Stdin in std::io - Rust (original) (raw)
Struct Stdin
1.0.0 · Source
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 andWrite 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 stdin = io::stdin(); // We get `Stdin` here.
stdin.read_line(&mut buffer)?;
Ok(())
}1.0.0 · Source
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(())
}1.0.0 · Source
Locks this handle and reads a line of input, appending it to the specified buffer.
For detailed semantics of this method, see the documentation onBufRead::read_line. In particular:
- Previous content of the buffer will be preserved. To avoid appending to the buffer, you need to clear it first.
- The trailing newline character, if any, is included in the buffer.
§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}"),
}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
1.62.0 · Source
Consumes this handle and returns an iterator over input lines.
For detailed semantics of this method, see the documentation onBufRead::lines.
§Examples
use std::io;
let lines = io::stdin().lines();
for line in lines {
println!("got a line: {}", line.unwrap());
}Available on Windows only.
Available on Windows only.
Returns true if the descriptor/handle refers to a terminal/tty. Read more
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
🔬This is a nightly-only experimental API. (read_buf #78485)
Pull some bytes from this source into the specified buffer. Read more
Like read, except that it reads into a slice of buffers. Read more
🔬This is a nightly-only experimental API. (can_vector #69941)
Determines if this Reader has an efficient read_vectoredimplementation. Read more
Reads all bytes until EOF in this source, placing them into buf. Read more
Reads all bytes until EOF in this source, appending them to buf. Read more
Reads the exact number of bytes required to fill buf. Read more
🔬This is a nightly-only experimental API. (read_buf #78485)
Reads the exact number of bytes required to fill cursor. Read more
Creates a “by reference” adaptor for this instance of Read. Read more
Transforms this Read instance to an Iterator over its bytes. Read more
Creates an adapter which will chain this stream with another. Read more
Creates an adapter which will read at most limit bytes from it. Read more
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
🔬This is a nightly-only experimental API. (read_buf #78485)
Pull some bytes from this source into the specified buffer. Read more
Like read, except that it reads into a slice of buffers. Read more
🔬This is a nightly-only experimental API. (can_vector #69941)
Determines if this Reader has an efficient read_vectoredimplementation. Read more
Reads all bytes until EOF in this source, placing them into buf. Read more
Reads all bytes until EOF in this source, appending them to buf. Read more
Reads the exact number of bytes required to fill buf. Read more
🔬This is a nightly-only experimental API. (read_buf #78485)
Reads the exact number of bytes required to fill cursor. Read more
Creates a “by reference” adaptor for this instance of Read. Read more
Transforms this Read instance to an Iterator over its bytes. Read more
Creates an adapter which will chain this stream with another. Read more
Creates an adapter which will read at most limit bytes from it. Read more