This glossary provides definitions for many of the terms you may see while using the Tru64 UNIX documentation. Although the majority of terms deal with the UNIX environment, you will also find other common terms you will encounter; for example, words related to the Internet.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
Special Characters
See root
A shorthand expression representing the user's working directory.
See also working directory
A shorthand expression representing the immediate parent of the user's working directory.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
A pathname that begins at the root directory; a pathname that
always begins with a slash (/).
For example,
/usr/games
is an absolute pathname.
Also called a full pathname.
See also relative pathname
In an XTI transport connection, the transport user that initiated the connection.
See also client process, passive user, XTI (X/Open Transport Interface)
A name or symbol used in place of another name, symbol, or
group of symbols; usually shorter or easier to use than what it represents.
For example, if you often access a certain directory, you could set up an
alias so that the word
work
would be an alias for
"cd /share/tomb/tools/tools/work".
Thereafter, typing
work
would put you in the
/share/tomb/tools/tools/work
directory.
For more information see the
alias(1)
reference page.
A method prescribed by a specific program (application) or by the computer operating system by which a programmer writing an application program can make requests of the specific program or the operating system.
A program or set of programs designed to perform a particular useful function or set of functions; for example, the Source Code Control System (SCCS) is an application for managing program source code.
A command that displays the reference page names and summary
lines that contain a specified word or string of characters.
The
apropos
command is the same as the
man -k
command.
See also reference page, man
1. To store programs, data files, text files, and other types of files for safekeeping.
2. A repository for such files.
The number of arguments passed by a command interpreter to a command, or from a routine in a program to a subroutine, procedure, or function.
The actual information (arguments) passed by a command interpreter to a command, or from a routine in a program to a subroutine, procedure, or function.
1. The Internet (TCP/IP) Protocol that can dynamically bind a high-level Internet address to a low-level, physical hardware address. ARP can be used only across a single physical network and in networks that support the hardware broadcast feature.
2. The Internet (TCP/IP) Protocol that dynamically maps between Internet addresses, Baseband Adapter addresses, and Token-Ring Adapter addresses on a local area network (LAN).
A collection of data elements (variables) identified by a common name and distinguished from one another by numbers representing their positions in the collection. The distinguishing numbers are called subscripts.
A statement that sets a value for a particular field or parameter. In program source files and scripts, assignment statements often have the form parameter=value.
A standard character set that defines 128 characters (including control and graphic characters). ASCII (American Standard Code for Information Interchange) assigns a 7-bit binary value to each letter, number, and selected control character. The terms ASCII file and text file are used interchangeably.
See event
1. The execution of processes or threads in which each process or thread does not await the completion of the others before starting.
2. In XTI, a mode of execution that notifies the transport user of an event without forcing it to wait.
A 25 M/bps to 622 M/bps network standard that uses cell switching. It is connection oriented, providing switched, full-duplex communication circuits between nodes.
In the key file of a software product kit, a line specifying
the name and value for a single attribute of the kit.
Controls how the kit
is built by the
kits
command and how it is installed by
the
setld
utility.
The command for executing programs written in the
awk
programming language.
An
awk
program is a
sequence of patterns and corresponding actions that are carried out when a
pattern is read.
The
awk
utility is a more powerful tool
for pattern matching and text manipulation than either
grep
or
sed.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
B
A job that runs without interfering with normal command-line
entries.
A process runs in the background when the command to begin the process
is entered with an ampersand (&) character following it.
For example,
to run the X Window System clock program in background, a user would enter
the command
xclock &.
As a result, the clock would
be invoked in one window, while the command line on which the
xclock
command was entered would be ready to accept new commands.
See also foreground process
A directory that contains executable programs and scripts.
For example, the
/usr/bin
directory contains programs that
nonprivileged users can run, and the
/sbin
directory contains
programs that only privileged users can run.
See also binary file, path, script
1. Referring to the number 2 or the system of binary numeration.
2. Referring to an executable file created by a compilation process.
3. Referring to a situation that can assume one of two possible states.
A file created by a compilation process.
Binary files contain
codes that are not part of the
ASCII
character
set and utilize all 256 possible byte values.
Binary files cannot be read
using programs such as
more, nor can they be edited using
editors such as
vi.
See also text file
1. A symbol that represents an operation to be performed on two arrays, data items, or expressions. The four types of binary operators are character, logical, numeric, and relational.
2. An arithmetic operator that has two terms.
A name service available on internet networks.
A term for any receptacle into which data is placed without
the possibility of retrieval.
It is often used to refer to the null device
/dev/null.
A data storage or transfer device that manipulates data in groups of a fixed size; for example, a disk, whose data storage size is usually 512 bytes.
See also character device
The method used by the Tru64 UNIX operating system to select the entry points associated with a particular block device.
See also character device switch table
A device special file that provides access to an input or output device and is capable of supporting a file system.
See also device special file
1. An algebra (named for George Boole) that is similar in form to ordinary algebra, but in which the values of the variables are restricted to the two possible values true and false. The logic of Boolean algebra works well with the binary logic of computers, where values are represented by the digits 0 and 1.
