# Struct std::process::ChildStdout

1.0.0 · source ·

    pub struct ChildStdout { /* private fields */ }

Expand description

A handle to a child process’s standard output (stdout).

This struct is used in the `stdout` field on `Child`.

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

## Trait Implementations§

1.63.0 · source§

### impl AsFd for ChildStdout

Available on Unix only.
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#### fn as_fd(&self) -> BorrowedFd<'_>

Borrows the file descriptor. Read more
1.63.0 · source§

### impl AsHandle for ChildStdout

Available on Windows only.
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#### fn as_handle(&self) -> BorrowedHandle<'_>

Borrows the handle. Read more
1.2.0 · source§

### impl AsRawFd for ChildStdout

Available on Unix only.
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#### fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor. Read more
1.2.0 · source§

### impl AsRawHandle for ChildStdout

Available on Windows only.
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#### fn as_raw_handle(&self) -> RawHandle

Extracts the raw handle. Read more
1.16.0 · source§

### impl Debug for ChildStdout

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

Formats the value using the given formatter. Read more
1.63.0 · source§

### impl From<ChildStdout> for OwnedFd

Available on Unix only.
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#### fn from(child_stdout: ChildStdout) -> OwnedFd

Converts to this type from the input type.
1.63.0 · source§

### impl From<ChildStdout> for OwnedHandle

Available on Windows only.
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#### fn from(child_stdout: ChildStdout) -> OwnedHandle

Converts to this type from the input type.
1.20.0 · source§

### impl From<ChildStdout> for Stdio

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#### fn from(child: ChildStdout) -> Stdio

Converts a `ChildStdout` into a `Stdio`.

##### Examples

`ChildStdout` will be converted to `Stdio` using `Stdio::from` under the hood.

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

    let hello = Command::new("echo")
        .arg("Hello, world!")
        .stdout(Stdio::piped())
        .spawn()
        .expect("failed echo command");

    let reverse = Command::new("rev")
        .stdin(hello.stdout.unwrap())  // Converted into a Stdio here
        .output()
        .expect("failed reverse command");

    assert_eq!(reverse.stdout, b"!dlrow ,olleH\n");

Run
1.74.0 · source§

### impl From<OwnedFd> for ChildStdout

Available on Unix only.

Create a `ChildStdout` from the provided `OwnedFd`.

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

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#### fn from(fd: OwnedFd) -> ChildStdout ⓘ

Converts to this type from the input type.
1.74.0 · source§

### impl From<OwnedHandle> for ChildStdout

Available on Windows only.

Create a `ChildStdout` from the provided `OwnedHandle`.

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

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#### fn from(handle: OwnedHandle) -> ChildStdout ⓘ

Converts to this type from the input type.
1.4.0 · source§

### impl IntoRawFd for ChildStdout

Available on Unix only.
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#### fn into_raw_fd(self) -> RawFd

Consumes this object, returning the raw underlying file descriptor. Read more
1.4.0 · source§

### impl IntoRawHandle for ChildStdout

Available on Windows only.
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#### fn into_raw_handle(self) -> RawHandle

Consumes this object, returning the raw underlying handle. Read more
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### impl Read for ChildStdout

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

Like `read`, except that it reads into a slice of buffers. Read more
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#### fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (`can_vector` #69941)
Determines if this `Read`er has an efficient `read_vectored` implementation. Read more
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#### fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>

Read all bytes until EOF in this source, placing them into `buf`. Read more
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#### fn read_to_string(&mut self, buf: &mut String) -> Result<usize>

Read all bytes until EOF in this source, appending them to `buf`. Read more
1.6.0 · source§

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

Read the exact number of bytes required to fill `buf`. Read more
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#### fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (`read_buf` #78485)
Read the exact number of bytes required to fill `cursor`. Read more
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#### fn by_ref(&mut self) -> &mut Self where Self: Sized,

Creates a “by reference” adaptor for this instance of `Read`. Read more
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#### fn bytes(self) -> Bytes<Self> ⓘwhere Self: Sized,

Transforms this `Read` instance to an `Iterator` over its bytes. Read more
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#### 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
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#### fn take(self, limit: u64) -> Take<Self> ⓘwhere Self: Sized,

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

## Auto Trait Implementations§

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### impl RefUnwindSafe for ChildStdout

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### impl Send for ChildStdout

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### impl Sync for ChildStdout

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### impl Unpin for ChildStdout

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### impl UnwindSafe for ChildStdout

## Blanket Implementations§

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

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
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### impl<T> Borrow<T> for Twhere T: ?Sized,

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#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for Twhere T: ?Sized,

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

Mutably borrows from an owned value. Read more
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### impl<T> From<T> for T

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#### fn from(t: T) -> T

Returns the argument unchanged.

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

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#### fn into(self) -> U

Calls `U::from(self)`.

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

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

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#### type Error = Infallible

The type returned in the event of a conversion error.
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#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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### impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.