A Guide To The UniVision System

Transcription

A Guide To The
UniVision System
Version 3
Publication No.
44-00100-98A
April 1998
rd
3 Edition, April1998
It is the policy of Objectware Inc., and its subsidiaries, to improve products as
new technology, components, software and firmware become available.
Objectware Inc., and its subsidiaries, therefore, reserves the right to change
specifications without prior notice.
All features, functions, and operations described herein may not be marketed by
Objectware Inc., and its subsidiaries, in all parts of the world. Therefore, before
using this document, consult your system supplier for information that is
applicable and current.
Copyright Notice
This document contains information which is proprietary to and considered a trade
secret of Objectware Inc., and its subsidiaries. It is expressly agreed that it shall
not be reproduced in whole or part, disclosed, divulged or otherwise made
available to any third party directly or indirectly. Reproduction of this document
for any purpose is prohibited without the prior express written authorisation of
Objectware Inc.
Disclaimer
Objectware Inc., and its subsidiaries, makes no representation and no expressed
or implied warranty of any kind with the regard to the documentation for any
particular purpose. Whilst every effort has been made to ensure the accuracy of
the documentation Objectware Inc., and its subsidiaries, accepts no liability for
any losses or consequential damages arising directly or indirectly from the use of
the documentation.
Objectware Inc., and its subsidiaries, reserves the right to amend this
documentation without obligation to notify any person or organisation of any such
amendments.

1998 Objectware Inc.
! Note:
The information contained herein is correct as of 28
February 1998
th
A Guide to the UniVision System
Preface
ABOUT THIS GUIDE
Organisation of the Documentation Set
The UniVision documentation set includes the following manuals:
A Guide to the UniVision System: This guide describes the UniVision system
and explains how to use it. Designed for the applications programmer it
explains concepts and terminology essential to understanding the structure
and operation of the UniVision system.
UniVision Command Reference Guide: This guide is a general reference
source for the commands available under the UniVision system. It gives
experienced users complete information about command usage. The guide
includes reference pages for all UniVision commands organised into the
following sections: UCL stacker commands, User Account verbs, SYSPROG
verbs, connectives, modifiers, and options, correlatives and conversions,
Editor commands and PROC commands.
UniVision Database Processors Guide: This manual contains four separate
guides: one each for VISION, the PROC processor, the Editor, and Runoff. A
separate section describes each processor.
UniVision BASIC Reference Guide: This guide is a reference for the BASIC
language, the application development tool under UniVision. Designed for
the experienced programmer it covers all BASIC statements and functions,
listed alphabetically.
UniVision System Administration Guide: This guide covers all tasks normally
performed by the UniVision system administrator. It includes such things as
system start-up and shutdown, creating and deleting accounts, performing
day-to-day management and backing up and restoring the system. Included
with the UniVision System Administration Guide is a separately bound
handbook of UniVision Operating Procedures for system operators.
Preface
xi
Documentation Relationship
Advanced Users,
Developers
UniVision Database Processors Guide
VISION Reference Guide
PROC Reference Guide
Editor Reference Guide
Runoff Reference Guide
UniVision BASIC Reference Guide
Administrators
UniVision System Administration Guide
All Users
UniVision Command Reference Guide
Important Note
UniVision is an application that resides on a base-operating environment such as
UNIX SVR4, AIX, Windows NT etc.
Organisation of this Guide
A Guide to the UniVision System comprises the following sections:
Section 1, System Overview, provides an introduction to the UniVision
system. It discusses the hardware components that make up the system as
well as the system software, and introduces some fundamental database
concepts that are unique to the system.
Section 2, Users Accounts, describes the structure and contents of user
accounts. Topics covered are how to log on and off the system, how to enter
commands using the UniVision Control Language (UCL), and how to use the
UCL Stacker. In addition it describes the contents of an account's Master
Dictionary.
Section 3, Creating a Database, shows how to design and create a simple
database made up of a single file. It explains how to create files, how to
define entries in the file dictionary, and how to enter data.
Section 4, Database Architecture, explains the UniVision file hierarchy in
detail. It describes the structure of dictionary items; Account Definition items,
Verb Definition items, File Definition items, and Attribute Definition items.
The section concludes with an explanation of the hierarchical structure of
items (that is, their division into attributes, values and sub-values), and a brief
introduction to correlatives and conversions.
xii
Section 5, The UniVision Database Management System, describes the
fundamental structure of the UniVision database management system. Among
the topics covered are methods of file access, and management of peripheral
devices.
Section 6, The UniVision Control Language, describes the user's interactive
working environment in detail. It explains how to log on and off the system,
how to set communications line characteristics and user process
characteristics, how to us UCL commands, and how to use the UCL Stacker.
Topics introduced in Section 2 and covered in more detail in this Section.
Section 7, File Management, provides an overview of how to manage files on
the UniVision system. Topics covered are: creating and deleting files,
copying file items, creating Q-pointers to files in other accounts, protecting
your files, resizing files for retrieval efficiency, and backing up and restoring
files.
Section 8, Account Management, discusses the SYSPROG account, how you
create and delete accounts, the SYSTEM Dictionary and its contents, and the
ERRMSG file.
Section 9, The Spooler, introduces the system process that manages printing
operations for the UniVision system. It explains how the spooler works and
describes the commands used to do such things as change the default printer
assignment, cancel a print job and capture output in Spooler hold files.
Section 10, Using Magnetic Tape, describes the commands used for writing
and reading magnetic tapes. It contains a tutorial for new users that introduces
the fundamental commands, guiding the user step-by-step through the process
of creating a tape.
Section 11, Data Communications, describes how the UniVision system
communicates with other computer systems. It explains how to establish the
connection between two machines, and how to use that connection to initiate
a remote logon session on the other machine.
Section 12, B+Tree Files and Secondary Indexing, describes the B+Tree
files. B+Trees are dynamic structures that guide the storage mechanism to the
proper disk page through a tree like series of pointers. In addition, it explains
how to support secondary indexing.
Section 13, Database Triggers, covers an overview of Database Triggers.
Triggered procedures are UniVision BASIC subroutines that control the
behaviour of the UniVision Database environment.
rd
Section 14, External File Handling, covers access of data on 3 party file
handlers.
Section 15, Remote File Handling, covers how to set up two or more systems
to provide access across multiple UniVision environments.
Preface
xiii
Sample Files
Throughout this guide, reports and examples are based on a sample application: a
mail order publishing business. The application consists of three main files:
1.
The CUSTOMERS file, which contains the names, addresses, and phone
numbers of individual customers.
2.
The ORDERS file, which contains information about book orders, including
dates and sale amounts.
3.
The BOOK-CATALOG file, which contains titles, prices, and other
information about the mail-order business's inventory.
Syntax Notation
The following conventions indicate command line syntax throughout the
documentation set.
Convention
Usage
BOLD CAPS
You must type anything shown in upper-case bold
characters exactly as shown.
italics
Anything shown in italics is variable information that
the user provides a specific value.
()
You must type parentheses. It is usually sufficient to
type only the first parenthesis; the second is optional.
[]
Anything shown enclosed in brackets is optional. You
do not type the brackets themselves.
|
A vertical bar separating two or more elements
indicates that you can type any one of the elements.
{}
Two or more elements enclosed in braces and
separated by a bar, indicate you must type one of the
elements.
You must enter all punctuation marks included in syntax format lines (for
example, commas, parentheses, angle brackets, underscores, and hyphens) unless
otherwise indicated. You do not type the brackets.
In the following syntax example:
LIST [DICT] filename [WITH[EVERY|EACH] attribute-name
value-list][(P)]
xiv
the only two elements of the line that you must enter are 'LIST' and 'filename'.
You must enter 'LIST' exactly as shown. 'filename' is a variable; you can enter the
name of any accessible file. 'attribute-name' and 'value-list' are also variables that
the user supplies. The vertical bar indicates that you can enter either 'EVERY' or
'EACH'; the brackets indicate that both of these keywords are optional. If you
enter the 'P' option, you must enclose it in parentheses.
When variables supplied by the user are two or more words long, hyphens, instead
of blank spaces separate the words indicate that you only require one element. For
example, in the command:
LIST filename item-list
the word filename indicates a single element, and the words item and list joined by
a hyphen likewise indicate a single element.
Notation in Examples
Screen examples use the following conventions:
Convention
Usage
BOLD
Anything the user types as input.
PLAIN
Any output displayed by the system (prompts,
responses to user input, etc.).
<RETURN>
Indicates that you must press the RETURN key.
<CTRL-char >
Indicates that you should type a control character. To
enter a control character, simultaneously hold down
the CONTROL (CTRL) key and press the specified
character.
You enter most commands by typing the command line at one of the prompts and
pressing the RETURN key. This is true whether you are entering a one-letter
Editor command or a lengthy VISION statement. Therefore, in examples the
RETURN key symbol (<RETURN>) only appears in cases where it is necessary
for clarity.
! Note:
Preface
This symbol indicates an important note or caution.
xv
Section 1
SYSTEM OVERVIEW
UniVision allows multiple users to work interactively on a computer, performing
a variety of tasks that involve access to a central database. The database organises
information about a business, such as employee salary, parts inventory, customer
orders, product manufacturing, and accounting. One major task performed by
UniVision is generating reports that organise and arrange the data stored in the
database into useful information. A business might generate reports that show the
volume of sales or the size of current inventory. Normally, you perform tasks such
as report generation under the control of an application program that makes the
underlying facilities of the system available in a structured, useful manner.
The key insight incorporated into UniVision is that businesses use a computer to
organise information. All the facilities of the computer system are designed
around how the UniVision system organises data.
This section describes the way in which UniVision organises data, UniVision as a
whole, how it manages the computer system, and what facilities it provides for
users.
If you prefer to use the system right away, skip to the section entitled User
Accounts for a more 'hands-on' approach to learning the system. You might want
to return to this section at a later date to get a thorough overview of how
UniVision works.
Organising Information
UniVision is a database model for the storage and retrieval of data. This model
makes UniVision ideal for describing the kinds of data managed in a business
application.
A UniVision database is a collection of files. A file is a collection of related data.
UniVision uses dictionaries to define the relationships among files and to identify
the data they contain. A dictionary is itself a file.
System Overview
1-1
The UniVision file system comprises four levels:
•
SYSTEM Dictionary level
•
Master Dictionary level
•
file dictionary level
•
data file level
The following figure illustrates the hierarchical structure of the UniVision file
system. The following description begins at the top of the hierarchy and moves
down it.
System
Level
SYSTEM
DICTIONARY
MASTER
DICTIONARY
DICTIONARY
DATA
Master
Dictionary
Level
MASTER
DICTIONARY
File
Dictionary
Level
DICTIONARY
DATA
Data
File
Level
DATA
Figure 1-1
UniVision organises its files hierarchically
Each system has a single SYSTEM Dictionary used to store information gathered
and needed system-wide. This includes information on user accounts, system
usage, and security. Typically only the system administrator accesses the
SYSTEM Dictionary through the SYSPROG account.
1-2
A Master Dictionary represents the account-level. An account is a user's place on
the system, just as an employee works in a particular office. Each account has its
own Master Dictionary that you can tailor to the needs of the users of that account.
All the files and verbs that are available to an account have entries in the Master
Dictionary.
A file dictionary can point to one or more data-level files. The file dictionary and
the data file are distinct sets of data stored in separate files. However, logically
you can think of it as a single data file comprising a dictionary portion and a data
portion. Each data-level file is associated with a file dictionary. The dictionary
defines the format of the data files associated with it. The system stores the actual
data that appears in a report in the data file.
When you use the name of a file in a command, the system looks up the filename
in the Master Dictionary of that account and follows a pointer to the file's
dictionary. This dictionary, in turn, contains a pointer that points to the data file.
Structure of Data
A UniVision file contains any number of variable length items. An item is
equivalent to a record in standard data processing terminology. For instance, in a
file containing information about employees, each employee would be described
in a single item. In addition, a dictionary consists of items, but to prevent
confusion we sometimes refer to dictionary items as entries or descriptors.
Figure 1-2 illustrates the elements of an item. An item consists of any number of
attributes, which are basically the equivalent of fields. An attribute is a container
of data that can hold a single value or multiple values. For instance, the attribute
LASTNAME holds an employee's last name. The value of this attribute varies
from item to item; it might be 'Jones' or 'Smith'. The attribute PHONE might hold
more than one value for each item, for instance, the person's work number and
home number. Values in turn can contain any number of sub-values. Attributes,
values, and sub-values are all of variable length.
System Overview
1-3
Attributes
Item
1
2
3
4
Value
Value
5
Value
Sub- Values
Multiple Values
Figure 1-2
The elements of an item
You must assign a unique item ID or key to each item. The system uses this key to
access the item in the file. For instance, you might use an employee’s Social
Security number as an Item ID.
To programmers, a file is a collection of individually accessed items. Each item is
a string containing various delimiter characters to indicate attributes, values, and
sub-values.
UniVision
UniVision is, in fact, an application that resides on a base-operating environment
such as UNIX SVR4, AIX, Windows NT, etc.
System Software
You can define the functions of the system software in terms of the facilities it has
to manage. In the following section, we look at how the UniVision system
manages:
1-4
•
Users
•
Files
Managing Users
Perhaps UniVision's biggest responsibility is to manage the work performed by
users. Each user working at a terminal is connected, by cable, to one of the
communications ports on the system. Each port is linked to a user process.
Generally, a user process is a structure representing the user's activity on the
system.
Initially all user processes are set to use the Logon processor. The Logon
processor sends a message to the user's screen, such as the one below.
Logon Please:
The job of the Logon processor is to wait for a response to this prompt and verify
that the user belongs on the system. The user must supply the valid name of an
account and a password to log onto the system. Once the system has verified the
user's response, it gives them access to an account. All the files and programs that
the user needs are available to this account.
The UniVision Control Language (UCL) processor displays a prompt (>) on the
user's screen. When the user enters a command line or statement, the UCL
processor determines which system processor the user intends to use and executes
the program. The system processor communicates with the user process and the
communications line associated with it. Perhaps it prompts for additional input or
sends output to the screen. On completion, control of the user process returns to
UCL.
There are a number of processors in UniVision. This guide describes most of
them. Table 1-1 contains a list of several UniVision system processors together
with a brief description of their use.
System Overview
1-5
Processor
Description
VISION
A database language processor that accepts English-like
query statements and generates formatted reports.
BASIC
An extended version of Dartmouth BASIC programming
language, that enables a program to be compiled and
executed.
ED
A line-oriented editor for editing programs and files. In
addition, UniVision supports a full screen text editor, DE.
UCL
The UniVision Control Language processor that allows a
user to invoke other processors.
PROC
A procedural language processor that interprets a series of
stored commands. Used to automate any sequence of
operations performed by entering commands at a terminal.
Table 1-1: UniVision System Processors
Process Scheduling
The base operating system handles process scheduling.
Managing Files
A UniVision file consists of one or more groups of frames. The minimum size of a
group is one frame (2048 bytes, of which 2000 is available for data). The system
references a file by its base (the frame ID of the first group). In the file dictionary,
an entry for a file keeps track of the base frame ID as well as the number of
groups of a file. The number of groups is known as the file's modulo. It represents
an area of space on the disk, known as the primary file space. The system
allocates this space when a user is creating a file and remains fixed regardless of
how the file grows or shrinks.
The system stores each item in a particular group, as illustrated below. UniVision
uses a random-access technique known as hashing to distribute items in a file. It
derives the group address of an item from the item ID.
The result of a hashing computation is the number of a particular group, from zero
to one less than the number of groups or modulo. The system adds this result to
the base frame ID of the file to come up with a specific frame ID. Once the system
locates this frame, it searches through the contents of this group sequentially
through the entire file by narrowing the search to a particular group.
1-6
An item always hashes to the same group, even if that group is full. When you
exceed the capacity of a group, the system takes the additional frames from a table
of available frames, the Overflow table, and links to that group. These frames are
referred to as the secondary file area. If you reduce the size of the group, the
system returns the frames in the secondary file area to the Overflow Table. The
system only allocates these frames as needed.
Groups are like dividers in
a file drawer, organising
items in a file
Item
Item
GROUP 2
Item
Item
GROUP 1
FILE
Figure 1-3
Each item hashes to a particular group
The penalty of allowing a group to overflow into secondary frames is that
additional disk reads are necessary in order to access items that are not in the
primary frame of the group. Therefore, reallocating a file to increase the modulo
helps to distribute items more efficiently across all groups.
In this section, we have covered the basic facilities of UniVision. In subsequent
sections you will learn more about these facilities and the commands that access
them. Before continuing on to the next section, you might review the terms
introduced in this section.
System Overview
1-7
Glossary
Account
Groups of files and verbs by a Master Dictionary (MD). A
user gains access to an account when logging on.
AMC
Attribute mark counter, or attribute number.
Attribute
Structure that contains one or more data values. It is possible
to sub-divide attributes to comprise multi-values and
multiple sub-values. An attribute is analogous to a field used
on other systems.
Attribute mark
System delimiter used to separate attributes. It is ASCII
value 254 (hexadecimal FE).
Base
Frame ID of the first group of a file, specified by Attribute 2
of a File Definition item.
CPU
Central Processing Unit
Database
Collection of logically related data organised for efficient
storage and retrieval. A database might consist of a group of
files or a single file.
Data file
Fourth-level file associated with a dictionary on the previous
level. The data file contains the raw data whereas the
dictionary defined the structure of the data.
Dictionary
File structure for defining the structure of data.
File Dictionary
File structure that points to a data file on the next level and
defines its contents. If you have not associated a file
dictionary with a data file, it points to itself.
1-8
Form Queue
Logical print queue that permits the association of a
particular form with one or more printers.
Frame
Fixed length unit of storage; 2048 bytes for UniVision
Group
Group of items whose item Ids hash to the same group
number. Initially a file consists of a set of contiguous frames
as indicates by the modulo. Individuals groups can overflow
into secondary allocation when the primary frames become
full.
Item
Piece of data in a file. Analogous to record used on other
systems.
Item ID
Key used to access any item.
Logical Tape Unit
Number that identifies a tape drive
Master Dictionary
Master file of any account on the system. It contains
definition items for all verbs, VISION keywords, Procs, and
file accessible to an account.
Modulo
Number of groups allocated for a file; it represents an area of
contiguous disk space.
Overflow Table
Table that keeps track of available frames that the system
can use to expand the storage of a group.
Peripheral Device
Various hardware devices connected to the computer, such
as terminal, tape drives, printers, modems, etc.
RAM
Random Access Memory – main memory of the computer
system.
Spooler
System process that handles all printer operations.
SYSTEM Dictionary
Master file of the UniVision system at the top of the file
hierarchy. It holds Account Definition items that define all
accounts on the system.
UCL
UniVision Control Language. The UCL processor handles
most of the user’s communication with the computer,
passing control to other system processors whenever
appropriate. In most cases control returns to UCL on
completion of other processing
User process
Part of the UniVision system that handles all user activity.
Each terminal connects to the computer via a serial port that,
in turn, links to a user process.
Value
Structural sub-division of an attribute. Attributes can
comprise one or more values.
Virtual Memory
Way of overcoming the limitations of RAM size by using the
hard disk as an extension of physical memory.
System Overview
1-9
Section 2
USER ACCOUNTS
An account is a user's place on UniVision. It controls a user's computing
environment by providing access to system resources and files. You can customise
this account for the needs of a particular user or application such that the
collection of files and processors available might differ from one account to the
next.
A user must know the name of the account, and usually a password, to be able to
log on to the account. On logging on, communication with the system is usually
via UniVision Control Language (UCL). The UCL processor interprets commands
entered at the user's terminal and initiates processing by other system processors,
such as the Editor, VISION and BASIC.
This Section covers logging on and off the system, entering a few basic
commands, and examines the contents of a user account and a sample file.
Creating an Account
On a newly installed system, there is one master account, called SYSPROG, used
by the administrator to perform system-wide tasks such as adding new user
accounts. When an administrator creates a new account, three things happen:
•
The system allocates space for the Master Dictionary of the account.
•
The system creates an Account Definition item in the SYSTEM
Dictionary.
•
The system copies all items in the NEWAC file, located in the SYSTEM
Dictionary, into the new account's Master Dictionary.
The account definition in the SYSTEM Dictionary identifies the location of an
account's Master Dictionary. It defines the security level of the account and sets
access restrictions, including passwords that prevent unauthorised users from
gaining entry to the system. In addition it can specify various options that
customise the user's computing environment.
The administrator can set up unique user IDs, enabling multiple users to use the
same account, but requiring each user to identify their own logon name and
password.
User Accounts
2-1
The Section entitled Database Architecture describes the format of Account
Definition items.
! Note:
It is assumed that the administrator has set up an account
for you and that you know the logon name and password
for the logon account. If you do not have an account, ask
your administrator to create one for you, or follow the
procedures described in the Section entitled Creating
and Deleting Accounts in the UniVision System
Administration Guide.
Logging On and Off
Logging to the UniVision Environment
Login is the process of gaining access to the UniVision environment. You must
have installed UniVision and set up the environment according to the loading
instructions.
During the initial installation of UniVision, the system allows the installer to
install the software in a different directory other than the default directory of
/home/UniVision. During installation you can specify a password that any user
must know when logging in. Check with the system administrator for the login
name and password.
If you use the default directory for UniVision, the login for UniVision is UniV.
! Note:
If you use the default directory, you must use capital U
and V and the remaining letters must be in lower-case. If
this is not so the system does not recognise you as a valid
user.
For example, a typical login is as follows:
UNIX System V Release 5.0 Version 3.0
login: UniV
Password:
! Note:
2-2
For security reasons, the operating system does not echo
the password typed by the user. Type both the login
name and password correctly, otherwise the system
denies login. In addition, under some operating system
releases with the proper option, if you have not created a
password for the login directory the system might not
prompt you for a password.
After you have completed the login process, on a UNIX based system it displays a
login banner and copyright notice. You are now at the Logon Please: prompt
where you are in the UniVision environment but have not gained access to a user
account or database. To gain access to the database you must logon.
Logging On
Logging on is the process of gaining access to the system from a terminal. The
system must be up and running, and the terminal must be connected to the system
and turned on. The following logon prompt (or similar one) should appear on the
screen:
Logon Please:
To logon, type the account name (or user ID) and press <RETURN>. Be sure to
enter the account name in upper case. If the account is password protected, the
system prompts for you to enter it. The characters do not appear on the screen as
you type the password.
It is possible to enter both the account name and password at the logon prompt.
You must follow the account name with a comma and the password, as shown
below:
Logon Please: JOHN, OVL314
! Note:
If you use this form of logon the system does not echo
the password to the screen, nor does it display the
Password prompt.
If you do not enter a valid account name and password, the system redisplays the
logon prompt for additional attempts. At some sites, after several unsuccessful
logon attempts, the system inhibits logging on for a fixed period of time, refer to
LOCKOUT in the UniVision Command Reference Guide for more detail. In
addition, the administrator might prevent users from logging on while the system
performs certain maintenance or system backup tasks. If you have any problems
logging on, contact your administrator.
Once a user has logged on, the system displays a message identifying the
UniVision software release and the current system date.
User Accounts
2-3
[]
UniVision time is
16:49:26
12 JUL 1995 []
Logon Please: JOHN, OVL314
[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]
[]
e|d|p
[]
[]
Research & Development Group
[]
[]
GCA Release 2
[]
[]
Version 4.10.6
[]
[]
Wed Jul 12 10:20:30 GMT 1995
[]
[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]
>
! Note:
The system does not echo the password to the screen.
UCL displays the greater-than symbol (>) as the system
prompt. When this prompt appears on the screen, the
user can begin entering commands.
It is possible for system suppliers and administrators to customise both the logon
prompt and the messages that appear when logging on. Therefore, it is possible
that something different from the display shown in this section to appear on the
screen. In addition, the sequence of events after logging on might differ. The
Section entitled The UniVision Control Language, describes use of a Logon
Proc to control what happens after logging on. For instance, you can use it to start
up a BASIC application so that the user never gets to the UCL prompt.
Logging Off
To end a user session, type OFF at the UCL prompt and press <RETURN>. On
logging off, the system displays a message that gives usage statistics for the
current user session and the logon prompt appears on the screen.
>OFF
[]
[]
Connect time = 0 mins.; CPU = 1 units; LPTR pages = 0
Logged off at 20:32:56 on 03 MAY 1989
[]
[]
[]
UniVision time is
[]
20:32:56
03 MAY 1989
Logon Please:
If OFF does not succeed in logging off from the system, make sure that you
entered it at the UCL prompt. For example, if you are in another processor, such
as the Editor, which uses a period (.) as the prompt character, you must exit the
Editor before you can log off.
2-4
The UniVision system has an auto-logoff feature which, when implemented by the
system administrator, logs off any user automatically after a specified duration of
inactivity. For instance, if you leave your terminal and go to lunch, you might find
that you have been logged off by the time you return. For more detail refer to
AUTO-LOGOFF in the UniVision Command Reference Guide.
Exiting the UniVision Environment
To exit the UniVision Environment at UCL you can enter OFF to logoff the user
account, followed by QUIT at the Logon Please prompt. QUIT returns the user to the
UNIX login prompt.
A one step method exists for the above. A user at UCL can enter :QUIT to logoff
the user account and return to UNIX.
Introducing the UniVision Control Language
The UniVision Control Language (UCL) is the primary interface between the user
and UniVision. It is a command processor.
st
When you enter a command line at the UCL prompt, UCL looks at the 1 word
typed, and looks up the word in the Master Dictionary. If it finds an entry, it
identifies a system processor and passes control to the processor. The system
processor interprets the rest of the command line. As shown in Figure 2-1, UCL
acts on user commands to invoke other system processors.
User Accounts
2-5
DATA/
BASIC
Editor
VISION
PROC
Spooler
UniVision System Processors
Figure 2-1
The UniVision Control Language interprets input from the user’s terminal and
passes control to other system processors
The following is a description of a few simple commands.
WHO displays two pieces of useful information: the number of the user process
associated with the terminal and the name of the account logged on. To enter
WHO, type WHO at the UCL prompt and press <RETURN>:
WHO
2 JOHN
WHO is the user's input entered at the UCL prompt. 2 JOHN is the output returned
by the command.
2 is the user process number. The system identifies each user process by a unique
number in a range from 0 to the maximum number of users supported. JOHN is the
name of the account. The user process number is independent from the account. If
you log on to a different account from the same terminal, the account name would
change, but the process number would be the same.
Many commands have optional parameters that modify the action of the verb. In
addition, WHO has an optional * parameter that allows you to see this information
for all users on the system. The following example shows a listing for all users
currently logged on to a system.
2-6
> WHO
2 JOHN
> WHO *
0 JULIE
1 FRED
2 JOHN
3 STAFF
4 WALTER
5 LINDA
6 KATIE
7 UNKNOWN
8 UNKNOWN
9 UNKNOWN
10 UNKNOWN
11 UNKNOWN
12 UNKNOWN
13 UNKNOWN
14 UNKNOWN
15 UNKNOWN
The full output produced by WHO * tells us that this system supports 16 users (015) and that only seven users are currently logged in. For instance, 'LINDA' is on
user process 5.
If you require a printout of this result, add the P option to the command line.
Enclose the option in parentheses.
> WHO * (P)
Instead of the listing appearing on the screen, a message tells the user that the
system has sent the output to a printer.
UCL Prompt
Parameter
>WHO*(P)
Option
Command
Figure 2-2
A UCL statements consists of a verb followed by optional or required parameters
and any parenthetical options
User Accounts
2-7
Entering Commands
A UCL statement consists of a verb, optional or required parameters, and options
enclosed in parentheses:
verb [parameters][(] options [)]
Figure 2-2 shows an example of these syntactical elements. You must type the
entire statement in upper-case characters. The system does not interpret the
statement until you press <RETURN>.
The verb is the action word that initiates processing. The set of optional or
required parameters is specific to the verb. For instance, COPY that copies items
in a file, takes two parameters: the name of a file followed by the name of an item.
COPY ORDERS 10118
COPY is the verb, 'ORDERS' is the name of file defined in the account, and
'10118' identifies an item in that file. When you enter this command line, the
system responds with TO:, prompting for the destination for the copy operation.
Pressing <RETURN> at this prompt causes the system to display the item on the
screen.
Parenthetical options appear at the end of a command line and are surrounded by
parentheses. You only require the left parenthesis for the system to recognise the
option.
CT ORDERS 10118 (P
You can use the P option with any of the commands described in this section to
direct the output to the printer. Options comprise a single alphabetic character or a
single number or two numbers indicating a range (n-m). You ca specify multiple
options without spaces or delimiters between them, although you can separate
options with commas. For a complete list of parenthetical options, refer to the
Section entitled Connectives, Modifiers and Options in the UniVision Command
Reference Guide.
Editing the Command Line
You can change what you typed on the command line up until the time you press
<RETURN>. Table 2-1 lists the control characters available for editing the
command line.
2-8
Character
Operation
<CTRL-H>
Backspace over and delete previous character. Same as
<BACKSPACE>.
<CTRL-W>
Backspace over and delete last word.
<CRTL-X>
Cancel and delete entire command line.
<CTRL-R>
Redisplay line. One use is during a communication session
to see if garbage characters stemming from noisy telephone
lines affect the UCL input line.
Table 2-1: Control Characters
Paging
Some commands produce more output than can fit on a single screen. Normally
the processor displays one page of output at a time and pauses. To see the next
page of output, press any key. To exit instead of seeing the next page of output,
press <CTRL-X>, which returns to the UCL prompt. This is particularly useful to
know when producing VISION reports on the terminal. If you find what you want
st
in the 1 page, you can exit and ignore the rest of the output.
You can specify the parenthetical option N (NOPAGE) on the command line to
disable paging. In other words, output to the screen is continuous.
To control the flow of output, press <CTRL-S> to halt the output and <CTRL-Q>
to resume output. (This works whether or not paging is in effect). <CTRL-S> and
<CTRL-Q> send X-OFF and X-ON signals, respectively, to the communications
line. You must enable the X-ON/X-OFF protocol for your communications line
for these control sequences to work. LIST-LINE-CHARS or LINE-PROTOCOL list
line settings for each line on the system. You can use PROTOCOL to change these
settings.
The Break Key
While a system process is running, it remains in control of the terminal. Normally
you require the system process to complete its work and return control to the UCL
level. If you press <BREAK> while a process is running, the system suspends it
and invokes debugger.
Programmers use debugger to examine the state of a program as it is executing.
UniVision has two debuggers: the system debugger, identified by an exclamation
mark (!) prompt and the BASIC debugger, identified by an asterisk (*) prompt. If
you break a program by accident, you can resume execution of the process by
typing G.
User Accounts
2-9
There are two other debugger commands that you might want to know. END
which terminates the suspended process and returns to UCL. OFF which logs you
off the system. For instance, to exit to the UCL prompt from the system debugger,
type END and press <RETURN>.
!END
>
! Note:
You should be extremely cautious in exiting a process
because it might have been updating items in a file.
Consult with your system administrator if you enter the
debugger unexpectedly.
You can enable or disable <BREAK> using DEBUG-ON and DEBUG-OFF,
respectively; the default setting is <BREAK> enabled. In addition, you can disable
it by placing B in Attribute 9 of the Account Definition item.
Introducing the UCL Stacker
A useful feature of UCL is the UCL Stacker. The UCL Stacker puts each
command entered on top of a 'stack'. You can list the contents of the stack and
review recent statements. You can recall, modify, and re-execute any statement in
the stack. You can save a series of commands as an item in a file. This can save a
lot of time when typing long VISION statements or performing a sequence of
actions such as editing, compiling, and running a program.
The system specifies UCL Stacker commands with a period (.) that precedes a
single-letter command. The section entitled The UniVision Control Language,
reviews all of the UCL Stacker commands. The following shows two most
frequently used commands:
Stacker
Command
Function
.L
List most recent statements. Can specify the number of
statements to list, default is 20.
.X
Execute last statement. Can execute any statement for stack
by supplying its number.
The following example shows .L; the output is a list of the commands executed so
far during this session.
! Note:
2-10
The most recently submitted command is at the top of
the stack.
.L
001 WHO A (P
002 WHO A
003 WHO
The default length of the stack is 20. That is, you can list up to 20 previous
commands. You can execute any command from the stack using .X.
.X3
WHO
2 JOHN
.X without an argument executes the statement on top of the stack.
The Master Dictionary
The Master Dictionary provides each account with its own view of the UniVision
system. It defines the user's vocabulary. You can customise the Master Dictionary
in a variety of ways for user preferences or to establish the 'vocabulary' needed or
a specific application. The Master Dictionary contains six types of entry, as shown
in Figure 2-3. The Section entitled Creating a Database describes the format of
the dictionary entries.
MASTER
DICTIONARY
File
Definition
Items
Attribute
Definition
Items
VISION
Keywords
PROC
Verb
Definition
Items
File
Synonym
Items
Figure 2-3
The Master Dictionary contains six types of entry
User Accounts
2-11
Verb Definition item identifies a command you can execute in this account.
File Definition item is a pointer to a database file. In the Master Dictionary,
the D-pointer supplies the location and size(modulo) of the dictionary. The
dictionary in turn contains a D-pointer that supplies the location and size of
the data file.
File Synonym item is a pointer to a File Definition item. Instead of pointing
to the location of the file, the Q-pointer is a reference to a File Definition item
in the user's account or in any other account on the system.
Attribute Definition item describes data by identifying a specific attribute of
a data file item, or it derives data by operating on existing data. It describes
how VISION should format the data. The system stores most Attribute
Definition items in the dictionary associated with the data file, but, in
addition, it searches the Master Dictionary if it cannot find the entry for an
attribute identified in a VISION statement in the file dictionary.
Proc is a series of commands interpreted by the PROC system processor.
Procs stored in the Master Dictionary can invoke Procs stored in special files,
such as UVPROCS.
VISION Keywords are syntactical elements of the VISION data retrieval
language. Keywords comprise connectives (such as AND, OR, or USING),
and modifiers (such as WITH, BY, or TOTAL).
st
When a user enters a statement, UCL expects the 1 word in the statement to be a
verb, a Proc or a UCL Stacker command. When you enter a verb, UCL looks for a
Verb Definition item in the account's Master Dictionary. This entry points to the
location of the program code actually executed. The Section entitled Database
Architecture describes the format of Verb Definition items.
If you cannot identify the verb, the system displays the following error message:
[3] Verb?
In most cases, when this message appears, the user has mistyped the statement.
The [3] preceding this message identifies this message by number in a system file
named ERRMSG.
Examining an Account
You can examine the contents of an account by looking at the Master Dictionary.
The following sections introduce a few commands that allow you to examine the
Master Dictionary.
2-12
Listing the Files
You can use LISTFILES to view a list of the files available in the account. It
generates a VISION statement that selects a set of related items, sorts them
alphabetically by name, and displays the contents of various attributes.
Generally, the LISTFILES report is too long for it to be displayed all at once on a
screen. The system pauses after displaying one page of output and waits for you to
press a key before displaying the next page.
An example of the LISTFILES report follows
>LISTFILES
PAGE 1
*** MD *** FILE DEFINING ITEMS
13 JUL 1993
MD
FILE TYPE FILE BASE........... F/MOD........
BP
CONV
CUSTOMERS
LOCKXREF
NEWAC
ORDERS-WINTER
PATCHES
PAYROLL
POINTER-FI
SAVEDFILE
SM
SN
STAT-FILE
SYSPROG-BP
SYSPROG-L
TC
TEST2
ACC
BASICLIB
DC
DC
D
D
D
D
D
D
DC
D
D
D
D
DC
DC
D
D
Q
Q
4717
4343
6762
3398
3390
8437
3467
8162
3428
8435
3512
4379
4768
3498
4724
8271
8245
ACC
BASICLIB
1
1
3
1
1
1
1
1
7
1
1
1
1
1
1
1
1
ACC
BASICLIB
You can summarise the report produced by LISTFILES as follows. The report lists
information in four columns and displays a row of data for each File Definition
st
item in the Master Dictionary. The 1 column contains the names of files. The
filename is the item ID of a File Definition item. The next three columns
correspond to the first three attributes of a File Definition item.
The column labelled FILE TYPE lists a Definition Code that identifies what kind
of item it is. A value of D indicates a D-pointer to a file located in the account.
nd
The 2 attribute, FILE BASE, of a D-pointer specifies the base frame ID used to
st
rd
locate the 1 group on disk for the file. The 3 attribute, F/MOD, specifies the
modulo of the file or the number of groups occupied by the file.
User Accounts
2-13
In the sections that follow, many examples make use of the CUSTOMERS file. It
contains basic information such as name, address, and phone number for a group
of individual customers. Find the File Definition item in the example for
CUSTOMERS; it has a base of 6762 and consists of 3 groups.
In addition, this report lists Q-pointers. Q-pointers reference files located in this
nd
and other accounts on the system. The 2 attribute of a Q-pointer identifies the
account in which the file is located. If null, you can find the file in the same
rd
account. The 3 attribute identifies the name of the file in that account. If null, the
file is the Master Dictionary. MD and M/DICT are Q-pointers that refer to the
Master Dictionary itself.
Enter LISTFILES at the UCL prompt to display a listing of the files defined in
your account. In addition, you can try LISTVERBS that displays a listing of the
verbs defined in your account. It shows the first five attributes of Verb Definition
items in the Master Dictionary. The output from this report is less meaningful to a
new user; you will understand it better when we look at the format of Verb
Definition items in the Section entitled The UniVision Control Language.
Listing the Contents of Items
You can use CT (Copy to Terminal) to see a copy of one or more items from any
file. (It is a Proc that invokes the COPY processor.) CT is a very useful command
for looking at items in the Master Dictionary or in any file. You can view the item
on your screen or send it to the printer to get a hard copy.
You must specify the name of a file and a valid item ID in that file. You can
specify multiple item IDs by separating each one with a space.
CT [DICT] filename item-list [(options)]
Use CT to examine a File Definition item in the Master Dictionary, a File
Definition item in a file dictionary, and finally a data item in a data file. These
examples using the sample file CUSTOMERS illustrate the multi-level
relationship among the Master Dictionary, the file dictionary and the data file
shown in Figure 2-4
2-14
CUSTOMERS
001 D
002 11408
003 3
.
.
Master
Dictionary
CUSTOMERS
001 D
002 11411
003 3
.
.
File
Dictionary
JBOHA5422
001 JOHN
002 BOHANNON
003 126 TREMONT ST
.
.
Data File
Figure 2-4
The Master Dictionary contains a pointer to the dictionary that contains a pointer
to the data file
The following example lists the File Definition item for CUSTOMERS in the
Master Dictionary
> CT MD CUSTOMERS
CUSTOMERS
001
002
003
004
005
006
007
008
009
010
D
11408
3
L
10
>
This D-pointer file identifies the location of the dictionary for the CUSTOMERS
file A portion of this dictionary appeared in the previous LISTFILES report.
The CUSTOMERS file dictionary contains an item named 'CUSTOMERS' that is
the pointer to the data file. The next example shows that item:
User Accounts
2-15
>CT DICT CUSTOMERS CUSTOMERS
001
002
003
004
005
006
007
008
009
010
CUSTOMERS
D
11411
3
L
12
>
The DICT modifier specifies the dictionary of a data file. CUSTOMERS appears
as both the filename and the item ID in the command. This item is virtually
identical to the File Definition item in the Master Dictionary, except for the
specification of a different base. The base frame ID of 11408 points to the location
of the data file.
rd
The 3 example lists an item from the CUSTOMERS data file.
>CT CUSTOMERS AJOHN5396
001
002
003
004
005
006
007
008
AJOHN5396
ANNE
JOHNSON
760 JEFFERSON STREET
LOUISVILLE
KY
6069034566
99475
192-83-7465
AJOHN5396 is the item ID of this item, which has eight attributes. This item
contains data; it does not contain any information about what the data means or
how it should appear in reports. The file dictionary contains Attribute Definition
items corresponding to each attribute in the data file item.
st
Look at the Attribute Definition item for the 1 attribute in a CUSTOMERS data
file item. The item ID is FIRST-NAME.
2-16
>CT DICT CUSTOMERS FIRST-NAME
001
002
003
004
005
006
007
008
009
010
FIRST-NAME
A
1
First Name
L
10
>
A identifies the item as an Attribute Definition item. 1 references the position of
the attribute in the data file item. First Name is a column heading used in reports. In
addition, the entry defines that data should be left-justified (L), in a column ten
characters wide.
The VISION processor uses the dictionary to generate listings of data file items,
as shown in the next section. A VISION report is a much more useful way of
presenting data.
Generating VISION Reports
VISION is a query language processor put to many uses in the UniVision system.
Its simple, English-like statements produce formatted reports for the printer or
screen. In this section, several examples of VISION reports demonstrate the
relationship between the dictionary and the data file. The UniVision Database
Processors Guide explains VISION in full.
LIST is a VISION verb that produces listings of items in a report format. The
simplest statement consists of LIST followed by the name of a file. The following
is a report from the CUSTOMERS file:
User Accounts
2-17
>LIST CUSTOMERS FIRST-NAME LAST-NAME CITY STATE
PAGE 1
12:05:42
CUSTOMERS... First Name Last Name.
City........
State
HJENK7127
JBOHA5422
JBROW6749
JBUCK6488
BLEAR6803
JMASO6378
AORLA5993
SPIRS5289
MASHX5777
AEDWA5224
JPEER5993
RPIER5539
AJOHN5396
HJOHN7265
HHIGG6849
DEDGE6635
AMEAD5619
BLAMP6196
INDIANAPOLIS
BOSTON
BOSTON
LINCOLN
BOSTON
LINCOLN
VENICE
WINSTON
INDIANAPOLIS
SUDBURY
LOS ALTOS
RIDGEWOOD
LOUISVILLE
OMAHA
OMAHA
MIAMI
SUDBURY
BOSTON
IN
MA
MA
IN
MA
IN
CA
NC
IN
MA
CA
NJ
KY
NB
NB
FL
MA
MA
HAROLD
JOHN
JAMES
JULIE
BILL
JULIA
AMY
SANDRA
MARY
ANTHONY
JAN
RICK
ANNE
HENRY
HENRY
DAVID
ANDREW
BOB
JENKINS
BOHANNON
BROWN
BUCKLER
LEARY
MASON
ORLANDO
PIRS
ASH
EDWARDS
PEERCE
PIERCE
JOHNSON
JOHNSON
HIGGINS
EDGECOMB
MEADE
LAMPSON
02 AUG 1994
18 ITEMS LISTED
The report lists information in five columns with a row for each data item in the
st
CUSTOMERS file. The 1 column lists item IDs. The remaining columns display
the contents of several attributes. An Attribute Definition item in the dictionary
describes each attribute telling VISION how to display the data. You use the item
ID of an Attribute Definition item to refer to the data. For instance, the
CUSTOMERS dictionary contains Attribute Definition items name FIRSTNAME, LAST-NAME, CITY, and STATE. You can specify the names of the
attributes in a VISION statement to override the default display format. The
following statement:
>LIST CUSTOMERS LAST-NAME FIRST-NAME
produces a report listing the item ID followed by the last name and first name of
each customer.
Listing the Contents of a Dictionary
You can use LISTDICT to view a report that lists the Attribute Definition items in
a dictionary. If you do not specify a filename, the system displays a report listing
the Master Dictionary.
Using this command to list the Master Dictionary produces a long report
containing many pages. To break out of this report after viewing several pages and
exit to UCL, press <CTRL-X>.
2-18
The following command produces a listing of the dictionary for the
CUSTOMERS file.
> LISTDICT CUSTOMERS
st
The following screen shows the 1 page of the output.
PAGE 1
12:20:15 02 AUG 1994
CUSTOMERS : FULLNAME
CODE S
A/AMC 0
S/NAME FULL NAME
CORRELATIVES C;2,1
TP L
MAX 20
CUSTOMERS : FIRST-NAME
CODE A
A/AMC 1
S/NAME First Name
TP L
MAX 10
CUSTOMERS : FNAME
CODE A
A/AMC 1
S/NAME First Name
TP L
MAX 10
In the file dictionary, FIRST-NAME and FNAME are the item IDs of Attribute
st
Definition items that refer to the 1 attribute in the data item.
FULL-NAME is an entry that defines a correlative that concatenates data found in
st
nd
the 1 and 2 attribute in reverse order. In other words, it derives its value by
processing data.
The following Section describes the format of Attribute Definition items as you
create a simple database file.
User Accounts
2-19
Section 3
CREATING A DATABASE
A database is the foundation of a UniVision application. It provides a way to
organise and use business data in a logical and efficient manner. Once a database
exists, you can use VISION to generate reports that extract information for end
users. Application developers can write custom programs in the BASIC language
that provides the end-user with an integrated, task-oriented environment. Using
menus, users can perform a variety of database management tasks, such as
selecting reports, adding new items to the database, or updating existing items.
It is possible to base an application on one or more files, each one containing a
logical grouping of data. These files might be available in any or all accounts on
the system. The term 'database' refers both to an individual file and to all of these
files collectively associated with an application.
This section describes the design and creation of a simple database comprising a
single file. This process comprises the following steps:
•
Design the database.
•
Create one or more files.
•
Define entries in the file dictionary.
•
Create data.
Designing a Database
You can create a simple database such as one used to generate a personal phone
directory without considering the size of the database or its structure. However, to
set up a database for use in a business application a developer should follow the
steps outlined in this section. It is essential that careful thought be given to
database design. The design should accomplish three objectives:
•
To organise data generated by a business so that you can access and
manipulate it easily.
•
To establish relationships among all the pieces of data.
•
To determine what information is useful for display in reports.
Creating a Database
3-1
Before structuring the database, you should consider the following points:
•
Decide what output you must produce for reports.
•
Determine what data elements exist and their names and relationships.
There is the flexibility to change the database after you have set it up. However,
you should establish the structure of the database before creating it. The most
important thing is to establish the sequence of attributes, values, and sub-values in
a data file item. It is cumbersome and time-consuming to change these
relationships once you have defined them.
Use the following check-list to design a database:
•
Decide how many files you need and assign a unique name to each one.
•
Identify what set of data constitutes an item (record) in each file.
•
Identify one piece of data unique to each item and is it possible to use
this as the item ID or key.
•
Assign a name unique and descriptive to each attribute. Determine if you
require a more descriptive name for identification in reports.
•
Determine the maximum column width needed to display each attribute
in a VISION report, and decide whether data should be left- or rightjustified in this column.
It is possible to see that the dictionary’s Attribute Definition items reflect most of
these decisions.
The CUSTOMERS File
This section examines another sample file, the CUSTOMERS file, containing the
names and addresses of customers for a mail-order business. The previous Section
describes reports generated from this file.
The system stores the person’s first and last names, street address, city, state, and
zipcode for each customer. In addition, the system stores the person’s phone
number. Each of these pieces of data in an attribute of a data file item must be
unique to the customer.
Creating a File
CREATE-FILE creates a file. Typically, you use it to create both the dictionary
and the data file at the same time. CREATE-FILE requires you to specify the name
of the file and physical disk space allocated for it. You specify the amount of
space as the file's modulo and base it on an estimate of the size and expected
growth of the database.
3-2
Selecting a Filename
A filename identifies the database file in the account. The following are a few
rules to remember when assigning a filename:
•
You cannot use the following characters in a filename: a space, comma,
semi-colon, and a single or double quote mark.
•
Parentheses, apostrophes, and quotes, while legal are not recommended.
The name of a file should indicate something about the contents of the database. It
must be unique in the account. In addition, you can use Q-pointers to create
shorter synonyms for a file. For instance, a file named 'CUSTOMER.MASTER'
might have a synonym name 'CM'.
Selecting a Modulo
Before creating a file it is necessary to estimate the amount of space needed for
the file. The modulo specifies the number of groups allocated for a file.
In choosing a modulo, estimate the average size of an item and the number of
items in a file. If the average item size is less than 2000 bytes, you can use the
following chart to estimate the modulo of a file. The right-hand column gives an
estimate for a sample file. Round off calculations to the next largest integer.
A.
Average Size of Item
100
B.
Number of Items
50
C.
Multiply A and B
5000
D.
Group Size (2000)
2000
E.
Divide C By D
3
F.
Choose prime number Modulo
3
The modulo of a file should be a prime number for an even distribution of items.
It should never be a multiple of 2 or 5. CREATE-FILE ensures that the modulo
entered is not a multiple of two, by adding one to get an odd-numbered modulo.
For instance, if you enter a modulo of 2, CREATE-FILE specifies a modulo of 3.
Some databases are static by design, that is, they contain a fixed amount of
information that does not change often or increase significantly. Others are
dynamic in that they increase in size over time. When estimating the size of a file,
you should know whether to allow for the dynamic growth of the database. It is
possible to calculate the amount of space available in each group for expansion.
Use the following chart for this test.
Creating a Database
3-3
G.
H.
I.
J.
Divide B by F
Group Size
16
Multiple A by G
Characters Used
1600
Subtract H from D
Available Group Space
400
Divide I by A
Number of New Items
4
Using the sample figures, this tells us that with a modulo of 3, the average number
of items per group is 16 and that there is sufficient space for 4 more items per
group. This is an indication that the file can expand by 12 items or approximately
20 per cent over the estimate before requiring additional storage space. However,
this is only an estimate of actual usage; the hashing scheme does not guarantee
even distribution across all groups.
The Section entitled File Management gives additional information on creating
and deleting file, and on monitoring the size and efficiency of files.
Using CREATE-FILE
To use CREATE-FILE, you must specify the following information on the
command line:
•
the name of the file
•
the modulo of the dictionary
•
the modulo of the data file
The name specified for the file must be unique in the account.
In this example CREATE-FILE, creates a database file called PAYROLL. The
modulo specified for the dictionary is 3 and for the data file is 43.
>CREATE-FILE PAYROLL 3 43
[417] UniVision File 'PAYROLL' Created; Base = 6762; Modulo = 3
[417] UniVision File 'PAYROLL' Created; Base = 6765; Modulo = 43
CREATE-FILE allocates disk space for the PAYROLL file and creates D-pointers
in two different dictionaries. It creates an entry for the PAYROLL dictionary in
the Master Dictionary, and an entry for the PAYROLL data file in the PAYROLL
dictionary.
3-4
When you create a database as shown in the previous example, the dictionary and
the data file are in a one-to-one relationship. The dictionary and the data file have
the same name. When multiple data files share a dictionary, only one data file can
have the same name as the dictionary.
If an existing database has a single data file, you can use CREATE-FILE to create
additional data files. For example:
>CREATE-FILE DATA PAYROLL,PAYROLL.LASTYEAR 43
[417] UniVision File 'PAYROLL.LASTYEAR' Created; Base = 6873 Modulo = 43
The DATA modifier specifies that you only want to create the data file, the
dictionary PAYROLL MUST exist already.
When setting up a shared dictionary, you can create the dictionary before or at the
st
same time as the 1 data file. The following example creates the dictionary file
'INVOICES with a modulo of 3.
>CREATE-FILE DICT INVOICES 3
[417] UniVision File 'INVOICES' Created; Base = 6648, Modulo = 3
Then you can create each data file. You must supply the name of the dictionary
followed by a comma and the name of the date file.
>CREATE-FILE DATA INVOICES,OCTOBER 3
[417] UniVision File 'OCTOBER' Created; Base = 6749, Modulo = 3
>CREATE-FILE DATA INVOICES,SEPTEMBER 3
[417] UniVision File 'SEPTEMBER' Created; Base = 6752, Modulo = 3
As a result of these commands, the INVOICES dictionary has two D-pointers to
identify the data file: 'OCTOBER' and 'SEPTEMBER'. It is possible to set up
additional data files at any time as needed.
You could have combined the first two commands in the previous example to
create the dictionary and one of the data files at the same time.
>CREATE-FILE INVOICES,OCTOBER 3 3
[417] UniVision File 'INVOICES' Created; Base = 11898, Modulo = 3
[417] UniVision File 'OCTOBER' Created; Base = 11901, Modulo = 3
! Note:
There is no data file named 'INVOICES'; however, you
could create it explicitly.
Creating a Database
3-5
Creating Dictionary Entries
A item in the dictionary has the following format:
Item ID
Name
D/CODE
A/AMC
A/NAME
A/AMC
Definition Code
Attribute Number
Column Heading
Structure
1
2
3
4
V/CONV
V/CORR
V/TYP
V/MAX
Not Used
Not Used
Conversion Code
Correlative Code
Type
Column Width
5
6
7
8
9
10
Line
Description
Enter identifier
Attribute Mark Count
Report heading or tag
Controlling and Dependent
attributes
Conversion specification
Correlative specification
Justification and wrap
Width of display field
You only require the Definition Code and attribute number.
! Note:
Lines 5 and 6 are empty. The next section examines each
specification.
You can create dictionary items using the line editor (EDIT or ED) or the full
screen editor (DOC-EDIT or DE). If you use the line editor to create entries, you
cannot insert empty lines, in insert mode, by pressing <RETURN>. Pressing
<RETURN> on an empty line exits insert mode; the screen editor uses <ESC> to
exit insert mode and avoids this problem. There are two ways around it: one is to
enter a single character on any line you want to be empty and later use R to find
that character and replace it. Perhaps the best way is to use <CTRL-^> to insert
attribute marks for each empty line. The following example demonstrates this
method to create a dictionary entry named 'CUST-ID'.
3-6
>ED DICT ORDERS CUSTOMERS-ID
NEW ITEM
.I
001+A
002+1
003+ Customer ID^^^^
004+ML(#-####-####)^
005+L
006+12
007<<RETURN>>
.F
TOP
.P
001 A
002 1
003 Customer ID
004
005
006
007 ML(#-####-####)
008
009 L
010 12
.FI
'CUSTOMER-ID' FILED
When the system updates and displays the editor buffer, the new listing shows that
the system has interpreted the attribute marks as new lines.
The subsequent sections look at each of the dictionary specifications in more
detail.
Naming the Attribute Definition Item
Each entry in the dictionary requires a unique name. This name is the item ID of
the Attribute Definition item. The name usually serves as a logical reference to the
data contained in an attribute in the data file item.
For instance, if the first attribute of an item contains a customer's first name, the
name of the Attribute Definition item might be FIRST-NAME. Since you often
use these names in VISION commands, you should ensure they are reasonably
descriptive.
Identifying the Entry (Line1)
st
A Definition code or D/CODE specified on the 1 line identifies each entry in a
dictionary.
A
Creating a Database
Attribute Definition item. It references the contents of an
attribute in the data file.
3-7
S
Synonym Definition item. Usually, you create Attribute
synonyms to define default output specifications for
VISION.
I
phrase definition. You can use phrases to store parts of a
VISION command.
X
place holder that maintains the sequence of default output
attributes but produces no output.
In addition, you find D-pointers in the dictionary. You create them using
CREATE-FILE and users should not modify them.
Attribute Number (Line 2)
The attribute number or A/AMC is an integer specifying the sequential position of
an attribute in a data file item. For example, LAST-NAME has an attribute
nd
number of 2, identifying it as the 2 attribute in a CUSTOMERS data file item.
Table 3-1 summarises the attribute numbers of the items in the CUSTOMERS
dictionary.
Attribute
FIRST-NAME
LAST-NAME
STREET
CITY
STATE
PHONE
ZIP
Attribute Number
1
2
3
4
5
6
7
Table 3-1: Attribute Positions in the CUSTOMERS File
An attribute number of 0 (zero) refers to the item IDs in the data file. When
creating synonyms, you can specify an AMC of 0, the AMC of a referenced
attribute, or any number greater than the last attribute number specified. You can
assign an arbitrarily high attribute number to any entry so that you can reference it
in correlative expressions.
An attribute number of '9998' or '9999' has special meaning. In a VISION report,
an entry with an attribute number of 9998 displays a running count of items in the
report; 9999 displays the size of each item in bytes.
3-8
Column Heading (Line 3)
This parameter defines the column heading or S/NAME that appears when you
include the attribute in a VISION report. For example, the definition of the
column heading for LAST-NAME in initial caps and does not include a hyphen:
Last Name
If you are not specifying a column heading, the system uses the item ID of the
Attribute Definition item.