2. A term sometimes used to refer to Boolean operators, including AND, OR, NOT, EXCEPT, IF, THEN, TRUE, and FALSE.
The command interpreter and interpreted programming language originally developed by Steve Bourne.
See also shell
A place in a source code program that stops the debugger during program execution. Breakpoints aid in the testing and debugging of programs.
See also tracepoint
In a programming language, a statement that causes the program to exit immediately from the current control structure (such as a case statement or a for loop). A break statement is often used to terminate execution of a loop before the programmed number of iterations has been performed.
The UNIX software release of the Computer System Research Group of the University of California at Berkeley -- the basis for some features of the Tru64 UNIX operating system.
A transport-layer interface provided for applications to perform interprocess communication between two unrelated processes on a single system or on multiple connected systems. This interprocess communications facility allows programs to use sockets for communications between other programs, protocols, and devices.
A command that is built into a shell, as opposed to a command that stands alone as a separate executable file and is invoked by a shell.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
A structured, procedural programming language that is widely used both for operating systems and applications and that has a wide following in colleges and universities. The Tru64 UNIX operating system is written in C, which has been standardized as part of the Portable Operating System Interface (POSIX).
An object-oriented programming language that is now generally viewed as the best language for creating large-scale application programs. C++ (pronounced C plus plus) is a superset of the C programming language.
In a programming language, a statement that invokes a subroutine, function, or procedure.
In a programming language, a method of passing an argument to a subroutine, a function, or a procedure by supplying the address of the data rather than its actual value.
See also call by value
In a programming language, a method of passing an argument to a subroutine, a function, or a procedure by supplying the actual value of the data.
See also call by reference
The ANSI standard that defines the software interface between device drivers and the Host Bus Adapters, as well as other means by which SCSI peripherals are attached to a host processor.
A character that forces all following text to the left margin of the next line or that signals the end of user input. The Return key is usually used to produce a carriage return.
Unable to distinguish between uppercase and lowercase letters.
A case-insensitive device or program considers
A
and
a
to be the same character.
See also case sensitive
Able to distinguish between uppercase and lowercase letters.
A case sensitive device or program considers
A
and
a
to be different characters.
Devices and programs that are part
of the Tru64 UNIX operating system are case sensitive.
See also case insensitive
In a programming language, a control structure that can take any of several possible paths depending on the evaluation of its argument.
A terminal driver operation mode that allows processes to read input as it is being typed. This mode eliminates the character, mode, and line editing input facilities.
The data structure provided by SCSI peripheral drivers to the XPT transport level to control the execution of a function by the SCSI Interface Module (SIM).
A data structure that contains the SCSI operation code, parameters, and control bits for a specific operation.
A graphical user interface for interacting with the Tru64 UNIX operating system. The CDE interface was jointly developed and is based on industry standards, including the X Consortium's X Window System and the Open Software Foundation's Motif interface.
A data storage or transfer device that manipulates data in increments of a single character; for example, a terminal.
See also block device
The method used by the Tru64 UNIX operating system to select the entry points associated with a particular character device.
See also block device switch table
A file through which processes can access either a character-stream oriented I/O interface or an unstructured (raw) device, such as a communication line or an unbuffered magnetic tape or disk.
See parent process
A computer system that uses resources provided by another computer system called a server.
In the client/server model of communication, a process that requests services from a server process.
A data structure used by a BSD-type of terminal driver to store data coming from, or going to, terminals.
See also STREAMS
See history list
A program that understands and executes programs written in a particular source language. Interpreted programs execute more slowly than compiled programs because the interpreter is performing two operations at once.
Perl and JavaScript are examples of popular scripting languages that rely on command interpreters. The UNIX shells are command interpreters.
See shell
A state of a system or device in which the user can enter commands.
The ability to capture the output of any command as an argument
to another command by placing that command line within grave accents ( `
` ).
The shell first executes the
command or commands enclosed within the grave accents and then replaces the
whole expression, including grave accents, with their output.
This feature
is often used in assignment statements.
To selectively disable interpretation of a portion of a program or document source file.
On internet networks, the decimal for the 32-bit internet address. Also called dotted-decimal notation.
An abstraction used by the interprocess communication facility of a system to define the properties of a network. Properties include a set of communication protocols, rules for manipulating and interpreting names, and the ability to transmit access rights.
To process one or more program source files in order to produce an executable binary file or an object file.
A program that translates programs written in a particular
source language into executable binary files (or into intermediate binary
files referred to as object files).
The input can include one or more source-language
files together with one or more object files.
Compiled programs execute faster
than interpreted programs because the compiler has already performed the interpretation.
The
cc
program is a C compiler.
See also binary file, compile, command interpreter, object file
Refers to actions that are taken by a compiler during the compilation of a program.
See also run time
See virus
See worm
To place together. Data elements such as strings can be concatenated to produce a string that contains all of the characters of the first original string, followed by the characters of the next original string, and so on. Files can be concatenated by combining their contents in a similar manner, either into a new file or into one of the original files.
During the compilation of a program, a portion of the process (code block) that is enabled or disabled by a variable or condition external to the code block under consideration. For example, a certain program might contain a block that is to be compiled only if the compilation is performed on a Tru64 UNIX system.
