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83Chapter 3Getting into the Desktop .Desktop icons The icons on the desktop are usually, by default, those thatenable you to access removable media (CD, floppy disk, etc.), throw out files(trash icon), and visit your home directory. In KNOPPIX, the KDE desktop alsohas a nice feature that lets you access your hard disk partitions directly fromicons on the desktop. .Konqueror file manager Konqueror is the file manager window used withKDE desktops. It not only can be used to manage files but also to display Webpages. Konqueror is described in detail later in this chapter. .Desktop menu Right-click the desktop to see a menu of common actions totake. The menu provides a quick way to access your bookmarks; create newfolders, files, or devices (with devices, you re actually choosing to mount adevice on a particular part of the file system); straighten up your windows oricons; configure the desktop; and log out of your KDE session. To navigate the KDE desktop, you can use the mouse or key combinations. Theresponses from the desktop to your mouse depend on which button you click andwhere the mouse pointer is located. Table 3-1 shows the results of clicking eachmouse button with the mouse pointer placed in different locations. (You canchange any of these behaviors from the Windows Behavior panel on the KDEControl Center. From the KDE menu, select Settings.Control Center, and thenchoose the Window Behavior selection under the Desktop heading.) Figure 3-3:The KDE desktop includes a panel, desktop icons, and menus.

82Part ILinux First Stepsto the next. With KDE, you can do all those things and much more. For example, you can: .Drag-and-drop a document from a folder window (Konqueror) to the Trash icon(to get rid of it) or on a OpenOffice.org Writer icon (to open it for editing). .Right-click an image file (JPEG, PNG, etc.), and the OpenWith menu lets youchoose to open the file using an image viewer (KView), editor (GIMP), slideshow viewer (Kuickshow), or other application. To make more applications available to you in the future, KDE provides a platformfor developers to create programs that easily share information and detect how todeal with different data types. The things you can do with KDE grow every day. KDE is the default desktop environment for SUSE, KNOPPIX, and several other Linuxsystems. It is available with Red Hat Enterprise Linux and Fedora Core but is notinstalled by default when they are installed as desktop systems (you need to do anEverything install or to select to add KDE specifically in those cases). KDE also hasa different look-and-feel in Red Hat systems than it does from implementation onother systems that deliver KDE desktops. The following section describes how to get started with KDE. This includes usingthe KDE Setup wizard, maneuvering around the desktop, managing files, and addingapplication launchers. In this chapter, KNOPPIX is the reference model for the KDE descriptions. BecauseKDE is very configurable, there may be some differences in these descriptions forKDE in other Linux systems. Using the KDE DesktopKDE as it s delivered with KNOPPIX uses a lot of the design elements that come fromthe KDE project, so it s pretty easy to distinguish from other desktop environments. The look-and-feel has similarities to both Windows and Macintosh systems. Figure 3-3shows an example of the KDE desktop in KNOPPIX: Some of the key elements of the KDE desktop include: .Panel The KDE panel (shown along the bottom of the screen) includes itemsthat enable you to launch applications and to see minimized representations ofactive windows, applets, and virtual desktops. A K icon on the left side of thepanel is used to represent the main menu on a KDE desktop. In KNOPPIX, thaticon is followed by a KNOPPIX-specific menu (it looks like a squished penguin) and other icons to launch common applications (the file manager, Terminalwindow, Web browser, and office applications). Four virtual desktops (shown inlittle boxes numbered 1, 2, 3, and 4) are available by clicking on the number ofthe virtual desktop you want to display. Applets (on the right side of the panel) in KNOPPIX let you change your keyboard, set screen resolution, adjust audiocontrols, and view the time. Note08_

