Get apache linux user from php

Question

I'm on a foreign linux system and need to determine the user that apache runs on (and so does php).

The aim: I need to get the owner of the script (this is no problem as I can use SplFileInfo) and compare it to the owner of the apache process.

I'm open to any alternative proposals.

Regards, Mario

Edit: Additional info:

The script is a thumbnail generator, that uses an XML file to generate thumbs from larger images. The script needs to create folders and write files. As I cannot influence the php configuration and I do not have any shell access, this has to be done very silently. The creation process stopps via exception and sends a mail on failue. As most of php's function cannot throw exceptions on failue, I need some manual checks to determine the environment I'm in. Therefore I need the apache user to compare it to some directory or fileowner.

Answer 1

You can call the php exec function to execute whoami:

<?php echo exec('whoami'); ?> 

Answer 2

see posix_getuid() and posix_getpwuid()