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APPENDIX A GLOSSARY OF LINUX TERMS PPP Point-to-Point Protocol; networking technology that allows data transfer across serial connections like telephone lines. In other words, it s the technology that lets you connect to your Internet service provider using a modem. process The way the system refers to the individual programs (or components of programs) running in memory. proprietary Effectively, software for which a software license must be acquired, usually for a fee. This usually means the source code is kept secret, but it can also indicate that the source code is available to view but not to incorporate into your own projects or share with others. R Red Hat Well-known company that produces distributions of Linux. redirect To send the output of a command into a particular file. This also works the other way around: the contents of a particular file can be directed into a command. Redirection is achieved within the shell using the left and right angle brackets (< and >), respectively. regex See regular expression. regular expression Powerful and complex method of describing a search string, usually when searching with tools such as grep (although regular expressions are also used when programming). Regular expressions use various symbols as substitutes for characters or to indicate patterns. remote

506 APPENDIX A GLOSSARY OF LINUX TERMS NFS Network File System; reliable and established method of sharing files, printers, and other resources across a network of Unix-based operating systems. See also Samba. NTFS NT File System; file system offered by Windows NT, 2000, and XP. It can be read by Linux, but usually writing is prohibited because it is considered unsafe. See also FAT32. O OpenOffice.org Open Source office suite project created with the continuing input of Sun Microsystems and based on code Sun contributed to the Open Source community. Its commercial release is in the form of Star Office (although Star Office has several proprietary components added). open source (1) Method and philosophy of developing software whereby the source code the original listing created by the programmer is available for all to see. Note that open source is not the same as Free Software; describing software as open source doesn t imply that the code can be shared or used by others (although this is often the case). (2) A community of users or any project that adheres to open-source values and/or practices. P partition Subdivision of a hard disk into which a file system can be installed. PID Process ID; the numbering system used to refer to a process. pipe Method of passing the output from one command to another for further processing. Piping is achieved within the shell by typing the | symbol. POSIX Portable Operating System Interface; various technical standards that define how Unix-like operating systems should operate and to which the Linux operating system attempts to adhere.

APPENDIX A GLOSSARY OF LINUX TERMS localhost (1) Network name used internally by Linux and software to refer to the local computer, distinct from the network. (2) Default name given to a Linux-based PC when no other name is defined during installation. However, under Ubuntu, the name ubuntu is assigned if no name is defined by the user. M man page Documentation accessible from the shell that describes a command and how it should be used. Minix Operating system that is a rough clone of Unix, created by Professor Andrew Tanenbaum. It was the inspiration for Linux. module Program code that can be inserted or removed from the kernel in order to support particular pieces of hardware or provide certain kernel functions. Drivers under Windows perform the same function. mount To add a file system so that it is integrated (and therefore accessible) within the main file system; applies to external file systems, such as those available across networks, as well as those on the local PC, such as the hard disk or CD/DVD-ROMs. Mozilla Foundation Organization founded by Netscape to create open source Internet software, such as web browsers and e-mail clients; originally based on the Netscape source code. At the time of writing, it produces the Firefox and Camino web browsers, the Thunderbird e-mail and Usenet client, the Bugzilla bug-tracking software, as well as other programs. MySQL Popular and powerful open source database application. See also LAMP. N newbie Term used to describe anyone who is new to Linux and therefore still learning the basics. It s not a derogatory term! See also guru.

504 APPENDIX A GLOSSARY OF LINUX TERMS Kubuntu Version of Ubuntu that substitutes the GNOME desktop environment for KDE. At the time of writing, it is less mature than the standard version of Ubuntu. LAMP Acronym describing a series of programs that work together to provide a complete Linuxbased web-hosting environment. Stands for Linux, Apache, MySQL, and Perl, PHP or Python (the last three in the list are scripting languages; see script). LGPL Lesser GPL; version of the GNU Public License (GPL) in which some use restrictions are slackened at the expense of various freedoms laid down by the main GPL. The LGPL is mostly used for library files. library General term referring to code that programs need to run and that, once in memory, is frequently accessed by many programs (leading to the phrase shared library ). The most common and vital library is glibc (GNU C Library), created by GNU Project, The and the fundamental building block without which Linux could not operate. GNOME relies on the GTK+ libraries, among others. link File system method of assigning additional filenames to a file; also known as a hard link. See also symbolic link. Linux You mean you don t know by now? Linux is what this book is all about. It is a kernel program created by Torvalds, Linus in 1991 to provide an inexpensive operating system for his computer, along with other components. These days, Linux is used to describe the entire operating system discussed in this book, although many argue (perhaps quite rightly) that this is inaccurate, and use the term GNU/Linux instead. local Shorthand referring to the user s PC or a device directly attached to it (as opposed to remote).

