CA Compress/2 › The CA Compress/2 Utilities

The CA Compress/2 Utilities

Unlike the subroutines, the utilities offer no capabilities beyond those supplied through the CA Compress Transparency or SUBSYS implementations. All utility functions are supported more effectively by the subsystem and the Interactive User Interface, and so the utilities are seldom called for. The utilities supply the following functions:

• Prepass performs test compression, like the Interactive User Interface, and creates a sequential FDT.
• The FDTLOADR utility converts a sequential FDT to load module format. The Interactive User Interface executes this utility automatically because the Transparency and SUBSYS implementations do not support sequential FDTs.
• Two compression utilities are supplied to support Hardware Compression and custom compression using FDTs generated either by the Prepass function or by the Interactive User Interface. No utility support is provided for compression using Standard Tables and Super Express.
• Three expansion utilities are provided to support both custom and noncustom methods, including Hardware Compression—EXPAND and EXPANDX, and SHRHCXPD. These enable disaster recovery in the event that no subsystem is available. Minor differences between the utilities and the subsystem require care when expanding data compressed by the subsystem.

The CA Compress/2 utilities are not reentrant and cannot reside in the Link Pack Area. JCL to execute these utilities is provided in the distribution JCL, file number 1 on the release tape.