// Copyright 2010 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package io

import "os"

type multiWriter struct {
	writers []Writer
}

func (t *multiWriter) Write(p []byte) (n int, err os.Error) {
	for _, w := range t.writers {
		n, err = w.Write(p)
		if err != nil {
			return
		}
		if n != len(p) {
			err = ErrShortWrite
			return
		}
	}
	return len(p), nil
}

// MultiWriter creates a writer that duplicates its writes to all the
// provided writers, similar to the Unix tee(1) command.
func MultiWriter(writers ...Writer) Writer {
	return &multiWriter{writers}
}