[Comp.Sci.Dept, Utrecht] Note from archiver<at>cs.uu.nl: This page is part of a big collection of Usenet postings, archived here for your convenience. For matters concerning the content of this page, please contact its author(s); use the source, if all else fails. For matters concerning the archive as a whole, please refer to the archive description or contact the archiver.

Subject: OpenVMS Frequently Asked Questions (FAQ), Part 5/11

This article was archived around: Sun, 04 Sep 2005 19:59:10 GMT

All FAQs in Directory: dec-faq/vms
All FAQs posted in: comp.os.vms, comp.sys.dec
Source: Usenet Version


Archive-name: dec-faq/vms/part5 Posting-Frequency: quarterly Last-modified: 02 Sep 2005 Version: VMSFAQ_20050902-05.TXT
System Management Information ________________________________________________________________ Table 5-1 (Cont.) PCSI Generation Number _______________________________________________________ Generation Number____________Generation_Source____________________ 0050160000 V7.2-2 005017xxxx V7.2-2 ECOs 0060000000 V7.3 006001xxxx V7.3 ECOs 0060020000 V7.3-1 006003xxxx V7.3-1 ECOs 0060100000 V7.3-2 006011xxxx V7.3-2 ECOs 0070040000 V8.2 007005xxxx V8.2 ECOs 0070060000 V8.2-1 _________007007xxxx________V8.2-1_ECOs__________________________ __________________________________________________________ 5.29 How can I tell what software (and version) is installed? There is unfortunately no consistent nor single way to make this determination-this is one of the reasons that a move to PCSI installations is underway. On OpenVMS Alpha, you can use VMSINSTAL.HISTORY and PRODUCT SHOW PRODUCT to determine what packages have been installed via the VMSINSTAL and PCSI tools, respectively. To see which OpenVMS Alpha ECO kits have been applied, look in VMSINSTAL.HISTORY on OpenVMS Alpha prior to V7.1-2, and use PRODUCT SHOW PRODUCT/FULL on OpenVMS Alpha V7.1-2 and later. On OpenVMS VAX, you can use PRODUCT SHOW PRODUCT and (for software that is installed via VMSINSTAL on V7.3 and later) in VMSINSTAL.HISTORY. 5-44 System Management Information For products installed on OpenVMS VAX prior to V7.3 using VMSINSTAL, there is no reliable way to determine what products have been installed. If the product provides a RELEASE_NOTES file (as many do), you can look for the list of these files via DIRECTORY SYS$HELP:*.RELEASE_NOTES. Again, this approach is NOT reliable: some kits do not provide release notes, some system managers will install only the release notes, some system managers will delete release notes, and release notes for multiple versions can be present. On most packages, you can generally use ANALYZE/IMAGE on one of the core images, looking at the image identification area. Some of the product-specific mechanisms available are: o DQS DQS$VERSION logical name o C CC/VERSION o C++ CXX/VERSION o TCP/IP TCPIP SHOW VERSION command __________________________________________________________ 5.30 What file checksum tools are available for OpenVMS? The undocumented (prior to V8.2) DCL command CHECKSUM is the usual means, and provides a rather simple-minded checksum suitable to detect basic file corruptions. Starting with V8.2, additional algorithms beyond the classic XOR scheme are available. One of the most common schemes beyond the CHECKSUM XOR scheme is MD5, and information and a source code example are available via the MD5 RFC. As of this writing, pre-built versions of MD5 are expected to be made available at or via the OpenVMS Freeware website ( http://www.hp.com/go/openvms/freeware/ ), and MD5 is expected to be made available on an OpenVMS Freeware release after V7.0. Also see the CHECKSUM/ALGORITHM=MD5 command on OpenVMS V8.2 and later. 5-45 System Management Information The OpenVMS Alpha ECO (patch) kit checksums available at the ECO website are determined using the following DCL command sequence: $ CHECKSUM kitname.pcsi-dcx_axpexe $ SHOW SYMBOL CHECKSUM$CHECKSUM See Section 5.17 for information on acquiring OpenVMS ECO (patch) kits. __________________________________________________________ 5.31 What (and where) is the OpenVMS Management Station? For information and current kits for the OpenVMS Management Station (OMS), a PC-based tool that permits you to manage an OpenVMS system, please see: o http://www.openvms.compaq.com/openvms/products/argus/ __________________________________________________________ 5.32 How to determine current disk fragmentation level? The HP OpenVMS Disk File Optimizer (DFO) defragmentation package provides a fragmentation monitoring tool, and a DFO product authorization key (PAK) is not required for the fragmentation reporting tool: $ DEFRAG SHOW/VOLUME ddcu: The DFU tool available on the OpenVMS Freeware can generate a report on the disk fragmentation: DFU> REPORT ddcu: __________________________________________________________ 5.33 SYSBOOT-I-FILENOTLOC, Unable to locate SYS$CPU_ROUTINES? A message at the OpenVMS Alpha bootstrap such as the following: %SYSBOOT-I-FILENOTLOC, Unable to locate SYS$CPU_ROUTINES_1C02.EXE %SYSBOOT-E-LDFAIL, failed to load execlet, status = 00000910 5-46 System Management Information indicates that the particular OpenVMS Alpha release does not contain support for the target platform. In this case, OpenVMS does not recognize Alpha family 1C member 02 as a supported platform. A later version of OpenVMS might support the platform, or there might be no support on any release. Ensure that you have the most current firmware, and review the minimum version requirements for the platform. The execlet load failure and other similar bootstrap status values can often be decoded using either of the following techniques: $ exit %x910 %SYSTEM-W-NOSUCHFILE, no such file $ $ x = f$message(%x910) $ show symbol x X = "%SYSTEM-W-NOSUCHFILE, no such file" $ Also see Section 14.4.4.1. __________________________________________________________ 5.34 How can I customize the DCPS device control for a new printer? To customize DCPS for an otherwise unsupported printer, you can try the following sequence: o Extract the most closely-associated setup modules from the existing device control library, DCPS$DEVCTL.TLB. (For instance, you can probably extract and use the HP LaserJet 4000 series definitions for the HP LaserJet 4050 series. Each printer will vary, please consult the printer documentation for specifics and requirements.) o rename each extracted setup module to a corresponding: LPS$$UNRECOGNIZED_* 5-47 System Management Information o Insert all of the above-renamed setup modules into a newly-created device control library specific to the new printer: $ LIBRARY/TEXT/CREATE - SYS$COMMON:[SYSLIB]HP4050_DEVCTL.TLB LPS$$UNRECOGNIZED* The above assumes the filename HP4050_DEVCTL.TLB, alter as required. o Set up your DCPS startup procedures to include a search-list logical name such as: $ DEFINE/SYSTEM/EXECUTIVE DCPS_HP4050_LIB - SYS$LIBRARY:HP4050_DEVCTL.TLB, - SYS$LIBRARY:DCPS$DEVCTL.TLB o Supply DCPS_HP4050_LIB as the library parameter in the queue startup for this printer, this is the P3 parameter to the command procedure SYS$STARTUP:DCPS$EXECUTION_QUEUE.COM. o The HP4050_DEVCTL library may/will need to be recreated and modules re-edited and replaced with each DCPS upgrade, particularly if any modules are updated in the original library. You will also want to determine if the upgraded version of DCPS directly supports the particular printer. o To customize the processing of file extensions within DCPS (to enable or disable graybar output, for instance), use the information available in: SYS$LIBRARY:DCPS$FILE_EXTENSION_DATA_TYPE.DAT_DEFAULT to create your own site-specific: SYS$LIBRARY:DCPS$FILE_EXTENSION_DATA_TYPE.DAT Also see Section 5.15. __________________________________________________________ 5.35 Why do $GETDEV MOUNTCNT and SHOW DEVICE mount counts differ? MOUNTCNT returns the local mount count, while SHOW DEVICE returns the cluster-wide mount count. 