HP OpenVMS Systems Documentation

OpenVMS User's Manual

Although DCL preserves the case of extended file names, wildcard matching is case blind.

A search operation with wildcards continues to match only against the corresponding character in the same part of the target file. Table 5-1 contains examples of some wildcard searches.

Both ODS-2 and ODS-5 volume structures support deep nesting of directories on OpenVMS Alpha, as follows:

• There can be up to 255 levels of directories.
• On ODS-2 the format for a directory name is 39.39.
• On ODS-5 the name of each directory can be up to 236 8-bit or 118 16-bit characters long.

For example, you can create the following deeply nested directory:

$ CREATE/DIRECTORY [.a.b.c.d.e.f.g.h.i.j.k.l.m]

You can create the following directory with a long name on an ODS-5 volume:

$ CREATE/DIRECTORY
[.AVeryLongDirectoryNameWhichHasNothingToDoWithAnythingInParticular]

Complete file specifications longer than 255 bytes are abbreviated by RMS when presented to unmodified applications.

5.2.1 Directory Naming Syntax

On an ODS-5 volume, directory names conform to most of the same conventions as file names when using the ISO Latin-1 character set. Periods and special characters can be present in the directory name, but in some cases, they must be preceded by a circumflex (^) in order to be recognized as literal characters, as shown in Table 5-2.

Under some circumstances, a full file specification may contain more characters than the 255 bytes allowed by unmodified applications. If a file specification that such an application needs exceeds 255 bytes in length, RMS generates a shorter file specification by abbreviating the directory to a Directory ID (DID), and if necessary, the filename to a File ID (FID).

When the file specification is too long, RMS first attempts to generate a shorter directory specification by identifying the directory with its directory ID. This shorter specification is referred to as a DID.

TEST$ODS5:[5953,9,0]Alghero.TXT;1

Note that this form of the directory name must have three numbers and two commas to avoid ambiguity with UIC format directory names. With the DIRECTORY command you can view the shorter DID version as well as the full version of a file specification.

5.3 Using the Extended File Specifications Parsing Feature in DCL

The default DCL parsing style for file names is for ODS-2 style file names.

When using extended file names on the DCL command line, you need to set the parsing style to EXTENDED to accept and display extended file specifications. To set the parsing style, enter the command:

$ SET PROCESS/PARSE_STYLE=EXTENDED

Note that this command has no effect on an OpenVMS VAX system.

After you enter the command, DCL accepts a file name such as the following:

$ CREATE MY^[FILE

For additional information, see the description of the SET PROCESS/PARSE_STYLE command in the OpenVMS DCL Dictionary: N--Z.

To reset DCL to the default parsing style, enter the following command:

$ SET PROCESS/PARSE_STYLE=TRADITIONAL

After you enter this command, DCL accepts only ODS-2 file name formats.

5.4 Where You Can Use Extended File Specifications

Some DCL commands and OpenVMS utilities fully support extended file specifications. They have been modified to take advantage of all the features of extended file names. They can accept and handle extended file specifications without error and without modifying their expected case. In addition, they can accept and produce long file specifications that exceed the traditional 255-byte limit in their original form¹--without requiring them to be abbreviated in Directory ID (DID) or File ID (FID) format.

DCL commands and OpenVMS utilities with default support have had little or no modification to take advantage of extended file names. 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, they might create or display file names with the wrong case.

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:

• 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-abbreviated form. This restriction specifically applies to matching operations that are performed outside of RMS.
• 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 a FID abbreviation is a unique numeric representation of one file, it cannot be used to represent or match any other file.
• Creating a file using a FID abbreviation is illegal.

For more information about DID and FID abbreviations, refer to the Guide to OpenVMS File Applications.

For more information on a specific command or utility, refer to the appropriate manual in the OpenVMS documentation set.

No Support for Extended File Naming

OpenVMS utilities and commands that do not support extended file names 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 on ODS-5 volumes because Compaq cannot ensure that they will function successfully when they encounter extended file specifications.

No Support for ODS-5

OpenVMS utilities and commands that do not support the ODS-5 volume structure cannot handle extended file names. These utilities and commands should be used carefully on ODS-5 volumes because Compaq cannot ensure that they will function successfully even when they only encounter traditional file specifications.

Table 5-3 lists the OpenVMS utilities and commands that do not support Extended File Specifications because of limitations with either extended file names or ODS-5.

5.5 Displaying Files with Extended Names

Some DCL commands have the following new qualifier to control the display of extended file names:

/STYLE= [CONDENSED | EXPANDED]

This qualifier allows you to control how the modified DCL commands display extended file names and any associated prompts.

