Rust 1.87.0 Release

// This example demonstrates the new std::io::pipe API.
// It does not compile on Rust 1.98.1 because io::pipe was added in 1.87.0.
// To run it, use rustc 1.87.0 or later.

use std::io::{self, Read};
use std::process::Command;

fn main() -> io::Result<()> {
    // Create an anonymous pipe.
    let (mut reader, writer) = io::pipe()?;

    // Spawn a child process that writes to both stdout and stderr.
    let mut child = Command::new("sh")
        .arg("-c")
        .arg("echo out; echo err 1>&2")
        .stdout(writer.try_clone()?) // send stdout to the pipe
        .stderr(writer)              // send stderr to the pipe
        .spawn()?;

    // Read all output from the pipe.
    let mut output = Vec::new();
    reader.read_to_end(&mut output)?;

    // Wait for the child to finish.
    child.wait()?;

    // Print what we captured.
    println!("Captured output:\n{}", String::from_utf8_lossy(&output));
    Ok(())
}