Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

262 Chapter9
Intrinsics Reference (cont)
HPFOPEN
4 Circular file (CIR).
6 Message file (MSG).
Item# = 11 access type option (I32)
Passes a value that specifies access restrictions for the
file. See Table 9-2 for a summary of how the access type
settings apply to terminals and printers.
0 Read access only.
1 Write access only.
2 Write access only, but previous data in
file not deleted
3 Append access only.
4 Input/output access.
5 Update access.
6 Execute access.
7 Execute-Read access. (Not included in
Table 9-2. Returns File System Error
40 if applied to an asynchronous
devicefile.)
8 Reserved for MPE/iX. No access; opens
the file without any access checking. A
process must be executing in system
code to use this access type.
Item# = 12 dynamic locking option I32 )
Not meaningful for asynchronous devices. If specified it
will be ignored.
Item# = 13 exclusive option (I32)
Passes a value indicating whether you have continuous
exclusive access to this file. This option does not apply
to printers. Exclusive access is available during the
first open issued against a terminal. If a session is
already running on a terminal, it is not possible to issue
another HPFOPEN (or FOPEN) with “exclusive”
specified. (See the MPE/iX Intrinsics Reference Manual
for more information on what each of the settings
implies.)
0 Default.
1 Exclusive access.
2 Semi-exclusive access.