Struct otter_api_tests::NamedTempFile [−][src]
pub struct NamedTempFile { /* fields omitted */ }
Expand description
A named temporary file.
The default constructor, NamedTempFile::new()
, creates files in
the location returned by std::env::temp_dir()
, but NamedTempFile
can be configured to manage a temporary file in any location
by constructing with NamedTempFile::new_in()
.
Security
Most operating systems employ temporary file cleaners to delete old temporary files. Unfortunately these temporary file cleaners don’t always reliably detect whether the temporary file is still being used.
Specifically, the following sequence of events can happen:
- A user creates a temporary file with
NamedTempFile::new()
. - Time passes.
- The temporary file cleaner deletes (unlinks) the temporary file from the filesystem.
- Some other program creates a new file to replace this deleted temporary file.
- The user tries to re-open the temporary file (in the same program or in a different program) by path. Unfortunately, they’ll end up opening the file created by the other program, not the original file.
Operating System Specific Concerns
The behavior of temporary files and temporary file cleaners differ by operating system.
Windows
On Windows, open files can’t be deleted. This removes most of the concerns around temporary file cleaners.
Furthermore, temporary files are, by default, created in per-user temporary file directories so only an application running as the same user would be able to interfere (which they could do anyways). However, an application running as the same user can still accidentally re-create deleted temporary files if the number of random bytes in the temporary file name is too small.
So, the only real concern on Windows is:
- Opening a named temporary file in a world-writable directory.
- Using the
into_temp_path()
and/orinto_parts()
APIs to close the file handle without deleting the underlying file. - Continuing to use the file by path.
UNIX
Unlike on Windows, UNIX (and UNIX like) systems allow open files to be “unlinked” (deleted).
MacOS
Like on Windows, temporary files are created in per-user temporary file
directories by default so calling NamedTempFile::new()
should be
relatively safe.
Linux
Unfortunately, most Linux distributions don’t create per-user temporary file directories. Worse, systemd’s tmpfiles daemon (a common temporary file cleaner) will happily remove open temporary files if they haven’t been modified within the last 10 days.
Resource Leaking
If the program exits before the NamedTempFile
destructor is
run, such as via std::process::exit()
, by segfaulting, or by
receiving a signal like SIGINT
, then the temporary file
will not be deleted.
Use the tempfile()
function unless you absolutely need a named file.
Implementations
Create a new named temporary file.
See Builder
for more configuration.
Security
This will create a temporary file in the default temporary file directory (platform dependent). This has security implications on many platforms so please read the security section of this type’s documentation.
Reasons to use this method:
-
The file has a short lifetime and your temporary file cleaner is sane (doesn’t delete recently accessed files).
-
You trust every user on your system (i.e. you are the only user).
-
You have disabled your system’s temporary file cleaner or verified that your system doesn’t have a temporary file cleaner.
Reasons not to use this method:
-
You’ll fix it later. No you won’t.
-
You don’t care about the security of the temporary file. If none of the “reasons to use this method” apply, referring to a temporary file by name may allow an attacker to create/overwrite your non-temporary files. There are exceptions but if you don’t already know them, don’t use this method.
Errors
If the file can not be created, Err
is returned.
Examples
Create a named temporary file and write some data to it:
use tempfile::NamedTempFile; let mut file = NamedTempFile::new()?; writeln!(file, "Brian was here. Briefly.")?;
Create a new named temporary file in the specified directory.
See NamedTempFile::new()
for details.
Get the temporary file’s path.
Security
Referring to a temporary file’s path may not be secure in all cases. Please read the security section on the top level documentation of this type for details.
Examples
use tempfile::NamedTempFile; let file = NamedTempFile::new()?; println!("{:?}", file.path());
Close and remove the temporary file.
Use this if you want to detect errors in deleting the file.
Errors
If the file cannot be deleted, Err
is returned.
Examples
use tempfile::NamedTempFile; let file = NamedTempFile::new()?; // By closing the `NamedTempFile` explicitly, we can check that it has // been deleted successfully. If we don't close it explicitly, // the file will still be deleted when `file` goes out // of scope, but we won't know whether deleting the file // succeeded. file.close()?;
Persist the temporary file at the target path.
If a file exists at the target path, persist will atomically replace it.
If this method fails, it will return self
in the resulting
PersistError
.
Note: Temporary files cannot be persisted across filesystems. Also
neither the file contents nor the containing directory are
synchronized, so the update may not yet have reached the disk when
persist
returns.
