Code shared from the Rust Playground

playground.rs

use std::process::{Command, Stdio};

fn main() {
    let mut rev = Command::new("rev")
        .stdin(Stdio::piped())
        .stdout(Stdio::inherit())
        .stderr(Stdio::inherit())
        .spawn()
        .expect("rev failed to spawn");

    let mut stdin: Stdio = rev.stdin.take().expect("rev had no stdin?").into();

    while Command::new("true")
        .status()
        .map(|status| status.success())
        .unwrap_or(false)
    {
        let mut fortune = Command::new("fortune")
            .stdin(Stdio::null())
            .stdout(stdin)
            .stderr(Stdio::inherit())
            .spawn()
            .expect("fortune failed to spawn");

        if !fortune
            .wait()
            .expect("waiting for fortune to finish failed")
            .success()
        {
            panic!("fortune failed??");
        }

        //  **************** But this next part will always fail, can't get the pipe back
        //  **************** have to use a third party library to call the `dup` / `dup2` syscall
        //  **************** directly.
        stdin = fortune
            .stdout
            .take()
            .expect("hey, fortune didn't give stdout back!")
            .into();
    }
}