title: How to fix "Undefined ReadFile"
body: <p>I am going to use <a href="http://golang.org/pkg/io/ioutil/#ReadFile" rel="nofollow">ReadFile</a>:</p>
  
  <pre><code>package main
  
  import (
     "fmt"
     "io/ioutil"
  )
  
  func main() {
     ReadFile("data.txt")
  }
  
  &gt;&gt; undefined: ReadFile
  </code></pre>
  
  <p>How can I fix it?</p>