APPENDIX A GLOSSARY OF LINUX TERMS ipchains Now deprecated component of version 2.2 of the Linux kernel that allows the creation of network security setups, such as firewalls or port-forwarding arrangements. Note that some distros still prefer to use ipchains. See also iptables. iptables Component of versions 2.4 and 2.6 of the Linux kernel that allows powerful network security setups. Chiefly used in the creation of firewalls, but can be used for more elementary arrange ments such as network address translation (NAT) routers. J job How the BASH shell refers to a running program in order to facilitate administration by the user. journaling File system technology in which integrity is maintained via the logging of disk writes. K KDE K desktop environment; GUI and set of additional programs used on various distros, such as Mandriva and a variation of Ubuntu called Kubuntu. kernel Essential but ordinarily invisible set of programs that run the computer s hardware and provide a platform on which to run software. In the Linux operating system, the kernel is also called Linux, after its creator, Torvalds, Linus. kernel panic Error message that appears when the kernel program in Linux cannot continue to work. In other words, a polite way of indicating a crash or, more often, a problem arising from user misconfiguration. This is most often seen when booting up after making incorrect changes to the system. kludge Community slang describing an inelegant way of making something work, usually not in a way that is generally accepted as being correct. Pronounced kloodge.

502 APPENDIX A GLOSSARY OF LINUX TERMS hacker Term used within the community to describe anyone who enjoys computers and possesses some skill therein, either in a professional capacity or as a hobby. This term is distinct from connotations of maliciously breaking into computers propagated by the media. See also cracker. host Shorthand referring to any computer that acts as a server to another computer. See also client. HP-UX Hewlett-Packard s proprietary form of Unix designed to work on its own hardware platform. Hurd Kernel being developed by GNU Project, The. It s not associated with the Linux kernel in any way. I info Source of documentation accessible from the shell; an alternative to the more established man page system. Also known as Texinfo. init The program that is automatically run after the kernel has finished loading, and therefore early in the boot procedure. It s responsible for effectively starting the operating system. init.d Collection of startup scripts that make up the components of a run level. Under Ubuntu, these are found at /etc/init.d/. Symbolic links to selected init.d scripts are contained in folders within /etc/init.d that are named after run level numbers, such as rc0.d, rc1.d, rc2.d, and so on. initrd Initial RAM disk; system used by the Linux kernel to load modules that are essential for the kernel to be able to boot, such as disk controllers. inode Part of the usually invisible file system structure that describes a file, such as its ownership permissions or file size.

APPENDIX A GLOSSARY OF LINUX TERMS GNU Public License Software license principally created by Stallman, Richard in order to protect software source code against proprietary interests and ensure that it will always be shared. It does this by insisting that any source code covered by the GNU Public License (GPL) must remain licensed under the GPL, even after it has been modified or added to by others. The Linux kernel, as well as much of the software that runs on it, uses the GPL. GPL See GNU Public License. grep Global Regular Expression Print; powerful shell command that lets you search a file or other form of input using regular expressions. Because of the ubiquity of the grep program, many Linux and Unix users refer to searching as grepping. To grep a file is to search through it for a string. group Collection of users under one heading (group name) to facilitate system administration. GRUB GRand Unified Bootloader; boot manager program that offers a menu from which you can choose which operating system you wish to boot. It s needed to load the kernel program and thereby initiate the Linux boot procedure. GUI Graphical user interface; describes the software that provides a graphical system to display data and let you control your PC (usually via a mouse). guru One who is experienced and knowledgeable about Linux/Unix and is willing to share his or her knowledge with others. In a perfect world, every newbie would have his or her own guru. gzip One of the two preferred forms of file compression used under Linux. Files employing gzip compression usually have a .gz file extension. See also bzip2. H hack Ingenious and/or extremely efficient solution to a problem, particularly within the programming world.

