tempfile/file/
mod.rs

1use std::env;
2use std::error;
3use std::ffi::OsStr;
4use std::fmt;
5use std::fs::{self, File, OpenOptions};
6use std::io::{self, Read, Seek, SeekFrom, Write};
7use std::mem;
8use std::ops::Deref;
9#[cfg(unix)]
10use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
11#[cfg(target_os = "wasi")]
12use std::os::wasi::io::{AsFd, AsRawFd, BorrowedFd, RawFd};
13#[cfg(windows)]
14use std::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle, RawHandle};
15use std::path::{Path, PathBuf};
16
17use crate::error::IoResultExt;
18use crate::Builder;
19
20mod imp;
21
22/// Create a new temporary file.
23///
24/// The file will be created in the location returned by [`std::env::temp_dir()`].
25///
26/// # Security
27///
28/// This variant is secure/reliable in the presence of a pathological temporary file cleaner.
29///
30/// # Resource Leaking
31///
32/// The temporary file will be automatically removed by the OS when the last handle to it is closed.
33/// This doesn't rely on Rust destructors being run, so will (almost) never fail to clean up the temporary file.
34///
35/// # Errors
36///
37/// If the file can not be created, `Err` is returned.
38///
39/// # Examples
40///
41/// ```
42/// use tempfile::tempfile;
43/// use std::io::{self, Write};
44///
45/// # fn main() {
46/// #     if let Err(_) = run() {
47/// #         ::std::process::exit(1);
48/// #     }
49/// # }
50/// # fn run() -> Result<(), io::Error> {
51/// // Create a file inside of `std::env::temp_dir()`.
52/// let mut file = tempfile()?;
53///
54/// writeln!(file, "Brian was here. Briefly.")?;
55/// # Ok(())
56/// # }
57/// ```
58///
59/// [`std::env::temp_dir()`]: https://doc.rust-lang.org/std/env/fn.temp_dir.html
60pub fn tempfile() -> io::Result<File> {
61    tempfile_in(env::temp_dir())
62}
63
64/// Create a new temporary file in the specified directory.
65///
66/// # Security
67///
68/// This variant is secure/reliable in the presence of a pathological temporary file cleaner.
69/// If the temporary file isn't created in [`std::env::temp_dir()`] then temporary file cleaners aren't an issue.
70///
71/// # Resource Leaking
72///
73/// The temporary file will be automatically removed by the OS when the last handle to it is closed.
74/// This doesn't rely on Rust destructors being run, so will (almost) never fail to clean up the temporary file.
75///
76/// # Errors
77///
78/// If the file can not be created, `Err` is returned.
79///
80/// # Examples
81///
82/// ```
83/// use tempfile::tempfile_in;
84/// use std::io::{self, Write};
85///
86/// # fn main() {
87/// #     if let Err(_) = run() {
88/// #         ::std::process::exit(1);
89/// #     }
90/// # }
91/// # fn run() -> Result<(), io::Error> {
92/// // Create a file inside of the current working directory
93/// let mut file = tempfile_in("./")?;
94///
95/// writeln!(file, "Brian was here. Briefly.")?;
96/// # Ok(())
97/// # }
98/// ```
99///
100/// [`std::env::temp_dir()`]: https://doc.rust-lang.org/std/env/fn.temp_dir.html
101pub fn tempfile_in<P: AsRef<Path>>(dir: P) -> io::Result<File> {
102    imp::create(dir.as_ref())
103}
104
105/// Error returned when persisting a temporary file path fails.
106#[derive(Debug)]
107pub struct PathPersistError {
108    /// The underlying IO error.
109    pub error: io::Error,
110    /// The temporary file path that couldn't be persisted.
111    pub path: TempPath,
112}
113
114impl From<PathPersistError> for io::Error {
115    #[inline]
116    fn from(error: PathPersistError) -> io::Error {
117        error.error
118    }
119}
120
121impl From<PathPersistError> for TempPath {
122    #[inline]
123    fn from(error: PathPersistError) -> TempPath {
124        error.path
125    }
126}
127
128impl fmt::Display for PathPersistError {
129    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
130        write!(f, "failed to persist temporary file path: {}", self.error)
131    }
132}
133
134impl error::Error for PathPersistError {
135    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
136        Some(&self.error)
137    }
138}
139
140/// A path to a named temporary file without an open file handle.
141///
142/// This is useful when the temporary file needs to be used by a child process,
143/// for example.
144///
145/// When dropped, the temporary file is deleted.
146pub struct TempPath {
147    path: Box<Path>,
148}
149
150impl TempPath {
151    /// Close and remove the temporary file.