5-48 System Management Information __________________________________________________________ 5.36 What software is needed for Postscript printers? The NorthLake PrintKit (www.nls.com) and DECprint Supervisor (DCPS) are common choices for support of Postscript printers on OpenVMS. o http://www.nls.com/ o http://www.openvms.compaq.com/openvms/Print/print_ sw_prods.html You may also require the installation of an IP transport stack. Also please see Section 15.2.2 and Section 15.2.3. __________________________________________________________ 5.37 How do I remove a PCSI-installed patch (ECO) kit? You cannot PRODUCT REMOVE a PCSI patch (ECO) kit. In order to remove an ECO kit, PCSI would have to have copies of all the other version of the files from all other patches and products that previously were installed. This can clearly involve a large number of files and a large archive of old file versions and a substantial quantity of disk space. While removal is clearly theoretically possible, it is not currently implemented. The following is the supported mechanism to remove a PCSI patch kit. 1 Execute a PRODUCT SHOW PRODUCT product-name. /FULL command. The "maintenance" column (132 column width) shows the patches that have been installed. Keep a copy of this listing. 2 Acquire kits for all of the maintenance kits listed. 3 Re-install the prior FULL version of the product. This will remove all patch kits, setting to product back to "original" condition. 4 Re-install all the patches in the list from step 1, except those patches which you have determined you do not want. 5-49 System Management Information The above information also applies to PCSI PARTIAL kits. __________________________________________________________ 5.38 SYSINIT-E, error mounting system device, status=0072832C This message can arise during an OpenVMS system bootstrap... %MOUNT-F-DIFVOLMNT, different volume already mounted on this device For details and further information, use the DCL command: $ HELP/MESSAGE /STATUS=%X72832C __________________________________________________________ 5.39 Resolving License PAK Problems? The PAK release date, the PAK termination date, and the PAK version are the usual culprits when a license product authorization key (PAK) check failure occurs. The PAK termination date is the date when the license PAK will expire. The PAK release date is the date of the most recent release date of the software package that will be permitted by the particular license PAK. (The release date check is analogous to a product version check.) The PAK version indicates the most recent product version that is permitted by the license. Having multiple license PAKs registered (and active) can also cause problems if an expired PAK gets loaded. You will want to DISABLE license PAKs you do not wish to have loaded. Other problems include a failure to register each PAK in all license databases throughout a multiple-system- disk cluster, with a consistent set of /INCLUDE lists specified across each of the duplicated PAKs. Additionally, you could have an invalid LMF$LICENSE logical name defined. (If no LMF$LICENSE logical name is defined, the standard license database named SYS$SYSTEM:LMF$LICENSE.LDB will be used.) 5-50 System Management Information You can display license failures by defining the following logical name: $ DEFINE/SYS/EXEC LMF$DISPLAY_OPCOM_MESSAGE TRUE Enable your terminal as a license operator (REPLY/ENABLE=LICENSE), define the LMF$DISPLAY_ OPCOM_MESSAGE logical name, and then try the failing operation again. You should see one or more OPCOM messages displayed. If you have the LMF$DISPLAY_OPCOM_MESSAGE logical name defined, you can (will?) see spurious license check failures-various products will check for multiple licenses, and a few products will check for PAKs that either have not yet been or will not be issued. Once you figure out which license has failed, you will want to deassign this logical name. Note That there are no license check failures does not indicate that the particular product or operation or use is permissible per applicable licensing agreements. Please consult the applicable agreement(s) for licensing-related information and requirements. To register a license PAK on a DECwindows system when DECwindows cannot start (because of an expired license or other licensing problem), follow the steps outlined in section Section 5.6 up through the use of the AUTHORIZE command. In place of the AUTHORIZE command, use the console to register the license PAKs. Also see Section 12.4 for licensing and troubleshooting information. For information on licensing and on the numbers of license units required for various products and various platforms, the License Unit Requirements Table (LURT) is available at: o http://www.compaq.com/products/software/info/ 5-51 System Management Information __________________________________________________________ 5.40 Changing the OpenVMS Version Number? Fool your friends, baffle your enemies, run the OpenVMS version of your choice! On OpenVMS Alpha systems: $ SET DEFAULT SYS$COMMON:[SYS$LDR] $ RUN SYSVER REPLACE V9.9 WRITE $ EXIT On OpenVMS VAX systems: $ set default SYS$COMMON:[SYS$LDR] $ copy SYS.EXE SYS.EXE_IN-CASE-I-FAIL $ patch SYS.EXE define sys$gq_version=800044b8 set mode ascii !examine sys$gq_version !examine sys$gq_version+4 deposit sys$gq_version = "V9.9" deposit sys$gq_version+4 = " " update exit $ Exit Then reboot the system at your leisure. __________________________________________________________ 5.41 How to prevent users from choosing obvious passwords? To prevent users from selecting obvious passwords on OpenVMS, you will want to use the reserved password (password screening) mechanism. Effectively, you merge your list of reserved passwords into the existing reserved words database maintained by OpenVMS. (You can also then require all users to reset their passwords- via the pre-expired password mechanism-thus forcing users to select new passwords.) For details on the password screening mechanism, of the reserved password database (VMS$PASSWORD_DICTIONARY.DATA), and details of how to merge your list of prohibited passwords into the database, please see the associated chapter in the OpenVMS security manual. For details of the 5-52 System Management Information password expiration mechanism, see the AUTHORIZE command qualifier /PWDEXPIRED. You can also implement a site-specific password filter with the information provided in the back of the OpenVMS Programming Concepts manual. The password filter permits you to establish particular and site- specific password requirements. For details, please see the system parameter LOAD_PWD_POLICY and the programming concepts manual, and see the examples in SYS$EXAMPLES:. (Examples and documentation on V7.3 and later reflect both platforms, the examples are found only on OpenVMS VAX kits on earlier releases. The capabilities have existed on both the VAX and Alpha platforms for some time now.) To verify current passwords, you can also use a technique known to system crackers as the "dictionary attack" - the mechanism that makes this attack somewhat more difficult on OpenVMS is the hashing scheme used on OpenVMS, and the file protections used for the SYSUAF authorization database. Given a dictionary of words and the unprotected contents of the SYSUAF file, a search for obvious passwords can be performed. Interestingly, a "dictionary attack" also has the unfortunate side- effect of exposing the password to the user-while this is clearly the goal of a system cracker, authorized privileged and non-privileged system users should not know nor have access to the (cleartext) passwords of other users. Accordingly, OpenVMS does not store the cleartest password. Further, OpenVMS uses a password hashing algorithm, not an encryption algorithm. This means that storage of a cleartext password is deliberated avoided, and the cleartext value is deliberately very difficult to obtain. The hash is based on a Purdy Polynomial, and the hash itself includes user-specific values in addition to the password, values that make the results of the password hash unique to each user. Regardless of the use of a password hashing scheme, if a copy of your password file should become available to a system cracker, you will want to force all users to use new passwords immediately. 