Security
This method persists the temporary file using its path and may not be secure in the in all cases. Please read the security section on the top level documentation of this type for details.
Errors
If the file cannot be moved to the new location, Err
is returned.
Examples
use tempfile::NamedTempFile; let file = NamedTempFile::new()?; let mut persisted_file = file.persist("./saved_file.txt")?; writeln!(persisted_file, "Brian was here. Briefly.")?;
pub fn persist_noclobber<P>(self, new_path: P) -> Result<File, PersistError> where
P: AsRef<Path>,
[src]
pub fn persist_noclobber<P>(self, new_path: P) -> Result<File, PersistError> where
P: AsRef<Path>,
[src]Persist the temporary file at the target path if and only if no file exists there.
If a file exists at the target path, fail. If this method fails, it will
return self
in the resulting PersistError.
Note: Temporary files cannot be persisted across filesystems. Also Note: This method is not atomic. It can leave the original link to the temporary file behind.
Security
This method persists the temporary file using its path and may not be secure in the in all cases. Please read the security section on the top level documentation of this type for details.
Errors
If the file cannot be moved to the new location or a file already exists there,
Err
is returned.
Examples
use tempfile::NamedTempFile; let file = NamedTempFile::new()?; let mut persisted_file = file.persist_noclobber("./saved_file.txt")?; writeln!(persisted_file, "Brian was here. Briefly.")?;
Keep the temporary file from being deleted. This function will turn the temporary file into a non-temporary file without moving it.
Errors
On some platforms (e.g., Windows), we need to mark the file as non-temporary. This operation could fail.
Examples
use tempfile::NamedTempFile; let mut file = NamedTempFile::new()?; writeln!(file, "Brian was here. Briefly.")?; let (file, path) = file.keep()?;
Securely reopen the temporary file.
This function is useful when you need multiple independent handles to
the same file. It’s perfectly fine to drop the original NamedTempFile
while holding on to File
s returned by this function; the File
s will
remain usable. However, they may not be nameable.
Errors
If the file cannot be reopened, Err
is returned.
Security
Unlike File::open(my_temp_file.path())
, NamedTempFile::reopen()
guarantees that the re-opened file is the same file, even in the
presence of pathological temporary file cleaners.
Examples
use tempfile::NamedTempFile; let file = NamedTempFile::new()?; let another_handle = file.reopen()?;
Get a reference to the underlying file.
Get a mutable reference to the underlying file.
Convert the temporary file into a std::fs::File
.
The inner file will be deleted.
Closes the file, leaving only the temporary file path.
This is useful when another process must be able to open the temporary file.
Trait Implementations
pub fn from(error: PersistError) -> NamedTempFileⓘNotable traits for NamedTempFile
impl Write for NamedTempFileimpl<'a> Write for &'a NamedTempFileimpl Read for NamedTempFileimpl<'a> Read for &'a NamedTempFile
[src]
pub fn from(error: PersistError) -> NamedTempFileⓘNotable traits for NamedTempFile
impl Write for NamedTempFileimpl<'a> Write for &'a NamedTempFileimpl Read for NamedTempFileimpl<'a> Read for &'a NamedTempFile
[src]Performs the conversion.
