title: Apache + mod_php how to manually log error?
body: <p>I have Apache 2.4 and php 5.6 as a module.
  Is there any way to send custom error to current 'ErrorLog' file? 
  'ErrorLog' directive depends on time (daily logs). 
  And I have very specific requirements:</p>
  
  <ul>
  <li>I cant call <code>trigger_error</code> function (error message should not be displayed, only logged);</li>
  <li>I cant use <code>display_errors</code> with <code>none</code> value</li>
  <li>I cant use @ operator</li>
  </ul>
  
  <p>Any variants?</p>