During the execution of a program, a portion of the program's behavior or output that is enabled or disabled by a variable or condition. For example, a certain program might contain code that asks the user questions only if the user initiates the program to run in a menu mode.
In a programming language, a statement (for example, the if statement) that evaluates one or more variables or conditions and uses the result to choose one of several possible paths through the subsequent code.
1. The machines, devices, and programs that make up a data processing system or network.
2. The act of making a subsystem, or a set of subsystems, available for use by a running operating system.
3. The set of configured subsystems in an operating system.
A file that specifies the characteristics of a system or subsystem.
A mode of service supported by a transport endpoint that requires no established connection for transmitting data. Data is delivered in self-contained units, called datagrams.
A mode of service supported by a transport endpoint for transmitting data over an established connection.
A data structure used for a particular purpose.
See global search
In a programming language, a statement that can cause different actions to ensue, depending on the results of an evaluation or test.
The condition of a device driver in which the driver interprets the data passing through it. For example, a UNIX terminal driver operating in cooked mode translates a Return character from the terminal into a Line Feed character to be passed to the system.
See also raw mode
A daemon that executes commands at specified times and dates,
according to instructions in the
crontab
file.
See also daemon
A file that specifies the dates and times at which specified
commands are to be executed.
The
cron
daemon examines the
crontab
file at specified intervals, and executes the indicated
commands at the specified dates and times.
A command interpreter and interpreted programming language developed at the University of California at Berkeley; so named because many of its constructs resemble the equivalent C language constructs.
See also shell
For video display screens, a symbol that shows the location of keyboard input. The cursor shows the position at which the next character to be displayed will be placed.
See also pointer
A set of keys, usually labeled with arrows pointing up, down, left, and right, that position the cursor on a video display screen.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
A process that performs a system management function that
is transparent to the user.
A daemon can perform its task automatically or
periodically.
For example, the
cron
daemon periodically
performs the tasks listed in the
crontab
file.
Daemons
can be generated by the system and by applications.
Some daemons can also
be started manually; for example, the
binlogd
command starts
a daemon that logs binary event records to specified files.
The commands that
manually start daemons usually end with a
d.
The transmission of information between computers by means of a network such as an Ethernet, a telephone system, or a satellite link.
A unit of data that is transmitted across a network by the connectionless service of a transport provider. In addition to user data, a datagram includes the information needed for its delivery. It is self-contained, in that it has no relationship to any datagrams previously or subsequently transmitted.
A socket that provides datagrams consisting of individual messages for transmission in connectionless mode.
The command that invokes the
dbx
program,
which is used by developers to help debug other programs under development.
A de facto standard for distributed computing that defines a uniform set of services that share certain global properties for common naming, security, time synchronization, system availability, access to data, and system management. DCE enables applications and data on heterogeneous systems to work together.
In an RCS or SCCS file, the set of changes that constitute a specific version of the file.
See dependent
The condition in which a subset may or may not require the
presence of other subsets in order to function properly.
Evaluated by a subset's
software control program (SCP) under control of the
setld
utility.
See also SCP (Subset Control Program), subset
Also called a
dependency file.
In the
make
utility, an entity on which a file to be built
(the target) depends.
A source file is a dependent of an object module.
A job that continues processing after the user has logged out.
The software that controls a peripheral device such as a disk or a printer.
A file used by processes to access hardware devices. For example, a printer is accessed through a device special file.
See also block special file
A distributed DCE application that provides a unified, globally distributed file system. Under this file system, a DFS file is accessible from any DCE DFS machine using the same name, regardless of the server currently storing the file.
An Internet (TCP/IP) Protocol that enables the automatic assignment of Internet addresses to clients on the network from a pool of reusable addresses. Address assignment occurs automatically whenever client systems such as portable computers are attached to the network.
A type of file containing the names and controlling information for other files or other directories.
The arrangement of directories in a file system. The root directory is at the top of the directory hierarchy and contains pointers to all file systems and all directories on the system.
A data structure that stores directories for later recall.
The disk information, usually located in sector 0 (zero), that includes the disk geometry and partition divisions. This information is used by the system disk driver and the boot program to identify a drive, and to determine how to program a drive and where to find the file systems.
See partition
A service provided by Compaqwhereby a server computer
system maintains the
root,
/usr, and
/var
file systems for client computer systems connected to the server
via a local area network (LAN).
A reserved disk area that is physically connected to a DMS server and that contains multiple copies of the DMS root area, one for each DMS client.
A computer system whose system disk area is physically connected to a DMS server rather than to the client itself and is accessed across the network by the client.
A tree-structured system for organizing hosts names for an entire internet.
The period during which a machine is unavailable for use.
See also up time
A utility included in a patch kit that installs, removes, and manages patches for Tru64 UNIX and the TruCluster products. This utility is installed and left on the system through the successful installation of a Tru64 UNIX patch kit.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
E
A line-oriented program for modifying the contents of text
files.
The program operates by accepting commands from the user; for example,
issuing the command
s/Unix/UNIX/g
would cause the editor
to replace each instance of the string "Unix" on the current line
with "UNIX."
A program for modifying the contents of text files.
Full-screen
editors, such as
vi,
use video display terminals to display
several lines of the file being manipulated; they allow the user to move the
cursor to a specific location and change the text there.
