glossary(9)glossary(9)NAMEglossary - description of common HP-UX terms
DESCRIPTION
HP-UX and other UNIX-like systems use a specialized vocabulary in which
certain words and terms have very specific meanings. This glossary is
intended as an aid in promoting exactness in use of these specialized
terms whose meanings sometimes differ from those that might be encoun‐
tered in other environments. References to other HP-UX documentation
are included as appropriate.
Entities in italics with a following parenthesized roman number (some‐
times with a capital letter), such as sh(1), wait(2), or fopen(3S)
refer to entries in the other sections of this manual. Items in refer
to other entries in this glossary. Items in (bold face in the online
manpages) are literals, such as file names and environment variables.
Any italicized manual names refer to separate manuals that are either
included with your system or available separately.
The definitions specifically reflect the HP-UX operating system,
although some terms and definitions are also derived from those in the
emerging IEEE POSIX standards and the Differences in wording exist to
more specifically reflect the characteristics of the HP-UX system.
GLOSSARY ENTRIES
. (dot)
A special file name that refers to the It can be used alone or at the
beginning of a directory path name. See also The also functions as a
special command in the POSIX, Bourne, and Korn shells, and has special
meaning in text editors and formatters, in parsing regular expressions
and in designating file names.
.. (dot-dot)
A special file name that refers to the If it begins a refers to the
parent of the current directory. If it occurs in a path name, refers
to the parent directory of the directory preceding in the path name
string. As a special case, refers to the current directory in any
directory that has no parent (most often, the See also
.o (dot-oh)
The suffix customarily given to a relocatable object file. The term is
sometimes used to refer to a relocatable object file. The format of
such files is sometimes called See a.out(4).
a.out
The name customarily given to an executable object code file on HP-UX.
The format is machine-dependent, and is described in a.out(4) for each
implementation. Object code that is not yet linked has the same for‐
mat, but is referred to as a (file. is also the default output file
name used by the linker, ld(1).
absolute path name
A path name beginning with a slash It indicates that the file's loca‐
tion is given relative to the and that the search begins there.
access
The process of obtaining data from or placing data in storage, or the
right to use system resources. Accessibility is governed by three
process characteristics: the effective user ID, the effective group ID,
and the group access list. The access(2) system call determines acces‐
sibility of a file according to the bit pattern contained in its amode
parameter, which is constructed to read, write, execute or check the
existence of a file. The access(2) system call uses the instead of the
and the instead of the
access groups
The group access list is a set of used in determining resource accessi‐
bility. Access checks are performed as described below in
access mode
An access mode is a form of access permitted to a file. Each implemen‐
tation provides separate read, write, and execute/search access modes.
address
A number used in information storage or retrieval to specify and iden‐
tify memory location. An is used to mark, direct, indicate destina‐
tion, instruct or otherwise communicate with computer elements.
In mail, is a data structure whose format can be recognized by all ele‐
ments involved in transmitting information. On a local system, this
might be as simple as the user's name, while in a networked system,
specifies the location of the resource to the network software.
In a text editor (such as or an locates the line in a file on which a
given instruction is intended.
For the specifies at what assembly-language instruction to execute a
given command.
In disk utilities such as might refer to a raw or the number, or other
file attribute.
In the context of peripheral devices, refers to a set of values that
specify the location of an I/O device to the computer. The exact
details of the formation of an address differ between systems.
address space
The range of memory locations to which a process can refer.
affiliation
See
agile addressing
An addressing scheme where an address or path to a logical unit that is
independent of the physical path. See intro(7) for more information.
appropriate privileges
Each implementation provides a means of associating privileges with a
process for function calls and function call options requiring special
privileges. In the HP-UX system, refers either to superuser status or
to a privilege associated with privilege groups (see setprivgrp(1M)).
archive
A file comprised of the contents of other files, such as a group of
object files (that is, used by the linker, ld(1)). An archive file is
created and maintained by ar(1) or similar programs, such as tar(1) or
cpio(1). An is often called a
ASCII
An acronym for American Standard Code for Information Interchange.
ASCII is the traditional System V coded character set and defines 128
characters, including both control characters and graphic characters,
each of which is represented by 7-bit binary values ranging from 0
through 127 decimal.
background process group
Any process group that is a member of a session which has established a
connection with a controlling terminal that is not in the foreground
process group.
backup
The process of making a copy of all or part of the file system in order
to preserve it, in case a system crash occurs (usually due to a power
failure, hardware error, etc.). This is a highly recommended practice.
block
(1) The fundamental unit of information HP-UX uses for access and
storage allocation on a mass storage medium. The size of a
block varies between implementations and between file systems.
In order to present a more uniform interface to the user, most
system calls and utilities use to mean 512 bytes, independent of
the actual block size of the medium. This is the meaning of
unless otherwise specified in the manual entry.
(2) On media such as 9-track tape that write variable length strings
of data, the size of those strings. is often used to distin‐
guish from a block contains several records, whereas the number
of records denotes the blocking factor.
block special file
A special file associated with a mass storage device (such as a hard
disk or tape cartridge drive) that transfers data in multiple-byte
blocks, rather than by series of individual bytes (see can be mounted.
A provides access to the device where hardware characteristics of the
device are not visible.
boot, boot-up
The process of loading, initializing, and running an operating system.
boot area
A portion of a mass storage medium on which the volume header and a
"bootstrap" program used in booting the operating system reside. The
is reserved exclusively for use by HP-UX.
boot ROM
A program residing in ROM (Read-Only Memory) that executes each time
the computer is powered up and is designed to bring the computer to a
desired state by means of its own action. The first few instructions
of a bootstrap program are sufficient to bring the remainder of the
program into the computer from an input device and initiate functions
necessary for computation. The function of the boot ROM is to run
tests on the computer's hardware, find all devices accessible through
the computer, and then load either a specified operating system or the
first operating system found according to a specific search algorithm.
bus address
A number which makes up part of the address HP-UX uses to locate a par‐
ticular device. The is determined by a switch setting on a peripheral
device which allows the computer to distinguish between two devices
connected to the same interface. A is sometimes called a "device
address".
character
An element used for the organization, control, or representation of
text. Characters include and
character set
A set of characters used to communicate in a native or computer lan‐
guage.
character special file
A special file associated with I/O devices that transfer data byte-by-
byte. Other byte-mode I/O devices include printers, nine-track mag‐
netic tape drives, and disk drives when accessed in "raw" mode (see A
has no predefined structure.
child process
A new process created by a pre-existing process via the fork(2) system
call. The new process is thereafter known to the pre-existing process
as its The pre-existing process is the of the new process. See and
clock tick
A rate used within the system for scheduling and accounting. It con‐
sists of the number of intervals per second as defined by that is used
to express the value in type was previously known as the defined con‐
stant
coded character set
A set of unambiguous rules that establishes a character set and the
one-to-one relationship between each character of the set and its cor‐
responding bit representation. is a
collating element
The smallest entity used in collation to determine the logical ordering
of strings (that is, the To accommodate native languages, a collating
element consists of either a single character, or two or more charac‐
ters collating as a single entity. The current value of the environ‐
ment variable determines the current set of collating elements.
collation
The logical ordering of strings in a predefined sequence according to
rules established by precedence. These rules identify a collation
sequence among the collating elements and also govern the ordering of
strings consisting of multiple collating elements, to accommodate
native languages.
collation sequence
The ordering sequence applied to when they are sorted. To accommodate
native languages, can be thought of as the relative order of as set by
the current value of the environment variable. Characters can be omit‐
ted from the collation sequence, or two or more collating elements can
be given the same relative order (see string(3C)).
command
A directive to perform a particular task. HP-UX commands are executed
through a called a HP-UX supports several shells, including the POSIX
shell (sh-posix(1)), the C shell (csh(1)), and the Korn shell (ksh(1)).