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
Like read
, except that it reads into a slice of buffers. Read more
can_vector
)Determines if this Read
er has an efficient read_vectored
implementation. Read more
read_initializer
)Determines if this Read
er can work with buffers of uninitialized
memory. Read more
Read all bytes until EOF in this source, placing them into buf
. Read more
Read all bytes until EOF in this source, appending them to buf
. Read more
Read the exact number of bytes required to fill buf
. Read more
Creates a “by reference” adaptor for this instance of Read
. Read more
Creates an adaptor which will chain this stream with another. Read more
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
Like read
, except that it reads into a slice of buffers. Read more
can_vector
)Determines if this Read
er has an efficient read_vectored
implementation. Read more
read_initializer
)Determines if this Read
er can work with buffers of uninitialized
memory. Read more
Read all bytes until EOF in this source, placing them into buf
. Read more
Read all bytes until EOF in this source, appending them to buf
. Read more
Read the exact number of bytes required to fill buf
. Read more
Creates a “by reference” adaptor for this instance of Read
. Read more
Creates an adaptor which will chain this stream with another. Read more
Write a buffer into this writer, returning how many bytes were written. Read more
Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
can_vector
)Determines if this Write
r has an efficient write_vectored
implementation. Read more
Attempts to write an entire buffer into this writer. Read more
write_all_vectored
)Attempts to write multiple buffers into this writer. Read more
Writes a formatted string into this writer, returning any error encountered. Read more
Write a buffer into this writer, returning how many bytes were written. Read more
Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
can_vector
)Determines if this Write
r has an efficient write_vectored
implementation. Read more
Attempts to write an entire buffer into this writer. Read more
write_all_vectored
)Attempts to write multiple buffers into this writer. Read more
Writes a formatted string into this writer, returning any error encountered. Read more
Auto Trait Implementations
impl RefUnwindSafe for NamedTempFile
impl Send for NamedTempFile
impl Sync for NamedTempFile
impl Unpin for NamedTempFile
impl UnwindSafe for NamedTempFile
Blanket Implementations
Mutably borrows from an owned value. Read more
pub fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>ⓘNotable traits for Box<R, Global>
impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<I, A> Iterator for Box<I, A> where
A: Allocator,
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<F, A> Future for Box<F, A> where
A: Allocator + 'static,
F: Future + Unpin + ?Sized, type Output = <F as Future>::Output;
pub fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>ⓘNotable traits for Box<R, Global>
impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<I, A> Iterator for Box<I, A> where
A: Allocator,
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<F, A> Future for Box<F, A> where
A: Allocator + 'static,
F: Future + Unpin + ?Sized, type Output = <F as Future>::Output;
Convert Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
. Read more
pub fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
pub fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Convert Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read more
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read more
pub fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
pub fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert &mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s. Read more
impl<A> DynCastExt for A
impl<A> DynCastExt for A
pub fn dyn_cast<T>(
self
) -> Result<<A as DynCastExtHelper<T>>::Target, <A as DynCastExtHelper<T>>::Source> where
T: ?Sized,
A: DynCastExtHelper<T>,
pub fn dyn_cast<T>(
self
) -> Result<<A as DynCastExtHelper<T>>::Target, <A as DynCastExtHelper<T>>::Source> where
T: ?Sized,
A: DynCastExtHelper<T>,
Use this to cast from one trait object type to another. Read more
pub fn dyn_upcast<T>(self) -> <A as DynCastExtAdvHelper<T, T>>::Target where
T: ?Sized,
A: DynCastExtAdvHelper<T, T, Source = <A as DynCastExtAdvHelper<T, T>>::Target>,
pub fn dyn_upcast<T>(self) -> <A as DynCastExtAdvHelper<T, T>>::Target where
T: ?Sized,
A: DynCastExtAdvHelper<T, T, Source = <A as DynCastExtAdvHelper<T, T>>::Target>,
Use this to upcast a trait to one of its supertraits. Read more
pub fn dyn_cast_adv<F, T>(
self
) -> Result<<A as DynCastExtAdvHelper<F, T>>::Target, <A as DynCastExtAdvHelper<F, T>>::Source> where
T: ?Sized,
A: DynCastExtAdvHelper<F, T>,
F: ?Sized,
pub fn dyn_cast_adv<F, T>(
self
) -> Result<<A as DynCastExtAdvHelper<F, T>>::Target, <A as DynCastExtAdvHelper<F, T>>::Source> where
T: ?Sized,
A: DynCastExtAdvHelper<F, T>,
F: ?Sized,
pub fn dyn_cast_with_config<C>(
self
) -> Result<<A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Target, <A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Source> where
C: DynCastConfig,
A: DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>,
pub fn dyn_cast_with_config<C>(
self
) -> Result<<A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Target, <A as DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>>::Source> where
C: DynCastConfig,
A: DynCastExtAdvHelper<<C as DynCastConfig>::Source, <C as DynCastConfig>::Target>,
Use this to cast from one trait object type to another. With this method the type parameter is a config type that uniquely specifies which cast should be preformed. Read more
fn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>
impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
[src]
fn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>
impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
[src]Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
fn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>
impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
[src]
fn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>
impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
[src]impl<R> ReadBytesExt for R where
R: Read + ?Sized,
impl<R> ReadBytesExt for R where
R: Read + ?Sized,
Reads an unsigned 8 bit integer from the underlying reader. Read more
Reads a signed 8 bit integer from the underlying reader. Read more
Reads an unsigned 16 bit integer from the underlying reader. Read more
Reads a signed 16 bit integer from the underlying reader. Read more
Reads an unsigned 24 bit integer from the underlying reader. Read more
Reads a signed 24 bit integer from the underlying reader. Read more
Reads an unsigned 32 bit integer from the underlying reader. Read more
Reads a signed 32 bit integer from the underlying reader. Read more
Reads an unsigned 48 bit integer from the underlying reader. Read more
Reads a signed 48 bit integer from the underlying reader. Read more
Reads an unsigned 64 bit integer from the underlying reader. Read more
Reads a signed 64 bit integer from the underlying reader. Read more
Reads an unsigned 128 bit integer from the underlying reader. Read more
Reads a signed 128 bit integer from the underlying reader. Read more
Reads an unsigned n-bytes integer from the underlying reader. Read more
Reads a signed n-bytes integer from the underlying reader. Read more
fn read_uint128<T>(&mut self, nbytes: usize) -> Result<u128, Error> where
T: ByteOrder,
fn read_uint128<T>(&mut self, nbytes: usize) -> Result<u128, Error> where
T: ByteOrder,
Reads an unsigned n-bytes integer from the underlying reader.