5-53 System Management Information If you should require a user to verify a password, use the username, the user's salt value (this value is acquired via $getuai) and the user's specified cleartext password, and compare the resulting hashed value (using a call to $hash_password) against the saved hashed password value (this value also acquired via $getqui). For reasons of security, avoid saving a cleartext password value in any data files, and do not maintain the cleartext password in memory longer than required. (Use of sys$acm on V7.3-1 and later is recommended.) Kerberos authentication (client and server) is available on OpenVMS V7.3 and later. Integration of Kerberos support into various Compaq and into third- party products is expected. External authentication is available in V7.3-1 and later, with support for user-written external authentication in V7.3-2 and later. If you are simply looking for OpenVMS access and the SYSTEM and all other privileged passwords are forgotten or otherwise unavailable, please see section Section 5.6 and/or the OpenVMS documentation set. Also please see the NCSC C2 guidelines in the OpenVMS security manual. __________________________________________________________ 5.42__Please_help_me_with_the OpenVMS BACKUP utility? 5.42.1 Why isn't BACKUP/SINCE=BACKUP working? If you are seeing more files backed up than previously, you are seeing the result of a change that was made to ensure BACKUP can perform an incrementation restoration of the files. In particular, if a directory file modification date changes, all files underneath it are included in the BACKUP, in order to permit incremental restoration should a directory file get renamed. 5-54 System Management Information _____________________________ 5.42.1.1 Why has OpenVMS gone through the agony of this change? When a directory is renamed, the modified date is changed. When the restoration needs to restore the directory and its contents, and the restoration should not result in the restoration of the older directory name when a series of incremental BACKUPs are restored. Thus an incremental BACKUP operation needs to pick up all of the changes. Consider performing an incremental restoration, to test the procedures. This testing was how OpenVMS Engineering found out about the problem that was latent with the old BACKUP selection scheme-the old incremental BACKUP scheme would have missed restoring any files under a renamed directory. Hence the change to the selection mechanisms mentioned in Section 5.42.1. _____________________________ 5.42.1.2 Can you get the old BACKUP behaviour back? Yes, please see the /NOINCREMENTAL qualifier available on recent OpenVMS versions (and ECO kits). Use of this qualifier informs BACKUP that you are aware of the limitations of the old BACKUP behaviour around incremental disk restorations. _____________________________ 5.42.2 What can I do to improve BACKUP performance? Use the documented commands in the manual for performing incremental BACKUPs. Use the documented incremental procedures. Don't try to use incremental commands in a non-incremental context. Also consider understanding and then using /NOALIAS, which will likely be a bigger win than will anything to do with the incremental BACKUPs, particularly on system disks and any other disks with directory aliases. See the OpenVMS documentation for additional details. 5-55 System Management Information Ignoring hardware performance and process quotas, the performance of BACKUP during a disk saveset creation is typically limited by three factors: 1 Default extend size The default behavior can have poor performance, as the extend operation can involve extensive additional processing and I/O operations. Consider changing the default extend value on the volume, or change the extend for the process: $ set rms/extend=65000 2 Output IO size The default IO size for writing an RMS sequential file is 32 blocks, an increase from the value of 16 blocks used on earlier versions. Setting this to the maximum of 127 can reduce the number of IOs by almost a factor of 4: $ set rms/block=127 Note that the performance might be better on some controllers if the block count is a multiple of 4 - e.g. 124 3 Synchronous writes to the saveset Starting with OpenVMS V7.3, you can now persuade RMS to turn on write-behind for sequential files opened unshared. (Please see the V7.3 release notes or more recent documentation for details.) Enabling the write-behind operations involves setting the dynamic system parameter RMS_SEQFILE_WBH to 1. This parameter is dynamic, and it can be enabled and disabled without a reboot, and changes in its setting can and will directly effect the running system. In order to get the full benefit from write- behind operations, you also need to increase the RMS local buffer count from the default of 2 to a larger number. Raising the value to 10 is probably a reasonable first estimate for this value. 5-56 System Management Information $ run sys$system:sysman PARAMETERS USE ACTIVE PARAMETERS SET RMS_SEQFILE_WBH 1 PARAMETERS WRITE ACTIVE EXIT $ SET RMS/BUFFER=10/EXTEND=65000/BLOCK=127 $ BACKUP source-specification ddcu:[dir]saveset.bck/SAVE _____________________________ 5.42.3 Why is BACKUP not working as expected? First, please take the time to review the BACKUP documentation, and particularly the BACKUP command examples. Then please download and install the most current BACKUP eco kit. Finally, please please set the process quotas per the System Management documentation. These steps tend to resolve most problems seen. BACKUP has a very complex interface, and there are numerous command examples and extensive user documentation available. For a simpler user interface for BACKUP, please see the documentation for the BACKUP$MANAGER tool. As for recent BACKUP changes, oddities, bugs, etc: o A change made in OpenVMS V6.2 WILL cause more files to be included into a file-based BACKUP saveset using /SINCE=BACKUP as all files underneath any directory with a sufficiently recent (selected) date will be included in the saveset. This change was deliberate and intentional, and was mandated by the need to provide a functional incremental restoration. Without the inclusion of these apparently-extra files, an incremental saveset can NOT be reliably restored. o As part of the OpenVMS V6.2 change, the /SINCE command-without the specification of the =BACKUP keyword-selected more files than it should have. This is a bug. This bug has been remedied in the OpenVMS BACKUP source code and in some of (all of?) the BACKUP ECO kits. 5-57 System Management Information When working with BACKUP, you will want to: o Ensure you have your process quotas set per the recommendations in the OpenVMS System Management documentation. Deviation from these values can and will lead to access violation (ACCVIO) and other untoward behaviour. o Get the current BACKUP ECO kit and install it BEFORE you attempt to troubleshoot any problems. o Learn about the /NOINCREMENTAL (new) and /NOALIAS (V6.2 and later) command qualifiers. The former qualifier returns to the pre-V6.2 behaviour of the /SINCE file selection mechanism, while the latter (specified with /IMAGE) reduces the replication of files on system disks and other disks with file alias and directory alias entries. Both of these can reduce the numbers of files that will be selected and thus included into the saveset. Learn what /IGNORE=INTERLOCK means. This command probably does not provide what you think it does- those file system interlocks that this command is ignoring were implemented for a reason, after all. Ignoring these interlocks can lead to missed data and potentially to corruptions to individual files stored within the output saveset, corruptions that may or may not be reported. For details on this BACKUP command qualifier, please see the Ask The Wizard topic (2467). When working with the BACKUP callable API: o Build your applications with the most current BACKUP API available. Changes made to the V7.1-2 and V7.2 API were incompatible with the V7.1 and V7.2-1 and later APIs, and this incompatibility was repaired via a BACKUP ECO kit. Do NOT build your application with the versions of the BACKUP API that shipped with V7.1-2 and V7.2, as these are incompatible with the BACKUP API constants that were used on other versions. 