Recommendations for the user portion of the library list
In this topic you will find the recommendations for controlling the user portion of the library list.
The user portion of the library list often changes more than the other portions and is more difficult to control. Many application programs change the library list. Job descriptions also affect the library list for a job.
Here are some suggested alternatives for controlling the user portion of the library list to make sure that unauthorized libraries with substitute programs and files are not used during processing:
- Restrict users of production applications to a menu environment. Set the Limit capabilities field in user profiles to *YES to restrict their ability to enter commands. Planning menus provides an example of this environment.
- Use qualified names (object and library) in your applications. This prevents the system from searching the library list to find an object.
- Control the ability to change job descriptions, because the job description sets the initial library list for a job.
- Use the Add Library List Entry (ADDLIBLE)
command at the beginning of the program to ensure the required objects are
at the beginning of the user portion of the library list. At the end of the
program, the library can be removed.
If the library is already on the library list, but you are not sure if it is at the beginning of the list, you must remove the library and add it. If the sequence of the library list is important to other applications on the system, use the next method instead.
- Use a program that retrieves and saves the library list for a job. Replace the library list with the list required for the application. When the application ends, return the library list to its original setting. See Controlling the user library list for an example of this technique.