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Diffstat (limited to 'library/std/src/fs.rs')
| -rw-r--r-- | library/std/src/fs.rs | 2428 |
1 files changed, 2428 insertions, 0 deletions
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs new file mode 100644 index 000000000..c8e131b6e --- /dev/null +++ b/library/std/src/fs.rs @@ -0,0 +1,2428 @@ +//! Filesystem manipulation operations. +//! +//! This module contains basic methods to manipulate the contents of the local +//! filesystem. All methods in this module represent cross-platform filesystem +//! operations. Extra platform-specific functionality can be found in the +//! extension traits of `std::os::$platform`. + +#![stable(feature = "rust1", since = "1.0.0")] +#![deny(unsafe_op_in_unsafe_fn)] + +#[cfg(all(test, not(any(target_os = "emscripten", target_env = "sgx"))))] +mod tests; + +use crate::ffi::OsString; +use crate::fmt; +use crate::io::{self, IoSlice, IoSliceMut, Read, ReadBuf, Seek, SeekFrom, Write}; +use crate::path::{Path, PathBuf}; +use crate::sys::fs as fs_imp; +use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner}; +use crate::time::SystemTime; + +/// A reference to an open file on the filesystem. +/// +/// An instance of a `File` can be read and/or written depending on what options +/// it was opened with. Files also implement [`Seek`] to alter the logical cursor +/// that the file contains internally. +/// +/// Files are automatically closed when they go out of scope. Errors detected +/// on closing are ignored by the implementation of `Drop`. Use the method +/// [`sync_all`] if these errors must be manually handled. +/// +/// # Examples +/// +/// Creates a new file and write bytes to it (you can also use [`write()`]): +/// +/// ```no_run +/// use std::fs::File; +/// use std::io::prelude::*; +/// +/// fn main() -> std::io::Result<()> { +/// let mut file = File::create("foo.txt")?; +/// file.write_all(b"Hello, world!")?; +/// Ok(()) +/// } +/// ``` +/// +/// Read the contents of a file into a [`String`] (you can also use [`read`]): +/// +/// ```no_run +/// use std::fs::File; +/// use std::io::prelude::*; +/// +/// fn main() -> std::io::Result<()> { +/// let mut file = File::open("foo.txt")?; +/// let mut contents = String::new(); +/// file.read_to_string(&mut contents)?; +/// assert_eq!(contents, "Hello, world!"); +/// Ok(()) +/// } +/// ``` +/// +/// It can be more efficient to read the contents of a file with a buffered +/// [`Read`]er. This can be accomplished with [`BufReader<R>`]: +/// +/// ```no_run +/// use std::fs::File; +/// use std::io::BufReader; +/// use std::io::prelude::*; +/// +/// fn main() -> std::io::Result<()> { +/// let file = File::open("foo.txt")?; +/// let mut buf_reader = BufReader::new(file); +/// let mut contents = String::new(); +/// buf_reader.read_to_string(&mut contents)?; +/// assert_eq!(contents, "Hello, world!"); +/// Ok(()) +/// } +/// ``` +/// +/// Note that, although read and write methods require a `&mut File`, because +/// of the interfaces for [`Read`] and [`Write`], the holder of a `&File` can +/// still modify the file, either through methods that take `&File` or by +/// retrieving the underlying OS object and modifying the file that way. +/// Additionally, many operating systems allow concurrent modification of files +/// by different processes. Avoid assuming that holding a `&File` means that the +/// file will not change. +/// +/// # Platform-specific behavior +/// +/// On Windows, the implementation of [`Read`] and [`Write`] traits for `File` +/// perform synchronous I/O operations. Therefore the underlying file must not +/// have been opened for asynchronous I/O (e.g. by using `FILE_FLAG_OVERLAPPED`). +/// +/// [`BufReader<R>`]: io::BufReader +/// [`sync_all`]: File::sync_all +#[stable(feature = "rust1", since = "1.0.0")] +#[cfg_attr(not(test), rustc_diagnostic_item = "File")] +pub struct File { + inner: fs_imp::File, +} + +/// Metadata information about a file. +/// +/// This structure is returned from the [`metadata`] or +/// [`symlink_metadata`] function or method and represents known +/// metadata about a file such as its permissions, size, modification +/// times, etc. +#[stable(feature = "rust1", since = "1.0.0")] +#[derive(Clone)] +pub struct Metadata(fs_imp::FileAttr); + +/// Iterator over the entries in a directory. +/// +/// This iterator is returned from the [`read_dir`] function of this module and +/// will yield instances of <code>[io::Result]<[DirEntry]></code>. Through a [`DirEntry`] +/// information like the entry's path and possibly other metadata can be +/// learned. +/// +/// The order in which this iterator returns entries is platform and filesystem +/// dependent. +/// +/// # Errors +/// +/// This [`io::Result`] will be an [`Err`] if there's some sort of intermittent +/// IO error during iteration. +#[stable(feature = "rust1", since = "1.0.0")] +#[derive(Debug)] +pub struct ReadDir(fs_imp::ReadDir); + +/// Entries returned by the [`ReadDir`] iterator. +/// +/// An instance of `DirEntry` represents an entry inside of a directory on the +/// filesystem. Each entry can be inspected via methods to learn about the full +/// path or possibly other metadata through per-platform extension traits. +/// +/// # Platform-specific behavior +/// +/// On Unix, the `DirEntry` struct contains an internal reference to the open +/// directory. Holding `DirEntry` objects will consume a file handle even +/// after the `ReadDir` iterator is dropped. +/// +/// Note that this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +#[stable(feature = "rust1", since = "1.0.0")] +pub struct DirEntry(fs_imp::DirEntry); + +/// Options and flags which can be used to configure how a file is opened. +/// +/// This builder exposes the ability to configure how a [`File`] is opened and +/// what operations are permitted on the open file. The [`File::open`] and +/// [`File::create`] methods are aliases for commonly used options using this +/// builder. +/// +/// Generally speaking, when using `OpenOptions`, you'll first call +/// [`OpenOptions::new`], then chain calls to methods to set each option, then +/// call [`OpenOptions::open`], passing the path of the file you're trying to +/// open. This will give you a [`io::Result`] with a [`File`] inside that you +/// can further operate on. +/// +/// # Examples +/// +/// Opening a file to read: +/// +/// ```no_run +/// use std::fs::OpenOptions; +/// +/// let file = OpenOptions::new().read(true).open("foo.txt"); +/// ``` +/// +/// Opening a file for both reading and writing, as well as creating it if it +/// doesn't exist: +/// +/// ```no_run +/// use std::fs::OpenOptions; +/// +/// let file = OpenOptions::new() +/// .read(true) +/// .write(true) +/// .create(true) +/// .open("foo.txt"); +/// ``` +#[derive(Clone, Debug)] +#[stable(feature = "rust1", since = "1.0.0")] +pub struct OpenOptions(fs_imp::OpenOptions); + +/// Representation of the various timestamps on a file. +#[derive(Copy, Clone, Debug, Default)] +#[unstable(feature = "file_set_times", issue = "98245")] +pub struct FileTimes(fs_imp::FileTimes); + +/// Representation of the various permissions on a file. +/// +/// This module only currently provides one bit of information, +/// [`Permissions::readonly`], which is exposed on all currently supported +/// platforms. Unix-specific functionality, such as mode bits, is available +/// through the [`PermissionsExt`] trait. +/// +/// [`PermissionsExt`]: crate::os::unix::fs::PermissionsExt +#[derive(Clone, PartialEq, Eq, Debug)] +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Permissions(fs_imp::FilePermissions); + +/// A structure representing a type of file with accessors for each file type. +/// It is returned by [`Metadata::file_type`] method. +#[stable(feature = "file_type", since = "1.1.0")] +#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)] +#[cfg_attr(not(test), rustc_diagnostic_item = "FileType")] +pub struct FileType(fs_imp::FileType); + +/// A builder used to create directories in various manners. +/// +/// This builder also supports platform-specific options. +#[stable(feature = "dir_builder", since = "1.6.0")] +#[cfg_attr(not(test), rustc_diagnostic_item = "DirBuilder")] +#[derive(Debug)] +pub struct DirBuilder { + inner: fs_imp::DirBuilder, + recursive: bool, +} + +/// Read the entire contents of a file into a bytes vector. +/// +/// This is a convenience function for using [`File::open`] and [`read_to_end`] +/// with fewer imports and without an intermediate variable. +/// +/// [`read_to_end`]: Read::read_to_end +/// +/// # Errors +/// +/// This function will return an error if `path` does not already exist. +/// Other errors may also be returned according to [`OpenOptions::open`]. +/// +/// It will also return an error if it encounters while reading an error +/// of a kind other than [`io::ErrorKind::Interrupted`]. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// use std::net::SocketAddr; +/// +/// fn main() -> Result<(), Box<dyn std::error::Error + 'static>> { +/// let foo: SocketAddr = String::from_utf8_lossy(&fs::read("address.txt")?).parse()?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "fs_read_write_bytes", since = "1.26.0")] +pub fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> { + fn inner(path: &Path) -> io::Result<Vec<u8>> { + let mut file = File::open(path)?; + let mut bytes = Vec::new(); + file.read_to_end(&mut bytes)?; + Ok(bytes) + } + inner(path.as_ref()) +} + +/// Read the entire contents of a file into a string. +/// +/// This is a convenience function for using [`File::open`] and [`read_to_string`] +/// with fewer imports and without an intermediate variable. +/// +/// [`read_to_string`]: Read::read_to_string +/// +/// # Errors +/// +/// This function will return an error if `path` does not already exist. +/// Other errors may also be returned according to [`OpenOptions::open`]. +/// +/// It will also return an error if it encounters while reading an error +/// of a kind other than [`io::ErrorKind::Interrupted`], +/// or if the contents of the file are not valid UTF-8. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// use std::net::SocketAddr; +/// use std::error::Error; +/// +/// fn main() -> Result<(), Box<dyn Error>> { +/// let foo: SocketAddr = fs::read_to_string("address.txt")?.parse()?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "fs_read_write", since = "1.26.0")] +pub fn read_to_string<P: AsRef<Path>>(path: P) -> io::Result<String> { + fn inner(path: &Path) -> io::Result<String> { + let mut file = File::open(path)?; + let mut string = String::new(); + file.read_to_string(&mut string)?; + Ok(string) + } + inner(path.as_ref()) +} + +/// Write a slice as the entire contents of a file. +/// +/// This function will create a file if it does not exist, +/// and will entirely replace its contents if it does. +/// +/// Depending on the platform, this function may fail if the +/// full directory path does not exist. +/// +/// This is a convenience function for using [`File::create`] and [`write_all`] +/// with fewer imports. +/// +/// [`write_all`]: Write::write_all +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::write("foo.txt", b"Lorem ipsum")?; +/// fs::write("bar.txt", "dolor sit")?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "fs_read_write_bytes", since = "1.26.0")] +pub fn write<P: AsRef<Path>, C: AsRef<[u8]>>(path: P, contents: C) -> io::Result<()> { + fn inner(path: &Path, contents: &[u8]) -> io::Result<()> { + File::create(path)?.write_all(contents) + } + inner(path.as_ref(), contents.as_ref()) +} + +impl File { + /// Attempts to open a file in read-only mode. + /// + /// See the [`OpenOptions::open`] method for more details. + /// + /// # Errors + /// + /// This function will return an error if `path` does not already exist. + /// Other errors may also be returned according to [`OpenOptions::open`]. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::open("foo.txt")?; + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn open<P: AsRef<Path>>(path: P) -> io::Result<File> { + OpenOptions::new().read(true).open(path.as_ref()) + } + + /// Opens a file in write-only mode. + /// + /// This function will create a file if it does not exist, + /// and will truncate it if it does. + /// + /// Depending on the platform, this function may fail if the + /// full directory path does not exist. + /// + /// See the [`OpenOptions::open`] function for more details. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::create("foo.txt")?; + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn create<P: AsRef<Path>>(path: P) -> io::Result<File> { + OpenOptions::new().write(true).create(true).truncate(true).open(path.as_ref()) + } + + /// Returns a new OpenOptions object. + /// + /// This function returns a new OpenOptions object that you can use to + /// open or create a file with specific options if `open()` or `create()` + /// are not appropriate. + /// + /// It is equivalent to `OpenOptions::new()`, but allows you to write more + /// readable code. Instead of + /// `OpenOptions::new().append(true).open("example.log")`, + /// you can write `File::options().append(true).open("example.log")`. This + /// also avoids the need to import `OpenOptions`. + /// + /// See the [`OpenOptions::new`] function for more details. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::options().append(true).open("example.log")?; + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "with_options", since = "1.58.0")] + pub fn options() -> OpenOptions { + OpenOptions::new() + } + + /// Attempts to sync all OS-internal metadata to disk. + /// + /// This function will attempt to ensure that all in-memory data reaches the + /// filesystem before returning. + /// + /// This can be used to handle errors that would otherwise only be caught + /// when the `File` is closed. Dropping a file will ignore errors in + /// synchronizing this in-memory data. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// use std::io::prelude::*; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::create("foo.txt")?; + /// f.write_all(b"Hello, world!")?; + /// + /// f.sync_all()?; + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn sync_all(&self) -> io::Result<()> { + self.inner.fsync() + } + + /// This function is similar to [`sync_all`], except that it might not + /// synchronize file metadata to the filesystem. + /// + /// This is intended for use cases that must synchronize content, but don't + /// need the metadata on disk. The goal of this method is to reduce disk + /// operations. + /// + /// Note that some platforms may simply implement this in terms of + /// [`sync_all`]. + /// + /// [`sync_all`]: File::sync_all + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// use std::io::prelude::*; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::create("foo.txt")?; + /// f.write_all(b"Hello, world!")?; + /// + /// f.sync_data()?; + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn sync_data(&self) -> io::Result<()> { + self.inner.datasync() + } + + /// Truncates or extends the underlying file, updating the size of + /// this file to become `size`. + /// + /// If the `size` is less than the current file's size, then the file will + /// be shrunk. If it is greater than the current file's size, then the file + /// will be extended to `size` and have all of the intermediate data filled + /// in with 0s. + /// + /// The file's cursor isn't changed. In particular, if the cursor was at the + /// end and the file is shrunk using this operation, the cursor will now be + /// past the end. + /// + /// # Errors + /// + /// This function will return an error if the file is not opened for writing. + /// Also, std::io::ErrorKind::InvalidInput will be returned if the desired + /// length would cause an overflow due to the implementation specifics. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::create("foo.txt")?; + /// f.set_len(10)?; + /// Ok(()) + /// } + /// ``` + /// + /// Note that this method alters the content of the underlying file, even + /// though it takes `&self` rather than `&mut self`. + #[stable(feature = "rust1", since = "1.0.0")] + pub fn set_len(&self, size: u64) -> io::Result<()> { + self.inner.truncate(size) + } + + /// Queries metadata about the underlying file. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::open("foo.txt")?; + /// let metadata = f.metadata()?; + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn metadata(&self) -> io::Result<Metadata> { + self.inner.file_attr().map(Metadata) + } + + /// Creates a new `File` instance that shares the same underlying file handle + /// as the existing `File` instance. Reads, writes, and seeks will affect + /// both `File` instances simultaneously. + /// + /// # Examples + /// + /// Creates two handles for a file named `foo.txt`: + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut file = File::open("foo.txt")?; + /// let file_copy = file.try_clone()?; + /// Ok(()) + /// } + /// ``` + /// + /// Assuming there’s a file named `foo.txt` with contents `abcdef\n`, create + /// two handles, seek one of them, and read the remaining bytes from the + /// other handle: + /// + /// ```no_run + /// use std::fs::File; + /// use std::io::SeekFrom; + /// use std::io::prelude::*; + /// + /// fn main() -> std::io::Result<()> { + /// let mut file = File::open("foo.txt")?; + /// let mut file_copy = file.try_clone()?; + /// + /// file.seek(SeekFrom::Start(3))?; + /// + /// let mut contents = vec![]; + /// file_copy.read_to_end(&mut contents)?; + /// assert_eq!(contents, b"def\n"); + /// Ok(()) + /// } + /// ``` + #[stable(feature = "file_try_clone", since = "1.9.0")] + pub fn try_clone(&self) -> io::Result<File> { + Ok(File { inner: self.inner.duplicate()? }) + } + + /// Changes the permissions on the underlying file. + /// + /// # Platform-specific behavior + /// + /// This function currently corresponds to the `fchmod` function on Unix and + /// the `SetFileInformationByHandle` function on Windows. Note that, this + /// [may change in the future][changes]. + /// + /// [changes]: io#platform-specific-behavior + /// + /// # Errors + /// + /// This function will return an error if the user lacks permission change + /// attributes on the underlying file. It may also return an error in other + /// os-specific unspecified cases. + /// + /// # Examples + /// + /// ```no_run + /// fn main() -> std::io::Result<()> { + /// use std::fs::File; + /// + /// let file = File::open("foo.txt")?; + /// let mut perms = file.metadata()?.permissions(); + /// perms.set_readonly(true); + /// file.set_permissions(perms)?; + /// Ok(()) + /// } + /// ``` + /// + /// Note that this method alters the permissions of the underlying file, + /// even though it takes `&self` rather than `&mut self`. + #[stable(feature = "set_permissions_atomic", since = "1.16.0")] + pub fn set_permissions(&self, perm: Permissions) -> io::Result<()> { + self.inner.set_permissions(perm.0) + } + + /// Changes the timestamps of the underlying file. + /// + /// # Platform-specific behavior + /// + /// This function currently corresponds to the `futimens` function on Unix (falling back to + /// `futimes` on macOS before 10.13) and the `SetFileTime` function on Windows. Note that this + /// [may change in the future][changes]. + /// + /// [changes]: io#platform-specific-behavior + /// + /// # Errors + /// + /// This function will return an error if the user lacks permission to change timestamps on the + /// underlying file. It may also return an error in other os-specific unspecified cases. + /// + /// This function may return an error if the operating system lacks support to change one or + /// more of the timestamps set in the `FileTimes` structure. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(file_set_times)] + /// + /// fn main() -> std::io::Result<()> { + /// use std::fs::{self, File, FileTimes}; + /// + /// let src = fs::metadata("src")?; + /// let dest = File::options().write(true).open("dest")?; + /// let times = FileTimes::new() + /// .set_accessed(src.accessed()?) + /// .set_modified(src.modified()?); + /// dest.set_times(times)?; + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "file_set_times", issue = "98245")] + #[doc(alias = "futimens")] + #[doc(alias = "futimes")] + #[doc(alias = "SetFileTime")] + pub fn set_times(&self, times: FileTimes) -> io::Result<()> { + self.inner.set_times(times.0) + } + + /// Changes the modification time of the underlying file. + /// + /// This is an alias for `set_times(FileTimes::new().set_modified(time))`. + #[unstable(feature = "file_set_times", issue = "98245")] + #[inline] + pub fn set_modified(&self, time: SystemTime) -> io::Result<()> { + self.set_times(FileTimes::new().set_modified(time)) + } +} + +// In addition to the `impl`s here, `File` also has `impl`s for +// `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and +// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and +// `AsHandle`/`From<OwnedHandle>`/`Into<OwnedHandle>` and +// `AsRawHandle`/`IntoRawHandle`/`FromRawHandle` on Windows. + +impl AsInner<fs_imp::File> for File { + fn as_inner(&self) -> &fs_imp::File { + &self.inner + } +} +impl FromInner<fs_imp::File> for File { + fn from_inner(f: fs_imp::File) -> File { + File { inner: f } + } +} +impl IntoInner<fs_imp::File> for File { + fn into_inner(self) -> fs_imp::File { + self.inner + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl fmt::Debug for File { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.inner.fmt(f) + } +} + +/// Indicates how much extra capacity is needed to read the rest of the file. +fn buffer_capacity_required(mut file: &File) -> usize { + let size = file.metadata().map(|m| m.len()).unwrap_or(0); + let pos = file.stream_position().unwrap_or(0); + // Don't worry about `usize` overflow because reading will fail regardless + // in that case. + size.saturating_sub(pos) as usize +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Read for File { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + self.inner.read(buf) + } + + fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + self.inner.read_vectored(bufs) + } + + fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> { + self.inner.read_buf(buf) + } + + #[inline] + fn is_read_vectored(&self) -> bool { + self.inner.is_read_vectored() + } + + // Reserves space in the buffer based on the file size when available. + fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { + buf.reserve(buffer_capacity_required(self)); + io::default_read_to_end(self, buf) + } + + // Reserves space in the buffer based on the file size when available. + fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> { + buf.reserve(buffer_capacity_required(self)); + io::default_read_to_string(self, buf) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Write for File { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.inner.write(buf) + } + + fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + self.inner.write_vectored(bufs) + } + + #[inline] + fn is_write_vectored(&self) -> bool { + self.inner.is_write_vectored() + } + + fn flush(&mut self) -> io::Result<()> { + self.inner.flush() + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Seek for File { + fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> { + self.inner.seek(pos) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Read for &File { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + self.inner.read(buf) + } + + fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> { + self.inner.read_buf(buf) + } + + fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + self.inner.read_vectored(bufs) + } + + #[inline] + fn is_read_vectored(&self) -> bool { + self.inner.is_read_vectored() + } + + // Reserves space in the buffer based on the file size when available. + fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { + buf.reserve(buffer_capacity_required(self)); + io::default_read_to_end(self, buf) + } + + // Reserves space in the buffer based on the file size when available. + fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> { + buf.reserve(buffer_capacity_required(self)); + io::default_read_to_string(self, buf) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Write for &File { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.inner.write(buf) + } + + fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + self.inner.write_vectored(bufs) + } + + #[inline] + fn is_write_vectored(&self) -> bool { + self.inner.is_write_vectored() + } + + fn flush(&mut self) -> io::Result<()> { + self.inner.flush() + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl Seek for &File { + fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> { + self.inner.seek(pos) + } +} + +impl OpenOptions { + /// Creates a blank new set of options ready for configuration. + /// + /// All options are initially set to `false`. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let mut options = OpenOptions::new(); + /// let file = options.read(true).open("foo.txt"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] + pub fn new() -> Self { + OpenOptions(fs_imp::OpenOptions::new()) + } + + /// Sets the option for read access. + /// + /// This option, when true, will indicate that the file should be + /// `read`-able if opened. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().read(true).open("foo.txt"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn read(&mut self, read: bool) -> &mut Self { + self.0.read(read); + self + } + + /// Sets the option for write access. + /// + /// This option, when true, will indicate that the file should be + /// `write`-able if opened. + /// + /// If the file already exists, any write calls on it will overwrite its + /// contents, without truncating it. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().write(true).open("foo.txt"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn write(&mut self, write: bool) -> &mut Self { + self.0.write(write); + self + } + + /// Sets the option for the append mode. + /// + /// This option, when true, means that writes will append to a file instead + /// of overwriting previous contents. + /// Note that setting `.write(true).append(true)` has the same effect as + /// setting only `.append(true)`. + /// + /// For most filesystems, the operating system guarantees that all writes are + /// atomic: no writes get mangled because another process writes at the same + /// time. + /// + /// One maybe obvious note when using append-mode: make sure that all data + /// that belongs together is written to the file in one operation. This + /// can be done by concatenating strings before passing them to [`write()`], + /// or using a buffered writer (with a buffer of adequate size), + /// and calling [`flush()`] when the message is complete. + /// + /// If a file is opened with both read and append access, beware that after + /// opening, and after every write, the position for reading may be set at the + /// end of the file. So, before writing, save the current position (using + /// <code>[seek]\([SeekFrom]::[Current]\(0))</code>), and restore it before the next read. + /// + /// ## Note + /// + /// This function doesn't create the file if it doesn't exist. Use the + /// [`OpenOptions::create`] method to do so. + /// + /// [`write()`]: Write::write "io::Write::write" + /// [`flush()`]: Write::flush "io::Write::flush" + /// [seek]: Seek::seek "io::Seek::seek" + /// [Current]: SeekFrom::Current "io::SeekFrom::Current" + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().append(true).open("foo.txt"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn append(&mut self, append: bool) -> &mut Self { + self.0.append(append); + self + } + + /// Sets the option for truncating a previous file. + /// + /// If a file is successfully opened with this option set it will truncate + /// the file to 0 length if it already exists. + /// + /// The file must be opened with write access for truncate to work. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().write(true).truncate(true).open("foo.txt"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn truncate(&mut self, truncate: bool) -> &mut Self { + self.0.truncate(truncate); + self + } + + /// Sets the option to create a new file, or open it if it already exists. + /// + /// In order for the file to be created, [`OpenOptions::write`] or + /// [`OpenOptions::append`] access must be used. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().write(true).create(true).open("foo.txt"); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn create(&mut self, create: bool) -> &mut Self { + self.0.create(create); + self + } + + /// Sets the option to create a new file, failing if it already exists. + /// + /// No file is allowed to exist at the target location, also no (dangling) symlink. In this + /// way, if the call succeeds, the file returned is guaranteed to be new. + /// + /// This option is useful because it is atomic. Otherwise between checking + /// whether a file exists and creating a new one, the file may have been + /// created by another process (a TOCTOU race condition / attack). + /// + /// If `.create_new(true)` is set, [`.create()`] and [`.truncate()`] are + /// ignored. + /// + /// The file must be opened with write or append access in order to create + /// a new file. + /// + /// [`.create()`]: OpenOptions::create + /// [`.truncate()`]: OpenOptions::truncate + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().write(true) + /// .create_new(true) + /// .open("foo.txt"); + /// ``` + #[stable(feature = "expand_open_options2", since = "1.9.0")] + pub fn create_new(&mut self, create_new: bool) -> &mut Self { + self.0.create_new(create_new); + self + } + + /// Opens a file at `path` with the options specified by `self`. + /// + /// # Errors + /// + /// This function will return an error under a number of different + /// circumstances. Some of these error conditions are listed here, together + /// with their [`io::ErrorKind`]. The mapping to [`io::ErrorKind`]s is not + /// part of the compatibility contract of the function. + /// + /// * [`NotFound`]: The specified file does not exist and neither `create` + /// or `create_new` is set. + /// * [`NotFound`]: One of the directory components of the file path does + /// not exist. + /// * [`PermissionDenied`]: The user lacks permission to get the specified + /// access rights for the file. + /// * [`PermissionDenied`]: The user lacks permission to open one of the + /// directory components of the specified path. + /// * [`AlreadyExists`]: `create_new` was specified and the file already + /// exists. + /// * [`InvalidInput`]: Invalid combinations of open options (truncate + /// without write access, no access mode set, etc.). + /// + /// The following errors don't match any existing [`io::ErrorKind`] at the moment: + /// * One of the directory components of the specified file path + /// was not, in fact, a directory. + /// * Filesystem-level errors: full disk, write permission + /// requested on a read-only file system, exceeded disk quota, too many + /// open files, too long filename, too many symbolic links in the + /// specified path (Unix-like systems only), etc. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::OpenOptions; + /// + /// let file = OpenOptions::new().read(true).open("foo.txt"); + /// ``` + /// + /// [`AlreadyExists`]: io::ErrorKind::AlreadyExists + /// [`InvalidInput`]: io::ErrorKind::InvalidInput + /// [`NotFound`]: io::ErrorKind::NotFound + /// [`PermissionDenied`]: io::ErrorKind::PermissionDenied + #[stable(feature = "rust1", since = "1.0.0")] + pub fn open<P: AsRef<Path>>(&self, path: P) -> io::Result<File> { + self._open(path.as_ref()) + } + + fn _open(&self, path: &Path) -> io::Result<File> { + fs_imp::File::open(path, &self.0).map(|inner| File { inner }) + } +} + +impl AsInner<fs_imp::OpenOptions> for OpenOptions { + fn as_inner(&self) -> &fs_imp::OpenOptions { + &self.0 + } +} + +impl AsInnerMut<fs_imp::OpenOptions> for OpenOptions { + fn as_inner_mut(&mut self) -> &mut fs_imp::OpenOptions { + &mut self.0 + } +} + +impl Metadata { + /// Returns the file type for this metadata. + /// + /// # Examples + /// + /// ```no_run + /// fn main() -> std::io::Result<()> { + /// use std::fs; + /// + /// let metadata = fs::metadata("foo.txt")?; + /// + /// println!("{:?}", metadata.file_type()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "file_type", since = "1.1.0")] + pub fn file_type(&self) -> FileType { + FileType(self.0.file_type()) + } + + /// Returns `true` if this metadata is for a directory. The + /// result is mutually exclusive to the result of + /// [`Metadata::is_file`], and will be false for symlink metadata + /// obtained from [`symlink_metadata`]. + /// + /// # Examples + /// + /// ```no_run + /// fn main() -> std::io::Result<()> { + /// use std::fs; + /// + /// let metadata = fs::metadata("foo.txt")?; + /// + /// assert!(!metadata.is_dir()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn is_dir(&self) -> bool { + self.file_type().is_dir() + } + + /// Returns `true` if this metadata is for a regular file. The + /// result is mutually exclusive to the result of + /// [`Metadata::is_dir`], and will be false for symlink metadata + /// obtained from [`symlink_metadata`]. + /// + /// 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 [`File::open`] or + /// [`OpenOptions::open`] for more information. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::metadata("foo.txt")?; + /// + /// assert!