HP-UX Reference (11i v1 05/09) - 7 Device (Special) Files, 9 General Information, Index (vol 10)

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glossary(9) glossary(9)
system asynchronous I/O
A method of performing I/O whereby a process informs a driver or subsystem that it wants to know when
data has arrived or when it is possible 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 HP-UX Reference.
system console
A keyboard and display (or terminal) given a unique status by HP-UX and associated with the special file
/dev/console . 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 communicating with HP-UX. See the System Adminis-
trator manuals and user guides provided with your system for details on configuration and use of the sys-
tem console.
system process
A system process is a process that runs on behalf of the system. It may have special implementation-
defined characteristics.
terminal
A character special file 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 ter-
minal. A terminal becomes affiliated with a process group leader (and subsequently all processes created by
the process group leader, see terminal group) whenever the process group leader executes (either directly
or indirectly) an open(2) or creat(2) system call to open a terminal. Then, if the process which is executing
open(2) or creat(2) is a process group leader, and if that process group leader is not yet affiliated with a ter-
minal, and if the terminal being opened is not yet affiliated with a process group, the affiliation is esta-
blished (however, see open(2) description of
O_NOCTTY).
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 /dev/tty, which automatically selects the affiliated terminal.
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 process group, process group leader, terminal group, and setpgrp(2).
terminal device
See terminal.
text file
A file that contains characters organized into one or more lines. The lines cannot contain NUL characters,
and none can exceed
LINE_MAX 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 utilities behave predictably only when operating on text files.
tty
Originally, an abbreviation for teletypewriter; now, generally, a terminal.
upshifting
The conversion of a lowercase character to its uppercase representation.
HP-UX 11i Version 1: September 2005 − 24 − Hewlett-Packard Company Section 9−−25