use futures::stream::Stream as _;
use std::io::Write as _;
fn main() {
env_logger::from_env(
env_logger::Env::default().default_filter_or("error"),
)
.init();
let (cmd, args) = if std::env::args().count() > 1 {
(
std::env::args().nth(1).unwrap(),
std::env::args().skip(2).collect(),
)
} else {
(
std::env::var("SHELL").unwrap_or_else(|_| "/bin/sh".to_string()),
vec![],
)
};
tokio::run(Passthrough::new(&cmd, &args));
}
struct Passthrough {
term: vt100::Parser,
process: tokio_pty_process_stream::ResizingProcess<Stdin>,
raw_screen: Option<crossterm::screen::RawScreen>,
alternate_screen: Option<crossterm::screen::AlternateScreen>,
done: bool,
}
impl Passthrough {
fn new(cmd: &str, args: &[String]) -> Self {
let input = Stdin::new();
let process = tokio_pty_process_stream::ResizingProcess::new(
tokio_pty_process_stream::Process::new(cmd, args, input),
);
Self {
term: vt100::Parser::default(),
process,
raw_screen: None,
alternate_screen: None,
done: false,
}
}
fn err<T: std::fmt::Display>(&mut self, e: T) {
self.alternate_screen = None;
self.raw_screen = None;
eprintln!("{}", e);
}
}
impl futures::future::Future for Passthrough {
type Item = ();
type Error = ();
fn poll(&mut self) -> futures::Poll<Self::Item, Self::Error> {
loop {
let event = futures::try_ready!(self
.process
.poll()
.map_err(|e| self.err(e)));
match event {
Some(tokio_pty_process_stream::Event::CommandStart {
..
}) => {
if self.raw_screen.is_none() {
self.raw_screen = Some(
crossterm::screen::RawScreen::into_raw_mode()
.map_err(|e| self.err(e))?,
);
}
if self.alternate_screen.is_none() {
self.alternate_screen = Some(
crossterm::screen::AlternateScreen::to_alternate(
false,
)
.map_err(|e| self.err(e))?,
);
}
write(&self.term.screen().contents_formatted())
.map_err(|e| self.err(e))?;
}
Some(tokio_pty_process_stream::Event::CommandExit {
..
}) => {
self.done = true;
}
Some(tokio_pty_process_stream::Event::Output { data }) => {
let screen = self.term.screen().clone();
self.term.process(&data);
write(&self.term.screen().contents_diff(&screen))
.map_err(|e| self.err(e))?;
write(&self.term.screen().input_mode_diff(&screen))
.map_err(|e| self.err(e))?;
write(&self.term.screen().title_diff(&screen))
.map_err(|e| self.err(e))?;
write(&self.term.screen().bells_diff(&screen))
.map_err(|e| self.err(e))?;
}
Some(tokio_pty_process_stream::Event::Resize {
size: (rows, cols),
}) => {
self.term.set_size(rows, cols);
}
None => {
if !self.done {
unreachable!()
}
return Ok(futures::Async::Ready(()));
}
}
}
}
}
fn write(data: &[u8]) -> std::io::Result<()> {
let stdout = std::io::stdout();
let mut stdout = stdout.lock();
stdout.write_all(data)?;
stdout.flush()?;
Ok(())
}
struct EventedStdin;
const STDIN: i32 = 0;
impl std::io::Read for EventedStdin {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
let stdin = std::io::stdin();
let mut stdin = stdin.lock();
stdin.read(buf)
}
}
impl mio::Evented for EventedStdin {
fn register(
&self,
poll: &mio::Poll,
token: mio::Token,
interest: mio::Ready,
opts: mio::PollOpt,
) -> std::io::Result<()> {
let fd = STDIN as std::os::unix::io::RawFd;
let eventedfd = mio::unix::EventedFd(&fd);
eventedfd.register(poll, token, interest, opts)
}
fn reregister(
&self,
poll: &mio::Poll,
token: mio::Token,
interest: mio::Ready,
opts: mio::PollOpt,
) -> std::io::Result<()> {
let fd = STDIN as std::os::unix::io::RawFd;
let eventedfd = mio::unix::EventedFd(&fd);
eventedfd.reregister(poll, token, interest, opts)
}
fn deregister(&self, poll: &mio::Poll) -> std::io::Result<()> {
let fd = STDIN as std::os::unix::io::RawFd;
let eventedfd = mio::unix::EventedFd(&fd);
eventedfd.deregister(poll)
}
}
pub struct Stdin {
input: tokio::reactor::PollEvented2<EventedStdin>,
}
impl Stdin {
pub fn new() -> Self {
Self::default()
}
}
impl Default for Stdin {
fn default() -> Self {
Self {
input: tokio::reactor::PollEvented2::new(EventedStdin),
}
}
}
impl std::io::Read for Stdin {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
self.input.read(buf)
}
}
impl tokio::io::AsyncRead for Stdin {
fn poll_read(
&mut self,
buf: &mut [u8],
) -> std::result::Result<futures::Async<usize>, tokio::io::Error> {
// XXX this is why i had to do the EventedFd thing - poll_read on its
// own will block reading from stdin, so i need a way to explicitly
// check readiness before doing the read
let ready = mio::Ready::readable();
match self.input.poll_read_ready(ready)? {
futures::Async::Ready(_) => {
let res = self.input.poll_read(buf);
// XXX i'm pretty sure this is wrong (if the single poll_read
// call didn't return all waiting data, clearing read ready
// state means that we won't get the rest until some more data
// beyond that appears), but i don't know that there's a way
// to do it correctly given that poll_read blocks
self.input.clear_read_ready(ready)?;
res
}
futures::Async::NotReady => Ok(futures::Async::NotReady),
}
}
}