ABCs of z/OS System Programming Volume 3 - IBM Redbooks

4.14 Access method services (IDCAMS)
Access method services is a utility to:
Define VSAM data sets
Maintain catalogs
Command interface to manage VSAM and catalogs
Functional commands
Modal commands
Invoke IDCAMS utility program
Using JCL jobs
From a TSO session
From a user program
Figure 4-20 Access method services
Access method services
You can use the access method services utility (also know as IDCAMS) to establish and
maintain catalogs and data sets (VSAM and non-VSAM). It is used mainly to create and
manipulate VSAM data sets. IDCAMS has other functions (such as catalog updates), but it is
most closely associated with the use of VSAM.
Access method services commands
There are two types of access method services commands:
Functional commands Used to request the actual work (for example, defining a data set or
listing a catalog)
Modal commands Allow the conditional execution of functional commands (to make it
look like a language)
All access method services commands have the following general structure:
COMMAND parameters ... [terminator]
The command defines the type of service requested; the parameters further describe the
service requested; the terminator indicates the end of the command statement.
Time Sharing Option (TSO) users can use functional commands only. For more information
about modal commands, refer to z/OS DFSMS Access Method Services for Catalogs,
SC26-7394.
Chapter 4. Storage management software 129