title: permission denied using vim in linux
body: <p>How do I change the user back to user space instead of root?</p>
  
  <p>I accidentally edit my code as root and then the user name changes from "yuki" to "root".  After that, I could not edit my code as "yuki" anymore...</p>
  
  <p>before:</p>
  
  <pre><code>-rw-rw-r--. 1 yuki yuki  5777 Apr 10 14:24 Makefile
  </code></pre>
  
  <p>after:</p>
  
  <pre><code>-rw-r--r--. 1 root    root     5828 Apr 24 19:42 Makefile
  </code></pre>
  
  <p>Could someone please help?</p>
  
  <p>Thanks.</p>