In a columnar report, the column heading appears at the top of a column,
identifying its contents. If you do not specify it, the system uses the name of the
attribute. If you specify a backslash (\), the system does not output a heading. To
specify a multi-line heading, use <CTRL-]> to indicate a line break.
Associating Multi-Valued Attributes (Line 4)
You use the structure specification (S/AMC) to define an association between
multiple values of two or more attributes. When you create an association, each
value in the Controlling attribute corresponds to a value in each of the Dependent
attributes. You can print each set of related values as a single line in a VISION
report.
The C and D codes specify a Controlling or Dependent association, respectively.
A C structure code links a Controlling attribute to one or more Dependent
attributes. A D structure code links a Dependent attribute to a single Controlling
attribute. The CUSTOMERS file does not have multi-valued attributes.
Conversion (Line 7)
A conversion is an expression applied to data just before the data appears in a
report. For example, a conversion code could format dollar amounts to insert a
decimal point and a dollar sign ($). This means that you do not have to store these
characters with the amount. The following section describes correlatives.
Correlative (Line 8)
A correlative is an expression specifying arithmetic and other types of preprocessing performed on data before processing it in any other way. It derives its
value by processing stored data. The previous section describes conversions.
Creating a Database
3-9
Justification (Line 9)
The justification specification (V/TYP) determines the alignment of columnar
data in reports, as follows:
L
Left-justified (generally the case for alphabetic data). If data
exceeds the length defined by the maximum column width, it
wraps to the next line, beginning at the first character over
the maximum length.
R
Right-justified (generally the case for numeric data).
T
Text left-justified. You use this type of justification for
textual data. If data exceeds the length defined by the
maximum column width, it wraps to the next line, starting at
a blank space.
In addition, justification affects the way in which the system shows sorted data. If
left-justified, the system sorts data from left to right. If right-justified, the system
sorts data numerically. For example, given the data '10', '9', and '90' the following
sorting occurs:
Right Justified
Left -Justified
10
9
9
10
90
90
Column Width (Line 10)
The Column Width specification (V/MAX) specifies the maximum width of the
display field in characters. Data exceeding this specification wraps on the next
line depending on V/TYP specification.
! Note:
This is an output specification and does not affect the
storage of data
The column width specification is particularly important because the sum of the
display width of specified attributes when compared with the line length of the
screen or printer determines whether the system prints a report in columns or
vertically.
You can create synonyms to specify alternative display formats. For instance, an
attribute containing a parts description might require a 40-character display field;
this might be too wide to include with either information in a columnar report.
You might define a synonym that differs from the Attribute Definition only in that
it specifies a smaller display width.
3-10
If the width of the column heading exceeds the column width specification, the
display field is the width of the column heading. If the length of the column
heading is less than the display field, the system pads the column heading with
dots (.).
Creating Data Items
The CUSOMERS Dictionary
Table 3-2 shows the contents o f th e Attribute Definition items in the
CUSTOMERS dictionary.
Item-ID
FIRST-NAME
LAST-NAME
STREET
CITY
STATR
PHONE
D/CODE
A
A
A
A
A
A
A/AMC
1
2
3
4
5
6
S/NAME
First Name
Last Name
Street
City
State
Phone
V/CONV
ML(######-####
####)
V/CORR
V/TYP
L
L
L
L
L
R
V/MAX
7
12
20
10
2
17
Table 3-2: CUSTOMER Attribute Definition Items
The Attribute Definition items shown in Table 3-2 describe a data file item format
consisting of six attributes. The attribute number (A/AMC) references the
sequential location of attributes in the data file item.
You have already seen the CUSTOMERS dictionary describing the format of
items in the CUSTOMERS data file been seen. Examine the following item from
the CUSTOMERS data file.
AEDWA5224
001 ANTON
002 EDWARDS
003 51 BLAIR AVENUE
004 SUDBURY
005 MA
006 6178897764 223
The item ID of this item is AEDWA5224. The CUSTOMERS file uses an
alphanumeric 9-character item ID constructed when you create the item. The
system builds it from the first letter of the customer's first name, the first four
letters of the last name, and an integer representing the date, as stored in internal
format, when the system created the item. For example, the data item for a
customer name Amy Orlando has the following item ID:
Creating a Database
3-11
ORLA5993
5993 is the date in internal format; if you converted the date to a normal date
format it would be 28 MAY 1984. The applications program constructs item IDs
such as these when you add a new customer to the database.
Each line in the data file item is a separate attribute. Attribute 1 contains the first
name, defines by the Attribute Definition item FIRST-NAME in the
CUSTOMERS dictionary. Attribute 2 contains the last name, defined by the
Attribute Definition item LAST-NAME, and so on.
Assigning Item IDs
The item ID allows the system to locate the specific item of a customer. The item
ID is a piece of data that must be unique for each customer in the file. For
instance, a person's last name is not a unique identifier. For that reason, you often
use sequential numeric item IDs to ensure that the ID is unique. Another benefit of
numeric IDs is more even distribution of items across groups. However, there is
nothing to prevent you from using alphanumeric keys. You should not base a key
on information that is likely to change.
When you have defined the structure of the database in the dictionary, you can
create items in the data file.
You can create a simple database containing a small amount of data using the
Editor. The Editor, of course, does not supply prompts or validate input. You
should take care to input the data in the correct order as defined in the dictionary.
The following table lists the key sequences for entering system delimiter
characters.
Mark
Input in Editor
Attribute
<RETURN> or <CTRL-^>
Value
<CTRL-]>
Sub-Value
<CTRL-\>
You could write a Proc to automate data entry via the Editor, prompting for the
data and submitting a series of Editor commands to create a new item and insert
multiple lines.
Most applications rely on custom UniVision BASIC programs for data entry. A
typical data entry program prompts a user to supply data and verifies the input
before adding a new item to the database. You might require a generalised data
entry program that you could use to create items for any database. Such a program
might use a phrase entry in the dictionary to identify the attributes that it prompts
the user to enter. If you use sequential numeric IDs, you might use an entry in the
dictionary to store the last ID number used.
3-12
Extracting Information
Before you create a database, you should note what information is useful to
retrieve and in what context you want to present it. VISION gives developers the
ability to design complex reports and forms, that the system can send to the user's
screen, printer, or tape drive. For the most part, VISION allows the developer to
forego writing programs to generate reports.
Its English-like syntax makes it suitable for direct use even by end users. Users
can query the database and display information in formatted reports on the screen
or printer.
The major component of a VISION query is an action-oriented verb, such as LIST,
SORT, or COUNT. You can use VISION verbs to:
•
Display and print lists.
•
Sort items according to complex criteria.
•
Select items you want to include in a report.
The various elements of VISION syntax can make for some long command lines.
Fortunately, there are several ways to store and execute VISION commands. You
can EXECUTE any VISION statement from a UniVision BASIC program or
submitted from a Proc.
! Note:
You cannot execute a VISION statement from within a B
correlative.
In addition, you can save a VISION statement from the UCL stack (.C) and store
it as an item in the Master Dictionary or in any dictionary or data file. You can
recall and execute this item at a later time (.R).
The syntax for referring to a data file is:
dictionary [,datafile]
st
nd
The 1 parameter is the name of the dictionary. The 2 parameter specifies the
name of the data file. The name of the dictionary and the data file can be the same,
as they normally are when they exist in a one-to-one relation. If the dictionary
points to a single data file, the name of the data file is the same as the name of the
dictionary. When multiple data files are using a shared dictionary, you must
specify which data file you want to access. To view the dictionary instead of the
data file, you must use the DICT modifier.
Creating a Database
3-13
Defining Default Output Specifications
The preceding sections described how dictionaries define the structure of the data
appearing in VISION reports. In addition, dictionaries affect the contents of these
reports by defining default output specifications. These specifications determine
the attributes displayed automatically when a VISION query does not specify the
names of any Attribute Definition items.
Unless you redefine the default explicitly, the default output for a file consists if
item IDs only. Thus, entering the following query produces a list of the item IDs
in the CUSTOMERS file:
> LIST CUSTOMERS
PAGE 1
10:33:54
01 NOV 1994
CUSTOMERS
HJENK7129
JBOHA5422
JBROW6749
JBUCK6488
BLEAR6803
JMASO6378
AORLA5993
SPIRS5289
MASHX5777
AEDWA5224
JPEER5993
RPIER5539
AJOHN5369
HJOHN7265
HHIGG6849
DEDGE6635
AMEAD5619
BLAMP6196
18 Items Listed.
>
You can define the default output specifications for the CUSTOMERS data file by
performing any of the following operations in the CUSTOMERS dictionary:
•
Defining an @ phrase
•
Creating a sequence of descriptors having consecutive numbers as their
item IDs.
A phrase is a dictionary item consisting of any parameters from a VISION query
except a verb or a filename.
3-14
If you implement all of these methods in the CUSTOMERS dictionary, the system
treats them in the preceding order. In all cases, the default output specifications
only take effect if a VISION query does not include the names of any Attribute
Definition items.
Creating an @ Phrase
Creating a phrase in the CUSTOMERS dictionary whose item ID is @ defines the
default output specifications for the report. You use these output specifications for
reports sent to the screen, or printer. For example, you might define the following
@ phrase in the CUSTOMERS dictionary:
@
001 I
002 FIRST-NAME LAST-NAME
003 CITY STATE
Creating Dictionary Items in Numeric Sequence
The dictionary contains a sequence of numeric item IDs in consecutive order
beginning with 1, the system users these items to define the default output
specifications. Each item in the sequence must contain an S code in Attribute 1.
If an Attribute Definition item in a numeric sequence contains an X instead of an
A in Attribute 1, the data is not part of the default output specifications. However,
the system includes the data for items that follow this X item in the numeric
sequence in the report.
For example, you can create the same Attribute Definition items 1-4 in the
CUSTOMERS dictionary, except that Attribute 1 of item 3 (CITY) contains an X.
In this case, the default output specifications includes the data defined only by
items 1, 2, and 4 (FIRST-NAME, LAST-NAME, and STATE).
Example: Creating a Database Application
This exercise asks you to create a simple database and uses several UniVision
system tools to build and generate useful reports.
A company has several hundred employees, each with a four-digit telephone
extension number. Create a database that contains the names of employees and
their telephone extension number. Assume that the extension number is unique for
each person. (How might you create the database if the extension number was not
unique? What if individuals had more than one extension?)
Creating a Database
3-15
Once you have constructed the database, you can use VISION statements to
extract information from the database. You need two different reports. One serves
as a phone directory: a printed listing of employees sorted alphabetically by name
and referencing the extension number. The switchboard operator generates the
other report at a terminal; it displays the extension number for a particular
employee. You need to be familiar with the VISION Reference Guide to
nd
accomplish this part of the exercise. In particular, to generate the 2 report, you
should look at selection expressions that allow selection of items that appear in a
report; as well as FIND.
The next step is to automate the generation of both reports so that users can access
st
them. You can automate the 1 report by saving the VISION statement from the
UCL stack and storing it as an item in the Master Dictionary. The Section entitles
The UniVision Control Language describes .C used to save and store commands
nd
from the stack. The 2 report is slightly more difficult to automate because the
user should be able to supply the name of the employee each time they run it. You
can generate it using a Proc that prompts for an employee's name and builds the
VISION statement. In addition, you can generate it from a UniVision BASIC
program using EXECUTE.
This exercise should help you become familiar with the application development
facilities in the UniVision system. Especially important is understanding how well
they work together to create a seamless database application for users.
3-16
Section 4
DATABASE ARCHITECTURE
A database defines logical relationships among individual elements of data. In one
sense, a database is a set of containers for data. Imagine that a person puts
something in a small box, and puts the small box in the top drawer of a bureau
located in the bedroom of a house. You might direct another person to the small
box, regardless of its contents, by having giving them the appropriate instructions.
It is possible to describe the location of the small box as a series of pointers from
one container to the next:
House > Bedroom > Bureau > Top Drawer > Small Box
This diagram depicts a chain of relationships. It is possible to follow the pointer to
reference this without really knowing what it contains. For instance, 'everything in
the top drawer' or 'everything in the bureau' indicates a set of things.
The architecture of UniVision allows you to reference a piece of data by providing
a set of files. A chain of logical relationships specifies the data contained in a
particular attribute, regardless of what it actually holds. The physical structure of
the item is the same for each file, but its logical structure or format depends on its
use.
The dictionary does more than just point to the location of data, it describes what
the data is. It establishes symbolic references that are much more in keeping with
the way people actually refer to things. For instance, a filename is a symbolic
reference to a set of data stored on disk. A dictionary item contains both the
physical and symbolic references to data in the data file item.
UniVision File System
The UniVision file system consists of four levels. At the top is the SYSTEM
Dictionary. It contains pointers to multiple Master Dictionaries (MD or M/DICT)
nd
on the 2 level, each Master Dictionary represents an account on the system. The
Master Dictionary of an account contains pointers to the account's file dictionaries
rd
th
(3 level). A file dictionary can point to one or more data files on the 4 level.
Figure 4-1 illustrates the UniVision file system.
Database Architecture
4-1
SYSTEM
DICTIONARY
MASTER
DICTIONARY
MASTER
DICTIONARY
DICTIONARY
DATA
DICTIONARY
DATA
DATA
System
Level
Master
Dictionary
Level
File
Dictionary
Level
Data
File
Level
Figure 4-1.
The organisation of the UniVision file system is on four levels
Dictionaries represent the top three levels of the file system. A dictionary is a file
containing any number of items or entries. These entries supply definitions for
lower-level dictionaries and data level files. Dictionaries contain the following
types of items:
•
Account Definition items.
•
File Definition items (D-pointers).
•
Verb Definition items.
•
Attribute Definition items.
Account Definition items and File Definition items are both D-pointers; that is,
st
they both contain a D-code as the 1 line of the entry. In addition, there are Qpointers that reference D-pointers that exist as synonym definitions. Verb
Definition items are available in each account, providing access to system
programs. Attribute Definition items created in the file dictionary describe the
structure of the data file.
4-2
Only the SYSTEM Dictionary contains Account Definition items. Only the
Master Dictionary contains Verb Definition items. All three types of dictionaries
contain File Definition items. You can find Attribute Definition items in the file
dictionaries as well as the Master Dictionary.
SYSTEM Dictionary
The SYSTEM Dictionary organises information about user accounts. It contains
an Account Definition item for each user on the system. In addition, it contains
File Definition items for various system files.
The SYSTEM Dictionary is accessible from the SYSPROG account. A system
administrator uses this account to maintain the UniVision system. To create a new
account, the administrator invokes CREATE-ACCOUNT. It creates a Master
Dictionary for the account and copies all the items from NEWAC, a prototype
Master Dictionary, into it. In addition, it creates an Account Definition item in the
SYSTEM Dictionary.
You can create account synonyms to reference an Account Definition item. These
items are Q-pointers pointing to the Account Definition item. In this way, an
administrator can provide individual user IDs, as well as security privileges, to
users of the same account.
You should not update entries in the SYSTEM Dictionary while there are other
users logged onto the system. When users log on to the system, the UniVision
system establishes pointers to data in the SYSTEM Dictionary, and updating this
dictionary can destroy these pointers. However, you can create a new account at
any time. Creating new items does not affect existing pointers.
In addition, the SYSTEM Dictionary contains pointers to a number of important
system-level file. The Section entitled Account Management discusses systemlevel files.
Master Dictionary
Each account has one Master Dictionary containing the vocabulary for that
account. Primarily, the Master Dictionary contains Verb Definition items, File
Definition items, and keywords.
At the time of its creation, the Master Dictionary is a copy of the NEWAC file
defined in the SYSTEM Dictionary.
File Dictionary
Each data file must be associated with a file dictionary on the level above it. The
file dictionary points to the data file and describes the structure of the data file. It
is possible for more than one data file to share the same file dictionary.
4-3
Some file dictionaries do not have an associated data file. You refer to these files
as single-level files and they might contain actual data. A single-level file points
to itself. You can reference it as a file dictionary or as a data file.
Data Files
In UniVision a database file comprises two physical files: a dictionary describing
the structure of the database and a data file containing the actual data stored on
disk. In other words, the system keeps raw data in one place and stores the
definition of that data separately in the dictionary. You can store a piece of data in
a single location, unencumbered by its description. The dictionary contains this
description, and it might contain multiple descriptions of the same piece of data.
This arrangement provides a tremendous amount of flexibility in setting up a
database, permitting different logical views of the same set of data.
The system organises a data file as a collection of variable length items. It
organises an item as a sequence of variable length attributes. A unique item ID
identifies each item. For example, you assign items, in the ORDERS file, a
sequential numeric item ID that appears on a printed form as the order number.
It is possible for multiple data files with a similar structure to share a single
dictionary.
Dictionary Items
The section describes the different types of items found in dictionaries.
Account Definition Items
You create Account Definition items using CREATE-ACCOUNT, and they appear
only in the SYSTEM Dictionary. An Account Definition item is a D-pointer that
references the location of the Master Dictionary for the account it defines. The
Account Definition item supplies the account name and password, sets the
privilege level for the account, and defines a number of options for the account.
Item ID
The item ID of an account Definition item is the name of the
account. It serves as the user's logon ID or user ID.
Attributes
Account Definition items can have 13 attributes. The system
reserves attribute 4 and 11, and therefore they are empty.
1. Definition Code.
A D indicates a File Definition item.
2. Base
4-4
The base frame ID is a positive integer indicating
the starting location of the file. CREATE-FILE
assigns this value automatically.
3. Modulo
The modulo is a positive integer indicating the
number of groups occupied by the Master
Dictionary for the account. The user supplies it as
a parameter during file creation. To change the
modulo, edit attribute 13 to resize a file during a
file save and restore
4. Reserved
5. Retrieval Codes
An optional list of file-access locks associated
with the account. The user defines the format of
retrieval codes. If a user accesses a file containing
a retrieval lock the system compares the code in
Attribute 5 of the Account Definition item and
Attribute 5 of the Account Definition item. If you
have specified multiple values, it matches any
single value. For more information, refer to the
section entitled File Security in the Section
entitled File Management
6. Update Codes
An optional list of file-update locks associated
with the account. The user defines the format of
the update code. If the user attempts to modify a
file containing an update lock, the system
compares the code in Attribute 6 of the file
Definition item and Account Definition item. If
you specified multiple values, it matches any
single value. UniVision BASIC OPEN fails if the
lock codes do not match, as it assumes that if you
can open a file, you might try to write to it. For
more information, refer to the section entitled File
Security in the Section entitled File
Management.
7. Password
The system stores a user password in encrypted
format. When you create the account you establish
the user password. If you do not define a
password, Attribute 7 is null. To change a
password, use PASSWORD.
4-5
8. Privilege Level
A code indicating the system privilege for the
account. If this attribute is null, the lowest
privilege level, SYS0, applies. Each level includes
the privileges on lower levels.
SYS0
Level 0 is the lowest level of privilege.
Users of accounts with SYS0 privileges
can only run the application software.
SYS1
Level 1 permits updating of the Master
Dictionary of the account and the use of
tape.
SYS2
Level 2 permits use of the BASIC
Debugger, DUMP, file-save and filerestore processors.
SYS3
Level 3 id the highest privilege level. It
provides unrestricted access to all files
regardless of retrieval and update
codes.
9. Account Options
One or more codes that enable various options for
the account.
4-6
B
Disables <BREAK> for this account.
O
Automatically logs off user when a
security
violation
occurs.
The
SECURITY-LOG file records security
violations.
R
Enables the RESTART option, this
causes the system to execute the Logon
Proc when user exits the debugger
using END.
T
Prevents the user from accessing UCL
directly providing a Proc named
account-name @ UCL exists in the
user's master Dictionary or a Proc
named @UCL exists in ERRMSG file.
U
Specifies that you want to update the
accounting History file, a file that
maintains a log of user logon times and
the number of pages sent to the printer,
whenever the user logs off.
10. Width
A positive integer indicating the maximum
column width of the item ID column. Used by
VISION processor.
11. Reserved
12. User Process Code
A list of user process numbers permitted to log
onto the account. A value mark separates
individual process numbers with value marks. If
null, all processes can log onto the account. You
can use Process 0, associated with the system
console, to log onto any account regardless of the
list of user processes permitted.
13. Reallocation
A positive integer specifying a new modulo for
the Master Dictionary. You can enclose this value
in parentheses. The reallocation of the Master
Dictionary occurs during a file-restore.
The system administrator should make updates to the Account Definition item
only when there are no other users logged on to the system.
The following example shows an Account Definition item:
STAFF
001 D
002 6572
003 7
004
005 CD]CE
006 D]F]G
007 FqKs3IXsfm
008 SYS1
009 U
010 10
This item for the account named 'STAFF' specifies an encrypted password, file
retrieval and update codes, SYS1 privileges, and the account option: the
Accounting History file records the time of logon (U).
4-7
Account Synonym Items
Account synonyms are Q-pointers to Account Definition items that allow you to
set up individual user IDs for the same account. It is possible to create them using
the Editor.
Item- ID.
An Account Synonym items that is a pointer to an Account
Definition item. The item ID is another name for an account
that already exists.
Attributes
Account Synonyms usually have 10 attributes. Only
Attributes 1 and 2 differ from those in Account Definition
items.
1. Definition Code
A Q indicates a Synonym Definition item or Qpointer.
2. Account
The name of the Account Definition item, that is a
D-pointer in the SYSTEM Dictionary.
The remaining attributes are the same as described for the Account Definition
item, except that the system ignores the reallocation parameter (line 13). If the
Account Synonym does not specify these attributes, the retrieval and update codes
are the values specified in the Account Definition item. The system assumes the
password is null and the privilege level is SYS0.
The following example shows an Account Synonym item:
JOHN
001 Q
002 STAFF
003
004
005 CD
006 D
007 U9Pau6RDo
008 SYS1
009 OU
010 10
This sets up the user ID, JOHN as a Q-pointer to the STAFF account. It
establishes a password and SYS1 privileges, and specifies its own file retrieval
and update codes.
4-8
Verb Definition Items
Verb definition items appear only in the Master Dictionary of the account. The
system copies them into the Master Dictionary from the NEWAC file when
creating the account. It is possible to modify each Master Dictionary such that all
accounts cannot have the same set of Verb Definition items.
A Verb Definition item allows a user to invoke a system processor. These items
are the verbs or commands it is possible to execute at the UCL prompt. The
Section entitled The UniVision Control Language describes the format of Verb
Definition items.
File Definition Items
File Definition items are D-pointers that point to the location of a file. The file can
be a single-level file, in which case it has no data-level file associated with it. This
SYSTEM Dictionary and the Master Dictionary are two examples of single-level
files. Most files, however, have two levels. In this case, the File Definition item
points to a dictionary file which, in turn, contains a D-pointer to a data file. Dpointers occur in the SYSTEM Dictionary, the Master Dictionary, and file
dictionaries. Use CREATE-FILE to create File Definition items.
Item ID
A File Definition item is a pointer to a dictionary or data file.
The item ID is the actual name of the referenced dictionary
or data file. If it points to a data file, the item ID is the same
as the name of the file.
Attributes
File Definition items can have 13 attributes. The system
reserves attributes 4, 11, and 12, and therefore they are
empty.
1. Definition Code
A D indicates a File Definition item. In addition, it
is possible to use the following Definition Codes.
DX
Do not save the file during file-save;
the file does not exist following a filerestore.
DY
Only save the file sizing parameters,
not its data, during a file-save; the file
is empty following a file-restore.
4-9
DC
2. Base
Indicates that it is possible to use the
file for UniVision BASIC programs.
The dictionary usually contains items
that are pointers to frames containing
object code. You can specify 'DCX' and
'DCY'.
The base frame ID is a positive integer indicating
the starting location of the file. CREATE-FILE
assigns this value automatically. Do not change
this value.
3. Modulo
The modulo is a positive integer indicating the
number of groups occupied by the file. The user
supplies it as a parameter during file creation. To
change the modulo, edit Attribute 13 to resize a
file during a file-save and restore. Do not change
this modulo in Attribute 3.
4. Reserved
5. Retrieval Code
An optional user-supplied security code used to
restrict access to a file. When specified, its value
must match any retrieval code in the account
Definition item for the system to access the file.
6. Update Code
An optional user-supplied security code used to
prevent modification of a file. When specified its
value mark must match any update code in the
Account Definition item for the system to modify
the file.
7. Conversion Code
A conversion specification applied to the item ID.
Used by the VISION processor.
8. Correlative Code
A correlative specification applied to the item ID.
Used by the VISION processor.
9. Justification
A code specifying the justification of the item ID
in a column. L indicates left-justification and R
indicates right-justification. Used by the VISION
processor.
4-10
10. Width
column width of the item ID column. Used by
VISION processor.
11. Reserved
12. Reserved
13. Reallocation
A positive integer specifying a new file modulo.
You can enclose this parameter in parentheses.
Use this modulo to resize the file during a filerestore.
The following example of a File Definition item shows the entry in the Master
Dictionary for the ORDERS file.
ORDERS
001 D
002 6850
003 7
004
005
006
007
008
009 L
010 10
011
012
013 (3)
! Note:
The modulo of the file is currently 7. However this
example specifies a reallocation parameter of 3 so that
when the system saves and restores the file from tape, it
reduces the number of groups.
File Synonym Items
A File Synonym item is a Q-pointer to a File Definition item. It is possible to
create Q-pointers using the Editor. In addition, use SET-FILE to establish a
temporary Q-pointer named 'QFILE'.
! Note:
You cannot copy D-pointers using COPY; therefore, Qpointers are the only acceptable entries for the file
synonyms.
4-11
Item ID.
The item ID is the name you choose for a file already
existing in the same account or in another account.
Attributes.
File Synonyms usually have 3 to 10 attributes. Only
attributes 1, 2, and 3 differ from those in File Definition
items.
1. Definition Code
A Q indicates a Synonym Definition item or Qpointer.
2. Account.
The name of the account containing the actual
definition of the file. If not specified, the file
definition is in the same account.
3. Filename
The name of the reference file. It is the item ID of
the actual File Definition item. If not specified, it
refers to the target account's Master Dictionary. In
addition, a File Synonym item can point to the
Master Dictionary of another account.
The remaining attributes are the same as described for the File Definition item.
However, you cannot specify a reallocation parameter for a Q-pointer. The
following example of a File Synonym item, BOOK-CAT, shows an entry for
accessing the BOOK-CATALOG in the STAFF account.
BOOK-CAT
001 Q
002
003 BOOK-CATALOG
004
005
006
007
008
009 L
010 10
Line 2 is empty because the example is defining the file synonym in the same
account as the one that contains BOOK-CATALOG. To access the file from
another account, line 2 would contain 'STAFF', the name of the account.
Attribute Definition Items
Attribute Definition items define the format of items in the data file. It is possible
to create these items using the Editor. The Section entitled Creating a Database,
described the creation of Attribute Definition items in the process of building a
dictionary.
4-12
Item ID.
A logical name used to reference the contents of the attribute
in VISION statements.
Attributes.
Attribute Definition item can have 10 attributes. The system
reserves Attributes 5 and 6, and therefore they are empty.
1. Definition Code.
Any one of these Definition Codes specify an
Attribute Definition item.
A
An
Attribute
Definition
item
referencing the contents of an attribute
in the data file.
S
An Attribute Synonym. Same as 'A' for
all practical purposes. LISTDICT sorts S
after A codes. Usually the system
creates attribute synonyms as a
numerical sequence of item IDs to
define the default output specifications
for VISION reports.
I
A VISION phrase follows in line 2.
X
A place-holder item skipped when
maintaining sequence of numeric item
IDs to specify the default output
specification for VISION reports. The
system does not display the attribute
reference by an X item/
2. Attribute Number.
An integer identifying the attribute by its
sequential location, also called the Attribute mark
Count (AMC). An attribute number of 0
references the item ID. A 0 or any number greater
than the number of attributes that exist in the file
references data derived or computed rather than
actually stored on disk. In addition, if line 1
defines a phrase, the actual phrase interpreted by
VISION starts on line 2.
4-13
3. Tag
An optional name used in place of the item ID as a
column heading in VISION reports. The backslash
(\) is a symbol, reserved by the system, causing no
tag to be output. You can use value marks
(CTRL-]) to indicate a line break, making it
possible to place a column heading on multiple
lines. If the heading is shorter than the column
width, the system pads it with dots(…).
4. Structure.
An optional code defining an associative structure
for two or more multi-valued attributes. A
structure code of 'C' indicates a Controlling
attribute; a structure code of 'D' indicates a
Dependent attribute. You can only list Dependent
attributes in a VISION report when the
Controlling attribute appear in the output
specification.
5. Reserved.
6. Reserved.
7. Conversion Code.
A conversion specification applied to the contents
of the attribute. Used by VISION processor.
8. Correlative Code.
A correlative specification applied to the contents
of the attribute. Used by the VISION processor.
9. Justification.
A code specifying the justification of the output
field in a column. In addition it affects the sorting
of data.
4-14
L
Left-justified, generally the case for
alphabetic data. If data exceeds the
length defined by the maximum column
width, it wraps to the next line,
beginning at the first character over the
maximum length.
R
Right-justified, generally the case for
numeric data.
T
Left-justified. Type of justification used
for textual data that might include
embedded blank spaces. If data exceeds
the length defined as the maximum
column width, it wraps to the next line,
starting at a blank space. Used by the
VISION processor.
10. Width
column width of the column. Used by VISION
processor.
The following example shows an Attribute Definition item taken from the
CUSTOMERS file:
PHONE
001 A
002 6
003 Phone
004
005
006
007 ML(###-###-#### ####)
008
009 R
010 17
th
This item defines the 6 attribute in a data item. It supplies a column heading and
a conversion code that presents this numeric data in a conventional format. If you
store the following piece of data in Attribute 6 of an item in the data file.
5168769091
and apply a conversion code (line 7) on output, the data has the format of a phone
number:
516-876-9091
The CUSTOMERS Dictionary
Table 4-1 shows the contents of some of the Attribute Definition items in the
ORDERS dictionary.
4-15
Item ID
CUST.ID
DATE
PRODUCT
QTY
PAYMENT
D/CODE
A/AMC
S/NAME
S/AMC
V/CONV
V/CORR
V/TYPE
V/MAX
A
1
Customer ID
A
2
Date of Order
A
3
Product
C:4
A
4
Quantity
D;3
A
5
Payment
L
5
R
3
L
10
D2/
L
10
L
10
Table 4-1. ORDERS Attribute Definition Items
This table describes a data file item format of five attributes. The attribute number
(A/AMC) references the sequential location of attributes in the data file item. The
codes stored in S/AMC and V/CONV require some further explanation, covered
in later sections.
The Structure of Items
In conventional database terminology, records and files are equivalent to items
and attributes. However, the terms, records and fields do not convey the structure
of item in the UniVision system fully.
Each item is a variable-length string of characters. The presence of delimiters,
special characters that indicate structural elements define the structure of this item.
Table 4-2 shows the UniVision system delimiters. An item is a sequence of
variable-length attributes. An attribute corresponds to a line when you list the item
vertically (such as in Editor). Attributes can contain any number of values. If an
attribute contains more than one value the system considers it to be multi-valued.
values, and in turn, you can divide it further into any number of sub-values.
Representation
ASCII Value
Attribute
^
254
Value
]
253
Sub-Value
\
252
Mark
Table 4-2. UniVision System Delimiters
Using these structures, you could structure a database file such that each item was
the equivalent of a collection of records and each attribute was the equivalent of a
collection of fields. The value mark delimits the contents of each field within the
attribute and the sub-value mark delimits multiple entries in a single field.
4-16
Multi-valued Attributes
To understand the usage of multi-valued attributes, look at the structure of an
ORDERS database created to capture the data on the sample form in Figure 4-2
Purchase Order
03128
No.
To.
John Swenson
14 Crosswoods Place
Fremont, NV
Product
X47-180
X47-191
X25-340
Quantity
2
2
1
Date:
16/4/89
Ship Via: U.P.S.
Payment: Cash
Amount
25.00
32.00
21.00
78.00
Original
Figure 4-2.
A sample order form
You can use multi-valued attributes to describe 'line items' on an order form. The
shaded area in Figure 4-2 holds the line items on the printed form. A line item
represents information about the purchase of a particular product. The customer
might place orders for several different products in different quantities with each
having a different price. The rest of the data fields on this form contain only a
single piece of data, such as the customer's name and address, a credit card
number or the amount of the order.
Each order has an order number, outlined in the top right hand corner of the form.
This number serves as the item ID to identify each order in the database file. Each
item in the data file has the following sequence of attributes:
4-17
CUSTOMER-ID
DATE
PRODUCT
QTY
PAYMENT
SHIP
1
2
3
4
5
6
There are six attributes. Notice that not all data fields on the form are in use. For
instance, there is no AMOUNT or TOTAL-AMOUNT attribute. That is because it
is possible to derive this information from data that already exists in the file. The
actual data file item storing the data from the order form would look like this:
JSEWN14CRO^7414^X47-180]X46191]Y25340^2]2]1^CASHÛPS
A caret (^) represents an attribute mark. PRODUCT and QTY are multi-valued
attributes; that is, each attribute has several pieces of data separated by value
marks. A right bracket (]) represents a value mark. In the above example, each
multi-valued attribute has three values.
You associate any group of multi-valued attributes as a unit so that VISION
st
reports display related values together. In other words, the 1 value in PRODUCT
corresponds to the first value in QTY. Figure 4-3 illustrates this concept.
Remember that a multi-valued attribute is a structure defined by specific
delimiters in the data file item. The attribute definition in the dictionary does not
describe it. Therefore, it is possible to create an attribute for which some items
might have multiple values while others do not. For example, if a person supplied
two home phone numbers, you could place both numbers in the data file item,
separated by value marks.
4-18
10139
CUSTOMER-ID
JSWEN5390
DATE
PRODUCT
16/4/89
QUANTITY
X47-180
X47-191
X25-340
2
2
1
PAGE1
PAYMENT
SHIP
CASH
U.P.S
12:47:19 24 MAY 1989
ORDERS
CUSTOMER ID
DATE
PRODUCT
QTY
PAYMENT
SHIP
10139
JSWEN5390
16/4/89
X47-180
X47-191
X25-340
2
2
CASH
UPS
END OF LIST
>
Figure 4-3.
Multi-valued attributes create another level of structure within an item. It is
possible to associate these attributes so that reports display corresponding values
together in reports.
The ORDERS Dictionary
The ORDERS file implements multi-valued attributes to describe the data in a
single order transaction. When a customer places an order, the system stores the
data in an item in the ORDERS file. A unique product code identifies each book.
For example, when displayed by LIST-ITEM, item 10118 in the ORDERS file, has
the following structure:
> LIST-ITEM ORDERS '10118'
001
002
003
004
005
006
10118
DROBI5424
7563
N01]QR02]N04
3]2]1
CASH
UPS
4-19
Attribute 3 contains the code numbers of the ordered books and Attribute 4
contains the number of books ordered. Attributes 1, 2, 5, and 6 each have only a
single value. The system derives the rest of the data describing an order
transaction, such as PRICE, TITLE, AMOUNT, and TAX, from existing data.
Value marks, entered in the file with <CTRL-]> separate the pieces of data in each
multi-valued attribute.
The interpretation of data in item 10118 is as follows:
•
3 copies of book N01
•
2 copies of book QR02
•
1 copy of book N04
Controlling and Dependent Specifications
You can define the relationship that multi-valued attributes have to one another
further using a Controlling attribute and one or more related Dependent attributes.
Controlling and Dependent attributes identify a unit of related data. You cannot
display a Dependent attribute in a report unless you include the related Controlling
attribute as well. This is because the data in Dependent attributes might otherwise
have no meaning. For example, it would make little sense to display the number of
books ordered unless you identify the books themselves in the report.
Line 4 of an Attribute Definition item determines whether an attribute is
Controlling, Dependent, or neither. For example, the Attribute Definition item for
PRODUCT in the ORDERS dictionary defines this attribute as Controlling and
links it to Dependent Attribute 4 (QTY):
>LIST-ITEM DICT ORDERS 'PRODUCT'
001
002
003
004
005
006
007
008
009
010
PRODUCT
A
3
PRODUCT
C:4
L
5
The Attribute Definition item for QTY defined this attribute as dependent and
links it to Controlling Attribute 3 (PRODUCT):
4-20
QTY
001
002
003
004
005
006
007
008
009
010
A
4
QUANTITY
D;3
R
3
Correlatives and Conversions
A database provides for the storage and retrieval of data. The reason for creating a
database, however, is so that you can process the data easily for reports. If you
store data from a series of customer orders on the computer, you would expect to
do more than simply retrieve that data. You might accumulate totals so that you
could report the number of units sold or the dollar amount in sales per day, per
week, per month and so on. A database provides a way to transform data into
information.
Correlatives and conversions provide a great deal of flexibility in creating
VISION reports. You can define conversions to convert raw data into a particular
format. You can define correlatives that permit you to access and process data in
existing attributes or other database files. Normally you store conversions in
Attribute 7 and correlative in Attribute 8 of an Attribute Definition item. Refer to
the Section entitled Correlatives and Conversions in the VISION Reference
Guide for the full description of the usage of correlative and conversion codes.
Stored Format and Output Format
Correlatives and conversions add flexibility to the way you store and handle data.
Conversions translate data from a raw or stored format to output format, for
example, you could translate a phone number consisting of a string of fourteen
numeric characters as follows:
Stored Format
Output Format
61724577853397
617-245-7785 3397
It is more efficient to store the data without the hyphens or blank spaces. In
addition, it makes it easier to achieve a consistent output format. For instance, to
put the area code in parentheses, you need change only the conversion code in the
dictionary, not the data itself. Correlative codes often manipulate the data in one
attribute by extracting, concatenating, or substituting data from other attributes.
For example, you can construct a customer's full name by concatenating the last
name and the first name from the CUSTOMERS file as follows:
4-21
Code
First Name
Last Name
Full Name
C;2 1
JULIE
BUCKLER
BUCKLER JULIE
The correlative code 'C;2 1' specifies that you form a customer's full name by
concatenating Attribute 2 and Attribute 1 and use a blank space as a separator.
Similarly, if you store a person's name as a full name, you could use a correlative
to extract the person's first or last name.
Formatting Dollar Amounts
Using conversions to format dollar amounts is a typical example. The Attribute
Definition item for AMOUNT (amount of sale) in the ORDERS dictionary
contains a conversion to produce a formatted dollar amount:
>LIST-ITEM DICT ORDERS 'AMOUNT
001
002
003
004
005
006
007
008
009
010
AMOUNT
A
0
AMOUNT
MR2$
A;N(QTY)*N(PRICE)
R
10
The conversion MR2$ specifies the format of the dollar amount. The M specifies
that you want to convert numeric data. The following specifies the format of the
amount:
•
Right-justification of the amount (R).
•
Two digits follow the decimal point (2).
•
A dollar sign precedes the amount ($).
Assume that you stored the amount of sale for an item in the ORDERS file as
'1100'. The conversion operates on this data element an produces the result:
$11.00.
If a VISION report included the AMOUNT attribute, the conversion code would
ensure that all of the dollar amounts were right-justified and, therefore, properly
lined-up
4-22
! Note:
The system actually derives the amount of sale by a
correlative that multiples the attribute QTY by the
attribute PRICE. You can find a description of this
correlative in the section entitled Manipulating Existing
Data.
Formatting Dates and Times
You can use conversion codes to specify formatting for dates and times. Normally
the system stores dates and times in internal format, an integer value that is much
easier for processing and storage. In order to output this type of numeric data, you
must convert it into a specified format. The following shows two examples from
the ORDERS file:
Item ID
DATE
TIME
D/CODE
A/AMC
S/NAME
S/AMC
V/CONV
V/CORR
V/TYP
V/MAX
A
2
Date of Order
A
7
Time of Order
D2/
MTHS
L
10
L
10
Table 4-3. Date and Time Conversion
You format dates using two digits for the year and a slash character (/) as a
delimiter. For example:
04/04/88
You format times using the 12-hour format with AM or PM appended, and include
seconds. For example:
09:13:56 AM
For alternative formats, refer to the Section entitled Correlatives and Conversion
in the VISION Reference Guide.
Manipulating Existing Data
The BOOK-CATALOG file describes the inventory for the mail-order publishing
business. Table 4-4 shows the contents of three of the Attribute Definition items in
the BOOK-CATALOG dictionary.
4-23
Item ID
AUTHOR
TITLE
PRICE
AMOUNT
D/CODE
A/AMC
S/NAME
V/CONV
V/CORR
V/TYPE
V/MAX
A
1
Author
A
2
Title
A
3
Price
MR2$
L
20
T
20
R
8
A
0
Amount
MR2$
A;N(QTY)*N(PRICE)
R
10
Table 4-4. BOOK-CATALOG Attribute Definition Items
The preceding Attribute Definition items describe the structure of a BOOKCATALOG data file item. For example, the data item for the book whose code is
N01 contains the following information:
>LIST-ITEM BOOK-CATALOG 'N01'
N01
001 STRANG
002 OPERATING SYSTEM CONCEPTS
003 2000
The data stored in the BOOK-CATALOG file is relatively stable (the prices of the
books might change, but the book titles and authors remain the same). It makes
sense, therefore, to maintain inventory information in this file and to reference
(not duplicate) it in the ORDERS file.
The dictionary entry for 'AMOUNT' contains a correlative used to derive its value
by manipulating other values in the database. The correlative
A;N(QTY)*N(PRICE) multiples the data in two other numeric attributes in the
ORDERS file to derive the data for AMOUNT. Specifically, this correlative
multiplies QTY by PRICE.
Use the A code to specify the processing. The N function identifies the attribute by
name. In addition, it is possible to reference attributes by AMC. For example,
A;2*3 multiples the value of Attribute 2 by the value of Attribute 3. The
expression A;2*"3" multiples the value of Attribute 2 by the number 3. In other
words, you determine the amount of sale automatically by multiplying the number
of books ordered by the price of a single book.
4-24
Translating Data from Another File
The Tfile (file translation) code eliminates the need for duplicating data in related
files by retrieving data from one file for use in another file. To access the remote
file, you must create the dictionary entry containing the Tfile correlative with the
AMC specifying the attribute of the source item that provides the item IDs for
items in the target file.
Assume that a user wants to be able to generate reports from the ORDERS file
that include book titles and prices. The BOOK-CATALOG file contains this
information in Attributes 2 and 3 respectively. The item IDs in BOOKCATALOG are unique character strings (PRODUCT) that identify each book.
In addition, the ORDERS file uses the PRODUCT attribute, but as Attribute 1.
Since you can use PRODUCT to link data in the ORDERS and BOOKCATALOG files, this is the only piece of data required in the ORDERS file to
identify a book uniquely.
Table 4-5 shows the Attribute Definition items for TITLE and PRICE in the
ORDERS file:
Item ID
TITLE
PRICE
D/CODE
A/AMC
S.NAME
V/CONV
V/CORR
V/TYP
V/MAX
S
1
S
1
TBOOK-CATALOG;X;;2
T
40
TBOOK-CATALOG;X;;3
R
8
Table 4-5. ORDERS File Attribute Definition Items
The Tfile correlative for TITLE specifies that you want to retrieve the data from
Attribute 2 of the BOOK-CATALOG file. The Tfile correlative for PRICE
specifies Attribute 3 of the BOOK-CATALOG file. the X sub-code shown for
both TITLE and PRICE causes the system to return a null value if for any reason
it cannot return the data.
With the preceding Tfile correlatives in place, there is no need to duplicate lengthy
titles in each order item. In addition, you could change the price of any book in the
BOOK-CATALOG file, and generate reports from the ORDERS files would
reflect the new data automatically.
4-25
Section 5
UNIVISION DATABASE MANAGEMENT
SYSTEM
The UniVision environment is a powerful, multi-user database management
system (DBMS) designed to run the extensive library of applications available for
the Pick data model. UniVision is an efficient and high-performance DBMS,
implemented using state-of-the-art object-oriented programming techniques.
UniVision is designed for the open systems environment, and is written in the
C++ programming language.
This section describes the fundamental structure of UniVision and covers the
following main areas:
•
File access methods
•
Peripheral device management.
Physical Mapping of the Disk
UniVision organises the hard disk into the following areas:
•
File Area
•
Available Space Area.
The following is an example of the report generated on UniVision by WHAT.
13:19:20
CORE
LINES
65152 254
24 AUG 1993
MAXUSERS [254}
CURRENT # USERS [21]
PROCESSES PCB0 WSSTART WSSIZE SYSBASE/MODULO MAXFID OVRFLW
2500
0400
N/A
N/A
1
3
756135 119612
Overflow Area
The overflow area is just available disk space. It consists of a pool of frames that
the system can allocate dynamically to create files, or that various system
processors can use as additional data space by various system processors. For
instance, when a group needs an additional frame for storage of items, the system
takes this frame from the overflow area.
UniVision Database Management System
5-1
The heading OVRFLW in the WHAT report lists the number of frames in the
overflow area. In the sample report, there are 119612 available frames. At the end
of the overflow area is the maximum frame ID, that appears under the MAXFID
heading in the WHAT report.
How You Use the Overflow Table
On a new system, and following a file-restore, the overflow area consists of a
single block of contiguous frames. Contiguous space consists of adjacent frames
allocated as one or more blocks. As the system returns frames to the overflow
area, this area becomes more fragmented, consisting of multiple blocks of
contiguous frames. The system keeps track of these sets of blocks in the Overflow
Table. This table contains a pointer to the beginning and end of each block.
The UniVision system uses the Overflow Table to handle requests for additional
frames. If it requests a block, the system assigns frames from the first contiguous
block of space that is equal to or greater than the amount requested.
Frame Formats
Data frames have a specified format that places linking information at the start of
the frame. The frame size is 2048 bytes, data comprises 2000 bytes with the
remaining 48 bytes reserved for linking information. Sometimes you refer to data
frames as linked frames, because they contain the link information. UniVision can
combine blocks of frames to create a file.
You can display the contents of disk frames using DUMP. DUMP displays the
contents of disk frames, including information about forward and backward links,
and has the following syntax:
DUMP frame-ID1[frame-ID2] [options]
frame-ID1
number of the frame you want to display.
frame-ID1-frame-ID2
specifies a range of frames
options
5-2
can be any of the following:
B
Display frame branching details.
G
Group option. Displays all forward-linked frames,
attached to the specified frame. Used with U, G
displays all backward-linked frames in the group.
L
Link option. Only displays
information; does not display date.
N
Suppresses automatically paging.
frame
link
P
Sends output to the printer.
U
Traces data or links logically forward using
backward links instead of the default forward
links.
X
Displays data in hexadecimal format rather than
ASCII.
The following is an example of the output from DUMP.
forward link
backward link
FID
FID :
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
hexadecimal equivalent
9530 :
9531
9246
(253A :
253B
241E)
:....____;%...$..............................0...T
:
:3 THEN^
database<<15>>=''^
END^
GOSUB reb :
:uild.contacts^
CRT @(30,33):database<<14>>:@(-4):^ :
:
IF database<<33>> NE ' ' THEN^
GOSUB contrac :
:t.update^
END^
GOSUB validate.normal^
GOS
:
:UB rebuild.contacts^
IF old.database NE databas
:
:e THEN
IF debug=true THEN^
MAT fld.n
:
:ew=''^
MAT fld.old=''^
CRT @(0,4):
:
:@(-3):^
do.debug=false^
FOR x = 1
:
:TO 10^
fld.new(x)=database<<field<<1,x>>>>^ :
:
fld.old(x)=old.database<<field<<1,x>>>>^
:
:
IF fld.new(x) NE fld.old(x) THEN^
:
:
CRT 'Field ':fields<<1,x>>"L#2":' differs'^
:
:
CRT ' Old ':fld.old(x)^
CRT
:
:' New ':fld.new(x)^
do.debug=true^
:
:
END^
NEXT x^
CRT 'Att diff :
:er:':^
FOR x = 1 TO DCOUNT (old.database,am
:
:)^
IF old.database<x> NE database<x> THE
:
:N^
CRT ' '':x:^
END^
:
:NEXT x^
CRT^
CRT 'Old record ':DCO
:
:UNT(old,database,am);' / New record ':DCOUN(datab
:
For more detail regarding DUMP refer to the UniVision Command Reference
Manual.
5-3
Physical Item Structure
An item is a variable-length string containing delimiters or special characters
indicating its structure. Each item begins with a null character and a four-character
binary count field specifying the number of characters that make up the item. An
item-ID follows the count field. An item contains any number of attributes,
delimited by attribute marks (ASCII 254) printed as a caret (^). Attributes can
contain any number of values, delimited by value marks (ASCII 253) printed as a
right bracket (]). A value can contain any number of sub-values, delimited by subvalue marks (ASCII 252) printed as a backslash (\). At the end of the item there is
a segment mark (ASCII 255) printed as an underscore (_). Two consecutive
segment marks indicate the end of the item and the end of the group.
The output from DUMP, shown above shows only the first page of a two page
report. The system displays the data in lines of 50 bytes each. You can see that the
data begins with the item count (in hexadecimal) of the first item followed by its
item ID. It is possible to find attribute mark (^), value marks (]) and the segment
mark (_) that indicates the end of an item.
The DUMP report actually shows over 900 bytes of data in the above frame;
however almost half the frame contains characters left over from previous use.
This is referred to as 'Lint'. Returning a frame to the overflow area and allocating
it again does not erase data in the frame; new data overwrites the old data. The
end-of-group mark indicates the end of useful data to the system. To indicate that
the frame does not contain any useful data (that is, that it is empty), commands
like CREATE-FILE place a segment mark as the first byte of data following the
linking information.
File Access
The file structure allows a user to run UniVision application code that has less
than the optimal file allocation without impacting performance severely. Close
attention to file sizing and weekly or monthly file restoring is not essential with
UniVision. UniVision reduces the need for periodic file resizing dramatically, thus
minimising downtime.
When you create a file on UniVision, it establishes the primary file space. It sets
aside one two thousand (2 Kbyte) page for each group specified by the modulo in
the create file process. UniVision establishes the primary pages for a file and, in
the case of badly fragmented free disk space, these do not have to be contiguous.
Each group can contain an unlimited number of pages of disk space. Each page
can contain up to two thousand bytes of data. As a page of disk space fills with
data items, the system adds additional pages. Conversely, as the system removes
or deletes items, it returns pages to the available space table for re-use.
5-4
Each group contains a number of items. A unique item identifier or key
determines the items in the group. The system applies each key to the UniVision
hashing algorithm in an attempt to distribute items evenly across all groups.
As you add items to a file, each group can contain a large number of items. To
prevent long sequential searching for data within a group. UniVision continues to
add data to a group until the group contains one hundred and fifty items. Once a
group expands beyond one hundred and fifty items, the system assigns a subgroup to a group.
A sub-group contains five groups. Each sub-group can grow to one hundred and
fifty items, then the sub-group can again split into a sub-sub-group. The splitting
can continue for a long as required.
In the following example, group two contains five pages and over one hundred
and fifty items. The group attaches an additional five sub groups, in which subgroup three expanded to over one hundred and fifty items. The system attaches a
sub-group to sub-group three of the original group two. The process of creating
sub-groups continues as many times as required to save all the items in the group.
This file structure allows for a poorly allocated file. However, UniVision
compensates for this by dividing the groups for improved item retrieval
performance.
5-5
Customer File
Group 1
Group 2
Sub-Group
Sub-Group
Group 3
Figure 5-1.
File Structure of UniVision
Retrieving Items
It is possible to appreciate the efficiency of the UniVision file access method
when compared with a purely sequential search of a file. A sequential access
method locates an item within the file by reading all characters from the beginning
of the file until it locates the item ID or reaches the end of the file. As a
consequence, you retrieve items located at the beginning of the file much faster
than those at the end. In addition, performance suffers as files get larger.
A sequential access method is analogous to searching an alphabetical list
beginning with the A's and proceeding to search the B's and so on. If you wanted
to make a search on a list of names, it would locate names beginning with letters
towards the start of the alphabet faster than other names. A random-access method
of storing and retrieving items limits the search to a portion of the file.
5-6
Each item falls into a particular group based on its item ID. Once the system
locates that group, in conducts a sequential search of items in that group,
comparing item IDs. Each item's count field contains the size of the item, used to
locate the next item in the group. Instead of reading each character to look for the
segment mark indicating the end of an item, the system is able to jump ahead by a
specified number of bytes to locate the beginning of the next item. If the system
encounters a segment mark instead of a count field, this indicates the end of the
group. An empty group has a segment mark in the first data position.
UniVision's file access method, using the item ID to locate the group and find the
item within the group, is an efficient way to locate data. The system overhead
required to access an item is essentially independent of the actual size of the file.
Processes and Lines
A line refers to a serial communications port and the control structure that
manages the data as you send and receive it across the line. A cable running from
a serial device, such as a terminal, connects that device to one of the system's
communication ports.
The system number lines sequentially, starting with line 0, usually the system
console. Terminals, printers and modems connect to additional lines, usually
beginning with line 1. The system configuration is the basis for the number of
lines that are available on UniVision.
A user process, is a workspace that records the current state of processing tasks
for a particular user. It keeps track of the location of the user's Master Dictionary,
the location of a file being accessed, whether a printer or tape drive is in use, and
what system processor is executing. Each process is essentially independent of the
other processes on the system.
Almost all the software processors within UniVision have the capability to accept
input from a single line and send all output back to the same line.
On most Pick systems, lines and processes are not interchangeable because they
always remain linked. However, on UniVision it is possible to unlink a line from a
process, providing additional communications capabilities.
You called a line not linked to a process an available line, and sometimes call the
unlinked process a phantom process. You can link and unlink lines dynamically,
and can attach a process to an unlinked line. The commands listed in the following
table are available to link or unlink lines, and attach or detach lines. Refer to the
Section entitled Data Communications to see how to use them to connect a
modem to the system.
5-7
Command
Description
LINK-LINE
Creates a link between an available line and a
process. Only available from accounts with SYS3
privilege.
UNLINK-LINE
Breaks the link between a line and a process,
creating an available line and a phantom process.
Only available from accounts with SYS3
privilege.
LINE-ATT
Attaches a line to a process, providing exclusive
use of that line.
LINE-DET
Detaches an attached line from a process.
LINE-PROTOCOL
Displays line characteristics for specified lines.
LINE STATUS
Displays the status of a specified line of range of
lines.
LISTDEV
Lists the UniVision Line to UNIX Device
Relationship.
LISTPRO
Lists the UniVision Process to UNIX Device
Relationship.
CONVERSE
'Connects' an attached line and a linked line.
PROCESS-STATUS
Displays the status of a specified process or a
range of processes.
ACQUIRE-LINE
Acquires a UNIX line for subsequent use by
UniVision.
RELEASE-LINE
Releases an acquired line back to UNIX.
LIST-ACQUIRED-LINE
Lists UNIX lines acquired for UniVision use.
Table 5-1. Line Commands
A line can only link to one process. A process can only link to one line at a time,
but it can attach to however many lines are available. Attaching a line to a process
gives the process exclusive control over the line. The process can take input from
or send input to the attached line by using commands that specify the attached line
by number. Typically you do this using GET and SEND in BASIC.
By default, all input and output for a process uses the linked line. You cannot
direct input from a line to any other process. However, other processes can send
output to a linked line. If you require to prevent output being sent to the line,
attach a line, thereby gaining exclusive control of the input and output for a
process. The line is said to be 'linked and attached'.
5-8
A line can have one of the following statuses:
AVAILABLE
An available line is neither linked nor attached to any
process. You can send output to an available line from
another process.
LINKED
A process uses its linked line for all default input and output.
It is only possible to link a line to one process at a time. No
other process can receive input from a linked line. However,
it is possible for another process to send output to a linked
line.
ATTACHED
A process uses its attached line for any specified input and
output. You must specify the attached line by line number. It
is only possible to attach a line to one process at a time. The
process has exclusive control over the line. No other process
can receive input from or send output to an attached line.
