pub struct Stdin { /* private fields */ }
Expand description
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 Considerations
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.
In a process with a detached console, such as one using
#![windows_subsystem = "windows"]
, or in a child process spawned from such a process,
the contained handle will be null. In such cases, the standard library’s Read
and
Write
will do nothing and silently succeed. All other I/O operations, via the
standard library or via raw Windows API calls, will fail.
Examples
use std::io;
fn main() -> io::Result<()> {
let mut buffer = String::new();
let mut stdin = io::stdin(); // We get `Stdin` here.
stdin.read_line(&mut buffer)?;
Ok(())
}
RunImplementations
sourceimpl Stdin
impl Stdin
sourcepub fn lock(&self) -> StdinLock<'static>ⓘNotable traits for StdinLock<'_>impl Read for StdinLock<'_>
pub fn lock(&self) -> StdinLock<'static>ⓘNotable traits for StdinLock<'_>impl Read for StdinLock<'_>
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, BufRead};
fn main() -> io::Result<()> {
let mut buffer = String::new();
let stdin = io::stdin();
let mut handle = stdin.lock();
handle.read_line(&mut buffer)?;
Ok(())
}
Runsourcepub fn read_line(&self, buf: &mut String) -> Result<usize>
pub fn read_line(&self, buf: &mut String) -> Result<usize>
Locks this handle and reads a line of input, appending it to 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!("{n} bytes read");
println!("{input}");
}
Err(error) => println!("error: {error}"),
}
RunYou 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
1.62.0 · sourcepub fn lines(self) -> Lines<StdinLock<'static>>ⓘNotable traits for Lines<B>impl<B: BufRead> Iterator for Lines<B> type Item = Result<String>;
pub fn lines(self) -> Lines<StdinLock<'static>>ⓘNotable traits for Lines<B>impl<B: BufRead> Iterator for Lines<B> type Item = Result<String>;
Consumes this handle and returns an iterator over input lines.
For detailed semantics of this method, see the documentation on
BufRead::lines
.
Examples
use std::io;
let lines = io::stdin().lines();
for line in lines {
println!("got a line: {}", line.unwrap());
}
RunTrait Implementations
sourceimpl AsFd for Stdin
impl AsFd for Stdin
sourcefn as_fd(&self) -> BorrowedFd<'_>
fn as_fd(&self) -> BorrowedFd<'_>
Borrows the file descriptor. Read more
sourceimpl AsHandle for Stdin
Available on Windows only.
impl AsHandle for Stdin
1.21.0 · sourceimpl AsRawHandle for Stdin
Available on Windows only.
impl AsRawHandle for Stdin
sourcefn as_raw_handle(&self) -> RawHandle
fn as_raw_handle(&self) -> RawHandle
Extracts the raw handle. Read more
sourceimpl Read for Stdin
impl Read for Stdin
sourcefn read(&mut self, buf: &mut [u8]) -> Result<usize>
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
sourcefn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>
Like read
, except that it reads into a slice of buffers. Read more
sourcefn is_read_vectored(&self) -> bool
fn is_read_vectored(&self) -> bool
Determines if this Read
er has an efficient read_vectored
implementation. Read more
sourcefn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>
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
sourcefn read_to_string(&mut self, buf: &mut String) -> Result<usize>
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
sourcefn read_exact(&mut self, buf: &mut [u8]) -> Result<()>
fn read_exact(&mut self, buf: &mut [u8]) -> Result<()>
Read the exact number of bytes required to fill buf
. Read more
sourcefn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<()>
fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<()>
Pull some bytes from this source into the specified buffer. Read more
sourcefn read_buf_exact(&mut self, buf: &mut ReadBuf<'_>) -> Result<()>
fn read_buf_exact(&mut self, buf: &mut ReadBuf<'_>) -> Result<()>
Read the exact number of bytes required to fill buf
. Read more
sourcefn by_ref(&mut self) -> &mut Self where
Self: Sized,
fn by_ref(&mut self) -> &mut Self where
Self: Sized,
Creates a “by reference” adaptor for this instance of Read
. Read more
sourcefn bytes(self) -> Bytes<Self>ⓘNotable traits for Bytes<R>impl<R: Read> Iterator for Bytes<R> type Item = Result<u8>;
where
Self: Sized,
fn bytes(self) -> Bytes<Self>ⓘNotable traits for Bytes<R>impl<R: Read> Iterator for Bytes<R> type Item = Result<u8>;
where
Self: Sized,
Auto Trait Implementations
impl RefUnwindSafe for Stdin
impl Send for Stdin
impl Sync for Stdin
impl Unpin for Stdin
impl UnwindSafe for Stdin
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more