MPE/iX Intrinsics Reference Manual (32650-90905)
Chapter 7 383
Command Definitions (HP32208-HPLOACNMPROC)
HPFOPEN
short-mapped option. A file cannot be loaded that is currently opened with
the short-mapped option.
Sharing of short pointer files is provided through normal file system
sharing mechanisms, for example, use of the exclusive option. With the
short-mapped file, all file system intrinsics, applicable to the file, can be
used. FREAD and FWRITE calls can be mixed with the short-mapped access.
Standard (STD) type disk files of fixed or undefined record length can be
accessed short-mapped with the access type option set to any value.
Standard type disk files of variable record length can be accessed
short-mapped only if the access type option is set to read-only access.
KSAM files can be accessed short-mapped only if the access type option is
set to read-only access and the copy mode option is set to 1.
Directories may not be opened using short-mapped access.
Default: No short pointer returned
(ASC) Not used for asynchronous devices.
19/I32 Record size:
Passes the size, in bytes, of the logical records in the file. Valid range is
dependent upon both storage format (ASCII or binary) and record format.
For fixed-length and undefined-length ASCII files, a record size can be
specified in the range 1..32,767. For variable-length ASCII files, and for
fixed-length, variable-length, and undefined-length binary files, a record
size can be specified in the range 1..32,766.
HPFOPEN rounds up odd values to the next highest even number
(equivalent to the nearest half word boundary) if the file is ASCII with
variable-length record format, binary with fixed-length, variable-length, or
undefined-length record format.
For example, if a record size of 105 is specified for a fixed-length binary
file, HPFOPEN sets the record size to 106; if a record size of 233 is specified
for a fixed-length ASCII file, the record size remains the same as it was
when specified.
The value specified for this
itemnum
is ignored when a byte stream file or
hierarchical directory is created. Byte stream files are created with a
logical record size of one byte (1). Hierarchical directories are created with
a logical record size of 32 bytes (32).
Default: 256
(ASC) For terminal and printer files, no rounding up occurs if a record size
consisting of an odd number of bytes is specified. The record size can be
different from the port configuration. The default is the configured record
size (normally 40 words for terminals, 66 words for printers).
20/CA Device name:
Passes the logical device number, in ASCII form, of a specific device. The
file is assumed to be permanent. If the device name option is specified, the