Does PHP's get_defined_functions() show available functions or functions being used?
<p>I just discovered the get_defined_functions() function in PHP, I was checking it out, it list all the functions.  </p>

<p>It in addition to php's built in functions, it list 176 function I have made for my site.</p>

<p>I have a question about it, are all the listed functions from this being loaded, like taking up resources or is it just showing they are available if I need them?  </p>

<p>If it just shows all functions available, is there a way to list all that are being used?</p>

<pre><code>print_r(get_defined_functions());
</code></pre>
