# termion-input-tokio
An adapter that exposes termion's input and key event iterators as asynchronous streams.
## Compatiblity
Compatible with Tokio v1.0.
## Usage
```rust
use futures::StreamExt;
use std::future;
use termion::{event::Key, raw::IntoRawMode};
use termion_input_tokio::TermReadAsync;
#[tokio::main]
async fn main() -> Result<(), std::io::Error> {
// Disable line buffering, local echo, etc.
let _raw_term = std::io::stdout().into_raw_mode()?;
tokio::io::stdin()
.keys_stream()
// End the stream when 'q' is pressed.
.take_while(|event| {
future::ready(match event {
Ok(Key::Char('q')) => false,
_ => true,
})
})
// Print each key that was pressed.
.for_each(|event| async move {
println!("{:?}\r", event);
})
.await;
Ok(())
}
```
## Non-blocking Input
It is challenging to use true non-blocking reads with `stdin`. In the common case both `stdin` and `stdout` refer to the same file, typically a PTY. Since non-blocking mode is a per-file property, rather than a per-file-descriptor one, using `fcntl` with `O_NONBLOCK` to change `stdin` into non-blocking mode will also make `stdout` non-blocking. Since most code is not prepared to deal with `EWOULDBLOCK` when writing to `stdout`, asynchronous reads from `stdin` are typically typically performed using blocking operations on a secondary thread. This is how `AsyncRead` for [tokio::io::stdin()](https://docs.rs/tokio/latest/tokio/io/fn.stdin.html) is implemented.
## Credits
This is based on [termion-tokio](https://github.com/katyo/termion-tokio) by [Kayo Phoenix](https://github.com/katyo), which is in turn based on code within [termion](https://github.com/redox-os/termion).