Control Statements - IBM 3741 Data Station Reference Manual

D-----R-----B7 --·-B8----A .... B9----A .... E
/\~
This field in
I
his field in This field in
the program the program the program
indicates that indicates that
indicates that
field totals field totals field totals
accumulator 1 accumulator 2 accumulator 3
will be read
will be read will be read
out into the out into the out into the
corresponding corresponding corresponding
field in the field in the field in the
data record data record data record
and then and then
and then
accumulator 1 accumulator 2 accumulator 3
wi II be reset wi II be reset
will be reset
to zero. to zero. to zero.
Figure 22. Example of a Read Out/Reset Field in a Program
Not all of the accumulators have to be read out and reset
when performing a field totals read out/reset operation.
You can select accumulators to be read out and reset. If
desired, each accumulator can be read out and reset at a
different point during a field totals operation.
CONTROL STATEMENTS
Offline field totals require a control statement as part of
the field totals operation. A control statement, when
satisfied, causes a particular program to be selected for
processing the record. A control statement:
• Must start with a
<
character (this is the only means
by which the field totals program can identify a control
statement) .
• Maybe continued in a consecutive or higher numbered
buffer.
42
• Identifies which positions in the current record are to
be compared against the compare characters.
• Identifies what character must be at a position being
compared, what character should not be at a position
being compared, or some combination of both condi-
tions in order for the control statement to be satisfied.
• Must not be loaded into any program buffer that will
be selected when a control statement is satisfied.
• Identifies the program to use when the control state-
ment is satisfied. The selected program identifies:
The fields in the current record that are to be
accumulated and into which accumulator the contents
of each field must be accumulated.
The fields in the current record that an accumulated
value will be read into (if indicated by the program).
The fields in the current record that an accumulated
value will be read into and then the accumulator re-
set to zero (if indicated by the program).
Figure 23 identifies the control statement format characters.