| /*! |
| This crate provides a safe and simple **cross platform** way to determine |
| whether two file paths refer to the same file or directory. |
| |
| Most uses of this crate should be limited to the top-level [`is_same_file`] |
| function, which takes two file paths and returns true if they refer to the |
| same file or directory: |
| |
| ```rust,no_run |
| # use std::error::Error; |
| use same_file::is_same_file; |
| |
| # fn try_main() -> Result<(), Box<Error>> { |
| assert!(is_same_file("/bin/sh", "/usr/bin/sh")?); |
| # Ok(()) |
| # } |
| # |
| # fn main() { |
| # try_main().unwrap(); |
| # } |
| ``` |
| |
| Additionally, this crate provides a [`Handle`] type that permits a more efficient |
| equality check depending on your access pattern. For example, if one wanted to |
| check whether any path in a list of paths corresponded to the process' stdout |
| handle, then one could build a handle once for stdout. The equality check for |
| each file in the list then only requires one stat call instead of two. The code |
| might look like this: |
| |
| ```rust,no_run |
| # use std::error::Error; |
| use same_file::Handle; |
| |
| # fn try_main() -> Result<(), Box<Error>> { |
| let candidates = &[ |
| "examples/is_same_file.rs", |
| "examples/is_stderr.rs", |
| "examples/stderr", |
| ]; |
| let stdout_handle = Handle::stdout()?; |
| for candidate in candidates { |
| let handle = Handle::from_path(candidate)?; |
| if stdout_handle == handle { |
| println!("{:?} is stdout!", candidate); |
| } else { |
| println!("{:?} is NOT stdout!", candidate); |
| } |
| } |
| # Ok(()) |
| # } |
| # |
| # fn main() { |
| # try_main().unwrap(); |
| # } |
| ``` |
| |
| See [`examples/is_stderr.rs`] for a runnable example and compare the output of: |
| |
| - `cargo run --example is_stderr 2> examples/stderr` and |
| - `cargo run --example is_stderr`. |
| |
| [`is_same_file`]: fn.is_same_file.html |
| [`Handle`]: struct.Handle.html |
| [`examples/is_stderr.rs`]: https://github.com/BurntSushi/same-file/blob/master/examples/is_same_file.rs |
| |
| */ |
| |
| #![allow(bare_trait_objects, unknown_lints)] |
| #![deny(missing_docs)] |
| |
| #[cfg(test)] |
| doc_comment::doctest!("../README.md"); |
| |
| use std::fs::File; |
| use std::io; |
| use std::path::Path; |
| |
| #[cfg(any(target_os = "redox", unix))] |
| use crate::unix as imp; |
| #[cfg(not(any(target_os = "redox", unix, windows)))] |
| use unknown as imp; |
| #[cfg(windows)] |
| use win as imp; |
| |
| #[cfg(any(target_os = "redox", unix))] |
| mod unix; |
| #[cfg(not(any(target_os = "redox", unix, windows)))] |
| mod unknown; |
| #[cfg(windows)] |
| mod win; |
| |
| /// A handle to a file that can be tested for equality with other handles. |
| /// |
| /// If two files are the same, then any two handles of those files will compare |
| /// equal. If two files are not the same, then any two handles of those files |
| /// will compare not-equal. |
| /// |
| /// A handle consumes an open file resource as long as it exists. |
| /// |
| /// Equality is determined by comparing inode numbers on Unix and a combination |
| /// of identifier, volume serial, and file size on Windows. Note that it's |
| /// possible for comparing two handles to produce a false positive on some |
| /// platforms. Namely, two handles can compare equal even if the two handles |
| /// *don't* point to the same file. Check the [source] for specific |
| /// implementation details. |
| /// |
| /// [source]: https://github.com/BurntSushi/same-file/tree/master/src |
| #[derive(Debug, Eq, PartialEq, Hash)] |
| pub struct Handle(imp::Handle); |
| |
| impl Handle { |
| /// Construct a handle from a path. |
| /// |
| /// Note that the underlying [`File`] is opened in read-only mode on all |
| /// platforms. |
| /// |
| /// [`File`]: https://doc.rust-lang.org/std/fs/struct.File.html |
| /// |
| /// # Errors |
| /// This method will return an [`io::Error`] if the path cannot |
| /// be opened, or the file's metadata cannot be obtained. |
| /// The most common reasons for this are: the path does not |
