IMS catalog API (DFS3CATQ)
You can find information about using the IMS catalog API to request information about runtime application control blocks and program specification blocks from the IMS catalog.
Accessing the DFS3CATQ API
The DFS3CATQ API is provided with IMS in the DFS3CATQ assembler language macro.
Programming requirements
The DFS3CATQ API macro can be invoked from AMODE 24 or 64 callers. The invoking module can reside
anywhere below the 2 GB bar.
Note: RMODE(64) is not supported.
The program that invokes the DFS3CATQ macro must be in task mode and not in cross-memory mode. The calling module need not reside in an APF-authorized library.
Execution environment
Programs that access the DFS3CATQ API can execute in an address space outside of IMS, and the IMS system need not be in the running state. If called from outside of IMS, an IMS RESLIB must be available in the standard z/OS search order of load modules.
Register usage
Input register information:
- Before invoking the DFS3CATQ macro, GPR 13 must point to a standard 18-word save area.
Output register information:
- R0
- Reason code
- R1
- Used as a work register
- R2 - R13
- Unchanged
- R14
- Used as a work register
- R15
- Return code