500 APPENDIX A GLOSSARY OF LINUX TERMS Free Software Software in which the source code the original listing created by the programmer is available for all to see, share, study, and adapt to their own needs. This differs from the concept of open source because the right of others to further modify the code is guaranteed via the GNU Public License (GPL) software license (or a compatible license). For various reasons, Free Software sometimes does not include the source code (although the software can still be legally decompiled), but this is rare. G gcc GNU Compiler Collection; programs used when creating binary executable files from source code. GID Group ID; numbering system used by the operating system to refer to a group. GIMP GNU Image Manipulation Program; high-powered image-editing program that runs under Linux, Unix, Windows and other operating systems. Often preceded by the definite article: The GIMP. GNOME GNU Network Object Model Environment; a GUI-based desktop environment used by Ubuntu, as well as several other distributions. It uses the GTK+ libraries. See also KDE. GNU GNU s Not Unix; see GNU Project, The. GNU/Linux Another name for the operating system referred to as Linux. The name GNU/Linux gives credit to the vast quantity of GNU Project, The software that is added to the Linux kernel within a distro to make a complete operating system. As such, GNU/Linux is the preferred term of many Free Software advocates. GNU Project, The Organization created by Stallman, Richard in order to further the aims of Free Software and create the body of software that makes up the GNU operating system.

APPENDIX A GLOSSARY OF LINUX TERMS dpkg Shell command that can be used to administer software under Ubuntu and Debian. However, the APT system, which uses dpkg, is the preferred method of installing software. E Emacs Seminal text editor and pseudo-shell beloved by Unix aficionados; can be used for programming tasks, simple word processing, and much more. This editor has cultural significance as one of the core pieces of software offered by GNU Project, The. Emacs was originally developed principally by Stallman, Richard. See also vi. environment Shorthand referring to a user s unique Linux configuration, such as variables that tell the shell where programs are located. F FAT32 File Allocation Table 32-bits; file system offered by Windows 98, Me, 2000, and XP. Linux can both read and write to FAT32 file systems. See also NTFS and VFAT. Firefox Web browser program used under Ubuntu and produced by the Mozilla Foundation. FLOSS Free, Libre, or Open Source Software; used within the community to describe all software or technology that, broadly speaking, adheres to the ethical approach of Open Source software and/or Free Software, as well as its legal guidelines. FOSS Free or Open Source Software; alternative term for FLOSS. free When used to describe software or associated areas of technology, free indicates that the project abides by the ethical (if not legal) guidelines laid down by GNU Project, The. It doesn t indicate that the software is free in a monetary sense; its meaning is quite different from freeware.

498 APPENDIX A GLOSSARY OF LINUX TERMS CVS Concurrent Versioning System; application that allows the latest version of software packages to be distributed over the Internet to developers and other interested parties. D daemon See service. Debian Voluntary organization that produces distributions of Free Software operating systems, including Linux. Because it is a nonprofit organization run by passionate Free Software advocates, it is considered the most ethically sound of all Linux outfits. Many distributions, including Ubuntu, use Debian as the basis for their software because of its claimed reliability and relative simplicity. dependency A way of referring to system files that a program requires in order to run. If the dependencies are not present during program installation, a program might refuse to install. device Linux shorthand describing something on your system that provides a function for the user or that the system requires in order to run. This usually refers to hardware, but it can also describe a virtual device that is created to provide access to a particular Linux function. directory What Windows refers to as a folder; areas on a hard disk in which files can be stored and organized. distribution A collection of software making up the Linux operating system; also known as a distro. The software is usually compiled by either a company or organization. A distribution is designed to be easy to install, administer, and use by virtue of it being an integrated whole. Examples include Ubuntu, SUSE Linux, Red Hat, and Debian. distro Shorthand for distribution. documentation Another way of describing written guides or instructions; can refer to online sources of help as well as actual printed documentation.