5-58 System Management Information _____________________________ 5.42.4 How do I fix a corrupt BACKUP saveset? BACKUP savesets can be corrupted by FTP file transfers and by tools such as zip (particularly when the zip tool has not been asked to save and restore OpenVMS file attributes or when it does not support OpenVMS file attributes), as well as via other means of corruptions. If you have problems with the BACKUP savesets after unzipping them or after an FTP file transfer, you can try restoring the appropriate saveset attributes using the tool: $ @RESET_BACKUP_SAVESET_FILE_ATTRIBUTES.COM This tool is available on the OpenVMS Freeware (in the [000TOOLS] directory). The Freeware is available at various sites-see the Freeware location listings elsewhere in the FAQ-and other similar tools are also available from various sources. In various cases, a SET FILE/ATTRIBUTES command can also be used. As the parameters of this command must be varied as the target BACKUP saveset attributes vary, this approach is not recommended. Also see the "SITE VMS", /FDL, and various other file- attributes options available in various FTP tools. (Not all available FTP tools support any or all of these options.) Browser downloads (via FTP) and incorrect (binary or ascii FTP transfer modes) are notorious for causing RMS file corruptions and particularly BACKUP saveset corruptions. You can sometimes help encourage the browser to select the correct FTP transfer type code (via RFC1738): o ftp://host/urlname.ext;type=i ! request ftp image/binary transfer o ftp://host/urlname.ext;type=a ! request ftp ascii/text transfer 5-59 System Management Information You can also often configure the particular web browser to choose the appropriate transfer mode by default, based on the particular file extensions, using a customization menu available in most web browsers. You can select that the specific file extentions involved use the FTP binary transfer mode, which will reduce the number of corruptions seen. _____________________________ 5.42.5 How do I write a BACKUP saveset to a remote tape? How to do this correctly was described at DECUS long ago. On the OpenVMS host with the tape drive, create the following SAVE-SET.FDL file: RECORD FORMAT fixed SIZE 8192 Then create BACKUP_SERVER.COM: $ ! $ ! BACKUP_SERVER.COM - provide remote tape service for BACKUP. $ ! $ set noon $ set rms/network=16 $ allocate mka500 tapedev $ mount/nounload/over:id/block=8192/assist tapedev $ convert/fdl=SAVE-SET sys$net tapedev:save-set. $ dismount/unload tapedev $ stop/id=0 On the node where you want to do the backup, use the DCL command: $ backup - srcfilespec - node"user pwd"::"task=backup_server"/block=8192/save One area which does not function here is the volume switch; multi-reel or multi-cartridge savesets. Since the tape is being written through DECnet and RMS and the magtape ACP, BACKUP won't see the media switch and will split an XOR group across the reel boundary. BACKUP might well be willing to read such a multi- reel or multi-cartridge saveset (directly, not over 5-60 System Management Information the net) as the XOR blocks are effectively ignored until and unless needed for error recovery operations. BACKUP likely will not be able to perform an XOR-based recovery across reel or cartridge boundaries. Unfortunately BACKUP can't read tapes over the network because the RMS file attributes on a network task access look wrong; the attributes reported include variable length records. _____________________________ 5.42.6 How to perform a DoD security disk erasure? Sometimes refered to as disk, tape, or media declassification, as formatting, as pattern erasure, or occasionally by the generic reference of data remanence. Various references to the US Deparment of Defence (DoD) or NCSC "Rainbow Books" documentation are also seen in this context. While this erasure task might initially appear quite easy, basic characteristics of the storage media and of the device error recovery and bad block handling can make this effort far more difficult than it might initially appear. Obviously, data security and sensitivity, the costs of exposure, applicable legal or administrative requirements (DoD, HIPPA or otherwise), and the intrinsic value of the data involved are all central factors in this discussion and in the decision of the appropriate resolution, as is the value of the storage hardware involved. With data of greater value or with data exposure (sometimes far) more costly than the residual value of the disk storage involved, the physical destruction of the platters may well be the most expedient, economical, and appropriate approach. The unintended exposure of a bad block containing customer healthcare data or of credit card numbers can quite be costly, of course, both in terms of the direct loss, and the longer-term and indirect costs of such exposures. 5-61 System Management Information Other potential options include the Freeware RZDISK package, the OpenVMS INITIALIZE/ERASE command (and potentially in conjunction with the $erapat system service) and OpenVMS Ask The Wizard (ATW) topics including (841), (3926), (4286), (4598), and (7320). For additional information on sys$erapat, see the OpenVMS Programming Concepts manual and the OpenVMS VAX examples module SYS$EXAMPLES:DOD_ERAPAT.MAR. Some disk controllers and even a few disks contain support for data erasure. Some DSSI Disk ISEs, for instance. For the prevention of casual disk data exposures, a generic INITIALIZE/ERASE operation is probably sufficient. This is not completely reliable, particularly if the data is valuable, or if legal, administrative or contractual restrictions are stringent-there may well be revectored blocks that are not overwritten or not completely overwritten by this erasure, as discussed above, and these blocks can obviously contain at least part of most any data that was stored on the disk - but this basic disk overwrite operation is likely sufficient to prevent the typical information disclosures. You will want to consult with your site security officer, your corporate security or legal office, with HP Services or your prefered service organization, or with a firm that specializes in erasure or data declassification tasks. HP Services does traditionally offer a secure disk declassification service. _____________________________ 5.42.7 How to enable telnet virtual terminals? To enable virtual terminal support for telnet and rlogin devices, add the following logical name definitions into SYLOGICALS.COM: $ DEFINE/SYSTEM/EXECUTIVE TCPIP$RLOGIN_VTA TRUE $ DEFINE/SYSTEM/EXECUTIVE TCPIP$TELNET_VTA TRUE See SYS$STARTUP:SYLOGICALS.TEMPLATE for details on the typical contents of SYLOGICALS.COM. 5-62 System Management Information In SYSTARTUP_VMS.COM, ensure that a command similar to the following is invoked: $ SYSMAN IO CONNECT VTA0/NOADAPTER/DRIVER=SYS$LOADABLE_IMAGES:SYS$TTDRIVER.EXE In MODPARAMS.DAT, add the following line or (if already present) mask