COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

library-reference
is a mnemonic-name in the SPECIAL-NAMES paragraph. This mnemonic-name is associated
with the DLL containing an object copy of COBOL_CONTROL_.
file-name
is a COBOL file name associated with a file that is not $RECEIVE and that is not open for
HP COBOL Fast I-O. If the file is not open, the call to the Guardian environment routine
CONTROL is made during the next successful open request for the file.
operation
is a numeric data item or arithmetic expression that is the operation parameter of the
Guardian environment routine CONTROL. For more information, see the Guardian Procedure
Calls Reference Manual.
param
is a numeric data item or arithmetic expression that is the param parameter of the Guardian
environment routine CONTROL. For more information, see the Guardian Procedure Calls
Reference Manual.
cpinfo
is a checkpoint list in which the routine records the changes to the message storage data space,
for example:
01 CP-LIST-1.
05 MAX-COUNT PIC 9999 COMP VALUE IS 100.
05 CURRENT-COUNT PIC 9999 COMP VALUE IS 0.
05 ELEMENT PIC 9(9) COMP OCCURS 100 TIMES.
The initial value of MAX-COUNT must be the same as the number of occurrences of ELEMENT.
The maximum number of elements that cpinfo can contain is the initial value of MAX-COUNT
divided by 2.5. The cpinfo in the preceding example can contain 40 elements.
The required number of table elements depends on the number of operations the list must
record. The worst-case situation uses six elements.
A complete checkpoint list is required only when a program has a backup that must be kept
current. When a record of changes is not required, a null checkpoint list can be used. This is
an example description:
03 CP-LIST-1 PIC 9(9) COMP VALUE IS 0.
error-return
is a numeric data item that has one of these values upon completion:
MeaningValue
The call to CONTROL caused Guardian file error n.n
No error occurred.0*
A required parameter is missing.1
file-name is not a COBOL file name.2
One of:5
• file-name specifies an open file that is either $RECEIVE or is open for Fast I-O.
• file-name specifies a closed file and there is not enough control space to allocate the
queued information for the next open request.
*error-return is 0 for a deferred call (that is, one that is held until the file is open). If an error occurs at that
time, a run-time diagnostic is issued.
ZCOBDLL Routines 617