Struct PipeReader

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

Available on crate feature std only.

Read end of an anonymous pipe.

Implementations

impl PipeReader

pub fn try_clone(&self) -> Result<PipeReader, Error>

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

impl AsFd for PipeReader

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

Borrows the file descriptor.

impl AsRawFd for PipeReader

fn as_raw_fd(&self) -> i32

Extracts the raw file descriptor.

impl Debug for PipeReader

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

Formats the value using the given formatter.

impl From<OwnedFd> for PipeReader

fn from(owned_fd: OwnedFd) -> PipeReader

Converts to this type from the input type.

impl FromRawFd for PipeReader

unsafe fn from_raw_fd(raw_fd: i32) -> PipeReader

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

impl IntoRawFd for PipeReader

fn into_raw_fd(self) -> i32

Consumes this object, returning the raw underlying file descriptor.

impl Read for &PipeReader

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

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

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

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)

Determines if this Reader has an efficient read_vectored implementation.

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

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

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

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

Pull some bytes from this source into the specified buffer.

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

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

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

Reads the exact number of bytes required to fill buf.

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

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

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

where R: Read, 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.

impl Read for PipeReader

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

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

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

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)

Determines if this Reader has an efficient read_vectored implementation.

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

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

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

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

Pull some bytes from this source into the specified buffer.

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

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

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

Reads the exact number of bytes required to fill buf.

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

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

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

where R: Read, 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.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 4 bytes