ttyin.rs

extern crate nix;

use std::io;
use std::io::BufRead;

/// switch stdin to key input
fn ttyin() -> io::Result<()> {
    use std::fs::File;
    use nix::unistd;
    use std::os::unix::io::AsRawFd;
    let file = File::open("/dev/tty")?;
    let _ = unistd::dup2(file.as_raw_fd(), io::stdin().as_raw_fd());
    Ok(())
}

fn main() -> io::Result<()> {
    let inp = io::stdin();
    let mut inp = inp.lock();
    let mut s = String::new();

    // print out from stdin(tty or pipe)
    let _ = inp.read_line(&mut s);
    println!("stdin:[{}]", s);
    s.clear();

    ttyin()?;

    // print out from stdin(tty)
    let _ = inp.read_line(&mut s);
    println!("stdin:[{}]", s);
    Ok(())
}