The keyword CONDENSED displays the file specification as it is generated to fit within the 255-byte character string limit imposed by many utilities. When necessary, this file specification may contain a DID abbreviation or a FID abbreviation. The keyword EXPANDED displays the file specification that is stored on disk in full and does not contain a DID abbreviation or a FID abbreviation.

The following sections contain examples of using the /STYLE qualifier with the DIRECTORY, TYPE, PURGE, and DELETE commands.

5.5.1 DIRECTORY Command

The DIRECTORY command allows you to select in what format the file name is displayed when viewing the contents of a directory:

DIRECTORY/STYLE=(keyword[,keyword])

The DIRECTORY command by default displays file names as you see in the following example, using DIDs where necessary and switching back to the full directory specification where DIDs are not necessary:

$ DIRECTORY

Directory TEST$ODS5:[23,1,0]

abcdefghijklmnopqrstuvwxyABCDEFGHIJKLMNOPQRSTUVWXYabcdefghijklmnopqrs
tuvwxyABCDEFGHIJKLMNOPQRSTUVWXYabcdefghijklmnopqrstuvwxyABCDEFGHIJKLM
NOPQRSTUVWXY.abcdefghijklmnopqrstuvwxyABCDEFGHIJKLMNOPQRSTUVWXYabcdef
ghijklmnopqrst;2

Total of 1 file.

Directory TEST$ODS5:[TEST.RANDOMTESTING.RANDOM]

AddressFiles.DIR;1  LOGIN.COM;3         test.1;1       test^.1.clue;1
Travel.LIS;1        whee.;5       work.dat;8

Total of 8 files.

Grand total of 2 directories, 9 files.

The DIRECTORY command, using both keywords with the /STYLE qualifier, produces a two-column directory list. Each column lists all the file names. The CONDENSED column contains any needed DIDs or FIDs, while the EXPANDED column contains full directory names and file names. Any file errors are displayed in the CONDENSED column. The following example shows the results of the DIRECTORY command with the /STYLE qualifier taking both keywords:

$ DIRECTORY/STYLE=(CONDENSED,EXPANDED)

Directory TEST$ODS5:[23,1,0]        TEST$ODS5:[TEST.RANDOMTESTING.RANDO
                                    M]

abcdefghijklmnopqrstuvwxyABCDEFGHIJ abcdefghijklmnopqrstuvwxyABCDEFGHIJ
KLMNOPQRSTUVWXYabcdefghijklmnopqrst KLMNOPQRSTUVWXYabcdefghijklmnopqrst
uvwxyABCDEFGHIJKLMNOPQRSTUVWXYabcde uvwxyABCDEFGHIJKLMNOPQRSTUVWXYabcde
fghijklmnopqrstuvwxyABCDEFGHIJKLMNO fghijklmnopqrstuvwxyABCDEFGHIJKLMNO
PQRSTUVWXY.abcdefghijklmnopqrstuvwx PQRSTUVWXY.abcdefghijklmnopqrstuvwx
yABCDEFGHIJKLMNOPQRSTUVWXYabcdefghi yABCDEFGHIJKLMNOPQRSTUVWXYabcdefghi
jklmnopqrst;2                       jklmnopqrst;2
AddressFiles.DIR;1                  AddressFiles.DIR;1
LOGIN.COM;3                         LOGIN.COM;3
test.1;1                            test.1;1
test^.1.clue;1                      test^.1.clue;1
Travel.LIS;1                        Travel.LIS;1
whee.;5                             whee.;5
work.dat;8                          work.dat;8

Total of 8 files.

DIRECTORY can either use one or both keywords with the /STYLE qualifier.

5.5.2 TYPE Command

The TYPE command accepts the /STYLE qualifier to select the file name format displayed in system messages while typing files and prompts:

$ TYPE/STYLE=(keyword)

This example shows the use of the TYPE command with the TYPE=EXPANDED and CONFIRM qualifiers:

$ TYPE/CONFIRM/STYLE=EXPANDED abc*.*rst;2
TYPE TEST$ODS5:[TEST.RANDOMTESTING.RANDOM]abcdefghijklmnopqrstuvwxyzABCDEF
GHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYabc
defghijklmnopqrstuvwxyzGHIJKLMNOPQRSTUVWXYabcdefghijklmnopqrst;2 ? [N]: Y

[System outputs contents of file]

The DELETE command accepts the /STYLE qualifier to select the file name format for display purposes when performing the command:

$DELETE/STYLE=(keyword)

In the following examples, the ellipsis (...) represents many characters within the file name. These examples use the CONFIRM qualifier to generate a system message.

