KDE is an extensively configurable desktop environment. In addition to being configurable for the individual user, it is also configurable for administrators. This allows system administrators to provide custom default settings for their environments. Settings can differ between groups and individual users. It is also possible to restrict which settings users can change. Additionally, access to parts of KDE or functions in KDE can be restricted for all users, groups of users, or specific users.
KDE reads and stores all files in fixed directory trees. Several directories can be used to store system or group-specific configuration. One directory tree with user data is saved in each user’s home directory.
KDE and all KDE applications scan these directory trees in a preset order. Normally, the home directory tree is scanned first, giving it a higher priority. In most cases, the application uses the first file found. For configuration files, all files in all directory trees with the same name are read and the content merged. The priority order is used to handle different configurations for the same configuration key.
The directory locations can be changed using the following environment variables:
Table F-1 Directory Location Environment Variables
Each directory tree used by KDE has a fixed directory structure. However, directories not relevant for a certain tree need not be included. For example, directories used for temporary files are usually found in $KDEHOME but not in any other directory tree.
The KDE runtime environment combines the subdirectories found in the various directory trees and refers to them as a single KDE resource. There are three broad categories: files that are CPU or architecture-specific, files that are host-specific, and files that are not specific with regard to host, CPU, or architecture. You can view a list of resources at the KDE for System Administrators Filesystem Hierarchy Web site.