LINKED and ATTACHED
The system uses a line linked and attached to a process for
all default input and output. The process has exclusive
control over the line. No other process can receive input
from or send output to the line.
ACQUIRED
The system has acquired the line from UNIX for subsequent
use by UniVision.
5-9
Line 0
Process 0
Line0 is linked to Process 0
Process 1
Line 1
Process 2
Line 2
Process 3
Process 3 is a phantom
Process not linked
to a line
Line 3
Line 3 is attached to Process 4
Line 4
Process 4
Line 4 is linked to Process 4
Line 5
Process 5
Line 5 is linked to Process 6
Line 6
Process 6
Line 6 became an available line
when it was unlinked from Process 6
Figure 5-2
Lines link to processes. In addition, lines can attach to a process. An unlinked
process is a phantom process and an unlinked line is an available line.
LIST-LINE-CHARS, or its synonym LLC, produces a report where the heading
LINE contains a listing of the characteristics of each line. The heading PROCESS,
contains an L for a linked process, an A for an attached process, an LA for a linked
and attached process and an a for an acquired process. Phantom processes do not
have an entry in this column.
The previous figure shows a set of seven lines and seven processes for a system.
There is a link between process 0 and line 0, process 1 and line 1, and process 2
and line 2. Normally, the system establishes all these links when you boot it. The
system unlinks line 3 from process 3 and attaches it to process 4. If you have
connected line 3 to a terminal, the terminal appears to be frozen because there is
no link to a process.
There is a link between process 6 and process 5. In order for this to happen, the
system unlinks process 5 from line 5 and process 6 from line 6, then it links
process 6 to line 5. Line 6 is an available line and process 7 is a phantom process.
5-10
A BASIC program running on process 4 could use SEND to output a message to
all lines except line 3. If line 1 was also attached by process 1, the program could
not output to line 1. Line 3 is the only line with input and output controlled
exclusively by process 4. Any process can send output to line 4 so it does not
control its own line exclusively.
While there is a link between process 4 and line 4 and an attachment to line 3, it is
possible to attach it to line 6 as well. In that way, it could control two lines
exclusively.
As another example, suppose there is a modem attached to line 6. CONVERSE
attaches a line to a modem and uses that line to communicate with another
computer system. If process 2 executes the following command:
>CONVERSE 6
all subsequent output passes through to line 6 and out to the modem. CONVERSE
takes care of attaching an available line to the process and detaching the line on
exit, automatically .
There is another way to control input and output at a terminal using TANDEM.
When you tandem another process, the current screen displays all input from that
process, and the resulting output simultaneously. TANDEM runs in two modes,
View mode and Feed mode. View mode allows you to observe the activity; while
Feed mode allows you to submit input to the process. This command is useful for
monitoring the activity of users for diagnostic or instructional purposes. Refer to
the UniVision Command Reference Manual for more information on TANDEM.
5-11
Section 6
THE UNIVISION CONTROL LANGUAGE
The UniVision Control Language Processor (UCL) is an interactive command
processor monitoring activity on a user's terminal. When a user logs on, they
communicate with the system using the UniVision Control Language (UCL). This
section covers the user's interactive environment, including the following topics:
•
Logging on and off.
•
Setting line and process characteristics.
•
User commands.
•
UCL Stacker.
Logging On and Off
A user must log on to the system to gain access to the UniVision Control
Language processor. The Logon processor monitors each communications line. It
displays a logon prompt and waits for user input.
To log on, a user must supply the name of the account and, usually, a password.
Invalid logon entries cause the system to display an error message and redisplay
the logon prompt.
The Logon processor must be able to find an Account Definition item in the
SYSTEM Dictionary that matches the account name entered at the logon prompt.
It must verify the password. Once the system verifies the account name and
password, the Logon processor sets up a pointer in the user's workspace to the
Master Dictionary for that account and normally passes control to the UCL
processor. In addition, the Account Definition item establishes the user's privilege
level and various account-level options.
The Logoff processor ends user sessions on the UniVision system. The user must
enter OFF at the UCL prompt or from the Debugger.
The UniVision Control Language
6-1
Restricting User Access
The system administrator sets the number of users that can log onto the system at
any one time using MAXUSERS. Once the number of users reaches this limit, the
system denies access to any additional users as they attempt to log on.
Sometimes, the system administrator might use MAXUSERS to prevent users from
gaining access to the system during a file-save.
It is possible to restrict access to an account to one or more selected processes.
You must specify the numbers of the processes permitted to log onto the account
as values in Attribute 12 of the Account Definition item.
The Logon Proc
The Logon Proc is a user-defined Proc with the same name as the account; and
stored in the Master Dictionary. The system executes this Proc when a user logs
onto the account, whether from the logon prompt or using LOGTO. In addition,
execution of the Logon Proc occurs on exiting UCL from the system, providing
that the user's Account Definition item has an R in Attribute 9.
The two main uses for a Logon Proc are:
•
to customise the computing environment for a user.
•
to invoke a user application automatically.
For instance, you can use this Proc to establish terminal and printer characteristics
for the session. You can insert TERM to set the terminal type. In addition, you can
use SP-ASSIGN to change the default printer assignment for the account.
For instance, the Master Dictionary for the account named 'SALES' contains the
following Proc:
PQ
HTERM 132,,,,1
P
Similarly, a Logon Proc could prompt a user to identify the type of terminal they
are working at, and set the terminal type appropriately.
Restricting Access to UCL
It is possible to use a Logon Proc to invoke an application automatically when a
user logs on and bypass the UCL level. However, that does not necessarily
prevent the user from exiting the program and getting to the UCL level. To deny
access to UCL:
•
6-2
Edit the user’s Account Definition item, placing a T in Attribute 9.
•
Create a Proc in the user’s Master Dictionary with the name of the
account followed by @TCL Thus, you create a Proc called STAFF@TCL
in the STAFF account.
•
Or create an @TCL Proc in the ERRMSG file. The system executes this
Proc only if an @TCL Proc does not exist in the Master Dictionary.
Usually, ERRMSG is a global file used by all users. This Proc should not
be account-specific.
If Attribute 9 of the Account Definition item contains 'T', and neither Proc exists,
the user exits to UCL. If the Proc does exist, the system executes it whenever the
user's process reaches a state where the UCL prompt would appear. This Proc
might present the user with a menu of various application-specific selections, or it
might simply execute OFF.
! Note:
If this Proc returns control to UCL, the system invokes it
repeatedly in a loop.
Receiving System Messages
On log on, the system might display a message it sends to all users of the system.
The system administrator creates these messages as a LOGON item in the system
ERRMSG file. For example, the administrator might need to notify users that the
system is closing down after 6 PM to perform routine maintenance. Thus, the
following message might appear:
****SYSTEM WILL BE DOWN FROM 6PM TO 7PM TONIGHT****
The LOGON item must exist in the ERRMSG file, even if there are no system
messages.
During a user session, the administrator or other users can send broadcast
messages using MSG or MESSAGE.
The Logoff Proc
The Logoff Proc is a user defined Proc having the same name as the account but
having a @ prefix and .OFF suffix. The system stores this Proc in the account’s
Master Dictionary.
For example:
@SALES.OFF
The system executes the Logoff Proc when a user logs off or when a user logs to
another account using LOGTO.
6-3
Logging to Other Accounts
You can use LOGTO to log to another account directly without logging off the
system. You must know the account name and password for that account. You
must supply the name of the account as a command-line parameter. The password
is an optional command-line parameter and the system prompts for it if required
and you have not supplied it.
For instance, the following command logs on to the STAFF account:
>LOGTO STAFF,GTY708
The system updates the account's usage statistics and displays them on the screen.
When s different account logs on the system maintains the UCL command stack
and tape attachment.
Logging Other Users On and Off
LOGON and LOGOFF provide a way to log on and off other users at other
processes. Both verbs are only available from accounts with SYS3 privilege.
You can use LOGON and LOGOFF to log terminals on and off, making them
available for a group of users, none of who actually log on or off the system. Such
terminals might run a program displaying a continuous listing of events at a
college, for instance. You can use LOGON and LOGOFF to run phantom
processes that do not require user intervention. To log on a remote process, enter
LOGON and the system displays the following prompt:
PROCESS,NAME
You must specify the process number followed by a comma, the account name
and, if required, a password. To log off a remote process, enter LOGOFF and the
system prompts for the process number. Both commands display a message
indicating that the operation was successful. In addition, you can use LOGOFF to
log off users who cannot quit their session normally by typing OFF at the
terminal.
Automatic Logoff
It is possible to enable automatic logoff for a process, causing the process to be
logged off the system after a specified period of keyboard inactivity.
AUTO-LOGOFF target [seconds] [(options[)]]
6-4
target
One of the following
account
Any account logged on to this process.
n
Process number
n-m
Range of processes
*
All processes
**
All account
***
All processes and accounts
seconds
Number of seconds of keyboard inactivity before the system
logs off the process automatically.
options
Can be one of the following:
C
Turns off automatic logoff for the specified target.
D
Monitors the incoming DTR signal for the
specified target and performs an automatic logoff
if it detects none.
Q
Enables Logoff and Quit from UniVision.
R
Redisplays the setting after an update.
The following example specifies that you want to log off process number 9
automatically after 600 seconds (10 minutes) of keyboard inactivity:
>AUTO-LOGOFF 9 600
For more details on automatic logoff refer to the UniVision Command Reference
Manual.
Setting Line and Process Characteristics
Communications line settings allow a user's terminal to communicate properly
with the system. In addition, each process has a number of default settings that
you can modify. Normally, you expect the line characteristics and the default
process settings to be correct, especially if the terminal has been connected to the
system and in operation on a regular basis. If they are not, however, it is fairly
easy to change these characteristics.
Communications Line Settings
Typically, the means of connection between a terminal and the system is a cable
running between a communications port on the computer system and a port on the
terminal. Two devices can communicate when both are using the same protocol.
6-5
At installation, the UniVision system establishes its default settings for a
communications line, as shown in Table 6-1. In addition, this table lists the
command used to change these settings.
Setting
Default
Command
Baud Rate
Parity
Bits
DTR
X-in
X-out
Echo
9600
NONE
8
OFF
ON
ON
ON
PROTOCOL
PROTOCOL
PROTOCOL
PROTOCOL
PROTOCOL
PROTOCOL
ECHO-ON/ECHO-OFF
Table 6-1: Default Line Characteristics.
As you can see you use PROTOCOL to change most of the communications line
settings. Refer to the UniVision Command Reference Guide for more information
on these commands and a description of each of these parameters.
! Note:
These defaults might be different at your site.
When you turn on the terminal and the system displays a stream of unfamiliar
garbage characters instead of a logon prompt, it could be that you have not set the
baud rate or parity properly. Baud rate, is the speed of transmission, and is usually
9600 for lines connected to terminals. Commonly you set modem lines at 300,
1200, or 2400, or even higher with more modern modems. These settings must be
the same at both ends. You should ask the system administrator for help in
establishing the correct line characteristics for your line.
Process Settings
There are a number of default settings established for each process on the system.
These settings define the state of the type-ahead buffer and provide or deny user
access to the UCL stack and the Debugger. Table 6-2 shows the default settings,
together with the command used to change the setting.
Setting
Default
Command
Type-Ahead Buffer
UCL Stack
ON
ON
Always on
STACK-ON/STACK-OFF
Debugger
ON
DEBUG-ON/DEBUG-OFF
Table 6-2: Default Process Settings
6-6
Once again, the defaults might be different on your system. For instance, end-user
applications usually disable <BREAK>, denying users access to the Debugger.
The Type-Ahead Buffer
Each process maintains a type-ahead buffer. The type-ahead buffer allows a user
to continue typing another command while the system is still processing a
previous command. In other words, the user does not have to wait for the UCL
prompt to reappear to begin typing. The type-ahead buffer collects user input and
processes it when the system is ready for it.
UniVision always enables the type-ahead buffer.
In addition, PROTOCOL has options that affect the operation of the type-ahead
buffer:
wrap
You can enter this option, but it has no effect.
bell
You can enter this option, but it has no effect.
C
When you specify C, the system clears the contents of the
type-ahead buffer.
Listing Line and Process Characteristics
LIST-LINE-CHARS lists the line characteristics for any or all lines on the system.
Entering LIST-LINE-CHARS (or its synonym LLC) at the UCL prompt produces a
report similar to the following:
LINE
0000
0001
0002
0003
0004
0005
0006
0007
0008
BAUD
9600
9600
9600
9600
9600
9960
9600
9600
9600
PARITY BITS DTR X- BELL
EVEN
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
NONE
7
OFF OFF ON
BUFFER
0
0
0
0
0
0
0
0
0
PROCESS
L 0000
L 0001
L 0002
L 0003
L 0004*
L 0005
TA- ECHO TANDEM
N/A OFF ON
N/A N/A
N/A N/A
N/A N/A
N/A ON BY 000
N/A N/A
L 0007
L 0008
N/A
N/A
N/A
N/A
This report lists the line and process characteristics for 9 lines. The asterisk for
line 4 in the PROCESS column indicates that line 4 generates the report. If you
want to list the line characteristics for a single line, you should specify the line
number as a parameter in LIST-LINE-CHARS. In addition, refer to LINEPROTOCOL.
6-7
Terminal and Printer Output Settings
TERM displays or modifies terminal and printer characteristics. Normally, you do
not have to change the standard settings. However, if the logon is from a different
type of terminal from the one normally in use, you might have to change these
settings. In addition, some terminals support a 132-character display, that you
might require on some occasions to preview reports sent to a line printer.
You use TERM to change the settings for the process for the current Logon
session. Do not use SET-TERM (in SYSPROG) to make the changes, as the
change affects the default settings for all users.
Entering TERM at the UCL prompt lists the current terminal and printer
characteristics.
>TERM
PAGE WIDTH
PAGE DEPTH
LINE SKIP
LF DELAY
FF DELAY
BACKSPACE
TERM TYPE
TERMINAL
79
24
0
1
5
8
V
PRINTER
132
60
Table 6-3 describes each of these settings:
Parameter
Default
Description
width
79
Number of characters per line on a terminal.
Must be in range 9 to 350.
depth
24
Number of lines displayed on the terminal
screen. Must be in the range 0 to 32767. 0
means no page breaks.
skip
0
Number of lines skipped at the bottom if the
terminal screen. The system subtracts skip
from page depth. Must be a number between 0
and 32767.
lf-delay
1
Number of null characters output after each
carriage return. Must be a number between 0
and 127. The delay characters provide a pause
for terminals that cannot displays characters as
fast as the CPU outputs them
Table 6-3: Specifying Terminal Setting with TERM
6-8
Parameter
Default
Description
ff-delay
5
Number of null characters output after a form
feed character for the terminal or printer. Must
be a number between 0 and 127.
If you specify 0, the system does not send a
form feed character to the terminal or printer at
the beginning of a page. If you specify 1, the
system sends a form feed (FF) character to the
printer, hexadecimal (0'C), CHAR912), but not
to the terminal. If you specify 2 or greater the
system sends the form feed character to both
the printer and terminal.
backspace
Taken from the UNIX parameters. It is a
number between 0 and 127.
ptr-width
132
Number of character per line for a printer.
Must be a number between 10 and 350.
ptr-depth
60
Number of lines on printer page. Must be a
number between 0 and 32767.
type
V
Terminal type code. The parameter changes
the form feed character to match the
requirements of the specific terminal and sets
cursor addressing for BASIC cursor functions.
Table 6-4 lists some terminal type codes.
Table 6-3: Specifying Terminal Settings with TERM (continued)
You must enter each of these parameters in the order shown above, each separated
by a comma. Consecutive commas indicate a null parameter, leaving the current
setting unchanged. The following command sets the line width to 132 and the
form-feed delay to 0:
>TERM 132,,,0
TERM does not return any message. You can verify the changes by entering TERM
again without any parameters.
Specifying the terminal type allows the UniVision system to send the proper
codes, as required by the terminal, to perform certain functions that control the
screen, such as form feeds, clearing the screen, and cursor addressing. The full
screen editor, UniWord, and BASIC programs that use @, use these functions
most often
Table 6-4 lists the default terminal types and the codes used to identify them.
6-9
Code
Description
A
B
I
J
M
P
Q
S
T
V
W
a
b
s
v
AT386
AT386-M
IBMPC
VT100
AMPEX
HP2621A
WYSE 50
ANSI Standard
TEC2402
VIEWPOINT Standard
VIEWPOINT Enhanced
at386
at386-m
ANSI standard
VIEWPOINT 132 col
Table 6-4: Terminal Type Codes
! Note:
The system terminal defaults and terminal types might be
different for your system installation. Check with your
System Administrator for any differences.
If the terminal you require does not appear in the list, check the manufacturer's
documentation to see if it is possible to set up the terminal to emulate any of the
terminals in this list. If not, refer to the UniVision System Administration Guide
for information on defining a new terminal type.
If type is the only parameter you want to specify, you can enter its value without
any preceding commas. For instance, if you were dialling into UniVision from a
personnel computer, you can use TERM to identify the terminal as type S, an
ANSI standard terminal:
>TERM S
This setting would remain in effect throughout the current logon session.
User Commands
There are two types of command a user can execute at the UCL prompt:
6-10
•
Verbs
•
Procs
The UCL processor looks in your Master Dictionary for the first word you type
and passes control to a system processor specified by the entry. The one exception
is UCL Stacker command set, that the UCL processor handles directly.
Verbs
Typically, verbs fall into the following categories:
UCL-I Verbs
These verbs do not access data files and typically
provide system information.
UCL-II Verbs
These verbs do access files, usually performing
common file management tasks.
VISION
These verbs access data files using the definitions
found in an associated dictionary.
Catalogued Programs
The verbs represent catalogued UniVision BASIC
programs, allowing users to invoke UniVision
BASIC programs without RUN.
It is useful to learn these categories because the syntax is similar for commands
found in each group.
Verb Syntax
The UCL statement consists of a verb, optional or required parameters, and
options enclosed in parentheses.
verb [parameters] [(options)]
The system does not interpret the statement until you press <RETURN> to submit
it. The verb must exist in the Master Dictionary of the account and the user must
have the appropriate privilege level to use the verb. Parameters comprise one or
more arguments supplied on the command line. These parameters might be a
filename, a single-letter, or a numeric value, as required specifically by the verb.
Parenthetical Options
One or more parenthetical options, specified on the command line, and enclosed
in parentheses. You only require the opening parenthesis. You can enter these
options, listed alphabetically below, in any order, and need not separated them
with spaces or delimiters. Where a comma is shown as part of the syntax, it is
optional.
Option
Function
C
Suppress default column and page headings, and end-of-list
message.
6-11
D
Suppress detail lines.
D
Delete original select-list (COPY-LIST).
E
Terminate selection process with <CTRL-X> or <ESC>.
F
Generate form feed.
H
Suppress page heading and end-of-list message.
I
Suppress item-IDs.
I
List item IDs (FIND)
L[,n]
Limit number of items selected.
N
Suppress pagination for terminal output.
O
Overwrite item (T-LOAD and COPY).
P
Direct output to printer.
Q
Suppresses the need to enclose item IDs and attribute values
in quotes.
R,[n]
Keep running count of item selected, n is the step; default is
1.
T
Direct output to the terminal (default).
X
Print data in hexadecimal format (COPY-LIST).
Y
Displays translation of DICT entries.
Not all options are available for all verbs. In fact, some options are specific to a
verb.
Verb Formats
Each user has their own verb vocabulary, based on verb entries in the account's
Master Dictionary. It is possible to expand or reduce the user's vocabulary by
adding or deleting entries in the Master Dictionary. Users can create synonyms for
existing verbs by making a copy of the entry under a new name.
! Note:
You should take care not to remove entries accidentally
or modify the contents of any verb entry.
Each verb has its own entry in the Master Dictionary. The format of these entries
is similar for all verbs, but it varies slightly according to whether the verb is a
UCL-I, UCL-II, or VISION verb, or a catalogued BASIC program. It is not
necessary to understand the format of verb entries. New users might want to skip
the remaining material in this section.
6-12
A P in Attribute 1 identifies a verb. It is possible to follow this letter by any letter
except a Q (Q indicates a Proc and PQX indicates a PQX/PQN Proc). In addition,
all verbs define a main entry point for a processor in Attribute 2. This entry point
is the location in hexadecimal of the executed code. Table 6-5 shows the format of
UCL-I verbs.
Attribute
Example
Description
0
TIME
Item ID: Unique identifier of verb in Master
Dictionary.
1
P
Identifiers: A P indicates a verb. Optionally
followed by a single character passed to the
processor.
2
2D
Processor's Entry Point.
Table 6-5: UCL-I Verb Format
UCL-II verbs are entries that have a '2' in Attribute 2. Table 6-6 shows the format
of UCL-II verbs. Attribute 2 parses the command line, verifies the filename, and
stores the location of the file in the process workspace. On completion the system
transfers control to the processor defined in Attribute 3. In addition, some UCL-II
verbs define a tertiary transfer point in Attribute 4 used as a branch routine by the
processor. Attribute 5 contains a parameter string passed to the processor.
Attribute
Example
Description
0
ED
Item ID: Unique identifier of a verb in
Master Dictionary.
1
P
Identifier: A P indicates a verb. Optionally
processor.
2
2
File Processor Entry Point: Defines entry
point for routine to parse command line for
file and validate filename and item ID.
3
3
Secondary Transfer Point: Defines transfer
point for processor to handle file and item
now specified in workspace.
4
Not Used
Tertiary Transfer Point: defines routine to
branch to routine above.
Table 6-6: UCL-II Verb Format
6-13
Attribute
Example
Description
Parameter String: These parameters
determine how UCL-II verbs retrieve and
pass items to the processor defined in
Attribute 3.
5
C
Copy item to process workspace.
F
Use file parameters only and ignore
item list.
N
Creating new items is permitted.
P
Printer item ID if item list ID '*@ or
if using a select-list.
Table 6-6: UCL-II Verb Format (Continued)
VISION verbs are entries that contain '35' in Attribute 2. Table 6-7 describes the
format of VISION verb entries. '35' references code in entry point hex 35 that
parses the VISION command line.
Attribute
Example
Description
0
LIST
Dictionary.
1
PL
Identifiers: A P indicates a verb. Optionally
processor. In this case L indicates LIST
2
2
Processor's Entry Point: Defines entry point for
routine to parse VISION command line.
Table 6-7: VISION Verb Format
Catalogued UniVision BASIC programs have entries in the Master Dictionary
referencing the entry point of the UniVision BASIC Runtime package and the
name of the file containing a pointer to the location of the object code. Table 6-8
describes the format of entries for catalogued programs.
Attribute
Example
Description
0
FX
Dictionary.
Table 6-8: Catalogued Program Verb Format
6-14
Attribute
Example
Description
1
P
Identifiers: A P indicates a verb.
2
E6
Processor's Entry Point: Defines entry point for
UniVision BASIC Run-time Package.
3
Not Used
4
Note Used
5
BASICLIB
Program File: This is the name of the file, whose
dictionary contains a pointer to the object code.
Table 6-8: Catalogued Program Verb Format (Continued)
UCL-I Verbs
UCL-I verbs are a set of general purpose verbs that do not require the user to
specify the name of file. These verbs can access various system files to get
information, but the user does not need to identify the file. In general, these verbs
do not support parenthetical options, except where specifically allowed. The
following is a list of some UCL-I verbs:
BLOCK-PRINT
Displays a character string using block letter definition in the
BLOCK-CONVERT Dictionary.
DUMP
Lists the contents of one or more frames.
ECHO
Controls whether the system echoes user input on the screen.
MSG or MESSAGE
Send a message to users of a specified account or line, or to
all users or all lines.
P
Suppresses or permits, toggle, output to terminal.
SLEEP
Suspends a process for a specified number of seconds or
until a time-of-day specified.
TERM
Sets and displays terminal and printer settings.
TIME
Displays the current time and date.
WHO
Displays the user process numbers and account names.
>>
Enters a multi-command execution level without entering the
Debugger.
<<
Exits from a multi-command execution level without
entering the Debugger.
6-15
A set of UCL-I verbs define the user environment:
DEBUG-ON
Enables the use of the Virtual Debugger and the UniVision
BASIC Debugger for a particular process.
DEBUG-OFF
Disables use of both Debuggers.
ECHO-ON
Enables echoing by the operating system of all character
entered by user.
ECHO-OFF
Disables echoing of user input.
STACK-ON
Enables the UCL Stacker.
STACK-OFF
Disables the UCL Stacker.
In addition, there are verbs that perform various arithmetic functions:
ADDD
SUBD
MULD
DIVD
Performs addition, subtraction, multiplication and division
on pairs of decimal numbers.
ADDX
SUBX
MULX
DIVX
Performs addition, subtraction, multiplication and division
on pairs of hexadecimal numbers
DTR
DTX
Converts decimal to another radix. Default is hexadecimal.
RTD
XTD
Convert hexadecimal to another radix. Default is decimal
The preceding lists of UCL-I verbs include only those used most commonly verbs.
Refer to the UniVision Command Reference Guide for a complete description of
the use of all verbs.
UCL-II Verbs
UCL-II verbs are commands that access files. You must supply the name of the
file together with a list of one or more item IDs. The general form of the syntax is:
verb [DICT] filename [item-list|*] [(options)]
st
The name of a file must follow the verb immediately as the 1 parameter on the
command line. The DICT modifier specifies the dictionary of the file.
An item list is a list of individual item IDs, each separated by a blank space or
surrounded in quotes. You can specify an asterisk in place of an item list to
indicate all items in the file. If an item ID contains blanks or parentheses, you
must surround it with single quotes. The item list is optional when a select-list is
available.
6-16
A list of some general-purpose UCL-II verbs follows:
COPY
Copies selected file items to another file, the terminal or the
printer, or copies an item to a new item in the same file.
RENAME
Changes the name of a file.
DOC-EDIT or DE
Invokes the screen-oriented Editor.
EDIT or ED
Invokes the line-oriented Editor.
FIND
Selects items in a file containing a specified string.
GROUP
List file item statistics for an item's group.
NSELECT
Uses a current select-list to search a file and creates a selectlist containing items not found in the file
PRINT-ERR
Invokes System message processor.
QSELECT
Creates a select-list containing data from specified attributes
instead of item IDs.
VISION Verbs
It is possible to think of VISION verbs of as UCL-II verbs that support an
extended syntax. These verbs include LIST, SORT, and SELECT.
In addition, VISION verbs require a filename and accept an item list. The
st
filename can appear in any position on the command line except the 1 . In
addition, these verbs allow you to specify output criteria as well as modifiers and
connective. Refer to the Section entitled VISION Syntax the VISION Reference
Guide for a complete description of the syntax of VISION verbs.
Procs
Procs are stored procedures interpreted by the PROC processor. You define Procs
as PQ or PQX items in the Master Dictionary and often as items in a user's Proc
library. The system uses the global file, UVPROCS, to store system Procs. The
Master Dictionary contains a pointer to the UVPROCS file and each Proc points
to an item in that file. The following shows the CT Proc in the Master Dictionary:
CT
001 PQ
002 (UVPROCS CT)
A number of standard Procs are available in an account including:
6-17
CT
Copies one or more items from file to screen. Invokes
COPY.
LISTCONN
Displays a sorted list of the connectives available in the
account. Invokes SORT.
LISTDICT
Displays a sorted list of the Attribute Definition items in the
Master Dictionary or any file dictionary. Invokes SORT.
LISTFILES
Displays a sorted list of File Definition items in the master
Dictionary or any file dictionary. Invokes SORT.
LISTPROCS
Displays a sorted list of Procs in the Master Dictionary or
any specified file dictionary. Invokes SORT.
LISTVERBS
Displays a sorted list of verbs in UVPROCS or any specified
file dictionary. Invokes SORT.
Catalogued UniVision BASIC Programs
You can execute UniVision BASIC programs catalogued in an account as userdefined verbs. These verbs might invoke user applications software for word
processing or spreadsheets. The BASICLIB and UVPROCS files, contain a few
sample UniVision BASIC programs. In addition, other programs might be
available in your account.
You must catalogue UniVision BASIC subroutines in an account to enable
programs to call them. You do not have to catalogue the calling program.
UCL Stacker
The UCL Stacker maintains a stack of previous commands entered by the user. In
addition, Procs and UniVision BASIC programs can add to the stack. The default
size of the stack, or the number of statements stored, is 20.
The system pushes each new command on top of the stack. For instance, once the
system executes WHO, it goes on to the stack as statement 1.
1
WHO
nd
Entering another command pushes WHO into the 2 position. Entering TIME, for
example, places TIME in the top position.
1
TIME
2
WHO
The system now refers to WHO as statement 2. Each time you enter a statement the
system pushes all previous statements down to make room for the new statement
at the top.
6-18
1
TERM V
2
TIME
3
WHO
If entering a new command causes the stack size to exceed 20, the system
removes a statement from the bottom of the stack.
You can retrieve, execute and save any statement in the UCL stack from the stack
using a few basic commands. UCL Stacker commands begin with a (.) and consist
of a single letter. The stack does not store UCL Stacker commands.
.? lists a summary of the UCL Stacker commands.
Enabling the UCL Stacker
Normally, you enable the UCL for an account. You can disable it using STACKOFF and enable it using STACK-ON.
If you disable the UCL Stacker, the system attempts to interpret stack commands
as verbs and produce an error message.
Referencing Other Processes
It is possible to use all UCL Stacker commands with a few exceptions to reference
a stack belonging to another process, providing the user has SYS2 privileges.
Thus, you can retrieve, modify and execute statements from another user's stack,.
The syntax for this option is to place the process number in parentheses.
For instance, the UCL Stacker command:
>.L5 (2)
Lists the top five statements in the stack of process 2.
There are several commands that do not accept this option: .A, and .M modify the
top statement in your stack only; .K does not allow you to delete statements from
the stack of another process; and .R reads an item into the current stack only.
In addition, .Q, .S, and .Z accept the parameter '(A)' specifying that the command
affects all processes.
Listing the Stack
.L displays all or some if the statements stored in the stack currently. By default,
the system displays the first 20 statements in the stack. This command takes one
or two parameters as follows:
.L[n[,m]][(process)]
6-19
n
specifies the number of statements to display. If you do not
specify a value, .L uses the last value specified for n. By
default, .L displays 20 statements.
m
specifies the number of the statement from which the display
begins. If you do not specify a value, .L begins the display
with the first statement in the stack, the statement entered or
executed most recently.
process
number of a process other than your own. This option allows
you to list statements in the stack of a specified process. You
require SYS2 privileges to use this option.
! Note:
The number of statements listed is independent of the
number of statements stored in the stack, as set by .S.
Executing Previous Statements
It is possible to re-execute any statement from the stack. .X without any
parameters executes the top statement in the stack, the last statement entered. In
addition, the command accepts parameters as follows:
.X[n[,m,...]][(options)]
n
number of the stack statement you want to execute. Default
is 1.
m
number of each additional stack statement you want to
execute. Use commas, without spaces, to separate the
statement numbers. .X displays and executes the statements
in the order specified.
options
number of process other than your own. This option allows
you to execute statements from the stack of the specified
process. You require SYS2 privileges to use this option.
The system displays the statement before executing the command. The system
does not duplicate the command on the stack unless n equals m.
! Note:
After the system re-executes a stack statement, it moves
it from its original position to the top of the stack.
Modifying Previous Statements
There are a number of ways to modify commands in the stack:
6-20
.E
Edit statements in the stack.
.M
Modify top statement by replacing specified text.
.A
Append text to top statement in stack.
Because the last two commands affect only the top statement in stack, you often
use them after .G to get any command in the stack and bring it to the top.
All of these commands affect the contents of the stack; however, they do not
execute the modified statements. You must do this explicitly, using the UCL
Stacker execute command, .X.
Editing the Stack
.E invokes the system Editor to edit the statements in the stack. The system treats
each statement as a separate line, like an attribute in a file item. This command is
useful for modifying more than one statement in the stack.
.E[n][(process)]
n
number of the statement in the stack. If you do not specify a
number, .E positions the current line pointer at line 1.
process
number of a process other than your own. This option allows
you to edit statements in the stack of the specified process.
You require SYS2 privileges to use this option.
Choosing a Command to Modify
.M and .A can operate only on the top statement in the stack. You use .G to
retrieve any statement in the stack and place it on top. .G requires a single
parameter, the number of the statement you want to move. The system moves the
specified statement from its previous position, and renumbers all statements
accordingly.
Replacing Text
.M modifies the top statement in the stack. It allows you to perform a search-and
replace operation on the line. The syntax is:
.M[U]/text1/text2[/]
U
changes all occurrences of text1 to text2. Use this option if
text1 appears more than once in the statement.
text1
text string in statement you want to replace.
text2
text string you want to substitute for text1.
The following examples show two uses of .M to edit a single command line. The
st
1 use is an example of making multiple replacements on a one line using U.
Without U, the system only changes the first occurrence of NAME to LAST-NAME.
nd
The 2 use is an example of a single replacement.
6-21
>.L1
001 LIST CUSTOMERS WITH NAME EQ SMITH NAME PHONE
>.MU/NAME/LAST-NAME/
LIST CUSTOMERS WITH LAST-NAME EQ SMITH LAST-NAME PHONE
>.M/SMITH/"SMITH"/
LIST CUSTOMERS WITH LAST-NAME EQ "SMITH" LAST-NAME PHONE
The search pattern must contain at least one character. Remember that the search
string need only consist of as many characters that identify the text you want to
replace uniquely.
You can use any non-numeric character as the delimiter in place of the slash (/).
You might use a different delimiter, such as *, when either the search or
replacement string contain a slash.
Appending Text
.A appends text to the end of the top statement on the stack. The syntax is:
.A text
You must separate the specified text from .A by one space. As you often use this
command to append parameters to a statement you will find that the text string
must also begin with a space. For example, to append BY LAST-NAME to an
VISION statement, you would specify:
.A__BY LAST-NAME
st
nd
where _ represents a single space. The 1 space serves as a delimiter; the 2 space
is part of the text string you want to append.
Storing a Series of Statements
.C invokes the COPY processor to copy statements from the UCL stack to an item
in a file. You can store multiple statements as a single file item. The syntax is:
.Cn [,m,... [(options)]
6-22
n
number of the statement in the stack you want to copy.
m
number of one or more additional stack statements you want
to copy to a file item.
options
list of options that modify the operation. Enclose the options
in a set of parentheses.
process
process number of a process other than your own.
This option allows you to copy statements from
the stack of the specified process. You require
SYS2 privileges to use this option.
A
copies all stack statements.
O
overwrites existing file item.
P
copies to printer.
T
copies to terminal
X
copies in hexadecimal.
Because .C invokes the COPY processor, the system displays the standard COPY
prompt to identify the name of an item. By default, the system copies the
statements to the Master Dictionary. To specify another file, enter the filename,
preceded by an opening parenthesis and followed by a closing parenthesis or a
space, and the item ID.
The following example shows saving the top two statements in the stack as an
item in the Master Dictionary. Use CT to list the new item to show the order in
which the system stores the statements.
>.L2
001 LIST CUSTOMERS
002 QSELECT ORDERS * (1)
>.C2,1
TO : CUST.ORDER.LIST
1 TO CUST.ORDER.LIST
1 ITEM COPIED
>CT MD CUST.ORDER.LIST
CUST.ORDER.LIST
001 QSELECT ORDERS * (1)
002 LIST CUSTOMERS
>
You might create a file specifically for storing items created from the command
stack. Using such a file makes it easier to locate and maintain these items. For
example, the following command:
.C3,5,6
TO:(TC REPORTS)
6-23
copies statements 3, 5, and 6 from the stack to the item 'REPORTS' in the file
'TC'. When the TO: prompt appears, pressing <RETURN> displays the list of
commands on the screen. If you specify a filename, you must specify an item ID
as well.
Retrieving an Item
.R reads the contents of any item containing valid UCL statements, executes them
in sequence, and places them on the stack. Typically .R retrieves items created
using .C.
Its syntax is:
.R [DICT] filename [item-ID] [(L)]
DICT
specifies the file dictionary
filename
name of the file.
item-ID
identifies the item in filename containing the stored
statements you want to execute.
L
load statements in item-ID into the stack without executing
them
Each attribute in the specified item must contain a valid UCL command. The
system places statement 1 on the stack and executes it, then it pushes the next
statement on the stack and executes it.
You can incorporate any UCL stacker command in a Proc. For example:
001
002
003
004
005
PQ
C DO ITEM-ID : RUN IDENTIFIED PROC FOUND IN TC FILE
H.R TC
A2
P
.R is completely recursive; it can execute items containing .R commands that, in
turn, executes the statements in other items.
Deleting Statements from the Stack
.K deletes, kills, any statement from the stack. The syntax is:
.Kn
n
number of the stack statement you want to delete.
You can only delete one statement at a time from the stack. When you delete a
statement, the system renumbers the statements preceding it in the stack. Thus, if
you want to delete several consecutive statements, delete them in reverse order.
6-24
Setting UCL Stacker Options
There are a number of commands used to change the operation of the UCL
Stacker. These commands toggle the current state. You require SYS2 privileges to
uses these options.
.O
Disables or enables the UCL Stacker. Used to disable the
commands in the stack storage temporarily.
.P
Disables or enables Proc command storage. By default, Proc
command storage is ON. When you execute a Proc from
UCL, the system places the name of the Proc and the
statements it executes on the stack. When disabled, the
system only places the name of the Proc on the stack.
.U
Enables or disables upper-case conversion. Normally, the
system places commands on the stack exactly as you enter
them. When you enable upper-case conversion, the system
converts all statements to upper-case before placing them on
the stack. The system does not convert literals. Only requires
SYS0 privileges.
.Sn
Set the maximum number of statements stored in the stack to
n. The default is 20.
.Zc
Assign c as the UCL delimiter. ESC is the default delimiter
of UCL statements. Use this command to specify a new
delimiter. Only requires SYS0 privileges.
Normally, you use all of these commands to change the state of your own process.
If you have SYS2 privileges, you can change the state for any other process by
specifying the process number in parentheses. In addition, .Z and .S allow you to
change the UCL delimiter and stack size for all processes by specifying A.
You can examine the status of all of the UCL Stacker options using .Q (query). Its
syntax is:
.Q [(A|process)]
.Q lists the UCL Stacker options for your process. A lists the status of the UCL
Stacker options for all users. Specifying process lists the status of the UCL
Stacker options for the specified process. You require SYS2 privileges to use
these options.
An example of the report generated by .Q follows:
>.Q
User#
4
Stack
20
#Cmnds
25
Page
2
.O
ON
.P
OFF
.U
OFF
UCL Delim
([) X’RFB’
6-25
The report has the following format:
6-26
User#
line number of the user's terminal.
Stack
maximum length of the stack, as set by .S. Default is 20.
#Cmnds
number of commands stored in the stack.
Page
number of stack commands displayed, as set by .L.
.O
indicates whether the UCL Stacker is enabled or disabled.
.P
indicates whether Proc command storage is enabled or
disabled.
.U
indicates whether upper-case conversion is enabled or
disabled.
UCL Delim
shows in parentheses the character used for the UCL
delimiter as set by .Z, followed by its equivalent hexadecimal
value.
Section 7
FILE MANAGEMENT
This section provides an overview of managing files on the UniVision System. It
covers the following topics:
•
Creating and deleting files.
•
Copying items from files.
•
Creating Q-pointers to reference files in other accounts.
•
Establishing file security procedures.
•
Performing routine file maintenance to ensure retrieval efficiency.
•
Understanding backup and restoration procedures.
File Management Tasks
UniVision provides a number of system commands for managing files and
manipulating the items contained in files. You use these commands to create, edit,
copy, delete, and clear files.
The file management commands are:
CREATE-FILE
Creates new dictionaries and data files in an account by
allocating the file's primary space.
RENAME
Changes the name of the dictionary portion of a file, the data
portion of the file, or both the dictionary and data portions.
MOVE-FILE
Transfers file between accounts.
CLEAR-FILE
Clears the file area occupied by the data file or dictionary. It
does not de-allocate the primary space, as does DELETEFILE. In addition, it releases any linked frames, returning
them to the overflow area.
DELETE-FILE
Deletes the file dictionary, the data file, or both, from the
account. All frames allocated for the file are released.
File Management
7-1
! Note:
It you delete a dictionary file you must have deleted the
data files associated with this dictionary before
attempting to delete it.
EDIT or ED
Creates modifies, or deletes individuals items in a file. EDIT
(or ED) is a line-oriented editor based on the standard Editor,
and DOC-EDIT (or DE) is a full-screen editor.
COPY
Copies selected file items to another file, the printer or the
terminal, or copies any item to a new item ID in the same
file.
DELETE
Deletes specified items from a file.
Filename Syntax
All the file management commands are UCL-II verbs. All recognise the same
syntax for specifying a file.
You must define the specified file in the Master Dictionary of the account. Each
data file must have as its counterpart a dictionary file describing the nature of the
data. You can think of each file of as having two sections: a data section and a
dictionary section. Both the dictionary and the data file contain items.
When the dictionary and the data file have the same name, you only need to
specify the name of the data file. When you supply a filename, the system looks in
the account's Master Dictionary for a File Definition item of the same name
identifying the dictionary. It then looks in the file dictionary to find a File
Definition item pointing to the data file. For example, when you specify the
filename 'CUSTOMERS', the name of the dictionary is 'CUSTOMERS' and the
name of the data file is again 'CUSTOMERS'.
You can use file management commands to access the data file or the file
dictionary independently. The following modifiers precede the filename:
DATA
A modifier specifying that only the data file is the target of
processing.
DICT
A modifier specifying that only the dictionary is the target of
processing.
'DICT CUSTOMERS', for instance, refers to the dictionary of the CUSTOMERS
FILE.
If multiple data file share a dictionary, you can access each data file independently
of the other data files associated with the dictionary. If the name of the data file
you want to access is different from the name of the dictionary, you must specify
the name of the dictionary followed by the name of the data file. A comma, with
no spaces on either side of it, must separate the name of the dictionary from the
name of the data file. In the following example:
7-2
PERSONNEL,DAY-SHIFT
The syntax indicates that DAY-SHIFT is a data file associated with the dictionary
PERSONNEL.
A dictionary can exist without a data file, this is a single-level file. The dictionary
contains a Q-pointer that references itself, indicating that the items in the
dictionary are the target of any operation. The Master Dictionary is a single-level
file, which is why you do not have to specify 'DICT MD' to access it. On the other
hand, a data file cannot exist without an associated dictionary file.
Item Lists
Some of the file management commands (COPY, ED and DE) accept an item list.
st
An item list indicates one or more items you want to process in the file. The 1
form of an item list is a string of item IDs with each item ID surrounded by single
or double quotes or separated from the next item ID by a space. An example of a
list of three item IDs is:
'10118' '10119' '10121'
nd
A 2 form for specifying an item list is by an asterisk (*). This indicates that you
rd
want to process all items in the file. A 3 way to specify an item list is to generate
a select-list before invoking the file management processor. You use the select-list
as the item list for the command. You use SELECT, SSELECT, QSELECT or
GET-LIST to make a select-list active. Refer to the Section entitled Statement
and Function Reference in the VISION Reference Guide for more information on
working with select-lists.
Creating Files
You use CREATE-FILE to create:
•
a dictionary file.
•
a data file and its associated dictionary.
•
a data file only, if a dictionary already exists with the same name.
•
a file using the B+Tree hashing algorithms.
The syntax for creating a file is:
CREATE-FILE {filnam|dicnam,datnam} dicmod datmod [(R)] [(options]
CREATE-FILE DICT filnam mod [(R)] [(options]
CREATE-FILE {filnam}{dicnam}{datnam} (B[J] [(options]
CREATE-FILE DATA filnam mod [(R)] [(options]
File Management
7-3
filnam
name of the file
dicnam,datnam
full name of the file. Use this format to create a data file that
is one of multiple files associated with a single dictionary.
dicmod
modulo value of the dictionary
datmod
modulo value of the data file
DICT
DATA
specifies the data file
mod
modulo value of the dictionary or data file
R
creates a file in a target account.
B
creates a file using the B+Tree hashing algorithm with leftjustified identifiers.
BJ
creates a file using the B+Tree hashing algorithm with rightjustified identifiers.
options
one of the following:
X
creates a DX file, which means you cannot save
the file.
Y
creates a DY file, which means you can save the
file, but not the data.
Creating a Dictionary
>CREATE-FILE DICT INVENTORY 3
[417] UniVision File 'INVENTORY' Created; Base=10074, Modulo=3.
Creates a dictionary called 'INVENTORY', allocating 3 frames for it, and placing
a D-pointer of the same name in the Master Dictionary.
If, subsequent to the creation of the dictionary, you do not create a data file, the
dictionary is a single-level file that contains a Q-pointer to itself. This is called a
reflexive Q-pointer, containing no information in Attributes 2 and 3 of the entry.
Creating a Data File
A dictionary must exist before you attempt to create a data file.
7-4
When you create a data file, CREATE-FILE allocates the data file's primary file
space. The system creates a File Definition item in the associated dictionary. This
D-pointer identifies the data file and contains the base frame ID and modulo. The
dictionary has File Definition item for each data file that it points to. For example:
>CREATE-FILE DATA INVENTORY 373
[417] UniVision File 'INVENTORY' Created; Base=10077, Modulo=373.
Creates the data file 'INVENTORY', allocating a block of 373 frames for it, and
placing a D-pointer of the same name in the file dictionary named 'INVENTORY'.
Creating a New Database
It is possible to create a dictionary and data file at the same time.
This usage requires you to specify the modulo of the dictionary and the modulo of
the data file. This form of CREATE-FILE performs the creation of the dictionary
followed by the creation of the data file in a single step. If you want multiple files
st
to share the dictionary, you can only use this syntax to create the 1 data file. You
only specify the name of the dictionary if you do not want it to have the same
name as the data file.
>CREATE-FILE SHIPPING 3 373
[417] UniVision File 'SHIPPING' Created; Base=10450, Modulo=3.
[417] UniVision File 'SHIPPING' Created; Base=10453, Modulo=373.
Creates a dictionary named 'SHIPPING', allocating 3 groups for it, and placing a
D-pointer in the Master Dictionary. In addition, it creates the data file
'SHIPPING', allocating 373 groups for it, and placing a D-pointer in the
SHIPPING dictionary.
The following example creates a dictionary and a data file with different name:
>CREATE-FILE PERSONNEL,DAY-SHIFT 3 37
[417] UniVision File 'PERSONNEL 'Created; Base=10826, Modulo=3.
[417] UniVision File 'DAY-SHIFT Created; Base=10829, Modulo=37.
This command creates the dictionary 'PERSONNEL', allocating 3 groups for it. In
addition, it creates the data file 'DATA-SHIFT' allocating 37 groups for it.
The Master Dictionary has a D-pointer for the dictionary PERSONNEL which has
the D-pointer to the data file 'DAY-SHIFT'. The Master Dictionary does not have
any reference to DAY-SHIFT. To create another data file associated with the
PERSONNEL dictionary, you would enter the following:
File Management
7-5
>CREATE-FILE DATA PERSONNEL,NITE-SHIFT 37
[417] UniVision File 'NITE-SHIFT' Created; Base=10867, Modulo=37.
This command creates a data file name 'NITE-SHIFT', placing a D-pointer in the
PERSONNEL dictionary.
Creating a File in a Target Account
>CREATE-FILE ORDERS 3 3 (R
ACCOUNT NAME: SYSPROG
Creates a file in a target account, creates the file ‘ORDERS’ and stores the pointer
for that file in the account SYSPROG.
Creating UniVision BASIC Files
You use CREATE-BFILE to create a UniVision BASIC program file. The system
creates the source code for a UniVision BASIC program as an item in the data
file; when you compile the source file, the system places an item in the file
dictionary pointing to the location of the object code. CREATE-BFILE has the
same basic syntax as CREATE-FILE.
>CREATE-BFILE BP 3 37
[417] UniVision File 'BP' Created; Base=10904, Modulo=3.
[417] UniVision File 'BP' Created; Base=10907, Modulo=37.
CREATE-BFILE performs the same function as CREATE-FILE except that it
creates a File Definition item in the Master Dictionary with a Definition Code of
'DC'. This indicates to the system that the file dictionary contains items pointing to
the location of complied UniVision BASIC object code.
In addition, it is possible to use CREATE-FILE for this task, providing you change
the Definition Code of the D-pointer in the Master Dictionary from 'D' to 'DC'.
Clearing a File
CLEAR-FILE clears data from a file. You use it when you want to discard the
contents of a file yet want to maintain the primary file space for future use.
CLEAR-FILE sets the file to an empty state by placing a segment mark in the first
data position of each group. The system releases any additional frames linked to a
group. The system returns these frames to the overflow area. Thus, by clearing a
file, the system reduces it to the space originally allocated for it.
CLEAR-FILE clears either the dictionary of the data file. It is not possible to clear
both files with a single command. The syntax is:
7-6
CLEAR-FILE DATA {filnam|dicnam,datnam}
CLEAR-FILE DICT filnam
DATA
specifies the data file.
DICT
filnam
name of the file.
dicnam,datnam
full name of the file. Use this form to clear a data file that is
one of multiple files associated with a single dictionary.
Clearing a file does not change the disk space allocated for the file originally;
however, it returns any additional frames linked to the file to the available space.
>CLEAR-FILE DATA SHIPPING
clears all items from data file SHIPPING. This command does not return a
message when successful.
Deleting Files
You use DELETE-FILE to delete:
•
a dictionary and its associated data files.
•
any data file.
•
any dictionary, provided you have deleted the data files associated with
the dictionary before attempting to delete it.
DELETE-FILE removes the D-pointer referencing the file and releases the frames
occupied by the file. Obviously, you should use any command that removes data
from the system with extreme caution. You should only remove files for which
there is a backup.
DELETE-FILE does not delete files referenced by Q-pointers. You can delete only
files referenced by D-pointers. You can delete the File Synonym item in the
Master Dictionary (using DELETE), but cannot delete the file itself. In fact, you
should remove all Q-pointers to a file you want to delete, as those synonyms no
longer point to a valid file.
The syntax is:
DELETE-FILE filnam
DELETE-FILE DICT filnam
DELETE-FILE DATA {filnam|dicnam,datnam}
filnam
name of the file you want to delete.
DATA
specifies the data file.
File Management
7-7
DICT
dicnam,datnam
full name of the file. Use this format to delete a data file that
is one of multiple files associated with a single dictionary.
If you do not specify modifiers, filnam identifies the file dictionary and all of its
associated data files. For example, if PERSONNEL is a dictionary shared by two
data files.
>DELETE-FILE PERSONNEL
deletes the dictionary and both of the data files. The system does not return a
message when the command finishes successfully.
If you only want to delete one of the data files, you could use the following
command:
>DELETE-FILE DATA PERSONNEL,NIGHT.SHIFT
The system removes the D-pointer 'NIGHT.SHIFT' in the PERSONNEL
dictionary and returns the space occupied by the data file to the overflow area.
You use the DICT modifier to delete a file dictionary. You cannot delete just the
dictionary if it contains any D-pointers. In other words, you must delete all of its
associated data files before you can delete the dictionary. You use the DATA
modifier to delete a single data file. If the data file and the file dictionary do not
have the same name, you must specify the dictionary name.
Copying File Items
You can use COPY to copy:
•
one or more items to other items in the same file, assigning new item
IDs.
•
Any or all items in a file to another file, using the same item ID or assign
new ones.
In addition, you can use COPY to display the contents of one or more items on the
screen or printer. In addition, CT invokes a COPY, CT copies the contents of an
item to the screen or printer.
A copy operation involves a source and a destination. COPY requires you to
specify the source on the command line and prompts you for the destination. The
command-line syntax is:
COPY [DICT] filnam item-list [(options)]
7-8
DICT
filnam
name of the source file containing the original item or items.
This must exist on the current account
item-list
list of item IDs you want to copy, separated by blanks. Use
double quotes to enclose item IDs that have embedded
blanks. An asterisk (*) specifies all items.
options
modify COPY. Enclose the options in parentheses and
separate the options with a comma.
The following options are available for specifying the target
destination of the copied items:
P
copies data to the line printer.
T
copies data to the terminal. In addition, you can
use CT to copy items to the terminal.
The following options are available for copying items or files
to other items or files;
D
deletes the source item after copying it.
I
does not list item IDs after copying them.
N
does not copy an item to the target file unless an
item with the same name already exists there.
O
overwrites items in the target file it they already
exist there
S
suppresses error messages.
The following options are available for copying items or files
to a printer or terminal.
F
inserts a form feed between each item.
N
skips the automatic end-of-page wait.
S
suppresses line numbers.
X
displays data in hexadecimal form.
COPY displays the prompt TO: where you enter the destination, using the
following syntax:
{item-list|([DICT] filnam )}[item-list]
File Management
7-9
DICT
specifies a file dictionary. When copying from a dictionary,
COPY does not copy dictionary items that have a definition
code of D (File Definition items)
filnam
name of the destination file, enclosed in parentheses. This
file must exist on disk.
item-list
list of item IDs to be assigned in sequence to the copied
items. Use blanks to separate the item IDs, and use double
quotes to enclose any item ID with embedded blanks. If you
omit this item-list, the system uses the item IDs in the source
file. If you are copying the items to the same file, the item
IDs cannot be the same as those for existing items, unless
you are using the O option.
If you have not specified any of the above parameters, pressing <RETURN>
causes the system to display the source items on the screen. If you only specify an
item-list, the source file and the destination file are the same. The system copies
items to the same file, using the item IDs specified in the item list. The following
example creates a duplicate of the item 'LETTER-JOHN' in the file
'DOCUMENTS'; the duplicate has the item ID 'LETTER-JAMES'.
>COPY DOCUMENTS LETTER-JOHN
TO:LETTER-JAMES
1 LETTER-JOHN TO LETTER-JAMES
1 Items copied
Following the copy operation, the DOCUMENTS file contains both 'LETTERJOHN' and 'LETTER-JAMES' items.
You require a left parenthesis before a filename that is the destination of the copy
operation. A right parenthesis after the filename is optional. If you specify a file
and an item list, the system copies the source items to the destination file using the
item IDs specified in the destination item list. You cannot copy File Definition
items in a dictionary to another file. If you do not specify a destination item list,
the system copies the source items using the same item ID. The following
example copies two items from the file 'ORDERS' to the file 'ORDERS,PAID':
>COPY ORDERS 10123 10124
TO:(ORDERS,PAID)
1 10123
2 10124
2 Items copied
After the copy operation, both files have items '10123' and '10124'. On a file copy,
the system displays the item ID of each item copied. (The I option suppresses the
display of item IDs).
7-10
During a file copy operation, you can specify the source file item list using an
asterisk (*), indicating that you want to copy all items to the destination file. If the
source is a dictionary file, the system copies all items except D-pointers.
If the item ID in the destination file, the system displays the following message:
[415] 'item' exists on file.
0 Items copied
Use the O option to overwrite all items specified on the destination item list.
The N option used with the O option restricts the operation to overwriting existing
items. This option specifies that a file copy operation should succeed only if the
item already exists in the destination file. It ensures that the system does not create
new items in the destination file.
Use the D option on a file copy operation to delete the source file item once the
system has copied it to the destination file. In the following example:
>COPY ORDERS '10103' (D)
TO:(ORDERS,PAID)
1 10103
1 Items copied
The system copies item 10103 to the ORDERS,PAID file, and then deletes it from
the ORDERS file.
Editing Items
UniVision provides two editors you can use to create and modify items in a file.
An editor performs the bulk of file management tasks on UniVision from editing
items in the Master Dictionary or the file dictionary to creating items in the data
file. You can create, copy, merge, modify or delete one or more items in a file
using an editor.
EDIT (or ED) invokes the line-oriented Editor. DOC-EDIT or DE invokes the
screen-oriented editor. The syntax for invoking either editor is:
ED[IT]|D[OC ]E[DIT] [DICT] filnam [item-ID] [(options)]
DICT
filnam
name of the file containing the items you want to edit.
item-ID
list of items you want to edit. The list can include a
UniVision BASIC program as well as items in either a
dictionary or data file. It is possible to enter multiple item
IDs. An asterisk (*) specifies all items in filename.
