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HP COBOL
Reference Manual
4.2.7 PADDING CHARACTER
Function
The PADDING CHARACTER clause specifies the character to be used to pad
blocks in sequential files.
pad-char
is a one-character nonnumeric literal or the data-name of a
one-character data item. The data-name can be qualified.
General Rule
The PADDING CHARACTER clause is for documentation only.
4.2.8 RECORD DELIMITER (OpenVMS)
Function
The RECORD DELIMITER clause indicates the method of determining the
length of a variable record on the external medium. It is for
documentation only.
General Rule
On OpenVMS, STANDARD-1 is the I/O system (OpenVMS Record Management
System [RMS]) default for tape files. It is the method used for
determining the length of a variable-length record. This method is
specified in the American National Standard X3.27-1978,
"Magnetic Tape Labels and File Structure for Information
Interchange," and International Standard 1001 1979,
"Magnetic Tape Labels and File Structure for Information
Interchange."
Additional Reference
For OpenVMS systems, refer to the OpenVMS Record Management Services Reference Manual for more
information. <>
4.2.9 RESERVE
Function
On OpenVMS systems, the RESERVE clause specifies the number of
input-output buffers for a file. <>
On Tru64 UNIX systems, RESERVE is for documentation purposes only.
<>
reserve-num
is an integer literal from 1 to 127. It specifies the number of
input-output areas for the file.
General Rule
On OpenVMS systems, if there is no RESERVE clause, the number of
input-output areas equals the I/O system default.
Technical Note
For OpenVMS systems, two DCL commands change and display the defaults
for block count: SET RMS DEFAULT and SHOW RMS DEFAULT. The number of
areas is stored in the MBF field of the RAB.
Additional References
Refer to the RMS documentation for field RAB$B_MBF. <>
4.2.10 I-O-CONTROL
Function
The I-O-CONTROL paragraph specifies the input-output
techniques to use for a file.
On Tru64 UNIX systems, a number of the elements in the I-O-CONTROL
paragraph are for documentation only. See the Technical Notes for more
information. <>
extend-amt
is an integer from 0 to 65,535. It specifies the number of blocks in
each extension of a disk file.
file-name
is the internal name of a file connector.
Each file-name must have a file description (or Sort-Merge
File Description) entry in the Data Division. The same
file-name cannot appear more than once in the FILE-CONTROL
paragraph.
preall-amt
is an integer from 0 to 4,294,967,295. It specifies the number of
blocks to initially allocate when the program creates a disk file.
window-ptrs
is an integer from 0 to 127. Its value can also be 255. It specifies
the number of retrieval pointers in the window that maps the disk file.
same-area-file
names a file described in a Data Division file description entry to
share storage areas with every other same-area-file.
rec-count
is an integer specifying the number of records to process before
writing the rerun information.
clock-count
is an integer specifying an interval of time to elapse before writing
the rerun information.
condition-name
names a switch status which, when set, causes the rerun information to
be written. The switch is defined in the Section 4.1.3 paragraph of
Section 4.1, CONFIGURATION Section.
multiple-file
is a file described in a Data Division file description. It specifies
that the file shares storage on a reel/unit device with other files. No
more than 255 files can be specified.
pos-integer
is an integer from 1 to 255. It specifies the relative location of a
file on a tape that contains multiple files.
Syntax Rules
- The I-O-CONTROL clauses can appear in any order.
- As the following table shows, each phrase of the APPLY clause can
refer only to some file types.
| Phrase |
File Type |
|
EXTENSION
|
Disk file
|
|
FILL-SIZE
|
Indexed organization
|
|
LOCK-HOLDING
|
Disk file
|
|
MASS-INSERT
|
Indexed organization
|
|
PREALLOCATION
|
Disk file
|
|
PRINT-CONTROL
|
Sequential organization
|
|
WINDOW
|
Disk file
|
- More than one APPLY clause can refer to the same file-name.
- The phrases of the APPLY clause can appear in any order. However,
each phrase can be used only once for each file-name.
- You can specify the LOCK-HOLDING phrase only if you specify the
ALLOWING option of the OPEN statement.
