Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (F)
Guardian Procedure Calls Reference Manual—522629-013
5-54
FILE_CREATELIST_ Procedure
Considerations
•
Using item-list
In general, if you supply an item in
item-list that is not applicable (for example,
if you supply a logical record length for an unstructured file), FILE_CREATELIST_
ignores the item as long as it passes syntax and value range checks. Exceptions
to this are noted in Table 5-3
.
•
File pointer action
The end-of-file pointer is set to 0 after the file is created.
•
Disk allocation with FILE_CREATELIST_
Execution of the FILE_CREATELIST_ procedure does not allocate any disk area; it
only provides an entry in the volume’s directory, indicating that the file exists.
•
Altering file security
The file is created with the caller’s process file security which can be examined and
set with the PROCESSFILESECURITY procedure. Once a file has been created,
its file security can be altered by opening the file and issuing the appropriate
SETMODE and SETMODENOWAIT procedure calls.
•
Odd unstructured files
An odd unstructured file permits reading and writing of odd byte counts and
positioning to odd byte addresses.
If item 65 is set to 1 and item 42 is set to 0 in
item-list, an odd unstructured file
is created. In that case, the values of
record-specifier, read-count, and
write-count are all interpreted exactly; for example, a write-count or read-
count of 7 transfers exactly 7 bytes.
•
Even unstructured files
If items 65 and 42 are both set to 0 in
item-list, an even unstructured file is
created. In that case, the values of
read-count and write-count are each
rounded up to an even number; for example, a
write-count or read-count of
7 is rounded up to 8, and 8 bytes are transferred.
An even unstructured file must be positioned to an even byte address; otherwise,
the FILE_GETINFO_ procedure returns error 23 (bad address).
If you use the File Utlity Program (FUP) CREATE or HP Tandem Advanced
Command Language (TACL) CREATE command to create a file, it creates an even
unstructured file by default.
•
Upper limit for maximum extents
If you specify a value greater than 500 for maximum extents (item 52 in
item-
list), there is no guarantee that a file will be created successfully. In addition,
FILE_CREATELIST_ returns error 21 if the values for primary and secondary