the specified hexidecimal value into an existing TTY_DEFCHAR2, and perform a subsequent AUTOGEN with an eventual reboot: TTY_DEFCHAR2 = %X20000 This value is TT2$M_DISCONNECT. On older TCP/IP Services-versions prior to V5.0-you will have to perform the following UCX command: $ UCX UCX> SET CONF COMM/REMOTE=VIRTUAL _____________________________ 5.42.7.1 Volume Shadowing MiniCopy vs MiniMerge? MiniMerge support has been available for many years with OpenVMS host-based volume shadowing, so long as you had MSCP controllers (eg: HSC, HSJ, or HSD) which supported the Volume Shadowing Assist known as "Write History Logging". If you are interested in mini-merge and similar technologies, please see the Fibre Channel webpage and the information available there: o http://www.openvms.compaq.com/openvms/fibre/ Mini-Merge support was originally intended to be controller-based and was expected with HSG80 series storage controllers and was expected to require ACS 8.7 and OpenVMS Alpha V7.3-1. Host-based Mini-Merge (HBMM) is now available for specific OpenVMS releases via a shadowing ECO kit, and is also present in OpenVMS V8.2 and later. HBMM applies to the HSG80 series and-like host-based volume shadowing-to most other (all other?) supported storage devices. 5-63 System Management Information The following sections describe both Mini-Copy and Mini-Merge, and can provide a basis for discussions. _____________________________ 5.42.7.1.1 Mini-Copy? A Shadowing Full Copy occurs when you add a disk to an existing shadowset using a MOUNT command; the entire contents of the disk are effectively copied to the new member (using an algorithm that goes through in 127-block increments and reads one member, compares with the target disk, and if the data differs, writes the data to the target disk and loops back to the read step, until the data is equal for that 127- block section). (This is one of the reasons why the traditional recommendation for adding new volumes to a shadowset was to use a BACKUP/PHYSICAL copy of an existing shadowset volume, simply because the reads then usually matched and thus shadowing usually avoided the need for the writes.) If you warn OpenVMS ahead of time (at dismount time) that you're planning to remove a disk from a shadowset but re-add it later, OpenVMS will keep a bitmap tracking what areas of the disk have been modified while the disk was out of the shadowset, and when you re-add it later with a MOUNT command OpenVMS only has to update the areas of the returned disk that the bit- map indicates are now out-of-date. OpenVMS does this with a read source / write target algorithm, which is much faster than the shenanigans the Full Copy does, so even if all of the disk has changed, a Mini-Copy is faster than a Full Copy. _____________________________ 5.42.7.1.2 Mini-Merge? A Shadowing Merge is initiated when an OpenVMS node in the cluster (which had a shadowset mounted) crashes or otherwise leaves unexpectedly, without dismounting the shadowset first. In this case, OpenVMS must ensure that the data is identical, since Shadowing guarantees that the data on the disks in a shadowset will be identical. In a regular Merge operation, Shadowing uses 5-64 System Management Information an algorithm similar to the Full Copy algorithm (except that it can choose either of the members' contents as the source data, since both are considered equally valid), and scans the entire disk. Also, to make things worse, for any read operations in the area ahead of what has been merged, Shadowing will first merge the area containing the read data, then allow the read to occur. A Merge can be very time-consuming and very I/O intensive. If a node crashes, the surviving nodes can query to determine what exact areas of the disk the departed node was writing to just before the crash, and thus Shadowing only needs to merge just those few areas, so this tends to take seconds, as opposed to potentially requiring many minutes or even hours for a regular full Merge. __________________________________________________________ 5.43 Please explain DELETE/ERASE and File Locks? DELETE/ERASE holds the file lock and also holds a lock on the parent directory for the duration of the erasure. This locking can obviously cause an access conflict on either the file or on the directory- it might well pay to rename files into a temporary directory location before issuing the DELETE/ERASE, particularly for large files and/or for systems with multiple overwrite erase patterns in use; for any systems where the DELETE/ERASE erasure operation will take a while. __________________________________________________________ 5.44 Managing File Versions? Some applications will automatically roll file version numbers over, and some will require manual intervention. Some will continue to operate without the ability to update the version, and some will be unable to continue. Some sites will specifically (attempt to) create a file with a version of ;32767 to prevent the creation of additional files, too. 5-65 System Management Information To monitor and resolve file versions, you can use commands including: $ SET FILE/VERSION_LIMIT=n filename $ SET DIRECTORY/VERSION_LIMIT=n [directory] And you can also monitor file version numbers, and can report problems with ever-increasing file versions to the organization(s) supporting the application(s) generating files with ever-increasing version numbers for details on potential problems, and for any recommendations on resetting the version numbers for the particular product or package. If required, of course. The following pair of DCL commands-though obviously subject to timing windows- can be used to rename all the versions of a file back down to a contiguous sequence of versions starting at 1: $ RENAME file.typ;* RENAME.TMP; $ RENAME RENAME.TMP;* file.typ; The key to the success of this RENAME sequence is the specification of (only) the trailing semicolon on the second parameter of each of the RENAME commands. You may also see the numbers of files reduced with DELETE commands, with multiple directories, or with PURGE commands such as the following examples: $ PURGE/BEFORE="-2-" $ PURGE/BEFORE="TODAY-2-" $ PURGE/KEEP=10" You can use DFU (Freeware) to quickly and efficiently scan for all files with large(r) version numbers: DFU SEARCH/VERSION=MINIMUM=nnnn If you are creating or supporting an application, selecting temporary or log file filenames from among a set of filenames-selecting filenames based on time, on process id, on the day of week, week number, or month, on the f$unique lexical (V7.3-2 and later), etc- is often useful, as this approach more easily permits on-line adjustments to the highest file versions and easily permits on-line version compression using 5-66 System Management Information techniques shown above. With differing filenames, you are less likely to encounter errors resulting from files that are currently locked. You can also detect the impending version number limit within the application, and can clean up older versions and roll the next file version creation to ;1 or such. Also see Section 9.4. __________________________________________________________ 5.45 Host-based Volume Shadowing and RAID? Host-based Volume Shadowing (HBVS) is Disk Mirroring is RAID Level 1. HBVS is capable of shadowing devices of different geometries, of different block counts (with dissimilar device shadowing; allowing for mixtures of hardware) and-with dynamic volume expansion-of growing volumes on the fly, and HBVS is capable of shadowing/mirroring/raid-1 operations across cluster configurations up to the full span-please see the Cluster SPD for the current supported span; the supported span limit is currently multiple hundreds of kilometers-of a cluster. HBVS can be layered onto controller (hardware) RAID, as well. For information on host-based striping, please see the StorageWorks RAID product. 