metadata(self) + } + + /// Returns the canonical, absolute form of the path with all intermediate + /// components normalized and symbolic links resolved. + /// + /// This is an alias to [`fs::canonicalize`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::{Path, PathBuf}; + /// + /// let path = Path::new("/foo/test/../test/bar.rs"); + /// assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs")); + /// ``` + #[stable(feature = "path_ext", since = "1.5.0")] + #[inline] + pub fn canonicalize(&self) -> io::Result<PathBuf> { + fs::canonicalize(self) + } + + /// Reads a symbolic link, returning the file that the link points to. + /// + /// This is an alias to [`fs::read_link`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// + /// let path = Path::new("/laputa/sky_castle.rs"); + /// let path_link = path.read_link().expect("read_link call failed"); + /// ``` + #[stable(feature = "path_ext", since = "1.5.0")] + #[inline] + pub fn read_link(&self) -> io::Result<PathBuf> { + fs::read_link(self) + } + + /// Returns an iterator over the entries within a directory. + /// + /// The iterator will yield instances of <code>[io::Result]<[fs::DirEntry]></code>. New + /// errors may be encountered after an iterator is initially constructed. + /// + /// This is an alias to [`fs::read_dir`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// + /// let path = Path::new("/laputa"); + /// for entry in path.read_dir().expect("read_dir call failed") { + /// if let Ok(entry) = entry { + /// println!("{:?}", entry.path()); + /// } + /// } + /// ``` + #[stable(feature = "path_ext", since = "1.5.0")] + #[inline] + pub fn read_dir(&self) -> io::Result<fs::ReadDir> { + fs::read_dir(self) + } + + /// Returns `true` if the path points at an existing entity. + /// + /// Warning: this method may be error-prone, consider using [`try_exists()`] instead! + /// It also has a risk of introducing time-of-check to time-of-use (TOCTOU) bugs. + /// + /// This function will traverse symbolic links to query information about the + /// destination file. + /// + /// If you cannot access the metadata of the file, e.g. because of a + /// permission error or broken symbolic links, this will return `false`. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// assert!(!Path::new("does_not_exist.txt").exists()); + /// ``` + /// + /// # See Also + /// + /// This is a convenience function that coerces errors to false. If you want to + /// check errors, call [`Path::try_exists`]. + /// + /// [`try_exists()`]: Self::try_exists + #[stable(feature = "path_ext", since = "1.5.0")] + #[must_use] + #[inline] + pub fn exists(&self) -> bool { + fs::metadata(self).is_ok() + } + + /// Returns `Ok(true)` if the path points at an existing entity. + /// + /// This function will traverse symbolic links to query information about the + /// destination file. In case of broken symbolic links this will return `Ok(false)`. + /// + /// As opposed to the [`exists()`] method, this one doesn't silently ignore errors + /// unrelated to the path not existing. (E.g. it will return `Err(_)` in case of permission + /// denied on some of the parent directories.) + /// + /// Note that while this avoids some pitfalls of the `exists()` method, it still can not + /// prevent time-of-check to time-of-use (TOCTOU) bugs. You should only use it in scenarios + /// where those bugs are not an issue. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// assert!(!Path::new("does_not_exist.txt").try_exists().expect("Can't check existence of file does_not_exist.txt")); + /// assert!(Path::new("/root/secret_file.txt").try_exists().is_err()); + /// ``` + /// + /// [`exists()`]: Self::exists + #[stable(feature = "path_try_exists", since = "1.63.0")] + #[inline] + pub fn try_exists(&self) -> io::Result<bool> { + fs::try_exists(self) + } + + /// Returns `true` if the path exists on disk and is pointing at a regular file. + /// + /// This function will traverse symbolic links to query information about the + /// destination file. + /// + /// If you cannot access the metadata of the file, e.g. because of a + /// permission error or broken symbolic links, this will return `false`. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// assert_eq!(Path::new("./is_a_directory/").is_file(), false); + /// assert_eq!