See sh(1) for more information about supported shells. Most commands
are carried out by an executable file, called a which might take the
form of a stand-alone unit of executable object code (a program) or a
file containing a list of other programs to execute in a given order (a
shell script). Scripts can contain references to other scripts, as
well as to object-code programs. A typical consists of the utility
name followed by arguments that are passed to the utility. For exam‐
ple, in the command, is the utility name and is an argument passed to
the utility.
command interpreter
A program which reads lines of text from standard input (typed at the
keyboard or read from a file), and interprets them as requests to exe‐
cute other programs. A command interpreter for HP-UX is called a See
sh(1) and related manual entries.
Command Set 1980
See
composite graphic symbol
A graphic symbol consisting of a combination of two or more other
graphic symbols in a single character position, such as a diacritical
mark and a basic letter.
control character
A character other than a graphic character that affects the recording,
processing, transmission, or interpretation of text. In the character
set, are those in the range 0 through 31, and 127. Control characters
can be generated by holding down the control key (which may be labeled
CTRL, CONTROL, or CNTL depending on your terminal), and pressing a
character key (as you would use SHIFT). These two-key sequences are
often written as, for example, or where stands for the control key.
controlling process
The session leader that establishes the connection to the Should the
terminal subsequently cease to be a controlling terminal for this ses‐
sion, the session leader ceases to be the controlling process.
controlling terminal
A terminal that is associated with a session. Each session can have at
most one controlling terminal associated with it and a controlling ter‐
minal is associated with exactly one session. Certain input sequences
from the controlling terminal cause signals to be sent to all processes
in the foreground process group associated with the controlling termi‐
nal.
Coordinated Universal Time (UTC)
See
CS/80, CS-80
A family of mass storage devices that communicate with the controlling
computer by means of a series of commands and data transfer protocol
referred to as the (Command Set 1980) command set. This command set
was implemented in order to provide better forward/backward compatibil‐
ity between models and generations of mass storage devices as techno‐
logical advances develop. Some mass storage devices support only a
subset of the full command set, and are usually referred to as (Subset
1980) devices.
crash
The unexpected shutdown of a program or system. If the operating sys‐
tem crashes, this is a "system crash", and requires the system to be
rebooted.
current directory
See
current working directory
See
daemon
A process which runs in the background, and which is usually immune to
termination instructions from a terminal. Its purpose is to perform
various scheduling, clean-up, and maintenance jobs. lpsched(1M) is an
example of a It exists to perform these functions for line printer jobs
queued by lp(1). An example of a permanent (that is, one that should
never die) is cron(1M).
data encryption
A method for encoding information in order to protect sensitive or pro‐
prietary data. For example, HP-UX automatically encrypts all users'
passwords. The encryption method used by HP-UX converts ASCII text
into a base-64 representation using the alphabet See passwd(4) for the
numerical equivalents associated with this alphabet.
default search path
The sequence of directory prefixes that sh(1), time(1), and other HP-UX
commands apply in searching for a file known by an relative path name
(that is, a path name not beginning with a It is defined by the envi‐
ronment variable (see environ(5)). login(1) sets equal to which means
that your working directory is the first directory searched, followed
by The search path can be redefined by modifying the value of This is
usually done in and/or in the file found in the home directory.
defunct process
See
delta
A term used in the (SCCS) to describe a unit of one or more textual
changes to an Each time an SCCS file is edited, changes made to the
file are stored separately as a The get(1) command is then used to
specify which deltas are to be applied to or excluded from the SCCS
file, thus yielding a particular version of the file. Contrast this
with the or editor, which incorporates changes into the file immedi‐
ately, eliminating any possibility of obtaining a previous version of
that file. A similar capability is provided by RCS files (see rcsin‐
tro(5)).
demon
Improper spelling of the UNIX word
device
A computer peripheral or an object that appears to an application as
such.
device address
See
device file
See
directory
A file that provides the mapping between the names of files and their
contents, and is manipulated by the operating system alone. For every
file name contained in a directory, that directory contains a pointer
to the file's The pointer is called a A file can have several links
appearing anywhere on the same file system. Each user is free to cre‐
ate as many directories as needed (using mkdir(1)), provided that the
of the new directory gives the permission to do so. Once a directory
has been created, it is ready to contain ordinary files and other
directories. An HP-UX directory is named and behaves exactly like an
ordinary file, with one exception: no user (including the superuser) is
allowed to write data on the directory itself; this privilege is
reserved for the HP-UX operating system.
By convention, a directory contains at least two links, and referred to
as and respectively. refers to the directory itself and refers to its
A directory containing only and is considered empty.
dot
See (
dot-dot
See (
dot-oh
See (
dot-oh file
See (
dot-oh format
See (
downshifting
The conversion of an uppercase character to its lowercase representa‐
tion.
dynamic loader
A routine invoked at process startup time that loads shared libraries
into a process's address space. The dynamic loader also resolves sym‐
bolic references between a program and the shared libraries, and ini‐
tializes the shared libraries' linkage tables. See dld.sl(5) (PA-RISC
systems) or dld.so(5) for details.
effective group ID
Every process has an that is used to determine A process's is deter‐
mined by the file (command) that process is executing. If that file's
set-group-ID bit is set (located in the mode of the file, see the
process's is set equal to the file's group ID. This makes the process
appear to belong to the file's group, perhaps enabling the process to
access files that must be accessed in order for the program to execute
successfully. If the file's set-group-ID bit is not set, the process's
is inherited from the process's parent. The setting of the process's
lasts only as long as the program is being executed, after which the
process's effective group ID is set equal to its real group ID. See
and
effective user ID
A process has an that is used to determine (and other permissions with
respect to system calls, if the effective user ID is 0, which means
superuser). A process's effective user ID is determined by the file
(command) that process is executing. If that file's set-user-ID bit is
set (located in the mode of the file, see the process's effective user
ID is set equal to the file's user ID. This makes the process appear
to be the file's owner, enabling the process to access files which must
be accessed in order for the program to execute successfully. (Many
HP-UX commands which are owned by such as and have their set-user-ID
bit set so other users can execute these commands.) If the file's set-
user-ID bit is not set, the process's effective user ID is inherited
from that process's parent. See and
end-of-file (EOF)
(1) The data returned when attempting to read past the logical end
of a file via stdio(3S) routines. In this case, end-of-file is
not properly a character.
(2) The ASCII character
(3) A character defined by stty(1) or ioctl(2) (see termio(7)) to
act as end-of-file on your terminal. Usually this is
(4) The return value from read(2) that indicates end of data.
environment
The set of defined shell variables (such as and others) that define the
conditions under which user commands run. These conditions can include
user terminal characteristics, home directory, and default search path.