152    ///
153    /// Use this if you want to detect errors in deleting the file.
154    ///
155    /// # Errors
156    ///
157    /// If the file cannot be deleted, `Err` is returned.
158    ///
159    /// # Examples
160    ///
161    /// ```no_run
162    /// # use std::io;
163    /// use tempfile::NamedTempFile;
164    ///
165    /// # fn main() {
166    /// #     if let Err(_) = run() {
167    /// #         ::std::process::exit(1);
168    /// #     }
169    /// # }
170    /// # fn run() -> Result<(), io::Error> {
171    /// let file = NamedTempFile::new()?;
172    ///
173    /// // Close the file, but keep the path to it around.
174    /// let path = file.into_temp_path();
175    ///
176    /// // By closing the `TempPath` explicitly, we can check that it has
177    /// // been deleted successfully. If we don't close it explicitly, the
178    /// // file will still be deleted when `file` goes out of scope, but we
179    /// // won't know whether deleting the file succeeded.
180    /// path.close()?;
181    /// # Ok(())
182    /// # }
183    /// ```
184    pub fn close(mut self) -> io::Result<()> {
185        let result = fs::remove_file(&self.path).with_err_path(|| &*self.path);
186        self.path = PathBuf::new().into_boxed_path();
187        mem::forget(self);
188        result
189    }
190
191    /// Persist the temporary file at the target path.
192    ///
193    /// If a file exists at the target path, persist will atomically replace it.
194    /// If this method fails, it will return `self` in the resulting
195    /// [`PathPersistError`].
196    ///
197    /// Note: Temporary files cannot be persisted across filesystems. Also
198    /// neither the file contents nor the containing directory are
199    /// synchronized, so the update may not yet have reached the disk when
200    /// `persist` returns.
201    ///
202    /// # Security
203    ///
204    /// Only use this method if you're positive that a temporary file cleaner
205    /// won't have deleted your file. Otherwise, you might end up persisting an
206    /// attacker controlled file.
207    ///
208    /// # Errors
209    ///
210    /// If the file cannot be moved to the new location, `Err` is returned.
211    ///
212    /// # Examples
213    ///
214    /// ```no_run
215    /// # use std::io::{self, Write};
216    /// use tempfile::NamedTempFile;
217    ///
218    /// # fn main() {
219    /// #     if let Err(_) = run() {
220    /// #         ::std::process::exit(1);
221    /// #     }
222    /// # }
223    /// # fn run() -> Result<(), io::Error> {
224    /// let mut file = NamedTempFile::new()?;
225    /// writeln!(file, "Brian was here. Briefly.")?;
226    ///
227    /// let path = file.into_temp_path();
228    /// path.persist("./saved_file.txt")?;
229    /// # Ok(())
230    /// # }
231    /// ```
232    ///
233    /// [`PathPersistError`]: struct.PathPersistError.html
234    pub fn persist<P: AsRef<Path>>(mut self, new_path: P) -> Result<(), PathPersistError> {
235        match imp::persist(&self.path, new_path.as_ref(), true) {
236            Ok(_) => {
237                // Don't drop `self`. We don't want to try deleting the old
238                // temporary file path. (It'll fail, but the failure is never
239                // seen.)
240                self.path = PathBuf::new().into_boxed_path();
241                mem::forget(self);
242                Ok(())
243            }
244            Err(e) => Err(PathPersistError {
245                error: e,
246                path: self,
247            }),
248        }
249    }
250
251    /// Persist the temporary file at the target path if and only if no file exists there.
252    ///
253    /// If a file exists at the target path, fail. If this method fails, it will
254    /// return `self` in the resulting [`PathPersistError`].
255    ///
256    /// Note: Temporary files cannot be persisted across filesystems. Also Note:
257    /// This method is not atomic. It can leave the original link to the
258    /// temporary file behind.
259    ///
260    /// # Security
261    ///
262    /// Only use this method if you're positive that a temporary file cleaner
263    /// won't have deleted your file. Otherwise, you might end up persisting an
264    /// attacker controlled file.
265    ///
266    /// # Errors
267    ///
268    /// If the file cannot be moved to the new location or a file already exists
269    /// there, `Err` is returned.