| /// exist, or there were not enough permissions. |
| /// |
| /// [`io::Error`]: https://doc.rust-lang.org/std/io/struct.Error.html |
| /// |
| /// # Examples |
| /// Check that two paths are not the same file: |
| /// |
| /// ```rust,no_run |
| /// # use std::error::Error; |
| /// use same_file::Handle; |
| /// |
| /// # fn try_main() -> Result<(), Box<Error>> { |
| /// let source = Handle::from_path("./source")?; |
| /// let target = Handle::from_path("./target")?; |
| /// assert_ne!(source, target, "The files are the same."); |
| /// # Ok(()) |
| /// # } |
| /// # |
| /// # fn main() { |
| /// # try_main().unwrap(); |
| /// # } |
| /// ``` |
| pub fn from_path<P: AsRef<Path>>(p: P) -> io::Result<Handle> { |
| imp::Handle::from_path(p).map(Handle) |
| } |
| |
| /// Construct a handle from a file. |
| /// |
| /// # Errors |
| /// This method will return an [`io::Error`] if the metadata for |
| /// the given [`File`] cannot be obtained. |
| /// |
| /// [`io::Error`]: https://doc.rust-lang.org/std/io/struct.Error.html |
| /// [`File`]: https://doc.rust-lang.org/std/fs/struct.File.html |
| /// |
| /// # Examples |
| /// Check that two files are not in fact the same file: |
| /// |
| /// ```rust,no_run |
| /// # use std::error::Error; |
| /// # use std::fs::File; |
| /// use same_file::Handle; |
| /// |
| /// # fn try_main() -> Result<(), Box<Error>> { |
| /// let source = File::open("./source")?; |
| /// let target = File::open("./target")?; |
| /// |
| /// assert_ne!( |
| /// Handle::from_file(source)?, |
| /// Handle::from_file(target)?, |
| /// "The files are the same." |
| /// ); |
| /// # Ok(()) |
| /// # } |
| /// # |
| /// # fn main() { |
| /// # try_main().unwrap(); |
| /// # } |
| /// ``` |
| pub fn from_file(file: File) -> io::Result<Handle> { |
| imp::Handle::from_file(file).map(Handle) |
| } |
| |
| /// Construct a handle from stdin. |
| /// |
| /// # Errors |
| /// This method will return an [`io::Error`] if stdin cannot |
| /// be opened due to any I/O-related reason. |
| /// |
| /// [`io::Error`]: https://doc.rust-lang.org/std/io/struct.Error.html |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// # use std::error::Error; |
| /// use same_file::Handle; |
| /// |
| /// # fn try_main() -> Result<(), Box<Error>> { |
| /// let stdin = Handle::stdin()?; |
| /// let stdout = Handle::stdout()?; |
| /// let stderr = Handle::stderr()?; |
| /// |
| /// if stdin == stdout { |
| /// println!("stdin == stdout"); |
| /// } |
| /// if stdin == stderr { |
| /// println!("stdin == stderr"); |
| /// } |
| /// if stdout == stderr { |
| /// println!("stdout == stderr"); |
| /// } |
| /// # |
| /// # Ok(()) |
| /// # } |
| /// # |
| /// # fn main() { |
| /// # try_main().unwrap(); |
| /// # } |
| /// ``` |
| /// |
| /// The output differs depending on the platform. |
| /// |
| /// On Linux: |
| /// |
| /// ```text |
| /// $ ./example |
| /// stdin == stdout |
| /// stdin == stderr |
| /// stdout == stderr |
| /// $ ./example > result |
| /// $ cat result |
| /// stdin == stderr |
| /// $ ./example > result 2>&1 |
| /// $ cat result |
| /// stdout == stderr |
| /// ``` |
| /// |
| /// Windows: |
| /// |
| /// ```text |
| /// > example |
| /// > example > result 2>&1 |
| /// > type result |
| /// stdout == stderr |
| /// ``` |
| pub fn stdin() -> io::Result<Handle> { |
| imp::Handle::stdin().map(Handle) |
| } |
| |
| /// Construct a handle from stdout. |
| /// |
| /// # Errors |
| /// This method will return an [`io::Error`] if stdout cannot |
| /// be opened due to any I/O-related reason. |
| /// |
| /// [`io::Error`]: https://doc.rust-lang.org/std/io/struct.Error.html |
| /// |
| /// # Examples |
| /// See the example for [`stdin()`]. |
| /// |
| /// [`stdin()`]: #method.stdin |
| pub fn stdout() -> io::Result<Handle> { |
| imp::Handle::stdout().map(Handle) |
| } |
| |
| /// Construct a handle from stderr. |
| /// |
| /// # Errors |
| /// This method will return an [`io::Error`] if stderr cannot |
| /// be opened due to any I/O-related reason. |
| /// |
| /// [`io::Error`]: https://doc.rust-lang.org/std/io/struct.Error.html |