(Path::new("a_file.txt").is_file(), true); + /// ``` + /// + /// # See Also + /// + /// This is a convenience function that coerces errors to false. If you want to + /// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call + /// [`fs::Metadata::is_file`] if it was [`Ok`]. + /// + /// When the goal is simply to read from (or write to) the source, the most + /// reliable way to test the source can be read (or written to) is to open + /// it. Only using `is_file` can break workflows like `diff <( prog_a )` on + /// a Unix-like system for example. See [`fs::File::open`] or + /// [`fs::OpenOptions::open`] for more information. + #[stable(feature = "path_ext", since = "1.5.0")] + #[must_use] + pub fn is_file(&self) -> bool { + fs::metadata(self).map(|m| m.is_file()).unwrap_or(false) + } + + /// Returns `true` if the path exists on disk and is pointing at a directory. + /// + /// This function will traverse symbolic links to query information about the + /// destination file. + /// + /// If you cannot access the metadata of the file, e.g. because of a + /// permission error or broken symbolic links, this will return `false`. + /// + /// # Examples + /// + /// ```no_run + /// use std::path::Path; + /// assert_eq!(Path::new("./is_a_directory/").is_dir(), true); + /// assert_eq!(Path::new("a_file.txt").is_dir(), false); + /// ``` + /// + /// # See Also + /// + /// This is a convenience function that coerces errors to false. If you want to + /// check errors, call [`fs::metadata`] and handle its [`Result`]. Then call + /// [`fs::Metadata::is_dir`] if it was [`Ok`]. + #[stable(feature = "path_ext", since = "1.5.0")] + #[must_use] + pub fn is_dir(&self) -> bool { + fs::metadata(self).map(|m| m.is_dir()).unwrap_or(false) + } + + /// Returns `true` if the path exists on disk and is pointing at a symbolic link. + /// + /// This function will not traverse symbolic links. + /// In case of a broken symbolic link this will also return true. + /// + /// If you cannot access the directory containing the file, e.g., because of a + /// permission error, this will return false. + /// + /// # Examples + /// + #[cfg_attr(unix, doc = "```no_run")] + #[cfg_attr(not(unix), doc = "```ignore")] + /// use std::path::Path; + /// use std::os::unix::fs::symlink; + /// + /// let link_path = Path::new("link"); + /// symlink("/origin_does_not_exist/", link_path).unwrap(); + /// assert_eq!(link_path.is_symlink(), true); + /// assert_eq!(link_path.exists(), false); + /// ``` + /// + /// # See Also + /// + /// This is a convenience function that coerces errors to false. If you want to + /// check errors, call [`fs::symlink_metadata`] and handle its [`Result`]. Then call + /// [`fs::Metadata::is_symlink`] if it was [`Ok`]. + #[must_use] + #[stable(feature = "is_symlink", since = "1.58.0")] + pub fn is_symlink(&self) -> bool { + fs::symlink_metadata(self).map(|m| m.is_symlink()).unwrap_or(false) + } + + /// Converts a [`Box<Path>`](Box) into a [`PathBuf`] without copying or + /// allocating. + #[stable(feature = "into_boxed_path", since = "1.20.0")] + #[must_use = "`self` will be dropped if the result is not used"] + pub fn into_path_buf(self: Box<Path>) -> PathBuf { + let rw = Box::into_raw(self) as *mut OsStr; + let inner = unsafe { Box::from_raw(rw) }; + PathBuf { inner: OsString::from(inner) } + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<OsStr> for Path { + #[inline] + fn as_ref(&self) -> &OsStr { + &self.inner + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Debug for Path { + fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::Debug::fmt(&self.inner, formatter) + } +} + +/// Helper struct for safely printing paths with [`format!`] and `{}`. +/// +/// A [`Path`] might contain non-Unicode data. This `struct` implements the +/// [`Display`] trait in a way that mitigates that. It is created by the +/// [`display`](Path::display) method on [`Path`]. This may perform lossy +/// conversion, depending on the platform. If you would like an implementation +/// which escapes the path please use [`Debug`] instead. +/// +/// # Examples +/// +/// ``` +/// use std::path::Path; +/// +/// let path = Path::new("/tmp/foo.rs"); +/// +/// println!("{}", path.display()); +/// ``` +/// +/// [`Display`]: fmt::Display +/// [`format!