Chapter 6 Review Questions

1. When you configure an X server, you need to make changes to configuration files and then start or restart the X server. Which of the following can help streamline this process? A. Shut down X by switching to a runlevel in which X doesn't run automatically, and then reconfigure it and use startx to test X startup. B. Shut down X by booting into single-user mode, and then reconfigure X and use telinit to start X running again. C. Reconfigure X, and then unplug the computer to avoid the lengthy shutdown process before restarting the system and X along with it. D. Use the startx utility to check the X configuration file for errors before restarting the X server. E. Connect the Linux computer's network port directly to the X server, without using any intervening routers, in order to reduce network latency.

1. A. On most Linux systems, some runlevels don't run X by default, so using one of them along with the startx program (which starts X running) can be an effective way to test changes to an X configuration quickly, making option A correct. The telinit program changes runlevels, which is a lengthy process compared to using startx, so option B is incorrect. Unplugging the computer to avoid the shutdown process is self-defeating because you'll have to suffer through a long startup (if you use a non-journaling filesystem), and it can also result in data loss, thus option C is incorrect. The startx utility doesn't check the veracity of an X configuration file; it starts X running from a text-mode login, making option D incorrect. Reconfiguring an X server does not normally require network access; the X server runs on the computer at which you sit. Thus option E is incorrect.

10. To assist an employee who has trouble with keyboard repeat features, you've disabled this function in /etc/X11/xorg.conf. Why might this step not be sufficient for the goal of disabling keyboard repeat? A. GNOME, KDE, or other desktop environment settings for keyboard repeat may override those set in xorg.conf. B. The xorg.conf file has been deprecated; you should instead adjust the /etc/X11/XF86Config file. C. Keyboard settings in xorg.conf apply only to Bluetooth keyboards; you must use usbkbrate to adjust keyboard repeat for USB keyboards. D. You must also locate and reset the DIP switch on the keyboard to disable keyboard repeat. E. The keyboard repeat options in xorg.conf work only if the keyboard's nationality is set incorrectly, which is not often.

10. A. As stated in option A, GNOME, KDE, and other user programs often override the keyboard repeat settings in the X configuration file. Option B has it almost backward; most Linux distributions have abandoned XFree86, and therefore its XF86Config file, in favor of X.org-X11 and its xorg.conf file. Option C is pure fiction; xorg.conf settings apply to all varieties of keyboards, and there is no standard usbkbrate program. Although some keyboards do have hardware switches, they don't affect X's ability to control the keyboard repeat rate, contrary to option D. Although you can set a keyboard's nationality in xorg.conf, this option is independent of the keyboard repeat rate settings, so option E is incorrect.

11. Which of the following programs may be used to provide computer-generated speech for users who have trouble reading computer displays? (Select two.) A. SoX B. Braille C. Orca D. talk E. Emacspeak

11. C, E. The Orca and Emacspeak programs both provide text-to-speech conversion facilities, so options C and E are both correct. Braille is a form of writing that uses bumps or holes in a surface that can be felt by the reader. Although Linux supports Braille output devices, the question specifies computer-generated speech, which Braille is not, so option B is incorrect. SoX (option A) is an audio format converter, but it won't convert from text to speech. The talk program (option D) is an early Unix online text-mode "chat" program, but it has no built-in speech synthesis capabilities.

12. You manage a computer that's located in Los Angeles, California, but the time zone is misconfigured as being in Tokyo, Japan. What procedure can you follow to fix this problem? (Select two.) A. Run hwclock --systohc to update the clock to the correct time zone. B. Delete /etc/localtime, and replace it with an appropriate file from /usr/share/zoneinfo. C. Edit the /etc/tzconfig file so that it specifies North_America/Los_Angeles as the time zone. D. Edit /etc/localtime, and change the three-letter time zone code on the TZ line. E. Use the tzselect program to select a new (Los Angeles) time zone.

12. B, E. Time zones are determined by the /etc/localtime file, so replacing that one with the correct file (a selection is stored in /usr/share/zoneinfo) will fix the problem, making option B correct. (You may also need to edit /etc/timezone or some other file to keep automatic utilities from becoming confused.) Utilities such as tzselect will make these changes for you after prompting you for your location, so option E is also correct. The hwclock program mentioned in option A reads and writes data from the system's hardware clock. Although it relies on time zone data, it can't adjust your system's time zone itself. There is no standard /etc/tzconfig file, although the tzconfig program, like tzselect, can help you set the time zone. Thus, option C is incorrect. The /etc/localtime file is a binary format; you shouldn't attempt to edit it in a text editor, making option D incorrect.