File Management
7-11
options
H
displays data in hexadecimal format. (ED and
EDIT only).
L
displays line numbers. (DE and DOC-EDIT).
S
suppresses the display of line numbers. (ED and
EDIT only).
Z
suppresses TOP (top of item) and EOI (end of
item) messages. (ED and EDIT only).
The following example uses the Editor to create a new item in the ORDERS file.
The Editor prompts for the item ID:
>ED ORDERS
ITEM ID: 10135
NEW ITEM
TOP
.
The new item ID is 10135. When you invoke the Editor, the system positions the
line pointer at the top of the item. The Editor prompt is a period (.). It is only
possible to enter Editor commands at this prompt.
When you use the full screen editor, I (insert) to enter insert mode and allows you
to type new text. Pressing <ESC> exits insert mode, and typing FI in command
mode saves the new item in the file and quits the Editor. FD deletes the item you
are editing.
Refer to the UniVision Editor Reference Guide for more information on using the
Editor. Refer to the UniDoc Reference Manual for more information on using DE.
Deleting Items
DELETE removes items from dictionary or data files. The syntax is:
DELETE [DICT] filnam item-list
DICT
specifies a file dictionary
filnam
name of the file that contains item-list
item-list
list of item IDs you want to delete. Separate each item ID
with a space. An asterisk (*) specifies all items in the file.
The system deletes the items specified in the item-list from the specified file.
>DELETE ORDERS,PAID '10123'
'10123' Deleted
7-12
Take care when using with DELETE since it has no safety feature. Issuing a
DELETE results in the system removing the item or items from the file
immediately.
However, DELETE does not allow you to delete a file pointer. For example, if you
try to delete a 'D' pointer the system displays the following message:
>DELETE MD INVOICE
[236] File definition item 'INVOICE' not deleted
To remove the Editor from a user's account, you could delete the Verb Definition
item from the Master Dictionary. DELETE does not prompt for confirmation that
you want to delete the item.
>DELETE MD ED EDIT
'ED' Deleted
'EDIT' Deleted
! Note:
If you accidentally delete a verb from the master
Dictionary, you can copy the verb definition from the
NEWAC file located in the SYSPROG account.
If you do not specify the item ID on the command line, DELETE prompts for an
item ID.
>DELETE MD
ITEM ID:ED
'ED' Deleted
In addition, you can delete a list of items if a select-list is present when you
perform a DELETE:
>SELECT INVOICE WITH PAID = "Y"
4 Items Selected
>DELETE INVOICE
'101767 Deleted
'103678' Deleted
'102901' Deleted
'102906' Deleted
File Management
7-13
Creating File Synonyms
As discussed previously, you cannot copy File Definition items from a dictionary.
The system discourages the creation of duplicate D-pointers. Instead, you use Qpointers, or File Synonym items, to reference a file under a different name in the
same account or to access files in other accounts.
The Q-pointer is a symbolic reference to the original file. The system follows this
reference to the File Definition item in the Master Dictionary of the specified
account to determine the location of the file. You can perform most file
management operations on a file regardless of whether you access it by a Dpointer or a Q-pointer. In addition, this is true of all VISION operations. However,
DELETE-FILE is an exception, preventing you from using a Q-pointer to delete
the original file.
While DELETE-FILE deletes the original file and its D-pointer, it does not check
for existing Q-pointers in the Master Dictionary. Make sure you delete any Qpointer if you delete the file they reference.
Creating Q-Pointers
The basic format for a File Synonym Definition item requires you to specify the
first three attributes.
Attribute 1
A 'Q' that identifies the type of item.
Attribute 2
The name of the account where you can find the File
Definition item, as reference in Attribute 3. If null, the
system assumes file is in the same account.
Attribute 3
The name of the file, or more precisely, the item ID of the
File Definition item that identifies the file in the account
specified in Attribute 2. It cannot reference a Q-pointer. If
null, then this item points to the Master Dictionary of the
account.
The remaining attributes are the same as for a File Definition item.
You can create File Synonym Definition items in the Master Dictionary using the
Editor or SET-FILE, as described in the next section. The following example
provides a short synonym for a file:
ORD-1
001 Q
002
003 ORDERS-JANUARY
Attribute 2 is null, indicating that the File Definition item is in this account.
7-14
In the next example, the system can find the file in another account.
BK-CAT
001 Q
002 BOOK-INVENTORY
003 BOOK-CATALOG
This Q-pointer 'BK-CAT' references the file 'BOOK-CATALOG' in the account
'BOOK-INVENTORY'. Because a File Definition item need only be unique in its
own account, another Q-pointer named 'BOOK-CATALOG' could point to the
account as well.
If you access files in another account regularly, it might be useful to create a
pointer to the Master Dictionary for that account. For instance:
MD-STAFF
001 Q
002 STAFF
003
is a Q-pointer to the Master Dictionary of the STAFF account.
! Note:
rd
The 3 attribute is null.
Once you have created this Q-pointer, you could copy items such as Procs
between the two Master Dictionaries. The following example, copies a Proc
named 'ED-PROG' to the Master Dictionary of the STAFF account.
>COPY MD ED-PROG
TO:(MD-STAFF
1 ED-PROG
Now the item 'ED-PROG' exists in both accounts.
A Q-pointer must point to a valid File Definition item or to another Q-pointer.
SET-FILE
SET-FILE creates a temporary Q-pointer. It requires two parameters: the name of
the account containing the file and the name of the file. It creates a File Synonym
Definition item named 'QFILE' in the Master Dictionary containing this
information. Each use of SET-FILE overwrites the previous contents of the item.
This type of file synonym is especially useful in applications for establishing
access to a file in another account in order to run VISION reports or to copy items
from the file. For example, assume you created a catalogued BASIC program
named 'PHONELOG' and you want to make it available to two other accounts. To
do that, you must copy the verb from the current Master Dictionary into the other
accounts. You can use SET-FILE to create a temporary file pointer to the Master
Dictionary of each account.
File Management
7-15
>SET-FILE STAFF MD
'QFILE' Updated
>COPY MD PHONE-LOG
TO: (QFILE
1 PHONE-LOG
1 Items copied
>SET-FILE SALES MD
'QFILE' Updated
>COPY MD PHONE-LOG
TO: (QFILE
1 PHONE-LOG
1 Items copied
Once you have created the QFILE item, it is possible to make a copy of it under a
new name in the Master Dictionary. This is an alternative way to create a
permanent Q-pointer instead of using the Editor.
For instance, if you wanted to create a permanent Q-pointer to the Master
Dictionary of the SALES account, you would enter the following:
>COPY MD QFILE (D)
TO:SALES
1QFILE
1 Items copied
This command makes a copy of the QFILE item under the name 'SALES' and
deletes the original QFILE item from the Master Dictionary.
File Security
On a database management system, most security issues revolve around protecting
valuable data from unauthorised use or modification. This section describes the
various ways that UniVision allows application developers to protect data stored
on the system.
st
The 1 level of file security is preventing unauthorised users from gaining access
to an account. The logon process requires users to specify an account name and,
usually, a password. The use of secure passwords is the best way to limit access
by users and therefore restrict file access. An Account Definition item in the
SYSTEM Dictionary contains the specified account name and password.
7-16
nd
The 2 level of security is restricting user access to UCL. This prevents users
from using the commands that access files. A Logon Proc in the user's account
makes it possible to invoke an application program on successful logon. In
addition, if Attribute 9 of the user's Account Definition item specifies a 'T', the
system denies the user access to UCL whenever an application would normally
return control to the UCL. This is contingent on the existence of a Proc named
'account-name@TCL' in the Master Dictionary or one named '@TCL' in the
ERRMSG file.
rd
The 3 level of security is establishing system privilege levels. UniVision
provides four privilege levels from zero to three with SYS3 being free from
restrictions, SYS0 permits users to access files in an account but not to create or
delete them. In addition, SYS0 users cannot modify the Master Dictionary. SYS1
and SYS2 permit updating of files, but SYS1 users cannot access the system
debugger. SYS3 is the top privilege level, typically used by the administrator and
overrides any other form of protection, such as retrieval and update codes (as
explained below). SYSPROG gives SYS3 privileges automatically; it is
recommended that you give access to the SYSPROG account sparingly.
th
The 4 level of file security is the proper segregation of files in accounts. You
should limit the D-pointer in an account to only those files needed by the users of
the account. You should disable the ability to create Q-pointers in accounts where
it is necessary to restrict access to files outside the account. The removal of the
Editor verbs and SET-FILE from the account ensures that users cannot create Qpointers to access remote files. For instance, an application developer might
determine that files in the PERSONNEL account or PAYROLL account should
not be available to users of the general STAFF account.
th
The 5 level of file security is retrieval and update codes, specified in File
Definition items. These codes can restrict file access among users of the same
account as well as files available to many accounts.
Retrieval and Update Codes
Retrieval and update codes amount to setting up permissions on reading the
contents of a file and modifying the file. You must establish the retrieval and
update codes themselves and use them consistently on each system. The codes can
be any string of ASCII characters. Place retrieval codes in Attribute 5 and update
codes in Attribute 6 of the following items:
•
Account Definition item in the SYSTEM Dictionary.
•
File Definition item in an account’s Master Dictionary or in a File
dictionary.
File Management
7-17
You can specify multiple codes separated by value marks for an Account
Definition item. You can specify retrieval and update codes in the Account
Definition item during CREATE-ACCOUNT. If You do not specify a code, the
system does not perform any retrieval or update checking. In addition, you can
add or modify them, for any item using the Editor. The recommended time for
modifying the retrieval and update codes is when there is no one else logged on to
the system.
Placing a code in a file dictionary pointer protects the data file but not the
dictionary itself. Placing a code in the Master Dictionary, restricts access to both
the dictionary and the data file.
The system determines retrieval and update permissions by comparing the code
specified in the user's Account Definition item with the code in the File Definition
item of the file being accessed. For a match to occur, the code specified in the File
Definition item must be identical to the initial sub-string of any value specified in
the code of the Account Definition item. For instance, a File Definition item with
a code of '12' would match an Account Definition item with a code of '123'.
To access a file in the account, the retrieval code for the file must match any value
in the retrieval code in the user's Account Definition item. To update a file, the
retrieval codes must match, and then the update code of the file must match any
value in the update code for the Account Definition item.
If a file is in a different account, the system compares retrieval and update codes
specified in the remote account's Account Definition item with the codes specified
in the user's Account Definition item. For a match to occur, the first value of the
code for the remote account must match any value specified for the user's account.
The following processors update files and thus require a match for both the
retrieval code and the update code:
•
COPY
•
EDIT
•
RUN
If a match does not succeed, the processor does not continue, and displays the
message that the file is 'access protected'. UniVision BASIC requires a match of
the retrieval and update codes to open a file.
It is possible to establish a fairly simple four-tiered scheme using the string '1234'.
You could classify each user as either '1' (the lowest permission level), '12', '123',
or '1234' (the highest permission level), and classify all files using the same set of
codes. Thus, only users with a retrieval code of ‘123’ or ‘1234 could read a file
containing a retrieval code of '123'. Similarly, a user with any of the four codes
could access a file with a code of '1'. More examples are shown below.
7-18
File Dictionary
Code
User Identification
Code
Result
123
123
Match
12
123
Match
123
12
No Match
XYZ
XUZ5
AQ2
AO
Match
No Match
File Maintenance
UniVision files use a hash-encoding scheme to allow fairly direct access to any
item in a file without searching through the entire file. The success of the hashencoding, and thus the speed of access to any item, depends on a number of
related factors including the type of item in the file, the size of the average item
and of the largest and smallest items, and the structure of the file.
UniVision allows you to improve access speed by adjusting the file modulo. The
modulo determines the number of groups used to store items in. It affects speed of
access in two ways.
The hashing algorithm, that transforms the key, uses the modulo directly in the
hashing algorithm. The modulo should be a prime number to ensure an even
distribution of items.
The modulo determines the typical number of items stored in each group (the
group depth) because it specifies the number of groups. The group depth is a
function of the total number of items divided by the modulo. For example, if the
number of items is 808 and the modulo is 101, the system estimates the group
depth to be 8. The modulo should be sufficiently large such that the expected
number of items in a group fit in the frame allocated for the group.
Designers of UniVision files should try to estimate the total number and size of
items that the file will contain when they are creating the file. However, files have
a tendency to grow beyond their designers' expectations, and therefore you should
check; the size and efficiency of important files and reallocate space for them
when necessary.
Tools for Checking File Efficiency
Two commands that you can use to test and make recommendations about the best
modulo for a file are ISTAT and HASH-TEST. You can check the File Statistics
Report, produced by a full backup or file-save, regularly to look for files that
might need resizing. How often you carry this out depends on how often you
modify the file and how easy it is to access data in the file.
File Management
7-19
Once you find that a file seems to be out of trim, you can use HASH-TEST to
show how the items the system would reallocate if you used a given modulo for
the file. HASH-TEST perform exactly the same function as ISTAT but on a 'what
if' basis. The following describes ISTAT and HASH-TEST in detail below. In
addition, it describes how to resize files with inefficient modulos.
For purposes of illustration, the examples show the results of these commands for
both the default Master Dictionary created in a new user's account, and for the
same data after being copied to another file with a different, much less effective
modulo.
Analysing File Structure with ISTAT
ISTAT produces a summary of the item distribution for a file and analyses the
structure of groups within the file. This item distribution summary can help you
determine whether the current file structure is the best one for the file.
The following example shows the result of ISTAT run on the Master Dictionary of
an account:
>ISTAT MD
FILE= MD MODULO = 7
FRAMES
1
1
1
1
1
1
1
7
BYTES
1006
595
787
898
643
862
1219
15:36:03
21 APR 1988
ITMS
45 *>>>>>>>>>>>>>>>>>>>>>>>>>>>
28*>>>>>>>>>>>>>>>>>>>>
38 *>>>>>>>>>>>>>>>>>>>>>>>
42 *>>>>>>>>>>>>>>>>>>>>>>>>>
33 *>>>>>>>>>>>>>>>>>>>>
45 *>>>>>>>>>>>>>>>>>>>>>>>>>>>
49 *>>>>>>>>>>>>>>>>>>>>>>>>>>>>
ITEM COUNT= 280,
BYTE COUNT= 6010 AVG.BYTES/ITEM= 21.4
AVG.ITEMS/GROUP=40.00 STD.DEVIATION= 7.4, AVG.BYTES/GROUP= 858.5
You can see that the distribution of the items is even, with an average of 40 items
in each group.
Testing File Structure with HASH-TEST
HASH-TEST produces the same listing as ISTAT shown above, but displays what
the distribution of records would be if you chose a given modulo.
The following example shows the result of HASH-TEST run on the same Master
dictionary as in the preceding section with ISTAT. It uses a test modulo of 3
instead of the actual modulo of 7:
7-20
>HASH-TEST MD
TEST MODULO:3
FILE= MD MODULO= 3
FRAMES
1
2
2
BYTES
1740
2005
2265
15:44:46 21 APR 1988
ITMS
78 *>>>>>>>>>>>>>>>>>>>>>>>>>>>>!
98 *>>>>>>>>>>>>>>>>>>>>>>>>>>>>!
104 *>>>>>>>>>>>>>>>>>>>>>>>>>>>>!
Item Count= 280, Byte Count= 5010, Avg Bytes/item= 21.4
Avg.items/Group =93.3, Std Deviation=13.6, Avg.Bytes/Group=2003.3
You can see that there is an even distribution across 3 groups, with an average of
93 items in each group. The most obvious problem is that the number of
characters in each group is too large and exceeds one frame.
On the other hand, with a test modulo of 79, this is the result:
>HASH-TEST MD
TEST MODULO:79
FILE= MD MODULO= 79
FRAMES
1
1
1
1
1
1
1
.
.
.
1
1
1
1
79
15:44:46 21 APR 1988
BYTES
119
178
34
119
24
0
79
ITMS
5
9
2
6
1
0
6
62
117
105
36
2
5
6
2
*>>>>>
*>>>>>>>>>
*>>
*>>>>>>
*>
*
*>>>>>>
*>>
*>>>>>
*>>>>>>
*>>
Item Count= 280, Byte Count= 6010, Avg.Bytes/Item= 21.4
Avg.Items/Group= 3.5, Std.Deviation= 2.0, Avg Bytes/Group = 76.0
Here things are just as bad, but in the opposite direction: several of the frames are
empty, and the system is only using only four per cent of the space allocated to
each group, a very inefficient use of disk space.
File Management
7-21
It is possible to make a few general observations about the number of items per
group and the size of groups. If items have sequential numeric IDs, the system
distributes the items evenly. If keys are random (that is, not in any particular
sequence), the distribution varies. A small modulo and a large number of bytes per
group might raise the average access time of items if you need to scan more than
one data frame. A large modulo and a small number of bytes per group wastes
disk space but provides faster access. The trick is to find the right modulo to
balance the number of items per group. One frame per group is ideal.
The minimum number of frames per group is one, even for any empty group. A
thousand empty groups is worse than having three hundred groups where only
some of them require an overflow frame. While the larger file provides more
direct access, this affects the VISION and the file-save processor since they have
to read empty frames into memory.
In addition, remember that the system places an updated item at the end of the
group. Having a modulo too small requires extra time to find where the item
starts, move the other items nearer the front of the group, and place the updated
item at the end. Many groups containing many items affect performance.
A low standard deviation (about 1 or less) is good because it is a sign of even
distribution. If an item size is greater than one frame, (for example is program
source), you cannot help using additional frames. The best choice here is one item
per group, but you must balance it against how many empty groups might exist if
the modulo was very large.
Examining Groups in Closer Detail
GROUP and ITEM are two commands that allow you to look at the distribution of
items in groups in closer detail. GROUP shows some information about each item
and summarises the contents of each group. For each group, it lists the number of
items, the total number of bytes, the number of full frames, and the number of
bytes used in the last frame. ITEM produces the same information for a single
group to which a particular item hashes.
The syntax is:
GROUP [DICT] filnam [(P)][(S)]
DICT
specifies the file dictionary.
filnam
name of the file.
P
sends report to the printer.
S
suppresses the item-list.
GROUP lists items by group, within each group, it lists each item separately
(unless you use the S option). The following example shows the first page of
group statistics for the file ORDERS:
7-22
>GROUP ORDERS
The report displays statistics in the following format:
frame IDs
(hexadecimal) number of characters
frame ID
(hexadecimal) displacement from frame ID
item ID
8115
0047
8115.030 HJENK1222M
003F
8115.077 SPIRS112A
0048
8115.0B6 AJOHN760JE
3 ITEMS 206 BYTES 0/206 FRAMES
8116
004C
8116.030 BLEAR34TRE
0042
8116.07C JBOHA126TR
004D
8116.0BE JBUCK26STO
003D
8116.0FE JPEER89RIA
003D
8116.13B HJOHN455OT
8117
0042
8117.030 MASH912AE
003C
8117.072 DEDGE338BR
004F
8117.0AE AORLA55VEN
3 ITEMS 205 BYTES 0/2O5 FRAMES
At the end of each group listing, the system displays totals that provide the
number of items in the group; the total number of bytes used in the group; the
number of full frames in the group; and the number of bytes used in the last frame
of that group, in decimal. S only displays this line for each group.
ITEM accepts an additional parameter, an item ID. The report produced by this
command displays the same information as GROUP except that it shows only one
group, the one to which the specified item hashes. The item need not exist, so you
can use ITEM to find out to which group a particular item hashes.
>ITEM ORDERS
ITEM ID:10104
10104
9529
0029 9529.030 10107
0022 9529.059 10119
0039 9529.07B 10110
0023 9529.0B4 10122
002A 9529.0D7 10113
0036 9529.101 10104
0033 9529.137 10116
0022 9529.16A 10101
0022 9529.18C 10134
File Management
7-23
This report shows that item '10104' hashes to a group whose frame ID is 9529. It
th
is the 6 of nine items in the group. The items in this group are quite small,
totalling 382 bytes. In the next example, the group examined is from a file
containing UniVision BASIC programs.
>ITEM BP PHONE-SEL
PHONE-SEL
9478
0894 9478.030 ODATA-ENTRY
00A2 9481.0F4 PHONE-SEL
>XTD 894
2196
>XTD 00A2
162
There are two items in this group, occupying two frames. It invokes XTD to
convert the size of each item in bytes from hexadecimal to decimal. Thus, the first
item is 2196, 2000 of which can fit in the first frame of the group. This
information is helpful in evaluating the size of this file, showing you that items
exist that are larger than a single frame.
Reallocating Files
Once you have determined that a file needs a new modulo, it is easy to reallocate
the space for it. You do this by specifying a reallocation parameter as Attribute 13
of the file Definition item. You must enclose the new modulo in parentheses. The
reallocation takes place by performing an account-save or file-save followed by an
account-restore or file-restore.
The following procedure summarises how to back up and restore the account
containing the file:
•
•
Change the modulo by entering the new modulo, enclosed in parentheses,
in Attribute 13 of the File Definition item or Account Definition item.
Back up either the account containing the file or the entire data area (with
ACCOUNT-SAVE or FILE-SAVE). Refer to the UniVision System
Administration Guide for information about backing up and restoring
files.
•
Restore either the account or the entire data area (with ACCOUNTRESTORE or :FILELOAD). The system creates a file with the new
modulo and restores the items to it.
7-24
R is available for ACCOUNT-RESTORE or :FILELOAD to alter the effects of
bypassing any resize parameters. R allows you to recover from problems
encountered with incorrect resize parameters. For example, if you resize a file or
set of files more than the current amount of disk space you have available. R is
available to restore the data without applying any resize setting in attribute 13.
In addition, you can copy data from the file you want to resize to a newly created
file with the correct modulo. The method using COPY is less common and might
be inappropriate for very large files.
•
Create a temporary file using CREATE-FILE.
•
Copy the contents of the file you want to resize into the temporary file
using COPY.
•
Delete the original file using DELETE-FILE.
•
Create a new file with the new modulo.
•
Copy the contents of the temporary file into the new file.
•
Delete the temporary file.
You can resize larger files by writing the file to tape with T-DUMP and restoring it
to disk with T-LOAD. In COPY operations, make sure that you do not forget the
dictionary items.
Of all of these methods of file allocation, the most common one is a file-save and
restore using :FILELOAD. The system administrator should perform this when
there is no one else logged onto the system. :FILELOAD deletes all SYSTEM
entries immediately, and requires a tape to be ready. Since this is a planned save
and restore, you should use the validation check of FILE-SAVE to ensure the tape
is good before any optional or elective restore.
A full file-restore is the only way to ensure the reallocation of files in one block of
contiguous frames. That is, all secondary file frames for each group follow the
primary file area (one frame per group). Reallocating files using COPY or
ACCOUNT-RESTORE creates a contiguous block for primary space, but the
secondary space comes from the Overflow Table. A full file-restore can improve
performances.
When selecting the reallocation parameter, here are a few things to remember:
•
The modulo should be a prime number.
•
The modulo should not be divisible by three or five.
These are not 'hard and fast' rules, but help to ensure a more even distribution of
items in groups.
File Management
7-25
Backup and Restoration
Making backups of files on tape is an important part of protecting data and
ensuring the integrity of files. If you accidentally delete a file subsequently or if
its data becomes corrupted, you can restore the most recent version of the file
from tape.
Generally speaking, the system administrator at each site should establish routine
backup procedures for the entire system. Nonetheless, application programmers
should know enough about these procedures to understand the contents of the
back up and how often it occurs.
There are two types of backup: full and partial. A full backup saves the entire data
area of disk; a partial backup saves only a portion of it. It is possible to make
partial backups that save an entire account.
For a complete description of the backup and restoration strategies and
procedures, refer to the UniVision System Administration Guide. This section
describes the account-save and account-restore procedures. An account-save is
similar to a file-save; it backs up a single account whereas a file-save backs up all
accounts on the system. In addition, you can use the account-save and restoration
process to move an account from one UniVision to another via tape.
The commands that allow you to back up and restore a single account are:
ACCOUNT-SAVE
A full backup of all files in a single account.
ACCOUNT-RESTORE
Restores ACCOUNT-RESTORE an entire account from an
ACCOUNT-SAVE tape.
In addition, the following command is useful for restoring individual items from a
tape.
SEL-RESTORE
Restores one or more items selectively from a file on a tape
created by the FILE-SAVE or ACCOUNT-SAVE tapes.
These commands are available in the SYSPROG account and for details of their
syntax and use, refer to the UniVision Command Reference Guide.
7-26
Section 8
ACCOUNT MANAGEMENT
This section examines account management in the context of individual users and
groups of users. It describes the facilities for managing accounts available in the
SYSPROG account. It looks at the structure of items that identify the account and
users of the account at the system level. It looks at how to tailor an account's
Master Dictionary. It touches on accounting history, system messages, and
security on an account level.
Account management is mostly the responsibility of the system administrator. It
involves issues affecting all users of the system and requires access to the
SYSPROG account. However, application programmers should understand the
issues involved in maintaining and managing multiple user accounts, and the
activity of users working in those accounts.
The SYSPROG Account
It is only possible to perform many of the system-level tasks in a special account
called the SYSPROG (SYStem PROGrammer) account. The SYSPROG account
gives unlimited access to all files on the system as well as to certain commands
that ordinary users cannot invoke because their Master Dictionary does not
include those commands.
The SYSPROG account is the account used to maintain the entire UniVision
system. You can only perform starting up and shutting down the system, backing
up and restoring the system, and many other administrative tasks, from the
SYSPROG account. The SYSPROG Master Dictionary contains a number of
verbs used for administrative purposes not found in any other account on the
system.
Accessing the SYSPROG Account
You should password protect the SYSPROG account. The password prevents
unauthorised users from accessing the verbs and files in this account. If the
administrator has given you authorisation to use the SYSPROG account, you can
log on to it from the logon prompt. In addition, you can log to it from another
account using LOGTO.
The rest of this section describes files and verbs accessed from the SYSPROG
account.
Account Management
8-1
Contents of the SYSPROG Account
The SYSPROG account contains files used for administrative purposes. They are
similar in function to the system-level files contained in the SYSTEM Dictionary,
described in a later section. You can find more detailed information about these
files in the UniVision System Administration Guide.
SYSPROG Commands
The commands in the SYSPROG account are available for the system
administrator to set up and maintain the system. This section describes the
administrative commands, both verbs and Procs, available only in the SYSPROG
account, arranged in functional groups; you can find details of these commands in
the UniVision Command Reference Guide. For more information on a number of
system administration tasks that use these commands, refer to the UniVision
System Administration Guide.
Start-up and Shutdown
STARTUP
Performs verification tasks required for a given installation
each time you start up the system.
RESET-PROCESS
Resets a process record corrupted by an untidy exit from
UniVision.
Setting the Date and Time
IDATE
Sets the system date format to the international standard.
UDATE
Sets the system date format to the United States standard.
SET-DATE-EUR
Sets the system date format to the international standard.
SET-DATE-STD
Sets the system date format to the United States standard.
! Note:
8-2
The administrator should use the date commands in
UNIX to make adjustments to system time and data. The
user must be a UNIX super-user to change the system
time and date. A UNIX super-user logs in as root.
Account Management
CREATE-ACCOUNT
Creates accounts, defines retrieval and update lock codes for
them, and defines system privilege levels.
DELETE-ACCOUNT
Deletes an account and all its files from the system
AUTO-LOGOFF
Logs off specified processes automatically after a designated
period of inactivity or the loss of an incoming DTR signal.
LOCKOUT
Prevents prospective users from logging on if a specified
number of invalid attempt to logon have occurred.
LOCKOUT-STATUS
Displays the parameters currently in effect for LOCKOUT.
LIST-SECURITY-LOG
Lists all security violations logged in the SECURITY-LOG
file.
System Maintenance and Control
TANDEM
Allows display and control of another process on your
terminal; TANDEM effectively links two lines to one process.
POKE
Inserts a UCL command or a character string in the input
buffer of another process.
MAXUSERS
Sets the maximum number of user who can log on to the
system at any one time.
:AUTHORIZE
Displays the current User Serial Number and Current
Authorisation Code and allows the system administrators to
changes the Authorisation Code.
MODEM-ON/MODEM-OFF
MODEM-ON enables DTR monitoring for a specified line.
MODEM-OFF disables DTR monitoring.
:STARTSPOOLER
Initialises or restarts the Spooler without restarting the whole
system.
SET-TERM
Sets the system wide default characteristics for terminals and
printers.
SET-TAPE
Assigns a logical tape unit to a physical tape device.
Account Management
8-3
:INIT-TAPE
Resets all logical tape units to their default assignments, and
clears all tape buffers.
:INIT-DISK
Allows a user to allocate UNIX disk space reserved for the
UniVision environment.
:INIT-SYSTEM
Sets the type of hardware platform in use. This setting allows
UniVision to make correct decisions regarding the
configuration of the hardware.
BUILD-LOCK-XREF
Builds the LOCK-XREF file, containing the UniVision file
pathnames for all accounts and files in the UniVision
environment.
DEFINE-CURSOR
Allows administrators to change the UNIX terminal type to
UniVision term type letter cross-reference.
BUILD-TR-INDEX
Builds and index of all triggers, indexing and replicas on the
system
LIST-TR-INDEX
Lists the index of triggers, indexing and replicas.
CLEAR-GROUP-LOCKS
Clears all the group locks in the system group lock table.
RESET-ITEM-LOCKS
Clears all the item locks in the item locks table set by the
UniVision BASIC statements READU, READVU and
MATREADU.
! Note:
Use CLEAR-GROUP-LOCKS and RESET-ITEM-LOCKS
with caution; they override the protection provided by
the UniVision environment to prevent data corruption
and Group Format Errors, GFEs.
System Monitoring
DUMP
Displays the contents of disk frames including information
about forward and backward links.
LIST-FILE-STATS
Lists the statistical information from the most recent FILESAVE operation.
8-4
System Backup
FILE-SAVE
Saves the entire data area of the disk to tape.
ACCOUNT-SAVE
Copies a specified account to tape.
SAVE
Copies all or part of the data area of the disk to tape. All
PROCs used to make backup tape invoke SAVE.
System Restoration
:FILELOAD
Restores all data on the disk using any full file-save tape,
that is, those made with the FILE-SAVE commands.
ACCOUNT-RESTORE
Restores a single account from a FILE-SAVE or ACCOUNTSAVE tape.
ADD-ACCOUNTS
Restores all accounts that are present on a FILE-SAVE, or
ACCOUNT-SAVE tape, but are not on disk.
Server Control
:STOP-MASTER-SERVER
Stops the master server.
SERVER-STATUS
Displays the contents of specified Server Status files.
Miscellaneous Administrative Commands
COMPARE
Compares items and highlights differences and insertions.
>>
Enters a multi-command level without entering Debugger.
<<
Exits from multi-command level without entering Debugger.
Copying SYSPROG Commands
The reason why commands are in the SYSPROG account and are not available to
all users is that use of these commands could affect other users on the system.
Recommended practice is that only knowledgeable users should attempt to use
them. If you give authorisation to access these commands, the user should
understand them thoroughly and exercise caution when using them.
Account Management
8-5
It is possible to access some SYSPROG commands, but not all of them, from
accounts other than SYSPROG. If you access individual verbs in the SYSPROG
account regularly, it might be worth considering duplicating the verb in the Master
dictionary. However you should implement some way of restricting others from
this account.
You should not copy the verb from the SYSPROG Master Dictionary. Instead,
copy it from SYSMD file. This file contains verbs that you can use outside the
SYSPROG account. The commands that you cannot access outside SYSPROG
usually reference files defined in the SYSPROG Master Dictionary or the
SYSTEM Dictionary.
User Account Management
You use the SYSPROG account to set up and maintain user accounts. This section
describes the creation and deletion of accounts and the maintenance of a system
accounting history.
Creating and Deleting Accounts
CREATE-ACCOUNT creates a new user account. DELETE-ACCOUNT removes an
account from the system and deletes all the files defined in that account. You
should you both of these commands from the SYSPROG account.
CREATE-ACCOUNT prompts for the name of the new account, retrieval and
update codes for the account, the privilege level of the account, the modulo for the
Master Dictionary, and any password used to access the account. It creates a new
Account Definition item in the SYSTEM Dictionary. It is possible to change
many of these specifications later by editing the Account Definition item. For
instance, you can add or modify update and retrieval codes at a later time. In
addition, you change the account's password using PASSWORD.
CREATE-ACCOUNT creates the Master Dictionary for the account by copying the
NEWAC file in the SYSPROG account. Although there is a standard NEWAC
file shipped with each system, administrators can modify this file for a particular
site. For instance, you can create new items in NEWAC to include Procs, Qpointers to global files, and catalogued UniVision BASIC programs. In addition, it
is possible to remove certain items from NEWAC-verbs that invoke the Editor, for
instance. In this way administrators can establish the standard contents of a new
account.
DELETE-ACCOUNT is obviously a very destructive command. It not only deletes
the Account Definition item from the SYSTEM Dictionary, it deletes the
account's Master Dictionary and all the files defined in that account. You should
only run this program when there are no other users logged on the system.
For more information on creating and deleting accounts, refer to the UniVision
8-6
Account Usage Statistics
The UniVision system keeps track of system usage for each user in the
Accounting History file (ACC). Users must have a 'U' specified in Attribute 9 of
the Account Definition item to store accounting information. The ACC file keeps
track of information about users currently active on the system, such as the logon
date and time. In addition, it accumulates usage statistics for all users. You can
use the ACC file to keep accumulates usage statistics for all users and to keep
track of system usage for security or billing purposes.
The UniVision System Administration Guide describes the ACC file in detail.
CHARGES and CHARGE-TO Verbs
CHARGE-TO and CHARGES make use of the Accounting History file for keeping
track of computer usage during a work session. CHARGES reports the charges
incurred for the current work session in the account. CHARGE-TO allows a user to
change the charge-account that they want to bill for subsequent use of the system.
CHARGES displays the same one-line report as displayed when you log off the
system. It states how long the user has been logged on the system and the amount
of CPU time used (in tenths of a second). This information is useful for obtaining
the current status of the work session without, of course, ending it. The following
example shows the use of CHARGES:
>CHARGES
[]Connect time = 110 minutes; CPU = 48 units Printer = 0 pages[]
>
The connect time reported is the amount of elapsed time since the user logged on.
The CPU time reflects actual processing done by the user including activation
overhead. CHARGES does not write this information to the Accounting History
file, the system carries this out when the user actually logs out.
You can use CHARGE-TO to keep separate records for different activities
performed during a single session. For instance, the system might charge a user to
one department while performing certain activities and to another department
while performing other activities. Using CHARGE-TO ends the current work
session, displaying the usage statistics shown above, and begins a new work
session. Using CHARGE-TO does not end the current logon session.
When invoking this verb, you should specify a single argument, that is any ASCII
string. It identifies the charge-account you want to bill. The system appends the
name of the charge-account to the name of the account, and separates it with an
asterisk.
Account Management
8-7
Entering CHARGE-TO without any parameter removes the charge-account
identifier.
The SYSTEM Dictionary
The SYSTEM Dictionary controls the entire system. It holds several different
types of files and items:
•
•
Users IDs
•
Special operator accounts.
•
Message items
•
System level files.
The following sections give brief definitions of each of these types.
These are items that define all accounts on the system, together with their
associated passwords, security codes, and system privileges. They function as
pointers to each account's Master Dictionary. Refer to the Section entitled
Database Architecture for the format of Account Definition Items.
User IDs
A user ID is an Account Synonym Definition item pointing to the account a user
actually logs on to. User IDs can have passwords, security codes, and system
privileges that are different from those of the Account Definition item. Refer to
the Section entitled Creating and Deleting Accounts in the UniVision System
Administration Guide for more information.
Special Operator Accounts
These are special accounts that operators can log on to in order to perform specific
backup functions or cold-start the system. These accounts are:
•
STARTUP
•
FILE-SAVE
The items that define these operator accounts are Account Synonym Definition
items (Q-pointers) pointing to the SYSPROG account and invoking a Logon Proc.
The UniVision System Administration Guide describes operator accounts.
8-8
Message Items
The SYSTEM Dictionary contains the system logon message. The item called
LOGON contains the logon message and the system displays it on the screen
when there is no user logged on to any UniVision account. The standard logon
message is as follows:
[]
UniVision time is
09:39:27
23 AUG 1995
[]
Logon Please:
The above logon message has the same format and structure as any ERRMSG
item. You can change the contents of the logon message using the system editor
(ED[IT]) or full screen editor (D[OC ]E[DIT]). You can display the standard logon
message using CT.
>CT SYSTEM LOGON
LOGON
001 L
002 H[] UniVision time is
003 T
004 H
005 D
006 H[]
007 L
008 L
009 HLogon Please: +
You can modify the UniVision message following the rules outlined in 'Format of
ERRMSG' later in this Section
! Note:
You should not update any item in the SYSTEM file
while there are users logged on to UniVision.
There are two conditions where UniVision can change the above logon message
st
automatically. The 1 different logon message occurs when the number of users
exceeds the maximum set. The other way is when a process exceeds its lockout
settings that limit the number of failed logon attempts.
MAXUSERS can change the setting for the maximum number of users who can
log on to the system at any one time. MAXUSERS is useful when you want to
restrict access to UniVision. For example, you should have all users log off during
a file-save. Setting the maximum number of users to zero can prevent users from
logging on until the system administrator allows logons after completion of the
file-save. If the number of users ever exceeds the maximum, the system displays
the following message:
Account Management
8-9
LOGON DENIED: Maximum licensed number of users reached
[]
UniVision time is
10:03:23
23 AUG 1995
[]
Logon Please:
st
It is not possible to change the 1 line of the message. However, any modifications
to LOGON as described above alter the last two lines of the message.
The LOCKOUT item in the ERRMSG file contains the 'LOCKOUT in process'
message. The system displays this message after a user's process reaches the limit
of permissible invalid logon attempts. Refer to LOCKOUT and LOCKOUTSTATUS in the UniVision Command Reference Guide for further details. The
default logon message during a lockout condition is as follows:
+--------------------------------------------------------+
+
+
+
LOCKOUT in progress for nnn minutes
+
+
+
+--------------------------------------------------------+
Try Later:
! Note:
A lockout remains in effect for the number of minutes
specified by 'nnn'. LOCKOUT sets the number of minutes
before allowing additional logon attempts. The message
displayed shows the amount of time before the system
allows a logon attempt. The system administrator can
override this setting.
You can change the above default message using one of the system editors and
following the rules outlined in Format of ERRMSG Items later in this section.
System Level Files
The SYSTEM Dictionary contains pointers to special system files essential to the
operation and maintenance of the UniVision environment. Below is a description
of these files.
ACC
8-10
The ACC file, or Account History file, contains two types of
st
item. The 1 type holds data about users actively logged on
nd
to the system. The 2 type holds data that keeps track of
usage statistics for users; when they logged on, how much
computer time they used, how many pages they sent to the
printer, etc. The system updates these items when users log
off. Refer to the Section entitled System Security, for more
information about the Account History file.
BLOCK-CONVERT
The BLOCK-CONVERT file contains the format of the
characters displayed when using BLOCK-PRINT. Each
Master Dictionary on the system contains a Q-pointer to
BLOCK-CONVERT.
DEVICE, DETAILS (DEVICE-DETAILS)
The DEVICE-DETAILS file contains information on the
tape devices installed under UNIX. :INIT-SYSTEM and :INITTAPE create the items in this file. Various tape commands
use the information contained in this file to perform tape
operations.
DEVICE, ERRORS (DEVICE-ERRORS)
The DEVICE ERRORS file contains information on the
tape error messages used under UNIX. :INIT-SYSTEM and
:INIT-TAPE create the items in this file. Various tape
commands use the information contained in this file to
recover from UNIX tape errors.
DEVICE, NAME (DEVICE-NAMES)
The DEVICE-NAMES file contains information on the
optional tape name created in the UniVision environment.
:INIT-SYSTEM and :INIT-TAPE create the items in this file.
Various tape commands use the information contained in this
file to use the correct tape device.
ERRMSG
The ERRMSG file contains system messages. Some of these
messages just provide useful information, others provide
warnings or indicate error conditions. Each Master
Dictionary on the system contains a Q-pointer to ERRMSG.
There is a description of the format of the ERRMSG file in
the section entitled The ERRMSG File. The UniVision
Command Reference Guide, Volume 2, contains a list of the
system messages.
LOCKS, GROUPS-LOCKS (GROUP-LOCKS)
The GROUP-LOCKS file contains a list of group locks set
by the UniVision environment. Group locks ensure database
integrity.
LOCKS, ITEM-LOCKS (ITEM-LOCKS)
The ITEM-LOCKS file contains a list of item locks set in
the UniVision BASIC programming language. The
application code uses item locks to ensure database integrity.
Account Management
8-11
LOCKS-XREF
The LOCKS-XREF file contains file path names for all
account and files in the UniVision database. The system uses
the data contained in this file to display the account and file
names rather than the frame of page number.
NEWAC
The NEWAC file is a template for the Master Dictionaries
of all accounts on the system: when the administrator creates
a new account’s Master Dictionary, the system copies the
contents of the NEWAC file to it. The system uses the
SYSMD file is the SYSPROG account as a template for
accounts requiring SYSPROG capabilities.
POINTER-FILE
The POINTER-FILE contains saved select-list items.
SECURITY-LOG
The SECURITY-LOG contains items that record invalid
logon attempts, system privilege violations, file access
protection violations, etc.
STAT-FILE
The STAT-FILE stores the file statistics information. FILESAVE or SAVE with the S option creates items in the STATFILE. The administrator uses this information to generate
the file statistics report available at the end of a file save of
regenerated by using LIST-FILE-STAT.
STORE-PATHS
The STORE-PATHS file contains information on the disk
devices installed under UNIX. :INIT-DISK creates the items
in this file. The administrator uses the information contained
in this file when they want to add additional disk space to the
available space pool.
8-12
UVPROCS
The UVPROCS file contains all common Procs such as
LISTU, LISTFILES, CT, etc. Each Master Dictionary
contains a Q-pointer to UVPROCS, as well as items the link
to the Procs stored in UVPROCS.
UVPROGS
The UVPROGS file contains all common UniVision BASIC
programs. Each Master Dictionary contains a Q-pointer to
UVPROGS.
UV.HELP
The UV.HELP file contains all the documentation available
to the On-line help utility.
The ERRMSG File
The ERRMSG file provides a standard set of system messages for use by
UniVision system processors as well as application programs. An item in this file
contains a series of instructions interpreted by the ERRMSG processor. The next
section describes the format of ERRMSG items.
The following screen shows a simple example of an item in the ERRMSG file in
st
nd
two different formats. The 1 format is a listing produced by CT. The 2 format is
a listing produced by PRINT-ERR.
>CT ERRMSG 414
414
001 L
002 E Invalid specification of a file
>PRINT-ERR ERRMSG 414
[414] Invalid specification of file
>
You can use PRINT-ERR to invoke the ERRMSG processor on an item in any file.
Many of these messages alert the user to an error condition, but might inform the
user about the progress or the completion of an operation. A good example is item
[289] in the ERRMSG file. TERM uses it to present a formatted display of
terminal and printer settings.
You can use STOP and ABORT in UniVision BASIC to invoke the error message
processor and pass parameters to it.
Format of ERRMSG Items
An item in the ERRMSG file contains instructions that direct the actions of the
ERRMSG interpreter. ERRMSG items work similarly to Procs: the system builds
a message in an output buffer and displays the contents of the output buffer on the
screen. You can form the message from the list of parameters passed to the
ERRMSG processor, from literal strings, or from system variables for date and
time.
By convention, many items in the ERRMSG file use numeric item IDs. Those
starting with 'B' are for UniVision BASIC. When creating new items in this file,
you should be careful not to overwrite existing items used by the system. You
might want to use a standard prefix as part of the item IDs so that you can identify
st
the messages specific to an application. The 1 character on each line describes a
specific action.
Account Management
8-13
A
Inserts the next parameter in the list of parameters passed to
the ERRMSG processor.
A(n)
Inserts next parameter in a left-justified field of width n.
D
Puts the date in the output buffer.
E
Output ID of the error message. Use it in place of H or on a
line by itself. Typically found in Attribute 1.
H
Places the string that follows in the output buffer.
H+
Suppresses final carriage return or line feed when specified
on the last line of the item.
L(n)
Inserts a carriage return or line feed into output buffer. If you
specify (n), the system follows the message with n carriage
returns.
R(n)
Inserts the next parameter in a right-justified field of width n.
S(n)
Sets the pointer in the output buffer to position n.
T
Puts the current time in the output buffer.
X
Skips a parameter in the parameter list.
The following example shows several lines of a UniVision BASIC program.
OPEN specifies a STOP condition executed when the system cannot find the file.
The STOP specifies two parameters: the item ID of an item in the ERRMSG file
and the string you want to pass. In the following example, the string is the name of
a file.
FILE="CUSTOMER"
OPEN"",FILE ELSE STOP 201, FILE
It invokes the ERRMSG processor on item 201, a standard error message.
The following shows this item:
201
001 E'
002 A
003 H' is not a UniVision file name
Lines 1 and 3 output literal text. Line 2 retrieves the name of the file; specified as
the parameter following the message number. When the program invoked this
error message, you would see:
[201]'CUSTOMER' is not a UniVision file name
8-14
When you pass multiple parameters from UniVision BASIC to ERRMSG
processor, you separate parameters with attribute marks.
STOP "MYMSG"; "PARAMA"; CHAR(254); "PARAMB"
Logon Messages
Several messages seen by the user are items in the ERRMSG or SYSTEM
Dictionary. You specify them in the format of ERRMSG items. You can find the
Logon Please message in SYSTEM.ERRMSG items [335] and [336] contain the
connect time messages displayed when a user logs on or off the system. In
addition, [335] gives the date and release number of the operating system.
@TCL
You can create an @TCL Proc in the ERRMSG file to assume control over a
user's process when control would otherwise pass to the UCL processor. In order
for the @TCL Proc to receive control, the user's Account Definition item must
specify a 'T' in Attribute 9. If the user's Master Dictionary contains an Proc named
'account-name@TCL', the system executes that Proc instead of @TCL in
ERRMSG.
Account Management
8-15
Section 9
THE SPOOLER
The Spooler is a process that manages access to printers by multiple users. For
most users, the function of the Spooler is transparent to them. They generate a job
for a printer and go to the printer to pick up their output. These users are probably
not aware of a Spooler intervening to capture their output and direct it to an
available printer. The Spooler permits users to continue working without waiting
for a print job to finish printing.
This section introduces how the Spooler works and the commands used to modify
its operation. The main focus is on the Spooler-related tasks that you can perform
from user accounts, such as changing the default printer assignment, cancelling a
job, and capturing output in Spooler hold files. The system administrator handles
most of the tasks involving Spooler administration, such as installing and starting
up new printers. Refer to the UniVision System Administration Guide for more
information.
Basic Operation of the Spooler
The UniVision Spooler manages any UniVision job that is 'sent to the printer'. The
following VISION command uses the keyword 'LPTR' to direct the output to the
printer.
>LIST CUSTOMERS LAST-NAME FIRST-NAME LPTR
In addition, most commands accept the parenthetical option P to send the output
of a command to the printer.
The Spooler is a special process used by the UniVision environment to control all
printers connected to the system and activated in UniVision. The Spooler runs as a
separate deamon process, that is a process not linked or attached to any line. The
UniVision Spooler is always running in the background waiting for opportunities
to direct completed print jobs to the appropriate printer. The UniVision Spooler
sends print jobs by issuing the appropriate lp command to the operating system
spooler.
The Spooler
9-1
In UniVision, the system assigns a number to each printer connected to it, starting
with printer number 0, usually the default system printer. In addition, you can
assign each printer from one-to-three different form queues, allowing you to use
different paper sizes and formats with the same printer. You can assign the same
form queue to several different printers, so that if a printer is printing a job
nd
currently, it is possible to print a 2 job sent to the same form queue on another
printer if it is available.
In short, the UniVision Spooler has the following roles:
•
It spools print jobs by directing the output from a user's process to a
UniVision print file. In addition, it creates an entry in the print queue for
the job. This entry queue allows UniVision to manage the print job until
submitted to operating system spooler in UNIX or AIX.
•
It spools print jobs to the operating system spooler by issuing the
appropriate lp command. The system issues the lp command for the
appropriate and available printer. This allows UniVision users and users
on other UNIX or AIX based products to share the same printer devices.
•
UniVision maintains copies of the print files and they follow the normal
rules for UniVision print jobs described later in this section.
For further information on setting up printers, refer to the UniVision System
Administrator Guide.
About Printers and Forms
You reference each printer connected to the system by number. Usually printer
number 0 is the default system printer. The administrator assigns each printer a
number when they add it to the system. In addition, the administrator can assign
up to three form queues to a printer. The default is form queue 0.
You can consider a form queue as a logical printer. A form queue represents any
printer or printers set up to handle the same computer paper or preprinted form.
You can assign multiple printers to service the same form queue. Figure 9-1
illustrates how you might assign several printers to service different form queues.
The following illustration, directs form queue 1 to two line printers using 130column computer paper. A job sent to form queue 1 prints on either Printer 1 or
Printer 2. When you load Printer 3 with preprinted labels, it services form queue
2; when loaded to print envelopes, you must configure Printer 3 to service form
queue 3.
9-2
Form Queue 1
Printer 1
Printer 2
Form Queue 2
Printer 3 with labels
Form Queue 3
Printer 3 with envelopes
Figure 9-1.
You assign printer to serve a form queue
At startup, the administrator decides the form queue serviced by Printer 3. To
change the form queue, the administrator must remove the printer from the system
and restart it.
! Note:
You can direct jobs to form queue 2 or 3, regardless of
the form queue assigned to Printer 3.
If Printer 3 is servicing form queue 2, the system accepts jobs sent to form queue
3 and holds them in the print queue. When you restart Printer 3 to service form
queue 3, the system outputs the spooled jobs.
Each account has a single form queue assigned to it, as illustrated in Figure 9-2.
The default is from queue 0, usually directed to the default system printer. Users
can change the form queue assignment for their account, using SP-ASSIGN.
! Note:
The Spooler
It is important to remember that users do not choose a
system printer directly; they choose a form queue
serviced by that printer.
9-3
Assigned Form Queue
Account
Figure 9-2
You assign a single form queue to an account
Consider as an example a system with only one printer. The administrator sets up
this printer as the default printer 0 that services form queue 0. The default form
queue assignment handles all jobs on 130-column computer paper. However, it is
possible to set up the same printer to handle special preprinted invoices. You
direct these special jobs to form queue 1 by changing the form queue assignment
in the account.
When you submit the print job, the Spooler looks to see if any printer is servicing
that form queue. If the printer is not printing another job currently the system
handles a job sent to form queue 0 immediately. The system holds a job sent to
form queue 1 until you restart the printer to service that form queue. Perhaps you
decide to holds invoices and print them at the end of the day.
The Spooler allows users to share a single printer or multiple printers, as well as to
use a single printer to print on different types of paper or forms.
Print Files and Hold Files
Each print job generates a print file. The job's entry in the print queue points to the
location of the print file, retrieved when the printer is ready to accept the job.
Once the job finishes printing, the system removes the print queue entry and
returns the space used by the print file. The system holds print files in the print
queue if the assigned printer is not available.
9-4
In addition, the system can maintain output from an account as a hold file. A hold
file is a print file with a ‘hold' status. It remains on the print queue, regardless of
whether the system prints the job or not. You must delete hold files explicitly
from the queue when you no longer need them. You use SP-ASSIGN to specify
that you want to retain spooled output as a hold file. You use SP-EDIT to
manipulate hold files on the queue. It allows you to examine, print or direct to
tape any hold file on the screen. In addition, you use SP-EDIT to delete hold files
or direct them to a form queue different from the one specified originally.
SP-KILL can only cancel a job printing currently. You must convert print files not
printing in the queue into hold files using SP-KILL; only then it is possible to
manipulate them. That is, you cannot view or delete a print file unless it has a hold
status. You must make it a hold file and use SP-EDIT to perform those tasks.
Command Summary
This section covers many commands used to affect the operation of the Spooler or
to report on its status. The UniVision Command Reference Guide describes the
following commands in detail.
STARTPTR
Initialises or restarts a system printer.
:STARTSPOOLER
Restarts the Spooler without restarting the entire system.
LISTABS
Lists the current Spooler assignments for all lines on the
system.
LISTPEQS
Lists the status of the print files and hold files managed
currently by the Spooler.
LISTPTR
Displays information about system printers.
SP-ASSIGN
Directs and controls output sent to the printer and assigns a
form queue to a process.
SP-CLOSE
Closes the print file.
SP-COPIES
Allows administrators to modify Spooler records
SP-EDIT
Manipulate Spooler hold files
SP-ENABLE
Allows users to restart the printer.
SP-KILL
Stops a current print job from printing, removes a printer
from the system, and makes print files into hold files.
SP-OPEN
Opens a single print file for several consecutive print
requests.
SP-STATUS
Lists current status of all system printers.
The Spooler
9-5
SP-TAPEOUT
Copies the contents of a print file from tape to a print file on
the Spooler.
STOPPTR
Stops one or more printers after the current print job, if any
have finished printing.
Summary of Spooler Features
The following summarises the Spooler features:
•
It maintains up to 9999 print files on the queue.
•
It assigns up to 1000 form queues across the system.
•
A single print request can generate 999 copies.
•
It supports up to 1000 printers: this can be a mixture of parallel and serial
printers, for example 800 serial and 200 parallel.
Printer Administration
The system administrator is responsible for system-wide tasks such as installing
new printers and adding them to the system configuration. These tasks allow the
Spooler to operate efficiently for all users. The administrator generally controls:
•
Installing and configuring printers.
•
Restarting inoperative printers.
•
Removing printers from the system.
•
Inspecting status of printer and the Spooler print queue.
This section, reviews these tasks in brief. This should familiarise you with the
operation of the Spooler and the configuration of system printers. For a more
detailed description of printer installation and startup, refer to the UniVision
Starting the Spooler
st
The UniVision Spooler process starts automatically when the 1 user logs in to the
UniVision environment. In addition, you can restart the SS process by using
:STARTPOOLER without having to log everyone out of UniVision.
For printers to work in UniVision you must have set the printer up in the operating
system. The remainder of this section is an outline of specific UniVision spooler
commands. For detailed information on setting up printers in the operating
system, refer to the manuals that came with the operating system software.
9-6
For more information on setting up printers for use with UniVision, refer to the
UniVision System Administration Guide.
Configuring Printers (STARTPTR)
STARTPTR initiates or restarts a system printer. In addition, you can use
STARTPTR to assign form queue to a printer and to specify the following printer
information: the number of pages the printer is to skip between print files, the type
of printer, and the number of the assigned process for the printer.
The syntax for STARTPTR is as follows:
STARTPTR printer[,form,skip,type-process, [options]]
printer
number of the printer, can be any number from 0 to 999. You
must enter a printer number.
form
form queue number, can be any number from 0 to 9999. You
require the form queue number when initialising a printer.
skip
number of pages to skip between print files, can be from 0 to
9 pages.
type-process
specifies two things: the printer type and the process number
assigned to the printer. Do not separate type and process with
a comma. The type can be P (parallel) or S (serial). The
process number can be any valid line (process) number for
serial printers, or the physical device number (0, 1, 2, etc.)
for parallel printers.
You must enter parameters in the exact order shown, separated by commas where
indicated.
options
The Spooler
A
begins the alignment process. There must be a
print job waiting in the queue in order for the
alignment process to work.
S
specifies that the printer is to ignore the form-feed
command at the beginning of a print file. Use this
option when you have set skip to a number other
than zero. Not available with parallel printers.
U
starts external spooler.
9-7
Initialising a Serial Printer
>STARTPTR 1, 1, 0, S8
Shows how to use STARTPTR to initialise a serial printer.
The system assigns Printer 1 to form queue 1, skipping 0 pages between print
files, and it is a serial printer assigned to process 8.
