pub struct Stderr { /* private fields */ }
Expand description
A handle to the standard error stream of a process.
For more information, see the io::stderr
method.
Note: Windows Portability Considerations
When operating in a console, the Windows implementation of this stream does not support non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return an error.
In a process with a detached console, such as one using
#![windows_subsystem = "windows"]
, or in a child process spawned from such a process,
the contained handle will be null. In such cases, the standard library’s Read
and
Write
will do nothing and silently succeed. All other I/O operations, via the
standard library or via raw Windows API calls, will fail.
Implementations
sourceimpl Stderr
impl Stderr
sourcepub fn lock(&self) -> StderrLock<'static>ⓘNotable traits for StderrLock<'_>impl<'_> Write for StderrLock<'_>
pub fn lock(&self) -> StderrLock<'static>ⓘNotable traits for StderrLock<'_>impl<'_> Write for StderrLock<'_>
Locks this handle to the standard error stream, returning a writable guard.
The lock is released when the returned lock goes out of scope. The
returned guard also implements the Write
trait for writing data.
Examples
use std::io::{self, Write};
fn foo() -> io::Result<()> {
let stderr = io::stderr();
let mut handle = stderr.lock();
handle.write_all(b"hello world")?;
Ok(())
}
Trait Implementations
1.63.0 · sourceimpl AsFd for Stderr
impl AsFd for Stderr
sourcefn as_fd(&self) -> BorrowedFd<'_>
fn as_fd(&self) -> BorrowedFd<'_>
Borrows the file descriptor. Read more
sourceimpl Write for Stderr
impl Write for Stderr
sourcefn write(&mut self, buf: &[u8]) -> Result<usize, Error>
fn write(&mut self, buf: &[u8]) -> Result<usize, Error>
Write a buffer into this writer, returning how many bytes were written. Read more
sourcefn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
can_vector
)Determines if this Write
r has an efficient write_vectored
implementation. Read more
sourcefn flush(&mut self) -> Result<(), Error>
fn flush(&mut self) -> Result<(), Error>
Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
sourcefn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
Attempts to write an entire buffer into this writer. Read more
sourcefn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
write_all_vectored
)Attempts to write multiple buffers into this writer. Read more
1.48.0 · sourceimpl<'_> Write for &Stderr
impl<'_> Write for &Stderr
sourcefn write(&mut self, buf: &[u8]) -> Result<usize, Error>
fn write(&mut self, buf: &[u8]) -> Result<usize, Error>
Write a buffer into this writer, returning how many bytes were written. Read more
sourcefn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
can_vector
)Determines if this Write
r has an efficient write_vectored
implementation. Read more
sourcefn flush(&mut self) -> Result<(), Error>
fn flush(&mut self) -> Result<(), Error>
Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
sourcefn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
Attempts to write an entire buffer into this writer. Read more
sourcefn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>
write_all_vectored
)Attempts to write multiple buffers into this writer. Read more
Auto Trait Implementations
impl RefUnwindSafe for Stderr
impl Send for Stderr
impl Sync for Stderr
impl Unpin for Stderr
impl UnwindSafe for Stderr
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Downcast for T where
T: Any,
impl<T> Downcast for T where
T: Any,
sourcefn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>ⓘNotable traits for Box<W, Global>impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>ⓘNotable traits for Box<W, Global>impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
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
sourcefn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
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
sourcefn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read more
sourcefn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
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
sourceimpl<T> DowncastSync for T where
T: Any + Send + Sync,
impl<T> DowncastSync for T where
T: Any + Send + Sync,
sourceimpl<A> DynCastExt for A
impl<A> DynCastExt for A
sourcefn dyn_cast<T>(
self
) -> Result<<A as DynCastExtHelper<T>>::Target, <A as DynCastExtHelper<T>>::Source> where
A: DynCastExtHelper<T>,
T: ?Sized,
fn dyn_cast<T>(
self
) -> Result<<A as DynCastExtHelper<T>>::Target, <A as DynCastExtHelper<T>>::Source> where
A: DynCastExtHelper<T>,
T: ?Sized,
Use this to cast from one trait object type to another. Read more
