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OpenVMS System Manager's Manual

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5.6.4 Adding Comments to Compaq Supplied Messages

You can add comments to Compaq supplied messages documentation. Comments display with change bars immediately following the Compaq supplied description. This feature is a handy way to publicize a site-specific solution for a common problem.


Currently, user-supplied comments to Compaq supplied .MSGHLP$DATA files are not preserved through the next upgrade. However, if the Compaq supplied message descriptions do not change during the upgrade, you can reuse .MSGHLP files to reinsert comments after the upgrade.

How to Perform This Task

  1. Extract the message to which you want to add a comment. The following example extracts hypothetical message NOSNO:

  2. Edit the .MSGHLP file to add your comment. The .MSGHLP file format uses a unique numerical prefix to designate the message, facility, explanation, and user action sections of the message description. Add your comments at the end using a "5" prefix.

    1NOSNO, can't ski; no snow
    2XCSKI, XCSKI Program
    3Your attempt to ski failed because there is no snow.
    4Wait until there is snow and attempt the operation again.
    5If you don't want to wait, go to a location where there is
    5snow and ski there.
    5Or, try ice skating instead!

    Tips for modifying files:
    • Limit your comments to 60 characters per line so that they do not exceed the terminal display area.
    • Use a "5" prefix on blank lines too.
    • Do not edit Compaq supplied data. Any such edits are ignored when the comment is added to the database. Section 5.6.5 describes how you can alter Compaq supplied data.
  3. Update the database by inserting the updated message:


    The comment is now displayed following the Compaq supplied message description.



[Edit ACCVIO.MSGHLP to add your comment.]


5.6.5 Changing Compaq Supplied Data

You cannot use the procedure described in Section 5.6.4 to alter Compaq supplied information. The recommended way to permanently change Compaq supplied information is to send your comments to the OSSG Documentation Group (see the Preface for Internet and mail addresses) or contact a Compaq support representative.

The sequence described in this section allows you to modify Compaq supplied data, with the following results:

  • The Compaq supplied message is deleted from the database and your version of the message is inserted.
  • The message you modify subsequently displays with change bars to designate it as unsupported, user-supplied data.


    Currently, the Compaq supplied message is reinserted into the database at the next upgrade and the user-supplied text is overwritten.

How to Perform This Task

  1. Extract the message having the text or description you want to change:

    HELP/MESSAGE/EXTRACT=filename.MSGHLP search-string

  2. Check the .MSGHLP file to ensure that your search did not pick up any messages that you do not want to change. Delete any such messages that you want to preserve out of the .MSGHLP file.
  3. Delete the Compaq supplied version of the message from the Help Message database by specifying the .MSGHLP file as input. The following command deletes all messages in the .MSGHLP file from the default .MSGHLP$DATA file:


  4. Edit the .MSGHLP file to make your changes.
  5. Insert the revised message description into the Help Message database:


    Your version of the message now appears in the database with change bars to indicate that it is not a Compaq supplied message.



[Edit NOFILES.MSGHLP to change the text.]


5.6.6 Adding Messages to Compaq Supplied Database Files

The OpenVMS System Messages: Companion Guide for Help Message Users describes how to create your own .MSGHLP$DATA files to add new messages to the Help Message database. Keeping your messages in a separate file can simplify your messages bookkeeping and ensure that your messages are preserved through future upgrades.

With write access to Compaq supplied .MSGHLP$DATA files, you can alternatively insert your own messages into the Compaq supplied MSGHLP$LIBRARY.MSGHLP$DATA file. However, messages inserted using this technique will currently be overwritten at the next upgrade. You can, however, save your input .MSGHLP files and repeat the insertion process at the next upgrade.

How to Perform This Task

  1. Create a .MSGHLP file with your message descriptions in it. ( Section 5.6.4 includes an example of the .MSGHLP file format.)
  2. Specify your .MSGHLP file as input to update the Compaq supplied .MSGHLP$DATA file. Assuming that MSGHLP$LIBRARY.MSGHLP$DATA is the default, all you must enter is:




5.7 Customizing Mail

OpenVMS contains two logical names to enable you to customize the operation of certain Mail functions on your system. This includes checking the network address format to use and sending mail directly to a user on an OpenVMS Cluster (rather than through the network) if the sender and recipient are both on the same node.


You customize Mail by defining the logical name MAIL$SYSTEM_FLAGS as a system and executive mode logical name. For example:


The value of the logical name MAIL$SYSTEM_FLAGS is interpreted in the following ways:

Value Meaning
1 Indicates that this node is part of a homogeneous OpenVMS Cluster system. In other words, all disks are accessible to the cluster, and a common SYSUAF file and a common mail file exist for the cluster.