Line editors, such
as
ed,
work on a line-by-line basis.
Stream editors, such
as
sed,
work by applying commands from a previously prepared
list (called a script) instead of by accepting commands from the user.
The point where a system starts when searching for a file. Its pathname begins with a slash (/).
The current user ID, but not necessarily the user's ID. For example, a user logged in under a login ID may change to another user's ID. The ID to which the user changes becomes the effective user ID until the user switches back to the original login ID.
A type of routing protocol that allows individual networks to communicate with the Internet backbone.
See also Internet
A text editor developed by the Free Software Foundation that is available for all UNIX systems, although it is not a standard part of Berkeley UNIX or System V. It is included with the Tru64 UNIX operating system.
A system that allows the exchange of written messages with other users over a network.
The set of conditions under which a user is working on the computer. The environment includes such information as the name of the working directory, the name of the command interpreter, the identity of the user's terminal, and so on.
A symbol containing information that can be used by shells or commands. Environment variables are available to all processes in a given process group; they are propagated by the creation of a child process.
See also process variable
1. A condition indicating that the end of a data file has been reached by a program reading the file.
2. A specific sequence of characters written on a magnetic tape.
See also file mark
A grouping of characters or character strings that are considered equal for purposes of collation. For example, many languages place an uppercase character in the same equivalence class as its lowercase form, but some languages distinguish between accented and unaccented character forms for the purpose of collation.
Any condition in which the expected results of an operation are not achieved. In XTI, an indicator that is returned by a function when it encounters a system or library error in the process of executing. The object is to allow applications to take an action based on the returned error code.
1. To protect a character from interpretation by a program by preceding it with a backslash (\).
2. An ASCII character that is usually interpreted as a command to cease a certain activity or as the initial character of a sequence that performs a special function. Cursor control sequences for many terminals and workstations use the escape character.
See also quote
A catchall directory, which usually contains miscellaneous
system data files (such as
termcap, the terminal capabilities
database).
A communications concept for local communication networks that interconnects different kinds of computers, information processing products, and office equipment. It is a 10-megabit-per-second baseband local area network (LAN) using carrier sense multiple access with collision detection (CSMA/CD). The network allows multiple stations to access the medium at will without prior coordination, and avoids contention by using carrier sense and deference, and detection and transmission.
An occurrence, or happening, that is significant to a transport user. Events are asynchronous, in that they do not happen as a result of an action taken by the user.
An executable image located in physical memory.
A mechanism by which transport providers notify transport users of the occurrence of significant events.
A data file created by a compiler that contains program information a computer can read, interpret, and execute. Also called an image or a binary file.
A line-oriented program for modifying the contents of text
files.
The
ex
editor is an extended version of the
ed
editor.
Data that is considered urgent. The semantics of this data are defined by the transport provider.
1. A representation of a value; for example, variables and constants appearing alone or in combination with operators.
2. In programming languages, a language construct for computing a value from one or more operands, such as literals, identifiers, array references, and function calls.
3. A configuration of signs.
A character other than a 7-bit ASCII character. An extended character can be a 1-byte code point with the eighth bit set (ordinal 128-255).
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
A technology that provides the means for moving data between computer devices at as much as three times the speed of SCSI (currently up to a billion bits per second, with even faster speeds expected). Fibre Channel, which works using optical fiber, coaxial cable, and twisted pair, is specified by a set of standards, specifically the Fibre Channel Physical and Signalling standard, ANSI X3.230-1994, which is also ISO 14165-1.
1. The basic unit of information in a record.
2.
In
awk,
one element of an input record.
See also record
One or more characters used to separate fields in a record.
A small unsigned integer that a UNIX system uses to identify a file. A file descriptor is created by a process through issuing an open system call for the file name. A file descriptor ceases to exist when it is no longer held by any process.
A sequence of characters written on a magnetic tape to signify the end of a data file.
See also EOF (end of file)
See globbing
An identifier that indicates a structure containing the file name.
The collection of files and file management structures on a physical or logical mass storage device.
1. A command that reads standard input data, modifies the data, and sends it to standard output.
2. A device or program that separates data, signals, or materials in accordance with specific criteria.
See option
A job that must be completed or interrupted before the shell will accept more commands; a job receiving input from a workstation or terminal.
See also background process
1. The command used to create and start a child process.
2.
The result of using
the
fork
command.
See also parent process
A Tru64 UNIX installation that creates new file systems
and loads a full copy of the operating system from the kit onto a system.
Any other version of the operating system, any layered products, and any patches
that previously existed on the system are overwritten.
A full installation
does not preserve system customizations (for example, user or data files)
because the root (/),
/usr, and
/var
file systems are re-created during the process.
See also update installation
An editor that displays an entire screen at a time. Also called a visual editor.
See also line editor
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
The sizes (in bytes) of cylinders, tracks, and sectors for a particular disk device.
See also disk label
See group ID (GID)
In programming languages, pertaining to information defined in one subdivision of a program and used in at least one other subdivision of the program; pertaining to information available to more than one program or subroutine.
In an editing environment, the process of having the system look through a document for specific characters, words, or groups of characters.
