Accessing Files Programmer's Guide (32650-90885)
46 Chapter2
Creating A File
The HPFOPEN Intrinsic
executing in system code.
2 When this value is specified, the system attempts to let
the caller access the file as a native byte stream file. Byte
stream emulation is supported for ordinary fixed and
variable length record files as well as for files with the byte
stream record type. If this value is requested against a file
type that does not support byte stream access, an error is
returned.
Specifying any value other than the values described above will result in
an error.
79/I32 POSIX Non-Block Mode
Specifying this itemnum allows the caller to open a file with the POSIX
Non-Block mode. This item is useful for a subset of files (including pipes
and FIFO's) and is ignored for all other files. The behavior of the
HPFOPEN call with this option is dependent on the type of file being
opened.
The current valid values for this item are:
0 This value indicates that Non-Block mode is off. This is the
default value.
1 This value indicates that Non-Block mode is on.
Specifying any value other than those described above will result in error.8
80/I32 Reserved for the operating system.
81/I32 Symbolic link option:
This
itemnum
allows the caller to specify different options when traversing
through or opening a symbolic link. The valid values for this
itemnum
are
described below:
0 Follow symbolic links. This is the default value for this
option. When a symbolic link is encountered it is traversed
according to the path specified in the symbolic link.
1 Does not follow symbolic links. If the final component of a
path is a symbolic link, then no traversal is done and the
symbolic link is opened. Symbolic links that occur prior to
the last component is traversed.
Specifying any value other than those above will result in error.
82-86 Reserved for MPE/iX
87/@64 Large Mapped Access
Returns a pointer to the beginning of file data. This option can be used on
any sized file, but is the only means by which to open files larger than 4 gb
-64kb (4,294,901,760 bytes) for mapped access. Large mapped access
shares the same constraints on file types as the long mapped option
(option 21).