Module tokio::io

Asynchronous I/O.

This module is the asynchronous version of std::io. Primarily, it defines two traits, AsyncRead and AsyncWrite, which extend the Read and Write traits of the standard library.

AsyncRead and AsyncWrite

AsyncRead and AsyncWrite must only be implemented for non-blocking I/O types that integrate with the futures type system. In other words, these types must never block the thread, and instead the current task is notified when the I/O resource is ready.

Standard input and output

Tokio provides asynchronous APIs to standard input, output, and error. These APIs are very similar to the ones provided by std, but they also implement AsyncRead and AsyncWrite.

Unlike most other Tokio APIs, the standard input / output APIs must be used from the context of the Tokio runtime as they require Tokio specific features to function.

std re-exports

Additionally, Error, ErrorKind, and Result are re-exported from std::io for ease of use.

Structs

BufReader	The BufReader struct adds buffering to any reader.
BufWriter	Wraps a writer and buffers its output.
Error	The error type for I/O operations of the Read, Write, Seek, and associated traits.
Stderr	A handle to the standard error stream of a process.
Stdin	A handle to the standard input stream of a process.
Stdout	A handle to the standard output stream of a process.

Enums

ErrorKind

A list specifying general categories of I/O error.

Traits

AsyncBufRead	Read bytes asynchronously.
AsyncBufReadExt	An extension trait which adds utility methods to AsyncBufRead types.
AsyncRead	Read bytes asynchronously.
AsyncReadExt	An extension trait which adds utility methods to AsyncRead types.
AsyncWrite	Writes bytes asynchronously.
AsyncWriteExt	An extension trait which adds utility methods to AsyncWrite types.

Functions

split	Split a single value implementing AsyncRead + AsyncWrite into separate AsyncRead and AsyncWrite handles.
stderr	Constructs a new handle to the standard error of the current process.
stdin	Constructs a new handle to the standard input of the current process.
stdout	Constructs a new handle to the standard output of the current process.

Type Definitions

Result

A specialized Result type for I/O operations.