270    ///
271    /// # Examples
272    ///
273    /// ```no_run
274    /// # use std::io::{self, Write};
275    /// use tempfile::NamedTempFile;
276    ///
277    /// # fn main() {
278    /// #     if let Err(_) = run() {
279    /// #         ::std::process::exit(1);
280    /// #     }
281    /// # }
282    /// # fn run() -> Result<(), io::Error> {
283    /// let mut file = NamedTempFile::new()?;
284    /// writeln!(file, "Brian was here. Briefly.")?;
285    ///
286    /// let path = file.into_temp_path();
287    /// path.persist_noclobber("./saved_file.txt")?;
288    /// # Ok(())
289    /// # }
290    /// ```
291    ///
292    /// [`PathPersistError`]: struct.PathPersistError.html
293    pub fn persist_noclobber<P: AsRef<Path>>(
294        mut self,
295        new_path: P,
296    ) -> Result<(), PathPersistError> {
297        match imp::persist(&self.path, new_path.as_ref(), false) {
298            Ok(_) => {
299                // Don't drop `self`. We don't want to try deleting the old
300                // temporary file path. (It'll fail, but the failure is never
301                // seen.)
302                self.path = PathBuf::new().into_boxed_path();
303                mem::forget(self);
304                Ok(())
305            }
306            Err(e) => Err(PathPersistError {
307                error: e,
308                path: self,
309            }),
310        }
311    }
312
313    /// Keep the temporary file from being deleted. This function will turn the
314    /// temporary file into a non-temporary file without moving it.
315    ///
316    ///
317    /// # Errors
318    ///
319    /// On some platforms (e.g., Windows), we need to mark the file as
320    /// non-temporary. This operation could fail.
321    ///
322    /// # Examples
323    ///
324    /// ```no_run
325    /// # use std::io::{self, Write};
326    /// use tempfile::NamedTempFile;
327    ///
328    /// # fn main() {
329    /// #     if let Err(_) = run() {
330    /// #         ::std::process::exit(1);
331    /// #     }
332    /// # }
333    /// # fn run() -> Result<(), io::Error> {
334    /// let mut file = NamedTempFile::new()?;
335    /// writeln!(file, "Brian was here. Briefly.")?;
336    ///
337    /// let path = file.into_temp_path();
338    /// let path = path.keep()?;
339    /// # Ok(())
340    /// # }
341    /// ```
342    ///
343    /// [`PathPersistError`]: struct.PathPersistError.html
344    pub fn keep(mut self) -> Result<PathBuf, PathPersistError> {
345        match imp::keep(&self.path) {
346            Ok(_) => {
347                // Don't drop `self`. We don't want to try deleting the old
348                // temporary file path. (It'll fail, but the failure is never
349                // seen.)
350                let path = mem::replace(&mut self.path, PathBuf::new().into_boxed_path());
351                mem::forget(self);
352                Ok(path.into())
353            }
354            Err(e) => Err(PathPersistError {
355                error: e,
356                path: self,
357            }),
358        }
359    }
360
361    /// Create a new TempPath from an existing path. This can be done even if no
362    /// file exists at the given path.
363    ///
364    /// This is mostly useful for interacting with libraries and external
365    /// components that provide files to be consumed or expect a path with no
366    /// existing file to be given.
367    pub fn from_path(path: impl Into<PathBuf>) -> Self {
368        Self {
369            path: path.into().into_boxed_path(),
370        }
371    }
372}
373
374impl fmt::Debug for TempPath {
375    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
376        self.path.fmt(f)
377    }
378}
379
380impl Drop for TempPath {
381    fn drop(&mut self) {
382        let _ = fs::remove_file(&self.path);
383    }
384}
385
386impl Deref for TempPath {
387    type Target = Path;
388
389    fn deref(&self) -> &Path {
390        &self.path
391    }
392}
393
394impl AsRef<Path> for TempPath {
395    fn as_ref(&self) -> &Path {
396        &self.path
397    }
398}
399
400impl AsRef<OsStr> for TempPath {
401    fn as_ref(&self) -> &OsStr {
402        self.path.as_os_str()
403    }
404}
405
406/// A named temporary file.
407///
408/// The default constructor, [`NamedTempFile::new()`], creates files in
409/// the location returned by [`std::env::temp_dir()`], but `NamedTempFile`
410/// can be configured to manage a temporary file in any location
411/// by constructing with [`NamedTempFile::new_in()`].
412///
413/// # Security
414///
415/// Most operating systems employ temporary file cleaners to delete old
416/// temporary files. Unfortunately these temporary file cleaners don't always
417/// reliably _detect_ whether the temporary file is still being used.
418///
419/// Specifically, the following sequence of events can happen:
420///
421/// 1. A user creates a temporary file with `NamedTempFile::new()`.
422/// 2. Time passes.
423/// 3. The temporary file cleaner deletes (unlinks) the temporary file from the
424///    filesystem.
