sn11.go

package main

import (
	"bytes"
	"fmt"
	"io"
	"os"
)

// Your function
func foo(w *io.PipeWriter) {
	defer w.Close()
	// Write a message to pipe writer
	fmt.Fprintln(w, "Hello Medium")
}

func main() {
	// Create a pipe
	pr, pw := io.Pipe()

	// Pass writer to function
	go foo(pw)

	// Variable to get standard output of function
	var b bytes.Buffer

	// Create a multi writer that is a combination of
	// os.Stdout and our variable byte buffer
	mw := io.MultiWriter(os.Stdout, &b)
	// Copies reader content to standard output
	_, err := io.Copy(mw, pr)

	if err != nil {
		panic(err)
	}

	// Optional: verify data
	fmt.Println(b.String())
}