5-67 _______________________________________________________ 6 Information on Mail __________________________________________________________ 6.1 MAIL keeps saying I have new messages, but I don't. What do I do? if you see the %MAIL-W-NONEWMAIL, no new messages error reported when MAIL indicates you have messages, then the NEWMAIL count has become skewed from reality. The count of new mail messages is kept separately from your mail folder, and is stored in VMSMAIL_ PROFILE.DATA. It sometimes happens that this count differs from what is stored in your mail folder. If this arises, invoke MAIL and repeatedly enter the READ/NEW command (or press the keypad hyphen key on an LK-compatible keyboard) until you see no new mail messages. Then enter the command one more time. This will resynchronize the counters. If you are operating in a cluster and find your mail counts inconsistent across cluster members, your customer is likely missing a definition of the VMSMAIL_ PROFILE logical name-and is probably also missing definitions of other logical names associated with other shared files-or has one or more inconsistent definitions of this and likely of other logical names. For details on the configuration data files that must be shared within a cluster, please see SYS$STARTUP:SYLOGICALS.TEMPLATE on V7.2 and later. __________________________________________________________ 6.2 How do I send or read attachments in VMS MAIL? Is there any way to send or read mail with files as attachments from VMS? 6-1 Information on Mail Not directly with the OpenVMS MAIL facility, but there are several other options: o Install PINE, available commercially from Innosoft or free from Andy Harper. With PINE you can both send and receive MIME messages, if you have the appropriate viewers available. o http://www.process.com/ o http://www.agh.cc.kcl.ac.uk/files/vms/pine-vms/ o ftp://ftp2.kcl.ac.uk/pub/vms/pine-vms/ o If you are working from an X Windows display, you can use the OpenVMS version of Netscape Navigator or Mozilla. The mail download protocol chosen to access the mail server from the Navigator or Mozilla mail client can be POP or IMAP, with the former causing messages to be downloaded while the latter permits messages to be retained on the mail server. Most folks prefer IMAP for this reason. o MPACK/MUNPACK. To send a MIME mail, construct the message with attachments manually using MPACK. You cannot send the resulting file directly through MAIL because an extra blank header line will be inserted between your message and the OpenVMS MAIL headers, which will cause the message to appear as plain text in most mail programs. Some TCP/IP stacks provide a work around for this problem, and if that doesn't work, you should generally be able to force the message directly into the SMTP port of your mail machine. Examples of both methods are in: o http://saf.bio.caltech.edu/pub/software/openvms/mmail.com To read a MIME mail message, open it in MAIL, extract it to a file, then use MUNPACK to break out and decode the attachments. MPACK/MUNPACK tools are also available on OpenVMS Freeware V5.0. o With OpenVMS V7.2 and later, use the MIME tool supplied with OpenVMS. 6-2 Information on Mail __________________________________________________________ 6.3 How can I block SMTP mail relay spam? Use the anti-spam capabilities present in the TCP/IP Services V5.1 and later SMTP servers. Use a firewall. On earlier TCP/IP Services releases, some simple DCL can reportedly prevent relay SMTP spam. Use the UCX command SHOW SERVICE SMTP/FULL to find the directory containing the UCX$SMTP_RECV_STARTUP.COM file, and insert the following DCL: $ ! $ ! Block spam. $ ! $ MY_ADDRESS_LONG[0,32]=F$INTEGER(F$TRNLNM("SYS$REM_NODE")-"::") $ MY_ADDRESS=F$FAO("!UB.!UB.!UB.!UB",F$CVUI(0,8,MY_ADDRESS_LONG),- F$CVUI(8,8,MY_ADDRESS_LONG),F$CVUI(16,8,MY_ADDRESS_LONG),- F$CVUI(24,8,MY_ADDRESS_LONG))'" $ MY_ADDRESS_REVERSE=F$FAO("!UB.!UB.!UB.!UB",- F$CVUI(24,8,MY_ADDRESS_LONG),F$CVUI(16,8,MY_ADDRESS_LONG),- F$CVUI(8,8,MY_ADDRESS_LONG),F$CVUI(0,8,MY_ADDRESS_LONG))'" $ WRITE SYS$OUTPUT F$TIME()+" "+F$TRNLNM("SYS$REM_NODE")+MY_ADDRESS $ UCX SHOW HOST 'MY_ADDRESS_REVERSE'.INPUTS.ORBS.ORG $ IF $STATUS.EQ.1 $ THEN $ WRITE SYS$OUTPUT "SPAM from relay rejected" $ EXIT $ ENDIF $ UCX SHOW HOST 'MY_ADDRESS_REVERSE'.SPAMSOURCES.ORBS.ORG $ IF $STATUS.EQ.1 $ THEN $ WRITE SYS$OUTPUT "SPAM source relay rejected" $ EXIT $ ENDIF $ ! $ ! Run receiver. $ ! $ run sys$system:ucx$smtp_receiver.exe $ goto exit 6-3 _______________________________________________________ 7 Information on Utilities __________________________________________________________ 7.1 How do I play an audio CD on my workstation? If you've installed the DECwindows examples, you'll find DECW$CDPLAYER.C, .DAT, .EXE, .UIL, and .UID. Copy the .UID and .DAT files to DECW$USER_DEFAULTS: (typically SYS$LOGIN:), define the logical name DECW$CD_PLAYER to be the device name of your CD-ROM drive (eg. DKA400:), give yourself PHY_IO and DIAGNOSE privileges, and run the .EXE. (These privileges are required, as the access to the CD-related extensions will require the use of the privilege-protected IO$_ DIAGNOSE I/O function code.) You can also install the image with these privileges. See the source for additional details - note that the comments regarding the need for SYSGEN CONNECT are no longer applicable (at least as of VMS V5.5-2). There's also SYS$EXAMPLES:CDROM_AUDIO.C and .EXE, a non-Motif program, available on OpenVMS VAX, and DECW$EXAMPLES:DECW$CDPLAYER.* on OpenVMS VAX and OpenVMS Alpha. The standard OpenVMS ATA (IDE) SYS$DQDRIVER device driver does not support the necessary does not support the necessary IO$_DIAGNOSE function code that is required for access to audio CD media commands (on OpenVMS versions prior to V7.3), but an updated SYS$DQDRIVER device driver (source code and all) with this capability and with the source code of an updated DECW$CDPLAYER CD audio player is available on the OpenVMS Freeware website (www.hp.com/go/openvms/freeware/, look for the directory /dqdriver/), and these updates are also included on OpenVMS Freeware V5.0, and OpenVMS ECO kits containing newer versions of the driver are available. Freeware V6.0 has a version of DQDRIVER that is newer than that of the OpenVMS Alpha V7.3-2 7-1 Information on Utilities release, with additional capabilities and with improved error diagnostics. OpenVMS Alpha V7.3 and later include a version of SYS$DQDRIVER with the necessary IO$_DIAGNOSE support. __________________________________________________________ 7.2 How do I access a Microsoft Windows floppy disk from OpenVMS? The HP Advanced Server (formerly known as PATHWORKS) for OpenVMS product includes an unsupported and undocumented utility called PCDISK, and this tool can read and write various Microsoft MS-DOS and Microsoft Windows FAT-format diskettes, and can usually access FAT-format volumes written by other operating systems. ProGIS in Germany sells a product called VMove which supports DOS files on many different device types. For more information, send mail to info@progis.de. Engineering Software has a product called VAKSAT which will read, write, and erase files on MS-DOS FAT diskettes. Available for both VAX and Alpha. Contact ed@cityscape.co.uk for more information. MadGoat PC Exchange (PCX) is a utility for copying files to and from MS-DOS and Microsoft Windows (FAT) format diskettes under OpenVMS, using an RX23 (3.5"), RX26 (3.5"), or RX33 (5.25") diskette drive. For 3.5" diskettes, high-density disks can be read or written; double-density disks are read-only. Only high-density disks are supported on the RX33. o http://www.madgoat.com/ The Freeware package WINFX is available on Freeware V6.0, and can read the FAT volume structure. o http://www.hp.com/go/openvms/freeware/ 7-2 Information on Utilities __________________________________________________________ 