File Management - IBM

name displayed (at the top of the list) on the call stack is the program at call level
1 for that job. Call level 1 is the lowest call level for a job. The second program
name displayed is the program at call level 2 for that job. The last program name
displayed is the program at the highest call level for that job.
In the example in Figure 5 on page 42, the Transfer Control (TFRCTL) command to
PGMC causes PGMC to replace PGMB from the call stack. A CALL command
places another program in the call stack. A RETURN command removes a program
from the stack.
Processing priority of overrides
The system processes overrides when an open operation occurs in the following
order:
1. Call level overrides up to and including the level of the oldest procedure in the
activation group are applied first.
2. Activation group level overrides that were specified within the same activation
group that the open operation was issued are applied.
3. Call level overrides below the level of the oldest procedure in the activation
group are applied.
4. Job level overrides are applied.
How the system processes overrides-scenario 1
The following shows an example of how overrides work in multiple activation
groups:
Chapter 3. Using overrides 43