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/Rust

Struct PipeReader

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

Read end of an anonymous pipe.

Implementations

impl PipeReader

1.87.0Source

pub fn try_clone(&self) -> Result<Self>

Creates a new PipeReader instance that shares the same underlying file description.

Examples

use std::fs;
use std::io::{pipe, Write};
use std::process::Command;
const NUM_SLOT: u8 = 2;
const NUM_PROC: u8 = 5;
const OUTPUT: &str = "work.txt";

let mut jobs = vec![];
let (reader, mut writer) = pipe()?;

// Write NUM_SLOT characters the pipe.
writer.write_all(&[b'|'; NUM_SLOT as usize])?;

// Spawn several processes that read a character from the pipe, do some work, then
// write back to the pipe. When the pipe is empty, the processes block, so only
// NUM_SLOT processes can be working at any given time.
for _ in 0..NUM_PROC {
    jobs.push(
        Command::new("bash")
            .args(["-c",
                &format!(
                     "read -n 1\n\
                      echo -n 'x' >> '{OUTPUT}'\n\
                      echo -n '|'",
                ),
            ])
            .stdin(reader.try_clone()?)
            .stdout(writer.try_clone()?)
            .spawn()?,
    );
}

// Wait for all jobs to finish.
for mut job in jobs {
    job.wait()?;
}

// Check our work and clean up.
let xs = fs::read_to_string(OUTPUT)?;
fs::remove_file(OUTPUT)?;
assert_eq!(xs, "x".repeat(NUM_PROC.into()));

Trait Implementations

1.87.0Source

impl AsFd for PipeReaderAvailable on (Unix or HermitCore or target_os=trusty or WASI or target_os=motor) and non-target_os=trusty only.

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

Borrows the file descriptor. Read more

1.87.0Source

impl AsHandle for PipeReaderAvailable on Windows only.

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

Borrows the handle. Read more

1.87.0Source

impl AsRawFd for PipeReaderAvailable on (Unix or HermitCore or target_os=trusty or WASI or target_os=motor) and non-target_os=trusty only.

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor. Read more

1.87.0Source

impl AsRawHandle for PipeReaderAvailable on Windows only.

fn as_raw_handle(&self) -> RawHandle

Extracts the raw handle. Read more

1.87.0Source

impl Debug for PipeReader

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

Formats the value using the given formatter. Read more

1.87.0Source

impl From<OwnedFd> for PipeReaderAvailable on (Unix or HermitCore or target_os=trusty or WASI or target_os=motor) and non-target_os=trusty only.

fn from(owned_fd: OwnedFd) -> Self

Converts to this type from the input type.

1.87.0Source

impl From<OwnedHandle> for PipeReaderAvailable on Windows only.

fn from(owned_handle: OwnedHandle) -> Self

Converts to this type from the input type.

1.87.0Source

impl From<PipeReader> for OwnedFdAvailable on (Unix or HermitCore or target_os=trusty or WASI or target_os=motor) and non-target_os=trusty only.

fn from(pipe: PipeReader) -> Self

Converts to this type from the input type.

1.87.0Source

impl From<PipeReader> for OwnedHandleAvailable on Windows only.

fn from(pipe: PipeReader) -> Self

Converts to this type from the input type.

1.87.0Source

impl From<PipeReader> for Stdio

fn from(pipe: PipeReader) -> Self

Converts to this type from the input type.

1.87.0Source

impl FromRawFd for PipeReaderAvailable on (Unix or HermitCore or target_os=trusty or WASI or target_os=motor) and non-target_os=trusty only.

unsafe fn from_raw_fd(raw_fd: RawFd) -> Self

Constructs a new instance of Self from the given raw file descriptor. Read more

1.87.0Source

impl FromRawHandle for PipeReaderAvailable on Windows only.

unsafe fn from_raw_handle(raw_handle: RawHandle) -> Self

Constructs a new I/O object from the specified raw handle. Read more

1.87.0Source

impl IntoRawFd for PipeReaderAvailable on (Unix or HermitCore or target_os=trusty or WASI or target_os=motor) and non-target_os=trusty only.

fn into_raw_fd(self) -> RawFd

Consumes this object, returning the raw underlying file descriptor. Read more

1.87.0Source

impl IntoRawHandle for PipeReaderAvailable on Windows only.

fn into_raw_handle(self) -> RawHandle

Consumes this object, returning the raw underlying handle. Read more

1.87.0Source

impl Read for &PipeReader

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. Read more

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

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

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. Read more

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

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

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. Read more

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

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

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

Reads the exact number of bytes required to fill buf. Read more

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. Read more

fn by_ref(&mut self) -> &mut Selfwhere
    Self: Sized,

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

fn bytes(self) -> Bytes<Self> ⓘwhere
    Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more

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

Creates an adapter which will chain this stream with another. Read more

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

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

fn read_array<const N: usize>(&mut self) -> Result<[u8; N]>where
    Self: Sized,

🔬This is a nightly-only experimental API. (read_array #148848)

Read and return a fixed array of bytes from this source. Read more

1.87.0Source

impl Read for PipeReader

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. Read more

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

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

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. Read more

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

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

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. Read more

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

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

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

Reads the exact number of bytes required to fill buf. Read more

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. Read more

fn by_ref(&mut self) -> &mut Selfwhere
    Self: Sized,

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

fn bytes(self) -> Bytes<Self> ⓘwhere
    Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more

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

Creates an adapter which will chain this stream with another. Read more

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

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

fn read_array<const N: usize>(&mut self) -> Result<[u8; N]>where
    Self: Sized,

🔬This is a nightly-only experimental API. (read_array #148848)

Read and return a fixed array of bytes from this source. Read more

Auto Trait Implementations

impl Freeze for PipeReader

impl RefUnwindSafe for PipeReader

impl Send for PipeReader

impl Sync for PipeReader

impl Unpin for PipeReader

impl UnwindSafe for PipeReader

Blanket Implementations

impl<T> Any for Twhere
    T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for Twhere
    T: ?Sized,

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for Twhere
    T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> From<T> for T

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> for Twhere
    U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<T, U> TryFrom<U> for Twhere
    U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/io/struct.PipeReader.html