Data Set Names and Metadata

z/OS provides application programming interfaces (APIs), utility, and service aids programs so that you can access the names of data sets and their metadata. Metadata is information about data.

The APIs that access data set names include the following:

OBTAIN macro: Reads one or more data set control blocks (DSCBs) from a VTOC.
CVAF macros: Reads a VTOC and VTOC index. These macros are CVAFDIR, CVAFDSM, CVAFFILT, CVAFSEQ, and CVAFTST.
RDJFCB macro: You can use the RDJFCB macro to learn the name of a data set and the volume serial number of a VSAM data set. You also can use RDJFCB with the OPEN TYPE=J macro to read a VTOC. When you use the RDJFCB macro, use a DCB and the exit list for the DCB because using an ACB and VSAM exit list would not work.
OPEN TYPE=J macro: Can be used to open and read a VTOC. This macro supplies a job file control block (JFCB), which represents the information in the DD statement. VSAM does not support OPEN TYPE=J.
LOCATE macro: Locates and extracts information from catalogs.
Catalog search interface: Locates and extracts information from catalogs. For more information, see z/OS DFSMS Managing Catalogs.

Related reading: For more information on these macros, see z/OS DFSMSdfp Advanced Services.

The utility and service aid programs include:

ISPF: A full-screen editor and dialog manager, it generates standard screen panels and interactive dialogues between the application programmer and terminal user. For more information, see z/OS ISPF User's Guide Vol I.
ISMF: Is the interactive interface of DFSMS that allows you to access the storage management functions. For more information, see z/OS DFSMS Using the Interactive Storage Management Facility.
IEHLIST utility: Lists entries in the directory of a PDS or PDSE, or entries in a non-indexed or indexed VTOC. For more information, see z/OS DFSMSdfp Utilities.
SPZAP service aid: Edits data sets on a DASD. You also can use SPZAP to apply fixes to programs to bring them up to the current level of the operating system. Because SPZAP can alter data sets, use Resource Access Control Facility (RACF®) or an equivalent security product to protect those data sets that you do not want changed. (RACF is a component of the z/OS Security Server.) For more information, see z/OS MVS Diagnosis: Tools and Service Aids.