81Chapter 3Getting into the DesktopBoot to a Text PromptInstead of a nice graphical screen with pictures and colors, you might see a loginprompt that looks like this: Welcome to XYZ Linuxyourcomputer login: This is the way all UNIX and older Linux systems used to appear on the screenwhen they booted up. Now this is the login prompt that is typical for a systemthatis installed as a server or, for some reason, was configured not to start anXdisplay manager for you to log in. Run level 3 boots to a plain-text login promptinmultiuser mode. Just because you have a text prompt doesn t necessarily mean you can start a desk- top environment. Many Linux experts boot to a text prompt because they only wantto use the GUI on occasion. However, if X and the necessary other desktop compo- nents are installed on your computer, you can typically start the desktop after youlog in by typing the following command: $ startxThe default desktop environment starts up, and you should be ready to go. Whatyou do next depends on whether you have a KDE, GNOME, or some sort of home- spun desktop environment. In most cases, the GUI configuration you do during installation for your video cardand monitor gets you to a working desktop environment. If, for some reason, thescreen is unusable when you start the desktop, you need to do some additionalconfiguration. The Configuring Your Own Desktop section later in this chapterdescribes some tools you can use to get your desktop working. K Desktop Environment (KDE) The KDE was created to bring a high-quality desktop environment to UNIX (andnow Linux) workstations. Integrated within KDE are tools for managing files, win- dows, multiple desktops, and applications. If you can work a mouse, you can learnto navigate the KDE desktop. The lack of an integrated, standardized desktop environment once held back Linuxand other UNIX systems from acceptance on the desktop. While individual appli- cations ran well, you mostly could not drag-and-drop files or other items betweenapplications. Likewise, you couldn t open a file and expect the machine to launchthe correct application to deal with it or save your windows from one login sessionNote08_

80Part ILinux First StepsYou can just enter your login (username) and password to start up your personaldesktop environment. Your selected desktop environment KDE or GNOME comes up ready for you to use. Although the system defines a desktop environmentby default, you can typically change desktop environments on those Linux systems, such as Fedora, that offer both KDE and GNOME. X display managers can enable you to do a lot more than just get to your desktop. Although different graphical login screens offer different options, here are some youmay encounter: .Session Look for a Session button on the login screen (such as the one thatcomes with Fedora). From there, you can choose to start your login sessionwith a GNOME, KDE, or Failsafe environment. (Failsafe simply opens a Terminalwindow so, presumably, you can make a quick fix to the system without start- ing up a whole desktop environment.) .Language Linux systems that are configured to start multiple languagesmay give you the opportunity to choose a language (other than the defaultlanguage) to boot into. For this to work, however, you must have installedsupport for the language you choose. .Reboot or Shutdown There s no need to log in if all you want to do is turnoff or restart your computer. Most graphical login screens offer you the optionof rebooting or shutting down the machine from that screen. If you don t like the way the graphical login screen looks, or just want to assertgreater control over how it works, there are many ways of configuring and securingX graphical login screens. Later, once you are logged in, you can use the followingtools (as root user) to configure the login screen: .KDE Login Manager From the KDE control center, you can modify your KDEdisplay manager using the Login Manager screen (from KDE control center, select System Administration.Login Manager). You can change logos, back- grounds, color schemes, and other features related to the look-and-feel of thelogin screen. .GNOME Login Manager The GNOME display manager (gdm) comes with aLogin Screen Setup utility (from the desktop run the gdmconfigcommand asroot user). From the Login Screen Setup window, you can select the GraphicalGreeter tab and choose a whole different theme for the login manager. On theSecurity tab, you may notice that all TCP connections to the X server are dis- allowed. Don t change this selection because no processes other than thosehandled directly by your display manager should be allowed to connect to thelogin screen. After your login and password have been accepted, the desktop environment con- figured for your user account starts up. Users can modify their desktop environ- ments to suit their tastes (even to the point of changing the entire desktopenvironment used).

79Chapter 3Getting into the Desktopinitdefaultline as you please between 3 and 5 (don t use other numberunless you know what you are doing, and never use 0 or 6). Because graphical login screens are designed to be configurable, you often find thatthe distribution has its own logo or other graphical elements on the login screen. For example, Figure 3-1 shows a basic graphical login panel displayed by the kdmgraphical display manager. Figure 3-1:A simple KDE display manager(kdm) login screen includes a clock, loginname list, and a few menu selections. With Red Hat s Fedora Core Linux, the default login screen is based on the GNOMEdisplay manager (gdm). Figure 3-2 shows the Fedora Core graphical login screen. Figure 3-2:The Fedora Project login screen is based on gdm.

