HP 3000 Manuals

Introduction to MPE XL for MPE V Programmers Migration Guide

HPFOPEN (NM) 
(new) 

The HPFOPEN intrinsic is an enhanced version of the FOPEN intrinsic.  It
is available in NM only.  It establishes access to a file on any device
and creates a file on any shareable device.

You can use the HPFOPEN intrinsic to access either a disk file or a
device file.  It enables you to create a new file on a shareable device
and define the physical characteristics of that file prior to access.
HPFOPEN returns to the calling process a file number that uniquely
identifies the file.  You can use the file number to reference the file
in calls to other intrinsics.

HPFOPEN's optional parameters are a superset of options provided in the
FOPEN intrinsic.  For example, the mapped access option is available
through HPFOPEN but not through FOPEN. In addition, some options
available through FOPEN are enhanced in the equivalent HPFOPEN options: 

 *  The blockfactor parameter allows you a maximum blocking factor of
    32,767 (FOPEN allows you 255).

 *  The domain option allows you to create a file that is immediately
    placed in the PERMANENT file directory.

 *  The access type option allows you EXECUTE-READ access.


NOTE  The FOPEN intrinsic is still available in MPE XL, but HPFOPEN is
      the recommended intrinsic for file access because it is more
      flexible and extensible than FOPEN. HPFOPEN is available in NM
      only.


HPFOPEN has an optional status parameter, a 32-bit signed integer passed
by reference.  Using the status parameter replaces using condition codes.
The parameter has two fields.  One reports the presence of errors and
warnings, and the other indicates their source.

The status parameter is optional, but recommended.  If an error or
warning condition is encountered, and you did not specify the status 
parameter, your process will abort.

MPE/iX 5.0 Documentation