how to get stderr

[RickSKy]

Is there any example to get stderr for expect?

[zhiburt]

Hi @RickSKy
Thank you for the question.

As far as I understand the question you what to read from stderr right?

expect reads from stdout and stderr simultaneously so there's only 1 way I know how to do it.
You need to turn of stdout.
See this example.

use std::process::Stdio;

use expectrl::{Error, Session, WaitStatus};

fn main() -> Result<(), Error> {
    let mut cmd = std::process::Command::new("sh");
    cmd.arg("-c").arg("echo print to stdout && echo print to stderr >&2");

    // turn off stdout
    cmd.stdout(Stdio::null());

    let mut p = Session::spawn(cmd)?;

    let line = p.expect('\n')?;
    println!("{:?}", String::from_utf8_lossy(line.as_bytes()));

    let line = p.expect('\n')?;
    println!("{:?}", String::from_utf8_lossy(line.as_bytes()));

    assert_eq!(p.wait().unwrap(), WaitStatus::Exited(p.pid(), 0));

    Ok(())
}

Am I addressed you question?