- The RERUN and MULTIPLE FILE clauses cannot refer to a sort or merge
file.
- In the SAME AREA clause, SORT and SORT-MERGE are equivalent.
- If same-area-file refers to a sort or merge file, you must
use the SORT, SORT-MERGE, or RECORD phrase.
- A program can contain more than one SAME clause. However, the
following conditions apply:
- A same-area-file cannot be in more than one SAME RECORD
AREA clause.
- A same-area-file that refers to a sort or merge file
cannot be in more than one SAME SORT AREA or SAME SORT-MERGE AREA
clause.
same-area-files cannot have the global or the
external attribute if the program specifies the SAME RECORD AREA phrase.
- Files specified in a MULTIPLE FILE TAPE clause must be sequential.
- A file cannot be specified in more than one MULTIPLE FILE TAPE
clause.
General Rules
APPLY Clause
- An APPLY clause remains active for a file-name until the
image terminates.
- If the file connector referenced by file-name is an
external file connector, all file control entries in the run unit that
reference this file must have the same APPLY clause.
- The DEFERRED-WRITE phrase causes a physical write operation to
occur only
when the input-output buffer for file-name is full. If there
is no DEFERRED-WRITE phrase, a physical write occurs each time an
output statement executes for file-name.
- The EXTENSION phrase specifies the number of disk blocks to be
added each
time a file is extended. The I/O system extends a file when it needs
more file space to add a record.
If extend-amt equals
zero, the I/O system extends the file by its default value.
- The FILL-SIZE phrase causes the I/O system to use the fill size
specified when an
indexed file is created to fill the file's buckets. If there is no
FILL-SIZE phrase, the I/O system fills buckets completely. The
FILL-SIZE phrase applies only to indexed files.
- The LOCK-HOLDING phrase declares the Hewlett-Packard standard
manual record-locking attribute for a
sequential, relative, or indexed file in a file-sharing environment on
disk.
Once a record is manually locked (see the Section 6.8.26,
Section 6.8.30, Section 6.8.34, and Section 6.8.43 statements in
Chapter 6, Procedure Division), it remains locked until one of the following occurs:
- An UNLOCK statement executes.
- A CLOSE statement executes for the subject file.
- The image terminates.
Usage of the APPLY LOCK-HOLDING option requires additional syntax
for the OPEN, READ, REWRITE, START, and WRITE verbs. Table 4-2
summarizes the additional syntax required for Procedure Division I/O
statements accessing a file possessing the manual record-locking
attribute.
- X/Open standard and Hewlett-Packard standard syntax cannot both be
specified for the same file connector. Hence, APPLY LOCK-HOLDING cannot
be specified if LOCK MODE was specified for that file in the SELECT
statement.
Legend:
X---Required
N/A---Not Applicable
*---If the ALLOWING option is not specified
- The MASS-INSERT phrase is for documentation only. It has no effect
on
program execution.
- On OpenVMS the PREALLOCATION phrase causes the I/O system to
allocate preall-amt
disk blocks when it creates the file.
- The CONTIGUOUS phrase specifies that the preallocated disk blocks
must be contiguous. If the I/O system cannot find preall-amt
contiguous disk blocks, the OPEN operation fails.
- The CONTIGUOUS-BEST-TRY phrase causes the I/O system to try to
preallocate disk blocks contiguously. If the I/O system cannot find
preall-amt contiguous disk blocks, it preallocates disk blocks
in the largest possible contiguous areas.
- The PRINT-CONTROL phrase specifies that the file has print file
format.
Additionally, the PRINT-CONTROL phrase applies only to sequentially
organized files.
The PRINT-CONTROL phrase is redundant if:
- The file description entry contains a LINAGE clause
- The program contains a WRITE statement with the ADVANCING phrase
for the file
- The Report Writer Control System is in effect
- The WINDOW phrase causes the I/O system to use window-ptrs
number of
retrieval pointers in mapping the files. window-ptrs must fall
in the range of 0 to 127 inclusive or be equal to 255. If
window-ptrs is 255, then the I/O system attempts to map the
entire file. <>
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