(metadata.is_file()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn is_file(&self) -> bool { + self.file_type().is_file() + } + + /// Returns `true` if this metadata is for a symbolic link. + /// + /// # Examples + /// + #[cfg_attr(unix, doc = "```no_run")] + #[cfg_attr(not(unix), doc = "```ignore")] + /// use std::fs; + /// use std::path::Path; + /// use std::os::unix::fs::symlink; + /// + /// fn main() -> std::io::Result<()> { + /// let link_path = Path::new("link"); + /// symlink("/origin_does_not_exist/", link_path)?; + /// + /// let metadata = fs::symlink_metadata(link_path)?; + /// + /// assert!(metadata.is_symlink()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "is_symlink", since = "1.58.0")] + pub fn is_symlink(&self) -> bool { + self.file_type().is_symlink() + } + + /// Returns the size of the file, in bytes, this metadata is for. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::metadata("foo.txt")?; + /// + /// assert_eq!(0, metadata.len()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn len(&self) -> u64 { + self.0.size() + } + + /// Returns the permissions of the file this metadata is for. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::metadata("foo.txt")?; + /// + /// assert!(!metadata.permissions().readonly()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn permissions(&self) -> Permissions { + Permissions(self.0.perm()) + } + + /// Returns the last modification time listed in this metadata. + /// + /// The returned value corresponds to the `mtime` field of `stat` on Unix + /// platforms and the `ftLastWriteTime` field on Windows platforms. + /// + /// # Errors + /// + /// This field might not be available on all platforms, and will return an + /// `Err` on platforms where it is not available. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::metadata("foo.txt")?; + /// + /// if let Ok(time) = metadata.modified() { + /// println!("{time:?}"); + /// } else { + /// println!("Not supported on this platform"); + /// } + /// Ok(()) + /// } + /// ``` + #[stable(feature = "fs_time", since = "1.10.0")] + pub fn modified(&self) -> io::Result<SystemTime> { + self.0.modified().map(FromInner::from_inner) + } + + /// Returns the last access time of this metadata. + /// + /// The returned value corresponds to the `atime` field of `stat` on Unix + /// platforms and the `ftLastAccessTime` field on Windows platforms. + /// + /// Note that not all platforms will keep this field update in a file's + /// metadata, for example Windows has an option to disable updating this + /// time when files are accessed and Linux similarly has `noatime`. + /// + /// # Errors + /// + /// This field might not be available on all platforms, and will return an + /// `Err` on platforms where it is not available. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::metadata("foo.txt")?; + /// + /// if let Ok(time) = metadata.accessed() { + /// println!("{time:?}"); + /// } else { + /// println!("Not supported on this platform"); + /// } + /// Ok(()) + /// } + /// ``` + #[stable(feature = "fs_time", since = "1.10.0")] + pub fn accessed(&self) -> io::Result<SystemTime> { + self.0.accessed().map(FromInner::from_inner) + } + + /// Returns the creation time listed in this metadata. + /// + /// The returned value corresponds to the `btime` field of `statx` on + /// Linux kernel starting from to 4.11, the `birthtime` field of `stat` on other + /// Unix platforms, and the `ftCreationTime` field on Windows platforms. + /// + /// # Errors + /// + /// This field might not be available on all platforms, and will return an + /// `Err` on platforms or filesystems where it is not available. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::metadata("foo.txt")?; + /// + /// if let Ok(time) = metadata.created() { + /// println!("{time:?}"); + /// } else { + /// println!("Not supported on this platform or filesystem"); + /// } + /// Ok(()) + /// } + /// ``` + #[stable(feature = "fs_time", since = "1.10.0")] + pub fn created(&self) -> io::Result<SystemTime> { + self.0.created().map(FromInner::from_inner) + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl fmt::Debug for Metadata { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Metadata") + .field("file_type", &self.file_type()) + .field("is_dir", &self.is_dir()) + .field("is_file", &self.is_file()) + .field("permissions", &self.permissions()) + .field("modified", &self.modified()) + .field("accessed", &self.accessed()) + .field("created", &self.created()) + .finish_non_exhaustive() + } +} + +impl AsInner<fs_imp::FileAttr> for Metadata { + fn as_inner(&self) -> &fs_imp::FileAttr { + &self.0 + } +} + +impl FromInner<fs_imp::FileAttr> for Metadata { + fn from_inner(attr: fs_imp::FileAttr) -> Metadata { + Metadata(attr) + } +} + +impl FileTimes { + /// Create a new `FileTimes` with no times set. + /// + /// Using the resulting `FileTimes` in [`File::set_times`] will not modify any timestamps. + #[unstable(feature = "file_set_times", issue = "98245")] + pub fn new() -> Self { + Self::default() + } + + /// Set the last access time of a file. + #[unstable(feature = "file_set_times", issue = "98245")] + pub fn set_accessed(mut self, t: SystemTime) -> Self { + self.0.set_accessed(t.into_inner()); + self + } + + /// Set the last modified time of a file. + #[unstable(feature = "file_set_times", issue = "98245")] + pub fn set_modified(mut self, t: SystemTime) -> Self { + self.0.set_modified(t.into_inner()); + self + } +} + +impl Permissions { + /// Returns `true` if these permissions describe a readonly (unwritable) file. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::create("foo.txt")?; + /// let metadata = f.metadata()?; + /// + /// assert_eq!(false, metadata.permissions().readonly()); + /// Ok(()) + /// } + /// ``` + #[must_use = "call `set_readonly` to modify the readonly flag"] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn readonly(&self) -> bool { + self.0.readonly() + } + + /// Modifies the readonly flag for this set of permissions. If the + /// `readonly` argument is `true`, using the resulting `Permission` will + /// update file permissions to forbid writing. Conversely, if it's `false`, + /// using the resulting `Permission` will update file permissions to allow + /// writing. + /// + /// This operation does **not** modify the filesystem. To modify the + /// filesystem use the [`set_permissions`] function. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let f = File::create("foo.txt")?; + /// let metadata = f.metadata()?; + /// let mut permissions = metadata.permissions(); + /// + /// permissions.set_readonly(true); + /// + /// // filesystem doesn't change + /// assert_eq!(false, metadata.permissions().readonly()); + /// + /// // just this particular `permissions`. + /// assert_eq!(true, permissions.readonly()); + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn set_readonly(&mut self, readonly: bool) { + self.0.set_readonly(readonly) + } +} + +impl FileType { + /// Tests whether this file type represents a directory. The + /// result is mutually exclusive to the results of + /// [`is_file`] and [`is_symlink`]; only zero or one of these + /// tests may pass. + /// + /// [`is_file`]: FileType::is_file + /// [`is_symlink`]: FileType::is_symlink + /// + /// # Examples + /// + /// ```no_run + /// fn main() -> std::io::Result<()> { + /// use std::fs; + /// + /// let metadata = fs::metadata("foo.txt")?; + /// let file_type = metadata.file_type(); + /// + /// assert_eq!(file_type.is_dir(), false); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "file_type", since = "1.1.0")] + pub fn is_dir(&self) -> bool { + self.0.is_dir() + } + + /// Tests whether this file type represents a regular file. + /// The result is mutually exclusive to the results of + /// [`is_dir`] and [`is_symlink`]; only zero or one of these + /// tests may pass. + /// + /// 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 [`File::open`] or + /// [`OpenOptions::open`] for more information. + /// + /// [`is_dir`]: FileType::is_dir + /// [`is_symlink`]: FileType::is_symlink + /// + /// # Examples + /// + /// ```no_run + /// fn main() -> std::io::Result<()> { + /// use std::fs; + /// + /// let metadata = fs::metadata("foo.txt")?; + /// let file_type = metadata.file_type(); + /// + /// assert_eq!