Linux Bible. Christopher Negus
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Название: Linux Bible

Автор: Christopher Negus

Издательство: John Wiley & Sons Limited

Жанр: Зарубежная образовательная литература

Серия:

isbn: 9781118999882

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СКАЧАТЬ the Alt key, and press the Tab key. You see reduced versions of all your windows in a strip in the middle of your screen, with the current window highlighted in the middle. Still holding the Alt key, press Tab or Shift+Tab to move forward or backward through the windows. Release the keys when the one you want is highlighted.

      ● Scale and separate workspaces– Hold Ctrl+Alt, and press the down arrow key to see reduced images of the workspace shown on a strip. Still holding Ctrl+Alt, use the right and left arrow keys to move among the different workspaces. Release the keys when the workspace you want is highlighted.

      ● Send current window to next workspace– Hold Ctrl+Alt+Shift keys together, and press the left and right arrow keys. The next workspace to the left or right, respectively, appears on the current desktop.

      ● Slide windows around– Press and hold the left mouse button on the window title bar, and then press the left, right, up, or down arrow keys to slide the current window around on the screen.

      If you get tired of wobbling windows and spinning cubes, you can easily turn off the AIGLX 3D effects and return to using Metacity as the window manager. Select System arr Preferences arr Desktop Effects again, and toggle off the Enable Desktop Effects button to turn off the feature.

      If you have a supported video card, but find that you cannot turn on the Desktop Effects, check that your X server started properly. In particular, make sure that your /etc/X11/xorg.conf file is properly configured. Make sure that dri and glx are loaded in the Module section. Also, add an extensions section anywhere in the file (typically at the end of the file) that appears as follows:

      Another option is to add the following line to the /etc/X11/xorg.conf file in the Device section:

      The XAANoOffscreenPixmaps option improves performance. Check your /var/log/Xorg.log file to make sure that DRI and AIGLX features were started correctly. The messages in that file can help you debug other problems as well.

      Summary

      The GNOME desktop environment has become the default desktop environment for many Linux systems, including Fedora and RHEL. The GNOME 3 desktop (now used in Fedora and Red Hat Enterprise Linux 7) is a modern, elegant desktop, designed to match the types of interfaces available on many of today's mobile devices. The GNOME 2 desktop (used through RHEL 6) provides a more traditional desktop experience.

      Besides GNOME desktops, you can try out other popular and useful desktop environments. The K Desktop Environment (KDE) offers many more bells and whistles than GNOME and is used by default in several Linux distributions. Netbooks and live CD distributions sometimes use the LXDE or Xfce desktops.

      Now that you have a grasp of how to get and use a Linux desktop, it's time to start digging into the more professional administrative interfaces. Chapter 3 introduces you to the Linux command-line shell interface.

      Exercises

      Use these exercises to test your skill in using a GNOME desktop. You can use either a GNOME 2.x (Red Hat Enterprise Linux up until RHEL 6.x) or GNOME 3.x (Fedora 16 or later or Ubuntu up to 11.10, or later using the Ubuntu GNOME project) desktop. If you are stuck, solutions to the tasks for both the GNOME 2 and GNOME 3 desktops are shown in Appendix B.

      1. Obtain a Linux system with either a GNOME 2 or GNOME 3 desktop available. Start the system, and log in to a GNOME desktop.

      2. Launch the Firefox web browser, and go to the GNOME home page (http://gnome.org).

      3. Pick a background you like from the GNOME art site (http://gnome-look.org/), download it to your Pictures folder, and select it as your current background.

      4. Start a Nautilus File Manager window, and move it to the second workspace on your desktop.

      5. Find the image you downloaded to use as your desktop background, and open it in any image viewer.

      6. Move back and forth between the workspace with Firefox on it and the one with the Nautilus file manager.

      7. Open a list of applications installed on your system, and select an image viewer to open from that list. Use as few clicks or keystrokes as possible.

      8. Change the view of the windows on your current workspace to smaller views of those windows you can step through. Select any window you like to make it your current window.

      9. From your desktop, using only the keyboard, launch a music player.

      10. Take a picture of your desktop, using only keystrokes.

Part II

      Becoming a Linux Power User

Chapter 3

      Using the Shell

      Before icons and windows took over computer screens, you typed commands to interact with most computers. On UNIX systems, from which Linux was derived, the program used to interpret and manage commands was referred to as the shell.

      No matter which Linux distribution you are using, you can always count on the fact that the shell is available to you. It provides a way to create executable script files, run programs, work with filesystems, compile computer code, and manage the computer. Although the shell is less intuitive than common graphic user interfaces (GUIs), most Linux experts consider the shell to be much more powerful than GUIs. Shells have been around a long time, and many advanced features that aren't available from the desktop can be accessed by running shell commands.

      The Linux shell illustrated in this chapter is called the bash shell, which stands for Bourne Again Shell. The name is derived from the fact that bash is compatible with the one of the earliest UNIX shells: the Bourne shell (named after its creator Stephen Bourne, and represented by the sh command).

      Although bash is included with most distributions, and considered a standard, other shells are available, including the C shell (csh), which is popular among BSD UNIX users, and the Korn shell (ksh), which is popular among UNIX System V users. Ubuntu uses the dash shell, by default, which is designed to perform faster than the bash shell. Linux also has a tcsh shell (an improved C shell) and an ash shell (another Bourne shell look-alike).

      The odds are strong that the Linux distribution you are using has more than one shell installed by default and available for your use. This chapter, however, focuses primarily on the bash shell. That is because the Linux distributions featured in this book, Fedora and Red Hat Enterprise Linux, both use the bash shell by default. The bash shell can also easily be added to Ubuntu.

      The following are a few major reasons to learn how to use the shell:

      ● You will know how to get around any Linux or other UNIX-like system. For example, I can log in to my Red Hat Enterprise Linux web server, my home multimedia server, my home router, or my wife's Mac and explore and use any of those computer systems from a shell. I can even log in and run commands on my Android phone. They all run Linux or similar systems on the inside.

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