I'm trying to track down a php issue with a tool that I'm trying to install, and have tracked it down, I believe, to a permissions issue with the filesystem, I believe...
I now have the following simple .php file:
<?php system("/bin/ls"); ?>
When I run this, I see the following error in /var/log/httpd/error_log:
sh: /bin/ls: Permission denied
If I change the php to run:
<?php system("/bin/env"); ?>
Then I see the output that I was expecting.
So it's not the execution that doesn't have permissions, it's what the executable is trying to read that is having problems.
(The tool I am trying to get working here is phplicensewatcher - a tool for keeping an eye on what is going on with various license management daemons)