78Part ILinux First Steps .GNOME Desktop Environment (www.gnome.org) GNOME is a more stream- lined desktop environment. It includes a smaller feature set than KDE andruns faster in many lower-memory systems. Some think of GNOME as a morebusiness-oriented desktop. It s the default desktop for Red Hat Linux systemssuch as Fedora and RHEL. .X and a window manager (X.orgor XFree86.org+ WM) You don t need afull-blown desktop environment to operate Linux from a GUI. The most basic, reasonable way of using Linux is to simply start the X Window System serverand a window manager of your choice (there are dozens to choose from). Manyadvanced users go this route because it can offer more flexibility in how theyset up their desktops. The truth is that most X applications run in any of the desktop environments justdescribed (provided that proper libraries are included with your Linux distribution). So you can choose a Linux desktop based on the performance, customization tools, and controls that best suit you. Each of those three types of desktop environmentsare described in this chapter. Starting the DesktopBecause the way that you start a desktop in Linux is completely configurable, differ- ent distributions offer different ways of starting up the desktop. Once your Linuxdistribution is installed, it may just boot to the desktop, offer a graphical login, oroffer a text-based login. Bootable Linux systems (which don t have to be installed atall) typically just boot to the desktop. Boot to the DesktopSome bootable Linux systems boot right to a desktop without requiring you to login, so that you can immediately start working with Linux. KNOPPIX is an example ofa distribution that boots straight to a Linux desktop from a CD. That desktop systemusually runs as a particular username (such as knoppix, in the case of the KNOPPIXdistribution). To perform system administration, you have to switch to the adminis- trator s account temporarily (using the suor sudocommand). Boot to Graphical LoginMost desktop Linux systems that are installed on your hard disk boot up to a graphical login screen. Although the X display manager (xdm) is the basic displaymanager that comes with the X Window System, KDE and GNOME each have theirown graphical display managers that are used as login screens (kdm and gdm, respectively). So chances are that you will see the login screen associated withKDEor GNOME (depending on which is the default on your Linux). When Linux starts up, it enters into what is referred to as a run level or systemstate. Typically, a system set to start at run level 5 boots to a graphical loginprompt. A system set to run level 3 boots to a text prompt. The run level is set bythe initdefaultline in the /etc/inittabfile. Change the number on theNote08_

Getting into the DesktopIn the past few years, graphical user interfaces (GUIs) available for Linux have become as easy to use as thoseonthe Apple Mac or Microsoft Windows systems. With theseimprovements, even a novice computer user can start usingLinux without needing to have an expert standing by. You don t need to understand the underlying framework ofthe X Window System, window managers, widgets, and what- nots to get going with a Linux desktop system. That s why Istart by explaining how to use the two most popular desktopenvironments: KDE (K desktop environment) and GNOME. After that, if you want to dig deeper, I tell you how you can puttogether your own desktop by discussing how to choose yourown X-based window manager to run in Linux. Understanding Your DesktopWhen you install Linux distributions such as Fedora Core, SUSE, and Mandrakelinux, you have the option to chooseadesktop environment. Distributions such as Gentoo andDebian GNU/Linux give you the option to go out and get what- ever desktop environment you want (without particularlyprompting you for it). When you are given the opportunitytoselect a desktop during installation, your choices usuallyinclude one or more of the following: .K Desktop Environment (www.kde.org) In additionto all the features you would expect to find in a completedesktop environment (window managers, toolbars, pan- els, menus, keybindings, icons, and so on), KDE has manybells and whistles available. Applications for graphics, multimedia, office productivity, games, system adminis- tration, and many other features have been integrated towork smoothly with KDE, which is the default desktopenvironment for SUSE, KNOPPIX, and various other Linuxdistributions. 33CHAPTER …In This ChapterUnderstandingyourdesktopUsing the K desktopenvironmentUsing the GNOMEdesktop environmentConfiguring yourown desktop …