DELETE using default (CONDENSED):

$ DELETE/CONFIRM abc*.*.*
DELETE TEST$ODS5:[TEST.RANDOMTESTING.RANDOM]abcAlphabet.stuff;1 ? [N]: Y
DELETE TEST$ODS5:[23,1,0] abcdefg. . .QRSTUVWXY.abcdefg. . .tuvw
xy;1 ? [N]: Y

When the full file specification is required, use the DELETE command with the /STYLE qualifier and the EXPANDED keyword:

$ DELETE/CONFIRM/STYLE=EXPANDED abc*.*.*
DELETE TEST$ODS5:[TEST.RANDOMTESTING.RANDOM]abcAlphabet.stuff;1 ? [N]: Y
DELETE TEST$ODS5:[TEST.RANDOMTESTING.RANDOM]abcdefg. . .QRSTUVWX
Y.abcdefg. . .tuvwxy;1 ? [N]: Y

The PURGE command accepts the /STYLE qualifier to select the file name format for display purposes when performing the command:

$ PURGE/STYLE=(keyword)

In the following examples, the ellipsis (...) represents many characters within the file name. These examples use the CONFIRM qualifier to generate a system message.

PURGE using default (CONDENSED):

$ PURGE/CONFIRM
DELETE TEST$ODS5:[23,1,0]abcdefg. . .QRSTUVWXY.abcdefg. . .tuvwxy;1
? [N]: Y

When the full file specification is needed, use the PURGE command with the /STYLE qualifier and the EXPANDED keyword:

$ PURGE/CONFIRM/STYLE=EXPANDED
DELETE TEST$ODS5:[TEST.RANDOMTESTING.RANDOM]abcdefg. . .QRSTUVWXY.ab
cdefg. . .tuvwxy;1 ? [N]: Y

To display extended file names, your terminal must be set to display the ISO Latin-1 character set. Otherwise, the characters displayed on the terminal might not match those shown by a PC. To view or change the character set displayed on your terminal, use the terminal setup dialog box. The options for selecting the character set to display are usually found in the General tab.

The characters that differ between the DEC Multinational and ISO Latin-1 character sets are listed in Appendix A.

5.7 Working in Mixed Environments

If your system is running OpenVMS Alpha Version 7.2 or higher, you can take advantage of all extended file specifications capabilities on ODS-5 volumes. You also can continue to access pre-Version 7.2 files and directories. For example, you can do all of the following:

• Create and access deep directory structures on ODS-2 volumes
• Read a BACKUP saveset created on an earlier version of OpenVMS
• Copy a file with an ODS-5 name to a file with an ODS-2 name on a system running an earlier version of OpenVMS

If you are working in a mixed-version or mixed-architecture OpenVMS Cluster, there are some limitations. Systems running prior versions of OpenVMS cannot mount ODS-5 volumes, correctly handle extended file names, or even see extended file names. Users on a version of OpenVMS prior to Version 7.2 cannot access any files on an ODS-5 volume. This is true regardless of whether the volume is connected physically on a CI or SCSI bus, or by an MSCP or QIO server. Nor can these users create or restore an ODS-5 image saveset. However, they can restore ODS-2-compliant file names from an ODS-5 saveset.

OpenVMS Version 7.2 VAX systems are limited to the following extended file specifications functionality:

• Ability to mount an ODS-5 volume.
• Ability to write and manage ODS-2-compliant files on an ODS-5 volume.
• See pseudonames ( \pISO_LATIN\.??? or \pUNICODE\.??? ) when accessing an ODS-5 file specification.

When working in an environment that contains both OpenVMS Alpha and OpenVMS VAX systems, it is important to know the following:

• Your system type and operating system version
• Whether your default directory is ODS-2 or ODS-5 based
• Whether the destination for a file you are creating is an ODS-2 or ODS-5 volume

OpenVMS 7.2 allows VAX systems to mount ODS-5 volumes; however, users on OpenVMS VAX systems can access only files with ODS-2-compliant file names.

You can choose whether or not to convert a volume to ODS-5 on your OpenVMS Alpha systems. When working in a mixed environment of ODS-2 and ODS-5 volumes, keep in mind the restrictions of ODS-2 file names when creating files on ODS-5 volumes. If you copy a file that has special characters in its name from an ODS-5 to an ODS-2 volume, you must give it an ODS-2 compliant name.