Open System Services System Calls Reference Manual (G06.28+, H06.05+)

SPT_FILE_OPEN_(2) OSS System Calls Reference Manual
its structured form. (HP reserves the right to change this block
format at any time.) For information about Enscribe block for-
mats, see the Enscribe Programmer’s Guide.
For a file opened using the unstructured access option, a data
transfer occurs to the position in the file specified by an RBA
(instead of to the position indicated by a key address field or
record number); the number of bytes transferred is that specified
in the file-system procedure call (instead of the number of bytes
indicated by the record format).
If a partitioned file, either structured or unstructured, is opened
using the unstructured access option, only the first partition is
opened. You must open the remaining partitions individually
with separate calls to SPT_FILE_OPEN_() (each call specify-
ing unstructured access).
Accessing audited structured files as unstructured files is not
allowed.
Current-state indicators after an open
After successful completion of an open, the current-state indicators have these
values:
• The current position is that of the first record in the file by primary key.
• The positioning mode is approximate.
• The comparison length is 0.
If the Guardian READ procedure is called immediately after
SPT_FILE_OPEN_() for a structured file, READ reads the first record in the
file; in a key-sequenced file, this is the first record by primary key. Subsequent
reads, without intervening positioning, read the file sequentially (in a relative or
entry-sequenced file) or by primary key (in a key-sequenced file) through the last
record in the file. When a key-sequenced file is opened, the Guardian KEYPO-
SITION procedure is usually called before any subsequent Guardian I/O pro-
cedure call (such as READ, READUPDATE, or WRITE) to establish a position
in the file.
Queue files If the READUPDATELOCK operation is to be used, the value of the
sync_or_receive_depth parameter must be 0 (zero). You can use a separate open
for operations with sync_or_receive_depth greater than 0 (zero).
You cannot use sequential block buffering.
64-bit primary keys
In order to access non-key-sequenced files bigger than 4 gigabytes, you must set
bit 31 of the SPT_FILE_OPEN_() elections parameter. Use of this parameter
allows the use of procedures using 32-bit primary keys (POSITION, KEYPOSI-
TION, REPOSITION, GETSYNCINFO, and SETSYNCINFO) and the 32-bit
key items of the FILE_GETINFOLIST_, FILEINFO, and FILERECINFO pro-
cedures.
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