R
raw mode
The condition of a device driver in which the driver does not interpret the data
passing through it. For example, a UNIX terminal driver operating in raw mode
passes a Return character from the terminal directly to the system.
See also cooked mode
raw socket
A socket that provides privileged users access to internal network protocols and
interfaces. These socket types can be used to take advantage of protocol features
not available through more normal interfaces or to communicate with hardware
interfaces.
rc
An element of the name applied to files containing command scripts that control
the process of booting a computer. The rc characters are also used in the names
of files that contain user-customized startup information, such as the BSD mail
utility .mailrc and the Motif window manager .mwmrc.
RCS (Revision Control System)
A set of programs for managing program and documentation source files so that
any revision of a given file can be retrieved. Revisions to a file are stored as a
series of incremental changes (deltas) applied to the original version instead of as
complete copies of all the versions. The system provides locking mechanisms so
that only a single user can apply changes to a given file at any one time.
See also SCCS (Source Code Control System)
RCS file
A file stored in the Revision Control System (RCS) library containing the text of the
original file and the list of deltas that have been applied to it.
RCS library
The directory in which Revision Control System (RCS) files are stored.
record
1. A collection of related data items treated as a unit. A record contains one or
more fields.
2. In awk, the information between two consecutive occurrences of the record
separator. For most purposes, a record in awk can be thought of as a line from
the input file.
recursive
In programming, pertaining to a procedure or function that accomplishes its task
by repeatedly calling itself until a specified condition is reached. The process of
using a recursive procedure or function is called recursion.
redirection
The specifying of one or more of the devices with which the standard input,
standard output, and standard error virtual files are to be associated during the
execution of a given command.
reference page
One of a collection of files containing documentation on all commands, system
calls, library routines, and so forth. Reference pages are often called manual
pages or man pages. For information about reference pages, see Chapter 4.
regular expression
A pattern of one or more characters used to find text information and formed
according to a set of rules that define how the characters are to be interpreted.
For example, a period is interpreted as a valid match for any character in the
input. The regular expression a.c matches any string containing the letter a and
the letter c separated by a single intervening character, such as abc, a?c, a9c, and
so on.
See also pattern matching
relative pathname
A pathname that begins at the user's working directory; they are written without
the initial slash. For example, docs/myfile.txt is a relative pathname.
See also absolute pathname
restricted shell
A security feature that provides a controlled shell environment with limited
features.
Revision Control System
See RCS (Revision Control System)
RIS (Remote Installation Services)
A utility for installing software kits across a network instead of by using locally
mounted distribution media.
RIS area
A reserved disk area physically connected to a RIS server, containing one or more
product environments in which are stored installable software kits.
RIS client
A computer system that has permission to install software across the network by
accessing kits stored in the server's RIS area.
RIS server
A computer system that serves other computers by providing software kits for
them to install. The software is stored on disks belonging to the server and is
accessed across the network by the RIS clients.
RISC (Reduced Instruction Set Computing)
A computer architecture that is based on a limited set of simple instructions
instead of a larger and more varied set of more complex instructions.
root
1. The login name for the superuser (system administrator).
2. The name applied to the topmost directory in the UNIX system's tree-like file
structure; hence, the beginning of an absolute pathname. The root directory is
represented in pathnames by an initial slash (/); a reference to the root directory
itself consists of a single slash.
See also pathname
root directory
See root
root file system
The basic file system, onto which all other file systems can be mounted. The root
file system contains the operating system files that get the rest of the system
running.
root login
See root
routing daemon
A program that provides a routing-management service. The routing daemon,
routed, is invoked when the system is booted to manage the network routing
tables.
See also daemon
run time
Pertaining to actions that are taken by a program or system during execution. See also compile time
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