Each shell variable setting in the current process is passed on to all
that are created, provided that each shell variable setting has been
exported via the command (see sh(1)). Unexported shell variable set‐
tings are meaningful only to the current process, and any child pro‐
cesses created get the default settings of certain shell variables by
executing or
EOF
See
Epoch
The time period beginning at 0 hours, 0 minutes, 0 seconds, () on Janu‐
ary 1, 1970. Increments quantify the amount of time elapsed from the
Epoch to the referenced time.
Leap seconds, which occur at irregular intervals, are not reflected in
the count of seconds between the Epoch and the referenced time. (Four‐
teen leap seconds occurred in the years 1970 through 1988.)
FIFO special file
A type of Data written to a is read on a first-in-first-out basis.
Other characteristics are described in open(2), read(2), write(2) and
lseek(2).
file
A stream of bytes that can be written to and/or read from. A has cer‐
tain attributes, including permissions and type. File types include
network special file, and Every file must have a that enables the user
(and many of the HP-UX commands) to refer to the contents of the file.
The system imposes no particular structure on the contents of a file,
although some programs do. Files can be accessed serially or randomly
(indexed by byte offset). The interpretation of file contents and
structure is up to the programs that access the file.
file access mode
A characteristic of an that determines whether the described file is
open for reading, writing, or both. (See open(2).)
file access permissions
Every file in the has a set of access permissions. These permissions
are used in determining whether a process can perform a requested oper‐
ation on the file (such as opening a file for writing). Access permis‐
sions are established when a file is created via the open(2) or
creat(2) system calls, and can be changed subsequently through the
chmod(2) call. These permissions are read by stat(2) or fstat(2).
File access controls whether a file can be read, written, or executed.
Directory files use the execute permission to control whether or not
the directory can be searched.
are interpreted by the system as they apply to three different classes
of users: the of the file, the users in the file's and anyone else
("other"). Every file has an independent set of access permissions for
each of these classes. When an access check is made, the system
decides if permission should be granted by checking the access informa‐
tion applicable to the caller.
Read, write, and execute/search permissions on a file are granted to a
process if any of the following conditions are met:
· The process's is superuser.
· The process's matches the user ID of the owner of the file and the
appropriate access bit of the portion (0700) of the file mode is
set.
· The process's does not match the user ID of the owner of the file,
and either the process's matches the group ID of the file, or the
group ID of the file is in the process's group access list, and
the appropriate access bit of the portion (070) of the file mode
is set.
· The process's does not match the user ID of the owner of the file,
and the process's does not match the group ID of the file, and the
group ID of the file is not in the process's group access list,
and the appropriate access bit of the "other" portion (07) of the
file mode is set.
Otherwise, the corresponding permissions are denied.
file descriptor
A small unique, per-process, nonnegative integer identifier that is
used to refer to a file opened for reading and/or writing. Each refers
to exactly one
A is obtained through system calls such as creat(2), fcntl(2), open(2),
pipe(2), or dup(2). The is used as an argument by calls such as
read(2), write(2), ioctl(2), and close(2).
The value of a has a range from 0 to one less than the system-defined
maximum. The system-defined maximum is the value in
file group class
A process is in the of a file if the process is not the and if the or
one of the of the process matches the group ID associated with the
file.
file hierarchy
The collection of one or more available on a system. All in these are
organized in a single hierarchical structure in which all of the non‐
terminal nodes are Because multiple can refer to the same the directory
is properly described as a directed graph.
file name
A string of up to 14 bytes (or 255 bytes on file systems that support
long file names) used to refer to an ordinary file, special file, or
directory. The byte values NUL (null) and slash cannot be used as
characters in a file name. Note that it is generally unwise to use or
as part of file names because the shell attaches special meaning to
these characters (see sh(1), csh(1), or ksh(1)). Avoid beginning a
file name with or because to some programs, these characters signify
that a command argument follows. A file name is sometimes called a
path name component. Although permitted, it is inadvisable to use
characters that do not have a printable graphic on the hardware you
commonly use, or that are likely to confuse your terminal.
file name portability
File names should be constructed from the because the use of other
characters can be confusing or ambiguous in certain contexts.
file offset
The file offset specifies the position in the file where the next I/O
operation begins. Each associated with either a regular file or spe‐
cial file has a There is no file offset specified for a or
file other class
A process is in the if the process is not in the or
file owner class
A process is in the if the of the process matches the user ID of the
file.
file permission bits
See
file pointer
A data element obtained through any of the fopen(3S) standard I/O
library routines that "points to" (refers to) a file opened for reading
and/or writing, and which keeps track of where the next I/O operation
will take place in the file (in the form of a byte offset relative to
the beginning of the file). After obtaining the file pointer, it must
thereafter be used to refer to the open file when using any of the
standard I/O library routines. (See stdio(3S) for a list of these rou‐
tines.)
file serial number
A file-system-unique identifier for a given file, also known as the
file's Each identifies exactly one are not necessarily unique across in
the
file status flags
Part of an These flags can be used to modify the behavior of system
calls that access the file described by the
file system
A collection of and supporting data structures residing on a mass stor‐
age volume. A file system provides a name space for referring to those
files. Refer to the System Administrator manuals supplied with your
system for details concerning file system implementation and mainte‐
nance.
file times update
Each file has three associated time values that are updated when file
data is accessed or modified, or when the file status is changed.
These values are returned in the file characteristics structure, as
described in For each function in HP-UX that reads or writes file data
or changes the file status, the appropriate time-related files are
noted as "marked-for-update". When an update point occurs, any marked
fields are set to the current time and the update marks are cleared.
One such update point occurs when the file is no longer open for any
process. Updates are not performed for files on
filter
A command that reads data from the standard input, performs a transfor‐
mation on the data, and writes it to the standard output.
foreground process group
Each session that has established a connection with a controlling ter‐
minal has exactly one process group of the session as a foreground
process group of that controlling terminal. The foreground process
group has certain privileges when accessing its controlling terminal
that are denied to background process groups. See read(2) and
write(2).
foreground process group ID
The process group ID of the foreground process group.
fork
An HP-UX system call (see fork(2)), which, when invoked by an existing
process, causes a new process to be created. The new process is called
the the existing process is called the The child process is created by
making an exact copy of the parent process. The parent and child pro‐
cesses are able to identify themselves by the value returned by their
corresponding call (see fork(2) for details).
graphic character
A character other than a control character that has a visual represen‐
tation when hand-written, printed, or displayed.
group
See
group ID
Associates zero or more users who must all be permitted to access the
same set of files. The members of a group are defined in the files and
(if it exists) via a numerical group ID that must be between zero and
inclusive. Users with identical group IDs are members of the same
group. An ASCII group name is associated with each group ID in the
file A group ID is also associated with every file in the and the mode
of each file contains a set of permission bits that apply only to this
group. Thus, if you belong to a group that is associated with a file,
and if the appropriate permissions are granted to your group in the
file's mode, you can access the file. When the identity of a group is
associated with a process, a group ID value is referred to as a an a or
a See also and
group access list
A set of used in determining resource accessibility. Access checks are
performed as described in
hardware path
A numeric string associated to a system component (bus, card, attached
I/O device, and so on) and providing information related to the compo‐
nent location.
hierarchical directory
A directory (or file system) structure in which each directory can con‐
tain other directories as well as files.
home directory
The directory name given by the value of the environment variable When
you first log in, login(1) automatically sets to your You can change
its value at any time. This is usually done in the file contained in
your Setting does not affect your it simply gives you a convenient way
of referring to what is probably your most commonly used directory.
host name
A string of bytes that uniquely identifies the system in the network.
