Accessing Files Programmer's Guide (32650-90885)

88 Chapter4
Specifying a File Domain
Permanent Files
Permanent Files
A permanent file exists as a file in the system file domain. Its existence is not limited to the
duration of its creating job or session, and depending on security restrictions, it may be
accessed by jobs or sessions other than the one that created it. Some or all of the space for
a permanent file has already been allocated, and its physical characteristics have been
defined.
The features of new, temporary and permanent files are listed in Table 4-1. on page 88
In some cases, the domain you can specify for a file may be restricted by the type of device
on which the file resides. The domains permitted are summarized in Table 4-1. on page 88
NOTE
*
When you specify a file domain using HPFOPEN, you should open only disk
files with the
domain option set to NEW. Device files can be opened with the
Table 4-1. Features of New, Temporary, and Permanent Files
New Files Temporary Files Permanent Files
Exists only to creating
process.
Exists as job temporary file. Exists as permanent file in
system.
Space not allocated yet. Space (some or all) already
allocated.
Space (some or all) already
allocated.
Physical characteristics not
previously defined.
Physical characteristics
defined.
Physical characteristics
defined.
Known only to creating job or
session.
Known only to creating job or
session.
Known system-wide.
Exists only for duration of
program execution.
Exists only for duration of
creating job/session.
Permanent.
Table 4-2. File Domains Permitted
Device Type Domain Permitted
Disk new, temporary, or permanent
Magnetic Tape Device
new
*
or permanent
Synchronous Single-Line Controller
new
*
or permanent
Programmable Controller
new
*
or permanent
Terminal
new
*
or permanent
Line Printer
new
*
Plotter
new
*