`]: crate::format +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Display<'a> { + path: &'a Path, +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Debug for Display<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::Debug::fmt(&self.path, f) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Display for Display<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.path.inner.display(f) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::PartialEq for Path { + #[inline] + fn eq(&self, other: &Path) -> bool { + self.components() == other.components() + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Hash for Path { + fn hash<H: Hasher>(&self, h: &mut H) { + let bytes = self.as_u8_slice(); + let (prefix_len, verbatim) = match parse_prefix(&self.inner) { + Some(prefix) => { + prefix.hash(h); + (prefix.len(), prefix.is_verbatim()) + } + None => (0, false), + }; + let bytes = &bytes[prefix_len..]; + + let mut component_start = 0; + let mut bytes_hashed = 0; + + for i in 0..bytes.len() { + let is_sep = if verbatim { is_verbatim_sep(bytes[i]) } else { is_sep_byte(bytes[i]) }; + if is_sep { + if i > component_start { + let to_hash = &bytes[component_start..i]; + h.write(to_hash); + bytes_hashed += to_hash.len(); + } + + // skip over separator and optionally a following CurDir item + // since components() would normalize these away. + component_start = i + 1; + + let tail = &bytes[component_start..]; + + if !verbatim { + component_start += match tail { + [b'.'] => 1, + [b'.', sep @ _, ..] if is_sep_byte(*sep) => 1, + _ => 0, + }; + } + } + } + + if component_start < bytes.len() { + let to_hash = &bytes[component_start..]; + h.write(to_hash); + bytes_hashed += to_hash.len(); + } + + h.write_usize(bytes_hashed); + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Eq for Path {} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::PartialOrd for Path { + #[inline] + fn partial_cmp(&self, other: &Path) -> Option<cmp::Ordering> { + Some(compare_components(self.components(), other.components())) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl cmp::Ord for Path { + #[inline] + fn cmp(&self, other: &Path) -> cmp::Ordering { + compare_components(self.components(), other.components()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for Path { + #[inline] + fn as_ref(&self) -> &Path { + self + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for OsStr { + #[inline] + fn as_ref(&self) -> &Path { + Path::new(self) + } +} + +#[stable(feature = "cow_os_str_as_ref_path", since = "1.8.0")] +impl AsRef<Path> for Cow<'_, OsStr> { + #[inline] + fn as_ref(&self) -> &Path { + Path::new(self) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for OsString { + #[inline] + fn as_ref(&self) -> &Path { + Path::new(self) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for str { + #[inline] + fn as_ref(&self) -> &Path { + Path::new(self) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for String { + #[inline] + fn as_ref(&self) -> &Path { + Path::new(self) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl AsRef<Path> for PathBuf { + #[inline] + fn as_ref(&self) -> &Path { + self + } +} + +#[stable(feature = "path_into_iter", since = "1.6.0")] +impl<'a> IntoIterator for &'a PathBuf { + type Item = &'a OsStr; + type IntoIter = Iter<'a>; + #[inline] + fn into_iter(self) -> Iter<'a> { + self.iter() + } +} + +#[stable(feature = "path_into_iter", since = "1.6.0")] +impl<'a> IntoIterator for &'a Path { + type Item = &'a OsStr; + type IntoIter = Iter<'a>; + #[inline] + fn into_iter(self) -> Iter<'a> { + self.iter() + } +} + +macro_rules! impl_cmp { + ($lhs:ty, $rhs: ty) => { + #[stable(feature = "partialeq_path", since = "1.6.0")] + impl<'a, 'b> PartialEq<$rhs> for $lhs { + #[inline] + fn eq(&self, other: &$rhs) -> bool { + <Path as PartialEq>::eq(self, other) + } + } + + #[stable(feature = "partialeq_path", since = "1.6.0")] + impl<'a, 'b> PartialEq<$lhs> for $rhs { + #[inline] + fn eq(&self, other: &$lhs) -> bool { + <Path as PartialEq>::eq(self, other) + } + } + + #[stable(feature = "cmp_path", since = "1.8.0")] + impl<'a, 'b> PartialOrd<$rhs> for $lhs { + #[inline] + fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> { + <Path as PartialOrd>::partial_cmp(self, other) + } + } + + #[stable(feature = "cmp_path", since = "1.8.0")] + impl<'a, 'b> PartialOrd<$lhs> for $rhs { + #[inline] + fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> { + <Path as PartialOrd>::partial_cmp(self, other) + } + } + }; +} + +impl_cmp!(PathBuf, Path); +impl_cmp!(PathBuf, &'a Path); +impl_cmp!(Cow<'a, Path>, Path); +impl_cmp!(Cow<'a, Path>, &'b Path); +impl_cmp!