Library List in AS400

Library List: 

• A library list is a list of libraries maintained for each user session with the libraries arranged in decreasing order of priority.

• Whenever an object is referenced in command without a library, then the system starts checking for the object in all the libraries in the library list.

• If the object is found in the first library, then the system picks that object from that first library.

• If the object is not found in any library in the library list then the system will throw an error.

For Example:

• Assume the program PGM01 is in the 3 libraries.

• PGMLIB1 -- PGM01

• PGMLIB2 -- PGM01

• PGMLIB3 -- PGM01

• If we execute CALL PGM01 in the command line, then the system will pick up the program PGM01 from the PGMLIB1 library as that has the top priority in the library list among the 3 libraries.

• In case, if we execute a command like this CALL PGMLIB2/PGM01, then the system will pick it from the PGMLIB2 library that is explicitly mentioned.

Also to Note:

• Any change that is done to the library list is private to that session. The default library list for a user can only be set by the Admin.

• AS/400 Libraries follows a single-level hierarchy, which means no library other than the root library contains other libraries within it.