sourcefn dyn_upcast<T>(self) -> <A as DynCastExtAdvHelper<T, T>>::Target where
A: DynCastExtAdvHelper<T, T, Source = <A as DynCastExtAdvHelper<T, T>>::Target>,
T: ?Sized,
fn dyn_upcast<T>(self) -> <A as DynCastExtAdvHelper<T, T>>::Target where
A: DynCastExtAdvHelper<T, T, Source = <A as DynCastExtAdvHelper<T, T>>::Target>,
T: ?Sized,
Use this to upcast a trait to one of its supertraits. Read more
sourcefn dyn_cast_adv<F, T>(
self
) -> Result<<A as DynCastExtAdvHelper<F, T>>::Target, <A as DynCastExtAdvHelper<F, T>>::Source> where
A: DynCastExtAdvHelper<F, T>,
F: ?Sized,
T: ?Sized,
fn dyn_cast_adv<F, T>(
self
) -> Result<<A as DynCastExtAdvHelper<F, T>>::Target, <A as DynCastExtAdvHelper<F, T>>::Source> where
A: DynCastExtAdvHelper<F, T>,
F: ?Sized,
T: ?Sized,
sourcefn 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>,
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
impl<T> RmpWrite for T where
T: Write,
impl<T> RmpWrite for T where
T: Write,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
fn vzip(self) -> V
impl<W> WriteBytesExt for W where
W: Write + ?Sized,
impl<W> WriteBytesExt for W where
W: Write + ?Sized,
fn write_u8(&mut self, n: u8) -> Result<(), Error>
fn write_u8(&mut self, n: u8) -> Result<(), Error>
Writes an unsigned 8 bit integer to the underlying writer. Read more
fn write_i8(&mut self, n: i8) -> Result<(), Error>
fn write_i8(&mut self, n: i8) -> Result<(), Error>
Writes a signed 8 bit integer to the underlying writer. Read more
fn write_u16<T>(&mut self, n: u16) -> Result<(), Error> where
T: ByteOrder,
fn write_u16<T>(&mut self, n: u16) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned 16 bit integer to the underlying writer. Read more
fn write_i16<T>(&mut self, n: i16) -> Result<(), Error> where
T: ByteOrder,
fn write_i16<T>(&mut self, n: i16) -> Result<(), Error> where
T: ByteOrder,
Writes a signed 16 bit integer to the underlying writer. Read more
fn write_u24<T>(&mut self, n: u32) -> Result<(), Error> where
T: ByteOrder,
fn write_u24<T>(&mut self, n: u32) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned 24 bit integer to the underlying writer. Read more
fn write_i24<T>(&mut self, n: i32) -> Result<(), Error> where
T: ByteOrder,
fn write_i24<T>(&mut self, n: i32) -> Result<(), Error> where
T: ByteOrder,
Writes a signed 24 bit integer to the underlying writer. Read more
fn write_u32<T>(&mut self, n: u32) -> Result<(), Error> where
T: ByteOrder,
fn write_u32<T>(&mut self, n: u32) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned 32 bit integer to the underlying writer. Read more
fn write_i32<T>(&mut self, n: i32) -> Result<(), Error> where
T: ByteOrder,
fn write_i32<T>(&mut self, n: i32) -> Result<(), Error> where
T: ByteOrder,
Writes a signed 32 bit integer to the underlying writer. Read more
fn write_u48<T>(&mut self, n: u64) -> Result<(), Error> where
T: ByteOrder,
fn write_u48<T>(&mut self, n: u64) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned 48 bit integer to the underlying writer. Read more
fn write_i48<T>(&mut self, n: i64) -> Result<(), Error> where
T: ByteOrder,
fn write_i48<T>(&mut self, n: i64) -> Result<(), Error> where
T: ByteOrder,
Writes a signed 48 bit integer to the underlying writer. Read more
fn write_u64<T>(&mut self, n: u64) -> Result<(), Error> where
T: ByteOrder,
fn write_u64<T>(&mut self, n: u64) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned 64 bit integer to the underlying writer. Read more
fn write_i64<T>(&mut self, n: i64) -> Result<(), Error> where
T: ByteOrder,
fn write_i64<T>(&mut self, n: i64) -> Result<(), Error> where
T: ByteOrder,
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.
fn write_uint<T>(&mut self, n: u64, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
fn write_uint<T>(&mut self, n: u64, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned n-bytes integer to the underlying writer. Read more
fn write_int<T>(&mut self, n: i64, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
fn write_int<T>(&mut self, n: i64, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
Writes a signed n-bytes integer to the underlying writer. Read more
fn write_uint128<T>(&mut self, n: u128, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
fn write_uint128<T>(&mut self, n: u128, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
Writes an unsigned n-bytes integer to the underlying writer. Read more
fn write_int128<T>(&mut self, n: i128, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
fn write_int128<T>(&mut self, n: i128, nbytes: usize) -> Result<(), Error> where
T: ByteOrder,
Writes a signed n-bytes integer to the underlying writer. Read more