If you attempt to start a printer not defined in Uvsetup, for instance.
>STARTPTR 0,0,0,S4
The system displays the following message:
UniVision process #4 is being used by a VDU or is not available
for use as a printer
If you attempt to specify too many spool queues, for instance:
>STARTPTR 0,(1,2,3,4)
The system displays the following message:
Too many UniVision Print Files
Initialising a Parallel Printer
>STARTPTR 1,1,0,P1
The UniVision printer control block has been initialised.
Check that there is paper in the printer,
and the current lpi is set.
>SP-ASSIGN F1
>PRINTRONIX 66
Entry #nn
Shows how to use STARTPTR to initialise a parallel printer.
The system assigns printer 1 to form queue 1, skipping 0 pages between print
files, and it is a parallel printer assign to process 1.
Changing a Printer’s Form Queue
>STARTPTR 1,(1,5,6)
Shows how to assign multiple form queues to a printer already started.
9-8
The system assigns printer 1 form queues 1, 5, and 6.
The system print jobs in the order specified by STARTPTR. In the example, the
system prints any jobs in forms queue 1 first, followed by any jobs in forms queue
5, and finally any jobs in forms queue 6.
Restarting a Stopped Printer
Restarting a stopped printer is the simplest form of STARTPTR. Use this form of
STARTPTR to restart a prints after a stop. All other processes remain unchanged.
>STARTPTR 1
To see the configurations for printers, use LISTPTR, described later.
Restarting a Failed Printer
You use SP-ENABLE to restart a UniVision printer and re-enable UNIX printers
after you have encountered a UNIX printer or spooler failure.
! Note:
You cannot use SP-ENABLE until you resolve all your
UNIX printer or spooler problems.
Checking the Status of Printers (LISTPTR)
You use LISTPTR to obtain information about printers. For each printer the report
lists:
•
Printer type.
•
Form queues assigned.
•
Number of blank pages skipped between print jobs.
•
The device number (if a parallel printer) or the number of the line
attached to the printer (if a serial printer).
•
The current status of the printer, ACTIVE, INACTIVE, STOPPED
ACTIVE, STOPPED INACTIVE, DISABLED or UNALLOCATED.
The syntax is:
LISTPTR [n[-m]][options]
n
number of the printer.
n-m
range of printer numbers.
options
can be one of the following. You do not need parentheses:
B
The Spooler
lists information about all printer control blocks,
whether allocated or not.
9-9
N
suppresses automatic paging.
P
sends output to the printer.
U
displays the UNIX printer name, and if the system
has set the 'suppress initial form feed' option of
STARTPTR it displays a (s next to the Page Skip
setting.
LISTPTR produces a report that looks like this:
UniVision Printer Assignments
Printer
Type
Number
Output Queues
PARALLEL
PARALLEL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
0
2
3
4
5
6
7
16:25:34
Page
Skip
Dev Or
Process #
0
0
1
1
1
1
1
0
2
8
70
63
53
13
0
1
3 7 8
4 7 8
5
6
2
Status
ACTIVE
INACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
The report generated lists the following information:
Printer Type
PARALLEL or SERIAL.
number of the printer. Used by STARTPTR, STOPPTR, and
Number
SP-KILL.
Output Queues
form queues attached to the printer currently.
Page Skip
number of pages you want to skip between each print job.
Dev or Process#
number of the process attached to the printer, or the parallel
printer device number.
Status
ACTIVE, INACTIVE,
DISABLED.
STOPPED,
UNALLOCATED,
or
LISTPTR with a U option produces a report such as the following:
Number
3
Printer
Uvepson
Output Queues
3
16:41:16
Page
Skip
Dev Or
Process #
Status
1 (s
8
ACTIVE
>
9-10
LISTPTR with the B option produces a report such as the following:
Printer
Type
Output Queues
Number
PARALLEL
SERIAL
PARALLEL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
SERIAL
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16:35:54
Page
Skip
Dev or
Status
Process #
0
0
0
1
3 7 8
4 7 8
5
6
2
0
1
1
1
1
1
1
8
70
63
53
13
ACTIVE
UNALLOCATED
INACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
UNALLOCATED
UNALLOCATED
UNALLOCATED
UNALLOCATED
UNALLOCATED
UNALLOCATED
UNALLOCATED
UNALLOCATED
>
Stopping Printers (STOPPTR)
The printer has several states:
ACTIVE
The printer is currently printing a job.
INACTIVE
The printer is available for printing.
STOPPED
The printer has stopped in UniVision and does not send print
jobs to the operating system.
UNALLOCATED
You have deleted a printer defined previously in the
operating system.
DISABLED
The operating system has disabled the printer. This printer
does not accept print jobs.
STOPPTR stops one or more printers after the current print jobs, if any, have
finished printing. STOPPTR requires SYS2 privileges as it affects a system
resource available to all users. Usually you stop a printer prior to removing the
printer from the system, since STOPPTR allows the current print job to finish
first.
The syntax is:
STOPPTR [n[-m]][B][W]
The Spooler
9-11
n
number of the printer you want to stop. If you do not specify
a printer, the system stops printer number 0.
n-m
range of printers you want to stop.
B
stops all printers.
W
causes the process to wait until the printer is inactive before
it returns the terminal to the UCL prompt, EXECUTE or
Proc.
Stopping a printer tells the Spooler that the printer is off-line. If you stop a printer
successfully, the system displays the following message:
Printer #n Changed to Stop And Is Inactive
where n is the printer number. If the printer is still printing, the system displays
Printer #n Changed to Stop But Is Still Active.
Once the current file has finished printing, the printer becomes inactive
The W option is useful when you are using certain Procs to handle the Spooler.
For example, since STARTPTR does not work if the printer is still active, you
should always use STOPPTR with the W option before using STARTPTR to
ensure that the printer is inactive before the process returns to the Proc.
Once the printer is inactive, it is safe to remove it from the system using SP-KILL
with the D option. You require SYS2 privileges to use this option. You can use
SP-KILL to remove a printer no matter what state it is in. However, recommended
practice is, to remove the printer only when it is inactive. The following example,
removes system Printer 1 from the system.
>STOPPTR 1
Printer #1 Changed to Stop And is Inactive
>LISTPTR 1
Printer
Type
Number
Output Queues
SERIAL
1
0
11:10:09
Page
Skip
1
Dev or
Status
Process #
10
INACTIVE
>SP-KILL D1
Serial Printer #1 Has been deleted for UniVision
The message indicates SP-KILL has removed a serial printer.
Use STARTPTR, to restart the printer.
9-12
Assigning Spooler Specifications (SP-ASSIGN)
SP-ASSIGN directs and controls output sent to the Spooler and to assign a form
queue to a process. SP-ASSIGN determines what the current spooler assignments
are and specifies the number of copies you want to print, print job priority and the
destination of the print job.
The syntax is:
SP-ASSIGN [options]
options
can be any combination of the following, details about each
option follow the list:
?
displays current SP-ASSIGNments.
n
assigns number of copies you want to print, You
can assign up to 999 copies.
A
prints jobs on the Auxiliary port of the terminal.
B
prints a print banner at the beginning of each print.
C
chokes printer output to the speed of the printer.
You must use the C option with the I option.
Ignored by UniVision.
Fform
assigns a specified form queue to user's process,
any number from 0 to 125.
H
saves output as hold file.
I
specifies immediate printing that is puts file to
front of queue.
O
keeps print files open, allowing multiple print
requests to be processed as one print job.
Rpfile
reassigns print file generated by UniVision
BASIC PRINT ON statements.
S
suppresses printing of a print job. Normally used
with the H option.
T
sends output to the tape device. You require SYS1
privileges to use this option.
You do not need to enclose options in parentheses, can enter them in any order,
and need not separate them with spaces or commas.
When you install the system initially, it sends all printer output, by default, to
form queue 0 and sets the number of copies to print to 1. To see a list of current
SP-ASSIGNments for all processes, use LISTABS.
The Spooler
9-13
Users can change their queue assignments and output specifications for their own
processes at any time with SP-ASSIGN. Any changes made remain in effect until
the user logs to another account or logs off. To reset the SP-ASSIGNments to the
original default options, use SP-ASSIGN with no options.
In addition, you can place SP-ASSIGN in a Logon Proc for the account. This
ensures that the system establishes the assignment each time the user logs on. This
is necessary only if you want to maintain a form queue assignment other than the
default.
Listing the Assignments Status (?)
The ? option displays the current status of SP-ASSIGN for the user's process. The
report is similar to the following:
>SP-ASSIGN ?
Process
Status
0012
P
Cop
ies
UniVision
Form Queue#
1
0
>
Status codes that correspond to SP-ASSIGN options can be any of the following:
H
Output to a hold file.
I
Print immediately, that is, put file to front of queue.
O
Keep print file open.
P
Output to the printer.
T
Output to tape.
Selecting the Number of Copies (n)
The n option assigns the number of copies you want to print. If you do not specify
n, the system prints one copy. When you assign multiple copies, the system does
not release the print file until it has printed the last copy. If you use the T, tape,
option, the system ignores the n option.
The following example assigns the number of copies you want to print to 20:
>SP-ASSIGN 20
Process
Status
Cop
ies
0012
P
20
UniVision
Form Queue#
0
>
9-14
Print to Auxiliary Port (A)
The A option allows a UniVision process to send its print jobs to the Auxiliary
port of the terminal. It is possible to combine this option with the S, T and H
options of SP-ASSIGN.
Print Banner (B)
The B option prints a banner at the beginning of each print file. It is possible to
customise the banner, defined in the ERRMSG file in an item called
PRINTBANNER.
Form Queue (F)
The Form option assigns a form queue to the user's process. When you install the
system initially, all processes have form queue 0 assigned to them. When users
change their form queues, these assignments remain until you change them
explicitly using SP-ASSIGN, or until the user logs to another account or logs off.
If you send output to a tape device, the system ignores the F option.
>SP-ASSIGN F3
Process
Status
Cop
ies
0012
P
1
UniVision
Form Queue#
3
>
Destination Options (H, S, T)
The H option creates a hold file. If you use the H option with the S option, the
system creates a hold file but sends nothing to the printer. The H option is useful
when you want to save print jobs until it is more convenient to print them, or
when the system administrator needs to change the type of paper in the printer.
>SP-ASSIGN HS3
Process
Status
Cop
ies
0012
H
3
UniVision
Form Queue#
0
>
Saves the print job as a hold file; the S option prevents the print job from being
sent to the printer. When you remove the hold, the system sends the print job to an
available printer assigned to form queue 0. The system prints three copies.
The Spooler
9-15
If you use the T option without the S (suppress printing) option, the system sends
the output to a tape device as well as to the printer. The system sends output to the
tape wherever the current position is. The tape-unit does not rewind automatically,
so you can send print files to the tape one after another. You require SYS1
privileges to use this option.
! Note:
Ensure that you have a tape drive attached, T-ATT, and
have the proper tape-unit selected, T-SELECT.
If you use the T option with the S option, the system sends output to the tape
device, but sends nothing to the printer. If you use the T option with both the S
and H option, the system sends output to the tape device and creates a hold file,
but sends nothing to the printer.
The S option suppresses printing and normally you use it with the T, tape, and H,
hold file, options. When you use the S option, the system does not enqueue the
print file for printing.
>SP-ASSIGN TS
BLOCK SIZE: 500
Process
Status
Cop
ies
0012
T
1
UniVision
Form Queue#
0
>
Directs output directly to tape, by-passing the Spooler, the S option suppresses
printing, and displays the current SP-ASSIGNments.
Selecting Job Priority (I)
The I option starts the print job as soon as possible. This option assigns a higher
priority to the job, causing the system to process it before other jobs. When you
use the I option, the Spooler finishes any jobs currently active, before it
‘immediately’ processes the requested job. The system processes I-jobs in the
order in which you enter them. If you use the T, tape, the H, hold file, or the S,
suppress printing options, the system ignores the I option.
The following example assigns form queue 1 to process 12 and specifies that the
system should handle subsequent print jobs immediately, once the printer is free.
>SP-ASSIGN F1I
Process
Status
Cop
ies
0012
PI
1
UniVision
Form Queue#
1
>
9-16
Open Option (O)
The O option keeps a print file open until you close it explicitly. The O option is
useful when you want to collect output from multiple print requests and print it as
a single print job. The system prevents all other print jobs from printing until you
close the print file, however, it continues to spool the print jobs. Remember to
close the O option setting after you use it, by re-executing SP-ASSIGN without
the O option. In addition, using SP-CLOSE or logging off closes an open print
file.
>SP-ASSIGN HSF20
Process
Status
Cop
ies
0012
H O
1
UniVision
Form Queue#
2
>SORT ORDERS WITH DATE >= "05/01/95" AND DATE <= "05/31/95" (P)
HOLD ENTRY #24
>SP-ASSIGN HSF2
[1140] Your Open UniVision Spooler Files Were closed
Process
Status
Cop
ies
0012
H
1
UniVision
Form Queue#
2
>
Creates a hold file using form queue 2, leaves the print job open and displays the
current SP-ASSIGNments. The system sends several print requests, and you close
the print job by re-issuing SP-ASSIGN without the O option.
Reassigning Print Files (R)
You use the R (Reassign) option in conjunction with PRINT ON pfile in a
UniVision BASIC program. This option reassigns the print files generated by a
PRINT ON. Use R together with other SP-ASSIGN options to customise the SPASSIGN options for the reassigned print file. They do not change any of the
current SP-ASSIGNments, nor do they affect the options assigned to any other
reassigned print file by the R option.
The Spooler
9-17
>SP-ASSIGN F3HR3?
Process
Status
Cop
ies
0012
H
10
UniVision
Form Queue#
3
>
Allows the system to generate a print job by a PRINT or PRINT ON 3 in a
UniVision BASIC program. The system makes the print job into a hold file, prints
a single copy using form queue 3, and displays the current SP-ASSIGNments
Checking the Print Queue
Use LISTPEQS when you require information about print jobs and hold files
currently by the Spooler. The syntax is:
LISTPEQS [n[-m]] [account] [options]
n
number of print file.
n-m
range of print file numbers.
account
displays all print files generated by the specified account.
You must enclose the account name in single or double
quotes. You require SYS2 privileges to use this option.
options
A
lists only those print files generated by the current
logon account.
C
lists only the total number of print files and the
total amount of space they use.
E
lists the UNIX filename of the specified print
files.
F
lists print jobs in order, firstly by form queue, then
by the order in which the system lists them. The
system does not list hold files.
L
lists obsolete print files already deleted, in
addition to active print files.
P
sends the report to the printer
If you do not specify any options, the system lists the status of all print files.
LISTPEQS produces a report similar to the following:
9-18
PRINTER LIST ELEMENTS
#
LK
1
2
3
4
5
6
7
8
9
10
11
12
13:49:17 14 JUL 1993
LN
STATUSES
CP
FO
SIZE
DATE
TIME
ACCT
11
1
5
0
5
5
11
11
11
11
11
11
HP C
HP C
H C
HP CR
H C
P C
H C
HP C R
HP C XR
HP C
H L
HP C XR
1
1
1
1
3
1
3
1
5
1
3
1
4
4
0
0
0
0
0
0
1
4
0
0
261
575
37
81
4
OPEN
1
30
21
420
OPEN
19
06/22/88
06/23/88
07/13/88
07/13/88
07/14/88
07/14/88
07/14/88
07/14/88
07/14/88
07/14/88
07/14/88
07/14/88
11:54:34
10:37:09
12:46:00
14:12:28
13:14:49
13:17:48
13:21:00
13:24:10
13:26:18
13:27:15
13:29:52
13:30:03
TSB
TSB
MANUALS
SYSPROG
DP
MANUALS
DP
SYSPROG
DP
TSB
DP
CAROL
12 QUEUE ELEMENTS
1449 BYTES USED
>
All jobs except for entry 6 are hold files. These hold files remain on the Spooler
even after the system has printed the jobs. The system has not scheduled entries 3,
5, and 7 for printing currently. Entries 6 and 11 are both open print jobs, which
means they are locked files that are not accessible by SP-EDIT. Once you close
these files, however, you can use SP-EDIT on these files. SP-EDIT has edited
entries 4, 8, 9, and 12. Of these four entries, the system has only spooled 4 and 8
completely to the printer; it has cancelled entries 9 and 12 during output by SPKILL.
The report contains the following information:
#
print file number, sometimes called the entry number.
LK
forward link, showing the sequences in which the system
prints the jobs. Only shown if it is non-zero.
LN
number of the line, process, on which the system generated
the print file or of the hold file being edited.
STATUSES
status of the print file. For details on status codes see below.
CP
number of copies.
FO
number of the UniVision form queue.
SIZE
number of bytes of a closed print file; the system displays the
word OPEN if the print file is open.
DATE
date when the system queued the print file.
TIME
time when the system queued the print file.
ACCT
name of the account that generated the print file.
The Spooler
9-19
The codes in the STATUSES column indicate the following:
Destination
G
Print file is the alignment segment of another print file.
When you use the A option of STARTPTR, the system
generates a special print file used only for aligning the
printer.
H
File is a hold file. The system creates hold files because of
their SP-ASSIGNments; because the F option of SP-KILL
dequeues them; or because a cold start has occurred.
I
Print the print file immediately, specified by SP-ASSIGN
with the I option.
P
The system is to send the print file to the printer.
T
The system is to send the print file to the tape drive.
Open, Spooled, or Currently Being Printed
N
The system generated a print file under an SP-OPEN
condition. Open files are not available to SP-EDIT.
S
The system has spooled the print file to a form queue using
SP-EDIT. Such spooled files are no longer available to SPEDIT.
O
The system is printing the print file currently. Files being
printed currently are not available to SP-EDIT.
L
The system has locked the print file. The system locks file
when they are available, open, spooled, being printed, or
being edited. Locked files are not available to SP-EDIT.
Closed or Edited
C
Print file is closed. If C does not appear, the print file is
being printed currently or in an SP-OPEN condition.
R
The system has edited the print file and sent it to the printer.
Cancelled
X
9-20
The system killed the print file using SP-KILL.
A
Printer control block is available for re-use. The system does
not create any new control blocks for print files until it has
re-used the existing ones. The system encloses all other
status codes for these obsolete print files in parentheses.
Files in available control blocks are not accessible to SPEDIT.
LISTPEQS has several options that allow you to show hold files only (H), show
entries for your account (A) and sort pending jobs by form queue (F). Refer to the
UniVision Command Reference Guide for more information.
Cancelling Print Jobs
SP-KILL has many uses, some of which should be limited to the administrator.
Use SP-KILL to stop a current print job from printing or to turn print files into
hold files. As mentioned earlier in the section Spooler Administration, you use
SP-KILL to remove a printer from the system.
Cancelling an Active Print Job
SP-KILL used with a printer number cancels a print job being printed currently:
SP-KILL n[-m] [A][B][N][O]
n is the printer number, and you must specify at least one printer number When
you use SP-KILL to cancel a job printing currently, the Spooler stops sending data
to the printer immediately. However, the printer continues printing whatever still
remains in the print buffer before it stops. If you do not use the N option, the
system prints the print the ABORT message on the next line after the point where it
cancelled the report.
If you use the A option, the system cancels all print files created on the current
logged on account if they are being printed currently.
If you use the B option, the system cancels all print file being printed currently.
You require SYS2 privileges to use this option.
If you use the O option, the system cancels the report being printed currently and
makes the print file into a hold file.
>SP-KILL 3
Cancels the print job going to printer 3. The system prints the message ABORT! on
the page at the point where the cancellation takes effect:
>SP-KILL 3N
The Spooler
9-21
Cancels the print job going to printer 3, but the N option suppresses the ABORT
message.
>SP-KILL 3-5
Cancels print jobs going to Printers 3, 4, and 5:
Exactly when an active print job stops depends on how large a buffer the printer
has and how much data the system was able to send it before it received the abort
message. Killing a print job does not stop the printer; it simply tells the system to
stop sending data from that print file to the printer. As soon as the printer buffer
empties, the printer stops printing the current job and begins to print the next job
in its queue. The system delete the cancelled print file from the print queue if it is
not a hold file.
Retaining Print Files as Hold Files
SP-KILL used with the F option removes print files from the queue and turns them
into hold files:
SP-KILL Fn [-m] [A][B][O]
where n-m is the number or range of numbers of entries in the form queue. You
must specify at least one print file with the F option. Use LISTPEQS to list the
print files. When you remove a print file from the queue, it becomes a hold file,
which is available for further processing by SP-EDIT.
The F option does not remove a print file from the queue and make it a hold file if
the file is being printed currently.
If you use the A option, the system removes all print files created on the current
logged on account from the queue.
If you use the B option the system removes all print files from the queue.
>SP-KILL F5
Removes print file 5 from the queue and makes it a hold file.
>SP-KILL F5-9A
Removes any print files from 5 to 9 generated from the current logged on account
and makes them hold files.
Removing Printer from the System
SP-KILL used with the D option removes printers from the system:
SP-KILL Dn[B]
9-22
You must specify at least one printer number with the D option.
It is not a good idea to remove a printer from the system while it is running. If you
want to remove an active printer, first stop the printer using STOPPTR, and use
SP-KILL n, to cancel the current print job, if there is one, and remove the printer.
When you remove a parallel printer, it becomes inactive. When you remove a
serial printer, the attached line, process, becomes a normal communications line.
If you use the B option together with the D option, the system removes all printers.
Removing Printers
>SP-KILL D1
SERIAL PRINTER #1 HAS BEEN DELETED, AND ITS PROCESS SET TO LOGON
Removes printer 1 from the system.
>SP-KILL D3-5
Removes printers 3,5 and 5.
>SP-KILL DB
Removes all printers from the system.
Manipulating Hold Files
The print queue consists of two types of file: print files and hold files. SP-EDIT
manipulates Spooler hold files. SP-EDIT can:
•
display and print all or part of any hold file.
•
redirect a hold file to another printer or to a tape device.
•
convert a hold file into data file items.
•
delete one or more hold files from the Spooler.
If you invoke SP-EDIT without any arguments, it selects all the hold files
generated from your own account. A set of command line options allow you to
select hold files by number, by account, or by form queue.
For each of the selected hold files, SP-EDIT prompts you for the appropriate
action to take. There are actually four prompts that SP-EDIT uses to prompt for
input. These following summarises the prompts in the order in which you
generally encounter them:
The Spooler
9-23
DISPLAY
Display the first 500 characters of the hold file.
STRING
Specifies that printing of a hold file start at first line
matching a string.
SPOOL
Spools the hold file for printing, displays the file on the
screen, or converts the file to a data file items.
DELETE
Delete the hold file.
Figure 9-3 summarises the responses at each prompt and how you can move from
one prompt to the next. In addition, a group of command line options exist that
avoid the prompting sequence and allow you to invoke SP-EDIT to perform a
specific function.
9-24
DISPLAY
Y
Displays first part of file and prompt for STRING
N
Skip to STRING prompt
S
Skip to SPOOL prompt
D
Skip to DELETE prompt
X
Exit SP-EDIT
Return
Skips to next hold file, if any
String
Move to first line containing STRING
if not found, prompt again
STRING
Return
Skip to SPOOL prompt
Y
Release hold for printing or for tape drive
N
or
SPOOL
Return
Skip to DELETE prompt
T
Displays entire hold file on screen
F
Converts hold file to data file item
Y
Delete hold file
DELETE
N
or
Return
Select next hold file
Figure 9-3.
SP-EDIT prompts and responses
The Spooler
9-25
! Note:
The responses to the SP-EDIT prompts must be in uppercase. The system ignores any response in lower-case.
Viewing the Contents of a Hold File
When you enter SP-EDIT, the system displays the following prompts:
>SP-EDIT
UniVision Spooler Entry # nnn
DISPLAY (Y/N/S/D/X(CR))?-
nnn is the number of the 1st hold file selected. the prompt allows you to display
the first 500 characters of the hold file. If you want to display the entire hold file,
skip to the Spool prompt and enter T or TN.
Responding to the ‘Display’ Prompt
At the Display prompt, enter one of the following:
Y
displays the file.
N
skips to the String prompt.
S
skips to the Spool prompt.
D
skips to the Delete prompt.
X
exits SP-EDIT and returns to the UCL prompt.
<RETURN>
skips to the next hold file, or if there are no more selected, to
the calling process, the UCL prompt, a Proc, or a UniVision
BASIC program.
Any other response skips to the String prompt.
When you select Y the system displays the first 500 character of the hold file. If
the 500 characters appear in the middle of a line, the system displays the
remaining character in the last line, and displays the String prompt.
If the system is printing the hold file you want to displays currently, use the O
option of SP-EDIT to displays it. If you do not use the O option, the system
displays the following message.
ENTRY # n IS NOT AVAILABLE
and the process continues to the selected hold file or, if there are none, to the UCL
prompt. To proceed to the next file, press <RETURN> at the NEXT? prompt.
If you included the L option when you entered SP-EDIT initially, only three
responses to the Display prompt are possible.
9-26
<RETURN>
skips to the next hold file.
X
exits SP-EDIT and returns to the UCL prompt.
other
any other response displays the beginning of all hold files
that are not being printed currently.
Responding to the ‘String’ Prompt
The String prompt looks like this:
STRING:-
The String prompt allows you to start printing a hold file from any line in the
file. You can identify the line by specifying a unique string of character contained
in the line from which you want to start.
One of two responses is possible here: entering a character string, or skipping to
st
the Spool prompt. To move to the 1 occurrence of a character string in the hold
file, enter the character string at the prompt. If the system finds the string, SPEDIT moves the beginning-of-report address to the line containing the character
string, and displays the Spool prompt. If the system does not find the string it
displays the following message.
STRING NOT FOUND
STRING:-
and you can try again. To skip the String prompt altogether, press <RETURN>.
The system displays the Spool prompt.
Responding to the ‘Spool’ Prompt
The Spool prompt allows you to spool the hold file for printing, print the file on
your screen, or convert the file to a data file. The Spool prompt looks like this:
SPOOL (Y/N=CR/T/TN/F)?-
Enter one of the following:
Y
releases the hold file for printing or sends it directly to a tape
device, depending on the currently active options.
N
<RETURN>
T
displays the entire hold file on the screen.
The Spooler
9-27
displays the entire hold file on the screen and suppresses
automatic paging.
TN
converts the hold file to a data file item, or series of items, in
F
RUNOFF format.
The following sections describe each of these responses in detail.
Spooling a Hold File
If you select Y and the system cannot spool the hold file, it displays the following
message:
Your specification is not output
Reassign your process if you want to output a Hold file
END OF PRINT FILE CONTROL BLOCK
and the system returns you to the UCL prompt. You can modify the SPASSIGNments to allow spooling of the file, and re-enter SP-EDIT to spool the
file.
Printing a Hold File on the Screen
If you select T to display the entire contents of the file on your screen, the system
st
displays the 1 page. You can enter any of the following:
U
repeats the current page.
T
causes output to start from the top.
X
exits the displayed page and return you to the Spool prompt.
Any other character displays the next page.
These three option are not available if you use the TN option.
Converting a Hold File to a Data File
If you use the F option , the following prompt appears:
FILE NAME:-
Enter the name of the data file to which you want to transfer the hold file, and the
following prompt appears:
INITIAL ITEM:-
Enter the name of the item.
! Note:
9-28
If the item exists, this option overwrites it.
The system converts the hold file into an item in the file you specified.
If you include the V option when you enter SP-EDIT initially, the system retains
all trailing blank lines in the data item.
Responding to the ‘Delete’ Prompt
The Delete prompt allows you to delete a file from the Spooler. You must make
a print file into a hold file before you can delete it. The Delete prompt looks like
this:
DELETE (Y/N=CR?
Enter Y to delete the specified hold file. Enter N to skip to the next specified hold
file.
Selecting Hold Files
The section shows some of the ways to select a file you want to edit. Normally
SP-EDIT selects the hold files associated with an account. It is possible to select,
all hold files system wide, or hold file in the account assigned to a particular form
queue.
The U option selects all available hold files, whether generated by the current
account logged on or not.
>SP-EDIT U
UniVision Spooler Entry #1
DISPLAY (Y/N/S/D/X/(CR))?
The system displays a prompt for each selected hold file unless you enter X to exit
at Display prompt.
You can specify hold file generated in another account by specifying the name of
the account enclosed in quotes. The following example selects all hold file
generated in the SALES account:
>SP-EDIT ‘SALES’
The Fn option restricts selection to a form queue n, or to a range of form queues,
n-m. The following example selects all hold file generated on the current account
sent to form queue 1.
>SP-EDIT F1
It is possible to combine these option. For instance, UF1 selects all files systemwide sent to form queue 1.
The Spooler
9-29
Spooling and Deleting Multiple Hold Files
You use the MS and MD options to avoid being prompted for each of the selected
hold files individually. The MS option spools all selected print files to the form
queue specified originally. The MD option deletes all selected print file.
The following example sends all hold file created by the account SALES to form
queue 4.
>SP-EDIT F4MS ‘SALES’
The next example deletes all hold file created on any account sent to form queues
1 or 2.
>SP-EDIT UF1-2MD
Modifying Spooler Records
The UniVision administrator can use SP-COPIES to modify a spooler record for a
specific spooler entry.
It syntax is:
SP-COPIES entry copies
entry is the number of the spooler entry you want to modify and copies is the
number of copies you want the Spooler record to have.
SP-COPIES 4 3
Modifies Spooler entry 4 to have 3 copies.
Using the Spooler with Tape Drives
It is not possible to share a tape drive. Before you can direct any output to tape,
you must attach the tape drive using T-ATT. No other users can access the tape
drive while you have it attached.
SP-ASSIGN with the T option specifies that a tape drive services the output queue.
In addition, this option attaches the tape drive.
The system sends output to the tape at the current position. The tape unit does not
rewind automatically, so you can send print files to the tape one after another.
The following sets of options modify how the Spooler handles each subsequent
print job:
9-30
T
Send output to tape drive as well as the printer.
TS
Send output to tape but not to the printer.
THS
Send output to tape and retain as a hold file but do not print
the job.
The following example directs output directly to tape, by-passing the Spooler (the
S option suppresses printing).
>SP-ASSIGN TS
DEVICE ATTACHED BLOCK SIZE: 16896
Process
Status
Cop
ies
0012
T
1
UniVision
Form Queue#
0
Sending a Hold File to Tape
It is possible to send hold files to tape using SP-EDIT with the T option. SP-EDIT
writes to tape using the default block size. Do not change the block size between
requests without writing a new tape label.
You can use the following SP-EDIT options with the T option:
H
Suppress tape label.
W
Wait for tape drive to become available. Without this option,
the request fails if the tape drive is not available.
MS
Sends selected hold files to tape without prompting
individually for confirmation.
The next example sends all hold files between numbers 7 and 11 generated on the
logged on account, to tape:
>SP-EDIT 7-11 TS
Copying a Print File from Tape
SP-TAPEOUT copies the contents of a print file from tape and places an entry for
it in the print queue. The Spooler processes the file according to the SPASSIGNments set currently.
SP-TAPEOUT has a number of options that specify the formatting of data:
The Spooler
9-31
A
converts data in EBCDIC format on the tape to ASCII
format, and transfers the data to the Spooler print file.
U
converts alphabetic characters from lower-case to uppercase, then transfers the data to the Spooler print file.
SP-TAPEOUT executes T-ATT and transfers the contents of a print file to the
Spooler. It does this by having the Spooler create a print file and transferring the
print file from tape to the print file on disk. The system prints the file in
accordance with the current SP-ASSIGNment.
Using Procs for Printer and Tape Control
It is possible to control the Spooler system to some extent from a Proc (refer to the
UniVision PROC Reference Guide for detailed information on the PROC
processor). A Proc can use information in the secondary input buffer supplied by
the ERRMSG processor and by the Spooler. All verbs that use the ERRMSG file
place error message numbers as well. Sources other that the ERRMSG processor
can supply the following information to a Proc: the entry number for each print
file when initialised, data on the condition of the printers, and tape attachment
conditions for any process attempting to attach a tape drive.
You can inspect data in the secondary input buffer or transfer it to one of the
output buffers. You lose this data after the execution of a PROC P command. If
you expect particular pieces of information, you can define conditional statements
that perform some action on encountering the specified information.
The main uses of a Proc include: hold file retention, tape control, and printer
control.
Hold File Retention
If you execute an SP-ASSIGN H from a Proc, it leaves a mark with the print file
number in the secondary input buffer at the time when the system displays
ENTRY#. The mark is the ERRMSG number [1099]. If the process generates the
message:
HOLD ENTRY #17
and the PROC secondary input buffer contains:
1099 17
In addition, it contains any other error message numbers generated during
execution of the verb.
In the following example, a portion of a Proc retrieves a hold file entry number for
a succeeding SP-EDIT.
9-32
PROC Command
Explanation
P
SS
B
5 IF # A G 99
IF A1 = 1099 G 15
F
G5
15 F
IF A # (ON) G 98
HSP-EDIT
A
Execute the verb.
Set the buffer pointer to the secondary input buffer.
Backup input pointer.
End of buffer, entry not found.
Test for mark.
Advance the pointer to the next argument.
Test the next parameter.
Advance the pointer to the print file number.
Absent or spurious data.
SP-EDIT the print file.
Move the print file number to the primary output
buffer.
Turn on the stack for the prompts, as necessary.
Answer S to DISPLAY prompt.
Answer Y to the SPOOL prompt.
Process the SP-EDIT.
Normal exit.
Exit with error message.
Exit with error message.
STON
HS<<
HY<<
P
X DONE
98 XBAD DATA
99 XON DATA
Tape Control
Because it is not possible to share a tape drive, it is important to ensure that it is
available before you run any sequence of processes involving the tape drive under
PROC control. Procs cannot mount tapes or continue when the tape is inoperative.
The ERRMSG file contains the tape control error message numbers (90 to 99).
Certain tape difficulties are not amenable to PROC control because they interrupt
the process and speak only to the operator of the terminal. In these cases only user
intervention can correct the problem. Each time you use the tape, it is advisable to
attach it specifically using T-ATT. If the tape is available or already attached, TATT places 90 nnnn into the PROC secondary input buffer. Message [90] is a
mark that specifies that the system has attached the tape, and nnnn is the tape
block size. It is advisable to use an explicit block size with T-ATT, because there
might be times when the prior state of the process is unacceptable.
If the tape is not available, T-ATT inputs 95 nn into the PROC secondary input
buffer, where 95 is a mark indicating the tape is not available, and the string nn is
the number of the line the attached to the tape.
The following example uses SP-EDIT in a Proc that spools all selected print files
to tape automatically.
The Spooler
9-33
PROC Command
Explanation
P
SS
B
5 IF # A XXNO DATA
IF A1 = 1099 G 15
X NO PRINT JOB
15 F
IF A # (ON) X BAD DATA
HSP-EDIT
A
HMSTW
PP
Execute the verb.
Get the print file entry number
Put SP-EDIT entry.
Move the number
Wait until the tape is available.
This Proc yields SP-EDIT in MSTW.
Spooler Verb Input Conventions
Normally, you enter spooler verbs in free-form. There are input conventions that
you must follow, however, when you change this format. When you enter verbs,
the options, either individually or as a group, you might not have enclosed them in
parentheses. Often you only require a single left parenthesis. In the example
below, A, B, and C represent Spooler options.
>
>
>
>
>
>
VERB
VERB
VERB
VERB
VERB
VERB
ABC
(ABC)
AN(C
(A)B(C)
(ABC
A,B,C
If you place a number in an option string containing parentheses, the number must
precede the parenthesis or all of the options must be in parentheses. If you do not
use parentheses, the option can be in any order.
>
>
>
>
VERB
VERB
VERB
VERB
A B 3 C
3ABC
3 A (BC
(3ABC
If you use a pair of numbers to create a range, they must have the exact form n-m.
st
If you enter the pair in any other form, the Spooler ignores the 1 number and
retains the last number as a single parameter.
9-34
> VERB ABC 2-3
> VERB 2-3 (ABC
> VERB (ABC2-3
If you enter more than one number, or more than one pair of numbers, in the same
option string, the system only retains the last number or pair of numbers entered.
> VERB 2 ABC 3
> VERB 2-3 ABC 6
> VERB 2-3 ABC 4-5
implies >
implies >
implies >
VERB 3 ABC
VERB 6 ABC
VERB 4-5 ABC
When you use the 'account-name' parameter in an option string, you must
surround it with single or double quotes.
When you use the 'account-name' parameter with other options and use
parentheses, 'account-name' must precede all other options, and the other options
must be in parentheses. If you do not use parentheses, the options, including
'account-name', can be in any order. The system only accepts one 'account-name'
parameter in an option string.
> VERB ABC 3 'ACCOUNT-NAME
> VERB 'ACCOUNT-NAME' (ABC2-3)
> VERB 'ACCOUNT-NAME' (ABC 2-3)
The Spooler
9-35
Section 10
USING MAGNETIC TAPE
This Section covers the commands for writing and reading magnetic tapes. It
contains a tutorial for new users that introduces the fundamental commands, and
guides the user step-by-step through the process of creating a tape. In addition, it
describes how the system organises data on tape and introduces frequently used
terms. Subsequent sections describe various functions typically performed using a
tape drive in the UniVision environment.
Overview of UniVision Tape Operations
UniVision supports many different tape devices. The general rule is if the tape, or
tape like, device works in the operating system, you can set up the device and it
functions properly in the UniVision environment. Examples of such tape devices
that function properly in UniVision include devices such as:
•
½-inch tape drives.
•
¼-inch tape drives.
•
8mm tape drives.
•
4mm DAT tape drives.
Examples of tape-like devices include:
•
CD-ROM drives.
•
cartridge diskettes.
Usually, you do not use tape like devices in the same way you would use a tape
device. However, in the UniVision environment you can use these tape-like
devices in the same way you would use a normal tape device.
Throughout this Section system generating the examples has a quarter-inch
cartridge tape as its default tape device.
UniVision requires each tape device to have a logical tape unit number assigned
as part of the installation of the UniVision environment. The system administrator
performs these assignments using :INIT-TAPE. To setup any tape device for the
first time you must use the B option. To re-initialise existing tape devices requires
the I option.
Using Magnetic Tape
10-1
! Note:
To add a new tape device to an existing system you must
use the B intialise option, otherwise you do not see the
new device in the UniVision environment.
To change the default device number setup in :INIT-TAPE you must use SETTAPE. This allows you to re-order the tape devices so, for example, you can make
the normal backup tape drive device 0. device 0 is the default tape device and the
system attaches it automatically without the need to perform a T-SELECT before
attaching a tape device.
! Note:
It is not possible to attach a tape device if another user on
the system is using it.
For more information on setting up tape devices for use with UniVision, refer to
the UniVision System Administration Guide.
You must attach a tape device to your process before you can use it. Attaching the
tape drive gives the user exclusive control of the tape device. T-ATT attaches the
tape drive to the process issuing the command, if no other process or user is using
the device. The tape drive remains attached to the process until the user logs off or
detaches the unit by performing a T-DET.
To select a tape device other than the default you must use T-SELECT and specify
the device’s logical tape unit number. You can display a list of the available
devices by performing a T-STATUS. In addition, T-STATUS displays the fact of
whether another process has the tape device attached.
A number of tape utility commands attach the tape drive automatically if you have
not attached it already. However, it is a good idea to attach the tape drive as an
explicit step when accessing a tape drive, examples of commands that attach the
tape drive automatically include:
10-2
•
T-ONLINE
•
T-REW
•
T-EOD
•
T-ERASE
•
T-RDLBL
•
T-WEOF
•
T-WTLBL
•
T-WHAT
•
T-READ
•
T-RET
•
T-SPACE
•
T-DUMP
•
T-LOAD
Tape commands use the tape drive attached currently. If you have not selected one
the system uses the default device. T-SELECT allows you to select a tape device
other than the default.
It is possible to chain a series of tape devices together and select them for the
same process. The chain should only include devices of the same type, that is, all
half-inch tape drives or all quarter-inch tape drives. This allows continuous multist
reel tape operation using all the selected drives in sequence. When the 1 tape
drive in the series reaches the end of tape, the process rewinds the tape and begins
writing to the next selected tape drive. The system instructs the operator to mount
new tape media only when it reaches the end of the last tape on the last tape drive
in the series.
Writing and Reading Tape: A Tutorial
There are a number of commands that handle tape operations. You use some
frequently; others are more special-purpose and you use them in a particular set of
circumstances. This tutorial demonstrates how simple it is to write data to tape and
read files from tape. This tutorial has the following sections.
•
Accessing the tape drive.
•
Dumping a file to tape.
•
Restoring items from tape.
•
Appending data to tape.
•
Positioning the tape.
Accessing the Tape Drive.
In order to access a tape drive, you must attach a tape device. To see a list of
available tape devices on a system performs a T-STATUS. This displays all the
tape device defines currently in the UniVision environment. Included is the:
•
device number (LTU).
•
drive type.
•
process currently having the device attached, if any.
•
device description.
•
UNIX device name.
Using Magnetic Tape
10-3
>T-STATUS
LTU DRIVE
0
FO
1
D0
2
Q0
ATT
FORMAT
HIGH DENSITY
LONG LABEL
DEVICE DESCRIPTION
High Density (1.44M)
HPC1533A
Drive
UNIX DEVICE NAME
/dev/rdsk/f03ht
/dev/rmt/c0t4d0s0n
/dev/rmt/c0t6d0s0n
Before using a tape device you must attach it to your process. Use T-ATT to attach
a tape drive. You cannot attach a tape drive attached to any other process.
>T-ATT
BLOCK SIZE: 16896
Once you have selected a device, you can use T-WHAT to display the type of tape
device attached currently. Remember if you have not attached a tape device to
your process, T-WHAT is one of those tape commands that attaches the default
device automatically.
>T-WHAT
[6007] 1/4 inch cartridge unit
LONG LABEL
It is a good practice to always put a tape device on-line before performing a read
or write to tape. One way to put a tape on-line is to use the switches or buttons on
the device. Under software control, you can use T-ONLINE to put the tape device
on-line.
>T-ONLINE
BLOCK SIZE: 16896
[6004] tape on line
Sometimes it is necessary to retension quarter-inch, 8mm and 4mm DAT tapes.
You should retension a tape after many uses where systems do not utilise the
entire tape during a read or write pass. For example, a tape used once a week for a
full file save where the system does not write to the entire tape during the backup
is a good candidate for retension.
>T-RET
BLOCK SIZE: 16896
L 420 16:16:07 21 NOV 1996
A tape retension, fast-forwards to the end of the tape and rewinds. This action on
the tape media allows the tape drive to correct any bumps in the actual media. You
do not need to retension every time you use a tape. However, it is good practice to
do a retension on a tape that has infrequent use or rarely used completely.
10-4
Before you can write data to a disk, you must format the media. If you do not
format the disk, any tape function writing to tape formats it automatically. You
can use FORMAT in UniVision to perform a format. Formatting disks erases any
data contained on the disk.
>T-SELECT 1
[6037] Floppy device attached
>FORMAT
BLOCK SIZE: 500
>
! Note:
Formatted diskettes available on the market come with a
standard MS-DOS format. UNIX and AIX can usually
read and write to MS-DOS formatted diskettes.
However, on average it takes six times longer to write to
a diskette with MS-DOS format. It is recommended you
purchase unformatted diskettes and allow UniVision to
format the diskettes properly automatically. In addition,
you can use FORMAT to reformat MS-DOS formatted
diskettes. If you ever require to transport data to an MSDOS based system via diskette, make sure you do not
format the diskette on a UNIX or AIX-based system.
Any verb that attaches the tape drive also reports the block size. This is the fixedlength block, or physical record, used to store and retrieve data. You can find a
description of the block size, use the default at present, that is 16896 bytes for a
quarter-inch cartridge tape. An important but rather obvious step is that a tape
cartridge, reel or diskette must be located in the appropriate drive. For this tutorial
it does not matter whether the tape is new or not, as long as it is permissible to
overwrite any existing data on the selected media.
Dumping a File to Tape
This section describes how to make a tape containing the data from a single file.
You ‘dump’ the ORDERS file to tape using T-DUMP. This operation does not
affect the contents of the file, you can think of it as making a copy of the file and
placing it on tape.
The syntax is:
T-DUMP [DICT] filename [item-list] [selection] [HEADING “text”]
[modifiers] [(options)]
DICT
Specifies the file dictionary. When copying dictionary items,
T-DUMP does not copy any File Definition items to tape.
filename
Using Magnetic Tape
Name of the file.
10-5
item-list
List of individual item IDs. Enclose each item ID in quotes.
If you do not specify a list of item IDs, the system dumps all
items in the file.
selection
Specifies one or more conditions that an item must meet
before the system copies it. For a complete description of
selection expression syntax, refer to LIST in the UniVision
Command Reference Guide.
text
Added to the standard tape label via the HEADING modifier.
modifiers
Include one or more keywords that specify the report format.
These parameters affect headers, footer, spacing, totalling
column figures, control breaks, etc. For details refer to the
VISION Reference Guide.:
The following modifiers operate differently
HDR-SUPP
Suppresses creation of a tape label.
ID-SUPP
Suppress listing of item IDs during the copy to
tape operations
options
! Note:
Include one or more single character codes that specify the
report format and direct or modify output. You must enclose
them in parentheses, can enter them in any order, and need
not separate them with spaces or any delimiters such as
commas. For details refer to the VISION Reference Guide.
In addition, there is a ‘SORT’ version of T-DUMP called
S-DUMP.
In the following command, T-DUMP makes a tape containing the entire ORDERS
file:
10-6
>T-DUMP ORDERS
BLOCK SIZE: 16896
1
10107
2
10119
3
10110
4
10122
5
10113
6
10104
7
10116
8
10101
9
10134
10
10105
11
10108
12
10120
13
10111
13 Items dumped
The system dumped the 13 items in the ORDERS file to tape.
Once the UCL prompt returns, the system has completed the operation. It
positions the tape just after a mark known as the End-Of-File (EOF) mark. At this
point, you can rewind the tape drive using T-REW and detach it using T-DET, you
can remove the tape cartridge from the drive, and the system makes the tape drive
available to other users.
>T-DET
The system does not display a message if it detaches the tape drive successfully,
and you can remove the tape from the tape drive.
Some tape devices, such as half-inch, 8mm, and 4mm DAT tape drives can unload
the tape media under software control. T-UNLOAD can be used to rewind the tape
and unload the media from the drive. However, the device is still attached to your
process. When you have completed using the tape device you should detach the
drive or log off. Either action releases the tape device for use by another user
logged on to another process.
Restoring Items from Tape
The previous section copied the ORDERS file to tape. This section restores one of
the items from tape. If you removed the tape at the end of the previous section of
this tutorial, you should replace the tape cartridge in the tape drive.
Enter T-ONLINE to attach the tape drive and rewind the tape. The system positions
the tape at the beginning of the tape, which is also the beginning of the ORDERS
file.
Using Magnetic Tape
10-7
You use T-LOAD to load a file from tape. However, it does not overwrite an
existing item on file. To demonstrate T-LOAD, assume you want to delete a single
item from the file, and then restore it from tape. The following command deletes
one of the items from the ORDERS file on disk.
>DELETE ORDERS 10121
‘10121’ Deleted
T-LOAD has the following syntax:
T-LOAD [DICT] filename [item-list] [selection] [(options)]
DICT
specifies the file dictionary.
filename
name of the file.
item-list
list of individual item-IDs. Enclose each item ID in single
quotes. If you do not specify a list of item IDs, the system
loads all items in the file.
selection
specifies one or more conditions that an item must meet
before the system restores it. For a complete description of
selection expression syntax, refer to LIST in the UniVision
Command Reference Guide.
options
include one or more single character codes that specify the
report format and direct or modify output. You must enclose
them in parentheses, enter them in any order, and need not
separate them with spaces or delimiters such as commas.
I
suppress the listing of the items being loaded.
O
allows you to overwrite items that exist in the file.
The following example, restores item ‘10121’ from tape and places it in the
ORDERS file.
>T-LOAD ORDERS ‘10121’
BLOCK SIZE: 16896
1
10121
1 Item(s) loaded
It is important to realise that filename specifies where you want to copy the items;
it does not identify the file on tape. The position of the tape determines the tape
file. Thus, T-LOAD searches for the specified data item in the current file on tape.
if, for instance, you specify the CUSTOMERS file, the system copies the item
‘10121’ from tape to the CUSTOMERS file.
10-8
When you finish restoration, the system position the tape at an EOF mark
following the file. To read from the same file on tape, you must reposition the tape
at the beginning of the file. When using a cartridge tape, you must position the
tape at the beginning and advance it forward to the particular position of the file.
Because there is only one file on this tape, you need to rewind the tape to the
beginning. Use T-REW to rewind the tape.
>T-REW
BLOCK SIZE: 16896
In addition, T-REW reports the current block size. If you are near the system itself,
you should be able to hear the system rewinding the tape.
As was mentioned earlier, T-LOAD does not overwrite an item if it already exists
on file. Issuing the same command produces the following result:
>T-LOAD ORDERS ‘10121’
BLOCK SIZE: 16896
‘10121’ already exists
0 Item(s) loaded
The system does not write the item from tape. If you want the item from tape to
overwrite the item on file, use the parenthetical option O with T-LOAD.
You can use LIST and SORT to view the contents of items on tape. The TAPE
modifier extracts items from the current file on tape as though it were a data file
on disk. For example, to position the tape to the beginning of the file.
>T-REW
BLOCK SIZE: 16896
Use LIST to list the data from two attributes of a single item.
>LIST ORDERS ‘10121’ TOTAL.AMT DATE TAPE
PAGE 1
15:09:23
ORDERS...
Amount...
Date of Order
10121
$68.94
15/11/96
22 NOV 1996
End of list
! Note:
Using Magnetic Tape
The filename ORDERS as specified in the statement
identifies only the dictionary used to issue the report. It
does not identify the file on tape.
10-9
Appending Data to Tape
The system writes an End-Of-Data mark at the end of the last file on tape.
To write another file to the same tape as used to write the ORDERS file, you must
position the tape at the EOD mark. T-EOD moves the tape to the EOD mark.
>T-EOD
BLOCK SIZE: 16896
[92] End of recorded data - 1 FILE(S)
Once the system has positioned the tape at the EOD, it is possible to dump another
file to tape. The following example, dumps the CUSTOMERS file.
>T-DUMP CUSTOMERS
BLOCK SIZE: 16896
1 AEDWA51BLA
2 SPIRS112AE
3 AJOHN760JE
4 HJENK1222M
5 AMEAD251BL
6 JBROW129B0
7 BLEAR34TRE
8 JPEER89RIA
9 HJOHN3550T
10 JBOHA126TR
11 JBUCK26STO
12 HHIGG5425T
13 DEDGE338BR
14 AORLA55VEN
15 MASHX912AE
16 RPIER123WE
17 BLAMP344TR
18 JMASO226RO
18 Items dumped
Now there are two files in sequence on the tape.
Positioning the Tape
This section examines a few commands used to position the tape and determine its
contents. Some tape devices, such as quarter-inch, 8mm, and 4mm DAT tape
drives cannot backup one tape record. Half-inch tape and diskettes can backup one
tape record. When using a device that cannot be backed-up you must rewind the
tape and position the tape by moving to the correct position.
10-10
When you write a file to tape, the system writes an EOF mark after the end of the
last tape record used by the file. To locate a particular file on tape, you position
the tape just after the EOF preceding the specified file. Figure 10-1 shows the
layout of data on a cartridge tape. The system stores the contents of a file in
physical tape records. These records are of fixed length, specified as the block size
when you attach the tape. If the contents of a file do not fill up the tape record, the
system pads the record to fill it. If the contents of the file do not fit in a single tape
record, the file spans multiple tape records.
Each file written to tape has a label. The information on this label can vary, but it
should provide the time and date of tape creation and the name of the file. The
tape label can be 80 or 512 characters long, the device determines the label size.
For example, half-inch tapes are 80 bytes long, 8mm and 4mm DAT tapes are 512
bytes long. Quarter inch tapes can be 80 or 512 bytes long. On quarter-inch drives
you can set the label size by issuing a T-FORMAT with the L (long) or S (short)
option.
LABEL
Size of the physicalrecord is
a fixed length, set as the
block size
Tape
Record
File1 fits in a single tape
record
Tape
Record
EOF
EOF
BOD
LABEL
Tape
Record
File2 spans over two
physical tape records
Figure 10-1.
Layout of data on cartridge tape
Using Magnetic Tape
10-11
The following example, repositions the tape at the beginning and uses T-RDLBL
to examine the label of the first file on tape.
>T-REW
BLOCK SIZE: 16896
>T-RDLBL
BLOCK SIZE: 16896
L 4200
14:43:11 25 NOV 1995 ORDERS
~1
>
As you can see, this label identifies the ORDERS file. After executing T-RDLBL,
the system positions the tape after the label. To be able to read the label of the
next file on tape, you must advance the tape to the next EOF mark.
There are two ways to advance the tape. T-SPACE counts EOF marks to advance
the tape past a specified number of files. T-FWD moves forward to the next EOF.
T-FWD n moves forward n records or to EOF if there are less than n records in the
file. Because the first file consists of only a single block of data, and the system
positions the tape before the first block, you can use T-FWD to move to the next
EOF mark.
>T-FWD
BLOCK SIZE: 16896
[94][EOF]End Of File
>T-RDLBL
BLOCK SIZE: 16896
L 4200
14:43:11 25 NOV 1995 ORDERS
~1
>
T-RDLBL displays the label that identifies the CUSTOMERS file.
T-FWD 1 moves ahead to the next tape record. If a file spans several tape records,
you can advance the tape a record at a time or for a specified number of records
using T-FWD. If you specify a block size smaller than the default, then it is more
likely that the system stores a file on tape in multiple tape records. If this is the
case, it might be easier to position the tape using T-SPACE, which is the same as a
sequence of T-FWD commands.
T-SPACE is a Proc the executes T-RDLBL and T-FWD to move ahead by a
specified number of files. The following example, rewinds the tape, and uses Tnd
SPACE to position the tape at the beginning of the 2 file.
10-12
>T-REW
BLOCK SIZE: 16896
>T-SPACE 1
BLOCK SIZE: 16896
BLOCK SIZE: 16896
L 4200
14:43:11 25 NOV 1995 ORDERS
~1
>
T-SPACE displays the label of the file that it passes over. The system now
positions the tape at the beginning of the CUSTOMERS file and you could use TLOAD to restore items from the tape file.
Before continuing, you should detach the tape drive from the process and remove
the tape cartridge or reel from the drive. Use T-UNLOAD to rewind and unload the
tape in a ½-inch tape drive.
Tape Command Summary
There are two groups of magnetic tape verbs: utility verbs and production verbs.
Utility verbs set up the tape drive or position the tape for various operations.
Production verbs allow you to read and write formatted tapes.
The following is a list of tape commands, arranged alphabetically.
FORMAT
Formats a floppy disk for use in UniVision.
T-ATT
Attaches a logical tape unit to the user’s process.
T-DET
Detaches a tape unit from the user’s process.
T-DUMP
Copies items to magnetic tape.
T-EOD
Advances a tape to the end of the data.
T-ERASE
Erases selected tape drives
T-FORMAT
Sets the tape drive format.
T-FWD
Advances the tape forward.
T-LOAD
Restores items from tape to disk.
T-ONLINE
Puts the tape drive on-line and rewinds the tape.
T-RDLBL
Reads, displays and stores tape labels.
T-READ
Displays the contents of a tape.
T-RET
Retensions the tape media.
T-REW
Rewinds a tape.
T-SELECT
Selects and attaches logical tape units to a process.
Using Magnetic Tape
10-13
T-SPACE
Spaces a tape forward.
T-STATUS
Lists the current tape device assignments.
T-UNLOAD
Rewinds and unloads a tape media under software control.
T-WEOF
Writes an End-OF-File mark on tape.
T-WHAT
Displays the type of tape drive currently selected.
T-WTLBL
Writes and stores labels.
In addition, to these commands there is a TAPE modifier, which reads items from
the current file on tape.
