• RADIUS
  Remote Authentication Dial-In user Service. A standard for authentication and accounting, RADIUS is primarily used to control dial-up access to PPP and other services. The protocal was standardized in RFC 2058, the current implementation is defined in RFCs 2138 and 2139. RADIUS uses UDP packets, older servers use ports 1645 and 1646, the current standard is port 1812 for authentication and 1813 for accounting
   
• RAID
  Redundant Array of Inexpensive Disks - a method whereby information is spread across several disks, using techniques such as disk striping (RAID Level 0) and disk mirroring (RAID level 1) to achieve redundancy, lower latency and/or higher bandwidth for reading and/or writing, and recoverability from hard-disk crashes
   
• raw mode
  A mode in which characters entered into the Linux system are read and interpreted one at a time
   
• Raymond, Eric
  a software developer who has written a number of important Open Source programs including fetchmail and sed. Eric also maintains 8 FAQs, amd has written a number of influential papers including The Cathedral and the Bazaar: an analysis of how and why the Linux development model works
   
• rc file
  Script file containing startup instructions for an application program (or an entire operating system), usually a text file containing commands of the sort that might have been invoked manually once the system was running but are to be executed automatically each time the system starts up
   
• RCS
  the revision control system, is a suite of programs that tracks changes in text files and controls shared access to files in work group situations. It is generally used to maintain source code modules
   
• rdev
  A utility which can be used to obtain information about your Linux system. It can query/set the image root device, the swap device, the RAM disk size or video mode.
   
• read-only
  A file that can be read (copied, and so on) but not written (changed). Linux has a system of permissions that enables the owner of the file, the owner's group, or all users to have or not have permission to read, write, or execute file
   
• README
  A roadmap of your source distribution. By ancient convention, this is the first file intrepid explorers will read after unpacking the source.
   
• Real time OS
  a real-time operating system is able to execute all of its tasks without violating specified timing constraints
   
• redirection
  Accepting input from a source other than the standard input or sending output to a destination other than the standard output. Use the less than sign (<) for redirection of input and the greater than sign (>) for redirection of output.
   
• regexp
  See regular expression.
   
• regular expression
  A set of symbols, including text and metacharacters, used to search for text. The most common components are the period (.), which matches one character; the asterisk (*), which matches any number of characters; and brackets ([string]), which list a set of characters to be matched
   
• Relational Database
  A database that is organized and accessed according to relationships between data items
   
• remote login
  Logging in to another computer from your own computer. This process requires that your computer be on a network or have a phone connection
   
• RFC
  Request for Comments - Standards that define the Internet and how it operates. RFC also refers to the way these documents are discussed and approved by the Internet community
   
• RFS
  Remote File Sharing. Like NFS, a program that lets you treat files on another computer in more or less the same way as you treat files on your own computer
   
• rlogin
  Rlogin starts a terminal session on a remote host.
   
• rm
  removes each given file. By default, it does not remove directories.
   
• rmdir
  removes empty directories.
   
• Rockridge extensions
  They are an add-on to the traditional ISO 9660 format. These extensions are necessary to handle the long file names and deeply nested directories frequently used in Linux programs.
   
• root window
  the background of your screen. It is referred to a window in name alone, it does not behave like any other window, but rather you run your applications on the root window, or put a picture on it, or just a solid color
   
• Router
  A special-purpose computer (or software package) that handles the connection between 2 or more networks. Routers spend their time looking at the destination addresses of the packets passing through them and deciding which route to send them on
   
• RPC
  Remote Procedure Call. RPC routines allow C programs to make procedure calls on other machines across the network. When people talk about RPC they most often mean the Sun RPC variant
   
• RPG
  Report Program Generator - A system produced by IBM in 1965 for easy production of sophisticated large system reports
   
• RPM
  Red Hat Package Manager - an open packaging system
   
• RS-232C
  A standard for serial communication that is used to connect computers, terminals, printers, and modems. The complete standard calls for 25 wires, but many configurations use as few as three (send, receive, and ground)
   
• runlevel
  The groups of processes which are started by init are controlled by the runlevel. The runlevel is a digit from 0 to 6 or the letter S. Runlevels 0, 6 and S are reserved for shutdown, reboot and single user mode. Runlevel 1 is also single user mode

Key:  Commands - People - General

Last Updated Saturday, December 04 2004 @ 11:13 AM EST