HP OpenVMS Systems Documentation
OpenVMS User's Manual
interactive utility: A computer program, invoked with
a DCL command, that provides a special environment from which you can
perform a specific set of tasks. You work interactively with these
utilities by entering subcommands and other information in response to
the utility's prompt.
iterative translation: The repetitive translation of a
logical name that occurs when a logical name's definition includes
another logical name.
job: The accounting unit equivalent to a process and
its subprocesses, if any, and all subprocesses that they create. Jobs
are classified as batch and interactive. For example, the job
controller creates an interactive job to handle a user's requests when
the user logs in to the system and it creates a batch job when the
symbiont manager passes a command input file to it.
job tree: A hierarchy of all processes and
subprocesses, with the main process at the top.
key: One of the following:
keyboard: An input device that can be operated
similarly to a typewriter.
keypad: The small set of keys next to the main
keyboard on a terminal.
keyword: A word reserved for use in certain specified
syntax formats, usually in a command string or a statement.
lexical function: A command language construct that
the DIGITAL Command Language (DCL) command interpreter evaluates and
substitutes before it parses a command string. Lexical functions return
information about the current process (the user identification code
(UIC) or default directory, for example) and about character strings
(their length or the location of substrings, for example).
line editor: A program that allows you to make
additions and deletions to a file line by line.
line printer: An output device that prints files one
line at a time. It is used for printing large amounts of output that
would otherwise tie up a slower device. Almost every system has a
device designated as the line printer. In some cases, the "line
printer" is actually a high-speed terminal.
local node: The network node at which the user is
local symbol: Either of the following:
logging in: The identification of a user to the
system. When users log in, they type a user name and password in
response to prompts from the system. If the user name and the password
match an account on the system, the user is allowed access to the
logging out: The process of entering the DIGITAL
Command Language (DCL) command LOGOUT, which informs the operating
system that the user has finished using a particular terminal.
logical device name: A character string that equates a
somewhat cryptic device name to a short, meaningful name.
logical expression: An expression that has a true or
logical name: A user-specified name that can be used
in place of another character string to represent system objects such
as files, directories, devices, and queues. Logical name assignments
are maintained in logical name tables.
logical name table: A table that contains a set of
logical names and their equivalence strings. A logical name can be
process private or shareable. The default shareable logical name tables
are job, group, system, clusterwide system, and clusterwide parent
login class: User's method of logging in to the
system. System managers can control system access based on the login
class: local, dialup, remote, batch, or network.
login command procedure: A command procedure that is
automatically executed at login and at the beginning of a batch job.
login directory: The default directory established by
LOGINOUT when a user logs in.
magnetic tape: A medium on which data can be stored
mass storage device: An input/output device on which
data and other types of files are stored while they are not being used.
Typical mass storage devices include disks, magnetic tapes, and floppy
memory: A series of physical locations into which data
or instructions can be placed in the form of binary words. Each
location in memory can be addressed and its contents can be altered.
Memory should not be confused with mass storage devices.
Multipurpose Internet Mail Extension (MIME): The
standard used to attach nontext files to mail messages. Nontext files,
such as graphics or sound files, are encoded and sent as plain text,
although that text may not be readable. The recipient can decode the
text into the file's original format using a MIME interpreter utility.
network: A collection of interconnected, individual
node: One of the following:
node specification: The first field in a file
specification. This field identifies the location of a computer system
in a network.
null value: A string with no characters that is
represented in a command procedure by two quotation marks (" ").
numeric expression: A mathematical statement
consisting of a collection of operands connected by arithmetic
object: A passive repository of information to which
the system controls access. Access to an object implies access to the
information it contains.
open: The act of preparing a data set or file for
open account: An account that does not require a
operand: The part of an expression that contains a
value. Operands are acted on by operators during expression evaluation
to produce a result.
operating system: An integrated collection of programs
that controls the execution of computer programs and performs system
operator: The part of an expression that tells the
computer how to manipulate the operands. For example, the plus sign (+)
is an operator that tells the computer to perform addition.