Overview of Utility Verbs
The utility verbs, T-ATT, T-ONLINE, and T-SELECT, allow a process to gain
exclusive control of a tape drive. T-DET relinquishes control of the tape drive on
completion of processing. T-FORMAT establishes the QIC format of the tape, such
as QIC150, QIC525, etc. In addition, T-FORMAT can set tape label length (80 or
512 bytes) and high or low density, such as 1600 BPI, 320 BPI, 6250 BPI, etc. TSTATUS displays the status of tape drives.
You use the utility verbs T-FWD, T-EOD, T-REW, and the T-SPACE Proc to
position the tape. T-WEOF writes an EOF mark on tape. T-RET retensions tapes.
T-ERASE erases selected tape drives. Two utility verbs, T-READ and T-RDLBL,
are available to inspect tapes and can be helpful if you encounter any difficulties
when using tape as a storage or transport medium.
Overview of Production Verbs
The production verbs fall into four categories:
•
Performing an account-save or file-save and restoration.
•
Reading and writing files using VISION verbs.
•
Reading and writing Spooler print files.
•
Reading and writing tape records using UniVision BASIC.
Performing an Account-Save or File-Save and Restore
The basis for commands used to save and restore the system is the result of SAVE.
ACCOUNT-SAVE and FILE-SAVE invoke SAVE with a specific group of SAVE
options.
You can retrieve data from a SAVE tape using any of the following methods.
10-14
•
:FILELOAD
•
ACCOUNT-RESTORE
•
ADD-ACCOUNTS
•
SEL-RESTORE
The UniVision System Administration Guide covers the commands used for
backing up and restoring the system.
Reading and Writing Files using VISION Verbs
T-DUMP, S-DUMP and T-LOAD write data to and read data from tape. T-DUMP
and S-DUMP save data from one file at a time, and is the recommended method of
creating tapes for data transfer between the different types of PICK-based
systems. T-DUMP and S-DUMP allow you to use selection expression to identify
the items dumped to tape. In addition, it accepts item-lists and processes an active
select-list. T-LOAD retrieves data written by T-DUMP or S-DUMP and loads it into
a specified file. In addition, it accepts selection expressions to identify a set of
items you want to load.
T-DUMP and SAVE format the data on the tape in a different manner, thus the data
is not interchangeable between these tape formats.
Reading and Writing Spooler Print Files
You can spool print files to tape by assigning the tape drive as the destination for
subsequent print jobs: see SP-ASSIGN and SP-EDIT. You can read print files
from tape and output them to the printer using SP-TAPEOUT, or you can make
them into hold files with the HS option of SP-ASSIGN. You can use print files to
make tapes that are readable by non UniVision machines. You can use SPTAPEOUT to read files on tape that use carriage returns or linefeeds as record
delimiters. Refer to the Section entitled The Spooler for more information on
spooling files to tape, in addition see the section at the end of this Section on
transferring data to non UniVision systems.
Reading and Writing Print Records using UniVision BASIC
READT and WRITET are UniVision BASIC statements used to read and write
from tapes. These statements assume full control of all blocking and deblocking of
tape data records.
Each time you issue WRITET, the system writes a new tape block. WRITET
specifies that the system places a string in the next tape block. If the string does
not fill up the tape block, the system pads the unused portion with blanks. There
are two conditions that produce error messages.
•
If the string is null.
Using Magnetic Tape
10-15
•
If the length of the string exceeds the size of the tape block.
In the latter case, the system truncates the string to fit in the tape block.
A data record written with WRITET cannot span two blocks. Therefore it is
efficient to write fixed-length data records and to set the block size equal to the
size of the data record or to a multiple of it.
Understanding Tape Layout
The layout of data on tape is different for ½-inch and ¼-inch tape drives. The
main difference is that the ½-inch tape uses an Inter-Record Gap (IRG), a length
of tape used to demarcate the sections on tape. Figure 10-2 shows the layout of ½inch tape. On ½-inch tape, two consecutive EOF (End-Of-File) marks indicate the
EOD (End-Of-Data). On the ¼-inch tape, the beginning of a section of blank tape
indicates the EOD.
end of data
E
O
F
I
R
G
LABEL
I
R
G
DATA
I
R
G
E
O
F
E
O
F
Figure 10-2.
Tape layout for ½-inch tape
The system writes data to fixed-length blocks or physical tape records. Files
consist of variable-length items that are logical data records. Because the system
stores data records as a continuous string, multiple file items can fit in a single
block and the system allows individual items to span over multiple blocks.
Thus there is no necessary correlation between block size and data record size.
The system pads any unused portion of a tape record at the end. The pad character
is an X’FB’ character if T-DUMP and SAVE generate the tape. It is a null (X’00’)
character if the tape record contains a print file. The pad character is a blank when
UniVision BASIC generates the tape.
UniVision BASIC tape statements do not write labels. You can use T-WTLBL to
write a label to tape. In addition, the programmer is responsible for writing the
EOF. mark.
10-16
Tape Label Format
A tape label consists of seven elements, as shown in Figure 10-3. A label is 80 or
512 bytes in length. Only the first 80 bytes are significant in a 512 byte label, the
system pads other bytes with the null character (X’00’). T-DUMP and S-DUMP
create it.
system time
source file
label
indicator
L
reel number
01F4
16:12:27 06 MAR 1997
FILENAME
block size
TEXT…..~1
header text
system date
Figure 10-3.
A sample tape label
The label contains the source file name as specified in T-DUMP. In addition, it
contains any user-supplied text provided using the HEADER, or HEADING
modifier. The system only stores the first 47 characters in the heading on tape. For
instance, the following T-DUMP uses the HEADER modifier to add text to the
label after the filename:
>T-DUMP CUSTOMER HEADER “BEFORE REMOVING DUPLICATES”
You can read the resulting label with T-RDLBL:
>T-RDLBL
BLOCK SIZE: 16896
L 0800 11:31:36 26 NOV 1996 CUSTOMERS BEFORE REMOVING DUPLICATES ~1
If necessary the system truncates the header string from the right to fit into the
label block. If the Spooler generates the tape output, the file name is the account
name. UniVision BASIC does not write a label.
Using Magnetic Tape
10-17
Block Size
It is possible to change tape block size in two ways. You can specify a block size
with T-ATT, or you can read it from a tape label using the UniVision tape-reading
commands T-RDLBL and T-READ. These commands change the block size to
match the block size used when the system dumped the data to tape.
The system tests specified block sizes against a range of values allowed for the
system configuration. If the block size specified with T-ATT falls outside the valid
range for that configuration, the system adjusts the block size.
½-inch Tape Block Sizes
On the ½-inch reel-to-reel tape drives, the recommended minimum record size is
80 bytes for the generation of a tape of card images for transfer to a machine that
needs such a tape. The recommended record length is 4000 bytes and the
maximum block size is 32256 bytes.
The presence of the Inter-Record Gap (IRG) places an upper limit on the number
of blocks on a tape of given length. The block size used affects the storage
capacity of the tape. Since the tape drive starts and stops for each record,
increasing block size decreases the number of blocks on the tape as well as the
number of IRGs. The optimum block size decreases wear and tear on the tape
drive, decreases processing time and increases system throughput.
¼-inch Tape Block Sizes
On a ¼-inch cartridge tape drive, the block size must be a multiple of 512. The
system rounds block sizes that are not multiples of 512 down. Any block size
specification lower than 512 bytes defaults to 512. The maximum block size is
32256 bytes.
8mm and 4mm DAT Tape Block Sizes
On 8mm and 4mm DAT tape drive, the record length can be any number up to
33256 bytes, although the recommended value is the default of 4096 bytes. For
best results, the block size should be a multiple of 1024.
Diskettes and CD-ROM Device Tape Block Size
When using diskettes, the block size supported is 500 bytes. If you specify any
block size less than or greater than 500, the system ignores it and uses 500 bytes.
10-18
Selecting the Tape Drive
If there is only one tape drive on the system, you can skip this section since the
system would set up that tape drive as the default tape unit. This section is about
how to select a specific tape drive.
Setting Tape Drive Assignments
The system assigns numbers, known as logical tape unit numbers, to tape drives,
like printers, you add them to the system. You assign a logical tape unit number to
each physical tape drive using SET-TAPE. You usually make these assignments
when you cold-start the system, (if you have specified them in the USERSTARTUP Proc). In addition, you can override them to allow a different physical
tape drive to be a particular logical tape unit.
The UniVision Command Reference Guide describes SET-TAPE.
Listing Current Tape Device Assignments
You can determine the current tape assignments by examining the report produced
by T-STATUS. T-STATUS lists all assigned logical tape units, their assigned tape
devices, the attached processes (if any), and the tape format specifications.
T-STATUS[(P)]
The only option available for T-STATUS is the P option, which sends the report to
the printer.
T-STATUS produces a report such as the following:
>T-STATUS
LTU DRIVE ATT FORMAT
0
1
Q0
F0
DEVICE DESCRIPTION
UNIX DEVICE NAME
021 LONG LABEL
WANGTEK 5525ES SCSI /dev/rmt/c0t3d0s0n
HIGH DENSITY 3.5 inch 1.44 Mbyte /dev/rdsk/f03ht
This report contains the following information:
LTU
logical tape unit.
DRIVE
type and number of the tape drive assigned to the tape unit.
Type can be:
Using Magnetic Tape
F
floppy disk drive.
E
8mm tape drive.
H
½-inch tape drive.
Q
¼-inch tape drive.
10-19
D
4mm tape drive.
C
CDROM drive.
ATT
number of the process attached to the tape unit. If you have
not attached a tape unit, this field is empty.
FORMAT
tape format as set by T-FORMAT.
The T-STATUS report does not list any tape units not assigned with SET-TAPE.
Selecting a Tape Drive for an Account
Whenever a user logs on to the system, it selects tape unit 0 automatically by
default. However, the system does not attach it to the user’s process. The user can
select and attach another tape unit, or a set of tape units, by executing T-SELECT.
These tape units remain selected until the user logs off or selects another tape unit.
They remain attached until the user logs off or detaches them with T-DET. TSELECT selects one or more tape units and attaches them to your current process.
You can use T-WHAT to report the current selection for your account.
>T-WHAT
[6007] 1/4 Inch cartridge unit
LONG LABEL
This example reports that you have selected logical tape unit 0, the default, for this
account and that it is assigned to a ¼-inch tape drive.
Use the following syntax to select a single tape drive for an account:
T-SELECT [tapeunit1]
where tapeunit1 is the number of logical tape unit.
T-SELECT checks the DEVICE-NAMES files to check for a valid device name.
You can only select a tape unit assigned to a physical tape device with T-SELECT.
If you have not assigned the tape unit, the system displays the following message.
[6008] Tape unit not assigned
If you have another process attached to the tape unit, the system displays the
following message:
DEVICE d ATTACHED TO USER n
and the system selects the tape unit but does not attach it to the user’s process.
The U option unconditionally detaches the tape unit from another process and
attaches it to the user’s process.
10-20
! Note:
Do not detach a tape drive that is currently in use, and
never hand-code a T-DET into a program.
The following example shows how to select and attach tape unit 1.
>T-SELECT 1
[6037] Floppy device attached
>T-STATUS
LTU DRIVE ATT FORMAT
0
1
Q0
F0
DEVICE DESCRIPTION
UNIX DEVICE NAME
021 LONG LABEL
WANGTEK 5525ES SCSI /dev/rmt/c0t3d0s0n
HIGH DENSITY 3.5 inch 1.44 Mbyte /dev/rdsk/f03ht
Selecting Multiple Tape Drives
You can use T-SELECT to chain two or more tape drives to a single process. This
allows you to perform multi-reel operations without operator intervention. You
must assign each of the tape units to tape drives of the same type and using the
same format.
Use the following syntax for T-SELECT to select a chain of tape drives:
T-SELECT [ tapeunit1[-tapeunit2]|({P|S})] [(U)]
where tapeunit1 is the number of the logical tape unit from 0 to 11, tapeunit2 is
the number of one or more additional tape units chained to tapeunit1, P is tapeunit 0, the primary unit and S is tape-unit 1, the secondary unit. Specify each tape
unit, separated by hyphens, in the order in which you want them chained. If the
system cannot attach one of the tape units in a chained set to the user’s process for
any reason, the system does not attach any of the specified tape units, although tit
does select them.
The following example selects and attaches tape units 0, 2, 3 and 1, in that order,
as a chained set.
>T-SELECT 0-2-3-1
Tape operations using this set proceeds from tape unit 0 to tape unit 2, then to tape
nd
unit 3 and finish on tape unit 1. You can mount a 2 set of reels and operations
return from tape unit 1 to tape unit 0. Tape operations proceed, going round the
chain again in the same order.
It is not possible to chain unlike tape devices. If you specify unlike tape devices
for example, a quarter-inch cartridge and diskette the system displays the
following warning and does not select the devices.
>T-SELECT 0-1
DEVICES 0 AND 1 ARE DIFFERENT TYPES OF DEVICE
Using Magnetic Tape
10-21
Specifying Tape Drive Format
T-FORMAT rewinds the tape and sets the tape format for the tape drive.
To display the current tape format set, enter T-FORMAT with the ? option.
If you enter an invalid selection at either prompt, the system displays the
following message:
‘X’ IS NOT A VALID FORMAT FOR THIS DEVICE
Attaching a Tape Device
T-ATT attaches the currently selected tape unit to your process, giving you
exclusive control of the assigned tape drive. A number of tape verbs automatically
attach the process to the tape drive. Therefore you do not need to use T-ATT to
attach the tape drive unless you want to change the block size. The syntax is:
T-ATT [block]
block
block size of the tape record, in bytes. The maximum is
32256 bytes.
The system defaults are:
¼-inch tape drives
½-inch tape drives
8mm tape drives
Floppy disk drives
4mm tape drives
CD-ROM
16896 bytes
16000 bytes
16384 bytes
500 bytes
4096 bytes
512 bytes
Using T-RDLBL with a mounted labelled tape sets the block size to the tape record
length specified in the tape label.
When you have attached the tape unit to the process successfully, the system
displays the following message:
BLOCK SIZE: xxxx
where xxxx is the block size.
If you have attached the selected tape unit to another process, the system displays
DEVICE d ATTACHED TO USER x
where x is the process number attached to the tape unit.
10-22
The system detaches the tape unit from the process automatically when log off
takes place. You can detach it at any time by issuing T-DET.
Detaching a Tape Unit
T-DET detaches the attached tape unit from the process. Detaching the tape unit
releases it from the exclusive control of the process and makes is available to
other users.
The tape unit remains selected, however. T-DET deletes all multiple tape units
attached to the process.
>T-DET
>
The system does not display a message if the detachment is successful.
The U option of T-DET, which requires SYS2 privilege, detaches the currently
selected tape unit from any process it is possible to attach to. The U option affects
only the currently selected tape unit. If the selected tape unit is currently attached
to another process, using T-DET with the U option detaches the tape unit from the
other process and makes it available again. If the selected tape unit is one of a
chained set, the system detaches the entire set.
! Note:
It is not recommended practice to use the U option to
detach tape units, since other processes might be using
those tape drives.
Attaching a Cartridge Tape Unit
T-ONLINE resets the cartridge tape drive, checks that you have inserted a tape
cartridge, and rewinds the tape.
Before you use T-ONLINE, insert a tape cartridge in the ¼-inch tape drive. If you
have selected the tape unit assigned to it, T-ONLINE checks for attachment,
determines that you have inserted a tape into it, and rewinds the tape.
The following example resets the ¼-inch tape drive:
>T-ONLINE
BLOCK SIZE: 16896
[6004] Tape on line
Since T-ONLINE can attach the tape drive, you do not need to use T-ATT. A
standard practice is to enter T-ATT first. A program can test if the T-ATT fails and
take alternative action. If it fails using T-ONLINE, the system prompts the user to
continue of quit.
Using Magnetic Tape
10-23
If you have not inserted a tape, T-ONLINE attaches the tape unit, if selected, and
displays the following message:
>T-ONLINE
BLOCK SIZE: 16896
DEVICE NOT READY
CONTINUE/QUIT (C/Q)?
To continue, insert a tape cartridge in the drive, and enter C at the prompt. To quit,
enter Q.
Positioning the Tape
This section covers commands used to position the tape. There are commands for
rewinding the tape and for advancing the tape to specific tape blocks or to an EndOf-File mark.
Rewinding the Tape
T-REW rewinds a tape to the load point (BOT).
T-REW
When system has rewound the tape, the system returns to the UCL prompt. If the
tape is already at beginning of tape, the system takes no action.
The following example rewinds the attached tape:
>T-REW
BLOCK SIZE: 16896
Forwarding the Tape
T-FWD advances a specified number of tape records or to the End-Of-File mark.
T-FWD [record]
record
number of records you want to advance. The maximum is
32767.
If you encounter an End-Of-File mark before passing the specified number of
records, or if you do not specify record, the system position the tape after the
End-Of-File mark.
10-24
The following example moves the attached tape forward one record:
>T-FWD 1
BLOCK SIZE: 16896
If you have not specified an argument, T-FWD advances to the next EOF.
Reading Tape Labels
T-RDLBL reads a tape label, whether it is at the beginning of a tape or at the
beginning of a file that is after an End-OF-File mark. Using T-RDLBL with a
mounted labelled tape sets the block size to the tape record length specified in the
tape label.
T-RDLBL
T-RDLBL reads the tape label and displays the reel number, block size, time, and
date when the system wrote the tape, and a header text on the screen.
If you use T-RDLBL, on a tape that is one of a multi-reel set of tapes, the system
includes the reel number with the tape label. At the end of the tape, the system
prompts you to load the next reel in sequence.
! Note:
T-RDLBL reads tape labels created by T-DUMP or SAVE
operations. Tape labels created on non-UniVision
systems are incompatible and most of the time you
cannot determine the block size. In order to use the tape
you must know the block size and issue the proper
commands to avoid or skip the tape label.
Moving to a Specified File
T-SPACE spaces a tape forward over a specified number of files. T-SPACE
executes T-RDLBL and T-FWD as many times as number specifies. The syntax is:
T-SPACE number
where number is the number of files to space over. If you do not enter number in
the command line, the system prompts you to enter it.
The following example moves the tape forward one file:
>T-SPACE 1
BLOCK SIZE: 16896
BLOCK SIZE: 16896
L 4200 09:20:11 28 NOV 1996 CUSTOMERS
~1
>
Using Magnetic Tape
10-25
Advancing to End-Of-Data
T-EOD moves the tape forward to the end of the recorded data. At the EOD mark,
you can append new data to the tape.
The following example advances the attached tape to the end of the recorded data:
>T-EOD
BLOCK SIZE: 16896
[6000] End of recorded data
Writing an End-Of-File Mark
T-WEOF writes an End-Of-File mark on the tape at the current position.
T-WEOF
If the tape’s write protection is on or if no write ring is present, the system
displays one of the following messages:
WRITE PROTECTED
or
DEVICE NOT READY
Remove the write protection or install a write ring, and enter C to continue, or
enter Q to quit.
Unloading a Tape
T-UNLOAD rewinds the tape to the load point (BOT). If supported the drive ejects
the tape.
T-UNLOAD
When you have unloaded the tape, the tape unit is no longer on line. This means
that no other process can read or write to the tape. The system returns to the UCL
prompt. If you have finished using the tape device, you should detach it using TDET.
10-26
Erasing Selected Tape Drives
T-ERASE erases selected tape drives and rewinds to the beginning of the tape
(BOT).
T-ERASE
! Note:
T-ERASE erases all data on the tape media.
Retensioning Tape Media
T-RET retensions the tape media. A tape retension fast-forwards to the end of tape
and rewinds. This action on the tape media allows the tape drive to correct any
bumps in the actual media.
T-RET
Other Tape Verbs
It is possible to use three other verbs with tapes. T-DUMP and S-DUMP create a
tape containing all or selected items from a file. T-LOAD reads all or selected
items from a tape and loads them into a file or file dictionary.
Dumping a File to Tape
T-DUMP transfers a copy of all or selected file items to magnetic tape. In addition,
T-DUMP creates a tape label and writes an End-Of-File mark on the tape after the
completion of the transfer. You can find the syntax of T-DUMP in the UniVision
Command Reference Guide. S-DUMP is a version of T-DUMP that accepts a sort
expression.
The following modifiers operate in a special way relative to T-DUMP and SDUMP.
HEADER ‘text’
Specify heading text used in the tape label.
HEADING ‘text’
Same as HEADER.
HDR-SUPP
Suppresses the creation of a tape label.
ID-SUPP
Suppresses listing of item IDs during the copy-to-tape
operation.
If the tape’s write protection is on or if no write ring is present, the system
displays one of the following messages:
WRITE PROTECTED
Using Magnetic Tape
10-27
or
DEVICE NOT READY
Remove the write protection or install a write ring, and enter C to continue, or
enter Q to quit.
The following example writes all items from the ORDERS file whose date is
before December 12, 1987 to magnetic tape. The tape label includes an addition to
the standard text that reads ‘OLD ORDERS’.
>T-DUMP ORDERS WITH DATE LT “12/12/87” HEADING “OLD ORDERS”
1
10117
2
10232
3
10089
.
.
.
24 Items dumped
If you execute a T-DUMP, and the file is empty, that is, no items dumped, the
system writes an EOF mark to tape. This allows a Proc that executes multiple TDUMPs followed by as many T-LOADs to function properly.
Restoring Items from Tape
T-LOAD restores file items previously copied to tape with T-DUMP or S-DUMP.
You can only copy these file items to an existing file. You can find a description
of T-LOAD in the UniVision Command Reference Guide.
When the restore operation is complete, the system positions the tape at the EndOF-File (EOF) mark.
The following example restores all item from the tape file to the ORDERS file
from magnetic tape. The I option suppresses the listing of item IDs:
>T-LOAD ORDERS (I)
24 Items loaded
Including Data from Tape in Reports
You can use the TAPE modifier with any VISION modifier to retrieve data from
tape and display it in reports. The you must attach the tape unit prior to using the
TAPE modifier. By adding the TAPE keyword to a statement, the report uses the
items from the file on tape, even if there is a data file on disk with the same name
and containing the same items.
10-28
The following example reads the items from tape, using the ORDERS dictionary,
and displays a report on the screen.
>LIST ORDERS CUST.ID DATE TOTAL.AMT TAPE
Examining the Contents of a Tape
T-READ reads a tape record and displays its contents on the screen or sends it to
the printer. It does not restore the data or format it. It is somewhat the equivalent
of DUMP, which dumps a specified frame on the screen. T-READ dumps one or
more blocks from tape, and you can use it to examine the tape to locate a specific
file. The syntax is:
T-READ [n-m][(options)]
where n is the number of tape records to read and display relative to the current
record. If you do not specify n, the system displays all records up to the next EOF.
n-m specifies a range of records.
T-READ options can be any of the following:
A
converts from EBCDIC
alphanumeric segments.
to
ASCII,
then
displays
P
sends the display to the printer.
S
prevents the tape cartridge from rewinding to the tape label.
You can only use this option on a 1/4-inch tape drive.
X
displays tape contents in hexadecimal format as well as in
character format.
st
On ¼-inch tape drives, the 1 element T-READ displays is the tape label. If the
system has not positioned the tape at the label, T-READ rewinds the cartridge to
the beginning before it reads the tape.
Using Magnetic Tape
10-29
>T-READ (1
BLOCK SIZE: 512
L 0200 16:34:10 29 NOV 1996
DICT MD
~01
RECORD = 1
1
51
101
151
201
251
301
351
401
451
501
BLOCK-CONVERT^Q^BLOCK-CONVERT^^^^^^^L^10^[T-LOAD^P
T^35^73^[RTD^P^20A0^[DATA^CZ^[DTR^[^10A0^[LISTPEQS
^PÂB^[TAPETEST^PQ^SSÎTÎF A # DALE’S ORDERS GO
100^HTIME^P^D0^X^100 ONOT THE RIGHT TAPE^P^[IT^PQ
IT^D0^HTIME^P^[X-ON^P^510E^[T3^PQ^T (-5),”TWINKLE”
,(-6)^[B^PQ^HSORT ORDERS BY-EXP^S2Â^HBREAK-ON^B^D
0Â^HTOTAL AMOUNT^P^[HEADING^CL^[BLOCK-PRINT^P^500
A^41^[SS^PQ^SS^HLIST CUSTOMERSÂ2^D0^P^[“A10Â^10^
^^^^^^L^10^[LOCALSUB^PQ^HSORT CUSTOMERS BYÂ2^HNLNA
ME FNAMEÔDOUBLE SPACE?+ÎP^S3ÎF A = Y []20^P^X^
20 H DBL-SPC
>
The following example, uses T-FWD to advance four physical tape records. TREAD, entered with the S option, displays the block at that position.
>T-FWD 4
BLOCK SIZE: 512
>T-READ 1S
BLOCK SIZE: 512
RECORD = 1
1
51
101
151
201
251
301
351
401
451
505
REPORTÎPÎF A = YES GO 500ÎF A # YES X REPORT
NOT GENERATED^500 HSORT CUSTOMERS BY LNAME^H LNAM
E_[FNAME^P^TESTIP2^PQÔDO IT+ÎP2?ÎF A = N GO 99
9^HSORT CUSTOMERS^P^999 x I WONT THEN^[CUST-FIND^
PÊ6^^^BP^[DEBUG-OFF^P^1234^[FXSUB^PÊ6^^^BASICLIB
^[D^[^242^[SIZEÂ^9999^^^^^^MR0^R^10^[C-O^PQ^R.R M
D CUST.ORDER.LIST^P^[LBP^Q^LMUI^BP^^^^^^L^10^[V/CO
NVÂ^07^CONVERSIONS^^^^^^L^30^1^[LIST-LABEL^PA^35^
4D^7D^[BUILD-LOCK-XREF^PÊ6^^^BASICLIB^[L/UPDÂ^06
^^^^^^^L^5^[ADDD^PA^40A0^[LISTPTR^PÂE^[SORT-ITEM^
PA^35^4E^508
>
This block is somewhere in the middle of a file. The system does not display a
label. Without the S option, the system would have rewound the tape to the
beginning and the output would be the same as the previous example.
Transferring Data to and from Other Systems
This section looks at specific issues involved when using tape media to transfer
data between computer systems.
10-30
Transferring Data between Pick-like Systems
The most reliable method of transferring data between a UniVision and a Pick-like
system is using T-DUMP to create the tape and T-LOAD to restore it. As a rule, the
recommended tape block size is 512 bytes for tape compatibility. When loading a
tape onto UniVision, use T-READ to read the label and re-attach the tape using the
correct block size. In addition, it is a good idea to suppress the tape label when
making the tape, as tape labels vary between different versions of Pick or Picklike products.
Transferring Data to a Non-Pick-like System
To be able to transfer data on tape media to a non-Pick-like system, such as an
IBM mainframe, the two tape drives involved in the interchange must be
compatible. To know whether or not they are compatible involves examining the
technical specifications of both drives. Generally, you can transfer 1/2-inch tapes
between different types of machine. In brief, create a 9-track tape at either 1600 or
6400 bpi, (bits per inch), using the ASCII character set with high order bit off and
write fixed block records without labels.
Once you are able to determine the compatibility of physical protocols, you must
check the compatibility of character sets. If the data on the tape does not use the
ASCII character set, you must translate it. SP-TAPEOUT can translate EBCDIC to
ASCII, providing the source tape uses carriage returns and linefeeds as delimiters.
rd
If two drives are incompatible, you must use a 3 machine that supports a tape
drive, can read the source tape and create a compatible tape for the target machine.
Use of Print Files
Tapes created with T-LOAD and SAVE are formatted tapes that contain standard
delimiters for items, attributes, and values. Generally, a non UniVision machine
cannot read a formatted tape unless you have written special programs. In some
cases, you might use print files to transfer data between UniVision and nonUniVision machines.
Print files are a continuous string of data with lines delimited by carriage returns
(X’0D’) and linefeed (X’0A’) characters. You delimit pages with form-feed
(X’0C’) characters. If the page length parameter found in TERM is zero, VISION
does not paginate. The system pads the end of the print file with nulls.
Each line of a print file is of variable length, without padding of blocks on the
right. If you require fixed-length lines, you could print a meaningless character in
the far-right column of each line. .HILITE in Runoff can format text by placing a
specified character always in the same column; it includes spaces before the
character and a carriage return and linefeed.
Using Magnetic Tape
10-31
It might be possible to truncate individual data values to fixed-length fields that
you have concatenated to form a single fixed length record. You must reserve the
final two character for the CR/LF.
Another strategy is to use the F correlative to construct a fixed-length data record.
For instance, the following correlative:
F;2(ML####)
formats the second attribute as a 4-character string.
Use SELECT or SSELECT, specifying an output attribute, to produce a select-list
containing the desired attributes of the data items as though they were keys. Save
the select-list and read it into a UniVision BASIC program using READNEXT to
obtain each data record from the list. The program can pad them as you desire.
This approach uses less programming and computer time. COPY-LIST is available
if you want a hard copy of the transmitted data.
To read a non-UniVision tape that is in print file format, use SP-TAPEOUT. The
following command uses the A option to convert files from EBCDIC to ASCII:
>SP-TAPEOUT A
Use SP-EDIT to move the print file into items, in Runoff format, in a data file.
If the print file format is not acceptable, you must use a UniVision BASIC
program. In addition, UniVision BASIC is the best choice when you require
matching alternate data patterns.
Block Size
If the foreign tape label has the same block size as the data following it, the
system reads the label as data. Often labels are shorter than data and some
machines might produce two or three labels.
To read the data, use T-READ to read the label or T-FWD to skip past the label.
To use T-READ, the block size of the reading process must match the size of the
label. If it is not, the system displays the number of bytes specified by T-ATT on
the screen and the tape advances to the inter-record gap on 1/2-inch drives.
It is possible to find the size of the tape record by using T-ATT and T-READ
repeatedly. If the attached size is larger than the record size the system retries the
tape repeatedly. If the attached size is less than the record size, the system loses
the trailing bytes.
If you want to inspect the data, use T-READ. If the data is in EBCDIC, you can
translate it into hexadecimal using the X option.
10-32
Troubleshooting
The system detects many tape problems as parity errors, which can occur for a
number of reasons. Perhaps the most common cause of parity errors is using the
wrong block size when copying to and from tape. In addition, dirty tape heads can
cause parity errors. The tape itself might be bad, for instance, dirty heads might
have corrupted the data at the time the system wrote it to tape.
Another problem is that the following EOD message appears unexpectedly:
[6000] END OF RECORDED DATA
If you know that the system has not positioned the tape at the end of tape. Perhaps
you have specified the wrong tape format. Quarter-inch tapes use different formats
such as QIC60, QIC150, QIC525, etc. When you have set the tape drive to a
different QIC format from the format on the media the message above might
appear. use T-STATUS to check what the current tape format setting is, and use TFORMAT to specify the correct tape format.
A common problem is not using the proper command to read a tape. Make sure
you know what command you use to make the tape then use the appropriate
command to restore it. Obviously, physically labelling tapes is a key part of
ensuring that you can restore data from tape.
Using Magnetic Tape
10-33
Section 11
DATA COMMUNICATIONS
This section discusses how to communicate with other computer systems, via
RS232 communications. It covers the low level support for RS232 data
communications provided in the UniVision environment. It explains how to
establish the connection between two machines, and how to use that connection to
initiate a remote RS232 logon session on the other system.
In addition, UniVision supports a number of communications software products
that offer a higher level of integration for performing specific tasks between
systems such as:
WinLink
WinLink links your Microsoft Windows applications directly
to the UniVision Database. WinLink allows you to
incorporate the Windows interface into your applications
allowing UniVision users to support a true Client/Server
environment.
UniComms
UniComms is a set of utilities that allows a user to transfer
data between UniVision systems using industry-standard
protocols via serial RS232 cabling and modems.
WinLink Users Guide or UniVision UniComms Users Guide give details of the
above products.
Overview
It is possible to connect UniVision to another computer across a direct serial cable
or via a modem. This connection uses one of UniVision's serial ports.
CONVERSE allows a user to access a communications line for two-way
communications. In order to use the line via CONVERSE, you must unlink the
line serving that communications port from a process. You attach the available
line to the user's process and CONVERSE passes input from the user process to
the attached line. In addition, it directs output from that line back to the user
process.
Thus, if line 5 is an available line connected to a modem, a user at a terminal
attaches line 5 to the process to begin communicating with the modem.
Commands typed at the keyboard are 'passed-through' the process to the device
and interpreted by the device or passed to the remote system.
Data Communications
11-1
! Note:
Before using CONVERSE recommended practice is to
acquire the RS232 line for UniVision use using
Before
using
ACQUIRE-LINE.
CONVERSE
recommended practice is to acquire the RS232 line for
UniVision use using ACQUIRE-LINE.
Command Summary
ACQUIRE-LINE
Acquires UNIX line for subsequent use by UniVision.
CONVERSE
‘Connects’ an attached line and a linked line.
LINE-ATT
Attaches a line to a process, providing exclusive use of that
line.
LINE-DET
Detaches a line from a process.
LINE-PROTOCOL
Displays the line characteristics of specified lines.
LINK-LINE
Links a line to a process
LIST-ACQUIRED-LINE
Lists UNIX lines acquired for UniVision use.
LIST-LINE-CHARS
Lists protocol settings of processes and lines.
LINE-STATUS
Displays the status of a specified line or a range of lines.
PROCESS-STATUS
Displays the status of a specified process or a range of
processes.
PROTOCOL
Sets line transmission characteristics and protocols.
RELEASE-LINE
Releases a line acquired previously back to UNIX.
UNLINK-LINE
Unlinks and detaches a line from a process.
11-2
Making the Connection
When you have established a connection between UniVision and another
computer system, the connection between the two devices is across a serial cable.
There are two types of physical connection. A direct connection between
computers requires a serial cable running from a port on one system to a port on
the other system. A dial-up connection requires two modems, each connected to
one of the computers by a serial cable. The modems communicate with each other
across phone lines.
Setting Line Characteristics and Protocols
Two machines connected directly or by modem must have the same transmission
characteristics and communication protocols in order to communicate with each
other. You must specify the correct speed for data transmission (the baud rate), the
type of parity, and the number of significant data bits. In addition, you must
implement communications protocols such as DTR or X-ON/X-OFF, if used, on
both systems.
For a direct connection, the speed should probably be 9600. For a modem
connection, the baud rate depends on the speed of the modem and the speed of the
modems used by the systems performing communication. You must use the
lowest common denominator. 1200 and 2400 are the most common speeds,
although higher speed modems are becoming available. For performance and
throughput reliability there is a recommendation for a modem with error
correcting capabilities.
In addition, serial lines have the option of using a simple form of error checking
known as parity. Parity uses the setting of an additional bit to verify that what the
system sent out is the same as what it received.
There are five possible parity settings:
Odd
The sum of the parity bit plus the assorted data bits must
always add up to an odd number.
Even
The sum of the parity bit plus the assorted data bits must
always add up to an even number.
Marking
The parity bit is always 1.
Space
The parity bit is always 0.
None
There is no parity.
Data Communications
11-3
Even or odd parity are the only settings that provide any error protection. The
sending computer sets the parity bit to 0 or 1 depending on the value of the data
bits. The receiving computer checks to make sure that the parity came out as
expected - odd or even. If line noise (for example, on a telephone line) changes
one data bit (appears as 0 or 1 when the sending computer did not send it that
way), the parity is incorrect.
Various kinds of more complex error checking implemented in software or
hardware devices have superseded parity. Nonetheless, parity is a feature of serial
communications that you cannot overlook, since both sides must agree to use the
same parity settings or no communication occurs.
The basic data unit is a byte - 8 bits (or in the case of serial communications, 8
serial pulses). Two or three additional bits accompany a byte: a start bit, and either
one or two stop bits. When the system is not transmitting data, the signal on pin 2
(the carrier tone on a modem) is equivalent to a continuous stream of binary ones,
referred to as the MARKING state.
The start bit is a voltage equivalent to binary 0, often referred to as SPACE. After
receiving the start bit, both devices count the desired number of data bits and look
for the stop bit that is always binary 1.
In addition, it is possible to use only seven data bits, most commonly used in
communication links transmitting only text files, since ASCII codes (a standard in
the United States) use only seven of the eight bits of a byte; there is an extended
ASCII used internationally that uses a full 8 bits. A terminal set to 8 data bits with
no parity can often communicate with a line set for 7 data bits and any parity.
You use DTR and X-ON/X-OFF signals to establish a 'handshaking' protocol
between two systems. You observe these protocols to help control the flow of data
so that the transmitter does not send more data than the receiver can process at one
time.
DTR is a signal or voltage on a pin. A machine transmits data if DTR is present.
Some serial printers raise and lower DTR. X-ON flow control uses pins 2 or 3.
You set outward X-ON (X-OUT) if you want a printer or terminal to use a
<CTRL-S> to halt output and <CTRL-Q> to resume. When X-OUT is on, a
process never sees the <CTRL-S> and <CTRL-Q> because the line does not pass
these characters to the process. You only use X-IN, or inward X-ON, in intermachine communications. In addition, serial printer might set X-IN on but not XOUT because they are not expecting to get <CTRL-S> and <CTRL-Q>.
If you suspend output from the system by <CTRL-S> and X-OUT is 'OFF', the
line does not see the <CTRL-Q> to resume.
11-4
Using LIST-LINE-CHARS and PROTOCOL
Generally, when you install the system, all lines have the following default
settings:
BAUD
PARITY
BITS
DTR
X-IN
X-OUT
9600
NONE
8
OFF
ON
ON
Line/Process 0 might be different as it is usually the system console device.
If you use UniVision on a system where you configured the lines previously for
general O/S use, it uses those settings, that is, UniVision does not require any
special settings.
! Note:
If you configure the line for 8 bits with output Xon/Xoff
flow control, UniVision changes it, for the duration of
th
the UniVision session, to be full 8 bits, without 8 bit
stripping, and full input and output Xon/Xoff flow
control.
Use LIST-LINE-CHARS (or its simpler synonym LLC) to display all current line
characteristics. In addition, it is possible to list the line characteristics for a single
line or range of lines.
Use PROTOCOL to set or change line transmission characteristics. PROTOCOL
lets you set the baud rate, parity, number of significant bits, and lets you raise or
lower the DTR signal as well as monitor or ignore the DTR signal, set X-ON/XOFF protocol, and set other characteristics and protocols for all serial lines except
line 0. The system reserves line 0 for the pseudo system console, and so should
always be capable of communication with the system. Therefore, you cannot
change its baud rate, parity and number of data bits.
! Note:
Line/process 0 is the line that runs the initial building of
the UniVision parameter files.
The syntax is:
PROTOCOL line (options)
where line is the number of the line whose parameters you want to set, and options
are one or more of the following parameters in any order, separated by spaces or
commas:
baud
baud rate.
parity
parity
Data Communications
11-5
bits
number of significant data bits.
[-]D
enables or disables DTR (Data Terminal Ready) flow control
(NOT RECOMMENDED)
[-]XI
enables or disables inward X-ON/X-OFF flow control.
[-]XO
enables or disables outward X-ON/X-OFF flow control.
[-]W
enables or disables type-ahead buffer wrap. The system
accepts these options as input but UniVision does not action
them.
[-]B
enables or disables the bell signal on input buffer full
condition. The system accepts these options as input but
UniVision does not action them.
[-]C
enables or disables CTS flow control.
C={0|1}
forces the system's RTS output signal level low/high.
D={0|1}
forces the system's DTR output signal level low/high.
(C)
clears local input and output buffers.
(I)
clears local input buffers.
(O)
clears local output buffers.
(K)
kills line input and output.
BK=<xx>
sets an alternative break-key value in hex. This is useful for
network users.
XI=<xx><xx>
sets the XOFF/XON codes for inward flow control in hex.
XO=<xx><xx>
sets the XOFF/XON codes for outward flow control in hex.
B=<xx>
sets the alternate bell value in hex. Not yet available.
Perhaps the simplest form of PROTOCOL sets the baud rate:
>PROTOCOL 3 19200
The preceding statement sets the speed of line 3 to 19200 baud. The next example
sets the baud rate on line 3 to 1200 and enables both inward and outward XON/X-OFF protocols:
>PROTOCOL 3 1200 XI XO
11-6
Refer to the UniVision Command Reference Guide for more details about LISTLINE-CHARS and PROTOCOL.
Accessing Communication Lines
UniVision handles all serial communication devices in the same manner. A
terminal, for instance, connects to a communications port via a serial cable. It
communicates with the system across a line linked to a user process. The system
directs input to the process and output from the process to that communications
line. Thus, line 1 links to process 1. When the user turns on the terminal, the
system displays a logon prompt and the Logon processor monitors input on the
line.
An unlinked line is a line not attached to a process, referred to as an available line.
In order for your process to receive input from an available line, you must attach
the line to your process.
CONVERSE accesses an available communications line. It attaches the line to the
current process to enable it to use the line for input and output. Once CONVERSE
attaches the line, the process begins to act in a pass-through mode. It sends
characters received from the line through the process to the terminal, and
characters coming from the terminal through the process to the communications
line.
In other words, while the process is in CONVERSE mode, it sends what you type
at the terminal out to the communications line, instead of the process interpreting
it. The process linked to that line on the other system handles input. It sends the
output from that process to the system and displays it at the terminal. It continues
to send input out from the communications line until you press <ESC X>. This
command detaches the line from the process and ends the communication session
Example
This example shows how you might establish a connection between two systems,
A and B. As a result of this connection, a user working on system A is able to log
on to system B. First of all, you establish the physical connection: connecting line
5 on system A by direct cable or by modem to line 3 on system B. Link line 3 of
system B to process 3. The user is working at a terminal connected to line 2 on
system A. There is a link between the status of all lines on system A.
This is how to log on to system B, knowing that there is a connection between line
5 on the current system and system B:
•
Use UNLINK-LINE to unlink line 5 from the process associated with it.
This makes it an available line.
•
Use CONVERSE to attach line 5 to the current process, that is, process 2
connected to line 2. It is now possible to converse to line 5.
Data Communications
11-7
•
Dialup Connection: If the connection between system A and system B is
via modems, you must set up communication with the modem. You must
instruct the modem, in its own command language, to dial the other
system. On a Hayes-compatible modem, send the string 'ATDT phonenumber'.
•
Once you have established the connection, the Logon processor on
system B sends a logon prompt to the terminal. At the prompt, type the
user ID and password. If the logon is successful, system B sends the
login message and the terminal receives it.
•
Log off to end the remote logon session and return to the O/S login. Do
this by performing a :QUIT at UCL or by entering OFF at UCL followed
by QUIT at the Logon Please prompt.
•
Disconnect the modem. On a Hayes-compatible modem, enter the
command ATH to hang up the modem.
•
To end the communications session and exit CONVERSE mode, enter the
escape sequence <ESC-X> at the terminal. The process interprets the
escape sequence, and it detaches line 5 from the current process. (Line 5
remains unlinked.)
•
Use LINK-LINE to link line 5 to process 5.
If you require a more complicated use of a modem line, recommended practice is
nd
to acquire the outgoing line for sole UniVision use. In the 2 step above substitute
ACQUIRE-LINE instead of LINK-LINE.
The preceding example shows how to log on to a remote machine using
CONVERSE over an RS232 line and a network connection. In addition, you can
use software products such as UniComms to conduct the communications session.
In addition to providing a remote logon capability, UniComms permits file
transfer between UniVision systems. For more details refer to the UniVision
UniComms Reference Guide.
Changing the State of the Line
A line used for communications must be available if you want to use it to initiate a
connection with another system. If you want to use the same line to allow the
other system to initiate the connection, you must link the line to a process (to
provide a user process.) The state of a line, whether linked or available,
determines which system can initiate a logon session. For a dialup connection that
handles either incoming or outgoing calls, you must change the status of the lines
prior to use. To maintain a bi-directional line, users need to have access to LINKLINE and UNLINK-LINE by copying them to their account or by gaining access to
SYSPROG.
11-8
For example, if you have unlinked line 5 on a system, it means that you can use it
to call another system but that system cannot call and get a logon prompt. You can
use LINK-LINE to change the state of the line to 'linked', and the system displays a
logon prompt. You might decide to keep the communications line linked at all
times, except when being used explicitly for dialling out. Or, for security
purposes, you might require to keep it as an available line, prohibiting anyone
from dialling in.
Unlinking and Linking Lines
UNLINK-LINE and LINK-LINE are powerful commands that can change the state
of any line, you should use them with caution if you copy them to a user's Master
Dictionary.
UNLINK-LINE breaks a link between a line and the process. In addition, it breaks
any attachment between the line and the process. It makes unlinked and
unattached lines ‘available’, that is, it is possible to link and attach them to any
process. Its syntax is:
UNLINK-LINE line
line
number of the line you want to unlink.
When you unlink the line successfully, the system displays the following message:
[8012] Line n Unlinked
where n is the line you specified. If the line is unlinked or detached already, the
system does not display a message when you enter UNLINK-LINE.
LINK-LINE links a communications line to a process. It is not possible for the line
to be linked or attached to another process already.
LINK-LINE line-process [(U)]
line
number of the line you want to link.
process
number of the process to which you want to link the link.
U
breaks any existing link or attachment between the specified
line and any other process and links the specified line and
process.
For example:
>LINK-LINE 8-7
[8010] Line 8 linked to process 7
links line 8 to process 7.
Data Communications
11-9
Attaching a Line
LINE-ATT, which requires SYS1 privileges, attaches the specified line to the
current process. When you have attached a line to a process, the process has
exclusive use of that line. No other process can use the line for input or output
until you detach the line with LINE-DET.
LINE-ATT line [(U)]
line
number of the line you want to attach.
U
breaks the attachment of any other process to the specified
line and attaches that line to the current process. You require
SYS2 privileges to use this option.
When you attach the line successfully, the system displays the following message:
[8013] LINE n ATTACHED
where n is the specified line. If you specify a line attached currently or linked to
another process, the system displays the following message:
[8011] Line in use
If the line selected is not a valid RS232 line the system displays the following
message.
[8015] Illegal line number
If you use CONVERSE, there is no need to attach the line as a separate step. The
UniVision BASIC statement SEND can direct output to another line, even if you
have not attached the line to the user process, providing that you have acquired the
line or linked it to a line running UniVision currently. However, GET requires that
you attach the line to the process before it can read from that line. Refer to the
UniVision BASIC Reference Guide for more information on SEND and GET.
Detaching a Line
LINE-DET, which requires SYS1 privileges, detaches the specified line from the
current process, making the line accessible to other users.
LINE-DET line [(U)]
line
number of the line you want to detach.
U
breaks the attachment of the specified line to the current or
any other process. You require SYS2 privileges to use this
option.
When you detach the line successfully, the system does not display a message.
11-10
If the system has not attached the specified line to the process, it displays the
following messages:
[1141] NOT ATTACHED!
Acquiring a UNIX Line
ACQUIRE-LINE obtains UNIX line for later use by UniVision. The syntax is:
ACQUIRE-LINE m
m
specific line number.
The UniVision line number requested must relate to an unused UNIX line, that is,
if the line is already in use by UNIX or UniVision you cannot acquire it.
You use ACQUIRE-LINE prior to UniVision use to prevent UNIX from interfering
with the protocol settings of the line when not being used by UniVision.
Listing Acquired Lines
LIST-ACQUIRED-LINE lists all UNIX lines obtained for use by UniVision.
LIST-ACQUIRED-LINE [m[-n]] [(N)] [(P)]
m
m-n
range of numbers.
If you do not specify line numbers it displays all acquired
lines.
N
disables the paging of the display.
P
prints the output to the assigned printer.
If the line or range is not valid the system displays the following message:
[1145] Illegal Specification Number n
where n is the invalid number.
The following is an example of a typical display of LIST-ACQUIRED-LINE:
Line
0000L
0002L
0003LA
0010L
Process
0000*
0002
0003
0010
Acq PID
26476
26476
26476
26476
UNIX PID
125791
25541
84308
53619
UNIX Device Name
/dev/console
/dev/term/002
/dev/term/003
/dev/term/010
If the system only displays the heading it has not acquired any lines.
Data Communications
11-11
An explanation of the display is as follows:
Line
UniVision line number.
Process
Matching UniVision Process number for a particular
UniVision line
L
Indicates a linked process
A
Indicates an attached process.
*
Indicates you are running the verb from your
process.
Acq PID
UNIX Process ID for the Acquired Line Monitor program
that runs whenever you acquire a line for UniVision.
UNIX PID
UNIX Process ID for a particular line as a further crossreference between UNIX and UniVision
UNIX Device Name
Cross reference to the actual UNIX line connected to the
UniVision line.
Releasing Acquired Lines
RELEASE-LINE releases a line acquired previously by UniVision, using
ACQUIRE-LINE, back to UNIX.
RELEASE-LINE m
m
RELEASE-LINE releases a line acquired previously by UniVision back to UNIX,
whereupon UNIX takes control of that line and resets its line protocol.
If the line number is illegal the system displays the following error message.
[8015] Illegal line number
When the system releases the line to UNIX it displays the following message.
[UV8017] Acquired line is released
It the system has not acquired the line, that is, released already, the system does
not display an error message.
Using CONVERSE
Once you have established a conversation across an available line, you can use
CONVERSE for two-way communications. The syntax is:
11-12
CONVERSE line
line
line you want to attach to your process.
In order to attach a line to the process with CONVERSE, the line must be available
- that is, no other process can be linked or attached to it. You must have set up
transmission characteristics for the line attached with CONVERSE and set up the
line linked to the process correctly with PROTOCOL.
When you attach the line successfully, the system displays the following message:
LINE ATTACHED!
and the process is in CONVERSE mode. For example, to unlink and detach line 7
from another process, and attach it to the current process, perform the following:
>UNLINK-LINE 7
[8012] Line 7 Unlinked.
>CONVERSE 7
LINE ATTACHED!
Two-way communication is now possible between the terminal and a device
connected to line 7. While in CONVERSE mode, CONVERSE interprets <ESC>.
Enter <ESC>-<ESC> to send one <ESC> to the conversed line.
To exit CONVERSE mode and return to UCL, press <ESC>, and press X (it must
be upper-case X). The system displays the following message when you exit
CONVERSE mode:
LINE DETACHED!
Because CONVERSE accesses data one character at a time, you cannot stack input
to this verb in a Proc or UniVision BASIC program.
Using BASIC Programs
Custom UniVision BASIC programs can make the most of the communication
capabilities of UniVision. It is possible for a UniVision BASIC program that uses
SEND and GET to send and receive data via the line. It is possible to control what
goes on in the user process in addition to controlling what happens over multiple
communications lines.
Data Communications
11-13
A process can have as many lines as it wants attached to it. Attachment gives the
originating process exclusive control over that line; that is, no other process can
receive input from or send output to an attached line. Using GET, the originating
process can now receive input from two lines, the line originally linked to it and
nd
the 2 line it has attached to itself. In addition, using SEND, the originating
process can send output to any unattached line on the system, even if linked to
another process.
In addition, you could use a UniVision BASIC program to monitor a
communications line. A program might verify that a user has permission to use the
modem, offer a selection of the systems it is possible to reach, and submit
commands to the modem to dial up the remote system.
The following example of a custom data communications program achieves
greater security by monitoring access to the modem from the outside. It verifies
the ID of the user dialling in and calls the user back.
To create this application, it is necessary to set up an account synonym in the
SYSTEM Dictionary for an account name DIALUP. It is a Q-pointer to the
SYSPROG account:
001
002
003
004
005
006
007
008
009
010
DIALUP
Q
SYSPROG
SYS2
U
17
You use SYSPROG to gain access to LINK-LINE and UNLINK-LINE, but it could
be any account that has these verbs available.
Next, create a Logon Proc in the Master Dictionary of the account. The following
lists the DIALUP:
11-14
DIALUP
001 PQ
002 C FRONT END FRO MODEM PORT/PROCESS
003 HMSG !0 I AM ON
004 P
005 RI
006 C BELOW GETS NNP WHERE NN IS MY PORT. 1NNP IS POSSIBLE
007 S1
008 U31AD
009 P
010 HCREATE-FILE
011 A1
012 H 1 5
013 P
014 HLINK-LINE
015 A(1,2)
016 P
017 HDEBUG-OFF
018 P
019 C INVOKE BASIC PROGRAM FRONTEND TO PROMPT USER
020 C WITH FAKE LOGON PROMPT AND VALIDATE ENTRY
021 C THE PROGRAM PLACES THE PORT NUMBER IN THE INPUT
022 C BUFFER AS PARAMETER 2 AND RETURNS THE STATUS AS
023 C "OK" OR "BAD".
024 HRUN BP FRONTEND
025 STON
026 A1
027 P
028 C UPON RETURN, INPUT BUFFER PARAMETER 2 IS PURE NUMERIC
029 HUNLINK-LINE
030 A2
031 P
032 C CHECK INPUT BUFFER PARAMETER 3 FOR "OK"; ELSE MUST BE "BAD"
033 C SO LOGOFF USER
034 IF A3=OK GO 20
035 HMESSAGE !0 IMPROPER ATTEMPT
036 P
037 HOFF
038 P
039 20 CONTINUE
040 C AT THIS POINT, SHOULD RELINK LINE, USING PARAMETER 2 AND
041 C RUN A USER-SUPPLIED PROGRAM DIALBACK THAT SENDS THE
042 C USER-SUPPLIED PHONE NUMBER TO THE MODEM AND MAKES THE
CONNECTION
043 C THEN IT MIGHT DROP TO UCL OR RUN AN APPLICATION MENU
044 CHRUN CBP DIALBACK
045 CSTON
046 CA1
047 CP
048 X AT UCL: USE EXIT TO DISCONNECT FROM SYSTEM.
049 C EXIT IS A CUSTOM-PROC WHICH INVOKES THIS PROC
You can find a description of what this Proc does shortly.
Data Communications
11-15
Next create a Proc in SYSPROG called SETUP-MODEM. You can execute this
Proc from UCL. It prompts the user to identify the line and process number
connected to the modem.
SETUP-MODEM
001 PQ
002 C START A PROCESS FOR THE MODEM.
003 C PROMPTS FOR LINE NUMBER USED BY MODEM, UNLINKS LINE
044 C AND THEN STARTS A PHANTOM PROCESS RUNNING ON THE LINE.
005 C THIS PROC COULD BE RUN FROM UCL OR PLACED IN
006 C USER-COLD-START PROC WITH LINE NUMBER HARD-CODED RI
007 O WHAT LINE/PROCESS+
008 S1
009 IP
010 IF #A1 XNO ACTION
011 IF A199 XTOO BIG
012 IF A1 # 0 IF A1 # 00 IF A1 # 000 GO 20
013 X NOT ALLOWED ON PORT 0
014 20 CONTINUE. NO CHECKING FOR "LINE IN USE"
015 HUNLINK-LINE
016 A1
017 PP
018 HECHO-OFF
019 A1
020 PP
021 HPROTOCOL
022 A1
023 H+XI,+XO (C)
024 PP
025 HLOGON
026 STON
027 A1
028 H,DIALUP,CUSTOMER
029 PP
030 XSIMPLE EXAMPLE
The SETUP-MODEM Proc unlinks the process from the line and sets the line
transmission characteristics using PROTOCOL. It logs on the DIAL UP account.
Logging in runs the DIALUP Proc. The DIALUP Proc begins by determining
what line number the user of the SETUP-MODEM Proc is at. It returns a twodigit number followed by the letter P. Thus it returns 02P if the user is on process
2. It creates a log file under that name. It links that process to the line controlling
the modem and the DIALUP Proc invokes the UniVision BASIC program
FRONT-END.