13. You're configuring a Linux system that doesn't boot any other OS. What is the recommended time to which the computer's hardware clock should be set? A. Helsinki time B. Local time C. US Pacific time D. UTC E. Internet time

13. D. Linux, like Unix, maintains its time internally in Coordinated Universal Time (UTC), so setting the computer's hardware clock to UTC (option D) is the recommended procedure for computers that run only Linux. Although Linus Torvalds spent time at the University of Helsinki, Helsinki time (as in option A) has no special place in Linux. Local time (as in option B) is appropriate if the computer dual-boots to an OS, such as Windows, that requires the hardware clock to be set to local time, but this is the second-best option for a Linux-only system. Option C's US Pacific time, like Helsinki time, has no special significance in Linux. Internet time (option E) is an obscure way to measure time that divides each day into 1,000 "beats." It's not a time zone and is not an appropriate way to set your hardware clock.

14. You've developed a script that uses several Linux commands and edits their output. You want to be sure that the script runs correctly on a computer in Great Britain, although you're located elsewhere, since the output includes features such as currency symbols and decimal numbers that are different from one nation to another. What might you do to test this? A. Enter the BIOS, locate and change the location code, reboot into Linux, and run the script. B. Edit /etc/locale.conf, change all the LC_* variables to en_GB.UTF-8, and then reboot and run the script. C. Type export LC_ALL=en_GB.UTF-8, and run the script from the same shell you used to type this command. D. Type locale_set Great_Britain, and run the script from the same shell you used to type this command. E. Type export TZ=:/usr/share/zoneinfo/Europe/London, and run the script from the same shell you used to type this command.

14. C. When set, the LC_ALL environment variable (option C) adjusts all the locale (LC_*) variables, so setting this and then running the script will make the programs that your script uses work as if on a British computer. The BIOS has no location code data, so option A is incorrect. There is no standard /etc/locale.conf file, so option B is incorrect. There is no standard locale_set utility, so option D is incorrect. Although setting the TZ environment variable, as in option E, will set the time zone for your local shell to that for Great Britain, this won't affect the sort of text formatting options noted in the question.

15. Which character set encoding is the preferred method on modern Linux systems? A. UTF-8 B. ASCII C. ISO-8859-1 D. ISO-8859-8 E. ATASCII

15. A. The Unicode Transformation Format 8 (UTF-8) standard can encode characters for just about any language on Earth, while looking just like ordinary ASCII to programs that only understand ASCII. Thus UTF-8 (option A) is the preferred method for character encoding when a choice is possible. ASCII (option B) is an old standard that's adequate for English and a few other languages, but it lacks some or all characters needed by most languages. ISO-8859 (options C and D) is a standard that extends ASCII, but it requires separate encodings for different languages and so it is awkward when a computer must process data from multiple languages. ATASCII (option E) is a variant of ASCII used in the 1980s by Atari for its home computers; it's obsolete and inadequate today.

16. Which of the following describes the function of a smart filter? A. It improves the legibility of a print job by adding font smoothing to the text. B. It detects information in print jobs that may be confidential as a measure against industrial espionage. C. It sends email to the person who submitted the print job, obviating the need to wait around the printer for a printout. D. It detects and deletes prank print jobs that are likely to have been created by troublemakers trying to waste your paper and ink. E. It detects the type of a file and passes it through programs to make it printable on a given model of printer.

16. E. The smart filter makes a print queue "smart" in that it can accept different file types (plain text, PostScript, graphics, and so on) and print them all correctly, as in option E. Font smoothing is useful on low-resolution computer monitors, but not on most printers, and adding font smoothing is not a function of a smart filter, so option A is incorrect. A smart filter doesn't detect confidential information (option B) or prank print jobs (option D). The lpr program can be given a parameter to email a user when the job finishes (option C), but the smart filter doesn't do this.

17. What information about print jobs does the lpq command display? (Select two.) A. The name of the application that submitted the job B. A numerical job ID that can be used to manipulate the job C. The amount of ink or toner left in the printer D. The username of the person who submitted the job E. The estimated time to finish printing the job

17. B, D. The job ID (option B) and job owner (option D) are both displayed by lpq. Unless the application embeds its own name (option A) in the filename, that information won't be present. Most printers lack Linux utilities to query ink or toner status (option C); certainly lpq can't do this. Although knowing when your job will finish printing (option E) would be handy, providing this information is well beyond lpq's capabilities.

