Linux dictionary

Linux Dictionary Version 0.16 Author: Binh Nguyen <linuxfilesystem(at)yahoo(dot)com(dot)au> 2004−08−16 This document is designed to be a resource for those Linux users wishing to seek clarification on Linux/UNIX/POSIX related terms and jargon. At approximately 24000 definitions and two thousand pages it is one of the largest Linux related dictionaries currently available. Due to the rapid rate at which new terms are being created it has been decided that this will be an active project. We welcome input into the content of this document. At this moment in time half yearly updates are being envisaged. Please note that if you wish to find a 'Computer Dictionary' then see the 'Computer Dictionary Project' at http://computerdictionary.tsf.org.za/ Searchable databases exist at locations such as: http://www.swpearl.com/eng/scripts/dictionary/ (SWP) Sun Wah−PearL Linux Training and Development Centre is a centre of the Hong Kong Polytechnic University, established in 2000. Presently SWP is delivering professional grade Linux and related Open Source Software (OSS) technology training and consultant service in Hong Kong. SWP has an ambitious aim to promote the use of Linux and related Open Source Software (OSS) and Standards. The vendor independent positioning of SWP has been very well perceived by the market. Throughout the last couple of years, SWP becomes the Top Leading OSS training and service provider in Hong Kong. http://www.geona.com/dictionary?b= Geona, operated by Gold Vision Communications, is a new powerful search engine and internet directory, delivering quick and relevant results on almost any topic or subject you can imagine. The term "Geona" is an Italian and Hebrew name, meaning wisdom, exaltation, pride or majesty. We use our own database of spidered web sites and the Open Directory database, the same database which powers the core directory services for the Web's largest and most popular search engines and portals. Geona is spidering all domains listed in the non−adult part of the Open Directory and millions of additional sites of general interest to maintain a fulltext index of highly relevant web sites. http://www.linuxdig.com/documents/dictionary.php LINUXDIG.COM, "Yours News and Resource Site", LinuxDig.com was started in May 2001 as a hobby site with the original intention of getting the RFC's online and becoming an Open Source software link/download site. But since that time the site has evolved to become a RFC distribution site, linux news site and a locally written technology news site (with bad grammer :)) with focus on Linux while also containing articles about anything and everything we find interesting in the computer world. LinuxDig.Com contains about 20,000 documents and this number is growing everyday! http://linux.about.com/library/glossary/blglossary.htm Each month more than 20 million people visit About.com. Whether it be home repair and decorating ideas, recipes, movie trailers, or car buying tips, our Guides offer practical advice and solutions for every day life. Wherever you land on the new About.com, you'll find other content that is relevant to your interests. If you're looking for "How To" advice on planning to re−finish your deck, we'll also show you the tools you need to get the job done. If you've been to About before, we'll show you the latest updates, so you don't see the same thing twice. No matter where you are on About.com, or how you got here, you'll always find content that is relevant to your needs. Should you wish to possess your own localised searcheable version please make use of the available "dict", http://www.dict.org/ version at the Linux Documentation Project home page, http://www.tldp.org/ The author has decided to leave it up to readers to determine how to install and run it on their specific systems. An alternative form of the dictionary is available at: http://elibrary.fultus.com/covers/technical/linux/guides/Linux−Dictionary/cover.html Fultus Corporation helps writers and companies to publish, promote, market, and sell books and eBooks. Fultus combines traditional self−publishing practices with modern technology to produce paperback and hardcover print−on−demand (POD) books and electronic books (eBooks). Fultus publishes works (fiction, non−fiction, science fiction, mystery, ) by both published and unpublished authors. We enable you to self−publish easily and cost−effectively, creating your book as a print−ready paperback or hardcover POD book or as an electronic book (eBook) in multiple eBook's formats. You retain all rights to your work. We provide distribution to bookstores worldwide. And all at a fraction of the cost of traditional publishing. We also offer corporate publishing solutions that enable businesses to produce and deliver manuals and documentation more efficiently and economically. Our use of electronic delivery and print−on−demand technologies reduces printed inventory and saves time. Please inform the author as to whether you would like to create a database or an alternative form of the dictionary so that he can include you in this list. Also note that the author considers breaches of copyright to be extremely serious. He will pursue all claims to the fullest extent of the law. Copyright 2003 Binh Nguyen Trademarks are owned by their owners. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2; with no Invariant Sections, with no Front−Cover Texts, and with no Back−Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". Table of Contents Source and pre−formatted versions available 1 Chapter 1. Linux Dictionary 2 Punctuation 3 A 204 B 295 C 355 D 453 E 547 F 597 G 655 H 736 I 770 J 841 K 859 L 896 M 973 N 1066 O 1120 P 1157 Q 1266 R 1275 S 1341 T 1489 Linux Dictionary i Table of Contents U 1566 V 1597 W 1631 X 1671 Y 1727 Z 1733 Appendix A. About the Author 1740 Appendix B. Contributors 1741 Appendix C. Disclaimer 1742 Appendix D. Donations 1743 Appendix E. Feedback 1744 Bibliography 1745 Appendix F. GNU Free Documentation License 1752 F.1. PREAMBLE 1752 F.2. APPLICABILITY AND DEFINITIONS 1752 F.3. VERBATIM COPYING 1753 F.4. COPYING IN QUANTITY 1754 F.5. MODIFICATIONS 1754 F.6. COMBINING DOCUMENTS 1755 F.7. COLLECTIONS OF DOCUMENTS 1756 F.8. AGGREGATION WITH INDEPENDENT WORKS 1756 F.9. TRANSLATION 1756 F.10. TERMINATION 1757 F.11. FUTURE REVISIONS OF THIS LICENSE 1757 F.12. ADDENDUM: How to use this License for your documents 1757 Linux Dictionary ii Source and pre−formatted versions available The source code and other machine readable formats of this book can be found on the Internet at the Linux Documentation Project home page http://www.tldp.org/ The latest version of this document can be found at http://cvsview.tldp.org/index.cgi/LDP/guide/docbook/Linux−Dictionary/ Source and pre−formatted versions available 1 Chapter 1. Linux Dictionary Chapter 1. Linux Dictionary 2 Punctuation $BASH environment variable Expands to the full pathname used to invoke this instance of bash. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $BASH_VERSION environment variable Expands to the version number of this instance of bash. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $CDPATH environment variable The search path for the cd command. This is a colon−separated list of directories in which the shell looks for destination directories specified by the cd command. A sample value is ``.:~:/usr''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $ENV environment variable If this parameter is set when bash is executing a shell script, its value is interpreted as a filename containing commands to initialize the shell, as in .bashrc. The value of ENV is subjected to parameter expansion, command substitution, and arithmetic expansion before being interpreted as a pathname. PATH is not used to search for the resultant pathname. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $FIGNORE environment variable A colon−separated list of suffixes to ignore when performing filename completion (see READLINE below). A filename whose suffix matches one of the entries in FIGNORE is excluded from the list of matched filenames. A sample value is ``.o:~''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HISTCMD environment variable The history number, or index in the history list, of the current command. If HISTCMD is unset, it loses its special properties, even if it is subsequently reset. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HISTCONTROL environment variable If set to a value of ignorespace, lines which begin with a space character are not entered on the history list. If set to a value of ignoredups, lines matching the last history line are not entered. A value of ignoreboth combines the two options. If unset, or if set to any other value than those above, all lines read by the parser are saved on the history list. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HISTFILE environment variable The name of the file in which command history is saved. (See HISTORY below.) The default value is ~/.bash_history. If unset, the command history is not saved when an interactive shell exits. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HISTFILESIZE environment variable The maximum number of lines contained in the history file. When this variable is assigned a value, the history file is truncated, if necessary, to contain no more than that number of lines. The default value is 500. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HISTSIZE environment variable The number of commands to remember in the command history (see HISTORY below). The default value is 500. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HOME environment variable The home directory of the current user; the default argument for the cd builtin command. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HOSTFILE Contains the name of a file in the same format as /etc/hosts that should be read when the shell needs to complete a hostname. The file may be changed interactively; the next time hostname completion is Punctuation 3 attempted bash adds the contents of the new file to the already existing database. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $HOSTTYPE Automatically set to a string that uniquely describes the type of machine on which bash is executing. The default is system−dependent. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $IFS In UNIX, the $IFS variable separates commands. It is usually conigured to be the semicolon (;) and newline characters. However, it can be reconfigured to be other characters as well. Data−driven attacks will sometimes seek to reset the IFS variable (e.g. IFS=x), then cause execution within the data field wihtout having to insert shell metacharacters. Tidbit: On Linux, the $FF variable may also be used like $IFS. From Hacking−Lexicon http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $IFS The Internal Field Separator that is used for word splitting after expansion and to split lines into words with the read builtin command. The default value is ``<space><tab><newline>''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $IGNOREEOF Controls the action of the shell on receipt of an EOF character as the sole input. If set, the value is the number of consecutive EOF characters typed as the first characters on an input line before bash exits. If the variable exists but does not have a numeric value, or has no value, the default value is 10. If it does not exist, EOF signifies the end of input to the shell. This is only in effect for interactive shells. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $INPUTRC environment variable The filename for the readline startup file, overriding the default of ~/.inputrc (see READLINE below). From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $LINENO Each time this parameter is referenced, the shell substitutes a decimal number representing the current sequential line number (starting with 1) within a script or function. When not in a script or function, the value substituted is not guaranteed to be meaningful. When in a function, the value is not the number of the source line that the command appears on (that information has been lost by the time the function is executed), but is an approximation of the number of simple commands executed in the current function. If LINENO is unset, it loses its special properties, even if it is subsequently reset. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $MAIL If this parameter is set to a filename and the MAILPATH variable is not set, bash informs the user of the arrival of mail in the specified file. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $MAILCHECK Specifies how often (in seconds) bash checks for mail. The default is 60 seconds. When it is time to check for mail, the shell does so before prompting. If this variable is unset, the shell disables mail checking. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $MAILPATH A colon−separated list of pathnames to be checked for mail. The message to be printed may be specified by separating the pathname from the message with a `?'. $_ stands for the name of the current mailfile. Example: MAILPATH='/usr/spool/mail/bfox?"You have mail":~/shell−mail?"$_ has mail!"' Bash supplies a default value for this variable, but the location of the user mail files that it uses is system dependent (e.g., /usr/spool/mail/$USER). From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $MAIL_WARNING Linux Dictionary Punctuation 4 If set, and a file that bash is checking for mail has been accessed since the last time it was checked, the message ``The mail in mailfile has been read'' is printed. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $OLDPWD The previous working directory as set by the cd command. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $OSTYPE Automatically set to a string that describes the operating system on which bash is executing. The default is system−dependent. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PATH The search path for commands. It is a colon−separated list of directories in which the shell looks for commands (see COMMAND EXECUTION below). The default path is system−dependent, and is set by the administrator who installs bash. A common value is ``/usr/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin:.''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PATH The shell looks for commands and programs in a list of file paths stored in the PATH environment variable. An environment variable stores information in a place where other programs and commands can access it. Environment variables store information such as the shell that you are using, your login name, and your current working directory. To see a list of all the environment variables currently defined; type 'set' at the prompt. When you type a command at the shell prompt, the shell will look for that command's program file in each directory listed in the PATH variable, in order. The first program found matching the command you typed will be run. If the command's program file is not in a directory listed in you PATH environment variable, the shell returns a "commands not found" error. By default, the shell does not look in your current working directory or your home directory for commands This is really a security mechanism so that you don't execute programs by accident. What if a malicious user put a harmful program called ls in your home directory? If you typed ls and the shell looked for the fake program in your home directory before the real program in the /bin directory, what do you think woul dhappen? If you thought bad things, you are on the right track. Since your PATH doesn't have the current directory as one of its search locations, programs in your current directory must be called with an absolute path of a relative path specified as './program−name'. To see what directories are part of your PATH enter this command: # echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11 From Complete−Idiot's Guide to Linux http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PROMPT_COMMAND If set, the value is executed as a command prior to issuing each primary prompt. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PS1 The value of this parameter is expanded (see PROMPTING below) and used as the primary prompt string. The default value is ``bash\$ ''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PS2 The value of this parameter is expanded and used as the secondary prompt string. The default is ``> ''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PS3 The value of this parameter is used as the prompt for the select command (see SHELL GRAMMAR above). From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PS4 The value of this parameter is expanded and the value is printed before each command bash displays during an execution trace. The first character of PS4 is replicated multiple times, as necessary, to Linux Dictionary Punctuation 5 indicate multiple levels of indirection. The default is ``+ ''. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $PWD The current working directory as set by the cd command. