When attempting to chmod a directory, I recieve this warning.
Warning: chmod() [function.chmod]: Operation not permitted in /xxx/validation.php on line 603
The directory permissions are not changed, but I am able to move my files, etc.
What does this mean?
This likely indicates that the web server does not have permission to do the chmod. Only the owner of the file or directory (or a superuser) can perform the chmod action. If the owner of the web server process is not the owner of the file or directory, then chmod will fail.
Not sure which user the web server is running under? Try this:
echo system('whoami');
Or for Windows:
echo get_current_user();