From 246f239d9f40f633160f0c18f87a20922d4e77bb Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:06:37 +0200 Subject: Merging debian version 1.65.0+dfsg1-2. Signed-off-by: Daniel Baumann --- library/std/src/fs.rs | 41 +++++++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 6 deletions(-) (limited to 'library/std/src/fs.rs') diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs index c8e131b6e..c6c78dc39 100644 --- a/library/std/src/fs.rs +++ b/library/std/src/fs.rs @@ -13,13 +13,13 @@ mod tests; use crate::ffi::OsString; use crate::fmt; -use crate::io::{self, IoSlice, IoSliceMut, Read, ReadBuf, Seek, SeekFrom, Write}; +use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read, 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 object providing access 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 @@ -377,6 +377,35 @@ impl File { OpenOptions::new().write(true).create(true).truncate(true).open(path.as_ref()) } + /// Creates a new file in read-write mode; error if the file exists. + /// + /// This function will create a file if it does not exist, or return an error if it does. 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). + /// + /// This can also be written using + /// `File::options().read(true).write(true).create_new(true).open(...)`. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(file_create_new)] + /// + /// use std::fs::File; + /// + /// fn main() -> std::io::Result<()> { + /// let mut f = File::create_new("foo.txt")?; + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "file_create_new", issue = "none")] + pub fn create_new>(path: P) -> io::Result { + OpenOptions::new().read(true).write(true).create_new(true).open(path.as_ref()) + } + /// Returns a new OpenOptions object. /// /// This function returns a new OpenOptions object that you can use to @@ -703,8 +732,8 @@ impl Read for File { self.inner.read_vectored(bufs) } - fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> { - self.inner.read_buf(buf) + fn read_buf(&mut self, cursor: BorrowedCursor<'_>) -> io::Result<()> { + self.inner.read_buf(cursor) } #[inline] @@ -755,8 +784,8 @@ impl Read for &File { self.inner.read(buf) } - fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> { - self.inner.read_buf(buf) + fn read_buf(&mut self, cursor: BorrowedCursor<'_>) -> io::Result<()> { + self.inner.read_buf(cursor) } fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result { -- cgit v1.2.3