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