output file: A file that contains the results of a
processing operation; for example, a file that has been sorted or
parameter: Either of the following:
parsing: Either of the following:
password: A character string that users provide at
login time to validate their identities and as a form of proof of their
authorization to access their accounts. There are two kinds of
passwords---system passwords and user passwords. User passwords include
both primary and secondary passwords.
physical device name: A character string that uniquely
identifies a physical device (such as a storage disk or a terminal) to
primary password: A type of user password that is the
first user password the system requests from the user. Systems may
optionally require a secondary password as well. The primary password
must be the password that is associated with the user name.
print form: A set of attributes that defines page set
up and stock for printing.
print queue: A list of files waiting to be printed.
priority: A rank assigned to a process to determine
its precedence in obtaining system resources when the process is
private volume: A mass storage media that has been
allocated by a process for its own exclusive use.
process: The basic entity scheduled by the system
software. A process provides the context in which an image executes. A
process consists of an address space and both hardware and software
program: A series of instructions aimed at a
particular result. Programming languages are a means of describing
procedures so that they can be performed by a computer. See also
program stub: A temporary section of code that is used
during the testing phase of writing command procedures. A program stub
usually outputs a message stating the procedure it is replacing.
prompt: A character string appearing on a terminal
screen indicating that the user must provide input.
protected object: An object containing shareable
information to which the system controls access. See also
protection code: A series of letters that specify what
access different categories of system users can have to a file or to
another protected object and what they can do to it when they access it.
proxy login: A type of login that permits a user from
a remote node to effectively log in to a local node as if the user
owned an account on the local node. However, the user does not specify
a password in the access control string. The remote user may own the
account or share the account with other users.
qualifier: A portion of a command string that modifies
a command verb or command parameter by selecting one of several
options. A qualifier, if present, follows the command verb or parameter
to which it applies and is in the format /qualifier[=option]. For
example, in the command string "PRINT filename /COPIES=3,"
the COPIES qualifier indicates that the user wants three copies of a
given file printed.
queue: Either of the following:
random access: A method for retrieving or writing data
in which the location of the data to be retrieved or written is not
dependent on the location of previously retrieved or written data.
Random access refers to memory or mass storage devices on which all
information is equally accessible.
read: The act or capability of an image to accept
data. For example, when a TYPE command is issued, the system reads the
designated file from disk and writes it to the terminal. See also
record file address (RFA): The unique address of a
record in a file. The RFA allows previously accessed records to be
accessed randomly at a subsequent time. This access occurs regardless
of the file organization.
Record Management Services (RMS): See RMS (Record
record-oriented device: A device such as a terminal,
line printer, or card reader. A record-oriented device's physical
record is the largest unit of data that a program can access in one I/O
record sorting: A sorting process in which records are
kept intact and an output file consisting of complete records is
relative file organization: The arrangement of records
in a file in which each record occupies a cell of equal length within a
bucket. Each cell is assigned a successive number, which represents its
position relative to the beginning of the file.
remote node: Any node in a network, other than the
node that you are currently logged in to.
restricted account: A type of OpenVMS account with a
secure login procedure. The user is not allowed to use the Ctrl/Y key
sequence during the system or process login command procedure. Control
may be turned over to the user following execution of the login command
reverse video: A feature of a video terminal that
reverses the default video contrast. If the default display is black
figures on a white background, reverse video displays white figures on
a black background.
RMS (Record Management Services): A set of operating
system procedures that are called by programs to process files and
records within files. RMS allows programs to issue GET and PUT requests
at the record level (record I/O) as well as read and write blocks
(block I/O). RMS is an integral part of the system software; its
procedures run in executive mode.
scrolling: A feature of a video terminal that allows
the display of more than one screen of text by vertical movement. For
example, when the TYPE command is entered, new output appears at the
bottom of the screen as the oldest output disappears off the top.
secondary password: A user password that may be
required at login time immediately after the primary password has been
submitted correctly. Primary and secondary passwords can be known by
separate users to ensure that more than one user is present at the
login. A less common use is to require a secondary password as a means
of increasing the password length so that the total number of
combinations of characters makes password guessing more time-consuming
secure terminal server: OpenVMS software designed to
ensure that users can log in only to terminals that are already logged
out. When the user presses the Break key on a terminal, the secure
terminal server (if enabled) responds by first disconnecting any
logged-in process and then initiating a login. If no process is logged
in at the terminal, the login can proceed immediately.