The host name for your system can be viewed and/or set with the host‐
name(1) command. More information can be found in the hostname(5) man‐
page. See also
image
The current state of your computer (or your portion of the computer, on
a multiuser system) during the execution of a command. Often thought
of as a "snapshot" of the state of the machine at any particular moment
during execution.
init
A that performs initialization, is the ancestor of every other process
in the system, and is used to start processes. usually has a of See
init(1M).
interleave factor
A number that determines the order in which sectors on a mass storage
medium are accessed. It can be optimized to make data acquisition more
efficient.
inode
An is a structure that describes a file and is identified in the system
by a Every file or directory has associated with it an Permissions that
specify who can access the file and how are kept in a 9-bit field that
is part of the The also contains the file size, the user and group ID
of the file, the number of links, and pointers to the disk blocks where
the file's contents can be found. Each connection between an and its
entry in one or more directories is called a
inode number
See
Internal Terminal Emulator (ITE)
The "device driver" code contained in the HP-UX kernel that is associ‐
ated with the computer's built-in keyboard and display or with a par‐
ticular keyboard and display connected to the computer, depending on
the Series and Model of system processor. See and the System Adminis‐
trator manuals supplied with your system for details.
internationalization
The concept of providing software with the ability to support the and
of the user.
interrupt signal
The signal sent by (see signal(2)). This signal generally terminates
whatever program you are running. The key which sends this signal can
be redefined with ioctl(2) or stty(1) (see termio(7)). It is often the
ASCII DEL (rubout) character (the DEL key) or the BREAK key. is often
used instead.
intrinsic
See
I/O redirection
A mechanism provided by the HP-UX shell for changing the source of data
for standard input and/or the destination of data for standard output
and standard error. See sh(1).
ITE
See
job control
Job control allows users to selectively stop (suspend) execution of
processes and continue (resume) their execution at a later time.
The user employs this facility via the interactive interface jointly
supplied by the system terminal driver and certain shells (see sh(1)).
The terminal driver recognizes a user-defined "suspend character",
which causes the current foreground process group to stop and the
user's job control shell to resume. The job control shell provides
commands that continue stopped process groups in either the foreground
or background. The terminal driver also stops a background process
group when any member of the background process group attempts to read
from or write to the user's terminal. This allows the user to finish
or suspend the without interruption and continue the stopped at a more
convenient time.
See stty(1), sh(1), and related shell entries for usage and installa‐
tion details, and the shell entries plus signal(2) and termio(7) for
implementation details.
kernel
The HP-UX operating system. The kernel is the executable code respon‐
sible for managing the computer's resources, such as allocating memory,
creating processes, and scheduling programs for execution. The kernel
resides in RAM (random access memory) whenever HP-UX is running.
LANG
An environment variable used to inform a computer process of the user's
requirements for and
legacy device special file
A special file associated with an I/O device (tape, disk, and so on),
locked to a particular physical containing hardware path information
such as SCSI bus, target, and LUN in the device file name and minor
number. See intro(7) for more information.
legacy hardware path
A hardware path following the legacy format conventions, that is, a
series of bus-nexus addresses separated by (slash) characters, leading
to a host bus adapter (HBA). Beneath the HBA, additional address ele‐
ments are separated by (period) characters. All elements are repre‐
sented in decimal. See intro(7) for more information.
library
A file containing a set of subroutines and variables that can be
accessed by user programs. Libraries can be either archives or shared
libraries. For example, and are libraries containings all functions of
Section 2 and all functions of Section 3 that are marked (3C) and (3S)
in the Similarly, and are libraries containing all functions in Section
3 that are marked (3M) in the See intro(2) and intro(3C).
LIF
See
line
A sequence of text characters consisting of zero or more nonnewline
characters plus a terminating newline character.
link
is a synonym for It is an object that associates a file name with any
type of file. The information constituting a includes the name of the
file and where the contents of that file can be found on a mass storage
medium. One physical file can have several links to it. Several
directory entries can associate names with a given file. If the links
appear in different directories, the file may or may not have the same
name in each. However, if the links appear in one directory, each link
must have a unique name in that directory. Multiple links to directo‐
ries are not allowed (except as created by a user with appropriate
privileges). See ln(1), link(2), unlink(2), and
Also, to prepare a program for execution; see
link count
The number of directory entries that refer to a particular file.
linker
A program that combines one or more object programs into one program,
searches libraries to resolve user program references, and builds an
executable file in format. This executable file is ready to be exe‐
cuted through the program loader, exec(2). The linker is invoked with
the ld(1) command. The linker is often called a
local customs
The conventions of a geographical area or territory for such things as
date, time and currency formats.
localization
The process of adapting existing software to meet the local language,
customs, and character set requirements of a particular geographical
area.
Logical Interchange Format (LIF)
A standard format for mass storage implemented on many Hewlett-Packard
computers to aid in media transportability. See lif(4) for more
detail.
login
The process of gaining access to HP-UX. This consists of successful
execution of the login sequence defined by login(1), which varies
depending on the system configuration. It requests a name and possibly
one or more passwords.
login directory
The directory in which you are placed immediately after you log in.
This directory is defined for each user in the file The shell variable
is set automatically to your by login(1) immediately after you log in.
See
LUN
LUN refers to an end device, such as a disk or tape or a piece of logi‐
cal storage in a disk array (mass storage term). Also known as a Logi‐
cal Unit (LU).
LUN hardware path
A virtualized path that can represent multiple paths to a single mass
storage device. It starts with a virtual bus-nexus (known as the with
an address of 64000. Addressing beneath that virtual root node con‐
sists of a virtual bus address and a virtual LUN identifier, delimited
by (slash) characters. See intro(7) for more information.
lunpath hardware path
A hardware path to a LUN. It is composed of a series of bus-nexus
addresses separated by (slash) characters, leading to a host bus
adopter (HBA). Beneath the HBA, additional address elements are repre‐
sented in hexadecimal. The first elements represent a transport-depen‐
dent target address. The final element is a LUN address, which is the
64-bit representation of the LUN identifier reported by the target.
See intro(7) for more information.
magic number
The first word of an format or archive file. This word contains the
system ID, which states what machine (hardware) the file will run on,
and the file type (executable, sharable executable, archive, etc.).
major number
A number used exclusively to create special files that enable I/O to or
from specific devices. This number indicates which device driver to
use for the device. Refer to mknod(2) and the System Administrator
manual supplied with your system for details.
message catalog
Program strings, such as program messages and prompts, are stored in a
corresponding to a particular geographical area. Retrieval of a string
from a is based on the value of the user's environment variable (see
message queue identifier (msqid)
A unique positive integer created by a msgget(2) system call. Each has
a message queue and a data structure associated with it. The data
structure is referred to as and contains the following members:
Message queue identifiers can be created using ftok(3C).
is a structure that specifies the message operation permission (see
below). This structure includes the following members:
is the number of messages currently on the queue. is the maximum num‐
ber of bytes allowed on the queue. is the process id of the last
process that performed a operation. is the process id of the last
process that performed a operation. is the time of the last operation,
is the time of the last operation, and is the time of the last
msgctl(2) operation that changed a member of the above structure.
message operation permissions
In the msgop(2) and msgctl(2) system call descriptions, the permission
required for an operation is indicated for each operation. Whether a
particular process has these permissions for an object is determined by
the object's permission mode bits as follows:
Read by user
Write by user
Read, Write by group
Read, Write by others
Read and Write permissions on a are granted to a process if one or more
of the following are true:
· The process's effective user ID is superuser.
