title: Which directories does include statement search in C/C++?
body: <p><code>test.c</code>:</p>
  
  <pre><code>#include "file.h"
  </code></pre>
  
  <p>In the above statement, which directories will be searched ?</p>
  
  <p>I suppose the directory where <code>test.c</code> locates will be searched, right?</p>
  
  <p>But is that all?</p>
  
  <p>BTW, what's the benefit to use a header file? Java doesn't require a header file...</p>