VMS Help
Ext File Specs, Managing, Extended File Specifications Support
*Conan The Librarian
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To help determine the expected behavior of OpenVMS utilities
and commands for ODS-5, the following levels of support have
been established. Each level outlines the acceptable behavior
of a utility or command when it encounters an extended (ODS-5
compliant) file specification.
The levels of support for ODS-5 are defined in the following
sections:
OpenVMS utilities and commands that offer full support for ODS-5
have been specifically modified to take advantage of all the
features of extended file naming. These utilities and commands
should accept and handle extended file specifications without
error and without modifying their expected case.
In addition, OpenVMS commands and utilities that fully support
Extended File Specifications can accept and produce long file
specifications that exceed the traditional 255-byte limit in
their original form-without requiring them to be abbreviated in
Directory ID (DID) or File ID (FID) format.
OpenVMS utilities and commands with default support have had
little or no modification to take advantage of Extended File
Specifications features. These utilities and commands are
expected to handle most of the attributes of extended file
specifications (such as new characters and deep directory
structures) correctly. However, issues with case sensitivity
and case blindness (such as converting lowercase characters to
uppercase) may occur.
In contrast with utilities that have full support, utilities with
default support rely on DID and FID abbreviation offered by RMS
to handle long file specifications. As a result, these utilities
are subject to the following restrictions related to DID and FID
abbreviation:
o Matching operations in an environment where FID abbreviation
is used may not always work as expected. For example, wildcard
matching operations may not capture all target file names
because the long file names may be represented in their
numeric FID abbreviation form. This restriction specifically
applies to matching operations that are performed outside of
RMS.
o Wildcards and sticky defaults cannot be used with a FID
abbreviation. For example, the following commands are illegal:
$ DIRECTORY a[1,2,3]*.txt
$ COPY a[1,2,3].txt *.txt2
Because FID abbreviations are a unique numeric representation
of one file, they cannot be used to represent or match any
other file.
o Creating a file using a FID abbreviation is illegal.
3 - No Support for Extended File Naming
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OpenVMS utilities and commands that do not support extended
file naming can function on ODS-5 volumes; however, they are
restricted to operating with traditional file specifications
only. These utilities and commands should be used carefully
under Extended File Specifications because they may not function
successfully when they encounter extended file specifications.
OpenVMS utilities and commands that do not support the ODS-
5 volume structure cannot handle extended file naming. These
utilities and commands should be used carefully under Extended
File Specifications because they may not function successfully
on ODS-5 volumes even when they only encounter traditional file
specifications.
The following table lists the OpenVMS utilities and commands
that do not support Extended File Specifications because of
limitations with either handling extended file names or the ODS-5
volume structure.
Component Notes
No ODS-5 Support
Disk defragmenters Unsupported unless a specific
defragmentation tool documents that it has
been updated to support an ODS-5 volume.
No Extended File Naming Support
Code compilers Cannot use extended file names for object
files. However, code compilers can create
applications that support extended names.
INSTALL
Known images Do not rename to an extended file name.
LINK Cannot output an image with an extended
file name.
Network files Do not rename to an extended file name.
(NET*.DAT)
Object modules (.OBJ) Do not rename to an extended file name.
Page and swap files Do not use an extended file name.
SYSGEN Do not write a parameter file with an
extended file name.
System startup files Do not rename to an extended file name.