· The process's effective user ID matches in the data structure
associated with and the appropriate bit of the "user" portion
(0600) of is set.
· The process's effective user ID does not match and either the
process's effective group ID matches or one of is in the process's
group access list and the appropriate bit of the "group" portion
(00060) of is set.
· The process's effective user ID does not match and the process's
effective group ID does not match and neither of is in the
process's group access list and the appropriate bit of the "other"
portion (06) of is set.
Otherwise, the corresponding permissions are denied.
metacharacter
A character that has special meaning to the HP-UX shell, as well as to
commands such as and (see ed(1), find(1), and grep(1)). The set of
metacharacters includes: , and Refer to sh(1) and the related shell
manual entries for the meaning associated with each. See also
minor number
A number that is an attribute of special files, specified during their
creation and used whenever they are accessed, to enable I/O to or from
specific devices. This number is passed to the device driver and is
used to select which device in a family of devices is to be used, and
possibly some operational modes. The exact format and meaning of the
depends both on the driver and on the addressing format (legacy or
agile) being used. In legacy format, the minor number encodes path
information, but in agile format, the minor number is opaque and based
on the WWID.
mode
A 16-bit word associated with every file in the file system, stored in
the The least-significant 12 bits of the determine the read, write, and
execute permissions for the file owner, file group, and all others, and
contain the set-user-ID, set-group-ID, and sticky bits. The least-sig‐
nificant 12 bits can be set by the chmod(1) command if you are the
file's owner or the superuser. These 12 bits are sometimes referred to
as The most-significant 4 bits specify the file type for the associated
file and are set as the result of open(2) or mknod(2) system calls.
mountable file system
A removable blocked file system contained on some mass storage medium
with its own root directory and an independent hierarchy of directories
and files. See and mount(1M).
msqid
See
Multiplexer (MUX)
Multiplexer (MUX) is a high-speed serial communication multiple port
product. It combines various signals for transmission over a single
channel and provides intelligent communication functions to off-load
CPU serial communication processing tasks.
multiuser state
The condition of the HP-UX operating system in which terminals (in
addition to the system console) allow communication between the system
and its users. By convention, multiuser run level is set at state 2,
which is usually defined to contain all the terminal processes and
needed in a multiuser environment. Run levels are table driven, and
are specified by init(1M), which sets the run level by looking at the
file Do not confuse the multiuser system with the multiuser state. A
multiuser system is a system which can have more than one user actively
communicating with the system when it is in the multiuser state. The
multiuser state removes the single-user restriction imposed by the sin‐
gle-user state (see inittab(4)).
native language
A computer user's spoken or written language, such as Chinese, Dutch,
English, French, German, Greek, Italian, Katakana, Korean, Spanish,
Swedish, Turkish, and so on.
Network File System (NFS)
The Network File System (NFS) allows a client node to perform transpar‐
ent file access over the network.
By using NFS, a client node operates on files residing on a variety of
servers and server architectures, and across a variety of operating
systems. File access calls on the client (such as read requests) are
converted to NFS protocol requests and sent to the server system over
the network. The server receives the request, performs the actual file
system operation, and sends a response back to the client.
NFS operates in a stateless manner using remote procedure calls (RPC)
built on top of an external data representation (XDR) protocol. The
RPC protocol enables version and authentication parameters to be
exchanged for security over the network.
A server grants access to a specific file system to clients by adding
an entry for that file system to the server's file.
Native Language Support (NLS)
A feature of HP-UX that provides the user with internationalized soft‐
ware and the application programmer with tools to develop this soft‐
ware.
newline character
The character with an ASCII value of 10 (line feed) used to separate
lines of characters. It is represented by in the C language and in
various utilities. The terminal driver normally interprets a carriage-
return/line-feed sequence sent by a terminal as a single newline char‐
acter (but see tty(7) for full details)
NLS
See
NLSPATH
An environment variable used to indicate the search path for message
catalogs (see
node name
A string of bytes which uniquely identifies the system in the local
network. Unlike the the node name cannot include domain names. It can
be viewed and/or set with the uname(1) command. The node and host
names are usually set to the same value as application programs some‐
times use the node and host names interchangeably.
nonspacing characters
Characters, such as a diacritical mark or accents, that are used in
combination with other characters to form composite graphic symbols
commonly found in non-English languages.
open file
A file that is currently associated with a file descriptor.
open file description
A record of how a process or a group of processes is accessing a file.
Each refers to exactly one but an can be referred to by more than one
file descriptor. The and are attributes of an
ordinary file
A type of HP-UX file containing ASCII text (for example, program
source), binary data (for example, executable code), etc. Ordinary
files can be created by the user through I/O redirection, editors, or
HP-UX commands.
orphan process
A that is left behind when a terminates for any reason. The process
(see init(1M)) inherits (that is, becomes the effective parent of) all
orphan processes.
orphaned process group
A process group in which the parent of every member is either itself a
member of the group or is not a member of the group's session.
owner
The owner of a file is usually the creator of that file. However, the
ownership of a file can be changed by the superuser or the current
owner with the chown(1) command or the chown(2) system call. The file
owner is able to do whatever he wants with his files, including remove
them, copy them, move them, change their contents, etc. The owner can
also change the files' modes.
parent directory
The directory one level above a directory in the All directories except
the have one (and only one) parent directory. The has no parent. See
also and
parent process
Whenever a new process is created by a currently-existing process (via
fork(2)), the currently existing process is said to be the parent
process of the newly created process. Every process has exactly one
parent process (except the process, see but each process can create
several new processes with the fork(2) system call. The parent process
ID of any process is the of its creator.
parent process ID
A new process is created by a currently active process. The of a
process is the process ID of its creator for the lifetime of the cre‐
ator. After the creator's lifetime has ended, the is the process ID of
password
A string of ASCII characters used to verify the identity of a user.
Passwords can be associated with users and groups. If a user has a
password, it is automatically encrypted and entered in the second field
of that user's line in the file. A user can create or change his or
her own password by using the passwd(1) command.
path name
A sequence of directory names separated by slashes, and ending with any
file name. All file names except the last in the sequence be directo‐
ries. If a path name begins with a it is an otherwise, it is a A path
name defines the path to be followed through the hierarchical file sys‐
tem in order to find a particular file.
More precisely, a path name is a null-terminated character string con‐
structed as follows:
where <file-name> is a string of one or more characters other than the
ASCII slash and null, and <dirname> is a string of one or more charac‐
ters (other than the ASCII slash and null) that names a directory.
File and directory names can consist of up to 14 characters on systems
supporting short file names and up to 255 characters on systems sup‐
porting long file names.
A by itself names the Two or more slashes in succession are treated as
a single slash.
Unless specifically stated otherwise, the null or zero-length path name
is treated as though it named a nonexistent file.
path name resolution
The process that resolves a path name to a particular file in a Multi‐
ple path names can resolve to the same file, depending on whether reso‐
lution is sought in absolute or relative terms (see below). Each file
name in the path name is located in the directory specified by its pre‐
decessor (for example, in the path name fragment file is located in
directory fails if this cannot be accomplished.