7.3 How do I play sound files on an AlphaStation? DECsound doesn't work. Various of the more recent AlphaStation systems use a different sound board (Microsoft Sound System) than the earlier DEC 3000 series systems, and DECsound, as supplied by DECwindows Motif, doesn't support this board nor this interface. HP offers an optional product, Multimedia Services (MMOV) for OpenVMS: o http://h18000.www1.hp.com/info/spd/ OpenVMS typically uses SPD 25.01.xx, SPD 41.87.xx, and SPD 82.35.xx. which provides a replacement for DECsound for this card as well as many other features (an AVI and MPEG player, video capture support, etc.) Ensoniq sound support is also available. __________________________________________________________ 7.4 How do I read IBM EBCDIC tapes on OpenVMS? Most (all?) IBM EBCDIC-based systems can read and write ANSI-labeled ASCII magtapes. Fixed-length records (MOUNT /FOREIGN /BLOCKSIZE=512 /RECORDSIZE=512, for one-block records) and the DCL COPY command can be used to transfer fixed-record-size text files out onto tape media, or to read from fixed-record tape media. Please consult the IBM documentation for the details and command syntax needed when reading and writing ANSI media using IBM JCL or other applicable IBM command language. There exists various freeware around (TAPECOPY, ETAPE, TCOPY, MTEXCH) that can read and write EBCDIC tapes. Visit the Encompasserve (DECUS) website software archives search engine and search for "EBCDIC" for details. o http://www.encompassus.org OpenVMS does not include an integrated tool for EBCDIC tape processing, but does provide a character conversion API useful within application programs. 7-3 Information on Utilities One source for ETAPE is: o http://www.ualr.edu/ftp/vms/ETAPE_SRC/ The OpenVMS Freeware V5.0 distribution included this ETAPE tool, as well. __________________________________________________________ 7.5 How can I patch an OpenVMS Alpha image? Using the OpenVMS Freeware tool ZAP: o Look for the RMS_TOOLS directory on Freeware V5.0: http://www.hp.com/go/openvms/freeware/ tell ZAP to read a block (bucket) of information based on the virtual block number (VBN), using X for hexadecimal. Dump yourself into the OpenVMS debugger with R2 pointing into the buffer, EXAMINE/INSTRUCTION as needed, alter the buffer as required, GO to get out of the debugger and back into ZAP, and use the ZAP W command to write the updated block. 7-4 _______________________________________________________ 8 DCL Details __________________________________________________________ 8.1 DCL Symbols and OpenVMS Logical Names? DCL symbols are programming-style variables implemented within the DCL command interpreter, and these are used both for programming and to provide command verb synonyms. Symbols are local to the command interpreter operating within a particular process, and are not shared. Lists of symbols can be copied into subprocesses during a subprocess creation operation, but these symbols are neither copied back into the parent process when the subprocess exits, nor are symbols ever shared across processes. Symbols can be specified in and utilized in basic mathematical operations, and bit-level operations are available with the f$cvsi and f$cvui bit extraction lexical functions, and with the square-brackets notation for bit insertion (see Section 8.13 for an example), and with bitwise operators. Symbols are of two basic types, STRING and INTEGER, and these (or an undefined symbol) can be differentiated with the f$type lexical function. DCL symbols can also be used as a mechanism to abbreviate a DCL command verb, or an easy way to invoke a DCL command procedure. Symbols can have local or global scope within a process, and scope is affected by nested procedure calls and DCL constructs such as CALL and SET SCOPE, but such discussions are beyond the scope of this section. OpenVMS Logical names can store device names, device and directory specifications, rooted or searchlist specifications, and full filenames. Logical names can also store arbitrary data, but there are no native mathematical or bitwise operators available. Analogous to DCL symbols, process-local logical names can be copied into subprocesses during a subprocess creation 8-1 DCL Details operation, but these process-local logical names are neither copied back into the parent process when the subprocess exits, nor are these logical names ever shared. Logical names are implemented deep within the OpenVMS executive, and are organized into logical name tables. Logical names can be stored in tables private to a process( LNM$PROCESS, the process-local logical name table) , that can be shared among processes in the same job tree ( LNM$JOB, the job logical name table) or in logical name tables that are shared among larger groups of processes (eg: LNM$GROUP, the UIC group logical name table and LNM$SYSTEM, the system-wide logical name table). Logical names are centrally intended to provide various I/O-related capabilities, including device independence and configuration customization-correctly- written application programs can use logical names to avoid embedding specific device or device and directory specifications, and to allow filename and configuration customizations. One of the most powerful capabilities of logical names beyond the device independence provided involves the defaulting capabilities; you can use RMS parsing (directly, or with mechanisms such as the f$parse lexical function) to provide a filename and a default filename. To provide the mechanism that allows SYSUAF to be located in an arbitrary position or even an arbitrary filename, a construct similar to the following is used: $ UAF = F$PARSE("SYSUAF","SYS$SYSTEM:.DAT") This design allows the logical name SYSUAF to be optionally defined, and - when present-to specify the particular location and name of the file. Portions of the full file specification that are omitted are retrieved using the default translation of SYS$SYSTEM: and the file type of .DAT. Logical names also have assigned processor modes, as some translations must be trustworthy. In the example above, only trusted and privileged system users should be able to redirect the SYSUAF authorization database, 8-2 DCL Details so any definition of the SYSUAF logical name must be made in EXECUTIVE mode in a trusted logical name table. As for common OpenVMS terminology, logical names are "defined" and the associated processing is refered to as "translation", while symbols are "equated" and the associated processing is refered to as "substitution". "Lexical functions" are processing routines built into DCL, and typically prefixed with f$. Many of the lexical functions are built upon correspondingly-named system services, though not all. Symbol substitution occurs only when the DCL command interpreter is reading and processing the command input; for information on DCL symbol substitution, see Section 8.10. For program access, see the RTL routines lib$set_symbol and lib$get_symbol.) For information on logical name translation, please see f$trnlnm lexical function and the DCL commands DEFINE and DEASSIGN, as well as underlying system services such as sys$trnlnm. Logical name translation occurs when requested, or as the file or I/O operation is started. Please see the OpenVMS User's Guide in the OpenVMS documentation set for a far more detailed description of these constructs. For related materials, please see Section 8.10 and Section 8.11. __________________________________________________________ 8.2 How do I run a program with arguments? The RUN command does not accept arguments. To pass arguments to a program, you must use what is called a "foreign command", and either an explicit command as shown here, or an automatic foreign command. For example: $ unzip :== $disk:[dir]unzip.exe $ unzip -? 