title: O_RDWR permission denied
body: <p>I created this file</p>
  
  <pre><code>char *output = "big";
  creat(output, O_RDWR);
  </code></pre>
  
  <p>When I'm trying to read the file</p>
  
  <pre><code> cat big
  </code></pre>
  
  <p>I'm getting permission denied. Whats wrong with my code? How to create a file with read and write permission mode?</p>
  
  <p>with ls -l, the permission of big looked like this</p>
  
  <pre><code>----------
  </code></pre>
  
  <p>what does this mean?</p>