If the path name begins with a slash, the predecessor of the first file
name in the path name is understood to be the of the process, and the
path name is referred to as an If the path name does not begin with a
slash, the predecessor of the first file name of the path name is
understood to be the current working directory of the process, and the
path name is referred to as a A path name consisting of a single slash
resolves to the root directory of the process.
path prefix
A with an optional ending that refers to a
permission bits
The nine least-significant bits of a file's are referred to as file
These bits determine read, write, and execute permissions for the
file's the file's and all others. The bits are divided into three
parts: owner, group and other. Each part is used with the correspond‐
ing file class of processes. The bits are contained in the file mode,
as described in stat(5). The detailed usage of the file permission
bits in access decisions is described in
persistent device special file
A device file for mass storage devices, which is associated with a LUN
hardware path, and thus transparently supports and multipathing. In
other words, a persistent device special file is unchanged if the LUN
is moved from one host bus adapter (HBA) to another, moved from one
switch/hub port to another, presented via a different target port to
the host, or configured with multiple hardware paths. See intro(7) for
more information on device special files.
PIC
See
pipe
An interprocess I/O channel used to pass data between two processes.
It is commonly used by the to transfer data from the standard output of
one process to the standard input of another. On a command line, a
pipe is signaled by a vertical bar Output from the command to the left
of the vertical bar is channeled directly into the standard input of
the command on the right.
portable file name character set
The following set of graphical characters are portable across conform‐
ing implementations of IEEE Standard P1003.1:
The last three characters are the dot, underscore and hyphen charac‐
ters, respectively. The hyphen should not be used as the first charac‐
ter of a portable file name.
position-independent code (PIC)
Object code that can run unmodified at any virtual address. Position-
independent code can use PC-relative addressing modes and/or linkage
tables. It is most often used in shared libraries, in which case the
linkage tables are initialized by the dynamic loader. Position-inde‐
pendent code is generated when the or compiler option is specified.
privileged groups
A is a group that has had a (see getprivgrp(2)) operation performed on
it, giving it access to some system calls otherwise reserved for the
superuser. See
process
An invocation of a program, or the execution of an image (see Although
all commands and utilities are executed within processes, not all com‐
mands or utilities have a one-to-one correspondence with processes.
Some commands (such as execute within a process, but do not create any
new processes. Others (such as in the case of create multiple pro‐
cesses. Several processes can be running the same program, but each
can be different data and be in different stages of execution. A
process can also be thought of as an and single thread of control that
executes within that address space and its required system resources.
A is created by another process issuing the fork(2) function. The
process that issues fork(2) is known as the and the new process created
by the fork(2) as the
process 1
See
process group
Each process in the system is a member of a This grouping permits the
signaling of related processes. A newly created process joins the
process group of its creator.
process group ID
Each process group in the system is uniquely identified during its
lifetime by a a positive integer less than or equal to A cannot be
reused by the system until the process group lifetime ends.
process group leader
A is a process whose process ID is the same as its process group ID.
process group lifetime
A period of time that begins when a is created and ends when the last
remaining process in the group leaves the group, either due to process
termination or by calling the setsid(2) or setpgid(2) functions.
process ID
Each active process in the system is uniquely identified during its
lifetime by a positive integer less than or equal to called a A process
ID cannot be reused by the system until after the process lifetime
ends. In addition, if there exists a process group whose process group
ID is equal to that process ID, the process ID cannot be reused by the
system until the process group lifetime ends.
process lifetime
After a process is created with a fork(2) function, it is considered
active. Its thread of control and exist until it terminates. It then
enters an inactive state where certain resources may be returned to the
system, although some resources, such as the are still in use. When
another process executes a or function (see wait(2)) for an inactive
process, the remaining resources are returned to the system. The last
resource to be returned to the system is the process ID. At this time,
the lifetime of the process ends.
program
A sequence of instructions to the computer in the form of binary code
(resulting from the compilation and assembly of program source).
prompt
The characters displayed by the on the terminal indicating that the
system is ready for a command. The prompt is usually a dollar sign for
ordinary users in the C shell) and a pound sign for the superuser, but
you can redefine it to be any string by setting the appropriate shell
variable (see sh(1) and related entries). See also
quit signal
The signal (see signal(2). The quit signal is generated by typing the
character defined by the teletype handler as your quit signal. (See
stty(1), ioctl(2), and termio(7).) The default is the ASCII FS charac‐
ter (ASCII value 28) generated by typing This signal usually causes a
running program to terminate and generates a file containing the "core
image" of the terminated process. The core image is useful for debug‐
ging purposes. (Some systems do not support core images, and on those
systems no such file is generated.)
radix character
The character that separates the integer part of a number from the
fractional part. For example, in American usage, the is a decimal
point, while in Europe, a comma is used.
raw disk
The name given to a disk for which there exists a that allows direct
transmission between the disk and the user's read or write buffer. A
single read or write call results in exactly one I/O call.
read-only file system
A characteristic of a that prevents file system modifications.
real group ID
A positive integer which is assigned to every user on the system. The
association of a user and his or her is done in the file The modifier
"real" is used because a user can also have an The real group ID can
then be mapped to a group name in the file although it need not be.
Thus, every user is a member of some group (which can be nameless),
even if that group has only one member.
Every time a process creates a child process (via fork(2)), that
process has a real group ID equal to the parent process's real group
ID. This is useful for determining file access privileges within the
process.
real user ID
A positive integer which is assigned to every user on the system. A
real user ID is assigned to every valid name in the file The modifier
"real" is used because a user can also have an (see
Every time a process creates a child process (via fork(2)), that
process has a real user ID equal to the parent process's real user ID.
This is useful for determining file access privileges within the
process.
regular expression
A string of zero or more characters that selects text. All the charac‐
ters contained in the string might be literal, meaning that the regular
expression matches itself only; or one or more of the characters might
be a meaning that a single regular expression could match several lit‐
eral strings. Regular expressions are most often encountered in text
editors (such as ed(1), ex(1), or vi(1)), where searches are performed
for a specific piece of text, or in commands that were created to
search for a particular string in a file (most notably grep(1)). Regu‐
lar expressions are also encountered in the shell, especially when
referring to file names on command lines.
regular file
A type of that is a randomly accessible sequence of bytes, with no fur‐
ther structure imposed by the system. Its size can be extended. A
regular file is also called an
relative path name
A that does not begin with a It indicates that a file's location is
given relative to your current and that the search begins there
(instead of at the For example, searches for the directory in your cur‐
rent working directory; then is searched for the file
__restrict
A macro that is optionally applied to the function prototype when the
application developer directly or indirectly selects C99 conformance.
