// Package ioutil provides a WriteFile func with an io.Reader as input.
package ioutil

import (
	"io"
	"os"
)

// WriteFile copies from r to a file named by filename.
// If the file does not exist, WriteFile creates it with permissions 0644;
// otherwise WriteFile truncates it before writing.
func WriteFile(filename string, r io.Reader) error {
	f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
	if err != nil {
		return err
	}
	_, err = io.Copy(f, r)
	if err1 := f.Close(); err == nil {
		err = err1
	}
	return err
}