S

Samba

Program that recreates under Unix or Linux the Microsoft SMB-based system of sharing files, printers, and other computer resources across a network. It allows Linux to become a file or printer server for Linux and Windows computers, and also allows a Linux client to access a Windows-based server.

SaX2

SUSE Advanced X configuration tool, version 2; GUI-based software by which the keyboard, mouse, display and other aspects of X can be configured.

scalable

Term describing the ability of a single computer program to meet diverse needs, regardless of the scale of the potential uses. The Linux kernel is described as being scalable because it can run supercomputers, as well as handheld computers and home entertainment devices.

script

Form of computer program consisting of a series of commands in a text file. Most shells allow some form of scripting, and entire programming languages such as Perl are based around scripts. Shell scripts are usually created to perform trivial tasks or ones that frequently interact with the user. Shell scripts have the advantage that they can be frequently and easily modified. The Linux boot process relies on several complex scripts to configure essential system functions such as networking and the GUI. See also init.465

server

(1) Type of computer designed to share data with other computers over a network.

(2) Software that runs on a computer and is designed to share data with other programs on the same PC or with other PCs across a network.

service

Background program that provides vital functions for the day-to-day running of Linux; also known as a daemon. Services are usually started when the computer boots up and as such are constituent parts of a run level.

shell

Broadly speaking, any program that creates an operating environment in which you can control your computer. The SUSE desktop can be seen as a shell, for example. However, it’s more commonly understood within Unix and Linux circles as a program that lets you control the system using commands entered at the keyboard. In this context, the most common type of shell in use on Linux is BASH.

SMB

Server Message Block; network technology for sharing files, printers, and other resources. See Samba.

Solaris

Form of Unix sold by Sun Microsystems; runs on proprietary hardware systems as well as on commodity systems based on Intel and AMD processors.

source code

The original program listing created by a programmer. Most programs that you download are precompiled—already turned into binary executables ready for general use—unless you specifically choose to download and compile the source code of a program yourself.

SSH

Secure SHell; program that lets you access a Linux/Unix computer across the Internet. SSH encrypts data sent and received across the link.

SSL

Secure Sockets Layer; form of network data transfer designed to encrypt information for security purposes. It’s used online for certain web sites and also within Linux for certain types of secure data exchange.

Stallman, Richard M.

Legendary hacker who founded GNU Project, The and created the concept of copyleft, as well as the software license that incorporates it: the GPL. See also Torvalds, Linus.

standard error

Linux and Unix shorthand for the error output provided by a command.

standard input

Linux and Unix shorthand for the device usually used to provide input to the shell. For the majority of desktop PC users, this refers to the keyboard.

standard output

Linux and Unix shorthand for the device usually used to display output from a command. For the majority of desktop PC users, this refers to the screen.

string

A word, phrase, or sentence consisting of letters, numbers, or other characters that is used within a program and is often supplied by the user.

SUSE Linux

Company owned by Novell that produces its own distribution of Linux. A version of SUSE Linux is provided with this book.

SVG

Scalable Vector Graphics; vector graphics technology. SVG is actually an XML markup language designed to create 2D graphics, increasingly used for Linux desktop icons.

swap

Area of the hard disk that the Linux kernel uses as a temporary memory storage area. Desktop or server Linux differs from Windows in that it usually requires a separate hard disk partition in which to store the swap file.

symbolic link

Type of file akin to a Windows shortcut. Accessing a symbolic link file routes the user through to an actual file. See also link.

sysadmin

Systems administrator; a way of describing the person employed within a company to oversee the computer systems. In such an environment, the sysadmin usually is the root user of the various computers.

System V

Variant of Unix used as a foundation for modern forms of proprietary Unix.