425/// 4. Some other program creates a new file to replace this deleted temporary
426///    file.
427/// 5. The user tries to re-open the temporary file (in the same program or in a
428///    different program) by path. Unfortunately, they'll end up opening the
429///    file created by the other program, not the original file.
430///
431/// ## Operating System Specific Concerns
432///
433/// The behavior of temporary files and temporary file cleaners differ by
434/// operating system.
435///
436/// ### Windows
437///
438/// On Windows, open files _can't_ be deleted. This removes most of the concerns
439/// around temporary file cleaners.
440///
441/// Furthermore, temporary files are, by default, created in per-user temporary
442/// file directories so only an application running as the same user would be
443/// able to interfere (which they could do anyways). However, an application
444/// running as the same user can still _accidentally_ re-create deleted
445/// temporary files if the number of random bytes in the temporary file name is
446/// too small.
447///
448/// So, the only real concern on Windows is:
449///
450/// 1. Opening a named temporary file in a world-writable directory.
451/// 2. Using the `into_temp_path()` and/or `into_parts()` APIs to close the file
452///    handle without deleting the underlying file.
453/// 3. Continuing to use the file by path.
454///
455/// ### UNIX
456///
457/// Unlike on Windows, UNIX (and UNIX like) systems allow open files to be
458/// "unlinked" (deleted).
459///
460/// #### MacOS
461///
462/// Like on Windows, temporary files are created in per-user temporary file
463/// directories by default so calling `NamedTempFile::new()` should be
464/// relatively safe.
465///
466/// #### Linux
467///
468/// Unfortunately, most _Linux_ distributions don't create per-user temporary
469/// file directories. Worse, systemd's tmpfiles daemon (a common temporary file
470/// cleaner) will happily remove open temporary files if they haven't been
471/// modified within the last 10 days.
472///
473/// # Resource Leaking
474///
475/// If the program exits before the `NamedTempFile` destructor is
476/// run, the temporary file will not be deleted. This can happen
477/// if the process exits using [`std::process::exit()`], a segfault occurs,
478/// receiving an interrupt signal like `SIGINT` that is not handled, or by using
479/// a statically declared `NamedTempFile` instance (like with [`lazy_static`]).
480///
481/// Use the [`tempfile()`] function unless you need a named file path.
482///
483/// [`tempfile()`]: fn.tempfile.html
484/// [`NamedTempFile::new()`]: #method.new
485/// [`NamedTempFile::new_in()`]: #method.new_in
486/// [`std::env::temp_dir()`]: https://doc.rust-lang.org/std/env/fn.temp_dir.html
487/// [`std::process::exit()`]: http://doc.rust-lang.org/std/process/fn.exit.html
488/// [`lazy_static`]: https://github.com/rust-lang-nursery/lazy-static.rs/issues/62
489pub struct NamedTempFile<F = File> {
490    path: TempPath,
491    file: F,
492}
493
494impl<F> fmt::Debug for NamedTempFile<F> {
495    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
496        write!(f, "NamedTempFile({:?})", self.path)
497    }
498}
499
500impl<F> AsRef<Path> for NamedTempFile<F> {
501    #[inline]
502    fn as_ref(&self) -> &Path {
503        self.path()
504    }
505}
506
507/// Error returned when persisting a temporary file fails.
508pub struct PersistError<F = File> {
509    /// The underlying IO error.
510    pub error: io::Error,
511    /// The temporary file that couldn't be persisted.
512    pub file: NamedTempFile<F>,
513}
514
515impl<F> fmt::Debug for PersistError<F> {
516    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
517        write!(f, "PersistError({:?})", self.error)
518    }
519}
520
521impl<F> From<PersistError<F>> for io::Error {
522    #[inline]
523    fn from(error: PersistError<F>) -> io::Error {
524        error.error
525    }
526}
527
528impl<F> From<PersistError<F>> for NamedTempFile<F> {
529    #[inline]
530    fn from(error: PersistError<F>) -> NamedTempFile<F> {
531        error.file
532    }
533}
534
535impl<F> fmt::Display for PersistError<F> {
536    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
537        write!(f, "failed to persist temporary file: {}", self.error)
538    }
539}
540
541impl<F> error::Error for PersistError<F> {
542    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
543        Some(&self.error)
544    }
545}
546
547impl NamedTempFile<File> {
548    /// Create a new named temporary file.
549    ///
550    /// See [`Builder`] for more configuration.
551    ///
552    /// # Security
553    ///
554    /// This will create a temporary file in the default temporary file
555    /// directory (platform dependent). This has security implications on many
556    /// platforms so please read the security section of this type's
557    /// documentation.