18. You've submitted several print jobs, but you've just realized that you mistakenly submitted a huge document that you didn't want to print. Assuming that you can identify the specific job, that it's not yet printing, and that its job ID number is 749, what command would you type to delete it from the okidata print queue? A. The answer depends on whether you're using BSD, LPD, LPRng, or CUPS. B. Type lpdel -Pokidata 749. C. Type lprm -Pokidata 749. D. Type cupsdisable -Pokidata 749. E. None of the above; the task is impossible.

18. C. The lprm command (option C) deletes a job from the print queue. It can take the -Pqueue option to specify the queue and a print job number or various other parameters to specify which jobs to delete. BSD LPD, LPRng, and CUPS all implement the lprm command, so you can use it with any of these systems, making option A incorrect. Option B presents the correct syntax but the wrong command name; there is no standard lpdel command. The cupsdisable command can be used to disable the whole queue but not to delete a single print job, so option D is incorrect. Because option C is correct, option E obviously is not.

19. Which of the following is generally true of Linux programs that print? A. They send data directly to the printer port. B. They produce PostScript output for printing. C. They include extensive collections of printer drivers. D. They can print only with the help of add-on commercial programs. E. They specify use of the Verdana font.

19. B. PostScript is the de facto printing standard for Unix and Linux programs, as specified in option B. Linux programs generally do not send data directly to the printer port (option A); on a multitasking, multiuser system, this would produce chaos because of competing print jobs. Although a few programs include printer driver collections, most forgo this in favor of generating PostScript, making option C incorrect. Printing utilities come standard with Linux; add-on commercial utilities aren't required, so option D is incorrect. Verdana is one of several "web fonts" released by Microsoft. Although many Linux programs can use Verdana for printing if the font is installed, most Linux distributions don't install Verdana by default, and few Linux programs use it for printing by default even if it's installed, so option E is not correct.

2. Which of the following summarizes the organization of the X configuration file? A. The file contains multiple sections, one for each screen. Each section includes subsections for individual components (keyboard, video card, and so on). B. Configuration options are entered in any order desired. Options relating to specific components (keyboard, video card, and so on) may be interspersed. C. The file begins with a summary of individual screens. Configuration options are preceded by a code word indicating the screen to which they apply. D. The file is broken into sections, one or more for each component (keyboard, video card, and so on). The file also has one or more sections that define how to combine the main sections. E. The file is a rare binary configuration file that must be accessed using SQL database tools.

2. D. The XF86Config and xorg.conf file design enables you to define variants or multiple components and easily combine or recombine them as necessary, using the structure specified in option D. Options A, B, and C all describe fictitious structures. Option E is incorrect because the X.org-X11 and XFree86 configuration files use a text-mode structure, not a binary structure.

20. What tool might you use to print a four-page PostScript file on a single sheet of paper? A. PAM B. mpage C. 4Front D. route E. 411toppm

20. B. The mpage utility (option B) prints multiple input pages on a single output page, so it's ideally suited to the specified task. PAM (option A) is the Pluggable Authentication Modules, a tool for helping to authenticate users. 4Front (option C) is the name of a company that produces commercial sound drivers for Linux. The route command (option D) is used to display or configure a Linux routing table. The 411toppm program (option E) converts files from Sony's 411 image file format to the PPM image file format; it doesn't do the specified task.

3. A monitor's manual lists its range of acceptable synchronization values as 27kHz-96kHz horizontal and 50Hz-160Hz vertical. What implications does this have for the resolutions and refresh rates the monitor can handle? A. The monitor can run at up to 160Hz vertical refresh rate in all resolutions. B. The monitor can handle up to 160Hz vertical refresh rate depending on the color depth. C. The monitor can handle up to 160Hz vertical refresh rate depending on the resolution. D. The monitor can handle vertical resolutions of up to 600 lines (96,000 ÷ 160), but no more. E. The monitor can handle horizontal resolutions of up to 600 columns (96,000 ÷ 160), but no more.

3. C. The vertical refresh rate range includes a maximum value, but that value may be reduced when the resolution and vertical refresh rate would demand a higher horizontal refresh rate than the monitor can handle. Thus, option C is correct. Since the resolution affects the maximum refresh rate, option A is incorrect. The color depth is irrelevant to resolution and refresh rate calculations, so option B is incorrect. The computations shown in options D and E are bogus, making these options incorrect.

4. In what section of XF86Config or xorg.conf do you specify the resolution that you want to run? A. In the ServerLayout section, using the Screen option B. In the Monitor section, using the Modeline option C. In the Device section, using the Modeline option D. In the DefaultResolution section, using the Define option E. In the Screen section, subsection Display, using the Modes option

4. E. Option E describes the correct location for this option. The ServerLayout section (referenced in option A) combines all of the other options together but doesn't set the resolution. The Modeline option in the Monitor section (as described in option B) defines one possible resolution, but there may be several Modeline entries defining many resolutions, and there's no guarantee that any of them will be used. The Modeline option doesn't exist in the Device section (as suggested by option C), nor is that section where the resolution is set. There is no DefaultResolution section (as referenced in option D).