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $RANDOM Each time this parameter is referenced, a random integer is generated. The sequence of random numbers may be initialized by assigning a value to RANDOM. If RANDOM is unset, it loses its special properties, even if it is subsequently reset. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $SECONDS Each time this parameter is referenced, the number of seconds since shell invocation is returned. If a value is assigned to SECONDS. the value returned upon subsequent references is the number of seconds since the assignment plus the value assigned. If SECONDS is unset, it loses its special properties, even if it is subsequently reset. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html $SHLVL Incremented by one each time an instance of bash is started. From Rute−Users−Guide http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .#01 and higher A method of numbering picture files for a roll of film that has been scanned for computer presentation From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .$$$ Used by OS/2 to keep track of archived files From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .(Pagis) native format From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .000 Data file (GEOWorks) From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .000−20009 Used to number old (backup) versions of files (for example, CONFIG.SYS when changed by an installation program); also used to number From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .001−999 Database index files used by (Superbase) From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .1−STEP Backup file (Iomega Backup) From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .113 Backup data file (Iomega Backup) From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .123 Lotus 123 97 file From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .12M Smartmaster file (Lotus 1−2−3 '97) From Whatis−Extensions http://www.tldp.org/LDP/Linux−Dictionary/html/index.html .1ST Linux Dictionary Punctuation 6 [...]... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html A Punctuation 7 Linux Dictionary Object code library From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html A3L Authorware 3.x library From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html A3M Authorware MacIntosh file (unpackaged) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ABK Corel Draw AutoBackup From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ABM Punctuation 8 Linux Dictionary Audio album file (HitPlayer) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ABO Applix Builder Turbo file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AE Author/Editor file (SoftQuad) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AEP ArcExplorer project file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html Punctuation 11 Linux Dictionary AF2 ABC FlowCharter 2.0 Flowchart From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AMG ACTOR System image From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AMG AMGC Compressed archive From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AMI Annotation file (Cocreate SolidDesigner) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html Punctuation 13 Linux Dictionary. .. http://www.tldp.org/LDP /Linux Dictionary/ html/index.html APD Lotus 1−2−3 Printer driver From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html Punctuation 14 Linux Dictionary APF Lotus 1−2−3 Printer driver From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html APF Project file (Allaire) (Created by Homesite) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html Punctuation 16 Linux Dictionary ART First Publisher Raster graphic From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ART Ray Tracer file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ART Xara Studio drawing From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ASF Microsoft Advanced Streaming Format From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ASF Music file (Electronic Arts) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html ASF Punctuation 17 Linux Dictionary StratGraphics Datafile From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AVS Stardent AVS−X Image From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AVX File Extension (ArcView) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AW Applix Words file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html AW Punctuation 19 Linux Dictionary HP AdvanceWrite... Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BAD Punctuation 20 Linux Dictionary Oracle bad file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BAK Backup file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BAL Ballade Music score From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BAR dBase... http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BCW Borland C++ 4.5 Environment settings file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BDB Microsoft Works Dababase file From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BDF Egret Datafile From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html BDF Punctuation 21 Linux Dictionary . at http://cvsview.tldp.org/index.cgi/LDP/guide/docbook /Linux Dictionary/ Source and pre−formatted versions available 1 Chapter 1. Linux Dictionary Chapter 1. Linux Dictionary 2 Punctuation $BASH environment. Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html .12M Smartmaster file (Lotus 1−2−3 '97) From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html .1ST Linux Dictionary Punctuation. Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html .A Linux Dictionary Punctuation 7 Object code library From Whatis−Extensions http://www.tldp.org/LDP /Linux Dictionary/ html/index.html .A3L Authorware