8-3 DCL Details The leading $ in the equivilence name for the symbol definition is what makes the DCL symbol a foreign command. If the device and directory are omitted, SYS$SYSTEM: is assumed. Under OpenVMS V6.2 and later, DCL supports automatic foreign command definition via the logical name DCL$PATH. An example of a definition of this logical name is: $ DEFINE DCL$PATH SYS$DISK:[],ddcu:[mytooldir],SYS$SYSTEM: DCL will first look for a command in the DCL command table, and if no match is found and if DCL$PATH is defined, it will then look for command procedures and executable images with filenames matching the command specified, in the directories specified via DCL$PATH. The first match found is invoked, and under OpenVMS, the DCL$PATH support will cause a command procedure to be activated in preference to an executable image. For more information on foreign commands or on automatic foreign command support, see the OpenVMS User's Manual. See also Section 10.3. If you want to create a detached process that takes arguments from a command line, it must be run under the control of a command line interpreter (CLI) (typically DCL). This is done by placing the command line in a file, specifying SYS$SYSTEM:LOGINOUT.EXE as the image to run and the command file as the input. For example: $ OPEN/WRITE CMD TEMP_INPUT.COM $ WRITE CMD "$ MYCOMMAND arguments" $ CLOSE CMD $ RUN/DETACHED SYS$SYSTEM:LOGINOUT /INPUT=TEMP_INPUT.COM Various OpenVMS library calls (such as lib$spawn(), cli$dcl_parse(), and the C library system() call) require access to a command line interpreter such as DCL to perform requested actions, and will not operate if a CLI is not available. 8-4 DCL Details When a CLI is not available, these calls typically return the error status SS$_NOCLI. And as mentioned above, invoke the image LOGINOUT to cause a CLI (such as DCL) to be mapped into and made available in the context of the target process. For examples of how TCP/IP Services sets up its foreign commands (which includes tools such as uuencode and uudecode), please see the DCL command procedure SYS$STARTUP:TCPIP$DEFINE_COMMANDS.COM. Also see Section 8.12. __________________________________________________________ 8.3 How can I clear the screen in DCL? The simplest way is the TYPE/PAGE NLA0: command. You can set up a symbol to clear the screen in your LOGIN.COM: $ CLS :== TYPE/PAGE NLA0: __________________________________________________________ 8.4 Using REPLY/LOG from DCL? Disabling Console OPCOMs? Your terminal must be enabled as an operator terminal before the REPLY/LOG command can be used, but a DCL procedure (batch command file, system startup, etc) does not have an associated terminal. To make this work, use the following sequence to enable the OPA0: console as the operator terminal, then the REPLY/LOG command will be accepted: $ DEFINE/USER SYS$COMMAND _OPA0: $ REPLY/LOG $ DEFINE/USER SYS$COMMAND _OPA0: $ REPLY/ENABLE To disable the system console terminal (OPA0:) as an operator terminal, use the following command: $ DEFINE/USER SYS$COMMAND _OPA0: $ REPLY/DISABLE 8-5 DCL Details Also see SYLOGICALS.COM (and SYLOGICALS.TEMPLATE) for information on configuring the behaviour of OPCOM, including the (default) use of the system console (OPA0:) as an operator terminial and the specific contents and behaviour of the system operator log file OPERATOR.LOG. __________________________________________________________ 8.5 How do I generate a random number in DCL? With V7.3-2 and later, f$unique can be useful here. Alternatively, here is a pseudo-random number generator, just do a GOSUB RAND and the global symbol RANDOM will contain a randomly generated number. You can feed the generator a ceiling value (__CEIL) or a new seed (__SEED). $! RAND - returns a positive random number ("RANDOM") between 0 and $! __CEIL - 1. $! sharris-at-sdsdmvax.fb3.noaa.gov $ RAND: $ $ IF F$TYPE(__SEED) .EQS. "" $ THEN $ ! seed the random number generator, ... $ __NOW = F$CVTIME() $ __HOUR = 'F$EXTRACT(11,2,__NOW)' $ __MINUTE = 'F$EXTRACT(14,2,__NOW)' $ __SECOND = 'F$EXTRACT(17,2,__NOW)' $ __TICK = 'F$EXTRACT(20,2,__NOW)' $ $ __SEED == __TICK + (100 * __SECOND) + (6000 * __MINUTE) + - (360000 * __HOUR) $ ! the generator tends to do better with a large, odd seed, ... $ __SEED == (__SEED .OR. 1) $ ! clean up, ... $ DELETEX/SYMBOL __NOW $ DELETEX/SYMBOL __HOUR $ DELETEX/SYMBOL __MINUTE $ DELETEX/SYMBOL __SECOND $ DELETEX/SYMBOL __TICK $ ENDIF $ $ IF F$TYPE(__CEIL) .EQS. "" THEN __CEIL = %X3FFFFFFF 8-6 DCL Details $ $ __SEED == __SEED * 69069 + 1 $ $ RANDOM == (__SEED.AND.%X3FFFFFFF)/(%X40000000/__CEIL) $ $ RETURN __________________________________________________________ 8.6 What does the MCR command do? The MCR is an artifact of RSX compatibility mode, the operating system from which OpenVMS is descended. MCR is the Monitor Console Routine, and the command is intended to activate RSX compatibility mode utilities. When used on OpenVMS, the command is most commonly used to run the specified image and-because the tool detects the image is not a compatibility-mode image- it acts as a form of RUN command with the default file specification of SYS$SYSTEM:.EXE. MCR passes any (optional) command line arguments in a fashion similar to a foreign command. In other words: $ MCR FOO BAR is equivalent to: $ FOO :== $FOO $ FOO BAR MCR is not documented. Use of a foreign command or the DCL$PATH mechanism is preferred. For details on this, see Section 8.2. __________________________________________________________ 8.7 How do I change the OpenVMS system prompt? You can use the SET PROMPT command for this purpose. SET PROMPT sets the DCL prompt to the specified string. When you want to display variable information, you will need to establish a tie-in that provides the information to the SET PROMPT command as required. If you wish to display the default directory for instance, you will have to establish a tie between the SET DEFAULT command and the SET PROMPT commands, as there is no direct way to get the default directory as 8-7 DCL Details the DCL prompt. You can easily acquire or create a set of DCL command procedures that perform the SET DEFAULT and SET PROMPT for you. These DCL command procedures often use a command such as: $ set prompt='f$environment("default")' More advanced users could implement a system service or other intercept, and use these tools to intercept the directory change and reset the prompt accordingly. (This approach likely involves some kernel-mode programming, and requires write access to various undocumented OpenVMS data structures.) There are related tools available from various sources, including the following web sites: o ftp://ftp.hhs.dk/pub/vms/setpmt/ o ftp://ftp.tmesis.com/sys_service_hook.src o James F. Duff has also made available a Macro32 tool known as TIME_PROMPT, a tool that sets the prompt to the current system time. o Many folks have contributed DCL procedures to perform this task. Visit the newsgroup archives for information and examples. __________________________________________________________ 8.8 Can I do DECnet task-to-task communication with DCL? Yes, you can do this with DCL. The OpenVMS DECnet documentation shows various simple examples using the task object and the TYPE command to trigger the execution of a DCL command procedure on a remote node. An example DCL command procedure that is rather more advanced than using the TYPE command as a trigger is included in the Ask The Wizard area: o http://www.hp.com/go/openvms/wizard/ For additional information on the OpenVMS Ask The Wizard (ATW) area and for a pointer to the available ATW Wizard.zip archive, please see Section 3.8. 8-8 ---------------------------- #include <rtfaq.h> ----------------------------- For additional, please see the OpenVMS FAQ -- www.hp.com/go/openvms/faq --------------------------- pure personal opinion --------------------------- Hoff (Stephen) Hoffman OpenVMS Engineering hoff[at]hp.com