glossary.9 (2010 09)

d
glossary(9) glossary(9)
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’s address space. The
dynamic loader also resolves symbolic references between a program and the shared libraries, and initial-
izes the shared libraries’ linkage tables. See dld.sl (5) (PA-RISC systems) or dld.so (5) (Itanium-based
systems) for details.
effective group ID
Every process has an effective group ID that is used to determine file access permissions.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 per-
missions 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 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
root, such as mkdir and mail, 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 real user ID and set-user-ID bit.
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 Ctrl-D.
(3) A character defined by stty (1) or ioctl (2) (see termio(7)) to act as end-of-file on your terminal. Usu-
ally this is Ctrl-
D.
(4) The return value from read(2) that indicates end of data.
environment
The set of defined shell variables (such as EXINIT, HOME, PATH, SHELL, TERM, and others) that define
the conditions under which user commands run. These conditions can include user terminal characteris-
tics, home directory, and default search path. Each shell variable setting in the current process is passed
on to all child processes that are created, provided that each shell variable setting has been exported
via the export command (see sh(1)). Unexported shell variable settings are meaningful only to the
current process, and any child processes created get the default settings of certain shell variables by
6 Hewlett-Packard Company − 6 − HP-UX 11i Version 3: September 2010