Enumerate - Listing items

Enhanced Definition

In the context of z/OS, "enumerate" refers to the act of systematically listing, detailing, or cataloging items, resources, or conditions within the mainframe environment. While not a specific command or technology itself, it describes a fundamental operation crucial for system management, development, and auditing. It involves retrieving and presenting a collection of related entities for review or further processing.

Key Characteristics

- Systematic Retrieval: Involves querying system components, catalogs, or libraries to retrieve a collection of related items based on specified criteria.
- Diverse Scope: Can apply to various entities such as datasets, members within partitioned datasets, active jobs, system tasks, security profiles, storage volumes, or even specific system parameters.
- Output-Oriented: The result is typically a structured list, report, or log that can be displayed interactively (e.g., on a TSO screen), printed, or stored in a dataset for further programmatic analysis.
- Tool-Dependent: The specific method of enumeration depends on the type of item and the tool used, ranging from interactive ISPF panels to batch utilities, system commands, and programming interfaces.
- Informational Purpose: Primarily used to gain insight into the current state, inventory, configuration, or operational status of mainframe resources and processes.

Use Cases

- Dataset Management: Listing all datasets on a specific volume or matching a particular high-level qualifier using IDCAMS LISTCAT or ISPF 3.4 to manage storage, identify unused space, or locate specific files.
- Program Library Analysis: Enumerating members within a PDS or PDSE (e.g., a COBOL source library, load library, or JCL procedure library) to