glossary.9 (2010 09)

c
glossary(9) glossary(9)
current directory
See working directory.
current working directory
See working directory.
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 daemon. It exists to perform these functions for line printer jobs queued by lp (1). An
example of a permanent daemon (that is, one that should never die) is cron(1M).
data encryption
A method for encoding information in order to protect sensitive or proprietary 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
., /,
0-9, A-Z, a-z. 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 slash (
/)). It is defined
by the environment variable
PATH (see environ (5)). login (1) sets PATH equal to :/usr/bin, which
means that your working directory is the first directory searched, followed by /usr/bin. The search
path can be redefined by modifying the value of PATH. This is usually done in
/etc/profile,and/or
in the
.profile file found in the home directory.
defunct process
See zombie process.
delta
A term used in the Source Code Control System (SCCS) to describe a unit of one or more textual
changes to an SCCS file. Each time an SCCS file is edited, changes made to the file are stored separately
as a delta. 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
vi or ed editor, which
incorporates changes into the file immediately, eliminating any possibility of obtaining a previous version
of that file. A similar capability is provided by RCS files (see rcsintro (5)).
demon
Improper spelling of the UNIX word daemon.
device
A computer peripheral or an object that appears to an application as such.
device address
See bus address.
device file
See special file.
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 inode; The pointer is called a link. A file can have several links appearing anywhere on the
same file system. Each user is free to create as many directories as needed (using mkdir (1)), provided
that the parent directory 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 dot and dot-dot respec-
tively. . refers to the directory itself and .. refers to its parent directory. A directory containing only
. and .. is considered empty.
HP-UX 11i Version 3: September 2010 − 5 − Hewlett-Packard Company 5