558    ///
559    /// Reasons to use this method:
560    ///
561    ///   1. The file has a short lifetime and your temporary file cleaner is
562    ///      sane (doesn't delete recently accessed files).
563    ///
564    ///   2. You trust every user on your system (i.e. you are the only user).
565    ///
566    ///   3. You have disabled your system's temporary file cleaner or verified
567    ///      that your system doesn't have a temporary file cleaner.
568    ///
569    /// Reasons not to use this method:
570    ///
571    ///   1. You'll fix it later. No you won't.
572    ///
573    ///   2. You don't care about the security of the temporary file. If none of
574    ///      the "reasons to use this method" apply, referring to a temporary
575    ///      file by name may allow an attacker to create/overwrite your
576    ///      non-temporary files. There are exceptions but if you don't already
577    ///      know them, don't use this method.
578    ///
579    /// # Errors
580    ///
581    /// If the file can not be created, `Err` is returned.
582    ///
583    /// # Examples
584    ///
585    /// Create a named temporary file and write some data to it:
586    ///
587    /// ```no_run
588    /// # use std::io::{self, Write};
589    /// use tempfile::NamedTempFile;
590    ///
591    /// # fn main() {
592    /// #     if let Err(_) = run() {
593    /// #         ::std::process::exit(1);
594    /// #     }
595    /// # }
596    /// # fn run() -> Result<(), ::std::io::Error> {
597    /// let mut file = NamedTempFile::new()?;
598    ///
599    /// writeln!(file, "Brian was here. Briefly.")?;
600    /// # Ok(())
601    /// # }
602    /// ```
603    ///
604    /// [`Builder`]: struct.Builder.html
605    pub fn new() -> io::Result<NamedTempFile> {
606        Builder::new().tempfile()
607    }
608
609    /// Create a new named temporary file in the specified directory.
610    ///
611    /// This is equivalent to:
612    ///
613    /// ```ignore
614    /// Builder::new().tempfile_in(dir)
615    /// ```
616    ///
617    /// See [`NamedTempFile::new()`] for details.
618    ///
619    /// [`NamedTempFile::new()`]: #method.new
620    pub fn new_in<P: AsRef<Path>>(dir: P) -> io::Result<NamedTempFile> {
621        Builder::new().tempfile_in(dir)
622    }
623
624    /// Create a new named temporary file with the specified filename prefix.
625    ///
626    /// See [`NamedTempFile::new()`] for details.
627    ///
628    /// [`NamedTempFile::new()`]: #method.new
629    pub fn with_prefix<S: AsRef<OsStr>>(prefix: S) -> io::Result<NamedTempFile> {
630        Builder::new().prefix(&prefix).tempfile()
631    }
632    /// Create a new named temporary file with the specified filename prefix,
633    /// in the specified directory.
634    ///
635    /// This is equivalent to:
636    ///
637    /// ```ignore
638    /// Builder::new().prefix(&prefix).tempfile_in(directory)
639    /// ```
640    ///
641    /// See [`NamedTempFile::new()`] for details.
642    ///
643    /// [`NamedTempFile::new()`]: #method.new
644    pub fn with_prefix_in<S: AsRef<OsStr>, P: AsRef<Path>>(
645        prefix: S,
646        dir: P,
647    ) -> io::Result<NamedTempFile> {
648        Builder::new().prefix(&prefix).tempfile_in(dir)
649    }
650}
651
652impl<F> NamedTempFile<F> {
653    /// Get the temporary file's path.
654    ///
655    /// # Security
656    ///
657    /// Referring to a temporary file's path may not be secure in all cases.
658    /// Please read the security section on the top level documentation of this
659    /// type for details.
660    ///
661    /// # Examples
662    ///
663    /// ```no_run
664    /// # use std::io::{self, Write};
665    /// use tempfile::NamedTempFile;
666    ///
667    /// # fn main() {
668    /// #     if let Err(_) = run() {
669    /// #         ::std::process::exit(1);
670    /// #     }
671    /// # }
672    /// # fn run() -> Result<(), ::std::io::Error> {
673    /// let file = NamedTempFile::new()?;
674    ///
675    /// println!("{:?}", file.path());
676    /// # Ok(())
677    /// # }
678    /// ```
679    #[inline]
680    pub fn path(&self) -> &Path {
681        &self.path
682    }
683
684    /// Close and remove the temporary file.
685    ///
686    /// Use this if you want to detect errors in deleting the file.
687    ///
688    /// # Errors
689    ///
690    /// If the file cannot be deleted, `Err` is returned.
