std::io::Stdin - Rust
Description: API documentation for the Rust `Stdin` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, Stdin

# 1.0.0[−][src]Struct std::io::Stdin

    pub struct Stdin { /* fields omitted */ }

A handle to the standard input stream of a process.

Each handle is a shared reference to a global buffer of input data to this process. A handle can be `lock`'d to gain full access to `BufRead` methods (e.g., `.lines()`). Reads to this handle are otherwise locked with respect to other reads.

This handle implements the `Read` trait, but beware that concurrent reads of `Stdin` must be executed with care.

Created by the `io::stdin` method.

### 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 read bytes that are not valid UTF-8 will return an error.

## Methods

### `impl Stdin`[src]

####
ⓘImportant traits for StdinLock<'_>

### Important traits for StdinLock<'_>

`impl<'_> Read for StdinLock<'_>`
`pub fn lock(&self) -> StdinLock`[src]

Locks this handle to the standard input stream, returning a readable guard.

The lock is released when the returned lock goes out of scope. The returned guard also implements the `Read` and `BufRead` traits for accessing the underlying data.

# Examples

    use std::io::{self, Read};

    fn main() -> io::Result<()> {
        let mut buffer = String::new();
        let stdin = io::stdin();
        let mut handle = stdin.lock();

        handle.read_to_string(&mut buffer)?;
        Ok(())
    }Run

#### `pub fn read_line(&self, buf: &mut String) -> Result<usize>`[src]

Locks this handle and reads a line of input into the specified buffer.

For detailed semantics of this method, see the documentation on `BufRead::read_line`.

# Examples

    use std::io;

    let mut input = String::new();
    match io::stdin().read_line(&mut input) {
        Ok(n) => {
            println!("{} bytes read", n);
            println!("{}", input);
        }
        Err(error) => println!("error: {}", error),
    }Run

You can run the example one of two ways:

- Pipe some text to it, e.g., `printf foo | path/to/executable`
- Give it text interactively by running the executable directly, in which case it will wait for the Enter key to be pressed before continuing

## Trait Implementations

### `impl Read for Stdin`[src]

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

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>`[src]

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

#### `unsafe fn initializer(&self) -> Initializer`[src]

🔬 This is a nightly-only experimental API. (`read_initializer` #42788)

Determines if this `Read`er can work with buffers of uninitialized memory. Read more

#### `fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>`[src]

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

#### `fn read_to_string(&mut self, buf: &mut String) -> Result<usize>`[src]

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

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

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

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W`
`fn by_ref(&mut self) -> &mut Self where
Self: Sized,` [src]

Creates a "by reference" adaptor for this instance of `Read`. Read more

####
ⓘImportant traits for Bytes<R>

### Important traits for Bytes<R>

`impl<R: Read> Iterator for Bytes<R> type Item = Result<u8>;`
`fn bytes(self) -> Bytes<Self> where
Self: Sized,` [src]

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

####
ⓘImportant traits for Chain<T, U>

### Important traits for Chain<T, U>

`impl<T: Read, U: Read> Read for Chain<T, U>`
`fn chain<R: Read>(self, next: R) -> Chain<Self, R> where
Self: Sized,` [src]

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

####
ⓘImportant traits for Take<T>

### Important traits for Take<T>

`impl<T: Read> Read for Take<T>`
`fn take(self, limit: u64) -> Take<Self> where
Self: Sized,` [src]

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

### `impl AsRawFd for Stdin` 1.21.0[src]

#### `fn as_raw_fd(&self) -> RawFd`[src]

This is supported on Unix only.

Extracts the raw file descriptor. Read more

### `impl AsRawHandle for Stdin` 1.21.0[src]

#### `fn as_raw_handle(&self) -> RawHandle`[src]

This is supported on Windows only.

Extracts the raw handle, without taking any ownership.

### `impl Debug for Stdin` 1.16.0[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result`[src]

Formats the value using the given formatter. Read more

## Auto Trait Implementations

### `impl Send for Stdin`

### `impl Sync for Stdin`

## Blanket Implementations

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `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>`[src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `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>`[src]

Performs the conversion.

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W`
`fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W`
`fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more

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