75Chapter 2Running Commands from the ShellPutting a number in front of most commands just repeats those commands. At thispoint, you should be fairly proficient at using the vicommand. When you invoke vi in many Linux systems, you re actually invoking the vim texteditor, which runs in vi compatibility mode. Those who do a lot of programmingmight prefer vim because it shows different levels of code in different colors. vimhas other useful features, such as the capability to open a document with the cur- sor at the same place where it was when you last exited that file. SummaryWorking from a shell command line within Linux may not be as simple as using a GUI, but it offers many powerful and flexible features. This chapter explains how to findyour way around the shell in Linux and provides examples of running commands, including recalling commands from a history list, completing commands, and joiningcommands. The chapter describes how shell environment variables can be used to store andrecall important pieces of information. It also teaches you how to modify shell con- figuration files to tailor the shell to suit your needs. Finally, this chapter shows youhow to use the Linux file system to create files and directories, use permissions, and work with files (moving, copying, and removing them), and how to edit textfiles from the shell using the vicommand. … Note07_

74Part ILinux First StepsUsing Numbers with CommandsYou can precede most vi commands with numbers to have the command repeatedthat number of times. This is a handy way to deal with several lines, words, or char- acters at a time. Here are some examples: CommandDescription3dwDeletes the next three words. 5clChanges the next five letters (that is, removes the letters and entersinput mode). 12jMoves down 12 lines. Exploring Other Text EditorsDozens of text editors are available to use with Linux. Here are a few that might be in yourLinux distribution that you can try out if you find vi to be too taxing: Text EditorDescriptiongeditThe GNOME text editor that runs in the GUI. jedThis screen-oriented editor was made for programmers. Using colors, jedcan highlight code you create so you can easily read the code and spotsyntax errors. Use the Alt key to select menus to manipulate your text. joeThe joe editor is similar to many PC text editors. Use control and arrow keysto move around. Type Ctrl+Cto exit with no save or Ctrl+Xto save and exit. kateA nice-looking editor that comes in the kdebase package. It has lots of bellsand whistles, such as highlighting for different types of programminglanguages and controls for managing word wrap. keditA GUI-based text editor that comes with the KDE desktop. mceditWith mcedit, function keys help you get around, save, copy, move, anddelete text. Like jed and joe, mcedit is screen-oriented. neditAn excellent programmer s editor. You need to install the optional neditpackage to get this editor. If you use ssh to log in to other Linux computers on your network, you can use any editorto edit files. A GUI-based editor will pop up on your screen. When no GUI is available, youwill need a text editor that runs in the shell, such as vi, jed, or joe.

73Chapter 2Running Commands from the Shell .Ctrl+F Page ahead, one page at a time. .Ctrl+B Page back, one page at a time. .Ctrl+D Page ahead 1/2 page at a time. .Ctrl+U Page back 1/2 page at a time. .G Go to the last line of the file. .1G Go to the first line of the file. (Use any number to go to that line inthefile.) Searching for TextTo search for the next occurrence of text in the file, use either the slash (/) orthequestion mark (?) character. Follow the slash or question mark with a pattern(string of text) to search forward or backward, respectively, for that pattern. Withinthe search, you can also use metacharacters. Here are some examples: ./hello Searches forward for the word hello. .?goodbye Searches backward for the word goodbye. ./The.*foot Searches forward for a line that has the word Thein it andalso, after that at some point, the word foot. .?[pP]rint Searches backward for either printor Print.Remember that casematters in Linux, so make use of brackets to search for words that could havedifferent capitalization. The vi editor was originally based on the ex editor, which didn t let you work in full-screen mode. However, it did enable you to run commands that let you find andchange text on one or more lines at a time. When you type a colon and the cursorgoes to the bottom of the screen, you are essentially in ex mode. Here is an exampleof some of those ex commands for searching for and changing text. (I chose thewords Localand Remoteto search for, but you can use any appropriate words.) .:g/Local Searches for the word Localand prints every occurrence of thatline from the file. (If there is more than a screenful, the output is piped to themorecommand.) .:s/Local/Remote Substitutes Remotefor the word Localon the current line. .:g/Local/s//Remote Substitutes the first occurrence of the word Localon every line of the file with the word Remote. .:g/Local/s//Remote/g Substitutes every occurrence of the word Localwith the word Remotein the entire file. .:g/Local/s//Remote/gp Substitutes every occurrence of the word Localwith the word Remotein the entire file and then prints each line so that youcan see the changes (piping it through moreif output fills more than one page).