MPE/iX Intrinsics Reference Manual (32650-90875)

376 Chapter7
Command Definitions (HP32208-HPLOACNMPROC)
HPFOPEN
3 Append access only, if the file's security provisions allow
either append or write access. FREAD, FREADDIR,
FREADSEEK, FUPDATE, FSPACE, FPOINT, and
FWRITEDIR intrinsic calls cannot reference this file. The
record pointer is set to EOF prior to each FWRITE. For disk
files, the EOF is updated after each FWRITE call.
Therefore, data cannot be overwritten.
4 Read/Write (I/O) access only, if the file's security
provisions allow both read and write access. If both read
and write access are not allowed, the access type is limited
to that specified in the security provisions (either read or
write). Any file intrinsic can be issued except FUPDATE for
this file. The EOF is not changed; the record pointer starts
at zero. This option is not valid for message files.
5 Update access only, if the file's security provisions allow
both read and write access. If both read and write access
are not allowed, the access type is limited to that specified
in the security provisions (either read or write). All file
intrinsics can be issued, including FUPDATE, for this file.
The EOF is not changed; the record pointer starts at zero.
This option is not valid for message files.
6 Execute access only, if the file's security provisions allow
execute access. This allows read/write access to any loaded
file. The program must be running in privileged mode to
specify execute access. This option is not valid for message
files.
7 Execute-Read access only, if the file's security provisions
allow execute access. This allows only read access to a
loaded file. The program must be running in PM to specify
execute-read access. This is changed to execute access for
KSAM, CIR, and RIO files. Not valid for message files.
8 Reserved for MPE/iX. No access, opens the file or directory
without any access checking. A process must be executing
in system code to use this access type.
9 Directory read access, opens a directory for directory read
access. Directories can only be opened for no access or
directory read access. Files cannot be opened for directory
read access.
FIFO files should be opened for Read Access Only (0) or Write Access Only
(1). Other access types can cause unexpected results to occur.
12/I32 Dynamic locking:
Passes a value enabling/disabling file locking for the file. When specified,
the FLOCK and FUNLOCK intrinsics can be used to dynamically
permit/restrict concurrent access to a disk file by other processes at
specified times.