A UNIX term for the shell's process of wildcard file name expansion to develop a list of literal file names that the shell then passes to a command. The C shell permits the user to disable globbing by default; the Bourne, Korn, and POSIX shells require the user to quote or escape metacharacters in file names if globbing is not desired.
The command that invokes the
grep
program,
which is used to search specified files for lines containing characters that
match specified patterns, and then writes those matching lines to standard
output.
The name means Global Regular Expression Printer.
See also regular expression
1. A collection of users who can share access authorities for protected resources.
2. A list of names that are known together by a single name.
3. A set of related records that have the same value for a particular field in all records.
4. A series of records logically joined together.
See also login group
A unique number assigned to a group of related users. The group number can often be substituted in commands that take a group name as an argument.
See also user ID (UID), process ID (PID)
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
1.
A mechanism that allows
the
ln
command to assign more than one name to a file.
Both the new name and the file being linked must be in the same file system.
2.
The default result of
using the
ln
command.
See also symbolic link
An indexed database containing the contents of the
passwd
file.
The indexed database minimizes the search time needed
to retrieve information.
A method of transforming a search key into an address for the purpose of storing and retrieving items of data.
The hardware and microcode that provides the interface between system memory and a Small Computer System Interface (SCSI) bus.
See include file
A character in the ASCII character set that is not printable; for example, the DEL and ESC characters.
A file whose name begins with a period.
by default, the
ls
command omits such files from its listings.
In the C shell and the Korn shell, a command that displays the user's history list.
In the C shell and the Korn shell, a listing of the most recent commands entered by the user. Commands in the history list are available for recall, modification, and reexecution.
An environment variable containing the absolute pathname of the user's home directory.
See also $home, environment variable
A process variable containing the absolute pathname of the user's home directory.
See also $HOME, process variable
A directory that is owned by a specific user and from which that user's other directories descend in a hierarchy. Also known as a login directory.
See also working directory
1. The primary or controlling computer in a communications network.
2. A computer attached to a network.
The name given to a computer on the network.
The coding (markup) inserted in a file intended for display
on a World Wide Web browser that tells the browser how to display a Web page's
words.
The markup is done with
tags, which are command
words enclosed in angle brackets.
For example, the tag
<P>
creates a new paragraph; the tag
<TABLE>
begins the formatting
of a table.
Although the World Wide Web Consortium (W3C) promotes the standardization
of HTML, both Netscape and Microsoft browsers currently implement some features
differently and provide nonstandard extensions.
See also PDF file
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
I
A host-to-host protocol from the Internet Protocol suite that controls errors and the operations of the Internet Protocol (IP).
See also IP (Internet Protocol)
A C language precompiler directive specifying interpolation of a named file into the file being compiled. The interpolated file is a standard header file (indicated by placing its name in angle brackets) or any other file containing C language code (indicated by placing its name in double quotation marks). For example:
#include <header_file.h> #include "myfile.c"
The absolute pathname of header files
whose names are placed in angle brackets (<>) is
/usr/include/file.h.
See also include file
A text file that contains declarations used by a group of functions, programs, or users. Also known as a header file.
See also #include
The process of copying files that have been opened for reasons other than read-only access since the last backup was created and that meet the backup frequency criteria.
A source code error that causes the program to continually repeat the same set of instructions. For example, Instruction A sends the program execution to Instruction B, which in turn sends the program execution back to instruction A. Such a loop can only be interrupted by intervention from outside the program.
The command given by a UNIX system as the final step in the
boot procedure after the root file system is mounted.
The
init
program initializes the system by creating and controlling processes, which
are defined in the
inittab
file.
A process created by the system that performs system administration tasks, such as spawning login processes and handling the orderly shutdown from multiuser to single-user mode.
A feature of some shells that allows users to edit a current or previously entered command line.
The internal structure that describes the individual files in the operating system. There is one inode for each file. An inode contains the node, type, owner, and location of a file. A table of inodes is stored near the beginning of a file system.
A number specifying a particular inode file in the file system.
Data to be processed.
The specification of an input source other than standard input.
The part of a computer program that tells the computer what function to perform at that stage.
The capability of a computer program of making itself adaptable to the requirements of different native languages, local customs, and coded character sets, which means, essentially, that internationalized programs can run in any supported locale without having to be modified.
The term internationalization is often represented by the abbreviation I18N, with 18 representing the number of letters between the first and last letters of the word.
1. A collection of computing networks consisting of participants from major research institutions, universities, and government labs, including the National Science Foundation (NSF) and the NFSnet regional organizations. The Internet is not a commercial product, but rather a large project in support of research.
2. A collection of connected networks using the TCP/IP protocols.
A unique 32-bit number that identifies a host's connection to an internet network. An internet address consists of a network number and a host number.
The domain name system of the Internet, which consists of the following categories of hosts: COM, EDU, GOV, MIL, NET, ORG, and ARPA.
See also communication domain, domain name system, Internet
1. An event that causes a computer to digress from its normal processing stream in order to respond to the condition that triggered the digression. Upon completion of the digression, the normal processing stream is resumed at the point of interruption. Interrupts can be caused either by software instructions or by hardware events such as the completion of an I/O operation.
