HP 748 Owner's Manual page 149

Glossary
root directory The highest level direc-
tory of the hierarchical file system, from
which all other files branch. In HP-UX,
the slash (/) character refers to the "root
directory." The root directory is the only
directory in the file system that is its own
"parent directory."
root file system The file system
mounted on the cluster server.
root server The node in a cluster to
which the storage device containing the
root file system of the cluster is physical-
ly attached. Also ++cluster server++.
root user The user with root permis-
sion, having a separate "root" account
and password.
run-level The system state determined
at boot which defines, among other
things, multi- or single-user status.
SAM System Administration Manager.
A subsystem of HP-UX that does a wide
range of system administration tasks in-
teractively.
script A file that contains commands
that a shell can interpret and run.
SCSI Small Computer System Inter-
face.
server A computer program that pro-
vides file access, login access, file trans-
fer, printing and other services across a
network. Sometimes, but not always, a
server consists of a dedicated computer.
shell An HP-UX command interpreter
(Bourne, Korn, Key, Posix or C), provid-
ing a working environment interface for
the user. The shell takes command input
from the keyboard and interprets it for
the operating system. See Shells: User's
Guide for information on the characteris-
tics of the various shells.
shell script A file that contains com-
mands that a shell can interpret and run.
Also "shell program."
shut down To take the system from
multi-user state to a state in which no
processes are running, using the shut-
down command.
single-user state The state of a com-
puter where there is little or no process
activity and no users logged in. The sys-
tem is only accessible to the current sys-
tem administrator (root). This mode is
brought about by execution of shut-
down(1). Also called 'single-user mode'.
SPU System Processing Unit. The in-
struction- and graphics-processing mod-
ule of the computer (in this case, the
Model 743 board computer), containing
the CPU and I/O processors. Also called
the "SPU module".
standard error The destination of er-
ror and special messages from a pro-
gram, intended to be used for diagnostic
messages. The standard error output is
often called stderr, and is automatically
opened by the shell for writing on file de-
scriptor 2 for every command invoked.
Standard error usually appears on the
display unless it is directed otherwise.
standard input The source of input
Glossary-5