If the user chooses C99 conformance, the macro is changed to the key‐
word. Otherwise, the macro is expanded to an empty string.
root directory
(1) The highest level directory of the hierarchical file system,
from which all other files branch. In HP-UX, the character
refers to the The root directory is the only directory in the
file system that is its own
(2) Each process has associated with it a concept of a root direc‐
tory for the purpose of resolving path name searches for those
paths beginning with A process's root directory need not be the
root directory of the root file system, and can be changed by
the chroot(1M) command or chroot(2) system call. Such a direc‐
tory appears to the process involved to be its own parent direc‐
tory.
root volume
The mass storage volume which contains the boot area (which contains
the HP-UX kernel) and the of the HP-UX file system.
saved group ID
Every process has a saved group ID that retains the process's from the
last successful exec(2) or (see setresuid(2)), or from the last supe‐
ruser call to (see setuid(2)) or setresuid(2). permits a process to
set its effective group ID to this remembered value. Consequently, a
process that executes a program with the set-group-ID bit set and with
a group ID of 5 (for example) can set its effective group ID to 5 at
any time until the program terminates. See exec(2), setuid(2), and The
saved group ID is also known as the
saved process group ID
Every process has a saved process group ID that retains the process's
group ID from the last successful exec(2). See setpgrp(2), termio(7),
and
saved user ID
Every process has a that retains the process's from the last successful
exec(2) or setresuid(2), or from the last superuser call to setuid(2).
setuid(2) permits a process to set its effective user ID to this remem‐
bered value. Consequently, a process which executes a program with the
set-user-ID bit set and with an owner ID of 5 (for example) can set its
effective user ID to 5 at any time until the program terminates. See
exec(2), setuid(2), and The saved user ID is also known as the
saved set-group-ID
See
saved set-user-ID
See
SCCS
See
Source Code Control System (SCCS)
A set of HP-UX commands that enables you to store changes to an as sep‐
arate "units" (called These units, each of which contains one or more
textual changes to the file, can then be applied to or excluded from
the SCCS file to obtain different versions of the file. The commands
that make up SCCS are admin(1), cdc(1), delta(1), get(1), prs(1),
rmdel(1), sact(1), sccsdiff(1), unget(1), val(1), and what(1).
SCCS file
An ordinary text file that has been modified so the (can be used with
it. This modification is done automatically by the admin(1) command.
See also
secondary prompt
One or more characters that the shell prints on the display, indicating
that more input is needed. This prompt is not encountered nearly as
frequently as the shell's primary prompt (see When it occurs, it is
usually caused by an omitted right quote on a string (which confuses
the shell), or when you enter a shell programming language control-flow
construct (such as a construct) from the command line. By default, the
shell's secondary prompt is the greater-than sign but you can re-define
it by setting the shell variable appropriately in your file. (The C
shell has no secondary prompt.)
semaphore identifier (semid)
A unique positive integer created by a semget(2) system call. Each has
a set of semaphores and a data structure associated with it. The data
structure is referred to as and contains the following members:
Semaphore identifiers can be created using ftok(3C).
is a structure that specifies the semaphore operation permission (see
below). This structure includes the following members:
The value of is equal to the number of semaphores in the set. Each
semaphore in the set is referenced by a positive integer referred to as
a values run sequentially from 0 to the value of sem_nsems minus 1. is
the time of the last semop(2) operation, and is the time of the last
semctl(2) operation that changed a member of the above structure.
semaphore operation permissions
In the semop(2) and semctl(2) system call descriptions, the permission
required for an operation is indicated for each operation. Whether a
particular process has these permissions for an object is determined by
the object's permission mode bits as follows:
Read by user
Alter by user
Read, Alter by group
Read, Alter by others
Read and Alter permissions on a are granted to a process if one or more
of the following are true:
· The process's effective user ID is superuser.
· The process's effective user ID matches in the data structure
associated with and the appropriate bit of the "user" portion
(0600) of is set.
· The process's effective user ID does not match and the appropriate
bit of the "group" portion (060) of is set.
· The process's effective user ID does not match and the process's
effective group ID does not match and neither of is in the
process's group access list and the appropriate bit of the "other"
portion (06) of is set.
Otherwise, the corresponding permissions are denied.
semid
See
session
Each process group is a member of a session. A process is considered
to be a member of the session of which its process group is a member.
A newly created process joins the session of its creator. A process
can alter its session membership (see setsid(2)). A session can have
multiple process groups (see setpgid(2)).
session leader
A process that has created a session (see setsid(2)).
session lifetime
The period between when a session is created and the end of the life‐
time of all process groups that remain as members of the session.
set-group-ID bit
A single bit in the mode of every file in the file system. If a file
is executed whose is set, the of the process which executed the file is
set equal to the of the owner of the file. See also
set-user-ID bit
A single bit in the mode of every file in the file system. If a file
is executed whose is set, the of the process that executed the file is
set equal to the of the owner of the file.
shared library
An executable file that can be shared between several different pro‐
grams. Code from a shared library is not linked into the program by
ld(1), but is instead mapped into the process's address space at run
time by the dynamic loader. Shared libraries must contain position-
independent code, and are created by ld(1). They typically have the
file name suffix
shared memory identifier (shmid)
A unique positive integer created by a shmget(2) system call. Each has
a segment of memory (referred to as a shared memory segment) and a data
structure associated with it. The data structure is referred to as and
contains the following members:
Shared memory identifiers can be created using ftok(3C).
is a structure that specifies the permission for a shmop(2) or shm‐
ctl(2) operation (see below). This structure includes the following
members:
specifies the size of the shared memory segment. is the process id of
the process that created the shared memory identifier. is the process
id of the last process that performed a shmop(2) operation. is the
number of processes that currently have this segment attached. is the
time of the last operation, is the time of the last operation, and is
the time of the last shmctl(2) operation that changed one of the mem‐
bers of the above structure.
shared memory operation permissions
In the shmop(2) and shmctl(2) system call descriptions, the permission
required for an operation is indicated for each operation. Whether a
particular process has the permission to perform a shmop(2) or shm‐
ctl(2) operation on an object is determined by the object's permission
mode bits as follows:
Read by user
Write by user
Read, Write by group
Read, Write by others
Read and Write permissions for a shmop(2) or shmctl(2) operation on a
() are granted to a process if one or more of the following are true:
· The process's effective user ID is superuser.
· The process's effective user ID matches in the data structure
associated with the and the appropriate bit of the "user" portion
(0600) of is set.
· The process's effective user ID does not match and either the
process's effective group ID matches or one of is in the process's
group access list and the appropriate bit of the "group" portion
(060) of is set.
· The process's effective user ID does not match and the process's
effective group ID does not match and neither of is in the
process's group access list and the appropriate bit of the "other"
portion (06) of is set.
Otherwise, the corresponding permissions are denied.
shell
A user interface to the HP-UX operating system. A shell often func‐
tions as both a command interpreter and an interpretive programming
language. A shell is automatically invoked for every user who logs in.
See sh(1) and its related manual entries plus the tutorials supplied
with your system for details.
shell program
See
shell script
A sequence of shell commands and shell programming language constructs
stored in a file and invoked as a user command (program). No compila‐
tion is needed prior to execution because the shell recognizes the com‐
mands and constructs that make up the shell programming language. A
shell script is often called a or a See the
shmid
See
signal
A software interrupt sent to a process, informing it of special situa‐
tions or events. Also, the event itself. See signal(2).
single-user state
A condition of the HP-UX operating system in which the system console
provides the only communication mechanism between the system and its
user. By convention, single-user state is usually specified by
init(1M) as run-level or Do not confuse in which the software is limit‐
ing a multiuser system to a single-user communication, with a single-
user system, which can never communicate with more than one fixed ter‐
minal. See also
slash
The literal character A consisting of a single slash resolves to the of
the process. See also
solidus
See
source code
The fundamental high-level information (program) written in the syntax
of a specified computer language. Object (machine-language) code is
derived from source code. When dealing with an HP-UX shell command
language, is input to the command language interpreter. The term is
synonymous with this meaning. When dealing with the C Language, is
input to the cc(1) command. can also refer to a collection of sources
meeting any of the above conditions.
special file
A file associated with an I/O device. Often called a Special files are
read and written the same as but requests to read or write result in
activation of the associated device. Due to convention and consis‐
tency, these files should always reside in the directory. See also
special system processes
Special system processes are those which are critical to basic system
operation. They include: the scheduler, the initialization process
(also known as and the pager.