5. What is an advantage of a font server? A. It provides faster font displays than are otherwise possible. B. It can simplify font maintenance on a network with many X servers. C. It's the only means of providing TrueType support for XFree86 4.x. D. It enables the computer to turn a bitmapped display into an ASCII text file. E. It enables X to use font smoothing, which isn't possible with core fonts.

5. B. By maintaining fonts on one font server and pointing other X servers to that font server, you can reduce the administrative cost of maintaining the fonts on all of the systems, so option B is correct. Font servers don't produce faster font displays than X's local font handling; if anything, the opposite is true. Thus, option A is incorrect. XFree86 4.x supports TrueType fonts directly, so option C is incorrect. Converting a bitmapped display into ASCII text is a function of optical character recognition (OCR) software, not a font server, so option D is incorrect. Neither X core fonts nor a font server handles font smoothing; for that, you need Xft. Thus, option E is incorrect.

6. What methods do Linux distributions use to start X automatically when the system boots? (Select two.) A. Start an XDMCP server from the Start folder. B. Start an XDMCP server from an ~/.xinitrc script. C. Start an XDMCP server via a system startup script. D. Start an XDMCP server via a boot manager. E. Start an XDMCP server from init.

6. C, E. XDMCP servers are typically launched either from a system startup script or by init (as specified in /etc/inittab), as described in options C and E. The XDMCP server then starts X. The Start folder mentioned in option A is a Windows construct, not a Linux construct. The ~/.xinitrc script mentioned in option B is an X login script used when starting X from the command line via startx; it's not used to start X automatically when the system boots. A boot manager, as described in option D, launches the kernel; it doesn't directly start X, so option D is incorrect.

7. How would you change the text displayed by XDM as a greeting? A. Click Configure ➣ Greeting from the XDM main menu, and edit the text in the resulting dialog box. B. Pass greeting="text" as a kernel option in the boot loader, changing text to the new greeting. C. Edit the /etc/X11/xorg.conf file, and change the Greeting option in the xdm area. D. Run xdmconfig, and change the greeting on the Login tab. E. Edit the /etc/X11/xdm/Xresources file, and change the text in the xlogin*greeting line.

7. E. The XDM greeting is a resource set in the /etc/X11/xdm/Xresources file, so option E is correct. XDM doesn't offer many options on its main screen and certainly not one to change its greeting, as described in option A. The kernel doesn't directly handle the login process, nor does it pass options directly to XDM, so option B is incorrect. Although the xorg.conf file mentioned in option C is real, this file provides no XDM configuration options because XDM is a separate program from the X server. There is no standard xdmconfig program, as mentioned in option D.

8. Which of the following features do KDM and GDM provide that XDM doesn't? A. An encrypted remote X-based access ability, improving network security B. The ability to accept logins from remote computers, once properly configured C. The ability to select the login environment from a menu on the main login screen D. A login screen that shows the username and password simultaneously rather than sequentially E. An option to log into text mode if X should fail to start

8. C. KDM and GDM add many features, one of which is a menu that enables users to select their desktop environment or window manager when they log in rather than specifying it in a configuration file, as option C states. Option A describes one of the advantages of the Secure Shell (SSH) as a remote-access protocol. Option B describes a feature common to all three XDMCP servers. Option D describes the way both KDM and XDM function; GDM is the one that presents username and password fields in series rather than simultaneously. Although a failure of X to start usually results in a fallback to a text-mode login, this feature is not provided by the XDMCP server, so option E is incorrect.

9. Which of the following commands tells the X server to accept connections from penguin.example.com? A. xhost +penguin.example.com B. export DISPLAY=penguin.example.com:0 C. telnet penguin.example.com D. xaccess penguin.example.com E. ssh penguin.example.com

9. A. The xhost command controls various aspects of the local X server, including the remote computers from which it will accept connections, making option A correct. Option B sets the DISPLAY environment variable, which doesn't directly affect the X server (it does tell X clients which X server to use). Option C initiates a text-mode remote login session with penguin.example.com. Option D's xaccess is a fictitious program. Although logging into penguin.example.com via ssh may also initiate an X tunnel, this isn't guaranteed, and such a tunnel doesn't cause the local X server to accept direct connections from the remote computer, so option E is incorrect.