2. To trigger an interrupt.
Code in a program or operating system that performs actions in response to an interrupt.
The network layer protocol for the Internet protocol suite that provides the basis for the connectionless, best-effort packet delivery service. IP includes the Internet Control Message Protocol (ICMP) as an integral part. The Internet protocol suite is referred to as TCP/IP because IP is one of the two most fundamental protocols.
See IP router
A host that connects two or more internet networks. The IP router knows how to reach all the hosts on the networks to which it is attached. Also known as an IP gateway.
An international body composed of the national standards organizations of 89 countries. ISO issues standards on a vast number of goods and services, including networking software.
To perform the same function repeatedly on different data, often with the object of arriving at a result by successively closer approximation.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
A programming language developed by Sun Microsystems that is based on C++ but optimized for the distribution of program objects in a network such as the Internet. Java is somewhat simpler and easier to learn than C++ and has characteristics that give it other advantages over C++.
A Java applet is a small program, such as a window or a pull-down menu, written in Java.
An interpreted programming (script language) from Netscape. It is somewhat similar in capability to Microsoft's Visual Basic, Sun's Tcl, the UNIX-derived Perl, and IBM's REXX. In general, script languages are easier and faster to code in than the more structured and compiled languages such as C and C++. Script languages generally take longer to process than compiled languages, but are very useful for shorter programs.
1. A unit of work defined by a user to be done by a system. The term job sometimes refers to a representation of the job, such as a set of programs, files, and control statements to the operating system.
2. One or more related procedures or programs grouped into a procedure, identified by appropriate job control statements.
Facilities for monitoring and accessing background processes.
A number assigned to a job as it enters the system to distinguish the job from other jobs.
A list of the jobs that are waiting to be processed by the system.
The status of the work being done by a system.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
K
The command that invokes the
kdbx
program,
an interactive crash analysis and kernel debugging tool.
The
kdbx
program serves as a front end to the
dbx
debugger.
A program that lets programmers control the execution of a running kernel.
The integral part of the operating system that provides fundamental services to users and applications. Traditional kernels do the following:
Dispense such system resources as memory and execution time to tasks
Provide input and output services that allow tasks to access mass storage and other devices (and users and the computer to engage in a dialogue through a monitor and keyboard)
Manage communications to other computers residing on a network
Provide authentication services for users and tasks
Manage the organization and integrity of file system
The kernel has specialized knowledge of the hardware on which it runs.
See also shell, microkernel
1. A word that must be matched when retrieving information.
2. A reserved word whose presence is required in a file.
1. To stop the operation of a process. In most cases, a user can kill a foreground process by pressing Ctrl/c.
2. The Tru64 UNIX command that a user can issue to stop a background or suspended process. A superuser can use this command to stop any process on the system.
A command interpreter and interpreted programming language
developed by David Korn.
The Korn shell (ksh) is semantically
an extended version of the
Bourne shell, with constructs and commands to implement
enhanced features, including job control and command history recall.
The
POSIX
shell is a
superset of the Korn shell.
See also shell
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
See localization
See disk label
A device communications system that operates over a limited physical distance, offering high-speed communications channels optimized for connecting information-processing equipment.
An Internet standard directory service protocol that runs over TCP/IP. An LDAP server manages entries in a directory, and makes the information available to users and applications across the network; it can be used as a central repository of user information to identify and authenticate individuals. When used in this way, an LDAP server is similar to Network Information Services (NIS).
See also LAN (Local Area Network)
A protocol that supports communications between host computer systems and terminal servers with terminals, PCs, printers, modems, and other devices over local area networks (LANs).
See also LAN (Local Area Network)
An optional software product designed to be installed as an added feature of the Tru64 UNIX system.
The command that invokes the Lexical Analyzer Generator, a program for generating other programs that can organize input into units of meaning (symbols) called lexemes.
See also lexical analyzer, parser, yacc (Yet Another Compiler-Compiler)
A program or program fragment for analyzing input and assigning
elements of it to categories to assist in parsing the input.
The
lex
program assists in the creation of lexical analyzers.
See also parser
See lex
An interactive or noninteractive text editor that works on one line of text at a time.
See also full-screen editor
A directory entry referring to a file.
See also hard link, symbolic link
A single program that loads, relocates, and links compiled and assembled programs, routines, and subroutines to create an executable file. Also known as link loader and linker loader.
A program that checks C code for bugs, portability problems, and errors, such as mismatched argument types and uninitialized variables.
1. A value expression representing a constant.
2. A specific symbol that cannot be modified during the translation of a program.
A software environment that correctly handles the cultural conventions of a particular geographic area, such as China or France, and a language as it is used in that area. So by selecting a Chinese locale, for example, all commands, system messages, and keystrokes can be in Chinese characters and displayed in a way appropriate for Chinese.
See also internationalization
The computer system to which a user's terminal is directly connected.
The process of implementing local requirements within a computer system. Some of these requirements are addressed by locales. Each locale is a set of data that supports a particular combination of native language, cultural data, and codeset. The type of information a locale can contain and the interfaces that use a locale are subject to standardization.
The term "localization" is sometimes abbreviated as L10N, with 10 representing the number of letters between the first and last letters of the word.
