When you submit a batch job to Enterprise Server, job information is written to the casspool.dat file, which is continually updated throughout the life of the job. This creates a chronological record of the stages of execution from the job submission stage through to job completion.
While the ESMAC spool queues interface enables you to view the status of current jobs in Enterprise Server, it does not provide full access to the information held in the spool files. The CASSPOOL API does provide full access. When you call it from a COBOL program, you can retrieve all or some of the data held in the spool files by referencing one or more keyed indexes.