(file_type.is_file(), true); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "file_type", since = "1.1.0")] + pub fn is_file(&self) -> bool { + self.0.is_file() + } + + /// Tests whether this file type represents a symbolic link. + /// The result is mutually exclusive to the results of + /// [`is_dir`] and [`is_file`]; only zero or one of these + /// tests may pass. + /// + /// The underlying [`Metadata`] struct needs to be retrieved + /// with the [`fs::symlink_metadata`] function and not the + /// [`fs::metadata`] function. The [`fs::metadata`] function + /// follows symbolic links, so [`is_symlink`] would always + /// return `false` for the target file. + /// + /// [`fs::metadata`]: metadata + /// [`fs::symlink_metadata`]: symlink_metadata + /// [`is_dir`]: FileType::is_dir + /// [`is_file`]: FileType::is_file + /// [`is_symlink`]: FileType::is_symlink + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// let metadata = fs::symlink_metadata("foo.txt")?; + /// let file_type = metadata.file_type(); + /// + /// assert_eq!(file_type.is_symlink(), false); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[stable(feature = "file_type", since = "1.1.0")] + pub fn is_symlink(&self) -> bool { + self.0.is_symlink() + } +} + +impl AsInner<fs_imp::FileType> for FileType { + fn as_inner(&self) -> &fs_imp::FileType { + &self.0 + } +} + +impl FromInner<fs_imp::FilePermissions> for Permissions { + fn from_inner(f: fs_imp::FilePermissions) -> Permissions { + Permissions(f) + } +} + +impl AsInner<fs_imp::FilePermissions> for Permissions { + fn as_inner(&self) -> &fs_imp::FilePermissions { + &self.0 + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Iterator for ReadDir { + type Item = io::Result<DirEntry>; + + fn next(&mut self) -> Option<io::Result<DirEntry>> { + self.0.next().map(|entry| entry.map(DirEntry)) + } +} + +impl DirEntry { + /// Returns the full path to the file that this entry represents. + /// + /// The full path is created by joining the original path to `read_dir` + /// with the filename of this entry. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs; + /// + /// fn main() -> std::io::Result<()> { + /// for entry in fs::read_dir(".")? { + /// let dir = entry?; + /// println!("{:?}", dir.path()); + /// } + /// Ok(()) + /// } + /// ``` + /// + /// This prints output like: + /// + /// ```text + /// "./whatever.txt" + /// "./foo.html" + /// "./hello_world.rs" + /// ``` + /// + /// The exact text, of course, depends on what files you have in `.`. + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + pub fn path(&self) -> PathBuf { + self.0.path() + } + + /// Returns the metadata for the file that this entry points at. + /// + /// This function will not traverse symlinks if this entry points at a + /// symlink. To traverse symlinks use [`fs::metadata`] or [`fs::File::metadata`]. + /// + /// [`fs::metadata`]: metadata + /// [`fs::File::metadata`]: File::metadata + /// + /// # Platform-specific behavior + /// + /// On Windows this function is cheap to call (no extra system calls + /// needed), but on Unix platforms this function is the equivalent of + /// calling `symlink_metadata` on the path. + /// + /// # Examples + /// + /// ``` + /// use std::fs; + /// + /// if let Ok(entries) = fs::read_dir(".") { + /// for entry in entries { + /// if let Ok(entry) = entry { + /// // Here, `entry` is a `DirEntry`. + /// if let Ok(metadata) = entry.metadata() { + /// // Now let's show our entry's permissions! + /// println!("{:?}: {:?}", entry.path(), metadata.permissions()); + /// } else { + /// println!("Couldn't get metadata for {:?}", entry.path()); + /// } + /// } + /// } + /// } + /// ``` + #[stable(feature = "dir_entry_ext", since = "1.1.0")] + pub fn metadata(&self) -> io::Result<Metadata> { + self.0.metadata().map(Metadata) + } + + /// Returns the file type for the file that this entry points at. + /// + /// This function will not traverse symlinks if this entry points at a + /// symlink. + /// + /// # Platform-specific behavior + /// + /// On Windows and most Unix platforms this function is free (no extra + /// system calls needed), but some Unix platforms may require the equivalent + /// call to `symlink_metadata` to learn about the target file type. + /// + /// # Examples + /// + /// ``` + /// use std::fs; + /// + /// if let Ok(entries) = fs::read_dir(".") { + /// for entry in entries { + /// if let Ok(entry) = entry { + /// // Here, `entry` is a `DirEntry`. + /// if let Ok(file_type) = entry.file_type() { + /// // Now let's show our entry's file type! + /// println!("{:?}: {:?}", entry.path(), file_type); + /// } else { + /// println!("Couldn't get file type for {:?}", entry.path()); + /// } + /// } + /// } + /// } + /// ``` + #[stable(feature = "dir_entry_ext", since = "1.1.0")] + pub fn file_type(&self) -> io::Result<FileType> { + self.0.file_type().map(FileType) + } + + /// Returns the bare file name of this directory entry without any other + /// leading path component. + /// + /// # Examples + /// + /// ``` + /// use std::fs; + /// + /// if let Ok(entries) = fs::read_dir(".") { + /// for entry in entries { + /// if let Ok(entry) = entry { + /// // Here, `entry` is a `DirEntry`. + /// println!("{:?}", entry.file_name()); + /// } + /// } + /// } + /// ``` + #[must_use] + #[stable(feature = "dir_entry_ext", since = "1.1.0")] + pub fn file_name(&self) -> OsString { + self.0.file_name() + } +} + +#[stable(feature = "dir_entry_debug", since = "1.13.0")] +impl fmt::Debug for DirEntry { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("DirEntry").field(&self.path()).finish() + } +} + +impl AsInner<fs_imp::DirEntry> for DirEntry { + fn as_inner(&self) -> &fs_imp::DirEntry { + &self.0 + } +} + +/// Removes a file from the filesystem. +/// +/// Note that there is no +/// guarantee that the file is immediately deleted (e.g., depending on +/// platform, other open file descriptors may prevent immediate removal). +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `unlink` function on Unix +/// and the `DeleteFile` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `path` points to a directory. +/// * The file doesn't exist. +/// * The user lacks permissions to remove the file. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::remove_file("a.txt")?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn remove_file<P: AsRef<Path>>(path: P) -> io::Result<()> { + fs_imp::unlink(path.as_ref()) +} + +/// Given a path, query the file system to get information about a file, +/// directory, etc. +/// +/// This function will traverse symbolic links to query information about the +/// destination file. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `stat` function on Unix +/// and the `GetFileInformationByHandle` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * The user lacks permissions to perform `metadata` call on `path`. +/// * `path` does not exist. +/// +/// # Examples +/// +/// ```rust,no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// let attr = fs::metadata("/some/file/path.txt")?; +/// // inspect attr ... +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> { + fs_imp::stat(path.as_ref()).map(Metadata) +} + +/// Query the metadata about a file without following symlinks. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `lstat` function on Unix +/// and the `GetFileInformationByHandle` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * The user lacks permissions to perform `metadata` call on `path`. +/// * `path` does not exist. +/// +/// # Examples +/// +/// ```rust,no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// let attr = fs::symlink_metadata("/some/file/path.txt")?; +/// // inspect attr ... +/// Ok(()) +/// } +/// ``` +#[stable(feature = "symlink_metadata", since = "1.1.0")] +pub fn symlink_metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> { + fs_imp::lstat(path.as_ref()).map(Metadata) +} + +/// Rename a file or directory to a new name, replacing the original file if +/// `to` already exists. +/// +/// This will not work if the new name is on a different mount point. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `rename` function on Unix +/// and the `MoveFileEx` function with the `MOVEFILE_REPLACE_EXISTING` flag on Windows. +/// +/// Because of this, the behavior when both `from` and `to` exist differs. On +/// Unix, if `from` is a directory, `to` must also be an (empty) directory. If +/// `from` is not a directory, `to` must also be not a directory. In contrast, +/// on Windows, `from` can be anything, but `to` must *not* be a directory. +/// +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `from` does not exist. +/// * The user lacks permissions to view contents. +/// * `from` and `to` are on separate filesystems. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::rename("a.txt", "b.txt")?; // Rename a.txt to b.txt +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<()> { + fs_imp::rename(from.as_ref(), to.as_ref()) +} + +/// Copies the contents of one file to another. This function will also +/// copy the permission bits of the original file to the destination file. +/// +/// This function will **overwrite** the contents of `to`. +/// +/// Note that if `from` and `to` both point to the same file, then the file +/// will likely get truncated by this operation. +/// +/// On success, the total number of bytes copied is returned and it is equal to +/// the length of the `to` file as reported by `metadata`. +/// +/// If you’re wanting to copy the contents of one file to another and you’re +/// working with [`File`]s, see the [`io::copy()`] function. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `open` function in Unix +/// with `O_RDONLY` for `from` and `O_WRONLY`, `O_CREAT`, and `O_TRUNC` for `to`. +/// `O_CLOEXEC` is set for returned file descriptors. +/// +/// On Linux (including Android), this function attempts to use `copy_file_range(2)`, +/// and falls back to reading and writing if that is not possible. +/// +/// On Windows, this function currently corresponds to `CopyFileEx`. Alternate +/// NTFS streams are copied but only the size of the main stream is returned by +/// this function. +/// +/// On MacOS, this function corresponds to `fclonefileat` and `fcopyfile`. +/// +/// Note that platform-specific behavior [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `from` is neither a regular file nor a symlink to a regular file. +/// * `from` does not exist. +/// * The current process does not have the permission rights to read +/// `from` or write `to`. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::copy("foo.txt", "bar.txt")?; // Copy foo.txt to bar.txt +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn copy<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<u64> { + fs_imp::copy(from.as_ref(), to.as_ref()) +} + +/// Creates a new hard link on the filesystem. +/// +/// The `link` path will be a link pointing to the `original` path. Note that +/// systems often require these two paths to both be located on the same +/// filesystem. +/// +/// If `original` names a symbolic link, it is platform-specific whether the +/// symbolic link is followed. On platforms where it's possible to not follow +/// it, it is not followed, and the created hard link points to the symbolic +/// link itself. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds the `CreateHardLink` function on Windows. +/// On most Unix systems, it corresponds to the `linkat` function with no flags. +/// On Android, VxWorks, and Redox, it instead corresponds to the `link` function. +/// On MacOS, it uses the `linkat` function if it is available, but on very old +/// systems where `linkat` is not available, `link` is selected at runtime instead. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * The `original` path is not a file or doesn't exist. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::hard_link("a.txt", "b.txt")?; // Hard link a.txt to b.txt +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn hard_link<P: AsRef<Path>, Q: AsRef<Path>>(original: P, link: Q) -> io::Result<()> { + fs_imp::link(original.as_ref(), link.as_ref()) +} + +/// Creates a new symbolic link on the filesystem. +/// +/// The `link` path will be a symbolic link pointing to the `original` path. +/// On Windows, this will be a file symlink, not a directory symlink; +/// for this reason, the platform-specific [`std::os::unix::fs::symlink`] +/// and [`std::os::windows::fs::symlink_file`] or [`symlink_dir`] should be +/// used instead to make the intent explicit. +/// +/// [`std::os::unix::fs::symlink`]: crate::os::unix::fs::symlink +/// [`std::os::windows::fs::symlink_file`]: crate::os::windows::fs::symlink_file +/// [`symlink_dir`]: crate::os::windows::fs::symlink_dir +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::soft_link("a.txt", "b.txt")?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +#[deprecated( + since = "1.1.0", + note = "replaced with std::os::unix::fs::symlink and \ + std::os::windows::fs::{symlink_file, symlink_dir}" +)] +pub fn soft_link<P: AsRef<Path>, Q: AsRef<Path>>(original: P, link: Q) -> io::Result<()> { + fs_imp::symlink(original.as_ref(), link.as_ref()) +} + +/// Reads a symbolic link, returning the file that the link points to. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `readlink` function on Unix +/// and the `CreateFile` function with `FILE_FLAG_OPEN_REPARSE_POINT` and +/// `FILE_FLAG_BACKUP_SEMANTICS` flags on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `path` is not a symbolic link. +/// * `path` does not exist. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// let path = fs::read_link("a.txt")?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn read_link<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> { + fs_imp::readlink(path.as_ref()) +} + +/// Returns the canonical, absolute form of a path with all intermediate +/// components normalized and symbolic links resolved. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `realpath` function on Unix +/// and the `CreateFile` and `GetFinalPathNameByHandle` functions on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// On Windows, this converts the path to use [extended length path][path] +/// syntax, which allows your program to use longer path names, but means you +/// can only join backslash-delimited paths to it, and it may be incompatible +/// with other applications (if passed to the application on the command-line, +/// or written to a file another application may read). +/// +/// [changes]: io#platform-specific-behavior +/// [path]: https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `path` does not exist. +/// * A non-final component in path is not a directory. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// let path = fs::canonicalize("../a/../foo.txt")?; +/// Ok(()) +/// } +/// ``` +#[doc(alias = "realpath")] +#[doc(alias = "GetFinalPathNameByHandle")] +#[stable(feature = "fs_canonicalize", since = "1.5.0")] +pub fn canonicalize<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> { + fs_imp::canonicalize(path.as_ref()) +} + +/// Creates a new, empty directory at the provided path +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `mkdir` function on Unix +/// and the `CreateDirectory` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// **NOTE**: If a parent of the given path doesn't exist, this function will +/// return an error. To create a directory and all its missing parents at the +/// same time, use the [`create_dir_all`] function. +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * User lacks permissions to create directory at `path`. +/// * A parent of the given path doesn't exist. (To create a directory and all +/// its missing parents at the same time, use the [`create_dir_all`] +/// function.) +/// * `path` already exists. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::create_dir("/some/dir")?; +/// Ok(()) +/// } +/// ``` +#[doc(alias = "mkdir")] +#[stable(feature = "rust1", since = "1.0.0")] +pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> { + DirBuilder::new().create(path.as_ref()) +} + +/// Recursively create a directory and all of its parent components if they +/// are missing. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `mkdir` function on Unix +/// and the `CreateDirectory` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * If any directory in the path specified by `path` +/// does not already exist and it could not be created otherwise. The specific +/// error conditions for when a directory is being created (after it is +/// determined to not exist) are outlined by [`fs::create_dir`]. +/// +/// Notable exception is made for situations where any of the directories +/// specified in the `path` could not be created as it was being created concurrently. +/// Such cases are considered to be successful. That is, calling `create_dir_all` +/// concurrently from multiple threads or processes is guaranteed not to fail +/// due to a race condition with itself. +/// +/// [`fs::create_dir`]: create_dir +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::create_dir_all("/some/dir")?