Struct std::process::ChildStderr

pub struct ChildStderr { /* private fields */ }

A handle to a child process’s stderr.

This struct is used in the stderr field on Child.

When an instance of ChildStderr is dropped, the ChildStderr’s underlying file handle will be closed.

Trait Implementations

impl AsFd for ChildStderr

Available on Unix only.

fn as_fd(&self) -> BorrowedFd<'_>

Borrows the file descriptor.

impl AsHandle for ChildStderr

Available on Windows only.

fn as_handle(&self) -> BorrowedHandle<'_>

Borrows the handle.

impl AsRawFd for ChildStderr

Available on Unix only.

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor.

impl AsRawHandle for ChildStderr

Available on Windows only.

fn as_raw_handle(&self) -> RawHandle

Extracts the raw handle.

impl Debug for ChildStderr

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

Formats the value using the given formatter.

impl From<ChildStderr> for OwnedFd

Available on Unix only.

fn from(child_stderr: ChildStderr) -> OwnedFd

Takes ownership of a ChildStderr’s file descriptor.

impl From<ChildStderr> for OwnedHandle

Available on Windows only.

fn from(child_stderr: ChildStderr) -> OwnedHandle

Takes ownership of a ChildStderr’s file handle.

impl From<ChildStderr> for Stdio

fn from(child: ChildStderr) -> Stdio

Converts a ChildStderr into a Stdio.

Examples

use std::process::{Command, Stdio};

let reverse = Command::new("rev")
    .arg("non_existing_file.txt")
    .stderr(Stdio::piped())
    .spawn()
    .expect("failed reverse command");

let cat = Command::new("cat")
    .arg("-")
    .stdin(reverse.stderr.unwrap()) // Converted into a Stdio here
    .output()
    .expect("failed echo command");

assert_eq!(
    String::from_utf8_lossy(&cat.stdout),
    "rev: cannot open non_existing_file.txt: No such file or directory\n"
);

impl From<OwnedFd> for ChildStderr

Available on Unix only.

Creates a ChildStderr from the provided OwnedFd.

The provided file descriptor must point to a pipe with the CLOEXEC flag set.

fn from(fd: OwnedFd) -> ChildStderr

Converts to this type from the input type.

impl From<OwnedHandle> for ChildStderr

Available on Windows only.

Creates a ChildStderr from the provided OwnedHandle.

The provided handle must be asynchronous, as reading and writing from and to it is implemented using asynchronous APIs.

fn from(handle: OwnedHandle) -> ChildStderr

Converts to this type from the input type.

impl IntoRawFd for ChildStderr

Available on Unix only.

fn into_raw_fd(self) -> RawFd

Consumes this object, returning the raw underlying file descriptor.

impl IntoRawHandle for ChildStderr

Available on Windows only.

fn into_raw_handle(self) -> RawHandle

Consumes this object, returning the raw underlying handle.

impl Read for ChildStderr

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)

Pull some bytes from this source into the specified buffer.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<()>

Reads the exact number of bytes required to fill buf.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R: Read>(self, next: R) -> Chain<Self, R>

where Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.