See also internationalization
A file that indicates that operations on one or more other
files are restricted or prohibited.
The presence of the lock file can be used
as the indication, or the lock file can contain information describing the
nature of the restrictions.
For example, the Tru64 UNIX
setld
utility creates a lock file for each product kit subset that it installs.
If a given product includes subsets that require the presence of a previously
installed subset,
setld
places in the earlier subset's
lock file the names of the later subsets to prevent inadvertent deletion of
the earlier subset.
To begin using a computer system, usually by entering one's login name and a password to gain access to and communicate with the operating system as an authorized user.
See home directory
The primary classification that establishes the access permission for the files created by the user.
See also group
The name that identifies a user to a computer system and to other users of the system. When logging in to the system, the user enters this name and (usually) a password. Also known as user name.
The shell that a user uses by default upon logging in to the
system.
It is specified by the user's entry in the
passwd
file.
To stop using a computer system, usually by entering a command that tells the operating system that the user is ending the current session.
1. A sequence of instructions that is executed repeatedly until a specified condition is satisfied.
2. In the Tru64 UNIX virtual memory system, the page clusters in main memory that are repeatedly scanned for replacement.
See also infinite loop
The number assigned to a SCSI device to identify it to the SCSI driver.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
M
An instruction written as part of a source language, which when compiled into machine code will generate several machine code instructions.
See also instruction
A file that contains new and unread mail messages.
The mailbox
file is usually in the
/usr/spool/mail
directory.
A script that creates device special files for the devices
on a Tru64 UNIX system.
This script resides in the
/dev
directory.
A tool that builds programs and applications by testing to
see whether the source files that produce a given application are newer than
the target files produced from them.
If any source or intermediate file is
newer than its target,
make
performs the actions necessary
to rebuild the target file by following a set of rules.
The rules can be standard
(specified by default) or they can be explicit descriptions of the steps required.
The specification file used by the
make
tool.
The makefile specifies the names of target programs and describes rules
for their creation.
See also make
The command that displays reference pages on line; the name is a short form of manual.
See also apropos, reference page
See reference page
An environment variable whose value provides the default directory
search path used by the
See also search path
A process of reading a system's memory to proactively discover and handle memory errors.
A character that is interpreted by a computer system to mean something other than its obvious meaning. For example, the asterisk is often used to allow wildcard matching in file names.
A UFS file system that resides only in memory. No permanent data or file structures are written to disk. An MFS can improve read/write performance, but it is a volatile cache. The contents of an MFS are lost after a reboot, unmount operation, or power failure.
The Management Information Base defines a set of data elements that relate to network management. Many of these are standardized in the RFCs that are produced as a result of the Internet Engineering Task Force working group standardization effort of the Internet Society.
A type of kernel that delegates much of the work of memory management, task scheduling, and other services to nonkernel code. A microkernel provides only the basic primitives that control such operations on a specific processor architectures.
A term used to describe software that enables two other programs to work together. An example of middleware is the COM for Tru64 UNIX software.
A way of duplicating information on a disk to ensure that the information is still available in the event of a disk failure.
See also RAID (redundant array of independent disks), striping
The set of permissions for a file.
These permissions are often
expressed as three numbers, which represent an
octal
notation to set each bit in the permission code.
Users who are
given or denied permissions are
"owner,"
"group,"
and
"other"; the most common permissions given are read, write,
and execute.
The command used to change permissions is
chmod.
See OSF/Motif
A command used to make a file system available.
See also unmount
A directory file that is the name of a mounted file system.
A system with two or more processors sharing common physical memory.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
N
The service provided to client processes for identifying peer processes for communications purposes.
Software that is written in a language that compiles either to assembly language or directly to the computer's standard machine representation (object files). Native software is more efficient and runs much faster than translated or interpreted software; in addition, it can be tailored to make the most effective use of the machine's resources.
An interface that provides a mechanism to protect against certain kinds of network connectivity failures. NetRAIN integrates multiple network interfaces on the same local area network (LAN) segment into a single virtual interface called a NetRAIN set. One network interface in the set is always active while the others remain idle. If the active interface fails, one of the idle set members comes on line with the same IP address within an adjustable failover time period.
Two or more computing systems that are linked for the purpose of exchanging information and sharing resources.
A service that allows a system (the server) to make file systems available across a network for mounting on other systems (clients). When a client mounts an NFS file system, the client's users see the file system as if it were local to the client.
Refers to a file system that is mounted over a network via NFS rather than being physically connected (local) to the system on which it is mounted.
See also NFS (Network File System)
A distributed data lookup service for sharing information on a local area network (LAN). NIS allows you to coordinate the distribution of database information throughout your networked environment. NIS was formerly known as Yellow Pages.
See also NFS (Network File System)
One of the two supported architectures for multiprocessor systems, the other being symmetric multiprocessors (SMP). The NUMA architecture overcomes a drawback of traditional SMP systems that provide one interconnect, either a bus or a switch, that links all system resources. With NUMA, systems can be scaled to large numbers of CPUs without the system switch or bus becomming a performance bottleneck.
The command that calls the
nroff
program,
a member of the
roff
family of text formatters.
