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- Introduction to VMS - Part I
- gr1p@b4b0.org
-
- People have been asking quite a few questions about VMS/openVMS recently.
- They are finding that some machines on University subnets are using OpenVMS
- and they don't have any experience with this operating system, hopefully
- this short guide will help a few people along and give them some introductory
- knowledge of VMS.
-
- VMS/OpenVMS is a multi-tasking/processing virtual memory operating
- system, VMS standing for Virtual Memory System. It is designed to be able
- to handle memory extensions beyond the capabilities of its processer (VAX -
- Virtual Address extension). This therefore allows it to run software and
- programs much larger than its physical memory and processer speed. VMS is
- also run on the ALPHA platform, which uses Advanced RISC Architecture
- which provides similar power to a VAX, but the ALPHA allows more
- flexibility and is slightly more technologically advanced than VAX in the
- fact that it can support installation of unix based Operating Systems as
- well as VMS. The Differences between running VMS on a VAX or an ALPHA
- platform are very small as most programs can just be recompiled and run
- to suit whichever architecture VMS is running on. The float-type's and
- Data Alignment technique's on VAX and ALPHA are slightly different, but
- close enough to coherantly exist without causing any complimation problems
- in Installation.
-
- VMS was first developed in 1976 by DEC (Digital Equipment Corporation) as
- part of their new 32 bit Virtual memory operating systems project. It has
- since been supported by many Academic Institutions and large financial
- companies due to its large power capabilities.
-
- It uses a command line scripting language called DCL (Digital Command
- Language) along with compiler capabilities in other more well-known
- programming languages such as Pascal, Cobal, Ada, Fortran, C, Basic etc.
-
- VMS is a very secure Operating System internally but it does often, by
- default have some easy to access default logins. (similar to how IRIX
- often has unpassword lp accounts etc.).
-
- Some default logins on VMS include..
-
- guest/guest
- guest/<nopasswd>
- operator/operator
- system/system
- system/manager
- system/operator
- support/support
- decnet/decnet
- field/field
- default/default
- operations/operations
-
- When entering a VMS system will be receive a login prompt/message similar
- to this..
-
- -=-=-
-
- Username: GUEST
- Password:
- Welcome to OpenVMS VAX V6.2
-
- Last interactive login on Monday, 14-SEP-1998 20:09
- Last non-interactive login on Tuesday, 15-SEP-1998 14:43
-
-
- There are new messages in folder BLAH.
-
- -=-=-
-
- You are the presented with a prompt looking this this..
-
- $
-
- .x BASIC VMS COMMANDS x.
-
- Below is a list of some basic commands that you will need to know to
- navigate you way around a VMS system from the command line prompt
- comfortably..
-
- HELP
-
- If in doubt, There is always the help screen.
-
- $ help
-
- This is large and offers detailed help on MANY commands which are not
- covered here.
-
- LOGOUT
-
- Logs the user out of the system.
-
- EDIT
-
- This brings up the VMS editor (which uses a VT-220 terminal)
-
- ACCOUNTING
-
- Accounting is the program that keeps logs of the usage users are making
- from the system.
-
- @
-
- This executes a DCL eg.
-
- $ @elitedcl.com
-
- This is just the same as running a unix style shell script at the command
- line or even a dos .exe/.com file at dos command line.
-
- DEL
-
- Deletes a file on the system eg.
-
- $ del file.dat
-
- RUN
-
- This will run an executable file.
-
- $ run elite.exe
-
- DIR
-
- Lists the contents of a directory.
-
- There are two widely used options that you should know here.
-
- /brief - gives a brief listing of the directory, similar to ls
- /full - gives a full listing of the directory, similar to ls -al
- but gives pages on information rather than a little
- permissions/size chart..
-
- SHOW
-
- The show command has quite a few options and can provide a lot of
- information about the system that you are on.
-
- The command must be followed by an option, and some options include..
-
- users - shows all online users at the current time.
- time - shows the current local time of the system.
- system - presents you with system information.
- memory - shows you the memory the machine is using/running.
- network - displays network information to which the VMS is connected.
- process - process <processname>, similar to unix ps command.
- devices - list of devices attached to the system.
- quota - disk quota of current user.
-
- TYPE
-
- This command will display a file at the terminal, it is the same as the
- unix cat command.
-
- $ type <filename>
-
- MAIL
-
- This will send mail to any machine connected to any shared network or to
- another local user on the system.
-
- SET FILE/PROTECTION
-
- This command sets permissions of files, similar to the unix chmod command,
- however it has different levels of permissions than standard unix
- permissions.
-
- The most common permission for a regular users file is..
-
- $ set file/protection=owner[rwed] leet.dat
-
- This sets the permission of leet.dat to read (r), write (w), edit (e),
- delete (d) permission of the user who owns the file. ie. owner
-
- Other possible permissions include..
-
- world - this (in place of owner) would make the file world (rwed?)
- group - this would give permission to people in the same user
- group
- system - this would give permission to all users with system
- access.
-
- eg. $ set file/protection=world[r] leet.dat
-
- Would result in leet.dat being world readable.
-
- PHONE
-
- Phone is a VMS chat program similar to the unix talk program.
-
- type $ phone
-
- and your prompt will change from a $ to a %
- at this point type the username of the person you wish to chat with, you
- can see if they are online via typing 'show users' beforehand.
-
- % guest
-
- would then start a talk session between yourself and the person logged in
- as guest.
-
- $PASSWORD
-
- This would change the password of the user you are logged in as.
-
- eg. $ $password fuqy0u
-
- Would result in your new password being fuqy0u.
-
- CREATE
-
- Create is the pascal compiler that is used to compile .pas files.
-
- $ create whatever.pas
-
- would then result in the production of an executable file from the .pas
- code.
-
- .x FILE EXTENSIONS x.
-
- Below is a list of common file extensions in a VMS enviroment, if I missed
- any common ones out I apoligise..
-
- com - A DCL Batch file.
- cld - A DCL descriptor file (much like a windoze .dll).
- dat - A general Data File.
- exe - An executable file.
- lis - System Directory listing file.
- dir - A directory/Subdirectory file
- tmp - A temporary storage file.
- txt - A simple text file, also used for outputted mail files.
- uaf - A user authorisation file.
- sys - A System Image file.
- mai - A Mail message file.
- edt - A command file for the VMS EDT editor.
- jou - EDT Journal which logs any known problems.
- ada - Ada source code.
- bas - Basic Source code.
- c - C source code.
- cob - Cobol source code.
- for - Fortran source code.
- pas - Pascal code.
- obj - The compiler creates object code before it links the source
-
- [ All examples within this text were demonstrated on an OpenVMS 6.2
- system, which is a common VMS system found connected to academic networks
- today. ]
-
- 9x - Spreading H/P in the new millenium.
- http://www2.dope.org/9x
-
- gr1p
- gr1p@b4b0.org
-