11-16
FRONTEND
001 * FRONTEND IS SIMPLE EXAMPLE OF A SECURE
002 * PROC BUFFER TO START=NP. COULD ALLOW 1 NNP IF 99
003 * IF OK, BUFFER BECOMES 'NNP NN OK' WHEN DONE
004 PROMPT";CNT=0
005 HELLO='LOGON PLEASE-006 INPUT PORTFILE; * TEMP FILE CREATED BY DIALUP PROC, WHICH
ALSO SUPPLIES NAME
007 PORTNUM=FIELD(PORTFILE,'P',1)
008 PROCWRITE PORTFILE:' ':PORTNUM 'R%%':'BAD';*WRITE TO PROC
INPUT BUFFER
009 OPEN",PORTFILE ELSE STOP
010 CLEARFILE;* CLEAR OUT ANY OLD ITEMS IF FILE EXISTS
011 WRITE TIMEDATE() ON 'STARTED';* CREATE ITEM NAMED
012 100 * GET RESPONSE
013 PRINT HELLO:;INPUT USER
014 IF USER='ALPHA,BETA,GAMMA' THEN GOTO 200;* VALID LOGIN
015 * GIVE THREE TRIES
016 CNT=CNT+1;IF CNT3 THEN STOP
017 GOTO 100;* GARBAGE ON PHONE LINE?
018 200 * GET PHONE NUMBER FOR CALLBACK
019 PRINT 'ENTER PHONE NUMBER TO RETURN CALL':;INPUT WHERE
020 WRITE WHERE ON 'CALLBACK'
021 PROCWRITE PORTFILE:'':PORTNUM:' OK';* WRITE OK TO PROC INPUT
BUFFER
022 STOP
023 END
The FRONTEND program prompts the user to supply a valid login ID. It
communicates with the DIALUP Proc by placing parameters in the PROC input
buffer. If it validates the user, the input buffer contains the string OK, otherwise, it
contains BAD. The user is given 3 chances to supply a valid ID. Remember, the
logon prompt output by FRONTEND is a fake and not one generated by the
system. The idea is to restrict system access via modem to those who know the
special access key coded into the FRONTEND program. In this case, it is
ALPHA, BETA, GAMMA. If the user supplies the correct access key, the program
prompts the user to supply a phone number so that the system can call back.
At this point control passes back to the DIALUP Proc, which checks for OK in the
primary input buffer. If it is not there, the system logs off the DIALUP account. If
it is there, the DIALUP Proc passes control to the DIALBACK program.
DIALBACK (not shown) drops the connection and submits a command to the
modem to call the user back, using the phone number supplied by the
FRONTEND program. Once it has established the connection, the program might
exit to UCL or run an application-specific program.
These programs have increased the level of security by 1) validating the user; 2)
initiating the connection with a remote user; 3) keeping a log of activity on this
line.
Data Communications
11-17
Refer to the UniVision BASIC Reference Guide for more information on
controlling a communication line from a program.
Possible Problems
These are potential problems to look out for.
If someone sends a message to two physically connected machines, that message
nd
nd
goes out the line to the 2 machine. The 2 machine is looking for a user ID and,
st
st
not getting it, this outputs the logon prompt to the 1 machine. The 1 machine
nd
responds as the 2 did. This is called ping-ponging.
Often a user unlinks a line from a process before logging that process on for
communications. After logging on, the system links the line and the process
begins communicating when the system normally outputs the welcome banner.
Typically, UniVision operates in full-duplex mode. The system only displays a
character typed on a terminal when UniVision echoes it back. If echo is off and
the terminal is in half-duplex mode, the character displayed is due to the terminal.
Communications most often require echo to be off unless the transmitting
machine expects to get everything back and does not echo it back again - another
example of ping-ponging, often interspersed with bells (character 7) when the
type-ahead buffer becomes full.
11-18
Section 12
B+TREE FILES AND SECONDARY INDEXING
A database's storage mechanism must provide a good balance of concurrent A
database's storage mechanism must provide a good balance of concurrent access,
disk space utilisation and item access time.
UniVision bases the traditional storage structure it uses on the static hashed file.
The static hashed file storage structure offers extremely quick random access to
data, but suffers when there is a requirement for sorted access. In addition, since
this storage structure's size is pre-determined at file creation by the user, there is a
sacrifice of disk space utilisation or access time as the amount of data in the file
changes.
The B+Tree storage structure offers solutions to the above problems and has
become the defacto standard for storing items into a database file, but creates a
new set of performance issues. UniVision uses the latest techniques to address
performance as explained later in this Section.
Static Hashed Files
Static hashed files distribute database items across a user pre-determined number
of database file groups based on the item's id. The reason for this distribution is an
attempt to keep each group filled with an equivalent number of items and to
reduce the number of items that the system needs to search when retrieving the
item. Since the system stores the file in many groups, users can access and modify
the file concurrently as long as each is in a different group.
As long as the user has sized the file properly (the correct number of groups),
access to an individual item is extremely quick, usually requiring only a single
disk page access. For files that contain a static amount of data, proper sizing is a
simple job of analysing the number and size of items stored in the file. For files
that contain a varying amount of data, this is not possible. Improperly sized files,
waste disk space or require excessive disk activity to process overflowed groups.
When sorted access to data is unimportant, hashed files offer a simple solution. In
many database applications, order is important, such as reports in alphabetical
order.
B+Tree Files and Secondary Indexing
12-1
B+Trees Files
B+Trees offer solutions to all the issues raised above for static hashed files.
B+Trees are dynamic structures that guide the storage mechanism to the proper
disk page through a tree-like series of pointers starting at a base page, called the
root. Each page, called a node, contains fixed number of entries (called the
B+Tree's order) containing information to nodes containing entries with id's
either less than or greater than the current node. The last nodes in these series of
pointers are called leaf nodes.
An important property of B+Trees is that they stay balanced, that is the number
of nodes from the root node to each leaf node is the same. The user achieves this
by only ever adding new items into leaf nodes. If the leaf node overflows, the
system splits the node into two and promotes the middle item to the node above.
The system repeats this process node by node up the tree until a node does not
overflow. If the root node overflows, the system splits it and places the middle
item in a new root node, thus maintaining balance.
I
C
A
B
F
D
L
E
G
H
J
K
M
O
N
P
Q
Figure 12-1: Simple B+Tree
12-2
Issues with B+Trees
B+Trees offer a great advancement for the storage and access of database data, but
they also have some issues:
•
Wasted Disk Space: Since each node contains a fixed-number of entries,
there can be a wastage of disk space if you store smaller items. It is
necessary to store larger items indirectly which would waste space in the
node as well.
•
Sorted Access: Although the system stores the data effectively in sorted
access, providing sorted access is a complicated procedure of traversing
up and down the tree from node to node.
•
Concurrent Access: Semaphores or locks usually maintain concurrency,
because the algorithms for maintaining the balance of the tree requires
modification of multiple nodes, the usual method is to lock the entire
B+Tree. This method effects concurrent access adversely.
UniVision B+Trees
UniVision's implementation of B+Trees uses the latest state-of-the-art techniques
to address each of the above issues.
The way to resolve wasted disk space is by packing entries together using
variable-length entries and storing as many entries per node that fit. This results in
a different number of entries per node and thus is called a variable-order B+Tree.
The user can simplify sorted access by storing all data in the lowest level nodes,
called leaf nodes. This technique is known as a B+Tree structure. Since all the
data resides in the leaf nodes, a simple link from each leaf node to the next
provides a simple sequential sorted access to the data.
Thus the upper level nodes of a B+Tree, called branch nodes, form an index to
the data in the leaf nodes. Since the branch nodes only serve as an index to the
data in the leaf nodes, it is only necessary to store a limited number of keys in the
branch nodes. Although this requires additional disk space, it reduces the height of
the tree allowing quicker access to the actual data.
Since B+Tree branch nodes only provide an index to the data, the user does not
have to store the entire key in these nodes. They only have to store enough of the
key to identify which branch to take. This technique is known as prefix indexing.
This reduction in the size of the keys allows the user to compress the index further
thus reducing the amount of disk space required, possibly reducing the height of
the tree even further and thus improving the navigation to the data.
12-3
G
C
A
B
E
C
M
I
D
E
F
G
H
K
I
J
O
K
L
M
N
O
Q
P
Q
Figure 12-2: UniVision B+Trees
Solutions to the concurrency control issue should be simply matter of locking the
next node and releasing the previous node while searching down the tree for a
particular item, since the system has effectively separated the data into different
nodes. The technique is known as crabbing locks. This technique causes a
problem because the algorithms for maintaining balance require the user to
modify nodes from the leaf nodes to the root node, thus requiring them to set the
locks in the opposite direction. Having locks set in both directions would create a
deadlock condition. UniVision addresses this issue by a technique called
deferred promotion. When a node overflows, the system splits it into two nodes,
but defers the modification of upper level node until the next time the user
searches the tree.
UniVision's B+Tree implementation uses state-of-the-art advancements to the
original concept on B+Trees. By the use of B+Tree techniques, prefix-indexing,
crabbing locks and deferred promotion it provides very effective performance,
concurrent access and efficient sorted access.
12-4
The Need for Secondary Keys
When VISION query statements do not detail specific item IDs, it is not possible
to identify individual items without performing whole file scans. Of course, this
results in poor performance, particularly when the number of items in the result is
significantly smaller that the total number of items in the file being queried. For
example, imagine a STOCK file where the item ID is the stock line number and
one of the attributes details unit price:
>LIST STOCK WITH LINE-NUMBER = “120265”
specifies a single item ID and thus accesses the desired item directly.
>LIST STOCK WITH UNIT-PRICE = “1.00”
does not specify any item IDs and thus requires a full scan of all items in the stock
file.
If the user knows that they are to query specific attributes frequently, such as
UNIT-PRICE above, it makes sense to enable direct item access through those
attributes rather than always requiring full file scans.
In other words, the item ID constitutes the primary method for accessing items
quickly within a file, and is, therefore termed the primary key of the file. It should
be possible to specify alternate methods of direct access via attributes that appear
frequently in VISION queries, such as attributes, are often termed alternate, or
secondary, keys. This is the purpose of indexing.
Types of Index
The following types of index are available:
•
Hash
•
Left Justified Index.
•
Left Justified B+Tree
•
Right Justified B+Tree
Hash Index
A hash index gives the best performance where the user uses the attribute they
want to index in equality tests, rather than less-than and greater-than comparisons.
A hash index is appropriate for any type of attribute justification, that is, it does
not matter what is in line nine of the attribute definition.
12-5
Left-Justified B+Tree
A Left-justified B+Tree index gives the best performance where the user
references the attribute they want to index in VISION queries that perform lessthan and greater-than comparisons on that attribute. A Left-justified B+Tree stores
items in sorted alphabetic order and is thus appropriate for all attribute
justifications apart from right justification, which requires numeric rather than
alphabetic order.
To create a left-justified B+Tree index use the following:
>CREATE-INDEX filename attribute-name (B)
Right-Justified B+Tree
As with the Left-Justified B+Tree index, a Right-Justified B+Tree index is
appropriate when VISION queries reference the attribute as part of a less than or
greater than comparison. A Right-Justified B+Tree stores items in sorted numeric
order and is thus appropriate for only right-justified attributes, that is, where an R
appears in line nine of the attribute definition.
To created a right-justified B+Tree index use the following:
>CREATE-INDEX filename attribute-name (R)
Index Administration
It is possible to add an index to a file using CREATE-INDEX. The user must create
the index before they can build it using BUILD-INDEX. Setting up a secondary
index is a two-step process. First, the user must create or define the index using
CREATE-INDEX, then they must build the index using BUILD-INDEX.
To disable an index, (make it inactive) use DISABLE-INDEX. When the user
disables the index the system no longer updates it or uses it in any VISION
queries. To enable an index (make it active) use ENABLE-INDEX.
The user rebuilds an index to reflect the current state of the attribute it represents
using BUILD-INDEX. BUILD-INDEX builds a secondary index from a normal
hashed data file. It builds a newly created index for a data file that already
contains data.
The user deletes an index using DELETE-INDEX. This deletes the index definition
and the index table.
For more details on the above commands, refer to the UniVision Command
Reference Guide.
12-6
Section 13
DATABASE TRIGGERS
Triggers are BASIC subroutines that control the behaviour of the database system.
The programmer attaches BASIC trigger code to a UniVision file on one or more
redefined hooks. The filing system executes triggers automatically whenever it
encounters one of these hooks, whether it be by the system editor, a BASIC
program, or a Visual BASIC client. Triggers maintain history or cross reference
files or enforce business rules and database constraints. Triggers are an integral
part of UniVision's strategy to provide a feature rich traditional environment with
all the tools required for the migration to client-server.
Although very important in maintaining the integrity of your data, UniVision
triggers are flexible enough to do much more. It is possible to use UniVision's
triggers to search history or archive files when an item does not exist in the
current live database.
Adding Data Integrity to an Application
A significant percentage of a typical application program is the enforcement of
Business Rules that range from the commercial (for example, value ranges for
credit limits) to the procedural (for example, the user wants all updates to the
customer file logged to a history file).
Traditionally, the user embeds business rules in application code. In many very
old applications the user would have duplicated the same code at many points
throughout the application, this caused well-known maintenance headaches. In
more well considered implementations, the user implements business rules as
libraries of subroutines called explicitly at many points throughout the application.
Embedding business rules in application code has served us well for many years,
however, as applications mature, the user adds new rules, and changes old rules,
there is a significant burden on the programmer ensuring that the whole
application follows all rules.
Furthermore, once the user is outside the protection of the application (in the
editor for example) there is simply no way to enforce business rules at all.
Without these database constraints the integrity of your data suffers.
Database Triggers
13-1
The system should enforce business rules automatically and on a system-wide
basis ensuring the integrity of the data. If the user accepts the intent of business
rules as the protection of data going into and coming out of the filing system, then
the only sensible location for business rules is in the filing system itself.
UniVision unlike other multi-dimensional database management systems has a
solution to this ongoing problem. The solution is called database triggers. Triggers
put business rules and data constraints where they belong; in the database.
Trigger Hooks – How They Work
Triggers are a series of hooks embedded within the UniVision environment. There
are four major categories of hooks: READ, WRITE, DELETE, and READNEXT.
Although major category names match BASIC statement keywords, it is possible
to invoke triggers throughout the whole of UniVision, not just BASIC. For
example, using the editor FI command (which writes an item to disk) executes any
applicable WRITE triggers. Similarly, FD (which deletes an item from disk)
executes any applicable DELETE triggers.
The Trigger hooks are available automatically within the UniVision environment,
however, it is the responsibility of the application to build the actual Trigger
procedures called by the various database functions or hooks.
Within each major category there are a number of specific hooks to which the user
can attach triggers:
READ Hooks
There are three READ hooks available for use before or after a read to the
UniVision environment.
WAY-BEFORE-READ (WBR)
Before starting the read operation and before setting any
applicable new item locks and releasing any applicable old
item locks.
AFTER-SUCCESSFUL-READ (ASR)
After reading the required item successfully, and after setting
any applicable new item locks and releasing any applicable
old item locks.
AFTER-FAILED-READ (AFR)
After determining that the required item does not to exist and
after setting any applicable new item locks and releasing any
applicable old item locks.
13-2
WRITE Hooks
There are five WRITE hooks available for use before, during or after a write, or
update, to the UniVision environment.
WAY-BEFORE-WRITE (WBW)
Before starting the write operation and before setting any
item locks.
JUST-BEFORE-INSERT (JBI)
After determining that the item to be written does not to
exist, that is, this is a new item, and after setting any
applicable new item locks but before releasing any
applicable old item locks.
AFTER-INSERT (AI)
After writing the new item to disk and after setting any
item locks released.
JUST-BEFORE-UPDATE (JBU)
After determining that the item to be written exists, that is,
this is not a new item, and after setting any applicable new
item locks but before releasing any applicable old item locks.
AFTER-UPDATE (AU)
After updating the item on disk and after setting any
item locks.
DELETE Hooks
There are four DELETE hooks available for use before, during or after a Delete to
the UniVision environment.
WAY-BEFORE-DELETE (WBD)
Before starting the delete operation and before setting any
item locks.
JUST-BEFORE-SUCCESSFUL-DELETE (JBSD)
After locating the item to be deleted and after setting any
applicable new item locks but before releasing any
applicable old item locks have been.
Database Triggers
13-3
AFTER-SUCCESSFUL-DELETE (ASD)
After deleting the item from disk and after setting any
item locks.
AFTER-FAILED-DELETE (AFD)
After determining that the item to be deleted does not exist
and after setting any applicable new item locks and releasing
any applicable old item locks.
READNEXT Hooks
There are three READNEXT hooks available for use before or after a readnext
operation to the UniVision environment.
WAY-BEFORE-READNEXT (WBR)
Before starting the READNEXT operation.
AFTER-SUCCESSFUL-READNEXT (ASR)
After the READNEXT succeeded in returning the next value
from the file being iterated.
AFTER-FAILED-READNEXT (AFR)
After the READNEXT failed because you have exhausted
the file being iterated.
Anatomy of a Trigger
A trigger is a BASIC subroutine that accepts no parameters, but has a single
common list, and returns a status value:
001 SUBROUTINE VALIDATE-CUST
002 *
003 $INCLUDE BASICLIB TRIGGER.COMMON
004 * Attribute 5 of an item in the customer file is a count of the number
005 * of orders received to date.
006 * An update which sets the order count below zero is rejected :
007 IF ITEM$<5> < 0 THEN
008
Status = "ORDERS TO DATE < 0"
009 END ELSE
010 *
011 * Valid customer records are copied to a log file
012 *
013 IF LOG.FILE.IS.OPEN = 0 THEN
014
OPEN "CUSTOMER-LOG-FILE" TO LOG.FILE ELSE ABORT 201, "LOG-FILE"
015
LOG.FILE.IS.OPEN = 1
016 END
017 WRITE ITEM$ ON LOG.FILE, ID$
018 Status = 1
019 END
020*
021 RETURN Status
13-4
Trigger Common Area
The Trigger common area allows applications programmers a way of passing
information between application programs and Triggered procedures. The
common area is as follows:
COMMON.FILE$
File variable attached to the trigger.
FILENAME$
Name of the file to attach to the trigger.
ID$
Item ID of the item you are manipulating.
ITEM$
Item you are manipulating, not for DELETE triggers.
OLDITEM$
Old value of item, for WRITE and DELETE triggers.
HOOKTYPE$
Type of trigger hook, for example: AFTER-INSERT
RESERVED$(14)
Reserved for future use.
USER$(80)
! Note:
Scratch pad area, can be used by the application.
The trigger code can only modify the ITEM$ and
USER$(80) variables. All other variables in the common
list are 'read-only'.
Local Variables
The first time the user executes a trigger after opening a file, the system sets all of
its local variables to zero. On prior executions, all local variables retain the values
they had when the user last executed the trigger. The example above exploits this
facility to open a log file the first time it writes a valid item.
Return Values
A trigger must return a value that evaluates to a positive integer, a negative
integer, or zero.
! Note:
Any non-numeric string evaluates to zero (such as
Status = "ORDERS TO DATE < 0" in the example
above).
If the return value evaluates to a positive number then the filing system continues
with the current READ, WRITE, DELETE, or READNEXT operation as normal.
Database Triggers
13-5
If the return value evaluates to zero, the filing system abandons the current
READ, WRITE, DELETE, or READNEXT operation immediately and, in the
case of BASIC, takes the ELSE path of that operation.
If the return value evaluates to a negative number, the filing system abandons the
READ, WRITE, DELETE, or READNEXT operation immediately and, in the
case of BASIC takes the THEN path of that operation.
The BASIC function SYSTEM(223) provides the return value of the most recently
executed trigger.
! Note:
An error in the execution of a trigger, if for example the
trigger does not exist, returns a value of "BAD
TRIGGER".
Trigger Examples
ADD-WRITE-TRIGGER CUSTOMER BP VALIDATE-CUST (WBW
Attaches a compiled trigger (BP VALIDATE-CUST) to the way before write
hook of the CUSTOMER file.
! Note:
If VALIDATE-CUST was a catalogued program, there
would be no need to specify the program file (BP) in this
command.
DISABLE-READ-TRIGGER STOCK (AFR
Disables the trigger attached to the after failed read hook of the STOCK file.
ENABLE-DELETE-TRIGGER SALES (A
Enables all delete triggers for the SALES file.
DROP-READNEXT-TRIGGER INVOICES (ASR
Drops the trigger from the after successful READNEXT hook of the INVOICES
file.
Trigger Procedures Verb Definitions
The system attaches trigger procedures to hooks on a file based via the following
UCL commands:
ADD-READ-TRIGGER filename trig (hook
filename
13-6
name of the file that engages the triggered procedure that
must exist on the current account.
trig
name of the compiled and catalogued UniVision BASIC
program that must exist on the current account.
hook
specifies where the user wants to add the triggered
procedure:
WBR
ASR
AFR
WAY-BEFORE-READ
AFTER-SUCCESSFUL-READ
AFTER-FAILED-READ
ADD-WRITE-TRIGGER filename trig (hook
filename
trig
hook
procedure:
WBW
JBI
AI
JBU
AU
WAY-BEFORE-WRITE
JUST-BEFORE-INSERT
AFTER-INSERT
JUST-BEFORE-UPDATE
AFTER-UPDATE
ADD-DELETE-TRIGGER filename trig (hook
filename
trig
hook
procedure:
WBD
JBSD
ASD
AFD
WAY-BEFORE-DELETE
JUST-BEFORE-SUCCESSFUL-DELETE
AFTER-SUCCESSFUL-DELETE
AFTER-FAILED-DELETE
ADD-READNEXT-TRIGGER filename trig (hook
filename
trig
Database Triggers
13-7
hook
procedure:
WBR
ASR
AFR
WAY-BEFORE-READNEXT
AFTER-SUCCESSFUL-READNEXT
AFTER-FAILED-READNEXT
The system disables triggers (that is, stopped from firing) via the commands:
DISABLE-READ-TRIGGER filename ({hook|A}
filename
hook
specifies the triggered procedure the user wants to disable.
WBR
ASR
AFR
A
WAY-BEFORE-READ
AFTER-FAILED-READ
all triggers attached to READ hooks.
DISABLE-WRITE-TRIGGER filename ({hook|A}
filename
hook
WBW
JBI
AI
JBU
AU
A
WAY-BEFORE-WRITE
JUST-BEFORE-INSERT
AFTER-INSERT
JUST-BEFORE-UPDATE
AFTER-UPDATE
all triggers attached to WRITE hooks.
DISABLE-DELETE-TRIGGER filename ({hook|A}
filename
hook
WBD
JBSD
ASD
AFD
A
13-8
WAY-BEFORE-DELETE
AFTER-FAILED-DELETE
all triggers attached to DELETE hooks.
DISABLE-READNEXT-TRIGGER filename ({hook|A}
filename
hook
WBR
ASR
AFR
A
WAY-BEFORE-READNEXT
all triggers attached to READNEXT hooks.
The system re-enables triggers (that is, activated for firing) via the commands:
ENABLE-READ-TRIGGER filename ({hook|A}
filename
hook
specifies the triggered procedure the user wants to re-enable.
WBR
ASR
AFR
A
WAY-BEFORE-READ
AFTER-FAILED-READ
all triggers attached to READ hooks
ENABLE-WRITE-TRIGGER filename ({hook|A}
filename
hook
WBW
JBI
AI
JBU
AU
A
WAY-BEFORE-WRITE
JUST-BEFORE-INSERT
AFTER-INSERT
JUST-BEFORE-UPDATE
AFTER-UPDATE
all triggers attached to WRITE hooks
ENABLE-DELETE-TRIGGER filename ({hook|A}
filename
Database Triggers
13-9
hook
WBD
JBSD
ASD
AFD
A
WAY-BEFORE-DELETE
AFTER-FAILED-DELETE
all triggers attached to DELETE hooks
ENABLE-READNEXT-TRIGGER filename ({hook|A}
filename
hook
WBR
ASR
AFR
A
WAY-BEFORE-READNEXT
all triggers attached to READNEXT hooks
The system drops and removes triggers via the commands:
DROP-READ-TRIGGER filename ({hook|A}
filename
hook
specifies the triggered procedure the user wants to remove.
WBR
ASR
AFR
A
WAY-BEFORE-READ
AFTER-FAILED-READ
all triggers attached to READ hooks
DROP-WRITE-TRIGGER filename ({hook|A}
filename
hook
WBW
JBI
AI
JBU
AU
A
13-10
WAY-BEFORE-WRITE
JUST-BEFORE-INSERT
AFTER-INSERT
JUST-BEFORE-UPDATE
AFTER-UPDATE
all triggers attached to WRITE hooks
DROP-DELETE-TRIGGER filename ({hook|A}
filename
hook
WBD
JBSD
ASD
AFD
A
WAY-BEFORE-DELETE
AFTER-FAILED-DELETE
all triggers attached to DELETE hooks
DROP-READNEXT-TRIGGER filename ({hook|A}
filename
hook
WBR
ASR
AFR
A
Database Triggers
WAY-BEFORE-READNEXT
all triggers attached to READNEXT hooks
13-11
Section 14
VIRTUAL FILE SYSTEM INTERFACE –
EXTERNAL FILE HANDLING
Introduction
The Virtual File System Interface - eXternal File Handler (XFH) functionality of
rd
UniVision allows access to data stored with 3 party file handlers. Access is
transparent at the UniVision file level, and allows all UniVision processes
rd
read/write access to 3 party file data directly without any special syntax.
UniVision BASIC applications can reference and modify data stored in these files.
Functional Description
Dynamically loaded XFH drivers provide functionality. A link gives information
about the driver location and parameters required to gain access to the required
data file. It appears to behave as if the file was a standard UniVision file, thus
allowing all UniVision processors access to the data without change.
Normally, the user creates a standard UniVision dictionary file to hold the XFH
link item and VISION dictionary items so that it is possible to use the selection
and report generator on external files.
External File Handler Link Item Format
Format:
001
002
003
004
005
006
007
008
009
010
linkname
Q{X|U}
driver-path
parameters
reserved
retrieval-codes
update-codes
conversion
correlative
justification
width
Virtual File System Interface – External File Handling
14-1
Q{X|U}
Specifies that item is an XFH link. X defines that the drive provides all necessary
locking. U defines that standard UniVision mechanisms should be used in addition
to the locking provided by the driver.
driver-path
Specifies UNIX path to XFH driver.
parameters
Specifies driver-specific parameters needed to reference the file data referred to
by the XFH link.
reserved
Not used.
retrieval-codes
Specifies the standard UniVision file retrieval code used on the XFH file.
update-codes
Specifies the standard UniVision file update code used on the XFH file.
conversion
Specifies the standard UniVision conversion codes applied to the XFH item-id.
correlative
Specifies the standard UniVision correlative codes applied to the XFH item-id.
justification
Specifies the standard UniVision justification applied to the XFH item-id.
width
Specifies the standard UniVision file width applied to the XFH item-id.
External File Handler Driver
The user must provide the XFH driver as shared object executable, this must
provide functions that support the following interface.
14-2
External File Handler Interface
The driver MUST provide the following function. The following line must appear
at the top of the driver source code
#include “Uvxfh.h”
All function return one of the following values
Return Value
Reason
UVXFH STATUS SUCCESSFUL
Successful completion
UVXFH STATUS NOT FOUND
Requested item not found
UVXFH STATUS LOCKED
Requested item locked
UVXFH STATUS FATAL
Any other error
In the following descriptions ‘file’ refers to the XFH-specific data structure that
behaves as the UniVision file, and ‘item’ refers to the UniVision formatted data
identified by an ‘id’ contained within ‘file’
Open
Synopsis
int (*Open) (void** ppHandle,char,parameters [ ]);
Description
Called when the user initiates access and before any other function. The system
passes XFH-specific parameters contained in attribute 3 of XFH link item as a
null terminated character string. The function needs to return the address of a
structure in ppHandle that it passes to all other functions to control access the
‘file’ identified by parameters.
Close
Synopsis
int (*Close) (void* pHandle) ;
Description
Called when the user no longer needs access to the ‘file’ identified’ by pHandle,
they do not need pHandle after this call. If the system allocated the structure
pointed to by pHandle dynamically, the user should deallocate it in this function.
Clear File
Synopsis
int (*ClearFile) (*void pHandle) ;
14-3
Description
Called when all ‘items’ in the ‘file’ should be deleted
Read
Synopsis
int (*Read) (void* pHandle, char id[], char** ppItem);
Description
Called when the user requires to retrieve the ‘item’ identified by id from the ‘file’
associated with pHandle. ppItem needs to return the address of buffer containing
‘item’.
ReadU
Synopsis
int (*ReadU) (void* pHandle, char id[], char** ppItem) ;
Description
Called when the user requests an exclusive lock on an ‘item’ identified by ‘id’ and
the ‘item’ they need to retrieve it from the ‘file’ associated with pHandle. ppItem
needs to return the address of buffer containing ‘item’.
Write
Synopsis
int (*Write) (void* pHandle, char id []) ;
Description
Called when the user wants to write the item identified by id on the ‘file’
associated with pHandle. It should release any lock on the ‘item’ identified by
‘id’.
WriteU
Synopsis
int (*WriteU) (void* pHandle, char id [ ]) ;
Description
Called when the user wants to write the item identified by id on the ‘file’
associated with pHandle. It should maintain an exclusive lock on the ‘item’
identified by id.
14-4
Delete
Synopsis
int (*Delete) (void* pHandle, char id []) ;
Description
Called when the user wants to delete the item identified by id on the ‘file’
associated with pHandle. It should release any lock on the ‘item’ identified by id.
Lock
Synopsis
int (*Lock) (void* pHandle, char id []) ;
Description
Called when the user wants to lock the ‘item’ identified by id on the ‘file’
associated with pHandle exclusively.
Release
Synopsis
int (*Release) (void* pHandle, char id []) ;
Description
Called when the user wants to remove the lock on the ‘item’ identified by id on
the ‘file’ associated with pHandle.
ReleaseAll
Synopsis
int (*ReleaseAll) (void* Phandle) ;
Description
Called when the user wants to remove all locks on ‘items’ locked on the ‘file’
associated with pHandle.
IterateStart
Synopsis
int (*IterateStart) (void* pHandle, char** ppId, char** ppItem) ;
Description
Called when the user wants to start the sequential retrieval of the ‘ids’ and ‘items’
on the ‘file’ associated with pHandle. ppID needs to return the address of a buffer
st
containing the 1 ‘id and ppItem needs to return the ‘item’.
14-5
IterateNext
Synopsis
int (*IterateNext) (void* pHandle, char** ppId, char** ppItem) ;
Description
Called when the user wants to make the next sequential retrieval of the ‘ids’ and
‘items’ on the ‘file’ associated with pHandle. ppID needs to return the address of
st
a buffer containing the 1 ‘id and ppItem needs to return the ‘item’. This function
always calls IterateStart() before it executes.
IterateDone
Synopsis
int (*IterateDone) (void* pHandle) ;
Description
Called when the user no longer needs the sequential retrieval of the ‘ids’ and
‘items’ on the ‘file’ associated with pHandle. This function always calls the
IterateStart() before it executes when the user no longer needs iteration.
External File Handler Support Routines
COBOL Record Transfer
It is possible to translate COBOL records containing fixed length binary typed
fields to and from UniVision records with the help of the methods provided by the
‘Translator’ C++class.
Format Definition
Specifies the format of the fields so that it is possible to perform conversion
between the fixed length binary-type fields and the UniVision delimited ASCIII
attributes. The format definition string defines each field with a comma separated
field specifier as summarised below:
14-6
Type
Syntax
Alphanumeric
Alength
Binary
B[N]length
‘N’
specifies
CPU-specific
storage,
instead
of
Most
Significant Byte (MSB) first
Numeric Display
D[L][S]length
‘L’
Notes
specifies
Leading
Sign
‘S’ specifies Separate Sign
Floating Point
F{1|2}
‘1’ specifies Single precision
‘2’ specifies Double precision
Packed Decimal
P[S]length
Filler
+length
Offset
@offset
Multi-field
delimiter
ID
&delimiter
‘S’ specifies Signed
key-format only and must be first
specifier
Special specifiers handle multiple occurrences of a field or fields in the format
below. These special format specifiers deal with the conversion of multi-valued
field that exist in COBOL as an OCCURS specification. It is possible to use
multiple specifiers between the occurrence-start and occurrence-end to deal with
the occurrence of records and require that the size of each record be given.
Multiple ‘Values’ occurrences may exist within ‘Attribute’ occurrences, and
multiple ‘Subvalues’ occurrences may exist within ‘Values’ occurrences as long
as the size values include the total of those multiple occurrences.
Occurrence-start number[*size],specifiers…occurrence-end
occurrence
start
occurrence
end
Attribute
(
)
Values
[
]
Sub-values
{
}
Type
14-7
Storage Representation
The binary storage representation of each supported type is as follows:
Alphanumeric
This is a fixed-length ASCII data field. Translation from this type removes trailing
spaces. Translation to this type truncates at length if necessary.
Binary
Holds numeric data in length byte in pure binary two’s complement format. The
system stores the number Most Significant Byte (MSB) first, unless the user uses
the Native (N) option, that specifies that they want the number stored in CPUspecific native order.
Numeric Display
Holds numeric data as ASCII digit characters 0 to 9 one digit per byte of storage.
Negative values have bit 6 (hex value ’40) set on the last digit character. If the
st
user specifies the Leading Sign (L) option, the system sets bit 6 of the 1 digit
character of negative values. If the user specifies the Separate Sign (S) option, the
system places an ASCII PLUS (+) or MINUS (-) sign in the first or last digit
position, depending on the Leading Sign (L) option.
Floating Point
Holds floating point data in CPU-specific single precision or double precision
floating point binary numbers, specified by option 1 or 2 respectively.
Packed Decimal
Holds numeric data in binary-coded-decimal format. Each byte holds two decimal
digits. The system holds the sign, depending on the Signed (S) option, in the last
half-byte digit position as a hex value F for unsigned values, hex value C for
positively signed values, or hex D for negatively signed values.
Program Interface
Use of the Translator class requires the following line in the source code
#include “Translator.h”
In addition, the user must link Translator.0 in the final executable.
14-8
TranslateCobolKey
Synopsis
static boolean_t TranslateCobolKey{
char cobolBuffer[],
int cobolBufferSize,
char univIdBuffer[],
char formatBuffer[]);
Description
Translates the record key defined by formatBuffer from the record in cobolBuffer
with a size of cobolBufferSize to a UniVision item-id in univIdBuffer. The buffer
provided by univBuffer must be large enough to accept the largest item-id
possible.
Diagnostics
Returns B_FALSE if an error exists in the syntax of formatBuffer.
TranslateUnivId
Synopsis
static boolean_TranslateUnivID(
char cobolBuffer[],
char univIdBuffer[],
Description
Translates the UniVision item-id in univIdBuffer to the record key defined by
formatBuffer in cobolBuffer with a size of cobolBufferSize.
Diagnostics
Returns B_FALSE if an error exists in the syntax of formatBuffer or you would
exceed the cobolBufferSize. Also sets the maximum UniVision Id buffer size
required retrieved by MaximumUnivID().
TranslateCobol
Synopsis
static boolean_t TranslateCobol(
char univBuffer[],
char cobolBuffer[],
14-9
Description
Translates the record data defined by formatBuffer from the record in cobolBuffer
with a size of cobolBufferSize to a UniVision item in univBuffer. The buffer
provided by univBuffer must be large enough to accept the largest possible
Diagnostics
Returns B_FALSE is an error exists in the syntax of formatBuffer.
TranslateUniv
Synopsis
static boolean_t TranslateUniv(
char cobolBuffer[],
char univBuffer[],
Description
Translates the UniVision item univBuffer to the record data defined by
formatBuffer in cobolBuffer with a size of coboBufferSize. Also sets the
maximum UniVision Item buffer size required, retrieved by the
MaximumUnivItem() function.
Diagnostics
Returns B_FALSE if an error exists in the syntax of formatBuffer or you would
exceed the cobolBufferSize.
MaximumUnivId
Synopsis
static int MaximumUnivId();
Description
Returns the maximum UniVision Id buffer size possible with the format string
passed in formatBuffer to the TranslateUnivID() function
Synopsis
static int MaximumUnivItem();
Description
Returns the maximum UniVision Item buffer size possible with the format string
passed in format buffer to TranslateUniv().
14-10
Section 15
SETTING UP A DISTRIBUTED FILING
SYSTEM
This Section describes how you set up two or more systems to provide access to
files across multiple UniVision Environments.
You can define a distributed file as any file not resident in the local UniVision
database. A distributed file must, therefore, be resident in either of two locations:
on another machine or another copy of UniVision on the same machine.
UniVision facilitates access to all distributed files via a simple extension to the
standard Q-Pointer mechanism. A user simply provides location information for a
non-local account (in line two of the Q-Pointer) and specifies the remainder of the
Q-Pointer as normal.
! Note:
The Distributed Filing System access in UniVision
works with the TCP/IP communications protocol.
TCP/IP must, therefore, be running on your network.
UniVision does not, however, restrict you to any specific
lower-level protocol. This facility will work equally well
over Ethernet, FDDI, ATM, etc.
You need to perform the following steps to set up a Distributed Filing System
between two or more systems running the UniVision Environment.
•
Define the naming characteristics of each system.
•
Set up the TCP/IP network.
•
Add required configuration information to the /etc/services file.
•
Install UniVision on each system.
•
Set-up the Remote and Local paths between the two systems using the
Uvsetup menus.
•
Start the Server on the remote machine.
•
Set-up the required Q-pointers in the main UniVision system to access
information on the remote system.
Setting Up A Distributed Filing System
15-1
Define the Naming Characteristics in Each System
To illustrate the set-up of Distributed Filing System and provide consistent
examples, we will use an imaginary corporate network. Figure 15-1 shows an
example network made up of several nodes together with its topology.
System Host Name: univclient
IP Address: 199.1.1.101
Real UniVision Name (login): univc
Logical UniVision Name: univclientlink
System Host Name: univserver
IP Address: 199.1.1.102
Real UniVision Name (login): univs
Logical UniVision Name: univclientlink
The Logical UniVision Name is a label that identifies the TCP/IP connection, for
example, univserver link
Figure 15-1: Example Network Topology
Figure 15-1 is a simple network of two systems. The main system is called
univclient (client) and the backup system is called univserver (server). The IP
addresses for the system are 199.1.1.101 and 199.1.1.102 respectively. Also, the
UniVision login is univc on the univclient system and univs on the univserver
system.
Set-up the TCP/IP Network
To deliver data between two TCP/IP hosts, it is necessary to move the data across
the network to the correct host, and within the appropriate host to the correct user
or process. The TCP/IP protocol uses three schemes to accomplish this task:
15-2
Addressing
IP address, identifying every host on the network uniquely
and delivers data to the correct host.
Routing
Gateways deliver data to the correct network.
Multiplexing
Protocol and port number deliver data to the correct software
module within the host.
Each of the above functions: addressing between hosts, routing between networks,
and multiplexing between layers is necessary to send data between two cooperating applications across the network.
Hosts Table
The hosts table is a text file associating IP addresses with host names. On most
UNIX systems, the table is stored in the file /etc/hosts. Each table entry in
/etc/hosts contains the IP addresses and the host names associated with each
remote system.
IP addresses are usually written as 4 decimal numbers separated by periods. Each
of the 4 numbers is in the range 0 to 255 representing the decimal values possible
for a single byte. Because the bits that identify class are contiguous with the
network bits of the address, it is possible to lump them together and look at the
address as composed of full bytes of network address and full bytes of host
address. If the first byte of an address is:
•
less that 128, it is a class A address. The 1 byte is the network number,
and the next three bytes are the host address.
•
from 128 to 191 is a class B address. The 1 two bytes identify the
network, and the last two bytes identify the host address.
•
from 191 to 224 is a class C address. The 1 three bytes are the network
address, and the last byte is the host address.
•
greater than 224, the address is reserved.
st
st
st
In our example, Figure 15-1 the IP addresses used are class C addresses. The IP
addresses chosen are just an example and might not work within an existing
network. Very small sites, not connected to the Internet, can use this
configuration. However, systems connected to the Internet or very complex
networks require the help of your Network administrator. Network Administration
is a topic beyond the focus of this documentation.
To assign IP addresses please confer with your Network Administrator or the O/S
documentation provided with your system. Another good source of information on
Network Administration is a book called TCP/IP Network Administration
authored by Craig Hunt and published by O’Reilly & Associates, Inc.
! Note:
If you do not set-up the /etc/hosts file at this point the
system prompts you to set-up a host address and aliases
when using UVsetup menu entry 13, Maintain
Local/Remote UniVision Names.
15-3
Using the example above, Figure 15-2 shows the /etc/hosts file for the univclient
system:
#
# Table of IP addresses and host names for univclient
#
199.1.1.101
univclient
127.0.0.1
localhost me
199.1.1.102
univserver
199.1.1.10
JohnsPC
199.1.1.11
MikesPC
Figure 15-2: The /etc/hosts File on the System Called univclient
Figure 15-3 shows the /etc/hosts file for the univserver system:
#
# Table of IP addresses and host names for univserver
#
199.1.1.102
univserver
127.0.0.1
localhost me
199.1.1.101
univclient
199.1.1.10
JohnsPC
199.1.1.11
MikesPC
Figure 15-3: The /etc/hosts File on the System Called univserver
! Note:
The LOCAL UniVision definition defaults to an alias
called me. In order for the communications process to
work, add the me alias to the localhost or loop back IP
address. If you fail to add this alias, you will not be able
to start the Server (:START-MASTER-SERVER) on the
univserver system.
Set-up the pse.conf File
! Note:
This file set-up is required for AIX-Based systems. If you
are setting up a Non-AIX system, skip to testing the IP
connection.
The pse.conf file is located in the /etc directory. This file must be set-up in order
to get TCP/IP connections working properly on an AIX-based system. Using the
cat command or vi editor verify the PSE communication protocols are set-up
properly.
15-4
# PSE drivers
d+
d+
d+
d+
dlpi
dlpi
dlpi
dlpi
en
et
tr
fi
/dev/dlpi/en
/dev/dlpi/et
/dev/dlpi/tr
/dev/dlpi/fi
#streams
#streams
#streams
#streams
dlpi
dlpi
dlpi
dlpi
ethernet driver
802.3 driver
token ring driver
FDDI driver
# PSE communication protocols
d+
d+
d+
d+
xtiso
xtiso
xtiso
xtiso
unixdg
unixst
udp
tcp
/dev/xti/unixdg
/dev/xti/unixst
/dev/xti/udp
/dev/xti/tcp
#
#
#
#
unix domain datagrams
unix domain byte-stream
UDP/IP
TCP/IP
# PSE modules
m
m
timod
tirwr
#TLI module
#TLI read/write interface
If any of the above lines is commented out by having a # character at the
beginning of the line, remove the # and reboot the system. Should you require
further assistance please check with your network administrator or AIX
documentation.
Test the IP Connections
Before proceeding to the next step, test to assure the network is configured
properly and all cables are connected properly. This can be accomplished by using
ping.
ping is a UNIX network utility that indicates whether a remote host can be
reached. In addition, ping displays statistics about the packet loss and deliver
time.
Using the example above, pinging or testing the univserver system can be
accomplished by typing ping 199.1.1.102 or ping univserver from either
systems. Any failures show that a problem exists with the network or the cables
are not installed properly.
In addition, after you have successfully pinged both systems, you can use telnet to
make sure network application software is working properly. For example, you
can use telnet univserver from the root prompt on the univclient system to test the
software and connections between the two systems. Any failures must be
corrected before going to the next step.
Install UniVision on Each System
The next step is to load UniVision on each system. This is accomplished by
following the installation instructions in the UniVision Installation Instructions &
Administration Guide provided with the software media.
15-5
The only exception, for clarity is to change the UniVision login name. This is
accomplished by changing the installation path which is the first question after
entering the pkgadd command.
! Note:
The installp command in AIX does not allow you to
create different logins for UniVision. Therefore, only the
standard UniV login is supported.
Using the example in Figure 15-1, during UniVision Installation, the prompt
UniVision installation path? (default:/home/UniVision)[?,q].
requires the following responses:
System
Response
Login
univclient
/home/UniVision/univc
univc
univserver
/home/UniVision/univs
univs
! Note:
You can use the default path of /home/UniVision and still
maintain the default login of UniV. However, by having
different logins (and passwords) allows for easier
administration of the systems. (The difference in this
documentation is for clarity only. You are not required to
have different logins.)
Add Configuration Information to the /etc/services
File
The UniVision Environment requires a definition in the /etc/services file on both
the client, univclient, and server, univserver, system. This is accomplished by
using the vi editor and adding the following:
#
# UniVision Services
#
UniVision
12345/tcp
The word UniVision and tcp are required. The UniVision configuration number
can be any five-digit numeric number and must be the same on both systems. For
example, Figure 15-4 shows that the univserver system should have the following
added to the /etc/services file.
! Note:
15-6
If you do not set-up the /etc/services file at this point, the
system prompts you to set-up UniVision services when
using UVsetup menu entry 13, Maintain Local/Remote
UniVision Names.
#
# Network services, Internet style
#
echo
7/tcp
echo
7/udp
discard
9/tcp
sink null
.
.
.
host_table
468/udp
#
# Unix specific services
#
.
.
.
bootpc
68/udp
listen
9100/tcp
listen
2766/tcp
#
# UniVision Services
#
UniVision
12345/tcp
Figure 15-4: The /etc/services File on the System Called univserver
! Note:
The above example is a copy of the /etc/services file on
an AT&T/NCR system. Each system requires different
services so do not change this file. Just add to the bottom
(or top) the lines in the above example in bold.
Set-up the Remote and Local Paths
The next step involves setting up the link between the two systems, the client
machine and the server machine. This example uses the following names for the
two machines, univclient for the client and univserver for the server. The client
machine, does not have any files stored on it, whereas the server machine does.
The next step is required on both systems. You must set-up both the
remote_univision_name and local_univision_names files on both systems.
When UniVision is installed, the local_univision_names file is automatically setup on both the univclient and univserver systems as shown in Figure 15-5. Since
UniVision sets up this file automatically, this display is added for clarity.
! Note:
Before making any changes to remote_univision_names
file, make sure the /home directory has write permissions
for other. If not, please use chmod to change the
permissions of the /home directory.
15-7
Maintain Local/Remote UniVision Names
(E)xit
------------------ Maintain -----------------(I)dentity Name (L)ocal Names (R)emote Names :- L
The format for the "/home/local_univision_names" file is:
Logical UniVision Name:Real UniVision Name@ System Host Name:Optional
Comment
The contents are:
<1>
univc:/home/UniVision:
(E)xit
(D)elete
(A)dd
:-E
Figure 15-5: Display of the Local Names on the univserver System
You are required to set-up the remote_univision_name file on both univclient and
univserver systems. This is accomplished by continuing with the same program in
UVsetup menu entry 13, Maintain Local/Remote UniVision Names.
! Note:
The system being used as the Server system must have a
Logical UniVision Name of LOCAL.
Figure 15-6, is a display of the program and entries required to create the
remote_univision_name file on the univserver system. In order to set the file
properly you need to answer three questions:
Logical UniVision Name
The name you want to give to the link from the main system
to the remote. In our sample configuration, univserver is the
server so you must call it LOCAL.
Real UniVision Name
The normal login from UNIX into the UniVision
environment on the univserver system. Our example loaded
UniVision into the univs directory, therefore, the login is
univs and the response to this field can only be univs
System Host Name
The system name entered in the /etc/hosts file. In our
example the system name is univserver.
! Note:
15-8
The Server is on the univserver system, the Logical
UniVision Name on the univserver system must be
entered as LOCAL.
(E)xit
------------------ Maintain -----------------(I)dentity Name (L)ocal Names (R)emote Names :- R
Logical UniVision Name:Real UniVision Name@ System Host Name:Optional Comment
The contents are:
<1> LOCAL:univs@me:
(E)xit
(D)elete
(A)dd
:- D
Enter line <number> of Name to delete :- 1
Delete:
LOCAL:UniV@me:
Are you sure? (Y/N) :- Y
There is an entry for "me" in "/etc/hosts" as follows:127.0.0.1 me loopback localhost
Do you also want to delete this entry? (Y/N):- N
"/etc/hosts" not modified.
Press any key to continue.<RETURN>
The file is empty or does not exist.
(E)xit
(A)dd
:- A
Enter the Logical UniVision Name (ESC to exit):- LOCAL
Enter the Real UniVision Name (ESC to exit):- univs
Enter the System Host Name (ESC to exit):- univserver
Enter an optional Comment:- Local Server on univserver link on univserver
system
There is an entry for "univserver" in "/etc/hosts" as follows:199.1.1.103 univserver
Please check that these details are correct.
Press any key to continue. <RETURN>
The format for the "./univision/admin/remote_univision_names" file is:
LogicalUniVisionName:RealUniVisionName@SystemHostName:Optional
Comment
The contents are:
<1>
LOCAL:Univs@univserver:Local univserver link on the univserver system
(E)xit
(D)elete
(A)dd
:-E
Figure 15-6: Addition of the Remote Names on the univserver System
15-9
When UniVision is installed, the local_univision_names file is automatically setup on the univserver system as shown in Figure 15-7. Since UniVision sets up this
file automatically, this display is added for clarity.
(E)xit
------------------ Maintain -----------------(I)dentity Name (L)ocal Names (R)emote Names :- L
Logical UniVision Name:Real UniVision Name@ System Host Name:Optional
Comment
The contents are:
<1>
univs:/home/UniVision:
(E)xit
(D)elete
(A)dd
:-E
Figure 15-7: Display of the Local Names on the univserver System
Figure 15-8, is a display of the program and entries required to create the
remote_univision_name file on the univclient (client) system. In order to set the
file properly you need to answer three questions:
Logical UniVision Name
The name you want to give to the link from the main system
to the remote. In our sample configuration, we are calling the
link univclientlink.
Real UniVision Name
The normal login from UNIX into the UniVision
environment on the univserver system. Our example loaded
UniVision into the univs directory, therefore, the login is
univs and the response to this field can only be univs.
System Host Name
The system name entered in the /etc/hosts file. In our
example the system name is univserver.
You are on the client system and attempting to access files on the server system,
therefore the Real UniVision Name is the Login from UNIX to UniVision on the
Server system, that is, univs, and the System Host Name is the Host Name of
the Server system, that is univserver.
15-10
(E)xit
------------------ Maintain -----------------(I)dentity Name (L)ocal Names (R)emote Names :- R
Logical UniVision Name:Real UniVision Name@ System Host Name:Optional Comment
The contents are:
<1> LOCAL:univc@me:
(E)xit
(D)elete
(A)dd
:- D
Enter line <number> of Name to delete :- 1
Delete:
LOCAL:Univc@me:
Are you sure? (Y/N) :- Y
There is an entry for "me" in "/etc/hosts" as follows:127.0.0.1 me loopback localhost
Do you also want to delete this entry? (Y/N):- N
"/etc/hosts" not modified.
Press any key to continue.<RETURN>
The file is empty or does not exist.
(E)xit
(A)dd
:- A
Enter the Logical UniVision Name (ESC to exit):- univclientlink
Enter the Real UniVision Name (ESC to exit):- univs
Enter the System Host Name (ESC to exit):- univserver
Enter an optional Comment:- univclient link on univclient system
There is an entry for "univserver" in "/etc/hosts" as follows:199.1.1.101 univclient
Please check that these details are correct.
Press any key to continue. <RETURN>
The format for the "./univision/admin/remote_univision_names" file is:
LogicalUniVisionName:RealUniVisionName@SystemHostName:Optional
Comment
The contents are:
<1>
univclientlink:Univs@univclient:univclient link on univclient system
(E)xit
(D)elete
(A)dd
:-E
Figure 15-8: Addition of the Remote Names on the univclient System
15-11
Start the Server on the Remote Machine
On the remote machine called univserver, you need to start the UniVision Server.
You accomplish this by logging to SYSPROG and typing :START-MASTERSERVER at the UCL prompt. The Master Server allows users on the main system
called univclient to access data on the remote system called univserver.
! Note:
You must stop the server, using :STOP-MASTERSERVER before you shut-down the system. If you do not
you cannot re-enter UniVision without resetting the
processor.
Set-up the Required Q-Pointers
To access files on the remote system called univserver you need to create Qpointers on the main system called univclient. This is accomplished by logging in
to the appropriate account on the univclient system and at UCL enter a Q-pointer
as follows:
Attr#
Definition
Example
0
Q-pointer key
CUSTOMERS
1
Q
Q
2
Account-name@
Logical-Remote-name
ACCOUNT@univclientlink
3
Filename
CUSTOMER
4
Not used
5
Retrieval lock
6
Update lock
7
Conversion specification
8
Not used
9
Justification
L
10
maximum field length
10
Process Size Limits
You must ensure that there are sufficient server processes, to achieve this you
should use option 10 of UVsetup.
15-12
! Note:
For details of this option refer to the section entitled
Maintain Process Size Limits in the Section entitled
UniVision Administration Utility.
You should allow at least one server process for each user process that is to use a
Remote File in the Distributed Filing System.
For example, if the system has 100 users of which, 35 are using the Distributed
Filing System at any given time, you should set:
•
size 140
•
servers 40
At worst, although this is overkill, double the number of users, for example:
•
size 200
•
servers 100
Remote Files in UniVision
Assume that there are two machines, one in London (local) and one in New York
(remote), and the user is located in London, before they can access files on the
machine in New York they must have set up the following:
In the directory /etc/hosts on both the local and remote machines enter:
internet-address aliases comments
internet-address
internet address of the machine in the form nnn.n.n.nn.
aliases
name of the internet address.
comment
any comment relevant to the machine.
Example
Assume that the machine in London has the internet address 192.1.1.90 with the
alias LDS10, and the machine in New York has internet address 192.1.1.91 with
the alias NYS10, the user would set up the following in the directory /etc/hosts:
192.1.1.90 LDS10
192.1.1.91 NYS10
Testing the Link
To test the linking is operating use telnet or ping.
telnet aliases
ping internet-address
15-13
internet-address
internet address of the machine in the form nnn.n.n.nn.
aliases
Example
Using the internet addresses and aliases of the previous example use the
following.
telnet LDS10 or ping 192.1.1.90
telnet NYS10 or ping 192.1.1.91
Once complete the user should set up the following in the directory /etc/services
on both machines.
Insert UniVision num
num
unique five digit decimal number that does not exist, this
must be the same on all machines.
Example
/etc/services
UniVision 12345/tcp
Accessing Remote Files
On the local machine the directory:
/directory/Uvname/univision/admin/remote_univision_names
should contain:
logical-name:remoteUV@remote-internet-address
directory
full pathname to the directory where UniVision is installed
on the local machine.
Uvname
name of UniVision on the local machine.
logical-name
logical name of the file on the remote machine.
remoteUV
name of UniVision on the remote machine.
remote-internet-address
internet address of the remote machine.
On the remote machine the directory:
/home/local-univision-names
15-14
should contain:
remoteUV:directory:
remoteUV
directory
on the remote system.
The directory:
/directory/Uvname/univision/admin/remote_univision_name
should contain:
LOCAL:logical-name@aliases
directory
on remote machine.
Uvname
logical-name
aliases
Local Machine
At the following prompt:
LOGON PLEASE:
enter the name of the account from which the user wants to access the remote
machine.
When the system displays the UCL prompt (>)enter the following:
ED MD logical name
logical-name
This should contain:
001 Q
002 rem-account@logical-name
003 rem-file
where:
rem-account
account name on the remote machine.
logical-name
rem-file
file name on the remote machine.
15-15
On Remote Machine
At the following prompt:
LOGON PLEASE:
enter
SYSPROG
at the UCL prompt (>) enter
:START-MASTER-SERVER
Listing Remote Files
To obtain a listing of a file from the remote machine enter
LIST logical-name
logical-name
Example
Assume that the local machine is in London, UniVision is installed in the
directory ‘unistore’, and UniVision is known as Lduniv. The remote machine is
located in New York, UniVision is installed in the directory /unistore/Nyuniv,
UniVision is known as Nyuniv, the logical name of the file is NYOREDERS, the
remote account name is WINDEMO and the remote file name is ORDERS. The
following should be set up
LONDON
The directory:
/unistore/london/univision/admin/remote_univision_names
should contain:
NYORDERS:Nyuniv@LDS10
NEW YORK
The directory:
/home/local_univision_name
should contain:
Nyuniv/unistore/Nyuniv:
The directory
/unistore/NYUNIV/univision/admin/remote_univision_names
15-16
should contain:
LOCAL:NYORDERS@NYS10
Accessing Files
LONDON
LOGON PLEASE: SYSPROG
>ED MD ORDERS
001 Q
002 WINDEMO@NYORDERS
003 ORDERS
.FI
NEW YORK
LOGON PLEASE: SYSPROG
>:START-MASTER-SERVER
Listing Files
LIST NYORDERS
15-17
A Guide to the UniVision
System
Index
!