When this bit is set, the system checks the node to which you are sending mail to see if it is currently in the cluster. If the node is in the cluster, the system bypasses DECnet, and the message is written directly to the recipient's mail file. (Note that the node must be up to determine whether it is part of the cluster.)

2 Directs Mail to set the OpenVMS Cluster system breakthrough flag when issuing the $BRKTHRU service to notify the recipient of new mail. This flag is used only in OpenVMS Cluster systems and, typically, only in homogeneous OpenVMS Cluster systems (in other words, flag 1 is also set).
4 Directs Mail to include the time the message was delivered in the notification message displayed on the recipient's terminal.
+ 8 Directs Mail to use DECnet VAX address syntax when the system is running DECnet-Plus.
+16 Directs Mail to use DECnet-Plus address syntax.

+VAX specific

For example, if MAIL$SYSTEM_FLAGS translates to 7, the system selects the first three flags. If the logical name does not translate, the default is 0, which indicates that no flags are set.

On VAX systems, if neither 8 nor 16 is in the value for MAIL$SYSTEM_FLAGS, the system checks to see whether DECnet for OpenVMS or DECnet-Plus is running on the system and operates as if the appropriate bit were set. If MAIL$SYSTEM_FLAGS accidently specifies both DECnet and DECnet-Plus, the Mail utility defaults to DECnet-Plus.


Certain network addresses can be interpreted by the Mail utility as either DECnet-Plus names or SMTP names. These ambiguous network names have the following features:

  • The address does not contain double quotation marks (")
  • The address contains an at sign (@)
  • There are no periods to the right of the at sign

You can control the default system interpretation of those names with the MAIL$INTERNET_MODE logical name.

To specify the mail address mode, define logical name MAIL$INTERNET_MODE as follows:


You must have SYSNAM privilege or write (W) access to the system logical name table. The following table describes the values of address_mode and the effect of each value of MAIL$INTERNET_MODE.

Address Mode Effect
HYBRID (default) If the node component of the address contains a period (.), Mail uses SMTP address mode. If there are no periods, Mail uses DECnet address mode.
DECNET Mail always interprets the node component of the address as a DECnet node specification.
SMTP Mail always interprets the node component of the address as an Internet address specification. The default address mode is SMTP unless you use logical name MAIL$INTERNET_TRANSPORT to define a different transport (and therefore different address mode).

For more information about using logical names to control the use of internet address modes by the Mail utility, see the OpenVMS User's Manual.

5.8 Setting Up the Multipurpose Internet Mail Extension (MIME) Utility

MIME is the standard used to attach nontext files to mail messages to send them over the Internet. The MIME utility allows users to read and compose MIME-encoded mail messages on OpenVMS systems.

Understanding the MIME Utility

With MIME, users can encode and send nontext files such as graphics or audio files encoded as plain text; however, those files are often unreadable. The MIME utility decodes MIME files sent over the Internet to their original form. MIME also allows users to create MIME-encoded files, which can be sent as mail messages using the OpenVMS Mail utility.

For more information on how users can use the MIME utility, refer to the OpenVMS User's Manual.

5.8.1 Defining a Foreign Command

Your only installation work is to define a foreign command to run the utility, for example:


You can establish systemwide defaults for displaying MIME-encoded messages by creating two files: MIME$MAILCAP.DAT and MIME$FILETYPES.DAT.

MIME$MAILCAP.DAT identifies an application to display each locally recognized content-type of incoming MIME-encoded files. MIME$FILETYPES.DAT associates a content-type with the file extension of outgoing files.

A user can override those defaults by creating these files in SYS$LOGIN. See the OpenVMS User's Manual for details about those files.

5.9 Saving Your Customization

Once you have installed and customized your system, Compaq recommends that you back up your system disk. To do so, follow the instructions in Section 11.17.

On VAX systems, back up the console volume (if applicable). If your computer has a console storage device, make a backup copy of your console volume in case your original becomes corrupted. The operating system provides a command procedure called CONSCOPY.COM (in the SYS$UPDATE directory), which copies your console volume to a blank one.

The procedure for backing up the console volume varies for different computers. For specific instructions on backing up the console volumes, refer to the upgrade and installation supplement for your VAX computer.

Chapter 6
Setting System Time

This chapter describes how to control system time on OpenVMS systems, describes how system time relates to Universal Coordinated Time (UTC), and tells how to ensure that local system time remains correct when local time changes, as for daylight saving time. This chapter describes the following tasks:

Task System Section
Setting time zone information OpenVMS Alpha Version 7.3 Section 6.2
Setting time zone information OpenVMS Alpha before Version 7.3 and OpenVMS VAX Section 6.3
Setting time zone information OpenVMS Cluster Section 6.4
Controlling daylight saving time conversions All Section 6.5
Setting time using the Battery-Backed Watch (BBW) OpenVMS Alpha Section 6.6
Choosing languages, and date and time formats OpenVMS Section 6.7
Saving your time customizations OpenVMS VAX and Alpha Section 6.8
Using SYSMAN to manage system time   Section 6.9

6.1 Setting Correct Time Zone Information on Your System

Beginning with OpenVMS Version 7.0, Comapq C RTL implements its default date/time support for programs compiled with Compaq C Version 5.2 and later using a model based on Coordinated Universal Time (UTC), an international standard for measuring time of day.


