HP-UX Reference (11i v2 03/08) - 5 Miscellaneous Topics, 7 Device (Special) Files, 9 General Information, Index (vol 9)
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glossary(9) glossary(9)
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 particu-
lar 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.Afile
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 direc-
tory 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 respectively. Dot refers to the directory itself and dot-dot refers to its parent
directory. A directory containing only
. and .. is considered empty.
dot See
. (dot).
dot-dot See
.. (dot-dot).
dot-oh See
.o (dot-oh).
dot-oh file See
.o (dot-oh).
dot-oh format See
.o (dot-oh).
downshifting The conversion of an uppercase character to its lowercase representation.
dynamic loader
A routine invoked at process startup time that loads shared libraries into a process’
address space. The dynamic loader also resolves symbolic references between a program
and the shared libraries, and initializes the shared libraries’ linkage tables. See dld.sl(5)
(PA-RISC systems) or dld.so(5) (Itanium(R)-based systems) for details.
effective group ID
Every process has an effective group ID that is used to determine file access permis-
sions. A process’s effective group ID is determined 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
mode), the process’s effective group ID 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 effective group ID is inherited from the
process’s parent. The setting of the process’s effective group ID 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 group, real group ID, and set-group-ID bit.
effective user ID
A process has an effective user ID that is used to determine file access permissions
(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
mode), the process’s effective user ID is set equal to the file’s user ID. This makes the
Section 9−−6 Hewlett-Packard Company − 5 − HP-UX 11i Version 2: August 2003