sequential access mode: The retrieval or storage of
records in which a program reads or writes records one after the other
in the order in which they appear, starting and ending at any arbitrary
point in the file.
sequential file organization: A file organization in
which records appear in the order in which they were originally
written. The records can be fixed or variable length. Records can be
accessed sequentially or randomly by record address. Fixed length
records can also be accessed randomly by relative record number.
software: The collection of images, procedures, rules,
and documentation associated with the operation of a particular
computer system. For example, the operating system is software.
specification file: A command file used in the
Sort/Merge utility to specify the commands and qualifiers needed to
complete a sort operation.
string: A connected sequence of characters. When a
text editor searches for a word or phrase in a text file, it is looking
for a string. The character sequence that forms a command is often
called a command string.
subdirectory: A directory file, cataloged in a higher
level directory, that lists additional files belonging to the owner of
subprocess: A subsidiary process created by another
process. The process that creates a subprocess is its owner. A process
and its subprocesses share a pool of quotas and limits. When an owner
process is removed from the system, all its subprocesses (and their
subprocesses) are also removed.
subroutine: A subsidiary routine that executes when
called by another program. A subroutine is often called repeatedly
until a certain condition is met.
symbol: An entity that, when defined, represents a
particular function or entity (for example, a command string, directory
name, or file name) in a particular context.
symbol scope: The set of command procedure levels from
within which the symbol can be accessed.
syntax: The particular form of a command, including
the spelling and the order of qualifiers and parameters. Misspelled
words are the most common syntax errors.
system manager: The person who makes resources
available to users and sets up restrictions governing the use of such
system password: A password required by a terminal
before login can be initiated.
terminal: The general name for a peripheral device
that has a keyboard and a video screen or printer. Under program
control, a terminal enables users to type commands and data from the
keyboard and receive messages on the video screen or printer. Examples
of terminals are the LA36 DECwriter hardcopy terminal, the VT100 video
display terminal, and the VT240 series video terminal.
timeout: The expiration of the time limit during which
a device is to complete an I/O transfer.
time-stamp: A text string that fully specifies a data
and time. For example, 11-DEC-1996 17:13:21.
UAF (user authorization file): The file that holds
details of each account on the system. The UAF contains the user name,
password, user identification code (UIC), quotas, limits, and
privileges assigned to each account.
UFD (user file directory): A file that briefly
catalogs a set of files stored on disk or tape. The UFD includes the
name, type, and version number of each file in the set. It also
contains a unique number that identifies that file's actual location
and points to a list of its file attributes. See also
UIC (user identification code): The pair of numbers
assigned to users, files, global sections, command event flag clusters,
and mailboxes. The UIC specifies the type of access (read, write, or
read/write, and in the case of files, execute, delete, or both)
available to the owner, group, world, and system.
user authorization file (UAF): See UAF (user
user password: A password that is associated with a
user. This password must be correctly supplied when the user attempts
to log in so that the user is approved for access to the system. The
two types of user passwords are primary and secondary; the terms also
represent the sequence in which they are entered.
utility: A program that provides a set of related
general-purpose functions, such as a program development utility (an
editor, a linker), a file management utility (file copy or file format
translation program), or an operations management utility (disk quotas,
version number: The numeric component of a file
specification. When a file is edited, its version number is increased
video terminal: A terminal with a video screen for
accepting output. See also terminal.
volume: A mass storage media such as a disk pack or
reel of magnetic tape. The volume is the largest logical unit of the
volume set: The file-structured collection of data
residing on one or more mass storage media.
wildcard character: A nonalphanumeric character such
as an asterisk (*) or percent sign (%) that is used within, or in place
of, a file name, a file type, a directory name, or a version number in
a file specification to indicate "all" for the given field.
write: The act or capability of an image to send data. For example, when a PRINT command is issued, the specified file is read from wherever it is stored and is written to the printer. See also read.