Even if you do not use the Compaq C RTL directly, you must set correct time zone information on your system because other system utilities written in the Compaq C language might require it.

6.1.1 Distributed Time Synchronization Service (DTSS)

Your system may be using Distributed Time Synchronization Service (DTSS). DTSS is provided as an option with DECnet-Plus and the Distributed Computing Environment (DCE). If you are using DTSS, you must not use the procedures described in this chapter. Instead, use the procedures supplied with DTSS to set time zone information.

6.1.2 Understanding Time-Setting Concepts

Understanding some time concepts will help you see the importance of setting correct time zone information on your system. Coordinated Universal Time

Coordinated Universal Time (UTC) is similar in most respects to Greenwich Mean Time (GMT). Under the UTC time standard, zero hours occurs when the Greenwich Meridian is at midnight. Unlike local time, which can go backward and forward depending on daylight saving time, UTC always increases.

Local times can be up to 12 hours behind Greenwich Mean Time or 13 hours ahead of it.

Because UTC is independent of time zones, you can use UTC around the world; for example, it is 2:00 UTC at the same moment in Paris as it is in Tokyo. You can examine data that is time-stamped with UTC values in Paris and Tokyo without performing complicated conversions to deal with local time zones. Time Zones

Time zones for geographical areas that share the same local time also share the same rule or rules for seasonal changes between standard time and daylight saving time. Daylight Saving Time and Standard Time

Typically, you make seasonal changes to the local system time (for example, for daylight saving time and standard time). You usually adjust the local time one hour forward or backward. Time Differential Factor

One of the steps in setting the correct time on your system is to calculate a time differential factor (TDF) for your time zone.

The TDF associates each local time zone with UTC; it is the difference between your local system time and UTC. When your system time changes to reflect a local time change between standard time and daylight saving time, the TDF must also change to compensate for the new local system time. The TDF changes in the same direction as the local time; that is, if you add an hour to the local time, you must also add an hour to the TDF. Note, however, that the UTC does not change.

The TDF value is expressed in signed (+ or -) hh:mm format. The Americas have negative TDFs, while Europe, Africa, Asia, and Australia have positive TDFs.

OpenVMS procedures calculate the normal TDFs for standard and daylight saving time (if any) for your time zone. These are presented as the default for your TDF setting. Compaq recommends that you accept this default.

You can also use the map in Figure 6-1 to determine the TDF for your time zone. If you prefer, you can use the tables in Appendix B in the OpenVMS System Manager's Manual to determine the standard or daylight saving time TDF for your time zone.

To use the map to determine the TDF of your time zone, follow these steps:

  1. Find your location on the map and notice the time zone band at that location.
  2. Follow the time zone band to the top of the map and note the TDF that corresponds to your time zone. For example, the TDF for California is --8:00; the TDF for Italy is +1:00.

Some time zones do not have full-hour TDFs. In these cases, find the specific value on the map itself. For example, if you live in Adelaide, Australia, your TDF is +9:30.

In a time zone with daylight saving time, the TDF for daylight saving time is typically +1:00 from the standard time. For example, if the standard time TDF is +2:00, the daylight saving time TDF is +3:00; if the standard time TDF is -7:00, the daylight saving time TDF is -6:00.

Figure 6-1 Time Differential Factor Map


Time zone rules are under control of each country and are subject to change for political and other reasons. Printed maps are almost inevitably out-of-date. For up-to-date information, see the following web location:

  http://aa.usno.navy.mil/AA/faq/docs/world_tzones.html Time Zone Rules

A time zone rule is used to define the short name (usually three letters) for the time zone, the daylight saving time and standard time TDFs, and the rule for determining when changes are made between daylight saving time and standard time. The format of the time zone rules are defined in the DEC C Run-Time Library Reference Manual for OpenVMS Systems. Setting Time Zone Information

How you set the time zone information on your system depends on the following:

  • Whether DTSS is in use
  • The version of OpenVMS
  • The architecture (VAX, Alpha, or OpenVMS Cluster)


If you are using the Distributed Time Synchronization Service (DTSS), use the procedures supplied with DTSS to set time zone information. See Section 6.1.1.

If DTSS is not in use, use the following table to determine how to set time zone information

OpenVMS Version Architecture See
7.3 Alpha Section 6.2
7.3 VAX Section 6.3
7.2 and earlier VAX or Alpha Section 6.3
All OpenVMS Cluster Section 6.4

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