| /// |
| /// # Examples |
| /// See the example for [`stdin()`]. |
| /// |
| /// [`stdin()`]: #method.stdin |
| pub fn stderr() -> io::Result<Handle> { |
| imp::Handle::stderr().map(Handle) |
| } |
| |
| /// Return a reference to the underlying file. |
| /// |
| /// # Examples |
| /// Ensure that the target file is not the same as the source one, |
| /// and copy the data to it: |
| /// |
| /// ```rust,no_run |
| /// # use std::error::Error; |
| /// use std::io::prelude::*; |
| /// use std::io::Write; |
| /// use std::fs::File; |
| /// use same_file::Handle; |
| /// |
| /// # fn try_main() -> Result<(), Box<Error>> { |
| /// let source = File::open("source")?; |
| /// let target = File::create("target")?; |
| /// |
| /// let source_handle = Handle::from_file(source)?; |
| /// let mut target_handle = Handle::from_file(target)?; |
| /// assert_ne!(source_handle, target_handle, "The files are the same."); |
| /// |
| /// let mut source = source_handle.as_file(); |
| /// let target = target_handle.as_file_mut(); |
| /// |
| /// let mut buffer = Vec::new(); |
| /// // data copy is simplified for the purposes of the example |
| /// source.read_to_end(&mut buffer)?; |
| /// target.write_all(&buffer)?; |
| /// # |
| /// # Ok(()) |
| /// # } |
| /// # |
| /// # fn main() { |
| /// # try_main().unwrap(); |
| /// # } |
| /// ``` |
| pub fn as_file(&self) -> &File { |
| self.0.as_file() |
| } |
| |
| /// Return a mutable reference to the underlying file. |
| /// |
| /// # Examples |
| /// See the example for [`as_file()`]. |
| /// |
| /// [`as_file()`]: #method.as_file |
| pub fn as_file_mut(&mut self) -> &mut File { |
| self.0.as_file_mut() |
| } |
| |
| /// Return the underlying device number of this handle. |
| /// |
| /// Note that this only works on unix platforms. |
| #[cfg(any(target_os = "redox", unix))] |
| pub fn dev(&self) -> u64 { |
| self.0.dev() |
| } |
| |
| /// Return the underlying inode number of this handle. |
| /// |
| /// Note that this only works on unix platforms. |
| #[cfg(any(target_os = "redox", unix))] |
| pub fn ino(&self) -> u64 { |
| self.0.ino() |
| } |
| } |
| |
| /// Returns true if the two file paths may correspond to the same file. |
| /// |
| /// Note that it's possible for this to produce a false positive on some |
| /// platforms. Namely, this can return true even if the two file paths *don't* |
| /// resolve to the same file. |
| /// # Errors |
| /// This function will return an [`io::Error`] if any of the two paths cannot |
| /// be opened. The most common reasons for this are: the path does not exist, |
| /// or there were not enough permissions. |
| /// |
| /// [`io::Error`]: https://doc.rust-lang.org/std/io/struct.Error.html |
| /// |
| /// # Example |
| /// |
| /// ```rust,no_run |
| /// use same_file::is_same_file; |
| /// |
| /// assert!(is_same_file("./foo", "././foo").unwrap_or(false)); |
| /// ``` |
| pub fn is_same_file<P, Q>(path1: P, path2: Q) -> io::Result<bool> |
| where |
| P: AsRef<Path>, |
| Q: AsRef<Path>, |
| { |
| Ok(Handle::from_path(path1)? == Handle::from_path(path2)?) |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use std::env; |
| use std::error; |
| use std::fs::{self, File}; |
| use std::io; |
| use std::path::{Path, PathBuf}; |
| use std::result; |
| |
| use super::is_same_file; |
| |
| type Result<T> = result::Result<T, Box<error::Error + Send + Sync>>; |
| |
| /// Create an error from a format!-like syntax. |
| macro_rules! err { |
| ($($tt:tt)*) => { |
| Box::<error::Error + Send + Sync>::from(format!($($tt)*)) |
| } |
| } |
| |
| /// A simple wrapper for creating a temporary directory that is |
| /// automatically deleted when it's dropped. |
| /// |
| /// We use this in lieu of tempfile because tempfile brings in too many |
| /// dependencies. |
| #[derive(Debug)] |
| struct TempDir(PathBuf); |
| |
| impl Drop for TempDir { |
| fn drop(&mut self) { |
| fs::remove_dir_all(&self.0).unwrap(); |
| } |
| } |
| |
| impl TempDir { |
| /// Create a new empty temporary directory under the system's |
| /// configured temporary directory. |