.A command
.C command
Options
.E command
.G command
.K command
.L command
.M command
.MU command
.O command
.P command
.Q command
.R command
.S command
.U command
.X command
.Z command
:AUTHORISE verb
:FILELOAD verb
:INIT-DISK verb
:INIT-SYSTEM verb
:INIT-TAPE verb
:START-MASTER-SERVER verb
:STARTSPOOLER verb
:STOP-MASTER-SERVER verb
? option
@ phrase
Creation
@TCL
<< verb
>> verb
6-22
6-22 - 6-24
6-22 - 6-23
6-21
6-21
6-24
2-10 - 2-11, 6-19 - 6-20
6-21 - 6-22
6-21 - 6-22
6-25
6-25
6-25
6-24
6-25
6-25
2-10 - 2-11, 6-20
6-25
8-3
8-5
8-4
8-4
8-4
15-12
8-3, 9-5, 9-6 - 9-7
8-5
9-14
3-15
8-15
6-15, 8-5
6-15, 8-5
A
A option
ACC file
Index
9-15
8-10
Index-i
Access communication lines
Acquire UNIX line
Attach line
Change state of line
Detach line
List acquired line
Release acquired lines
Unlink and link lines
Access remote files
Access files
List remote files
Local machine
Remote machine
Access tape drive
Access to SYSPROG account
Account
Account definition items
Creation
Deletion
File synonym items
User
Account options
Attributes
Base
Definition code
Item ID
Modulo
Password
Privilege level
Reallocation
Retrieval codes
Update codes
User process code
Width
Account management
SYSPROG account
SYSPROG commands
SYSTEM dictionary
Account management commands
Account options
Account synonym items
Account
Attributes
Definition code
Item ID
Account usage statistics
CHARGES verb
CHARGE-TO verb
Index-ii
11-7 - 11-12
11-11
11-10
11-8 - 11-9
11-10 - 11-11
11-11 - 11-12
11-12
11-9
15-14 - 15-17
15-17
15-16 - 15-17
15-15
15-16
10-3 - 10-5
8-1 - 8-2
1-8
4-8
2-1 - 2-2, 8-6
8-6
4-12
2-1 - 2-19
4-4 - 4-7, 4-12 - 4-15, 8-8
4-6 - 4-7
4-4 - 4-7
4-4
4-4
4-4
4-5
4-5
4-6
4-7
4-5
4-5
4-7
4-7
8-1 - 8-15
8-1 - 8-2
8-2 - 8-5
8-8 - 8-12
8-3
4-6 - 4-7
4-8
4-8
4-8
4-8
4-8
8-7 - 8-8
8-7 - 8-8
8-7 - 8-8
ACCOUNT-RESTORE verb
ACCOUNT-SAVE verb
Acquire UNIX line
ACQUIRE-LINE verb
Add configuration information to /etc/services file
Add data integrity to application
Add triggers
ADD-ACCOUNTS verb
ADDD verb
ADD-DELETE-TRIGGER verb
ADD-READNEXT-TRIGGER verb
ADD-READ-TRIGGER verb
ADD-WRITE-TRIGGER verb
ADDX verb
Advance to end-of-data
AMC
Analysing file structure
Anatomy of trigger
Local variables
Return values
Trigger common area
Trigger examples
Append data to tape
Append text
Assign item ids
Assign spooler specifications
Associate multi-valued attributes
Attach cartridge tape unit
Attach line
Attach tape device
Attribute
Attribute definition items
Attibutes
Attribute number
Conversions
Correlatives
Definition code
Item ID
Justification
Structure
Tag
Width
Attribute mark
Attribute number
Attributes
File definition items
File synonym items
Index
7-26, 8-5
7-26, 8-5
11-11
5-8, 11-2, 11-11
15-6 - 15-7
13-1 - 13-2
13-6 - 13-8
8-5
6-16
13-7
13-7 - 13-8
13-6 - 13-7
13-7
6-16
10-26
1-8
7-20
13-4 - 13-6
13-5
13-5 - 13-6
13-5
13-6
10-10
6-22
3-12
9-13 - 9-18
3-9
10-23 - 10-24
11-10
10-22 - 10-23
1-8
2-12
4-13
4-13
4-14
4-14
4-13
4-13
4-14 - 4-15
4-14
4-14
4-15
1-8
3-8
4-13
4-4 - 4-7
4-8
4-13
4-9 - 4-11
4-12
Index-iii
AUTO-LOGOFF verb
Options
Automatic logoff
AUTO-LOGOFF verb
6-4 - 6-5, 8-3
6-4 - 6-5
6-4 - 6-5
6-4 - 6-5
B
B option
B+Tree files
B+Tree files and secondary indexing
B+Tree files
Index administration
Issues with B+Trees
Need for secondary keys
Static hashed files
Types of index
UniVision B+Trees
Backup
Base
Basic operation of spooler
Command summary
Forms
Hold files
Print files
Printers
Summary of spooler features
Block size
1/2-inch tape
1/4-inch tape
4mm DAT tape
8mm DAT tape
CD-ROM device tape
Diskette device tape
BLOCK-CONVERT file
BLOCK-PRINT verb
BREAK key
BUILD-INDEX verb
BUILD-LOCK-XREF verb
BUILD-TR-INDEX verb
9-15
12-2
12-1 - 12-5
12-2
12-6
12-3
12-5
12-1
12-5
12-3 - 12-4
7-26
1-8
4-4
4-10
9-1 - 9-6
9-5 - 9-6
9-2 - 9-4
9-4 - 9-5
9-4 - 9-5
9-2 - 9-4
9-6
10-18
10-18
10-18
10-18
10-18
10-18
10-18
8-11
6-15
2-9 - 2-10
12-6
8-4
8-4
C
Cancel active print jobs
Cancel print jobs
Cancel active print jobs
Remove printer from system
Retain print files as hold files
Index-iv
9-21 - 9-22
9-21 - 9-23
9-21 - 9-22
9-22 - 9-23
9-22
Catalogued UniVision BASIC programs
Change printer's form queue
Change state of line
CHARGES verb
CHARGE-TO verb
Check print queue
Check status of printers
Choose command to modify
Clear file
CLEAR-FILE verb
CLEAR-GROUP-LOCKS verb
COBOL record transfer
Alphanumeric
Binary
Floating point
Format description
MaximumUnivId
Numeric display
Packed decimal
Program interface
Storage representation
TranslateCobol
TranslateCobolKey
TranslateUniv
TranslateUnivId
Column heading
Column width
Command summary
Communications line settings
COMPARE verb
Configure printers
Change printer's form queue
Initialise parallel printer
Initialise serial printer
Restart stopped printer
Contents of SYSPROG account
Controlling and dependent specifications
CONVERSE verb
Possible problems
Using BASIC programs
Conversions
Convert hold file to data file
Copy file items
Copy print file from tape
Copy SYSPROG commands
COPY verb
Options
Index
6-18
9-8 - 9-9
11-8 - 11-9
8-7 - 8-8
8-7 - 8-8
9-18 - 9-21
9-9 - 9-11
6-21
7-6 - 7-7
7-1, 7-6 - 7-7
8-4
14-6 - 14-9
14-8
14-8
14-8
14-6 - 14-7
14-10
14-8
14-8
14-8
14-8
14-9
14-9
14-10
14-9
3-9
3-10 - 3-11
9-5 - 9-6
6-5 - 6-6
8-5
9-7 - 9-9
9-8 - 9-9
9-8
9-8
9-9
8-2
4-20 - 4-21
5-8, 11-2, 11-12 - 11-17
11-18
11-13 - 11-17
3-9
4-14
4-10
9-28 - 9-29
7-8 - 7-11
9-31 - 9-32
8-5 - 8-6
6-17, 7-2, 7-8 - 7-11
7-8 - 7-9
Index-v
Correlatives
Correlatives and conversions
Date format
Dollar amounts format
Format dates
Format dollar amounts
Format times
Manipulate existing data
Stored format and output format
Time format
Translate data from another file
CPU
Create @ phrase
Create account
Create data file
Create data items
Assign item ids
Create database
Create database application
Create dictionary
Create dictionary entries
Associate multi-values attributes
Attribute number
Column heading
Column width
Conversions
Correlatives
Identify entry
Justification
Name attribute definition item
Create dictionary items in numeric sequence
Create file
Create data file
Create dictionary
Create dictionary entries
Create file in target account
Create new database
Create UniVision BASIC files
Select filename
Select modulo
Create file in target account
Create file synonyms
Create Q-pointers
SET-FILE verb
Create new database
Create Q-pointers
Create UniVision BASIC files
CREATE-ACCOUNT verb
Index-vi
3-9
4-14
4-10
4-21 - 4-25
4-23
4-22 - 4-23
4-23
4-22 - 4-23
4-23
4-23 - 4-24
4-21 - 4-23
4-23
4-25
1-8
3-15
2-1 - 2-2, 8-6
7-4 - 7-5
3-11 - 3-12
3-12
3-1 - 3-15
3-15
7-4
3-6 - 3-11
3-9
3-8
3-9
3-10 - 3-11
3-9
3-9
3-7 - 3-8
3-10
3-7
3-15
3-2 - 3-12, 7-3 - 7-6
7-4 - 7-5
7-4
3-6 - 3-11
7-6
7-5 - 7-6
7-6
3-3
3-3 - 3-4
7-6
7-14 - 7-16
7-14 - 7-15
7-15 - 7-16
7-5 - 7-6
7-14 - 7-15
7-6
8-3, 8-6
CREATE-BFILE verb
CREATE-FILE verb
Options
CREATE-INDEX verb
CT verb
7-6
3-4 - 3-5, 7-1, 7-3 - 7-6
7-4
12-6
6-18
D
Data communications
Access communication line
Command summary
Make connection
Overview
Set line characteristics and protocols
Data file
Creation
Data files
Data items
Creation
Database
Creation
Design
Database application
Creation
Database architecture
Database management system
Database triggers
Anatomy of trigger
Hooks
Date format
DE verb
Options
DEBUG-OFF verb
DEBUG-ON verb
Define default output specifications
Create @ phrase
Create dictionary items in numeric sequence
Define naming characteristics in each system
DEFINE-CURSOR verb
Definition code
File synonym items
Delete account
Delete file
DELETE hooks
Index
11-1 - 11-17
11-7 - 11-12
11-2
11-3
11-1 - 11-2
11-3 - 11-7
1-8
7-4 - 7-5
4-4
3-11 - 3-12
1-8
3-1 - 3-15
3-1 - 3-2
3-15
4-1 - 4-25
5-1 - 5-11
13-1 - 13-11
13-1 - 13-2
13-4 - 13-6
13-2 - 13-4
4-23
6-17, 7-11 - 7-12
7-11 - 7-12
6-16
6-16
3-14 - 3-15
3-15
3-15
15-2
8-4
4-4
4-8
4-13
4-9 - 4-10
4-12
8-6
7-7 - 7-8
13-3 - 13-4
Index-vii
Delete items
Delete multiple hold files
Delete statement from stack
DELETE verb
DELETE-ACCOUNT verb
DELETE-FILE verb
DELETE-INDEX verb
Design database
Destination options
Detach line
Detach tape unit
DEVICE-DETAILS file
DEVICE-ERRORS file
DEVICE-NAMES file
Dictionaries
File
Master
SYSTEM
Dictionary
Creation
Dictionary entries
Creation
Dictionary items
Verb definition items
Dictionary items in numeric sequence
Creation
Disable triggers
DISABLE-DELETE-TRIGGER verb
DISABLE-INDEX verb
DISABLE-READNEXT-TRIGGER verb
DISABLE-READ-TRIGGER verb
DISABLE-WRITE-TRIGGER verb
Distributed filing system
Access remote files
Add configuration information to /etc/services file
Define naming characteristics in each system
Install UniVision on each system
Process size limits
Remote files in UniVision
Set up
Set up remote and local paths
Set up required Q-pointers
Set up TCP/IP network
Start server on remote machine
Test link
DIVD verb
DIVX verb
Index-viii
7-12 - 7-13
9-30
6-24
7-2, 7-12 - 7-13
8-3, 8-6
7-1 - 7-2, 7-7 - 7-8
12-6
3-1 - 3-2
9-15 - 9-16
11-10 - 11-11
10-23
8-11
8-11
8-11
4-3 - 4-4
4-3
4-3
1-8
7-4
3-6 - 3-11
4-4 - 4-16
4-4 - 4-7
4-12 - 4-15
4-9 - 4-11
4-9
3-15
13-8 - 13-9
13-8
12-6
13-9
13-8
13-8
15-14 - 15-17
15-6 - 15-7
15-2
15-5 - 15-6
15-12 - 15-13
15-13
15-1 - 15-17
15-7 - 15-11
15-12
15-2 - 15-5
15-12
15-13 - 15-14
6-16
6-16
DOC-EDIT verb
Options
DROP-DELETE-TRIGGER verb
DROP-READNEXT-TRIGGER verb
DROP-READ-TRIGGER verb
DROP-WRITE-TRIGGER verb
DTR verb
DTX verb
Dump file to tape
DUMP verb
Options
6-17, 7-11 - 7-12
7-11 - 7-12
4-22 - 4-23
13-11
13-11
13-10
13-10
6-16
6-16
10-5 - 10-7, 10-27 - 10-28
5-2 - 5-3, 6-15, 8-4
5-2 - 5-3
E
ECHO verb
ECHO-OFF verb
ECHO-ON verb
ED verb
Options
Edit command line
Edit item
Edit stack
EDIT verb
Options
Enable stacker
ENABLE-DELETE-TRIGGER verb
ENABLE-INDEX verb
ENABLE-READNEXT-TRIGGER verb
ENABLE-READ-TRIGGER verb
ENABLE-WRITE-TRIGGER verb
Enter UCL command
Erase selected tape drives
ERRMSG file
Format of ERRMSG items
Examine account
List contents of items
List files
Examine contents of tape
Examine group in close detail
Execute previous statements
Exit UniVision environment
External file handler driver
External file handler interface
External file handler interface
Clear File
Close
Delete
IterateDone
Index
6-15
6-16
6-16
6-17, 7-2, 7-11 - 7-12
7-11 - 7-12
2-8 - 2-9
7-11 - 7-12
6-21
6-17, 7-2, 7-11 - 7-12
7-11 - 7-12
6-19
13-9 - 13-10
12-6
13-10
13-9
13-9
2-8
10-27
8-11, 8-13 - 8-15
8-13 - 8-15
2-12 - 2-17
2-14 - 2-17
2-13 - 2-14
10-29 - 10-30
7-22 - 7-24
6-20
2-5
14-2 - 14-6
14-3 - 14-6
14-3 - 14-4
14-3
14-5
14-6
Index-ix
External file handler interface (Continued)
IterateNext
IterateStart
Lock
Open
Read
ReadU
Release
ReleaseAll
Write
WriteU
External file handler link item format
conversion
correlative
driver-path
justification
parameters
Q{X|U}
retrieval-codes
update-codes
width
External file handler support routines
COBOL record transfer
External file handling
Functional description
Introduction
Extraction of information
Define default output specifications
14-6
14-5
14-5
14-3
14-4
14-4
14-5
14-5
14-4
14-4
14-1 - 14-2
14-2
14-2
14-2
14-2
14-2
14-2
14-2
14-2
14-2
14-6 - 14-9
14-6 - 14-9
14-1 - 14-9
14-2 - 14-6
14-6 - 14-9
14-1 - 14-9
14-1
3-13 - 3-15
3-14 - 3-15
F
F option
File
Creation
File access
Retrieve items
File creation
Attributes
Base
Conversions
Correlatives
Definition code
Item ID
Justification
Modulo
Realloaction
Index-x
9-15
7-3 - 7-6
5-4 - 5-7
5-6 - 5-7
3-2 - 3-12
2-12, 4-9 - 4-11
4-9 - 4-11, 4-12
4-10
4-10
4-10
4-9 - 4-10
4-9
4-10
4-10
4-11
File definition items (Continued)
Retrieval code
Update code
Width
File dictionary
File efficiency
Analysing file structure
Test file structure
File maintenance
Examine group in close detail
File efficiency
Reallocating files
File management
File management tasks
Clear file
CLEAR-FILE
COPY
Copy file items
Create file
CREATE-FILE
DELETE
Delete file
Delete items
DELETE-FILE
ED
EDIT
Edit item
Filename syntax
Item lists
MOVE-FILE
RENAME
File security
Retrieval codes
Update codes
File synonym items
Account
Definition code
Filename
Item ID
File synonyms
Creation
File system
UniVision
Filename
File synonym items
Filename syntax
FILE-SAVE verb
FILE-TEST verb
FIND verb
Form queue
Index
4-10
4-10
4-11
1-8, 4-3 - 4-4
7-19 - 7-22
7-20
7-20 - 7-22
7-19 - 7-25
7-22 - 7-24
7-19 - 7-22
7-24 - 7-25
7-1 - 7-25
7-1 - 7-13
7-6 - 7-7
7-1
7-2
7-8 - 7-11
7-3 - 7-6
7-1
7-2
7-7 - 7-8
7-12 - 7-13
7-1 - 7-2
7-2
7-2
7-11 - 7-12
7-2 - 7-3
7-3
7-1
7-1
7-16 - 7-19
7-17 - 7-19
7-17 - 7-19
2-12, 4-11 - 4-12
4-12
4-12
4-12
4-12
7-14 - 7-16
4-1 - 4-3
4-12
7-2 - 7-3
8-5
7-20 - 7-22
6-17
1-8
Index-xi
Format date
Format of ERRMSG items
@TCL
Logon messages
Format time
FORMAT verb
Forms
Forms queue option
Forward tape
Frame
Frame formats
DUMP verb
Physical item structure
4-23
8-13 - 8-15
8-15
8-15
4-23
10-13
9-2 - 9-4
9-15
10-24 - 10-25
1-8
5-2 - 5-4
5-2 - 5-3
5-4
G
Generate VISION reports
List contents of dictionary
Glossary
Group
GROUP verb
GROUP-LOCKS file
2-17 - 2-19
2-18 - 2-19
1-8 - 1-9
1-8
6-17, 7-22 - 7-23
8-11
H
H option
Hash index
HASH-TEST verb
Hierarchy
Hold file retention
Hold files
Hosts table
9-15
12-5
7-20 - 7-22
1-2 - 1-3
9-32 - 9-33
9-4 - 9-5
15-3 - 15-4
I
I option
IDATE verb
Identify entry
Include data from tape in reports
Index administration
Information
Extraction
Initialise parallel printer
Initialise serial printer
Install UniVision on each system
Issues with B+Trees
ISTAT verb
Item
Index-xii
9-16
8-2
3-7 - 3-8
10-28 - 10-29
12-6
3-13 - 3-15
9-8
9-8
15-5
12-3
7-20
1-8
Item ID
File synonym items
Item lists
ITEM verb
ITEM-LOCKS file
1-8
4-4
4-8
4-13
4-9
4-12
7-3
7-23 - 7-24
8-11
J
Justification
3-10
4-14 - 4-15
4-10
L
Left-justified B+Tree index
LINE-ATT verb
LINE-DET verb
LINE-PROTCOL verb
LINE-PROTOCOL verb
LINE-STATUS verb
LINK-LINE verb
List acquired line
List assignment status option
List contents of dictionary
List contents of items
List current tape device assignments
List files
List line and process characteristics
LLC verb
List stack
LISTABS verb
LIST-ACQUIRED-LINE verb
LISTCONN verb
LISTDEV verb
LISTDICT verb
LISTFILES verb
LIST-FILE-STATS verb
LIST-LINE-CHARS verb
LISTPEQS verb
Options
LISTPRO verb
LISTPROCS verb
LISTPTR verb
Options
LIST-SECUIRTY-LOG verb
Index
12-6
5-8, 11-2, 11-10
5-8, 11-2, 11-10 - 11-11
5-8
11-2
5-8, 11-2
5-8, 11-2, 11-9
11-11 - 11-12
9-14
2-18 - 2-19
2-14 - 2-17
10-19 - 10-20
2-13 - 2-14
6-7
6-7
6-19 - 6-20
9-5
5-8, 11-2, 11-11 - 11-12
6-18
5-8
6-18
6-18
8-4
6-7, 11-2, 11-5
9-5, 9-18 - 9-21
9-18
5-8
6-18
9-5, 9-9 - 9-11
9-9 - 9-10
8-3
Index-xiii
LIST-TR-INDEX verb
LISTVERBS verb
LLC verb
Local paths
Set up
Local variables
LOCKOUT verb
LOCKOUT-STATUS verb
LOCKS-XREF file
Log off
Log on
Log on and off
Automatic logoff
Log other users on and off
Log to other accounts
Logoff Proc
Logon Proc
Receive system messages
Restrict access to UCL
Restrict user access
Log other users on and off
Log to other accounts
Log to UniVision environment
Logical tape unit
Logoff Proc
Logon messages
Logon Proc
8-4
6-18
6-7, 11-5
15-7 - 15-11
13-5
8-3
8-3
8-12
2-4 - 2-5
2-3 - 2-4
6-1 - 6-5
6-4 - 6-5
6-4
6-4
6-3
6-2
6-3
6-2 - 6-3
6-2
6-4
6-4
2-2 - 2-3
1-9
6-3
8-15
6-2
M
Magnetic tape
Attach cartridge tape unit
Attach tape device
Detach tape unit
Examine contents of tape
Overview of production verbs
Overview of tape operations
Overview of utility verbs
Position tape
Select tape drive
Specify tape drive format
Transfer data to and from other systems
Troubleshooting
Write and read
Make connection
Managing files
Managing users
Manipulate existing data
Index-xiv
10-1 - 10-33
10-23 - 10-24
10-22 - 10-23
10-23
10-29 - 10-30
10-14 - 10-16
10-1 - 10-3
10-14
10-24 - 10-27
10-19 - 10-21
10-22
10-30 - 10-32
10-33
10-3 - 10-13
11-3
1-6 - 1-7
1-5 - 1-6
4-23 - 4-24
Manipulate hold files
Convert hold file to data file
Delete multiple hold files
Print hold file on screen
Select hold files
Spool hold file
Spool multiple hold files
View contents
Master dictionary
File synonym items
Proc
VISION keywords
MAXUSERS verb
Message items
MESSAGE verb
Messages
Logon
Miscellaneous administrative commands
MODEM-OFF verb
MODEM-ON verb
Modify previous statements
Modify spooler records
Modulo
Move to specified file
MOVE-FILE verb
MSG verb
MULD verb
Multi-valued attributes
MULX verb
9-23 - 9-30
9-28 - 9-29
9-30
9-28
9-29
9-28
9-30
9-26
1-9, 2-11 - 2-12, 4-3
2-12
2-12
2-12
2-12
2-12
2-12
8-3
8-9 - 8-10
6-15
8-15
8-5
8-3
8-3
6-20 - 6-22
9-30
1-9
4-5
4-10
10-25
7-1
6-15
6-16
4-17 - 4-20
6-16
N
Name attribute definition item
Need for secondary keys
New database
Creation
NEWAC file
NSELECT verb
3-7
12-5
7-5 - 7-6
8-12
6-17
O
O option
Open option
Index
9-17
9-17
Index-xv
Options
.C command
?
A
AUTO-LOGOFF verb
B
COPY verb
CREATE-FILE verb
DE verb
Destination
DOC-EDIT verb
DUMP verb
ED verb
EDIT verb
F
Forms queue
H
I
List assignment status
LISTPEQS verb
LISTPTR verb
O
Open
Parenthetical
Print to auxiliary port
Printer banner
PROTOCOL verb
R
Reassign print files
S
Select job priority
SP-ASSIGN verb
STARTPTR verb
T
T-DUMP verb
T-LOAD verb
T-READ verb
Organisation of information
Data file
File dictionary
MASTER dictionary
Structure of data
SYSTEM dictionary
Overflow area
Overflow table
Overview of data communications
Overview of production verbs
Overview of tape operations
Overview of utility verbs
Index-xvi
6-22 - 6-23
9-14
9-15
6-4 - 6-5
9-15
7-8 - 7-9
7-4
7-11 - 7-12
9-15 - 9-16
7-11 - 7-12
5-2 - 5-3
7-11 - 7-12
7-11 - 7-12
9-15
9-15
9-15
9-16
9-14
9-18
9-9 - 9-10
9-17
9-17
6-11 - 6-12
9-15
9-15
11-5 - 11-7
9-17 - 9-18
9-17 - 9-18
9-16
9-16
9-13 - 9-18
9-7
9-16
10-6
10-8
10-29
1-1 - 1-4
1-2 - 1-3
1-2 - 1-3
1-2 - 1-3
1-3 - 1-4
1-2 - 1-3
5-1 - 5-2
1-9
11-1 - 11-2
10-14 - 10-16
10-1 - 10-3
10-14
P
P verb
Paging
Parenthetical options
Password
Perform account save or file-save and restore
Peripheral device
Physical item structure
Physical map of disk
Overflow area
POINTER-FILE file
POKE verb
Position tape
Advance to end-of -data
Erase selected tape drives
Forward tape
Move to specified file
Read tape labels
Retension tape
Rewind tape
Unload tape
Write end-of-file mark
Print banner option
Print file
Statuses
Print files
Print hold file on screen
Print to auxiliary port option
Printer administration
Check status of printers
Configure printers
Restart failed printer
Starting spooler
Stop printers
Printer adminstration
PRINT-ERR verb
Printers
Privilege level
Proc
Process settings
Type-ahead buffer
Process size limits
Processes and lines
ACQUIRE-LINE verb
CONVERSE verb
LINE-ATT verb
Index
6-15
2-9
6-11 - 6-12
4-5
10-14 - 10-15
1-9
5-4
5-1 - 5-2
5-1 - 5-2
8-12
8-3
10-10 - 10-13, 10-24 - 10-27
10-26
10-27
10-24 - 10-25
10-25
10-25
10-27
10-24
10-26
10-26
9-15
9-20 - 9-21
9-4 - 9-5
9-28
9-15
9-9 - 9-11
9-7 - 9-9
9-9
9-6 - 9-7
9-11 - 9-12
9-6 - 9-12
6-17
9-2 - 9-4
4-6
2-12
6-6 - 6-7
6-7
15-12 - 15-13
5-7 - 5-11
5-8
5-8
5-8
Index-xvii
Processes and lines (Continued)
LINE-DET verb
LINE-PROTOCOL verb
LINE-STATUS verb
LINK-LINE verb
LIST-ACQUIRED-LINE verb
LISTDEV verb
LISTPRO verb
PROCESS-STATUS verb
RELEASE-LINE verb
UNLINK-LINE verb
Processors
BASIC
ED
PROC
UCL
VISION
PROCESS-STATUS verb
Procs
Production verbs
Perform account-save or file-save and restore
Read and write print records using UniVision BASIC
Read and write spooler print files
Read and write using VISION verbs
PROTOCOL verb
Options
pse.conf file
Set up
5-8
5-8
5-8
5-8
5-8
5-8
5-8
5-8
5-8
5-8
1-6
1-6
1-6
1-6
1-6
5-8, 11-2
6-17 - 6-18
10-14 - 10-15
10-15 - 10-16
10-15
10-15
11-2, 11-5 - 11-7
11-5 - 11-7
15-4 - 15-5
Q
Q-pointers
Creation
Set up
QSELECT verb
7-14 - 7-15
15-12
6-17
R
R option
RAM
Read and write print records using UniVision BASIC
Read and write spooler print files
Read and write using VISION verbs
READ hooks
Read tape labels
READNEXT hooks
Reallocating files
Index-xviii
9-17 - 9-18
1-9
10-15 - 10-16
10-15
10-15
13-2
10-25
13-4
7-24 - 7-25
Reallocation
Reassign print files option
Receive system messages
Re-enable triggers
Reference other processes
Release acquired lines
RELEASE-LINE verb
Remote files in UniVision
Remote paths
Set up
Remove printer from system
Remove triggers
RENAME verb
Replace text
RESET-ITEM-LOCKS verb
RESET-PROCESS verb
Restart failed printer
Restart stopped printer
Restoration
Restore items from tape
Restrict access to UCL
Restrict user access
Retain print files as hold files
Retension tape
Retrieval codes
Retrieve item
Retrieve items
Return values
Rewind tape
Right-justified B+Tree index
RTD verb
4-7
4-11
9-17 - 9-18
6-3
13-9 - 13-10
6-19
11-12
5-8, 11-2, 11-12
15-13
15-7 - 15-11
9-22 - 9-23
13-10 - 13-11
6-17, 7-1
6-21 - 6-22
8-4
8-2
9-9
9-9
7-26
10-7 - 10-9, 10-28
6-2 - 6-3
6-2
9-22
10-27
7-17 - 7-19
4-5
4-10
6-24
5-6 - 5-7
13-5 - 13-6
10-24
12-6
6-16
S
S option
SAVE verb
SECURITY-LOG file
Select filename
Select hold files
Select job priority option
Select modulo
Select multiple tape drives
Select tape drive
List current tape device assignments
Select tape drive for account
Set tape drive assignments
Index
9-16
8-5
8-12
3-3
9-29
9-16
3-3 - 3-4
10-21
10-19 - 10-21
10-19 - 10-20
10-20 - 10-21
10-19
Index-xix
Select tape drive for account
Select multiple tape drives
SEL-RESTORE verb
Send hold file to tape
Server control commands
SERVER-STATUS verb
Set line and process characteristics
Communications line settings
List line and process characteristics
Process settings
Terminal and printer output settings
Set line characteristics and protocols
Set stacker options
Set tape drive assignments
Set time and date commands
Set up distributed filing system
Set up pse.conf file
Set up remote and local paths
Set up required Q-pointers
Set up TCP/IP network
Hosts table
Test IP connections
SET-DATE-EUR verb
SET-DATE-STD verb
SET-FILE verb
SET-TAPE verb
SET-TERM verb
SLEEP verb
SP-ASSIGN options
?
A
B
Destination
F
Forms queue
H
I
List assignment status
O
Open
Print banner
Print to auxiliary port
R
Reassign print files
Select job priority
SP-ASSIGN verb
Options
SP-CLOSE verb
SP-COPIES verb
Index-xx
10-20 - 10-21
10-21
7-26
9-31
8-5
8-5
6-5 - 6-10
6-5 - 6-6
6-7
6-6 - 6-7
6-8 - 6-10
11-3 - 11-7
6-25
10-19
8-2
15-1 - 15-17
15-4 - 15-5
15-7 - 15-11
15-12
15-2 - 15-5
15-3 - 15-4
15-4 - 15-5
15-5
8-2
8-2
7-15 - 7-16
8-3, 10-19
8-3
6-15
9-13 - 9-18
9-14
9-15
9-15
9-15 - 9-16
9-15
9-15
9-15
9-16
9-14
9-17
9-17
9-15
9-15
9-17 - 9-18
9-17 - 9-18
9-16
9-5, 9-13 - 9-18
9-13 - 9-18
9-5
9-5, 9-30
Special operator accounts
FILE-SAVE
STARTUP
Specify tape drive format
SP-EDIT verb
SP-ENABLE verb
SP-KILL verb
Spool hold file
Spool multiple hold files
Spooler
Basic operation
Spooler features
Summary
Spooler verb input conversions
SP-OPEN verb
SP-STATUS verb
SP-TAPEOUT verb
Stacker
Append text
Choose command to modify
Delete statements from stack
Edit stack
Enable
Execute previous statements
List stack
Modify previous statements
Reference other processes
Replace text
Retrieve item
Set stacker options
Store series of statements
Stacker commands
.A
.C
.E
.G
.K
.L
.M
.MU
.O
.P
.Q
.R
.S
.U
.X
.Z
STACK-OFF verb
STACK-ON verb
Index
8-8
8-8
8-8
10-22
9-5, 9-23 - 9-30
9-5, 9-9
9-5, 9-21 - 9-23
9-28
9-30
1-9, 9-1 - 9-35
9-1 - 9-6
9-6
9-34 - 9-35
9-5
9-5
9-6, 9-31 - 9-32
2-10 - 2-11, 6-18 - 6-25
6-22
6-21
6-24
6-21
6-19
6-20
6-19 - 6-20
6-20 - 6-22
6-19
6-21 - 6-22
6-24
6-25
6-22 - 6-24
6-22
6-22 - 6-24
6-21
6-21
6-24
2-10 - 2-11, 6-19 - 6-20
6-21 - 6-22
6-21 - 6-22
6-25
6-25
6-25
6-24
6-25
6-25
2-10 - 2-11, 6-20
6-25
6-16
6-16
Index-xxi
Start server on remote machine
Starting spooler
STARTPTR verb
Options
Start-up and shutdown commands
STARTUP verb
STAT-FILE file
Static hashed files
Statuses of print file
Stop printers
STOPPTR verb
Store series of statements
Stored format and output format
Date format
Format date
Format dollar amounts
Format time
Time format
STORE-PATHS file
Structure
Structure of data
Structure of items
Controlling and dependent specifications
Multi-valued attributes
SUBD verb
SUBX verb
Summary of spooler features
SYSPROG account
Access to SYSPROG account
Contents
SYSPROG commands
Account management
Copy
Miscellaneous
Server control
Set time and date
Start-up and shutdown
System backup
System maintenance and control
System monitoring
System restoration
SYSPROG verbs
:AUTHORISE
:INIT-TAPE
:INIT-DISK
:INIT-SYSTEM
:FILELOAD
:STARTSPOOLER
Index-xxii
15-12
9-6 - 9-7
9-5, 9-7 - 9-9
9-7
8-2
8-2
8-12
12-1
9-20 - 9-21
9-11 - 9-12
9-6, 9-11 - 9-12
6-22 - 6-24
4-21 - 4-23
4-23
4-22 - 4-23
4-23
4-22 - 4-23
4-23
4-23
8-12
4-14
1-3 - 1-4
4-16 - 4-21
4-20 - 4-21
4-17 - 4-20
6-16
6-16
9-6
8-1 - 8-2
8-1 - 8-2
8-2
8-2 - 8-5
8-3
8-5 - 8-6
8-5
8-5
8-2
8-2
8-5
8-3 - 8-4
8-4
8-5
8-3
8-4
8-4
8-4
8-5
8-3, 9-5 - 9-7
SYSPROG verbs (Continued)
:STOP-MASTER-SERVER
<<
>>
ACCOUNT-RESTORE
ACCOUNT-SAVE
ADD-ACCOUNTS
AUTO-LOGOFF
BUILD-LOCK-XREF
BUILD-TR-INDEX
CLEAR-GROUP-LOCKS
COMPARE
CREATE-ACCOUNT
DEFINE-CURSOR
DELETE-ACCOUNT
DUMP
FILE-SAVE
IDATE
LIST-FILE-STATS
LIST-SECURITY-LOG
LIST-TR-INDEX
LOCKOUT
LOCKOUT-STATUS
MAXUSERS
MODEM-OFF
MODEM-ON
POKE
RESET-ITEM-LOCKS
RESET-PROCESS
SAVE
SERVER-STATUS
SET-DATE-EUR
SET-DATE-STD
SET-TAPE
SET-TERM
STARTUP
TANDEM
UDATE
System backup commands
SYSTEM dictionary
Message items
Special operator accounts
System level files
User IDs
System hierarchy
System level files
ACC
BLOCK-CONVERT
DEVICE-DETAILS
Index
8-5
6-15, 8-5
6-15, 8-5
8-5
7-26, 8-5
8-5
6-4 - 6-5, 8-3
8-4
8-4
8-4
8-5
8-3, 8-6
8-4
8-3, 8-6
5-2 - 5-3, 6-15, 8-4
8-5
8-2
8-4
8-3
8-4
8-3
8-3
8-3
8-3
8-3
8-3
8-4
8-2
8-5
8-5
8-2
8-2
8-3, 10-19
8-3
8-2
8-3
8-2
8-5
1-9, 4-3, 8-8 - 8-12
8-8
8-9 - 8-10
8-8
8-10 - 8-12
8-8
1-2 - 1-3
8-10 - 8-12
8-10
8-11
8-11
Index-xxiii
System level files (Continued)
DEVICE-ERRORS
DEVICE-NAMES
ERRMSG
GROUP-LOCKS
ITEM-LOCKS
LOCKS-XREF
NEWAC
POINTER-FILE
SECURITY-LOG
STAT-FILE
STORE-PATHS
UV.HELP
UVPROCS
UVPROGS
System maintenance and control commands
System monitoring commands
System overview
System restoration commands
System software
Managing files
Managing users
Process scheduling
Processors
8-11
8-11
8-11, 8-13 - 8-15
8-11
8-11
8-12
8-12
8-12
8-12
8-12
8-12
8-12
8-12
8-12
8-3 - 8-4
8-4
1-1 - 1-9
8-5
1-4 - 1-7
1-6 - 1-7
1-5 - 1-6
1-6
1-6
T
T option
Tag
TANDEM verb
Tape commands
Summary
Tape control
Tape label format
Tape layout
Block size
Tape label format
T-ATT verb
TCP/IP network
Hosts table
Set up
Test IP connections
T-DET verb
T-DUMP verb
Options
T-EOD verb
T-ERASE verb
Index-xxiv
9-16
4-14
8-3
10-13 - 10-14
9-33 - 9-34
10-17
10-16 - 10-18
10-18
10-17
10-13, 10-22 - 10-23
15-3 - 15-4
15-2 - 15-5
15-4 - 15-5
15-5
10-13, 10-23
10-3, 10-5 - 10-7, 10-13, 10-27 - 10-28
10-6
10-2, 10-10, 10-13, 10-26
10-2, 10-13, 10-27
TERM verb
Terminal and printer output settings
TERM verb
Test file structure
Test IP connections
Test link
T-FORMAT verb
T-FWD verb
Time format
TIME verb
T-LOAD verb
Options
T-ONLINE verb
Transfer data between Pick-like systems
Transfer data to and from other systems
Transfer data between Pick-like systems
Transfer data to non-Pick-like system
Transfer data to non-Pick-like system
Block size
Use of print files
Translate data from another file
T-RDLBL verb
T-READ verb
Options
T-RET verb
T-REW verb
Trigger common area
Trigger hooks
DELETE
READ
READNEXT
WRITE
Triggers
Anatomy of trigger
Hooks
Troubleshooting magnetic tape
T-SELECT verb
T-SPACE verb
T-STATUS verb
T-UNLOAD verb
T-WEOF verb
T-WHAT verb
T-WTLBL verb
Type-ahead buffer
Types of index
Hash
Left-justified B+Tree
Right-justified B+Tree
Index
6-8 - 6-10, 6-15
6-8 - 6-10
6-8 - 6-10
7-20 - 7-22
15-5
15-13 - 15-14
10-13, 10-22
10-12, 10-13, 10-24 - 10-25
4-23
6-15
10-3, 10-8, 10-13, 10-28
10-8
10-2, 10-7 - 10-9, 10-13, 10-23 - 10-24
10-31
10-30 - 10-32
10-31
10-31 - 10-32
10-31 - 10-32
10-32
10-31 - 10-32
4-25
10-2, 10-12, 10-13, 10-25
10-2, 10-13, 10-29 - 10-30
10-29
10-2, 10-13, 10-27
10-2, 10-12, 10-13, 10-24
13-5
13-2 - 13-4
13-3 - 13-4
13-2
13-4
13-3
13-1 - 13-11
13-1 - 13-2
13-4 - 13-6
13-2 - 13-4
10-33
10-13, 10-20 - 10-21
10-2, 10-12, 10-14, 10-25
10-14, 10-19 - 10-20
10-14, 10-26
10-2, 10-14, 10-26
10-2, 10-14
10-2, 10-14
6-7
12-5
12-5
12-6
12-6
Index-xxv
U
UCL
UCL-I verbs
UCL-II verbs
UDATE verb
UniVision B+Trees
UniVision BASIC files
Creation
UniVision Control Language
BREAK key
Edit command line
Enter command
Paging
UniVision file system
Data files
Master dictionary
SYSTEM dictionary
Unlink and link lines
UNLINK-LINE verb
Unload tape
Update codes
Use Procs for printer control
Hold file retention
Tape control
Use Procs for tape control
Hold file retention
Tape control
Use spooler with tape drives
Copy print file from tape
Send hold file to tape
User account management
Account usage statistics
Create account
Delete account
User account verbs
ACQUIRE-LINE
ADDD
ADD-DELETE-TRIGGER
ADD-READNEXT-TRIGGER
ADD-READ-TRIGGER
ADD-WRITE-TRIGGER
ADDX
BLOCK-PRINT
BUILD-INDEX
CHARGES
Index-xxvi
1-9
6-15 - 6-16
6-16 - 6-17
8-2
12-3 - 12-4
7-6
2-5 - 2-10, 6-1 - 6-25
2-9 - 2-10
2-8 - 2-9
2-8
2-9
4-1 - 4-3
4-4
4-3
4-3
11-9
5-8, 11-2, 11-9
10-26
7-17 - 7-19
4-5
4-10
9-32 - 9-34
9-32 - 9-33
9-33 - 9-34
9-32 - 9-34
9-32 - 9-33
9-33 - 9-34
9-30 - 9-32
9-31 - 9-32
9-31
8-6 - 8-8
8-7 - 8-8
8-6
8-6
15-12
5-8, 11-2, 11-11
6-16
13-7
13-7 - 13-8
13-6 - 13-7
13-7
6-16
6-15
12-6
8-7 - 8-8
User account verbs (Continued)
CHARGE-TO
CLEAR-FILE
CONVERSE
COPY
CREATE-BFILE
CREATE-FILE
CREATE-INDEX
CT
DE
DEBUG-OFF
DEBUG-ON
DELETE
DELETE-FILE
DELETE-FILE\r
DELETE-INDEX
DISABLE-DELETE-TRIGGER
DISABLE-INDEX
DISABLE-READNEXT-TRIGGER
DISABLE-READ-TRIGGER
DISABLE-WRITE-TRIGGER
DIVD
DIVX
DOC-EDIT
DROP-DELETE-TRIGGER
DROP-READNEXT-TRIGGER
DROP-READ-TRIGGER
DROP-WRITE-TRIGGER
DTR
DTX
ECHO
ECHO-OFF
ECHO-ON
ED
EDIT
ENABLE-DELETE-TRIGGER
ENABLE-INDEX
ENABLE-READNEXT-TRIGGER
ENABLE-READ-TRIGGER
ENABLE-WRITE-TRIGGER
FILE-TEST
FIND
FORMAT
GROUP
HASH-TEST
ISTAT
ITEM
LINE-ATT
LINE-DET
LINE-PROTOCOL
Index
8-7 - 8-8
7-1, 7-6 - 7-7
5-8, 11-2, 11-12 - 11-17
6-17, 7-2, 7-8 - 7-11
7-6
3-4 - 3-5, 7-1
12-6
6-18
6-17, 7-11 - 7-12
6-16
6-16
7-2, 7-12 - 7-13
7-7 - 7-8
7-1
12-6
13-8
12-6
13-9
13-8
13-8
6-16
6-16
6-17, 7-11 - 7-12
13-11
13-11
13-10
13-10
6-16
6-16
6-15
6-16
6-16
6-17, 7-2, 7-11 - 7-12
6-17, 7-2, 7-11 - 7-12
13-9 - 13-10
12-6
13-10
13-9
13-9
7-20 - 7-22
6-17
10-13
6-17, 7-22 - 7-23
7-20 - 7-22
7-20
7-23 - 7-24
5-8, 11-2, 11-10
5-8, 11-2, 11-10 - 11-11
5-8, 11-2
Index-xxvii
LINE-STATUS
LINK-LINE
LISTABS
LIST-ACQUIRED-LINE
LISTCONN
LISTDEV
LISTDICT
LISTFILES
LIST-LINE-CHARS
LISTPEQS
LISTPRO
LISTPROCS
LISTPTR
LISTVERBS
LLC
MESSAGE
MOVE-FILE
MSG
MULD
MULX
NSELECT
P
PRINT-ERR
PROCESS-STATUS
PROTOCOL
QSELECT
RELEASE-LINE
RENAME
RTD
SEL-RESTORE
SET-FILE
SLEEP
SP-ASSIGN
SP-CLOSE
SP-COPIES
SP-EDIT
SP-ENABLE
SP-KILL
SP-OPEN
SP-STATUS
SP-TAPEOUT
STACK-OFF
STACK-ON
STARTPTR
STOPPTR
SUBD
SUBX
T-ATT
T-DET
Index-xxviii
5-8, 11-2
5-8, 11-2, 11-9
9-5
5-8, 11-2, 11-11 - 11-12
6-18
5-8
6-18
6-18
6-7, 11-2, 11-5
9-5, 9-18 - 9-21
5-8
6-18
9-5, 9-9 - 9-11
6-18
6-7, 11-5
6-15
7-1
6-15
6-16
6-16
6-17
6-15
6-17
5-8, 11-2
11-2, 11-5 - 11-7
6-17
5-8, 11-2, 11-12
6-17, 7-1
6-16
7-26
7-15 - 7-16
6-15
9-5, 9-13 - 9-18
9-5
9-5, 9-30
9-5, 9-23 - 9-30
9-5, 9-9
9-5, 9-21 - 9-23
9-5
9-5
9-6, 9-31 - 9-32
6-16
6-16
9-5, 9-7 - 9-9
9-6, 9-11 - 9-12
6-16
6-16
10-13, 10-22 - 10-23
10-13, 10-23
T-DUMP
T-EOD
T-ERASE
TERM
T-FORMAT
T-FWD
TIME
T-LOAD
T-ONLINE
T-RDLBL
T-READ
T-RET
T-REW
T-SELECT
T-SPACE
T-STATUS
T-UNLOAD
T-WEOF
T-WHAT
T-WTLBL
UNLINK-LINE
WHO
XTD
User accounts
User commands
Catalogued UniVision BASIC programs
Procs
Verbs
User IDs
User process
User process code
Using BASIC programs
UV.HELP file
UVPROCS file
UVPROGS file
10-3, 10-5 - 10-7, 10-13, 10-27 - 10-28
10-2, 10-10, 10-13, 10-26
10-2, 10-13, 10-27
6-8 - 6-10, 6-15
10-13, 10-22
10-12, 10-13, 10-24 - 10-25
6-15
10-3, 10-8, 10-13, 10-28
10-2, 10-7 - 10-9, 10-13, 10-23 - 10-24
10-2, 10-12, 10-13, 10-25
10-2, 10-13, 10-29 - 10-30
10-2, 10-13, 10-27
10-2, 10-12, 10-13, 10-24
10-13, 10-20 - 10-21
10-2, 10-12, 10-14, 10-25
10-14, 10-19 - 10-20
10-14, 10-26
10-2, 10-14, 10-26
10-2, 10-14
10-2, 10-14
5-8, 11-2, 11-9
6-15
6-16
2-1 - 2-19
6-10 - 6-18
6-18
6-17 - 6-18
6-11 - 6-17
8-8
1-9
4-7
11-13 - 11-17
8-12
8-12
8-12
V
Value
Verb format
Verb syntax
Verbs
:AUTHORISE
:INIT-TAPE
:INIT-DISK
:INIT-SYSTEM
1-9
2-12, 4-9
6-12 - 6-15
6-11
6-11 - 6-17
8-3
8-4
8-4
8-4
Index
Index-xxix
Verbs (Continued)
:FILELOAD
:STARTSPOOLER
:STOP-MASTER-SERVER
<<
>>
ACCOUNT-RESTORE
ACCOUNT-SAVE
ACQUIRE-LINE
ADD-ACCOUNTS
ADDD
ADD-DELETE-TRIGGER
ADD-READNEXT-TRIGGER
ADD-READ-TRIGGER
ADD-WRITE-TRIGGER
ADDX
AUTO-LOGOFF
BLOCK-PRINT
BUILD-INDEX
BUILD-LOCK-XREF
BUILD-TR-INDEX
CHARGES
CHARGE-TO
CLEAR-FILE
CLEAR-GROUP-LOCKS
COMPARE
CONVERSE
COPY
CREATE-ACCOUNT
CREATE-BFILE
CREATE-FILE
CREATE-INDEX
CT
DE
DEBUG-OFF
DEBUG-ON
DEFINE-CURSOR
DELETE
DELETE-ACCOUNT
DELETE-FILE
DELETE-INDEX
DISABLE-DELETE-TRIGGER
DISABLE-INDEX
DISABLE-READNEXT-TRIGGER
DISABLE-READ-TRIGGER
DISABLE-WRITE-TRIGGER
DIVD
DIVX
DOC-EDIT
Index-xxx
8-5
15-12
8-3, 9-5 - 9-7
8-5
6-15, 8-5
6-15, 8-5
7-26, 8-5
7-26, 8-5
5-8, 11-2, 11-11
8-5
6-16
13-7
13-7 - 13-8
13-6 - 13-7
13-7
6-16
6-4 - 6-5, 8-3
6-15
12-6
8-4
8-4
8-7 - 8-8
8-7 - 8-8
7-1, 7-6 - 7-7
8-4
8-5
5-8, 11-2, 11-12 - 11-17
6-17, 7-2, 7-8 - 7-11
8-3, 8-6
7-6
3-4 - 3-5, 7-1, 7-3 - 7-6
12-6
6-18
6-17, 7-11 - 7-12
6-16
6-16
8-4
7-2, 7-12 - 7-13
8-3, 8-6
7-1 - 7-2, 7-7 - 7-8
12-6
13-8
12-6
13-9
13-8
13-8
6-16
6-16
6-17, 7-11 - 7-12
Verbs (Continued)
DROP-DELETE-TRIGGER
DROP-READNEXT-TRIGGER
DROP-READ-TRIGGER
DROP-WRITE-TRIGGER
DTR
DTX
DUMP
ECHO
ECHO-OFF
ECHO-ON
ED
EDIT
ENABLE-DELETE-TRIGGER
ENABLE-INDEX
ENABLE-READNEXT-TRIGGER
ENABLE-READ-TRIGGER
ENABLE-WRITE-TRIGGER
FILE-SAVE
FILE-TEST
FIND
Format
FORMAT
GROUP
HASH-TEST
IDATEP
ISTAT
ITEM
LINE-ATT
LINE-DET
LINE-PROTOCOL
LINE-STATUS
LINK-LINE
LISTABS
LIST-ACQUIRED-LINE
LISTCONN
LISTDEV
LISTDICT
LISTFILES
LIST-FILE-STATS
LIST-LINE-CHARS
LISTPEQS
LISTPRO
LISTPROCS
LISTPTR
LIST-SECURITY-LOG
LIST-TR-INDEX
LISTVERBS
LLC
LOCKOUT
Index
13-11
13-11
13-10
13-10
6-16
6-16
5-2 - 5-3, 6-15, 8-4
6-15
6-16
6-16
6-17, 7-2, 7-11 - 7-12
6-17, 7-2, 7-11 - 7-12
13-9 - 13-10
12-6
13-10
13-9
13-9
8-5
7-20 - 7-22
6-17
6-12 - 6-15
10-13
6-17, 7-22 - 7-23
7-20 - 7-22
8-2
7-20
7-23 - 7-24
5-8, 11-2, 11-10
5-8, 11-2, 11-10 - 11-11
5-8, 11-2
5-8, 11-2
5-8, 11-2, 11-9
9-5
5-8, 11-2, 11-11 - 11-12
6-18
5-8
6-18
6-18
8-4
6-7, 11-2, 11-5
9-5, 9-18 - 9-21
5-8
6-18
9-5, 9-9 - 9-11
8-3
8-4
6-18
6-7, 11-5
8-3
Index-xxxi
Verbs (Continued)
LOCKOUT-STATUS
MAXUSERS
MESSAGE
MODEM-OFF
MODEM-ON
MOVE-FILE
MSG
MULD
MULX
NSELECT
P
Parenthetical options
POKE
PRINT-ERR
PROCESS-STATUS
PROTOCOL
QSELECT
RELEASE-LINE
RENAME
RESET-ITEM-LOCKS
RESET-PROCESS
RTD
SAVE
SEL-RESTORE
SERVER-STATUS
SET-DATE-EUR
SET-DATE-STD
SET-FILE
SET-TAPE
SET-TERM
SLEEP
SP-ASSIGN
SP-CLOSE
SP-COPIES
SP-EDIT
SP-ENABLE
SP-KILL
SP-OPEN
SP-STATUS
SP-TAPEOUT
STACK-OFF
STACK-ON
STARTPTR
STARTUP
STOPPTR
SUBD
SUBX
Syntax
TANDEM
Index-xxxii
8-3
8-3
6-15
8-3
8-3
7-1
6-15
6-16
6-16
6-17
6-15
6-11 - 6-12
8-3
6-17
5-8, 11-2
11-2, 11-5 - 11-7
6-17
5-8, 11-2, 11-12
6-17, 7-1
8-4
8-2
6-16
8-5
7-26
8-5
8-2
8-2
7-15 - 7-16
8-3, 10-19
8-3
6-15
9-5, 9-13 - 9-18
9-5
9-5, 9-30
9-5, 9-23 - 9-30
9-5, 9-9
9-5, 9-21 - 9-23
9-5
9-5
9-6, 9-31 - 9-32
6-16
6-16
9-5, 9-7 - 9-9
8-2
9-6, 9-11 - 9-12
6-16
6-16
6-11
8-3
Verbs (Continued)
T-ATT
T-DET
T-DUMP
T-EOD
T-ERASE
TERM
T-FORMAT
T-FWD
TIME
T-LOAD
T-ONLINE
T-RDLBL
T-READ
T-RET
T-REW
T-SELECT
T-SPACE
T-STATUS
T-UNLOAD
T-WEOF
T-WHAT
T-WTLBL
UCL-I
UCL-II
UDATE
UNLINK-LINE
VISION
WHO
XTD
View contents of hold file
Virtual file system handling
Virtual file system interface
External file handler link item format
Functional description
Introduction
Virtual memory
VISION keywords
VISION verbs
10-13, 10-22 - 10-23
10-13, 10-23
10-3, 10-5 - 10-7, 10-13, 10-27 - 10-28
10-2, 10-10, 10-13, 10-26
10-2, 10-13, 10-27
6-8 - 6-10, 6-15
10-13, 10-22
10-12, 10-13, 10-24 - 10-25
6-15
10-3, 10-8, 10-13, 10-28
10-2, 10-7 - 10-9, 10-13, 10-23 - 10-24
10-2, 10-12, 10-13, 10-25
10-2, 10-13, 10-29 - 10-30
10-2, 10-13, 10-27
10-2, 10-12, 10-13, 10-24
10-13, 10-20 - 10-21
10-2, 10-12, 10-14, 10-25
10-14, 10-19 - 10-20
10-14, 10-26
10-2, 10-14, 10-26
10-2, 10-14
10-2, 10-14
6-15 - 6-16
6-16 - 6-17
8-2
5-8, 11-2, 11-9
6-17
6-15
6-16
9-26
14-1 - 14-9
14-2 - 14-6
14-1 - 14-2
14-6 - 14-9
14-1 - 14-9
14-1
1-9
2-12
6-17
W
WHO verb
Width
Index
6-15
4-7
4-15
4-11
Index-xxxiii
Write and read tape
Access tape drive
Append data to tape
Dump file to tape
Position tape
Restore items from tape
Write end-of-file mark
WRITE hooks
10-3 - 10-13
10-3 - 10-5
10-10
10-5 - 10-7
10-10 - 10-13
10-7 - 10-9
10-26
13-3
X
XTD verb
Index-xxxiv
6-16

A Guide To The UniVision System

Transcription

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