This topic documents intended Programming Interfaces that allow you to write programs to obtain the services of DFSMS. This topic is intended to help you to write ACS routines.

ACS routines determine SMS classes and storage groups for all new data set allocations and for data set allocations that occur from converting, copying, recalling, restoring or moving data sets. For objects, ACS routines determine: storage group, when storing them; or storage class and management class, when storing or changing them, or during class transitions. You write ACS routines in the ACS language, which is a high-level programming language. You can write your ACS routines, one for each type of SMS class and one for your storage groups.

After writing the routines, you must translate them into an object form that SMS understands. A successful translation places the ACS object in a specified SCDS. After you activate the configuration contained in that SCDS, ACS routines govern storage management.

When you enter the ISMF Automatic Class Selection Application and select the EDIT option, you are linked to PDF Edit, where you can create or modify ACS routines. Leaving EDIT returns you to the ISMF Automatic Class Selection Application, where you can translate, validate, or test any ACS routine.

This topic contains four main sections. The first section describes the ACS language constants. The second section describes read-write variables. The third section describes read-only variables, which the ACS routines use for comparison operations. The fourth section describes the ACS language statements and illustrates the use of the statements in a storage group selection routine.