fn read_int128<T>(&mut self, nbytes: usize) -> Result<i128, Error> where
T: ByteOrder,
fn read_int128<T>(&mut self, nbytes: usize) -> Result<i128, Error> where
T: ByteOrder,
Reads a signed n-bytes integer from the underlying reader.
Reads a IEEE754 single-precision (4 bytes) floating point number from the underlying reader. Read more
Reads a IEEE754 double-precision (8 bytes) floating point number from the underlying reader. Read more
Reads a sequence of unsigned 16 bit integers from the underlying reader. Read more
Reads a sequence of unsigned 32 bit integers from the underlying reader. Read more
Reads a sequence of unsigned 64 bit integers from the underlying reader. Read more
Reads a sequence of unsigned 128 bit integers from the underlying reader. Read more
Reads a sequence of signed 8 bit integers from the underlying reader. Read more
Reads a sequence of signed 16 bit integers from the underlying reader. Read more
Reads a sequence of signed 32 bit integers from the underlying reader. Read more
Reads a sequence of signed 64 bit integers from the underlying reader. Read more
Reads a sequence of signed 128 bit integers from the underlying reader. Read more
Reads a sequence of IEEE754 single-precision (4 bytes) floating point numbers from the underlying reader. Read more
Reads a sequence of IEEE754 double-precision (8 bytes) floating point numbers from the underlying reader. Read more
pub fn read_rmp<T>(&mut self) -> Result<T, MgmtChannelReadError> where
T: DeserializeOwned,
R: Read,
[src]pub fn vzip(self) -> V
impl<W> WriteBytesExt for W where
W: Write + ?Sized,
impl<W> WriteBytesExt for W where
W: Write + ?Sized,
Writes an unsigned 8 bit integer to the underlying writer. Read more
Writes a signed 8 bit integer to the underlying writer. Read more
Writes an unsigned 16 bit integer to the underlying writer. Read more
Writes a signed 16 bit integer to the underlying writer. Read more
Writes an unsigned 24 bit integer to the underlying writer. Read more
Writes a signed 24 bit integer to the underlying writer. Read more
Writes an unsigned 32 bit integer to the underlying writer. Read more
Writes a signed 32 bit integer to the underlying writer. Read more
Writes an unsigned 48 bit integer to the underlying writer. Read more
Writes a signed 48 bit integer to the underlying writer. Read more
Writes an unsigned 64 bit integer to the underlying writer. Read more
Writes a signed 64 bit integer to the underlying writer. Read more
fn write_u128<T>(&mut self, n: u128) -> Result<(), Error> where
T: ByteOrder,
fn write_u128<T>(&mut self, n: u128) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned 128 bit integer to the underlying writer.
fn write_i128<T>(&mut self, n: i128) -> Result<(), Error> where
T: ByteOrder,
fn write_i128<T>(&mut self, n: i128) -> Result<(), Error> where
T: ByteOrder,
Writes a signed 128 bit integer to the underlying writer.
Writes an unsigned n-bytes integer to the underlying writer. Read more
Writes a signed n-bytes integer to the underlying writer. Read more
Writes an unsigned n-bytes integer to the underlying writer. Read more
Writes a signed n-bytes integer to the underlying writer. Read more
Writes a IEEE754 single-precision (4 bytes) floating point number to the underlying writer. Read more