691    ///
692    /// # Examples
693    ///
694    /// ```no_run
695    /// # use std::io;
696    /// use tempfile::NamedTempFile;
697    ///
698    /// # fn main() {
699    /// #     if let Err(_) = run() {
700    /// #         ::std::process::exit(1);
701    /// #     }
702    /// # }
703    /// # fn run() -> Result<(), io::Error> {
704    /// let file = NamedTempFile::new()?;
705    ///
706    /// // By closing the `NamedTempFile` explicitly, we can check that it has
707    /// // been deleted successfully. If we don't close it explicitly,
708    /// // the file will still be deleted when `file` goes out
709    /// // of scope, but we won't know whether deleting the file
710    /// // succeeded.
711    /// file.close()?;
712    /// # Ok(())
713    /// # }
714    /// ```
715    pub fn close(self) -> io::Result<()> {
716        let NamedTempFile { path, .. } = self;
717        path.close()
718    }
719
720    /// Persist the temporary file at the target path.
721    ///
722    /// If a file exists at the target path, persist will atomically replace it.
723    /// If this method fails, it will return `self` in the resulting
724    /// [`PersistError`].
725    ///
726    /// Note: Temporary files cannot be persisted across filesystems. Also
727    /// neither the file contents nor the containing directory are
728    /// synchronized, so the update may not yet have reached the disk when
729    /// `persist` returns.
730    ///
731    /// # Security
732    ///
733    /// This method persists the temporary file using its path and may not be
734    /// secure in all cases. Please read the security section on the top
735    /// level documentation of this type for details.
736    ///
737    /// # Errors
738    ///
739    /// If the file cannot be moved to the new location, `Err` is returned.
740    ///
741    /// # Examples
742    ///
743    /// ```no_run
744    /// # use std::io::{self, Write};
745    /// use tempfile::NamedTempFile;
746    ///
747    /// # fn main() {
748    /// #     if let Err(_) = run() {
749    /// #         ::std::process::exit(1);
750    /// #     }
751    /// # }
752    /// # fn run() -> Result<(), io::Error> {
753    /// let file = NamedTempFile::new()?;
754    ///
755    /// let mut persisted_file = file.persist("./saved_file.txt")?;
756    /// writeln!(persisted_file, "Brian was here. Briefly.")?;
757    /// # Ok(())
758    /// # }
759    /// ```
760    ///
761    /// [`PersistError`]: struct.PersistError.html
762    pub fn persist<P: AsRef<Path>>(self, new_path: P) -> Result<F, PersistError<F>> {
763        let NamedTempFile { path, file } = self;
764        match path.persist(new_path) {
765            Ok(_) => Ok(file),
766            Err(err) => {
767                let PathPersistError { error, path } = err;
768                Err(PersistError {
769                    file: NamedTempFile { path, file },
770                    error,
771                })
772            }
773        }
774    }
775
776    /// Persist the temporary file at the target path if and only if no file exists there.
777    ///
778    /// If a file exists at the target path, fail. If this method fails, it will
779    /// return `self` in the resulting PersistError.
780    ///
781    /// Note: Temporary files cannot be persisted across filesystems. Also Note:
782    /// This method is not atomic. It can leave the original link to the
783    /// temporary file behind.
784    ///
785    /// # Security
786    ///
787    /// This method persists the temporary file using its path and may not be
788    /// secure in all cases. Please read the security section on the top
789    /// level documentation of this type for details.
790    ///
791    /// # Errors
792    ///
793    /// If the file cannot be moved to the new location or a file already exists there,
794    /// `Err` is returned.
795    ///
796    /// # Examples
797    ///
798    /// ```no_run
799    /// # use std::io::{self, Write};
800    /// use tempfile::NamedTempFile;
801    ///
802    /// # fn main() {
803    /// #     if let Err(_) = run() {
804    /// #         ::std::process::exit(1);
805    /// #     }
806    /// # }
807    /// # fn run() -> Result<(), io::Error> {
808    /// let file = NamedTempFile::new()?;
809    ///
810    /// let mut persisted_file = file.persist_noclobber("./saved_file.txt")?;
811    /// writeln!(persisted_file, "Brian was here. Briefly.")?;
812    /// # Ok(())
813    /// # }
814    /// ```
815    pub fn persist_noclobber<P: AsRef<Path>>(self, new_path: P) -> Result<F, PersistError<F>> {
816        let NamedTempFile { path, file } = self;
817        match path.persist_noclobber(new_path) {
818            Ok(_) => Ok(file),
819            Err(err) => {
820                let PathPersistError { error, path } = err;
821                Err(PersistError {
822                    file: NamedTempFile { path, file },
823                    error,
824                })
825            }
826        }
827    }
828
829    /// Keep the temporary file from being deleted. This function will turn the
830    /// temporary file into a non-temporary file without moving it.