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn create_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> { + DirBuilder::new().recursive(true).create(path.as_ref()) +} + +/// Removes an empty directory. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `rmdir` function on Unix +/// and the `RemoveDirectory` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `path` doesn't exist. +/// * `path` isn't a directory. +/// * The user lacks permissions to remove the directory at the provided `path`. +/// * The directory isn't empty. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::remove_dir("/some/dir")?; +/// Ok(()) +/// } +/// ``` +#[doc(alias = "rmdir")] +#[stable(feature = "rust1", since = "1.0.0")] +pub fn remove_dir<P: AsRef<Path>>(path: P) -> io::Result<()> { + fs_imp::rmdir(path.as_ref()) +} + +/// Removes a directory at this path, after removing all its contents. Use +/// carefully! +/// +/// This function does **not** follow symbolic links and it will simply remove the +/// symbolic link itself. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to `openat`, `fdopendir`, `unlinkat` and `lstat` functions +/// on Unix (except for macOS before version 10.10 and REDOX) and the `CreateFileW`, +/// `GetFileInformationByHandleEx`, `SetFileInformationByHandle`, and `NtCreateFile` functions on +/// Windows. Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// On macOS before version 10.10 and REDOX, as well as when running in Miri for any target, this +/// function is not protected against time-of-check to time-of-use (TOCTOU) race conditions, and +/// should not be used in security-sensitive code on those platforms. All other platforms are +/// protected. +/// +/// # Errors +/// +/// See [`fs::remove_file`] and [`fs::remove_dir`]. +/// +/// [`fs::remove_file`]: remove_file +/// [`fs::remove_dir`]: remove_dir +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// fs::remove_dir_all("/some/dir")?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn remove_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> { + fs_imp::remove_dir_all(path.as_ref()) +} + +/// Returns an iterator over the entries within a directory. +/// +/// The iterator will yield instances of <code>[io::Result]<[DirEntry]></code>. +/// New errors may be encountered after an iterator is initially constructed. +/// Entries for the current and parent directories (typically `.` and `..`) are +/// skipped. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `opendir` function on Unix +/// and the `FindFirstFile` function on Windows. Advancing the iterator +/// currently corresponds to `readdir` on Unix and `FindNextFile` on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// The order in which this iterator returns entries is platform and filesystem +/// dependent. +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * The provided `path` doesn't exist. +/// * The process lacks permissions to view the contents. +/// * The `path` points at a non-directory file. +/// +/// # Examples +/// +/// ``` +/// use std::io; +/// use std::fs::{self, DirEntry}; +/// use std::path::Path; +/// +/// // one possible implementation of walking a directory only visiting files +/// fn visit_dirs(dir: &Path, cb: &dyn Fn(&DirEntry)) -> io::Result<()> { +/// if dir.is_dir() { +/// for entry in fs::read_dir(dir)? { +/// let entry = entry?; +/// let path = entry.path(); +/// if path.is_dir() { +/// visit_dirs(&path, cb)?; +/// } else { +/// cb(&entry); +/// } +/// } +/// } +/// Ok(()) +/// } +/// ``` +/// +/// ```rust,no_run +/// use std::{fs, io}; +/// +/// fn main() -> io::Result<()> { +/// let mut entries = fs::read_dir(".")? +/// .map(|res| res.map(|e| e.path())) +/// .collect::<Result<Vec<_>, io::Error>>()?; +/// +/// // The order in which `read_dir` returns entries is not guaranteed. If reproducible +/// // ordering is required the entries should be explicitly sorted. +/// +/// entries.sort(); +/// +/// // The entries have now been sorted by their path. +/// +/// Ok(()) +/// } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn read_dir<P: AsRef<Path>>(path: P) -> io::Result<ReadDir> { + fs_imp::readdir(path.as_ref()).map(ReadDir) +} + +/// Changes the permissions found on a file or a directory. +/// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `chmod` function on Unix +/// and the `SetFileAttributes` function on Windows. +/// Note that, this [may change in the future][changes]. +/// +/// [changes]: io#platform-specific-behavior +/// +/// # Errors +/// +/// This function will return an error in the following situations, but is not +/// limited to just these cases: +/// +/// * `path` does not exist. +/// * The user lacks the permission to change attributes of the file. +/// +/// # Examples +/// +/// ```no_run +/// use std::fs; +/// +/// fn main() -> std::io::Result<()> { +/// let mut perms = fs::metadata("foo.txt")?.permissions(); +/// perms.set_readonly(true); +/// fs::set_permissions("foo.txt", perms)?; +/// Ok(()) +/// } +/// ``` +#[stable(feature = "set_permissions", since = "1.1.0")] +pub fn set_permissions<P: AsRef<Path>>(path: P, perm: Permissions) -> io::Result<()> { + fs_imp::set_perm(path.as_ref(), perm.0) +} + +impl DirBuilder { + /// Creates a new set of options with default mode/security settings for all + /// platforms and also non-recursive. + /// + /// # Examples + /// + /// ``` + /// use std::fs::DirBuilder; + /// + /// let builder = DirBuilder::new(); + /// ``` + #[stable(feature = "dir_builder", since = "1.6.0")] + #[must_use] + pub fn new() -> DirBuilder { + DirBuilder { inner: fs_imp::DirBuilder::new(), recursive: false } + } + + /// Indicates that directories should be created recursively, creating all + /// parent directories. Parents that do not exist are created with the same + /// security and permissions settings. + /// + /// This option defaults to `false`. + /// + /// # Examples + /// + /// ``` + /// use std::fs::DirBuilder; + /// + /// let mut builder = DirBuilder::new(); + /// builder.recursive(true); + /// ``` + #[stable(feature = "dir_builder", since = "1.6.0")] + pub fn recursive(&mut self, recursive: bool) -> &mut Self { + self.recursive = recursive; + self + } + + /// Creates the specified directory with the options configured in this + /// builder. + /// + /// It is considered an error if the directory already exists unless + /// recursive mode is enabled. + /// + /// # Examples + /// + /// ```no_run + /// use std::fs::{self, DirBuilder}; + /// + /// let path = "/tmp/foo/bar/baz"; + /// DirBuilder::new() + /// .recursive(true) + /// .create(path).unwrap(); + /// + /// assert!(fs::metadata(path).unwrap().is_dir()); + /// ``` + #[stable(feature = "dir_builder", since = "1.6.0")] + pub fn create<P: AsRef<Path>>(&self, path: P) -> io::Result<()> { + self._create(path.as_ref()) + } + + fn _create(&self, path: &Path) -> io::Result<()> { + if self.recursive { self.create_dir_all(path) } else { self.inner.mkdir(path) } + } + + fn create_dir_all(&self, path: &Path) -> io::Result<()> { + if path == Path::new("") { + return Ok(()); + } + + match self.inner.mkdir(path) { + Ok(()) => return Ok(()), + Err(ref e) if e.kind() == io::ErrorKind::NotFound => {} + Err(_) if path.is_dir() => return Ok(()), + Err(e) => return Err(e), + } + match path.parent() { + Some(p) => self.create_dir_all(p)?, + None => { + return Err(io::const_io_error!( + io::ErrorKind::Uncategorized, + "failed to create whole tree", + )); + } + } + match self.inner.mkdir(path) { + Ok(()) => Ok(()), + Err(_) if path.is_dir() => Ok(()), + Err(e) => Err(e), + } + } +} + +impl AsInnerMut<fs_imp::DirBuilder> for DirBuilder { + fn as_inner_mut(&mut self) -> &mut fs_imp::DirBuilder { + &mut self.inner + } +} + +/// 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 [`Path::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 +/// #![feature(fs_try_exists)] +/// use std::fs; +/// +/// assert!(!fs::try_exists("does_not_exist.txt").expect("Can't check existence of file does_not_exist.txt")); +/// assert!(fs::try_exists("/root/secret_file.txt").is_err()); +/// ``` +/// +/// [`Path::exists`]: crate::path::Path::exists +// FIXME: stabilization should modify documentation of `exists()` to recommend this method +// instead. +#[unstable(feature = "fs_try_exists", issue = "83186")] +#[inline] +pub fn try_exists<P: AsRef<Path>>(path: P) -> io::Result<bool> { + fs_imp::try_exists(path.as_ref()) +} |