(Cow<'a, Path>, PathBuf); + +macro_rules! impl_cmp_os_str { + ($lhs:ty, $rhs: ty) => { + #[stable(feature = "cmp_path", since = "1.8.0")] + impl<'a, 'b> PartialEq<$rhs> for $lhs { + #[inline] + fn eq(&self, other: &$rhs) -> bool { + <Path as PartialEq>::eq(self, other.as_ref()) + } + } + + #[stable(feature = "cmp_path", since = "1.8.0")] + impl<'a, 'b> PartialEq<$lhs> for $rhs { + #[inline] + fn eq(&self, other: &$lhs) -> bool { + <Path as PartialEq>::eq(self.as_ref(), other) + } + } + + #[stable(feature = "cmp_path", since = "1.8.0")] + impl<'a, 'b> PartialOrd<$rhs> for $lhs { + #[inline] + fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> { + <Path as PartialOrd>::partial_cmp(self, other.as_ref()) + } + } + + #[stable(feature = "cmp_path", since = "1.8.0")] + impl<'a, 'b> PartialOrd<$lhs> for $rhs { + #[inline] + fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> { + <Path as PartialOrd>::partial_cmp(self.as_ref(), other) + } + } + }; +} + +impl_cmp_os_str!(PathBuf, OsStr); +impl_cmp_os_str!(PathBuf, &'a OsStr); +impl_cmp_os_str!(PathBuf, Cow<'a, OsStr>); +impl_cmp_os_str!(PathBuf, OsString); +impl_cmp_os_str!(Path, OsStr); +impl_cmp_os_str!(Path, &'a OsStr); +impl_cmp_os_str!(Path, Cow<'a, OsStr>); +impl_cmp_os_str!(Path, OsString); +impl_cmp_os_str!(&'a Path, OsStr); +impl_cmp_os_str!(&'a Path, Cow<'b, OsStr>); +impl_cmp_os_str!(&'a Path, OsString); +impl_cmp_os_str!(Cow<'a, Path>, OsStr); +impl_cmp_os_str!(Cow<'a, Path>, &'b OsStr); +impl_cmp_os_str!(Cow<'a, Path>, OsString); + +#[stable(since = "1.7.0", feature = "strip_prefix")] +impl fmt::Display for StripPrefixError { + #[allow(deprecated, deprecated_in_future)] + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.description().fmt(f) + } +} + +#[stable(since = "1.7.0", feature = "strip_prefix")] +impl Error for StripPrefixError { + #[allow(deprecated)] + fn description(&self) -> &str { + "prefix not found" + } +} + +/// Makes the path absolute without accessing the filesystem. +/// +/// If the path is relative, the current directory is used as the base directory. +/// All intermediate components will be resolved according to platforms-specific +/// rules but unlike [`canonicalize`][crate::fs::canonicalize] this does not +/// resolve symlinks and may succeed even if the path does not exist. +/// +/// If the `path` is empty or getting the +/// [current directory][crate::env::current_dir] fails then an error will be +/// returned. +/// +/// # Examples +/// +/// ## Posix paths +/// +/// ``` +/// #![feature(absolute_path)] +/// # #[cfg(unix)] +/// fn main() -> std::io::Result<()> { +/// use std::path::{self, Path}; +/// +/// // Relative to absolute +/// let absolute = path::absolute("foo/./bar")?; +/// assert!(absolute.ends_with("foo/bar")); +/// +/// // Absolute to absolute +/// let absolute = path::absolute("/foo//test/.././bar.rs")?; +/// assert_eq!(absolute, Path::new("/foo/test/../bar.rs")); +/// Ok(()) +/// } +/// # #[cfg(not(unix))] +/// # fn main() {} +/// ``` +/// +/// The path is resolved using [POSIX semantics][posix-semantics] except that +/// it stops short of resolving symlinks. This means it will keep `..` +/// components and trailing slashes. +/// +/// ## Windows paths +/// +/// ``` +/// #![feature(absolute_path)] +/// # #[cfg(windows)] +/// fn main() -> std::io::Result<()> { +/// use std::path::{self, Path}; +/// +/// // Relative to absolute +/// let absolute = path::absolute("foo/./bar")?; +/// assert!(absolute.ends_with(r"foo\bar")); +/// +/// // Absolute to absolute +/// let absolute = path::absolute(r"C:\foo//test\..\./bar.rs")?; +/// +/// assert_eq!(absolute, Path::new(r"C:\foo\bar.rs")); +/// Ok(()) +/// } +/// # #[cfg(not(windows))] +/// # fn main() {} +/// ``` +/// +/// For verbatim paths this will simply return the path as given. For other +/// paths this is currently equivalent to calling [`GetFullPathNameW`][windows-path] +/// This may change in the future. +/// +/// [posix-semantics]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13 +/// [windows-path]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfullpathnamew +#[unstable(feature = "absolute_path", issue = "92750")] +pub fn absolute<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> { + let path = path.as_ref(); + if path.as_os_str().is_empty() { + Err(io::const_io_error!(io::ErrorKind::InvalidInput, "cannot make an empty path absolute",)) + } else { + sys::path::absolute(path) + } +} |