831    ///
832    ///
833    /// # Errors
834    ///
835    /// On some platforms (e.g., Windows), we need to mark the file as
836    /// non-temporary. This operation could fail.
837    ///
838    /// # Examples
839    ///
840    /// ```no_run
841    /// # use std::io::{self, Write};
842    /// use tempfile::NamedTempFile;
843    ///
844    /// # fn main() {
845    /// #     if let Err(_) = run() {
846    /// #         ::std::process::exit(1);
847    /// #     }
848    /// # }
849    /// # fn run() -> Result<(), io::Error> {
850    /// let mut file = NamedTempFile::new()?;
851    /// writeln!(file, "Brian was here. Briefly.")?;
852    ///
853    /// let (file, path) = file.keep()?;
854    /// # Ok(())
855    /// # }
856    /// ```
857    ///
858    /// [`PathPersistError`]: struct.PathPersistError.html
859    pub fn keep(self) -> Result<(F, PathBuf), PersistError<F>> {
860        let (file, path) = (self.file, self.path);
861        match path.keep() {
862            Ok(path) => Ok((file, path)),
863            Err(PathPersistError { error, path }) => Err(PersistError {
864                file: NamedTempFile { path, file },
865                error,
866            }),
867        }
868    }
869
870    /// Get a reference to the underlying file.
871    pub fn as_file(&self) -> &F {
872        &self.file
873    }
874
875    /// Get a mutable reference to the underlying file.
876    pub fn as_file_mut(&mut self) -> &mut F {
877        &mut self.file
878    }
879
880    /// Convert the temporary file into a `std::fs::File`.
881    ///
882    /// The inner file will be deleted.
883    pub fn into_file(self) -> F {
884        self.file
885    }
886
887    /// Closes the file, leaving only the temporary file path.
888    ///
889    /// This is useful when another process must be able to open the temporary
890    /// file.
891    pub fn into_temp_path(self) -> TempPath {
892        self.path
893    }
894
895    /// Converts the named temporary file into its constituent parts.
896    ///
897    /// Note: When the path is dropped, the file is deleted but the file handle
898    /// is still usable.
899    pub fn into_parts(self) -> (F, TempPath) {
900        (self.file, self.path)
901    }
902
903    /// Creates a `NamedTempFile` from its constituent parts.
904    ///
905    /// This can be used with [`NamedTempFile::into_parts`] to reconstruct the
906    /// `NamedTempFile`.
907    pub fn from_parts(file: F, path: TempPath) -> Self {
908        Self { file, path }
909    }
910}
911
912impl NamedTempFile<File> {
913    /// Securely reopen the temporary file.
914    ///
915    /// This function is useful when you need multiple independent handles to
916    /// the same file. It's perfectly fine to drop the original `NamedTempFile`
917    /// while holding on to `File`s returned by this function; the `File`s will
918    /// remain usable. However, they may not be nameable.
919    ///
920    /// # Errors
921    ///
922    /// If the file cannot be reopened, `Err` is returned.
923    ///
924    /// # Security
925    ///
926    /// Unlike `File::open(my_temp_file.path())`, `NamedTempFile::reopen()`
927    /// guarantees that the re-opened file is the _same_ file, even in the
928    /// presence of pathological temporary file cleaners.
