title: fopen() search paths
body: <p>Is there a way to set a search path for fopen() so that when I just enter the filename, it searches these path(s) for this file?</p>
  
  <pre><code>f=fopen("xxx","r");
  </code></pre>
  
  <p>I just want xxx not to be in the current directory, and I dont want to change the source code.</p>