MPE/iX Intrinsics Reference Manual (32650-90875)

382 Chapter7
Command Definitions (HP32208-HPLOACNMPROC)
HPFOPEN
nonshareable device should be ready prior to the HPFOPEN call (otherwise,
an error results).
Only one of the following options can be in effect when a file is opened:
itemnum =20
itemnum =22
itemnum =23
itemnum =42
Default: Disk file located on the volume class DISC associated with the
group in which file resides.
A character placed in the first element designates the delimiter used by
HPFOPEN to search for the end of the character array. The delimiter can
appear again only following the last valid character of the character array,
for example:
%devname% (% is the delimiter, devname is the designator)
fabcxyzf ( f is the delimiter, abcxyz is the designator)
21/@64 Long-mapped:
Returns a long-pointer to the beginning of data of the file. This option
maps the file into long pointer space. A long-mapped file can be up to 4GB
-64KB or (4,294,901,760 bytes) in size. There is no limit to the number of
long-mapped files a process can have open at one time. The pointer can be
used as a large array of any type to access the file.
A loaded program file or a loaded library file is not accessible, and a file
cannot be loaded with this option.
Sharing long-pointer files is provided through normal file system file
sharing mechanisms. All file system intrinsics applicable to the file can be
used. FREAD and FWRITE calls can be mixed with this option.
Standard (STD) disk files of fixed or undefined record length can be
accessed with this option. Standard disk files of variable record length can
be accessed only if
itemnum =11 (read-only access). Standard disk files of
variable record length and KSAM files can be accessed only if
itemnum =11
(read-only access) and
itemnum =17 (set to 1).
Directories may not be opened using long-mapped access.
Default: Not returned
(ASC) Not used for asynchronous devices.
22/CA Volume class:
Passes a character array representing a volume class name where the file
space is to be restricted. This option is applicable only at file creation.
A volume class is a subset of volumes within a volume set. The volume
class name must be a valid volume class name residing on the volume set