929    ///
930    /// # Examples
931    ///
932    /// ```no_run
933    /// # use std::io;
934    /// use tempfile::NamedTempFile;
935    ///
936    /// # fn main() {
937    /// #     if let Err(_) = run() {
938    /// #         ::std::process::exit(1);
939    /// #     }
940    /// # }
941    /// # fn run() -> Result<(), io::Error> {
942    /// let file = NamedTempFile::new()?;
943    ///
944    /// let another_handle = file.reopen()?;
945    /// # Ok(())
946    /// # }
947    /// ```
948    pub fn reopen(&self) -> io::Result<File> {
949        imp::reopen(self.as_file(), NamedTempFile::path(self))
950            .with_err_path(|| NamedTempFile::path(self))
951    }
952}
953
954impl<F: Read> Read for NamedTempFile<F> {
955    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
956        self.as_file_mut().read(buf).with_err_path(|| self.path())
957    }
958
959    fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
960        self.as_file_mut()
961            .read_vectored(bufs)
962            .with_err_path(|| self.path())
963    }
964
965    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
966        self.as_file_mut()
967            .read_to_end(buf)
968            .with_err_path(|| self.path())
969    }
970
971    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
972        self.as_file_mut()
973            .read_to_string(buf)
974            .with_err_path(|| self.path())
975    }
976
977    fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
978        self.as_file_mut()
979            .read_exact(buf)
980            .with_err_path(|| self.path())
981    }
982}
983
984impl Read for &NamedTempFile<File> {
985    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
986        self.as_file().read(buf).with_err_path(|| self.path())
987    }
988
989    fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
990        self.as_file()
991            .read_vectored(bufs)
992            .with_err_path(|| self.path())
993    }
994
995    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
996        self.as_file()
997            .read_to_end(buf)
998            .with_err_path(|| self.path())
999    }
1000
1001    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
1002        self.as_file()
1003            .read_to_string(buf)
1004            .with_err_path(|| self.path())
1005    }
1006
1007    fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
1008        self.as_file().read_exact(buf).with_err_path(|| self.path())
1009    }
1010}
1011
1012impl<F: Write> Write for NamedTempFile<F> {
1013    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
1014        self.as_file_mut().write(buf).with_err_path(|| self.path())
1015    }
1016    #[inline]
1017    fn flush(&mut self) -> io::Result<()> {
1018        self.as_file_mut().flush().with_err_path(|| self.path())
1019    }
1020
1021    fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result<usize> {
1022        self.as_file_mut()
1023            .write_vectored(bufs)
1024            .with_err_path(|| self.path())
1025    }
1026
1027    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
1028        self.as_file_mut()
1029            .write_all(buf)
1030            .with_err_path(|| self.path())
1031    }
1032
1033    fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
1034        self.as_file_mut()
1035            .write_fmt(fmt)
1036            .with_err_path(|| self.path())
1037    }
1038}
1039
1040impl Write for &NamedTempFile<File> {
1041    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
1042        self.as_file().write(buf).with_err_path(|| self.path())
1043    }
1044    #[inline]
1045    fn flush(&mut self) -> io::Result<()> {
1046        self.as_file().flush().with_err_path(|| self.path())
1047    }
1048
1049    fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result<usize> {
1050        self.as_file()
1051            .write_vectored(bufs)
1052            .with_err_path(|| self.path())
1053    }
1054
1055    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
1056        self.as_file().write_all(buf).with_err_path(|| self.path())
1057    }
1058
1059    fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
1060        self.as_file().write_fmt(fmt).with_err_path(|| self.path())
1061    }
1062}
1063
1064impl<F: Seek> Seek for NamedTempFile<F> {
1065    fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
1066        self.as_file_mut().seek(pos).with_err_path(|| self.path())
1067    }
1068}
1069
1070impl Seek for &NamedTempFile<File> {
1071    fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
1072        self.as_file().seek(pos).with_err_path(|| self.path())
1073    }
1074}
1075
1076#[cfg(any(unix, target_os = "wasi"))]
1077impl<F: AsFd> AsFd for NamedTempFile<F> {
1078    fn as_fd(&self) -> BorrowedFd<'_> {
1079        self.as_file().as_fd()
1080    }
1081}
1082
1083#[cfg(any(unix, target_os = "wasi"))]
1084impl<F: AsRawFd> AsRawFd for NamedTempFile<F> {
1085    #[inline]
1086    fn as_raw_fd(&self) -> RawFd {
1087        self.as_file().as_raw_fd()
1088    }
1089}
1090
1091#[cfg(windows)]
1092impl<F: AsHandle> AsHandle for NamedTempFile<F> {
1093    #[inline]
1094    fn as_handle(&self) -> BorrowedHandle<'_> {
1095        self.as_file().as_handle()
1096    }
1097}
1098
1099#[cfg(windows)]
1100impl<F: AsRawHandle> AsRawHandle for NamedTempFile<F> {
1101    #[inline]
1102    fn as_raw_handle(&self) -> RawHandle {
1103        self.as_file().as_raw_handle()
1104    }
1105}
1106
1107pub(crate) fn create_named(
1108    mut path: PathBuf,
1109    open_options: &mut OpenOptions,
1110) -> io::Result<NamedTempFile> {
1111    // Make the path absolute. Otherwise, changing directories could cause us to
1112    // delete the wrong file.
1113    if !path.is_absolute() {
1114        path = env::current_dir()?.join(path)
1115    }
1116    imp::create_named(&path, open_options)
1117        .with_err_path(|| path.clone())
1118        .map(|file| NamedTempFile {
1119            path: TempPath {
1120                path: path.into_boxed_path(),
1121            },
1122            file,
1123        })
1124}