结构体 Stdout 

pub struct Stdout { /* private fields */ }

进程标准输出流的句柄。

对 stdout 的并发写入必须谨慎执行： 只有此 AsyncWrite 上的单个写入才保证是完整的。 尤其是要注意，使用 write_all 进行的写入 不能保证作为单次写入发生， 因此多个线程使用 write_all 写入数据可能会导致输出交错。

由 stdout 函数创建。

示例

use tokio::io::{self, AsyncWriteExt};

#[tokio::main]
async fn main() -> io::Result<()> {
    let mut stdout = io::stdout();
    stdout.write_all(b"Hello world!").await?;
    Ok(())
}

以下是在循环中使用 stdio 的示例。

use tokio::io::{self, AsyncWriteExt};

#[tokio::main]
async fn main() {
    let messages = vec!["hello", " world\n"];

    // When you use `stdio` in a loop, it is recommended to create
    // a single `stdio` instance outside the loop and call a write
    // operation against that instance on each loop.
    //
    // Repeatedly creating `stdout` instances inside the loop and
    // writing to that handle could result in mangled output since
    // each write operation is handled by a different blocking thread.
    let mut stdout = io::stdout();

    for message in &messages {
        stdout.write_all(message.as_bytes()).await.unwrap();
        stdout.flush().await.unwrap();
    }
}

Trait 实现

impl AsHandle for Stdout

Available on docsrs, or Windows only.

fn as_handle(&self) -> BorrowedHandle<'_>

Borrows the handle. 更多信息

impl AsRawHandle for Stdout

Available on docsrs, or Windows only.

fn as_raw_handle(&self) -> RawHandle

Extracts the raw handle. 更多信息

impl AsyncWrite for Stdout

fn poll_write( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize>>

Attempt to write bytes from buf into the object. 更多信息

fn poll_flush( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>

Attempts to flush the object, ensuring that any buffered data reach their destination. 更多信息

fn poll_shutdown( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>

Initiates or attempts to shut down this writer, returning success when the I/O connection has completely shut down. 更多信息

fn poll_write_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize>>

Like poll_write, except that it writes from a slice of buffers. 更多信息

fn is_write_vectored(&self) -> bool

Determines if this writer has an efficient poll_write_vectored implementation. 更多信息

impl Debug for Stdout

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

使用给定的格式化器格式化此值。 更多信息