HP 3000 Manuals HP 3000 Manuals
MPE/iX File Designators
The file system recognizes two general classes of files:
* user-defined files, which you or other users define, create, and
make available for your own purposes
* system-defined files, which the file system defines and makes
available to all users to indicate standard input/output devices
These files are distinguished by the file names and other descriptors
(such as group or account names) that reference them, as discussed below.
You may use both the file name and descriptors, in combination, as either
formal designators within your programs or as actual designators that
identify the file to the system. Generally, however, most programmers
use only arbitrary names as formal designators, and then equate them to
appropriate actual file designators at run time. In such cases, the
formal designators (user file names) contain from one to eight
alphanumeric characters, beginning with a letter; the actual designators
include a user or system file name, optionally followed by a group name,
account name, and/or security lockword, all separated by appropriate
delimiters. This technique facilitates maximum flexibility with respect
to file references.