HP OpenVMS Systems Documentation
OpenVMS Guide to Extended File Specifications
2.3 Controlling Access to ODS-5 Volumes
A system manager may choose to enforce one or both of the following restrictions:
The system manager can impose either of these restrictions by using normal OpenVMS discretionary controls. Refer to the OpenVMS Guide to System Security for more information.
Sections 2.3.1 and 2.3.2 contain examples of restricting
access to ODS-5 volumes.
Follow these steps to prevent a user from accessing an ODS-5 volume from a VAX node:
2.3.2 Preventing an Untested Application from Accessing an ODS-5 Volume
Follow these steps to prevent an untested application from accessing an ODS-5 volume:
You can also override the restriction in the last step to allow trained users to access untested applications by following the remaining steps:
After you complete these steps:
2.4 System Management Utility Changes
The following sections describe changes made to OpenVMS system
management utilities to support extended file names.
The following new qualifier has also been added:
This qualifier produces statistical information about the volume under verification and creates a file, STATS.DAT, which contains per-volume statistics. The information placed in STATS.DAT is the following:
2.4.2 Backup Utility (Alpha Only)
Following are new features the Backup utility (BACKUP) has implemented to support extended file names on Alpha systems:
2.4.3 Physical Backups of ODS-5 Volumes on VAX Systems
On OpenVMS VAX systems, BACKUP supports ODS-5 volumes only when you specify the /PHYSICAL qualifier to back up a volume. The BACKUP /PHYSICAL command causes BACKUP to make a block-by-block physical backup of the disk, ignoring the structured contents of the disk.
On Alpha systems, you can use either the BACKUP /IMAGE or BACKUP /PHYSICAL command.
See the Backup chapter of the OpenVMS System Manager's Manual for more information about
support for extended file names by the Backup utility on Alpha
The Mount utility has been modified to provide full support for ODS-5 volumes.
. , ; [ ] % ^ &
File names containing special characters cannot be accessed from a VAX system. See Section 3.3 for more information about mixed-architecture environments.
The use of the period (.) as a literal character in extended file names requires RMS to determine which periods are file name characters and which are delimiters.
When only one period (.) is used in an extended file name, that period is interpreted as the delimiter. As in previous versions of OpenVMS, this behavior also occurs if the single period is followed by a number:
$ CREATE Test.1
creates the file:
When there are multiple periods (.) in a file name, RMS looks at all the characters after the last period. If those characters are all numeric, or all numeric and preceded by a minus sign (-), the numeric string is determined to be a version number. However, if there are more than 5 numeric characters, RMS rejects the file name as illegal. If there is a nonnumeric character following the last period, then it is interpreted as a type delimiter.
For example, the following command: $ CREATE Test18.104.22.168
creates the file: Test4^.3.2;1
where .2 is the file type and 1 is the file version.
A version number explicitly delimited by a semicolon (;) must also be 5
or fewer numeric characters, and can be preceded by a minus sign (-).
22.214.171.124 Expanded File Specification Length
On an ODS-5 volume, the file name together with the file type can be up to 236 8-bit characters or 118 16-bit characters in length. Unmodified programs and utilities may limit or abbreviate complete file specifications to 255 bytes.
$ CREATE This.File.Name.Has.A.Lot.Of.Periods.DAT $ CREATE - _$ ThisIsAVeryLongFileName^&ItWillKeepGoingForLotsAndLotsOfCharacters.Exceed - _$ ingThe39^,39presentInPreviousVersionsOfOpenVMS $ DIRECTORY Directory TEST$ODS5:[TESTING] ThisIsAVeryLongFileName^&ItWillKeepGoingForLotsAndLotsOfCharacters.Exceeding The39^,39presentInPreviousVersionsOfOpenVMS;1 This^.File^.Name^.Has^.A^.Lot^.Of^.Periods.DAT;1 Total of 2 files.
Single- and multiple-character wildcards function as expected with
ODS-5 files. A single-character wildcard represents exactly one
character in either the file name or file type, but may not be used in
the file version string. A multiple-character wildcard can represent
any number of characters (including zero characters) in the file name
or file type. A multiple-character wildcard can be used in place of a
126.96.36.199.1 Wildcard Characters
The following characters are wildcard characters when working on any OpenVMS 7.2 volume:
The percent sign (%) continues to be a single-character wildcard to maintain compatibility with existing applications. The percent sign (%) may be used as a literal character when preceded by the circumflex (^) and is also a literal character in Windows NT file names. Therefore, in addition to the percent sign, RMS also recognizes the question mark (?) as a single character wildcard. The question mark functions identically to the percent sign as a wildcard character on OpenVMS 7.2 and later. The percent sign and the question mark each matches exactly one character in a search pattern.
An escaped character (such as ^.) or an escape sequence (such as ^EF or ^U0101) is considered a single character for purposes of wildcard matching.
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 specification. Table 3-1 contains examples of some wildcard searches.
|The pattern...||matches...||...but does not match|
On an ODS-5 volume, the case for all versions of a file name is identical; the case is preserved as the file name was first created. When you create more than one file with the same name differing only in case, DCL treats the subsequent files as new versions, and converts them to the same case as the original file.
For example, the following sequence of commands:
$ CREATE CaPri.;1 $ CREATE CAPRI $ CREATE capri
produces the resulting files:
CaPri.;1 CaPri.;2 CaPri.;3
In prior versions of OpenVMS, DCL and RMS converted all file
specifications to uppercase. On ODS-5 volumes, the case of all file
names is preserved as created by the user.
3.2 Directory Specifications
The following sections describe the deeper directory structures and
extended naming syntax available on ODS-5 volumes. It is now possible
to go beyond the eight levels of directories previously supported in
3.2.1 Deep Directory Structures
OpenVMS 7.2 supports deep nesting of up to 255 directories with the restriction that the total directory specification can be no longer than 512 8-bit or 16-bit characters.
For example, a user can create the following directories on an ODS-2 or ODS-5 volume:
$ CREATE/DIRECTORY [a.b.c.d.e.f.g.h.i.j.k.l.m]
A user can create the following directory with a long name on an ODS-5 volume:
$ CREATE/DIRECTORY - [.AVeryLongDirectoryNameWhichHasNothingToDoWithAnythingInParticular]
On ODS-5 volumes, directory names conform to most of the same conventions as file names when using the ISO Latin-1 character set. Periods and special characters may be present in the directory name, but they must be preceded by the escape character (^) in order to be recognized as literal characters, as shown in Table 3-2.
|CREATE/DIRECTORY. . .||Result|
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 DID, and if necessary, the filename to a 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.
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. See Section 3.6 for more information on displaying long file specifications. See Section B.2.2.7 for more information about DID abbreviations. See Section B.2.2.8 for more information about FID abbreviations.