title: set_include_path(get_include_path() . PATH_SEPARATOR . 'phpseclib');
body: <p>I have stumbled upon two functions i have never used before in php</p>
  
  <pre><code>set_include_path();
  get_include_path();
  </code></pre>
  
  <p>I am currently looking to implement the phpseclib onto a project I am working on.. As i need to use the SFTP class extension of the SSH2 which in turn requires the MathBigInteger class.. etc etc.</p>
  
  <p>The manual says about <code>set_include_path()</code>:</p>
  
  <blockquote>
    <p>"Sets the include_path configuration option for the duration of the
    script. "</p>
  </blockquote>
  
  <p>What does this mean for the rest of my framework, will it set ALL include paths from the 'phpseclib' dir?</p>
  
  <p>Also, I really don't get:</p>
  
  <pre><code>set_include_path(get_include_path() . PATH_SEPARATOR . 'phpseclib');
  </code></pre>
  
  <p>I am storing the php sec in a custom library directory in my file system, does get_include_path() some how magically find the phpseclib directory in my filesystem?</p>
  
  <p>As you can see I am completely lost here.. could anyone be kind enough to shed some light for me please?</p>
  
  <p>PS/
  I only need this library at one partivular point in the application thus only want to include it when needed, at present I am wanting to include it within a child of my model class.</p>