| fn new() -> Result<TempDir> { |
| #![allow(deprecated)] |
| |
| use std::sync::atomic::{ |
| AtomicUsize, Ordering, ATOMIC_USIZE_INIT, |
| }; |
| |
| static TRIES: usize = 100; |
| static COUNTER: AtomicUsize = ATOMIC_USIZE_INIT; |
| |
| let tmpdir = env::temp_dir(); |
| for _ in 0..TRIES { |
| let count = COUNTER.fetch_add(1, Ordering::SeqCst); |
| let path = tmpdir.join("rust-walkdir").join(count.to_string()); |
| if path.is_dir() { |
| continue; |
| } |
| fs::create_dir_all(&path).map_err(|e| { |
| err!("failed to create {}: {}", path.display(), e) |
| })?; |
| return Ok(TempDir(path)); |
| } |
| Err(err!("failed to create temp dir after {} tries", TRIES)) |
| } |
| |
| /// Return the underlying path to this temporary directory. |
| fn path(&self) -> &Path { |
| &self.0 |
| } |
| } |
| |
| fn tmpdir() -> TempDir { |
| TempDir::new().unwrap() |
| } |
| |
| #[cfg(unix)] |
| pub fn soft_link_dir<P: AsRef<Path>, Q: AsRef<Path>>( |
| src: P, |
| dst: Q, |
| ) -> io::Result<()> { |
| use std::os::unix::fs::symlink; |
| symlink(src, dst) |
| } |
| |
| #[cfg(unix)] |
| pub fn soft_link_file<P: AsRef<Path>, Q: AsRef<Path>>( |
| src: P, |
| dst: Q, |
| ) -> io::Result<()> { |
| soft_link_dir(src, dst) |
| } |
| |
| #[cfg(windows)] |
| pub fn soft_link_dir<P: AsRef<Path>, Q: AsRef<Path>>( |
| src: P, |
| dst: Q, |
| ) -> io::Result<()> { |
| use std::os::windows::fs::symlink_dir; |
| symlink_dir(src, dst) |
| } |
| |
| #[cfg(windows)] |
| pub fn soft_link_file<P: AsRef<Path>, Q: AsRef<Path>>( |
| src: P, |
| dst: Q, |
| ) -> io::Result<()> { |
| use std::os::windows::fs::symlink_file; |
| symlink_file(src, dst) |
| } |
| |
| // These tests are rather uninteresting. The really interesting tests |
| // would stress the edge cases. On Unix, this might be comparing two files |
| // on different mount points with the same inode number. On Windows, this |
| // might be comparing two files whose file indices are the same on file |
| // systems where such things aren't guaranteed to be unique. |
| // |
| // Alas, I don't know how to create those environmental conditions. ---AG |
| |
| #[test] |
| fn same_file_trivial() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| File::create(dir.join("a")).unwrap(); |
| assert!(is_same_file(dir.join("a"), dir.join("a")).unwrap()); |
| } |
| |
| #[test] |
| fn same_dir_trivial() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| fs::create_dir(dir.join("a")).unwrap(); |
| assert!(is_same_file(dir.join("a"), dir.join("a")).unwrap()); |
| } |
| |
| #[test] |
| fn not_same_file_trivial() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| File::create(dir.join("a")).unwrap(); |
| File::create(dir.join("b")).unwrap(); |
| assert!(!is_same_file(dir.join("a"), dir.join("b")).unwrap()); |
| } |
| |
| #[test] |
| fn not_same_dir_trivial() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| fs::create_dir(dir.join("a")).unwrap(); |
| fs::create_dir(dir.join("b")).unwrap(); |
| assert!(!is_same_file(dir.join("a"), dir.join("b")).unwrap()); |
| } |
| |
| #[test] |
| fn same_file_hard() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| File::create(dir.join("a")).unwrap(); |
| fs::hard_link(dir.join("a"), dir.join("alink")).unwrap(); |
| assert!(is_same_file(dir.join("a"), dir.join("alink")).unwrap()); |
| } |
| |
| #[test] |
| fn same_file_soft() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| File::create(dir.join("a")).unwrap(); |
| soft_link_file(dir.join("a"), dir.join("alink")).unwrap(); |
| assert!(is_same_file(dir.join("a"), dir.join("alink")).unwrap()); |
| } |
| |
| #[test] |
| fn same_dir_soft() { |
| let tdir = tmpdir(); |
| let dir = tdir.path(); |
| |
| fs::create_dir(dir.join("a")).unwrap(); |
| soft_link_dir(dir.join("a"), dir.join("alink")).unwrap(); |
| assert!(is_same_file(dir.join("a"), dir.join("alink")).unwrap()); |
| } |
| |
| #[test] |
| fn test_send() { |
| fn assert_send<T: Send>() {} |
| assert_send::<super::Handle>(); |
| } |
| |
| #[test] |
| fn test_sync() { |
| fn assert_sync<T: Sync>() {} |
| assert_sync::<super::Handle>(); |
| } |
| } |