SS/80
See
standard error
The destination of error and special messages from a program, intended
to be used for diagnostic messages. The standard error output is often
called and is automatically opened for writing on file descriptor 2 for
every command invoked. By default, the user's terminal is the destina‐
tion of all data written to standard error, but it can be redirected
elsewhere. Unlike standard input and standard output, which are never
used for data transfer in the "wrong" direction, standard error is
occasionally read. This is not recommended practice, since I/O redi‐
rection is likely to break a program doing this.
standard input
The source of input data for a program. The standard input file is
often called and is automatically opened for reading on file descriptor
0 for every command invoked. By default, the user's terminal is the
source of all data read from standard input, but it can be redirected
from another source.
standard output
The destination of output data from a program. The standard output
file is often called and is automatically opened for writing on file
descriptor 1 for every command invoked. By default, the user's termi‐
nal is the destination of all data written to standard output, but it
can be redirected elsewhere.
stderr
See
stdin
See
stdout
See
stream
A term most often used in conjunction with the standard I/O library
routines documented in Section 3 of this manual. A stream is simply a
file pointer (declared as returned by the fopen(3S) library routines.
It may or may not have buffering associated with it (by default,
buffering is assigned, but this can be modified with setbuf(3S)).
sticky bit
A single bit in the mode of every file in the file system. The sticky
bit has no significance if it is set on a
If set on a directory, the files in that directory can be removed or
renamed only by the owner of the file, the owner of the directory con‐
taining the file, or superuser. See also chmod(2), rename(2),
rmdir(2), and unlink(2).
subdirectory
A directory that is one or more levels lower in the file system hierar‐
chy than a given directory. Sometimes called a
subordinate directory
See
Subset 1980
See
superblock
A block on each file system's mass storage medium which describes the
file system. The contents of the superblock vary between implementa‐
tions. Refer to the system administrator manuals supplied with your
system for details.
superuser
The HP-UX system administrator. This user has access to all files, and
can perform privileged operations. has a and of 0, and, by convention,
the user name of
superior directory
See
supplementary group ID
A process has up to supplementary group IDs used in determining file
access permissions, in addition to the effective group ID. The supple‐
mentary group IDs of a process are set to the supplementary group IDs
of the parent process when the process is created. Note that the value
returned from may be larger than the value of found in on certain HP-UX
systems.
symbolic link
A type of file that indirectly refers to a path name. See symlink(4).
system
The HP-UX operating system. See also
system asynchronous I/O
A method of performing I/O whereby a process informs a driver or sub‐
system that it wants to know when data has arrived or when it is possi‐
ble to perform a write request. The driver or subsystem maintains a
set of buffers through which the process performs I/O. See ioctl(2),
read(2), select(2), and write(2) for more information.
system call
An HP-UX operating system kernel function available to the user through
a high-level language (such as FORTRAN, Pascal, or C). Also called an
"intrinsic" or a "system intrinsic." The available system calls are
documented in Section 2 of the
system console
A keyboard and display (or terminal) given a unique status by HP-UX and
associated with the special file All boot ROM error messages, HP-UX
system error messages, and certain system status messages are sent to
the system console. Under certain conditions (such as the single-user
state), the system console provides the only mechanism for communicat‐
ing with HP-UX. See the System Administrator manuals and user guides
provided with your system for details on configuration and use of the
system console.
system process
A is a process that runs on behalf of the system. It may have special
implementation-defined characteristics.
terminal
A that obeys the specifications of termio(7).
terminal affiliation
The process by which a process group leader establishes an association
between itself and a particular terminal. A terminal becomes affili‐
ated with a process group leader (and subsequently all processes cre‐
ated by the process group leader, see whenever the process group leader
executes (either directly or indirectly) an open(2) or creat(2) system
call to open a terminal. Then, the process which is executing open(2)
or creat(2) is a process group leader, and that process group leader is
not yet affiliated with a terminal, and the terminal being opened is
not yet affiliated with a process group, the affiliation is established
(however, see open(2) description of
An affiliated terminal keeps track of its process group affiliation by
storing the process group's process group ID in an internal structure.
Two benefits are realized by terminal affiliation. First, all signals
sent from the terminal are sent to all processes in the terminal group.
Second, all processes in the terminal group can perform I/O to/from the
generic terminal driver which automatically selects the affiliated ter‐
minal.
Terminal affiliation is broken with a terminal group when the process
group leader terminates, after which the hangup signal is sent to all
processes remaining in the process group. Also, if a process (which is
not a process group leader) in the terminal group becomes a process
group leader via the setpgrp(2) system call, its terminal affiliation
is broken.
See and setpgrp(2).
terminal device
See
text file
A file that contains characters organized into one or more lines. The
lines cannot contain NUL characters, and none can exceed bytes in
length including the terminating newline character. Although neither
the kernel nor the C language implementation distinguishes between text
files and binary files (see ANSI C Standard X3-159-19xx), many utili‐
ties behave predictably only when operating on text files.
tty
Originally, an abbreviation for teletypewriter; now, generally, a
upshifting
The conversion of a lowercase character to its uppercase representa‐
tion.
user ID
Each system user is identified by an integer known as a which is in the
range of zero to inclusive. Depending on how the user is identified
with a process, a value is referred to as a an or a
UTC
See
utility
An executable file, which might contain executable object code (that
is, a or a list of to execute in a given order (that is, a You can
write your own utilities, either as executable programs or shell
scripts (which are written in the shell programming language).
volume number
Part of an address used for devices. A number whose meaning is soft‐
ware- and device-dependent, but which is often used to specify a par‐
ticular volume on a multivolume disk drive. See the System Administra‐
tor manuals supplied with your system for details.
whitespace
One or more characters which, when displayed, cause a movement of the
cursor or print head, but do not result in the display of any visible
graphic. The whitespace characters in the ASCII code set are space,
tab, newline, form feed, carriage return, and vertical tab. A particu‐
lar command or routine might interpret some, but not necessarily all,
whitespace characters as delimiters for fields, words, or command
options.
working directory
Each process has associated with it the concept of a current working
directory. For a shell, this appears as the directory in which you
currently "reside". This is the directory in which relative path name
(that is, a path name that does not begin with searches begin. It is
sometimes referred to as the or the
zombie process
The name given to a process which terminates for any reason, but whose
parent process has not yet waited for it to terminate (via wait(2)).
The process which terminated continues to occupy a slot in the process
table until its parent process waits for it. Because it has termi‐
nated, however, there is no other space allocated to it either in user
or kernel space. It is therefore a relatively harmless occurrence
which will rectify itself the next time its parent process waits. The
ps(1) command lists zombie processes as
SEE ALSOintroduction(9).
glossary(9)