Printing Bytes Passing through a Pipe

logpipe.go

package main

import (
	"bufio"
	"io"
)

type LoggedPipe struct {
	Stdin  *io.PipeReader
	Stdout *PipeCloner
}

type PipeCloner struct {
	io.Writer
	Pipe *io.PipeWriter
}

func NewPipeCloner(p *io.PipeWriter) *PipeCloner {
	mw := io.MultiWriter(os.Stdout, p)
	c := &PipeCloner{bufio.NewWriter(mw), p}
	return c
}

func (p *PipeCloner) Close() error {
	return p.Pipe.Close()
}

func LoggedPipe() (*io.PipeReader, *PipeCloner) {
	p := new(LoggedPipe)
	r, w := io.Pipe()
	p.Stdin = r
	p.Stdout = NewPipeCloner(w)

	return p.Stdin, p.Stdout
}