Struct Stderr 

pub struct Stderr(/* private fields */);

Available on crate features std and default only.

A handle to the standard error of the current process.

This writer is created by the stderr function. See its documentation for more.

Note: Windows Portability Consideration

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.

Implementations

impl Stderr

pub async fn lock(&self) -> StderrLock<'static>

Available on unstable only.

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 async_std::io;
use async_std::prelude::*;

let stderr = io::stderr();
let mut handle = stderr.lock().await;

handle.write_all(b"hello world").await?;

Trait Implementations

impl AsRawFd for Stderr

Available on Unix only.

fn as_raw_fd(&self) -> RawFd

Available on crate features std and docs only.

Extracts the raw file descriptor.

impl AsRawHandle for Stderr

Available on Windows only.

fn as_raw_handle(&self) -> RawHandle

Available on crate features std and docs only.

Extracts the raw handle, without taking any ownership.

impl Debug for Stderr

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Write for Stderr

fn poll_write( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize>>

Available on crate feature docs only.

Attempt to write bytes from buf into the object.

fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Available on crate feature docs only.

Attempt to flush the object, ensuring that any buffered data reach their destination.

fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Available on crate feature docs only.

Attempt to close the object.

fn poll_write_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize>>

Available on crate feature docs only.

Attempt to write bytes from bufs into the object using vectored IO operations.

fn write<'a>(&'a mut self, buf: &'a [u8]) -> ImplFuture<Result<usize>>

where Self: Unpin,

Available on crate feature docs only.

Writes some bytes into the byte stream.

fn flush(&mut self) -> ImplFuture<Result<()>>

where Self: Unpin,

Available on crate feature docs only.

Flushes the stream to ensure that all buffered contents reach their destination.

fn write_vectored<'a>( &'a mut self, bufs: &'a [IoSlice<'a>], ) -> ImplFuture<Result<usize>>

where Self: Unpin,

Available on crate feature docs only.

Like write, except that it writes from a slice of buffers.

fn write_all<'a>(&'a mut self, buf: &'a [u8]) -> ImplFuture<Result<()>>

where Self: Unpin,

Available on crate feature docs only.

Writes an entire buffer into the byte stream.

fn write_fmt<'a>(&'a mut self, fmt: Arguments<'_>) -> ImplFuture<Result<()>>

where Self: Unpin,

Available on crate feature docs only.

Writes a formatted string into this writer, returning any error encountered.