Php having access to the filesystem - getting Permission Denied

Question

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)

Thanks

Answer 1

The first two thing I would check:

• What user is PHP running under? If it's spawned by Apache, it is likely running as "nobody", "www" or "apache" depending on the version and configuration.

• What directory are you trying to list? Check the permissions on that directory. Does the user PHP is running as have permission to access that directory?