This is a secure method to debug your apache from within php

For debugging without checking error_log/access_log files

1. create a file called phpinfo.php in your / directory

2. the contents of phpinfo.php

3. Use this for your .htaccess file.

   Options +FollowSymLinks
   ErrorDocument 404 /phpinfo.php
   

Now instead of getting a 404 error you will see debug information which will help you find out what the problem is.

Add security to phpinfo.php

Cd-MaN pointed out a security problem this method has, it reveals sensitive info to anyone who requests phpinfo.php.

Also, you better use it only as a temporary measure, because it reveals many sensitive information about your server (eg. delete it after you done debugging)

Here is a fix for this.

Secure phpinfo.php with .htaccess

This only allows the user from IP address 2.3.65.6, everyone else is redirected to http://www.domain.com

ErrorDocument 403 http://www.domain.com
Order deny,allow
Deny from all
Allow from 2.3.65.6

Secure phpinfo.php with php

Same thing only uses .htaccess. Change your phpinfo.php file to the following