The
nroff
program produces ASCII output suitable for display or printing
on character-cell devices such as terminals and printers.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
A nonexecutable intermediate binary file created by a compiler. Object files are frequently used as libraries, to provide precompiled program elements for use in compiling a complete executable binary.
See also binary file, compiler
A number system that uses 8 as a base (radix). The octal system uses the digits 0 through 7, and each digit position represents a power of 8.
A system management process that is used to expand capacity, upgrade components, and replace failed components, while the operating system services and applications continue to run. This functionality (sometimes referred to as "hot-swap") provides the benefits of increased system uptime and availability during both scheduled and unscheduled maintenance.
A system that supports the International Organization for Standardization (ISO) Reference Model for Open System Interconnection (OSI).
In regular expressions, a character that is interpreted to
mean something other than its literal meaning.
For example, a pair of brackets
( [ ] ) form an operator that enables
a single-character match on any one of the characters enclosed by the brackets.
The process of selecting the specific method by which a program is to perform a given task such that the most effective use is made of time, I/O, or other resources.
1.
An argument that controls
how the shell executes a command.
Options are usually preceded by a hyphen
and appear with the command name on a command line; for example,
ls -a.
An option is often referred to as a flag or a switch.
2. An indicator or parameter that shows the setting of a switch.
3. A character that signals the occurrence of some condition, such as the end of a word.
4. An internal indicator that describes a condition to the CPU.
A consortium of software vendors formed for the purpose of developing and marketing widely compatible UNIX systems based on a common set of features.
A graphical user interface developed and licensed by the Open Group (originally by the Open Software Foundation). OSF/Motif is based on the X Window System. Also called Motif.
A set of international standards developed by the International Organization for Standardization. The goal of the OSI is that different vendors' computer systems can interconnect.
Usually, the user who creates a file. The owner has the right to change the list of users or groups who are permitted access to the file and the ways in which those users or groups may access the file. Ownership of a file can be reassigned by the system manager or superuser.
|
Click letter for quick access: [Special Characters] A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
P
For the Tru64 UNIX operating system loader, a collection of object entities that share a common name space. Symbol names are unique within a package. Symbols from different packages may bear identical symbol names, because they are distinguished by their package names.
A fixed-size unit of physical memory.
A set of subroutines that are specific to a particular Alpha operating system implementation. These subroutines provide operating-system primitives for context-switching interrupts, exceptions, and memory management.
The directory in which another directory resides. The directory that is contained in the parent is called a subdirectory.
A process that has created other processes, called its children. In the Tru64 UNIX system, every command that is not a shell built-in command creates a child process.
See also fork
A program or program fragment for interpreting input and determining
how to act upon it.
The
yacc
program assists in the creation
of parsers.
See also lexical analyzer
The sequence in which a program interprets information that is input to it. For example, a program using left-to-right parsing order interprets input reading "create a number; write the number" so that the number created by the first step is written. A program with right-to-left parsing order interprets the same input to mean that the program is to write a number that it created in some previous step and then to create a new number.
A physical portion of a disk.
Disks are divided into partitions
that are then assigned to hold various file systems.
For example, the root
file system is usually on the first partition, named
a.
The
/usr
file system is on a different partition, often
the
g
partition.
The use of partitions provides flexibility
and control of disk usage, but it is restricted in that it denies unlimited
use of all the available space on a given disk for a given file.
See also disk label, geometry
In an XTI transport connection, the transport user that did not initiate the connection.
See also client process, active user, XTI (X/Open Transport Interface)
1. The command by which users change their login password.
2.
The UNIX file in which
user passwords and associated information are stored; the file's pathname
is
/etc/passwd.
A file or a collection of files that contain fixes to problems. A patch may correct one or more problems. A collection of patches for a software product is sometimes referred to as a patch kit.
See also dupatch
An environment variable containing the user's search path
for commands.
Directory names in the
$PATH
variable are
separated with colons.
See also $path
A process variable containing the user's search path for commands.
Directory names in the
$path
variable are separated with
spaces.
See also $PATH
An ordered list of the directories in which the shell searches for the executable files named by commands that are not entered with a pathname and are not shell built-in commands.
The name of a file, concatenated onto a list of the directories
through which access to that file is achieved; hence, the complete name of
the file.
Absolute pathnames begin at the root directory and are written with
an initial slash (for example,
/usr/users/rolf/myfile.txt).
Relative pathnames begin at the user's working directory and are written without
the initial slash (for example,
rolf/myfile.txt).
The process of comparing input information (usually text) against a specified set of symbols (usually regular expressions) to find correspondences.
See also regular expression
A versatile scripting language that is often used to develop CGI (common gateway interface) programs for the World Wide Web, such as the forms you would use to order merchandise. Perl is similar in syntax to the C language and includes a number of popular UNIX facilities such as sed and awk. Perl is an interpreted language that can be compiled just before execution into either C code or cross-platform byte code. When compiled, a Perl program executes almost as fast as a fully precompiled C language program.
See also script
See permissions
See permissions
The constraints a user places on a file to control what other users or groups may read, write, or execute the file. There are three sets of permissions: those applied to the user, those applied to the user's group, and those applied to everyone else, called