Need to Bulletproof this PHP include. Getting Failed to Open Stream
<p>I've got some functions in my file that require taxonomy.php to execute. I'm attempting to include the file like so...(this is called from functions.php, which is located in wp_content/themes/mytheme/</p>

<pre><code>include($_SERVER['DOCUMENT_ROOT'] .'/wp-admin/includes/taxonomy.php');
</code></pre>

<p>However, depending on the particular server setup, its hit or miss (mostly hit) whether the include will be found. In the case its not found, I get this error...</p>

<p>Warning: include(/home/user/domainname.com/wp-admin/includes/taxonomy.php) [function.include]: failed to open stream: No such file or directory in /home/user/domainname.com/testing123/wp-content/themes/mytheme/functions.php on line 10</p>

<p><strong>*UPDATE: Assuming I'm already doing about as much as I can by using DOCUMENT_ROOT, is there a means of avoiding the error that occurs when the file is not found? And I will be checking for function_exists in any functions that require taxonomy.php so as to suppress errors...*</strong></p>
