HP-UX Reference (11i v2 03/08) - 5 Miscellaneous Topics, 7 Device (Special) Files, 9 General Information, Index (vol 9)

f
glossary(9) glossary(9)
file pointer A data element obtained through any of the fopen(3S) standard I/O library routines that
‘‘points to’’ (refers to) a file opened for reading and/or writing, and which keeps track of
where the next I/O operation will take place in the file (in the form of a byte offset rela-
tive to the beginning of the file). After obtaining the file pointer, it must thereafter be
used to refer to the open file when using any of the standard I/O library routines. (See
stdio(3S) for a list of these routines.)
file serial number
A file-system-unique identifier for a given file, also known as the file’s inode number.
Each file serial number identifies exactly one inode. File serial numbers are not
necessarily unique across file systems in the file hierarchy.
file status flags
Part of an open file description. These flags can be used to modify the behavior of sys-
tem calls that access the file described by the open file description.
file system A collection of files and supporting data structures residing on a mass storage volume. A
file system provides a name space for file serial numbers referring to those files. Refer
to the System Administrator manuals supplied with your system for details concerning
file system implementation and maintenance.
file times update
Each file has three associated time values that are updated when file data is accessed or
modified, or when the file status is changed. These values are returned in the file charac-
teristics structure, as described in
<sys/stat.h>. For each function in HP-UX that
reads or writes file data or changes the file status, the appropriate time-related files are
noted as ‘‘marked-for-update’’. When an update point occurs, any marked fields are set to
the current time and the update marks are cleared. One such update point occurs when
the file is no longer open for any process. Updates are not performed for files on read-
only file systems.
filter A command that reads data from the standard input, performs a transformation on the
data, and writes it to the standard output.
foreground process group
Each session that has established a connection with a controlling terminal has exactly
one process group of the session as a foreground process group of that controlling termi-
nal. The foreground process group has certain privileges when accessing its controlling
terminal that are denied to background process groups. See read(2) and write(2).
foreground process group ID
The process group ID of the foreground process group.
fork An HP-UX system call (see fork(2)), which, when invoked by an existing process, causes a
new process to be created. The new process is called the child process; the existing pro-
cess is called the parent process. The child process is created by making an exact copy
of the parent process. The parent and child processes are able to identify themselves by
the value returned by their corresponding fork call (see fork(2) for details).
function number
On Series 700 systems, when two or more interfaces reside on a single interface card,
each interface is treated as a separate function and is assigned a corresponding unique
function number.
graphic character
A character other than a control character that has a visual representation when hand-
written, printed, or displayed.
group See group ID.
group ID Associates zero or more users who must all be permitted to access the same set of files.
The members of a group are defined in the files
/etc/passwd and
/etc/logingroup (if it exists) via a numerical group ID that must be between zero
and UID_MAX, inclusive. Users with identical group IDs are members of the same
group. An ASCII group name is associated with each group ID in the file /etc/group.
A group ID is also associated with every file in the file hierarchy, and the mode of each
file contains a set of permission bits that apply only to this group. Thus, if you belong to
a group that is associated with a file, and if the appropriate permissions are granted to
HP-UX 11i Version 2: August 2003 − 8 − Hewlett-Packard Company Section 9−−9