title: Make php variable/constant available to all scripts ad all sites
body: <p>I have about 150 websites each on its own Apache virtual host running php7 on ubuntu 16. Each site has a config.php in the root dir with constants in it: define('MYVAR','myval');</p>
  
  <p>I want to make a new constant that I will have to update every 2 months or so. I don't want to open each config and edit them. How can I have each site/virtual host be aware of this constant I want to set. I want to be available everywhere just like $_SERVER['REMOTE_ADDRESS']; is.</p>
  
  <p>I do not want to create a file them symlink it to each site, thats messy. I would like to edit the apache config or edit a php config someplace to have a define() in it.</p>
  
  <p>Is this possibe? or am I stuck sym linking a file or editing all my configs? </p>